EPA-650/2-74-048
MAY 1974
Environmental Protection Technology Series
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EPA-650/2-74-048
DEVELOPMENT OF AN APPROACH
TO IDENTIFICATION OF EMERGING
TECHNOLOGY AND DEMONSTRATION
OPPORTUNITIES
by
H. Nack. K. Murthy, E. Stambaugh, H. Carlton, and G.R. Smithson, Jr,
Battelle-~Columbus Laboratories
505 King Avenue,
Columbus, Ohio 43201
Grant No. R-802291
ROAP No. 21AFH-016
Program Element No. 1AB015
EPA Project Officer: W. Gene Tucker
Control Systems Laboratory
National Environmental Research Center
Research Triangle Park, North Carolina 27711
Prepared for
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460
May 1974
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This report has been reviewed by the Environmental Protection Agency
and approved for publication. Approval does not signify that the
contents necessarily reflect the views and policies of the Agency,
nor does mention of trade names or commercial products constitute
endorsement or recommendation for use.
11
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TABLE OF CONTENTS
Page
CHAPTER I. ABSTRACT 1-1
CHAPTER II. INTRODUCTION . . . . II-1
CHAPTER III. DESCRIPTION OF THE APPROACH III-l
Steps in Preparation of Industrial
Profile III-l
Selection of Experts III-2
Identification of Emerging Technology. . . III-3
CHAPTER IV. AIR POLLUTION PROBLEMS AND DEMONSTRATION
OPPORTUNITIES IV-1
Secondary Nonferrous Metals Industry . . . IV-1
Burning of Insulation and Other
Organics from Copper Scrap in
Copper Segment . 0 . . IV-1
Removal of Organics such as Cutting
Oils, etc., in Brass and Bronze
Segment IV-1
Sulfur Oxide Emissions from Melting
of Battery Plate Scrap in the
Lead Segment IV-2
Collection and Utilization of Fumes
and Dust from Smelting and Refining
Operations and Disposal of Heavy
Metal Sludges from Wet Scrubbers. . . IV-3
Development of New Processes .... IV-4
Modification of Current Processes . . IV-5
Halide Evolution from Aluminum
. Segment IV-6
Pollution from Aluminum Drosses ... IV-6
Demonstration Opportunities IV-6
111
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TABLE OF CONTENTS
(Continued)
Page
Petroleum Refining Industry TV-7
Catalytic Cracker IV-7
Claus Plant IV-7
Disposal of High-Sulfur Resids. . . . IV-8
Combustion Sources IV-8
Discussion IV-8
CHAPTER V. CONCLUSIONS AND RECOMMENDATIONS V-l
Methodology V-l
Demonstration Opportunities in Secondary
Nonferrous Metals Industry V-2
Demonstration Opportunities in the
Petroleum Refining Industry V-3
APPENDIX A
NOMENCLATURE (EPA-CSL) A-l
LIST OF EXPERTS FOR PETROLEUM REFINING INDUSTRY A-3
LIST OF EXPERTS FOR THE SECONDARY NONFERROUS METALS INDUSTRY . A-3
APPENDIX B
(THE PETROLEUM REFINING INDUSTRIAL PROCESS PROFILE)
INDUSTRY DESCRIPTION B-l
Companies B-5
Size B-5
Location B-5
Future Trends B-7
IV
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TABLE OF CONTENTS
(Continued)
Page
ENVIRONMENTAL IMPACTS B-8
Atmospheric Emissions .... B-8
Liquid Effluents B-9
Solid Wastes B-9
RAW MATERIALS B-9
PRODUCTS B-10
PROCESSES B-14
WASTE CONTROL METHODS B-49
Flares B-49
Wastewater Treatment B-50
REFERENCES B-51
APPENDIX C
(THE SECONDARY NONFERROUS METALS INDUSTRIAL PROCESS PROFILE)
INDUSTRY DESCRIPTION C-l
DISCUSSION OF SECONDARY NONFERROUS METALS INDUSTRIAL
PROCESS PROFILE C-2
Segments C-2
Major Companies C-3
Manufacturing Operations C-3
Processes C-6
Process Steps C-6
Future Trends C-6
ENVIRONMENTAL IMPACTS C-7
Atmospheric Emissions C-7
Emission of Aqueous Wastes C-8
Solid Waste Emissions C-9
RAW MATERIALS C-10
PRODUCTS C-ll
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TABLE OF CONTENTS
(Continued)
PROCESS DESCRIPTION OF ALUMINUM SEGMENT OF SECONDARY
NONFERROUS METALS INDUSTRY C-12
Raw Materials C-12
Products C-13
Process Description C-13
Population of Secondary Aluminum Processors C-27
PROCESS DESCRIPTION OF THE ANTIMONY SEGMENT OF THE
SECONDARY NONFERROUS METALS INDUSTRY C-30
Raw Materials C-30
Products C-31
Process Description C-31
Population of Secondary Antimony Processors ....'.... C-35
PROCESS DESCRIPTION OF THE BERYLLIUM SEGMENT OF THE
SECONDARY NONFERROUS METALS INDUSTRY C-37
Raw Materials C-37
Products C-37
Process Description C-37
Population of Secondary Beryllium Processors C-38
PROCESS DESCRIPTION OF THE BRASS AND BRONZE SEGMENT OF THE
SECONDARY NONFERROUS METALS INDUSTRY C-39
Introduction C-39
Raw Materials C-39
Products C-41
Process Description C-42
Population of Secondary Brass and Bronze Processors .... C-55
PROCESSING DESCRIPTION OF THE CADMIUM SEGMENT OF THE
SECONDARY NONFERROUS METALS INDUSTRY C-58
Raw Materials C-58
Products C-58
Process Description C-59
Population of Secondary Cadmium Processors C-61
PROCESS DESCRIPTION OF THE COBALT SEGMENT OF THE SECONDARY
NONFERROUS METALS INDUSTRY C-63
Raw Materials C-63
Products C-63
Process Description C-64
Population of Secondary Cobalt Processors C-67
PROCESS DESCRIPTION OF THE COPPER SEGMENT OF SECONDARY
NONFERROUS METALS INDUSTRY C-69
Raw Materials C-69
Products C-70
Process Description C-70
Population of Secondary Copper Processors C-94
vi
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TABLE OF CONTENTS
(Continued)
Page
PROCESS DESCRIPTION OF THE GERMANIUM SEGMENT OF THE
SECONDARY NONFERROUS METALS INDUSTRY C-97
Raw Materials C-97
Products C-97
Process Description C-97
Population of Secondary Germanium Processors C-98
PROCESS DESCRIPTION OF THE HAFNIUM SEGMENT OF THE
SECONDARY NONFERROUS METALS INDUSTRY C-100
Population of Secondary Hafnium Processors C-100
PROCESS DESCRIPTION OF THE INDIUM SEGMENT OF THE
SECONDARY NONFERROUS METALS INDUSTRY C-101
Population of Secondary Indium Processors C-101
PROCESS DESCRIPTION OF THE LEAD SEGMENT OF THE
SECONDARY NONFERROUS METALS INDUSTRY C-102
Introduction C-102
Raw Materials C-102
Products C-103
Process Description C-103
Population of Secondary Lead Processors C-114
PROCESS DESCRIPTION OF THE MAGNESIUM SEGMENT OF SECONDARY
NONFERROUS METALS INDUSTRY C-117
Raw Materials . C-117
Products C-117
Process Description C-118
Population of Secondary Magnesium Processors C-120
PROCESS DESCRIPTION OF THE MERCURY SEGMENT OF THE SECONDARY
NONFERROUS METALS INDUSTRY C-122
Raw Materials C-123
Product C-123
Process Description C-124
Population of Secondary Mercury Processors C-128
PROCESS DESCRIPTION OF THE NICKEL SEGMENT OF THE SECONDARY
. NONFERROUS METALS INDUSTRY C-131
Raw Materials C-131
Products C-131
Process Description C-131
Population of Secondary Nickel Processors C-135
vii
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TABLE OF CONTENTS
(Continued)
PROCESS DESCRIPTION OF THE PRECIOUS METALS SEGMENT OF THE
SECONDARY NONFERROUS METALS INDUSTRY C-138
Raw Materials C-L38
Products C-139
Process Description C-139
Population of Secondary Precious Metals Industries C-142
PROCESS DESCRIPTION OF SELENIUM SEGMENT OF SECONDARY
NONFERROUS METALS INDUSTRY C-144
Raw Materials C-144
Products C-144
Process Description C-144
Population of Secondary Selenium Processors C-147
PROCESS DESCRIPTION OF THE TIN SEGMENT OF THE SECONDARY
NONFERROUS METALS INDUSTRY C-150
Raw Materials C-150
Products C-151
Process Description C-151
Population of Secondary Tin Processors C-157
PROCESS DESCRIPTION OF THE TITANIUM SEGMENT OF THE SECONDARY
NONFERROUS METALS INDUSTRY C-160
Raw Materials C-160
Products C-160
Population of Companies C-160
Process Description ... C-161
Population of Secondary Titanium Processors C-163
PROCESS DESCRIPTION OF ZINC SEGMENT OF THE SECONDARY
NONFERROUS METALS INDUSTRY C-165
Introduction C-165
Raw Materials C-165
Products C-166
Process Description C-166
Population of Secondary Zinc Processors C-182
PROCESS DESCRIPTION OF THE ZIRCONIUM SEGMENT OF THE
SECONDARY NONFERROUS METALS INDUSTRY C-185
Population of Secondary Zirconium Processors C-185
viii
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1-1
I. ABSTRACT
Results of a study to develop methodology for characterizing
major industries from the standpoint of their present environmental impact
and assessing the probable effect of emerging process technology on
environmental considerations are discussed. A systematic method for
separating the industries into process modules is described and illustrated.
Applicability of this approach is demonstrated, using the petroleum refining
and secondary nonferrous metals industries as examples. These are two
industries with substantially different characteristics. An approach
utilizing expert opinion for rapid identification of emerging technology
is also reported and a discussion of technology under development in the
two industries is presented.
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II. INTRODUCTION
The objectives of the study were to develop an approach to the
assessment of the environmental effects associated with industrial activities
and identification of new process technology which could be employed to
minimize adverse environmental effects. The approaches developed were
intended to be suitable for rapid assessment of major industries so that
EPA could assess the future need for demonstration programs similar to
those used to promote the use of newly developed technology to the electric
utilities and by the iron and steel industry.
The petroleum refining industry and secondary nonferrous metals
industry were selected for evaluation in a pilot program. The differences
in the character of these two industries would help identify all pertinent
factors in a methodology which would be applicable, with little or no
modification, to any industry or interest.
Phase I of the study was concerned with development of industrial
process profiles for each industry. The profiles are included as Appendix B
(Refining) and Appendix C (Nonferrous Metals). The companies of importance,
the raw materials used, processes employed, and the products and wastes
were identified. Standard terminology under development by EPA's Control
Systems Laboratory for similar studies was employed, and is included as
Appendix A. The industry profiles were developed from information obtained
from the literature available within Battelle and by telephone contacts
with industries. After assembling readily available information, a list of
practicing industry experts was developed for Phase II.
Phase II of the study consisted of consulting with the experts
from the two industries to verify the accuracy and completeness of the
profiles and to identify technological trends and developments germane
to the project. The input by the experts to the profiles and to the
identification of environmental problem areas that have received recent
technological solutions was considerable.
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II-2
In Phase III information on emerging technology* was assessed
and candidate demonstration projects were identified. Projects were
considered primarily from the standpoint of their potential for achieving
a significant reduction in air pollution. The feasibility of setting up
a jointly-sponsored government-industry project was also examined.
In Phase IV experience gathered during the course of the study
was reviewed by participating staff as the basis for preparation of this
report. Here the experience in applying the identification approach to
the petroleum refining and the secondary non-ferrous metals industries
were assessed.
It is anticipated that the information developed in this study
coupled with EPA's broad knowledge of air pollution control needs can be
used to select candidate demonstration projects. Pursuing selected can-
didate projects to obtain defined end results could be done by the EPA
either alone or in concert with a contractor mutually acceptable to both
the EPA and the candidate company. It is also anticipated that the
techniques developed here will assist in similar assessment work of other
industries.
* The term "emerging technology" connotes technology in a developmental
state that has a good potential for commercialization and significantly
helps to abate existing environmental problems in the industry. The
technology may include a new process, a process modification, or an
improved emission control technique or a combination of these.
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III-l
III. DESCRIPTION OF THE APPROACH
The approach to identification of the emerging technology* was
comprised of the various tasks indicated in Figure III-l completed in four
phases and in four time frames. As indicated in Figure III-l, some of the
tasks in each of the phases are accomplished concurrently. The tasks in
each phase are defined as follows.
Phase I. (1) Gather available in-house process data
(2) Obtain available process data from industry by
telephone contacts. Also concurrently
establish industry contacts
(3) Incorporate the above data along with prior
in-house experience into generation of industry
process profiles (See Appendix C)
Phase II. (4) Concurrent with Tasks (1) and (2) of Phase I
conduct preliminary selection of experts from
industry and private consultation firms
(5) Coincident with the completion of Task (3) of
Phase I, select final list of experts
(6) Have the industry process profiles reviewed by
the experts of the industry
Phase III. (7) Finalize the industry process profiles after
incorporating additions, changes and other
comments from the experts
(8) With expert opinion, complete the precise
definition of environmental problems
(9) List and elaborate on the identified emerging
technology* in each industry
Phase IV. (10) Prepare final report of the results of the
approach. Make appropriate recommendations.
* See definition on Page II-2 (footnote).
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PHASE I
PHASE II
PHASE III
PHASE IV
TIME
FRAME 1
Gather Data
In-House
(major Input)
Gather Data
from Industry
(minor input)
TIME
FRAME 2
Preliminary Selection
of Experts
(from industry and
private consultants)
Prepare Industrial Process
Profiles. Do Preliminary
Identification of Environ-
mental Problems & Solutions
TIME
FRAME 3
Final
Selection
of Experts
Review
by
Experts
Prepare Final
Process
Profiles
Precise
Definition of
Environmental
Problems
List
Identified
Emerging
Technology*
TIME
FRAME
H
ro
Prepare Final
Report with
Recom-
mendations
FIGURE III-l. SCHEMATIC OF APPROACH TO IDENTIFICATION OF EMERGING TECHNOLOGY*
* The term "emerging technology" connotea technology in a developmental state that has a good potential for
commercialization and significantly helps to abate existing environmental problems in the industry. The
technology may include a new process, a process modification, or an improved emission control technique or
a combination of these.
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III-3
The approach described above while enabling an orderly perform-
ance of the tasks also permits planned contact with the most knowledgeable
persons in the area under study.
Steps in Preparation of Industrial Process Profile
The secondary nonferrous metals industry is highly fragmented
from the standpoint of processes employed, has a multiplicity of products,
utilizes numerous raw materials and produces a wide variety of potential
air pollutants. In all, the industry encompasses some 20 different
segments, (comprising a total of 135 processes) each of which is unique in
regard to raw materials sources, products produced, processes employed and
pollution potential. Therefore, each segment had to be treated separately.
The pe.troleum refining industry, more standardized from the standpoint
of technology employed, was reducable to 29 processes.
In developing the industrial process profile for secondary non-
ferrous smelting, the first task entailed the development of industry
segment profiles. This involved initially, the use of the literature and
Battelle personnel to develop flowsheets and process descriptions. Each
flowsheet identified:
(1) The manufacturing operations
(2) The processes within each operation
(3) The processing steps within each process
(4) Raw materials, source of energy, etc., used
in each process
(5) Types of potential pollutants—atmospheric
emissions, aqueous waste, and solid waste
(6) Intermediate products and final products.
The flowsheets were then used as guides around which to build the process
descriptions. A similar- approach was used for petroleum refining.
In addition to discussing the above items, composition of
emissions, seriousness of the atmospheric pollution problems, and disposal
of the waste materials were taken into consideration and the pollution
potential of the present processes were defined. For this task standard
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III-4
nomenclature and techniques developed by the Control Systems Laboratory for
industry analysis were used. The nomenclature definitions are shown in
Appendix A. Having completed this task, the next task involved the
identification of emerging technology and obtaining expert opinion on
validity of the flowsheets and process descriptions.
Selection of Experts*
Because of the complexity of the secondary nonferrous metals
industry, the selection of two or three experts to cover the entire
industry was not possible. Instead, it was necessary to select experts
in the specific segments of the industry. Initial selection of experts
was made based on recommendations from management officials in the major
companies.- The experts suggested were then interviewed by telephone
and, if found technically qualified for the task, were enlisted to provide
assistance on this project.
The petroleum refining industry, being more systematized, re-
quired discussion with fewer experts.** Those used were selected to pro-
vide a cross section of opinion; i.e., one was employed by a major petroleum
company, two were employed by a major engineering company, one was a private
consultant and one was a Battelle in-house expert.
Identification of Emerging Technology***
First, a preliminary initial identification of emerging tech-
nology was done by the use of current literature and Battelle's in-house
expertise. Next, experts in the two industries of interest and government
agencies such as the U. S. Bureau of Mines were contacted by telephone
and/or personal visits to:
(1) Identify additional emerging technology
* See Appendix A (Page A-4) for list of experts contacted.
** See Appendix A (Page A-3) for list of experts contacted.
*** See definition on Page II-2.
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III-5
(2) Obtain their opinion on the previously
identified emerging technology
(3) Obtain comments on the accuracy and thoroughness
. of the process descriptions and flowsheets of
the various segments and make corrections
where necessary.
In arranging visits, the normal procedure was to contact a
company by telephone at least 3 weeks prior to any visit to request
assistance on the subject. If agreeable, as was the case in most instances,
a package including a process flowsheet, process description, and brief
write-ups on emerging technology was mailed at least one or two weeks
prior to the visit. Many companies requested time to allow several
individuals to review the data.
During the visit (which was made generally by two BCL personnel),
the process descriptions and flowsheets were reviewed first, followed by
review of the emerging technology that BCL staff had identified. Then
efforts were made to identify additional emerging technology in terms of
air pollution control approaches, future trends in processing, and also
obtain atmospheric emissions data. Information on candidate companies
who would be interested in jointly funded demonstration studies was sought.
Also, efforts were made to determine the attitude of the company
toward such matters as demonstrations with government support, type of
support most beneficial to the secondary industry, and technical capabilities
of the company. The results of the efforts are described in appropriate
Sections on pages V-2, V-3, C-l and C-2.
Simultaneously, the same packages were being reviewed by outside
consultants and the same questions were being posed to them. Conferences
also were being held with consultants at BCL as well as in the field.
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IV-1
IV. AIR POLLUTION PROBLEMS AND DEMONSTRATION OPPORTUNITIES
Secondary Nonferrous Metals Industry
The secondary nonferrous metals industry presents a wide variety
of air pollution problems associated mostly with pyrometallurgical processes
used for smelting, refining, and burn-off of foreign materials. Some of the
most important problems and specific solutions of interest are discussed
below.
Burning of Insulation .and Other Organics
from Copper Scrap in the Copper Segment
Problems encountered are: (a) toxicity and corrosive nature of
the gases due to the halogen, sulfur, and heavy metals content, (b) high
concentration-of unburned organic materials, and (c) the loss of metal
values contained in the atmospheric emissions. Efforts to control these
emissions have had limited success. New or improved technology is needed.
Specific solutions toward controlling atmospheric emissions being
tried are :
(1) The U. S. Metals Refining Company of Carteret, New Jersey, is
using a reactant-coated baghouse to collect HC1 and other halides
which are liberated when copper wire is burned to remove insu-
lation.
(2) The Apex Smelting Company of Chicago, Illinois, is installing a
chemically coated baghouse at its aluminum smelter in Cleveland,
Ohio, to collect chlorides from the demagging operation.
Removal of Organics. Such as Cutting Oils,
from Scrap Turnings, Shavings, and Borings,
as in the Brass and Bronze Segment
Problems encountered are: (a) high incidence of fires in the bag-
houses, (b) heavy emissions of zinc oxide and other metallic fumes, and
(c) severe fire hazard during the charging of the scrap to the melting pot.
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IV-2
These problems are encountered in the Brass and Bronze Segment
and the Copper and Aluminum Segments.
One specific solution to the problem of fire in baghouses in
current use is described below.
The ABC* Company of XYZ* City is injecting a fine powder into
the off gases from the brass and bronze melting furnaces. This fine powder
reduces the incidence of fires in the baghouses, apparently by reaction
with the fumes, dusts, and/or gases to form products which do not ignite as
readily as the original material. Other companies are de-oiling the scrap
before melt-down by burning to reduce chances of fire. The ABC Company
claims that de-oiling is not necessary.
Sulfur Oxide Emissions from Melting of
Battery Plate Scrap in the Lead Segment
Battery plate scrap is contaminated with residual sulfuric acid.
Failure to remove the acid prior to melting results in evolution of sulfur
oxides. The SO emissions vary, being high during initial melt-down and
A
low at the end of the processing stage.
This is a major problem in the Lead Segment; the Copper Segment
faces similar problems.
Solutions being tried for the abatement of SO emission from Lead
X
Segment are:
(1) Lime-sulfur dioxide scrubbing system at the General Battery Corporation,
Reading, Pennsylvania. This system uses wet scrubbing with hydrated
lime. The underflow sludge, the flyash resulting from burning pulverized
coal and the crushed plastic battery cases are being tried to produce a
composition that is sanitary, nonreverting, nonleaching and dimensionally
stable.
The process was developed by G & W.H. Corson Inc., Plymouth Meeting,
Pennsylvania. The Company is not desirous of EPA assistance in the
project.
*
Names and identity are deliberately withheld, as requested.
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IV-3
(2) The U. S. Bureau of Mines in College Park, Maryland, is developing a
process for reducing the sulfur oxide emissions from recovery of lead
from scrap battery plates. This process entails:
(a) Heating a mixture of the lead scrap and calcium
hydroxide in a calciner to convert the sulfur
content to calcium sulfate
(b) Adding solid reducing agent and flux and reducing
the charge at 650°C which is below the decomposition
temperature of calcium sulfate
(c) Removing molten lead for further processing and the
slag for disposal. Consideration is being devoted
to developing a process for the regeneration of the
calcium sulfate to lime for recycle and generation of
elemental sulfur for use in other processes.
Collection and Utilization of Fumes and
Dusts from Smelting and Refining Operations
and Disposal of Heavy Metal Sludges from Wet Scrubbers
Problems encountered are: (a) collection of fine dust particles
(less than 0.5 micron in diameter), (b) loss of valuable metals, (c) high
level emissions to the atmosphere from current pyrometallurgical processes,
and (d) disposal of dusts and fumes collected in baghouse in landfills
which could result in severe water pollution problems and possibly air
pollution problems.
Wet scrubber sludges resulting from control of atmospheric emissions
contain metal values too dilute to render its recovery economical. Again,
these sludges are disposed off in landfills, thus making water pollution
problems a possibility.
The melt-down of scrap fines together with coarse scrap in many
segments results in heavy evolution of metallic dusts and fumes. To avoid
this problem, some companies dispose of the scrap fines in landfills rather
than recover the metal value in it. The result could be a water pollution
problem from the leachates.
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IV-4
The above problems are being solved by the industry by multiple
approaches. Examples are provided below.
Development of New Processes. (1) Hydrometallurgical systems
are being examined as a means of reducing atmospheric emissions by
eliminating the pyrometallurgical step in the recovery process. For example,
Electrolytic Zinc Company of Australia, Limited, has developed a new hydro-
metallurgical process for extracting lead from zinc plant residues using
aqueous solutions containing ammonia and ammonium sulfate to dissolve lead
compounds insoluble in conventional solvents. The Bureau of Mines, Salt
Lake City Metallurgy Research Center, Salt Lake City, Utah, has developed
a process for the recovery of copper for all grades of scrap copper using
an ammonium carbonate system. Essentially, no atmospheric emissions are
generated and aqueous solutions can be regenerated and recycled. The copper
can be recovered as the powder, oxide, or as cathodic copper.
(2) U. S. Metals Refining Company (Division of AMAX) at
Carteret, New Jersey, is developing a hydrometallurgical process for the
recovery of metal values from dust and fumes collected as baghouse dusts from
the various segments of the primary and secondary industries. The process
has been developed through the laboratory stage and is now ready for pilot-
plant development.
Basically, the process entails the extraction of metal values
from the baghouse dusts with an aqueous leachant to produce a metal-laden
liquor. The metal values, such as zinc, are then recovered from this liquor
by an electrolytic process. In those instances where the dusts contain
high concentrations of iron values, the leach residue after removal of the
nonferrous metal values is returned to the steel industry for processing
in the blast furnaces. Other metals such as lead and tin are recovered at
various stages in the process.
While this process does not treat the air pollution problem from
the secondary nonferrous metals industry per se, it does eliminate or
reduce a potentially serious water pollution problem which could arise upon
disposal of the dusts and sludges by landfilling. Furthermore, the process
recovers valuable metals which would not otherwise be recovered.
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IV-5
(3) Zinc dust manufacture is rapidly growing in the Zinc Segment.
One new process which has been introduced into this country is a Norwegian
process known as the Larvic process. In this process, the zinc is vaporized
using graphite rod resistors above the melt contained in a reverberatory
furnace. Consequently, emissions are minimized as there are no combustion
gases. Currently, the process is being used by The American Smelting and
Refining Company, in New Jersey. This process is in contrast to the pyro-
metallurgical processes for zinc powder manufacture used in the U. S.
Although theoretically hydrometallurgical processes can be used for making
zinc powder, there is no evidence of its use in the U. S.
(4) Battelle's Columbus Laboratories, Columbus, Ohio, is
developing a process for fluxless melting of magnesium. The process is
designed to use small percentages of hexafluoride in air as a protective
atmosphere for molten magnesium in various molten metal handling operations.
Successful development of this process will: eliminate or minimize the use
of flux when melting magnesium; result in reduced air pollution problems
associated with the flux; reduce the solid wastes generated; and produce
cleaner castings. Currently, the process is in the laboratory stage of
development.
Modification of Current Processes. Oxygen-enriched air or in
some cases pure oxygen is being used in a number of industry segments,
e.g., Copper, Lead, and Aluminum. Advantages are reduced volume of
off-gases, increased production capacity, and low emission of dusts and
fumes per ton of metal produced. Two companies currently using oxygen
or enriched air are Franklin Smelting Company of Philadelphia, Pennsylvania,
and Chemical Metals Corporation, East Alton, Illinois. Franklin Smelting
Company has developed a rotary converter for the production of black
copper. Emissions should be significantly reduced over conventional con-
verters as surface lancing in place of tuyerers is used and pure oxygen
is used in place of air. Chemical Metals Corporation is using enriched
air overhead converters.
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IV-6
Hallde Evolution from Aluminum Segment
Demagging of aluminum with gaseous chlorine results in the
evolution of large quantities of chlorine, primarily as aluminum chloride.
The use of solid demagging agents such as aluminum fluoride or aluminum
chloride instead of chlorine reduces the degree of severity of the problem
and is being practiced by the industry. A new approach involves the use of
a precoated baghouse (chromatographic baghouse) which removes both the
halides and particulate matter. This technique is being tested on a
commercial in Canada, and several U. S. Companies are contemplating building
commercial-size units.
Pollution from Aluminum Drosses
Drosses from the Aluminum Segment consist of aluminum, sodium,
and potassium chlorides, fluxes, etc. These react with atmospheric nitrogen
and water to form ammonia, an atmospheric pollutant. The quantity of drosses
is significant and solution to the problem is not attempted in the U. S. yet.
It appears that the European industry has a process to recover
the aluminum from the drosses and recycle the salts and fluxes. The specific
details of this technology are not known at this time.
Demonstration Opportunities
Any of the solutions described above can be a potential candidate
for a demonstration project. However, exact definition of the solution
being tried and the willingness of the developers to cooperate in a demon-
stration project with EPA needs detailed investigations. As noted above,
many of the developers are unwilling to invite the EPA.
Some of the companies might welcome cooperation and support by
EPA through a mutually acceptable contractor or coordinator. The secondary
nonferrous metals industry is primarily production oriented and the suspicion
that EPA intervention might hinder their normal production activities appears
to .-have put the industry on guard.
Further work in this direction to more clearly identify demon-
stration projects and companies willing to cooperate is worthwhile.
-------
IV-7
Petroleum Rafi.ni.ng Industry
Petroleum refineries have four air pollution related problems:
(1) particulate and SO emissions from the Cat-Cracker Catalyst Regenerator,
(2) emission of sulfur oxides in tail gases from Glaus plants, (3) emissions
from fuel combustion in the industry and (4) Disposal of high-sulfur residue
fuels.
Catalytic Cracker
Catalytic cracker regenerator flue gases contain particulates and
at times significant quantities of sulfur oxides. Electrostatic precipitators
are most commonly employed to remove particulates; sulfur oxides are not
normally controlled. Exxon plans to install a full-scale (size) scrubber
that employs a soda ash solution for removal of both pollutants. The unit
is expecfed to produce data needed for design of future units. Evaluation
of the effectiveness of this unit may be useful if sulfur oxides from cat
cracking will require more effective control in the future.
Glaus Plf->f.
A number of processes designed specifically for Glaus plants are
being introduced for inore effective control of sulfur emissions in the tail
gas. These include Shell's Scot process, Union Oil's Beavon process, the
Cleanair process offered by J. F. Pritchard, the IFP process developed by
Institut Francais du Petrole, Lurgi's Sulfreen process and the Takahax
process licensed by Kellogg. In addition, the Wellman-Lord process and
the citrate process are being offered for tail gas scrubbing. A demonstra-
tion or evaluation of one or all of these processes would be appropriate
if EPA considers the development of data on the economics of control use-
ful. Such information would be useful in defining the control alternatives
open to refineries as they replace dwindling supplies of sweet crude with
available high-sulfur crude.
-------
IV-8
Disposal of High Sulfur Resids
Refining capacity in the U. S. is being expanded and more high-
sulfur crudes are being refined. Therefore, supplies of high-sulfur resid
will increase and processes for its utilization in economical environ-
mentally sound ways will be increasingly useful. A process that could be
used to convert resid into a nonpolluting fuel would be especially
attractive. Two possible processes for such service are the Chemically
Active Fluid Bed and Exxon's Flexicoking. Both gasify the coked resid.
Combustion Sources
Major refineries contain furnaces in processes such as crude
distillation that are as large as a furnace in a 100-MW power plant.
Demonstration of a flue-gas cleaning system for such furnaces may be use-
ful in defining possibilities for control of such systems and may adapt the
furnaces for use of high-sulfur fuel. One of the by-product flue-gas
cleaning processes may be especially appropriate since most refineries are
already in the sulfur recovery business.
Discussion
The usefulness of any of the demonstrations will depend in part
on EPA's planned approach to refinery control. It is doubtful that any of
the processes identified present serious technical problems that most
refiners could not solve for themselves. Hence the situation is not
analogous to that in the utilities industry where help is needed in the
solution of the technical problems. Justification for undertaking demon-
strations probably is related to economic clarification or to support base
standards, rather than to solution of technical problems.
There is some evidence to suggest that some companies (especially
the largest ones) in the industry will not readily welcome EPA cooperation
in what is considered the industry's area of responsibility. However,
-------
IV-9
probably not all refiners share this sentiment. One consultant suggested
that the moderate-sized refiners would welcome assistance and suggested
contact with Petrofina, Ashland and Pasco. The smaller refiners would
not have the economic or technical capability or physical facilities
necessary to cooperate in a demonstration program.
-------
V-l
V. CONCLUSIONS AND RECOMMENDATIONS
Methodology
The principal conclusions relating to methodology are as follows;
(1) The methods developed for use in generating
industry profiles and identification of the
processes which comprise the industry appear,
on the basis of their application to two
dissimilar industries, to be generally applicable
for systematic study of any industry.
(2) Expert opinion can be used to develop the
perspective needed to understand environmental
effects of a given industry if a proper approach
is used. Consideration should be given to
selection of experts who are affiliated directly
with the industry and others who are knowledgable
but not employed directly by companies in the
industry. This appears to help insure that problems
are kept in proper perspective.
(3) Also, it appears that at least three experts should
be consulted. Where fewer are used there seems to
be a good chance that experience gaps can lead to
development of an inaccurate concept of some
controversial issues.
(4) Also, it would appear that at least one paid consultant
be used where review of industry profiles are concerned.
Few of the experts employed by industry who cooperated
without compensation found time for a detailed review of
the draft version of the industry profiles that had been
supplied for criticism.
(5) Finally, it was evident that careful preparation prior
to contact with experts was necessary to assure that
maximum benefit was obtained. Preparation of the best
possible industry profile and complete list of potential
-------
V-2
new processes would help to bring in outside help
and inputs.
(6) If future studies are undertaken, a document
describing EPA's policies and procedures for
demonstration' studies should be made available to
industry representatives who are to be contacted.
Such a document would have been helpful in elim-
inating the suspicions and reservations relating
to loss of proprietary rights and trade secrets,
etc.
Demonstration Opportunities in Secondary
Non-Ferrous Smelting Industry
The principal conclusions relating to demonstration opportunities
in the secondary non-ferrous smelting industry are as follows:
(1) The secondary non-ferrous metals industry is in need of
assistance in reducing or eliminating atmospheric emissions
from the numerous processes involved throughout the entire
industry. However, the majority of the companies
that make up the secondary non-ferrous metal industry are
medium-sized privately-owned companies and are not generally
equipped to deal with the development and application of new
technology for control of pollution. They lack the technical
capability and financial resources which are needed.
(2) There is an indication that some work toward pollution abate-
ment in the secondary nonferrous metals industry is underway and
its application might be accelerated if demonstrations were
given partial support. Such support might also encourage
the industry to undertake additional work. From this stand-
point, projects in this industry should enjoy high priority.
(3) The Environmental Protection Agency has developed an image
in some instances as being a "police" force. Consequently,
companies are reluctant to enter into agreements with the
-------
V-3
Federal Government which would give the representatives
of EPA access to company data. However, some companies
would welcome assistance in this area.
(4) Industry is concerned that any venture with the Federal
Government may result in loss of patent rights to the process.
The secondary nonferrous industry is very competitive and each
company guards its secrets very closely. If companies can
be assured that rights will be guarded, they may be willing
to enter into jointly-funded ventures.
(5) Although companies in the industry produce different pro-
ducts, many of the pollutants are similar and in many cases,
the same. Thus, pollution problems are common to several
segments of this ir.duptry. For example, sulfur oxide
emission is a common pollutant to the copper and lead
segments of both the secondary and primary nonferrous metals
industries while the manufacturing operations are different.
It was the opinion of officials from several companies that
emphasis in pollution abatement should be directed wherever
possible toward the development of add-on pollution control
equipment rather than process modification. Such equipment
could then be used by several segments of industry and, thus,
many could benefit rather than a few. Also development of
add-on equipment could be conducted without disclosure of
company secrets.
Demonstration Opportunities in the
Petroleum Refining Industry
The principal conclusions relative to demonstration opportunities
in the petroleum refining industry are as follows:
(1) In general the industry understands its problems and has
available to them the technology needed to solve their
own problems. Further they are financially in a better
position to support the work necessary to bring their
problems under control than many other industries.
-------
V-4
(2) The companies refining petroleum vary widely in size.
The large companies neither need or would
welcome government support for projects. The small
companies we«W generally lack financial capability
and technical support to participate in such studies.
The medium size companies would appear to be the most
likely to have the capability and motivation to par-
ticipate in jointly funded work.
-------
A-l
APPENDIX A
NOMENCLATURE
LIST OF EXPERTS FOR PETROLEUM REFINING INDUSTRY
LIST OF EXPERTS FOR SECONDARY NONFERROUS METALS
" INDUSTRY""
NOMENCLATURE
1. RAW MATERIALS are feed materials for processes. They- are of two types:
primary raw materials that are used in. the chemical form that they were
taken from the land, water or air and secondary raw materials that are
industrial intermediate products.
2. INDUSTRIES are made up of groups of companies that are considered
competitors in production of 'che same products. Industries have an
identifiable population of companies and have a high degree of commonality
with respect to raw materials consumed, processes employed, products
produced, environmental control problems experienced, pollutants produced
.and control equipment used,
3. OPERATIONS are general industrial procedures by which materials are
processed or products produced. Operations can consist of a series of
processes, or can be accomplished by two or more alternative processes.
4. PROCESSES are the basic units that collectively describe industries.
Processes comprise specific arrangements of equipment that accomplish, in
a distinct way, chemical or physical transformation of input materials
into end products, intermediate products, secondary raw materials or
Waste materials. Other process outputs include waste streams to the air,
water, or land. Input materials can include primary or" secondary rav/
materials, waste materials, or intermediate products. Where two or more
different combinations of process steps accomplish the same chemical or
physical transformation but have different environmental impacts (e.g.,
different emission characteristics), each combination is a distinct process.
-------
A-2
5. PROCESS STEPS are the basic components of a process that utilize process
equipment or materials handling equipment (process equipment does not
include control equipment). In cases where a piece of process equipment
has two. or more cycles or phases of operation with distinctly different
emissions to the atmosphere, such cycles or phases can be considered
sequential process steps.
,.•'
6. SOURCES are process steps from which significant amounts of air, water,
or land pollution can be discharged.
7. CONTROL EQUIPMENT is equipment whose primary function is to reduce emissions
to the atmosphere. Its presence is not essential to the economic viability
of the process.
8. COMPANIES include corporate sub-divisions that have a product slate similar
to other companies in an industry.
9. PLANTS are comprised of collections of processes to produce the products
associated with their industry. Individual plants within an industry may
employ different combinations of processes but all plants will have
some of the processes that are common to the industry.
10. END PRODUCTS include only those process outputs that are marketed for use or
consumption in the form that they exit from the process. After use, an end
product becomes a waste material.
11 • INTERMEDIATE PRODUCTS are process output streams that go either to other
processes in the same industry in which they are produced, or to other
industries where they become secondary raw materials..
12• WASTE MATERIALS are either process outputs that go to a scavenging industry,
or are used end products that are disposed or processed to recover reusable
constituents.' •
-------
A-3
LIST OF EXPERTS FOR PETROLEUM REFINING INDUSTRY
Mr. W. L. Lewis
Mr. H. H. Meredith
The Exxon Company
P. 0. Box 2180
Houston, Texas
Mr. E. Lewis Whittington
Mr. A. G. Sliger
Dr. W. F. Hoot
M. W. Kellogg Company
1300 Three Greenway Plaza East
Houston, Texas 77046
Mr. Lee H. Solomon
Turner, Mason, and Solomon
1950 Mercantile Dallas Building
Dallas, Texas 75201
Mr. David Moore
Battelle-Columbus Laboratories
505 King Avenue
Columbus, Ohio 43201
Mr. Paul W. Spaite
Consulting Engineer
6315 Grand Vista Avenue
Cincinnati, Ohio 45213
Telephone (513) 731-3991
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A-4
LIST OF EXPERTS FOR SECONDARY NONFERROUS
METALS INDUSTRY
Name and Address Area of Expertise
1. Albert L. Belcher, Lead
Bob Merritt
National Lead Company
Hightstown, New Jersey
2. John A. Bitler
Manager, Manufacturing
General Battery Corp.
Reading, Pennsylvania
3. Dr. H. B. Bomberger Titanium
Director, Metallurgy Research Center
RMI Company
Niles, Ohio
Telephone (216) 652-9951
4. J. P. Brull, President, Titanium
Earth Smelting & Refining Co.
Newark, New Jersey
5. H. S. Caldwell, Jr. General
U.S. Bureau of Mines
College Park, Maryland
Telephone (301) 344-4027
6. V. A. Cammarota Mercury
Mercury Specialist
Division of Nonferrous Metals
U.S. Bureau of Mines
4015 Wilson Blvd.
Arlington, Virginia 22303
7. Cobalt Information Center Cobalt
Battelle Memorial Institute
Columbus, Ohio 43201
8. Mr. Denton
Dept. of Commerce
Washington, D. C.
9. Ray Familar Cadmium
Manager of Engineering
Cook County Air Pollution Dept.
Chicago, Illinois
-------
A-5
Name and Address Area of Expertise
10, Dr. Ro Foos
Brush Beryllium Company Beryllium
Cleveland, Ohio
11. E. Godsey Aluminum
American Smelting and Refining Company
Salt Lake City, Utah
12. Bruce G. Gonser General
Consultant
Battelle Memorial Institute
Columbus, Ohio 43201
13. Keith Harris Tin
Division of Nonferrous Metals
U.S. Bureau of Mines
4015 Wilson Blvd.
Arlington, Virginia 22303
14. Crawford Hayes Brass and Bronze
Chief Project Engineer
Bridgeport Brass Company
Bridgeport, Connecticut 06602
Telephone 366-6182
15. Robert Henning, President Cadmium
Belmont Smelting Company
330 Belmont Avenue
Brooklyn, New York 11207
16. Dr. Kapplain General
U.S. Bureau of Mines
Washington, D. C.
17. B. Langston Aluminum
U.S. Reduction Company
East Chicago, Illinois
18. Dr. Thomas Leontis Magnesium
Magnesium Research Center
Battelle Memorial Institute
Columbus, Ohio 43201
19. Dr. K. Libsch Lead
National Lead Company
Hightstown, New Jersey
20. Earl R. Marble, Jr. Aluminum, Brass &
Consulting Engineer Bronze, Copper
P.O. Box 816, Brainy Boro Station Lead, Tin, Zinc
Metuchen, New Jersey 08840
Telephone (201) 548-4990
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A-6
Name and Addregg Area of Expertise
21. Drew Meyer Tin
Vulcan Material Company
Box 720
Sandusky, Ohio 44870
Telephone (419) 626-4610
22. R. L. John Minnick
Vice President, R&D
Plymouth Meeting, Pennsylvania
23. Stanton Moss Aluminum, Brass, Bronze
Manager, George Sail Metal Company
2255 East Butler Street
Philadelphia, Pennsylvania 19137
Telephone (215) 743-3900
24. Howard Ness
National Association of Secondary Metal Industries
New York, New York
Telephone (212) 867-5000
25. H. R. Ogden Magnesium
Magnesium Research Center
Battelle Memorial Institute
Columbus, Ohio 43201
26. Dr. W. R. Opie, Vice President General
M. Houser, Plant Manager
Amax Company
Carteret, New Jersey
27. Allan Payne Precious Metals
United Refining and Smelting Company
3700 N. Runge Avenue
Franklin Park, Illinois
Telephone (312) 455-8800
28. Milo Peterson
Chairman of Committee, SIC
Office of Management and Budget
Washington, D. C.
29. Dr. Carl Rampacek General
UcS. Bureau of Mines
Washington, D. C.
30... R. W. Roe (and J. Henderson, Sup't of Research) General
Director of Research
ASARCO
South Plainfield, New Jersey
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A-7
Name and Address Area of Expertise
31. William Shirley Aluminum
Apex Smelting Company
Des Plaines, Illinois
32. Paul W. Spaite General
Consulting Engineer
6315 Grand Vista Avenue
Cincinnati, Ohio
Telephone (513) 731-3991
33. Albert W. Spitz & Associates Lead, Tin, Precious
Consultants Metals, Cadmium
Wyncote, Pennsylvania
Telephone (215) 884-7182
34. S. F. Tauben
Diversified Metals
Hazelwood, Missouri
35. Tin Research Institute Tin
483 West 6th Street
Columbus, Ohio 43201
Telephone (614) 294-3341
36. R. R. Wells Nickel
Director, Abany Metallurgy Research Center
Abany, Oregon
Telephone (503) 926-5811, Extension 220
37. Battelle-Columbus Personnel
Marty Forkas
H. Barr
R. Bengston
Columbus, Ohio 43201
-------
B-l
APPENDIX B
THE PETROLEUM REFINING INDUSTRIAL PROCESS PROFILE
INDUSTRY DESCRIPTION
The petroleum refining industry processes crude oil into a large
number of products including liquefied petroleum gas, gasoline, kerosine,
aviation fuel, diesel fuel, a variety of fuel oils, and lubricating oils.
Some of the processes involved in the manufacture of these products are:
distillation, absorption, extraction, thermal and catalytic cracking,
isomerization, hydrogenation, dehydrogenation, polymerization, etc.
Each refinery is more or less unique in that each operation is
carried out using equipment designed to meet needs peculiar to a particular
location. It is possible, however, for purposes of analysis to consider all
refineries as consisting of some combination of the 29 process modules
shown in Table B-l. Figure B-l is a flow diagram showing the interrelationships
between these processes.
Only a few refineries employ all the processes shown in Figure B-l
because some of the processes are (1) proprietary, (2) representative of a
limited size range of refineries, (3) typical of a limited time period, and
(4) designed for a particular crude oil. In addition to the processes shown,
several hundred other process variations are used at a few refineries. Most
of these processes are minor variations of the processes shown in Figure B-l.
Larger refineries generally use most of the processes shown. American
refineries typically use more processes than foreign refineries because they
are designed to produce a maximum amount of motor fuel. European refineries
are designed to produce a higher percentage of heating fuels. The complex
American refineries produce a minimum of residual oil. Less complex
Caribbean refineries with minimum cracking facilities to supply local needs
for motor fuels are major suppliers of fuel oil for the U. S. East Coast.
-------
B-2
TABLE B-l. LIST OF PETROLEUM REFINERY PROCESSES
(1)
Enrryy Required
Process
(1) Crude Storage
(2) Desalting
(3) Crude Distillation
(4)| Vacuum Distilla-
tion
(5) Chemical
Sweetening
(6) Hydrogen
Generation
(7) Naphtha Hydrogen
Treating
(8) Kerosene Hydrogen
Treating
(9) Gas Oil Hydrogen
Treating
(10) Lubricating Oil
Hydrogen Treating
(11) Residual Oil
Hydrogen Treating
(12) Catalytic
Hydrocracking
(13) Gas Processing
(14) Amlne Stripping
(15) Sulfur
Manufacture
US Capacity
Process fM bbl/SD
Type Jan. . 1972 Feed
Open A Crude
Closed a Crude
Closed 13.7 Crude
Closed 4.9 Topped Crude
Closed b Sour Distillate
Closed b Hydrocarbon
Closed 2.8 Gasoline
Closed 1.0 Sour Kerosene
Closed 4.9° Gas Oil
Closed 4.9C Sour Lube Oil
Closed 0 High-Sulfur
Residual
Closed 0.84 Gas Oil
Residuals
Closed 1.3 Mixed Cases
Closed a Hydrocarbon
H2S-Strcam
Open 1.2e HjS
Products
Crude
Dry Crude
.Refinery Gas
. Natural Gasoline
Kerosene
Distillate Fuel
Gas Oil
Topped Crude
Gas Oils
Vacuum Residual
Sweet
Distillate
Hydrogen
Gum- Free and
Sulfur-Free
Gasoline
Desu If urizcd
Kerosene
HjS
Desulfurlzed
Gas Oil
H2S
Desulfurized
Lube Oil
Low-Sulfur
Residual
H2S
Refinery Gas
Gasoline
Diesel Oil
Furnace Oil
Fuel Gas
PC
Butanes
Light Gasoline
Oleflnes
Sulfur-Free
Hydrocarbons
Sulfur
Elcctr irol-
Mechnnlcnl, Steam,
Effluents kwhr/bbl Ib/bbl
.Water b b
Salt 0.01 22
Water
Water 0.1-0.6 15
Oil
Water 0.1-0.3 8
Vent gas
Spent 0.01 b
Chemicals
Carbon b b
Dioxide
Spent 1.4 30-90
Catalyst
Spent 0.5-2 8
Catalyst
Spent 2 1-10
Catalyst
Spent 2.5-9 15-28
Catalyst
Spent 1-4 3-25
Catalyst
Spent Catalyst 1-6 (6)-18
Gas from .
Regeneration
2 0
d
Waste Amlne 0.5 (It
Tall-Cns 0.1 (4)d
Flred-
llcaters,
MBtu/bbl
b
0
100
50
b
0-300
0-50
0-70
5-70
35-140
60-100
100-250
0
0
0.4f
(1) Sec Hat of references at end of re
port.
-------
B-3
TABLE B-l (Continued)
(16)
(U)
(18)
(19)
(20)
(21)
(22)
(23)
(24)
(25)
(26)
(27)
(28)
(29)
Process
1 some rlzat Ion
Catalytic
Reforming
Fluid-Bed
Catalytic
Cracking
Moving-Bed
Catalytic
Cracking
Vlsbreaklng
Coking
Polymerization
Alkylation
Lube Oil
Processing
Asphalt
Processing
Storage and
Blending
Prime Movers
Electric
Steam
1C
Steam
Genera t ion
Process
Heaters
Process
Typt
Closed
Closed
Open
Open
Open
Closed
Closed
Open
Closed
Closed
Closed
Closed
Open
Closed
Closed
Closed
Open
Open
Open
US Capacity
MM bbl/SD
Jan. . 1972 Feed
0.2 N-Butanc
3.2 Naphtha
4.0 Gas Oil
0.59 Gas Oil
0.23 . Topped Crude,
Vacuum Residual
g Residual ,
0,12 Oleflns
0.6 Isobutane
Oleflns
0.22 Vacuum Gas Oil
Vacuum Residual
0.62 Vacuum Residual
a Process
• Streams
a
a Steam
a Fuel
Any Fuel
Gas-Liquid
Fuels
Products
lEobutane
Aromatlcs
Hydrogen
LPC
Isobutane
Refinery Gas
Gasoline
Heating Oil
Refinery Gas
Gasoline
Heating Oil
Refinery Gas
Fuel Oil
Gas Oil
Refinery Gas
Gasoline
Fuel Oil
Coke
Gasoline
Gasoline
LPC
Lube Oil
Wax
Asphalt
Products
Power
Pover
Power
Steam
Heat
Encrfiy Rc-qulred
Electrical. Fired
Mechanical Steam, Heaters,
Effluents kwhr/bbl Ib/bbl HBtu/bbl
Spent 1.2 20 30
Catalyst
Spent 3-6 0 200-400
Catalyst
Gas from
Regeneration
Flue Gas 0.4-3 (70)-40 0-70
Water
Spent
Catalyst
Flue Gas 0.1-1.5 (60)- 100 100-300
Water
Spent
Catalyst
1.8 (80) 260
Wash Water 15 (100) 350
Flue Gas
Spent 1.2 20 0
Catalysts
Spent Acid 5-10 100-300 0
2-10 100-400 0
Gas from 0.1-3 50-300 100-300
Air- 1 0 5-10
Blowing
Breathing b b 0
and Vent
Gases
None N.A. 0 0
None N.A. N.A. N.A.
Flue Gas N.A. 0 0
Used Oil
Flue Gas b
Ash
Water-
Treatment
Sludges
Flue Cas b - .
« - Not available, large
b - Not available, small
c - All hydrogen treating
d - Ib Bteam/lb HS
c - Million, ions/year
f - M btu/lb sulfur
g - 41,000/tons/sd of coke
( ) - Production ratlicr thnn use
N.A. - Not applicable
-------
03
FIGURE B-l. PROCESS FLOW DIAGRAM OF PETROLEUM REFINING INDUSTRY
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B-5
Companies
As of January 1, 1973, 121 companies operated 245 refineries
in the United States. Table B-2 lists the 16 largest refiners and the
processing capacity of these companies along with the combined capability
(9)
of the other 105 refiners.
The table indicates that refineries of the largest companies
average about 100,000 bbl/day capacity* while the refineries of the smaller
companies average about 20,000 bbl/day. In addition, the smaller refineries
are less complex than the larger refineries.
Size
The largest refinery processes about 400,000 barrels of crude
oil per day and covers 1,100 acres. Refineries with capacities greater
than 100,000 bbl/day process about 56 percent of the total crude oil and
more than 80 percent of the total is processed in refineries exceeding
50,000 bbl/day. On the other hand, operating refineries process as little
as 1,000 bbl/day; however, only special circumstances—such as a remote
location (two new small refineries were built on Alaska's north slope) or
a specialty product, lubricating oil, asphalt, etc.--permit economic operation
of small refineries.
Location
Refineries are located in 39 states. However, 50 percent of the
total capacity is concentrated in Texas, California, and Louisiana, adjacent
to both major oil fields and deep water ports. Other locations with many
large refineries, and perhaps 25 percent of U. S. crude oil capacity, are
* Capacity in the refinery industry is reported on a barrel per stream/day
(BPSD) basis; i.e., the capacity of the unit when operating. Because of
maintenance shutdowns, this capacity is about 5 percent greater than the
long-term capacity of the crude still and 10 percent greater than the
long-term capacity of other process units.
-------
TABLE B-2. LIST OF REFINERS
(1) Exxon
(2) Texaco
(3) Shell
(4) Amoco
(5) Standard (Calif.)
(6) Mobil
(7) Gulf
(8) ARCO
(9) Sun
(10) Union
(11) Sohio/BP
(12) Phillips
(13) Conoco
(14) Ashland
(15) Cities
(If-) Marathon
105 Smaller Companies
TOTAL
No.
Refineries
5
12
8
10
13
9
8
6
5
4
5
6
7
7
1
3
136
245
Crude
Capacity,
bb/sd
1,211,100
1,160,000
1,123,500
1,061,000
1,019,000
969,300
869,800
803,600
496,000
465,900
428,300
422,200
342,500
273,500
245,000
234,500
2,763,500
13,991,580
Cat Cracking
Feed
bb/sd
487,900
443,300
368,000
342,800
208,000
335,200
319,000
210,000
202,000
129,300
144,900
173,800
103,100
119,000
112,500
73,700
739 , 500
4,512,050
Cat
Reforming
273,600
232,600
278,900
243,800
246,000
241,900
227,800
247,000
143,800
122,000
114,500
111,600
79,200
58,000
39,000
57,000
557,200
3,273,918
Hydro-
. cracking
bb/sd
70,900
38,900
105,900
40,000
173,400
47,000
40,400
86,500
26,000
51,000
55,000
22,000
—
—
6,000
22,000
80,000
865,000
Other Hydro
Processing
bb/sd
614,268
329,300
693,500
278,200
234,200
407,600
409,400
390,000
148,300
245,800
170,800
140,200
. 121,900
164,000
51,500
57,500
772,000
5,228,488
Alkylation
81,500
56,200
72,100
47,150
38,700
63,uOO
70,000
28,700
37,200
28,500
22,900
43,100
18,000
14,000
26,000
11,750
153,2^5
812,045
dd
I
-------
B-7
in New Jersey and Pennsylvania serving the East Coast population, and in
Illinois, Indiana, and Ohio near major consuming regions.
Refineries frequently interchange products and raw materials with
neighboring plants of other industries. Common neighbors are petrochemical
plants (which use some of the refinery products and often generate as
byproduct materials similar to some of the refinery intermediate products
which then are sold to the refinery), and electric generation plants (which
may buy fuel from the refinery and supply the refinery with steam and
electric power).
Future Trends
The petroleum industry has been expanding at the rate of about
4 percent per year. With the recent (1972) modification of oil import
regulations and current gasoline shortage, the rate of expansion can be
expected to increase to 5 or 6 percent per year. However, because of lead
times required, the increased rate of expansion is not expected for two or
three years, i.e., until 1976.
Another major future trend in petroleum refining is the increasing
dependence on imported crude oils. The imported crudes contain more sulfur
than the American crudes. Therefore, increased quantities of sulfur will be
entering the refineries and the sulfur will be removed from the oil in
various processes to meet both product quality standards and pollution
control standards. Some refineries cannot process high-sulfur crudes because
of corrosion problems, although these problems can be expected to be solved
by replacing mild steel components with corrosion resistent components during
periodic maintenance shutdowns. Other processing changes can be expected.
Most of the chemical sweetening processes (Process 5)* change the form of the
sulfur in the petroleum rather than remove it. With the higher levels of
sulfur, removal is required. Therefore, chemical sweetening processes are
becoming obsolete, and are being replaced with sulfur removal processes
(No. 7, 8, 9, 10, and 11). The sulfur removal processes require hydrogen,
resulting in use of hydrogen generating processes (No. 6 and 17). Sulfur
plants will also be installed to make sulfur from the hydrogen sulfide
produced by the sulfur removal processes.
* See Page 18.
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B-8
The petroleum industry is already a major supplier of sulfur,
supplying over 1,000,000 tons (10 percent) of about 10,000,000 tons used
in this country. In 1970, only about 25 percent of the sulfur in the crude
oil was recovered as elemental sulfur. With increasing desulfurization of
products, and increasing sulfur in the crude, the industry could become the
largest supplier of sulfur in the country.
Another trend is toward manufacture of nonleaded high-octane
gasolines. Alkylation (Process 23)* and catalytic reforming (Process 17)
capacities are being expanded to meet the demand for higher octane fuels.
Catalytic reforming requires a sulfur-free feed. Naphtha desulfurization
(Process 7) capacity is being expanded to supply this fed. Because of the
higher octane ratings needed, less straight-run gasoline from the still
(Process 3) can be blended into the final product. Catalytic cracking
(Processes 18 and 19), coking (Process 21), and polymerization (Process 22),
also make high-octane components that are blended into lead-free gasoline.
ENVIRONMENTAL IMPACTS
Atmospheric Emissions
The air contaminants emitted from process equipment include
hydrocarbons, carbon monoxide, particulates, sulfur and nitrogen compounds,
and odoriferous materials such as mercaptans. The various processes listed
in Table B-l are classified as open or closed. Open systems vent gases to
the atmosphere in normal operation. The vented gases may be contaminated
and cause pollution. The major open process from an air emission standpoint
is the catalytic cracker regenerator which vents gas from burning of coke
deposits on the catalyst.
Closed systems do not vent process gas to the atmosphere and
emissions would be only from leaks or possibly from the vents of steam
ejector vacuum pumps. Storage tanks are a special case where air in the
tank is contaminated with hydrocarbons and may vent to the atmosphere.
Since the energy required for a 400,000 bbl/day refinery is about
the same as the energy required for a 1,000 megawatt steam electric generating
* See under "PROCESSES" starting on Page B-14.
-------
B-9
station, the potential air pollution from combustion sources in the
refinery is very great. Although particulates and sulfur oxides may be
emitted in somewhat reduced amounts.
Liquid Effluents
Liquid effluents are: condensed steam from various processes,
cooling water from many processes, tank-cleaning wastes, spent chemicals,
and some spilled oil. All refineries have an oil-water separator on the
sewage system to stop oil from being discharged into nearby streams. Process
water is frequently sour (hydrogen sulfide--H2S) so it is stripped of its
acid (H2S) before discharge.
Solid Wastes
The major solid waste from refineries is spent catalyst which
usually is landfilled. Sludges from the cleaning of equipment storage tank,
oil-water separator, etc., and from lube oil manufacture also cause a solid
waste problem. The sludges may be burned or otherwise disposed of.
RAW MATERIALS
The major raw material processed in a refinery is crude oil
(11,210,000 bbl/day).*1 ' A group of materials called natural-gas liquids
(1,699,000 bbl/day) is the other major raw material. Various secondary
raw materials are transferred between refineries and imported. Many materials
are purchased and blended into the products in small quantities; for example,
alkyl lead into gasoline and barium salts into diesel fuel.
Crude oil composition varies widely depending upon its sources.
Petroleum is a mixture of, paraffinic, naphthenic, and aromatic hydrocarbons
containing small amounts of sulfur, oxygen, and nitrogen compounds, plus
trace quantities of various metals such as vanadium and nickel.
Many different chemical compounds (probably over 3,000)^ are
present in crude petroleum and additional compounds are made during refining
processes. The hydrocarbons are generally grouped into series such as the
-------
B-10
paraffins, the olefins, the naphthenes, the aromatics, and polycyclic
compounds.
The sulfur in the crude is a major source of sulfur dioxide
pollution as most of the refinery products ultimately are burned. If the
sulfur is not removed in the refining process, it will be emitted as a
pollutant when the products are used. Sulfur may be present as free sulfur,
hydrogen sulfide, or in organic compounds such as thiophenes, mercaptans,
and alkyl sulfides. The mercaptans are particularly obnoxious from an odor
standpoint and are sometimes oxidized to disulfides to reduce the odor, if
sulfur removal per se is not required.
Natural-gas liquids, which are also called natural gasoline or
casinghead gasoline, are hydrocarbons other than methane in natural gas as
it comes from gas wells. They are separated from the methane by the natural
gas industry and sold to refineries. Natural gas liquids are similar in
composition to various light naphtha streams in the refinery and are blended
and/or processed with them.
Various materials are purchased for their fuel value at the refinery;
natural gas is most common and frequently is used in process heaters. The
steam boiler usually can be adapted to burn any fuel, so the fuel used here
is determined by supply and cost.
Other miscellaneous materials are purchased. The n-butane (feed
to the isomerization process or used for gasoline blendings) is both purchased
from the natural gas industry and supplied by other refinery processes. Many
additives for blending into the various products are purchased; these include
alkyl lead for motor gasoline, barium compounds for diesel fuels, and additives
3Bor lubricating oils such as detergents viscosity index improvers, and
antioxidants.
PRODUCTS
Approximately 2,500 products are currently produced wholly or in
part from petroleum. A record 15,160,000 bbl/day of petroleum products
(2)
were consumed in the United States in 1971. Table B-3 lists the major
petroleum products and their consumption (1971). Most petroleum products
are blends of several refinery streams and the same material often has a
-------
B-ll
TABLE B-3. MA.10R PETROLEUM PRODUCTS, 1971
Product
Gasoline
Jet fuel
Kerosene
Distillate fuel
Residual fuel
LPG and LRG
Miscellaneous
Total
Consump tion
bbl/day
5,992,000
996,000
250,000
2,691,000
2,266,000
1,243,000
1,722,000
15,160,000
Net
Import
51,000
161,000
0
149,000
1,497,000'
25,000(a)
133,000
1,962,000
(a)
Ne t export.
LPG - Liquefied Petroleum Gas
LRG - Liquefied Refinery Gas
-------
B-12
different name when used for a different application. In addition,
individual product specifications may be met by blends having different
compositions when produced at different times or by different refineries.
Gasoline is almost one-half of the refinery output.^ Its value
is more than one-half of the value of all products sold by the refinery.
The gasoline product is invariably a blend of naphthas from several refinery
processes and includes several minor additives such as alkyl lead purchased
from other industries. High octane rating, necessary for high compression
engine fuel, is obtained from aromatic hydrocarbons which have octane ratings
of about 100, naphthenic compound with side chains, and paraffinic hydrocarbons
with several side chains. Butane and isopentane have good octaine ratings,
but the amount of these compounds in gasoline is limited by their high
volatility. Small additions of alkyl lead compounds substantially increase
the octane rating of most gasolines.
Naphtha refers to hydrocarbon fractions boiling in the 90-400 F
temperature range. Gasoline is a naphtha produced for use as motor fuel
and designates both naphthas for blending into motor fuels and the final
product. A single naphtha may be used both as a motor fuel and for other
purposes such as a solvent and on feed to petrochemical industry.
Kerosene is a petroleum fraction boiling in the 350-550 F range.
Historically, it was one of the first petroleum products and was used for
lamps. For this use, kerosene usually is composed of paraffinic hydrocarbons
which cause less smoking when burned in lamps. Various processes were
developed to remove mercaptans from kerosene to reduce odor problems.
Kerosene is used in small scale applications today such as domestic cooking.
Jet aircraft fuels are of two types, a kerosene type boiling in
the 400-550 F range and a naphtha type boiling in the 250-550 F range. These
fuels may be treated to reduce freezing point by removing wax and to reduce
smoking by removing aromatic hydrocarbons.
Light diesel oil distills in 350-575 F range and can have a wide
range of specifications; its performance is measured by a cetane rating that
measures the ignition characteristics of the oil in a diesel motor. Fuels
which naturally have a good cetane rating are used for diesel fuel while those
with a poor rating are made into burner fuel.
-------
B-13
Distillate fuels have similar boiling ranges to diesel oil. Any
oils that can be distilled either in the crude still or in the vacuum still
and oils of similar boiling ranges from various refinery processes are used
as fuel oil. Generally, the oil is treated to remove sulfur. Distillate
fuel is widely used for domestic heating.
Residual fuels are hydrocarbons left in the still after the
volatile hydrocarbons have been distilled off. Most residual oils from the
crude or vacuum still are diluted with kerosene or distillate oil, or
visbroken to reduce viscosity or sulfur content. While residual oils are
not treated to remove sulfur now, processes are being installed in refineries
to remove sulfur from these oils. Residual oils are usually burned in large
boilers used for electric power generation and steam generation in large
industrial plants.
Asphalt is a hydrocarbon residue from asphaltic base crude oils.
It is used with a rock (aggregate) as a cement in road pavement, for manu-
facture of roofing materials, and for many other applications. Petroleum
coke is a residual from the coking process. It is used in the manufacture
of electrodes for electric furnaces and also as a fuel.
Liquefied petroleum gas (LPG) is a mixture of C™, C~, and C^
hydrocarbons. It is widely used for industrial heating and for domestic
heating and cooking where natural gas is not available or scarce. Natural
gas companies frequently add LPG to natural gas at times of peak demand.
LPG is an excellent motor fuel with a high octane rating and minimum air
pollutant emissions. It is occasionally used for truck or bus fleets and
is quite widely used for fork lifts, payloaders, and other applications
inside buildings because of low emissions from motors using LPG. Sometimes
the designation LPG is restricted to a product of the natural gas industry
and when that restriction is made, the same material made by the petroleum
industry will be called liquefied refinery gas (LRG).
The petrochemical industry is based on olefins, LPG's, and aromatic
hydrocarbons, which are secondary raw materials supplied in part by the
natural gas industry. In addition, naphtha is cracked in a thermal cracking
process to make ethylene. The cracking process is performed in both refineries
and petrochemical plants. The refineries have long supplied aromatic
-------
B-14
hydrocarbons to the petrochemical industry. About 3 percent of refinery
output is used to petrochemical feedstock.
PROCESSES
Twenty-nine pertinent processes used in petroleum refineries are
shown in Figure B-l along with the flows of intermediate products among
processes. Other refinery processes are not shown because (1) the process
is a minor variation of a process shown, and the raw materials, products,
and wastes are not significantly different from those in that process;
(2) the process is a specific application, perhaps obsolete, and is not
typical of the industry; or (3) the process, while performed in some refineries,
is more typical of a different industry. Two variations of catalytic cracking
are shown because their wastes are different. Each variation has several
additional modifications, but they are not shown because the raw materials ,
products, and wastes are the same. A third variation, fixed-bed catalytic
cracking, is not shown because the process is no longer widely used. Other
processes, such as cracking naphtha to make ethylene, are considered part of
the petrochemical industry and are not described, even though the processes
are sometimes performed in a refinery.
Process heaters and process drives are treated as if they were
processes because their emission is characteristic of the heater or drive
and not of the particular process. Thus, the emissions and wastes shown for
each process do not include those from heaters or drives. Emission from the
heaters and drives are proportional to the energy requirements for the process.
A brief description of each of the 29 processes follows including
information on processing techniques, equipment, raw materials, products,
energy requirements, and wastes.
Crude Storage (1). Crude oil delivered to a refinery is stored
in tanks until processed. The storage tanks are sized to receive the
largest single shipment expected and to assure continuous operation of the
refinery. The amount stored may be anywhere between a 2-week and a 2-month
supply. The crude is stored in large cone or floating roof tanks of up to
-------
B-15
250,000-barrel capacity. After storage, the oil is sent to the desalter if
required and then to crude distillation.
Only a small amount of electrical energy is required for pumping
of the stored crude.
Gaseous hydrocarbon emissions from storage tanks relate to three
basic mechanisms: breathing loss, working loss, and standing storage loss.
These are discussed later under storage and blending (Process No. 26). Less
than 0.5 gal of water per bbl settles to the bottom of crude oil tanks and
is sewered. This water effluent often contains salt. Some crude oils form
sludges at the bottom of the storage tanks which are removed periodically and
burned (usually in the steam boiler).
Desalting (2). The function of desalting is to remove salt, water,
and water-soluble compounds from crude oil. Water is added to the oil and
thoroughly mixed. The wet oil is heated to break the emulsion. The water is
separated by decantation and sewered. In a variation of the process an
electrostatic coalescer is used to separate the oil and water. The desalted
crude is then fed to the crude still. Desalting is often performed in the
oil field by the oil producing industry.
The thermal energy requirement for desalting is about 22,000
Btu/bbl assuming a 250 F desalting temperature and is usually obtained by
heat exchange with one of the hot streams from the crude still. Alternatively,
the oil may be heated with steam or a fired heater. About 0.01 kwh of
mechanical energy per barrel is required to pump the oil through the system
and to operate the electrostatic coalescer.
No gaseous emissions or solid wastes are produced from the process.
About 2 gal of wastewater per barrel are drained from the desalter. This
water contains any water-soluble material that had been in the crude and
frequently is high in salt content. The wastewater volume is not very
large—about 140 gpm from a 100,000-bbl/day refinery.
Crude Distillation (3). The function of crude distillation is to
separate desalted crude oil into various products or intermediate products
with different boiling points by distillation and steam stripping. The major
items of equipment in crude distillation are the process heater (pipe heater),
-------
B-16
main distillation column, and stripping column. The number of product streams
varies with the particular refinery.
The intermediate products are light naphtha, heavy naphtha,
kerosene, distillate or diesel oil, gas oil, and topped crude. In a very
simple refinery the intermediates are naphtha from the top of the still,
gas oil from a side stream, and topped crude from the still bottom. In a
complex refinery three to five side streams may be withdrawn.
In Figure B-l, the wet gas is shown as being processed further in
the gas plant. However, in some refineries, this processing--the separation
of light gases from their naphtha component--is performed as part of crude
distillation. The naphtha is blended into motor fuels or any of several of
the refinery products, or further processed to improve octane rating and/or
reduce sulfur content. The kerosene may be chemically sweetened or hydrogen
treated and sold directly or sent to blending. The distillate or diesel oil
may be sold for diesel or fuel oil, hydrogen treated, hydrocracked,
catalytically cracked, or blended. The gas oil may be sold as fuel oil,
hydrogen treated, hydrocracked, catalytically cracked, or blended. The
topped crude is usually the feed to the vacuum distillation process although
it may be sold for fuel, blended into fuels, hydrogen treated, or
catalytically cracked.
The installed capacity for crude distillation in the U. S. was
13.7 million barrels per stream day in 1971. The capacity of a crude still
varies from about 1,000 to 200,000 barrels per day. The crude still is one
of the largest items of equipment in the refinery.
Energy requirements include process heat from a heater, steam,
and mechanical drives. About 100,000 Btu/bbl of crude are required from
the process heater. The process heater associated with the crude still
consumes 15 to 30 percent of the fuel used in a refinery and for the largest
unit--200,000 barrels per day—the heat release in the heater is similar to
the heat release in a boiler supplying a 100 MW electric generator. About
15 pounds of steam per barrel of crude are required to pump the raw materials
and intermediate products.
No atmospheric emissions or solid wastes are produced under
normal operating conditions. The steam used is condensed with the light
naphtha in the condenser, separated from the oil by decanting, treated to
-------
B-17
remove acids and odors, and sewered. Operating conditions have little or
no effect on wastewater. The amount of hydrogen sulfide in the wastewater
is determined by the crude oil feed.
Vacuum Distillation (4). Vacuum distillation separates the
atmospheric residue from the crude still into a heavy residual oil and one
or more heavy gas oil streams. The major items of equipment are the process
heater, the vacuum still, and the steam ejectors for producing the vacuum.
The installed capacity for vacuum distillation is 4.9 million barrels per
day (1971), which indicates that almost all of the topped crude is vacuum
distilled.
Depending mainly upon the crude feedstock and partially upon the
individual refinery, the residual oil intermediate product may be sent to
the asphalt plant, thermally cracked in a coker to make gasoline, cracked
in a visbreaker to make distillate fuel oils, blended into a fuel oil, or
hydrogen treated to remove sulfur and then blended into a fuel oil. With
suitable feedstocks the residual is sent to the lube oil process for
manufacture into lubricating oil. The heavy distillate fraction from a
paraffinic crude charge is sent to the lube oil plant either directly or
thro'igh a hydrogen treating process. Other distillates are treated
similarly to the gas oil stream from the crude still and catalytically
hydrocracked, catalytically cracked, or used as fuel oil. The vacuum gas
oil may be processed to remove sulfur by hydrogen treatment before catalytic
cracking or use as a fuel oil. Refinery-to-refinery variations are minor.
About 50,000 Btu/bbl of thermal energy are required from a process
heater. The product streams from vacuum distillation are usually cooled by
heat exchange with the feed to the crude still to conserve energy. About
8 pounds of steam per barrel are required to operate the steam ejectors and
to strip the residual and side streams of their lighter fractions. From 0.1
to 0.2 kwhr of mechanical energy per barrel are needed for pumping.
The vent gas from the steam ejectors contains about 130 Ib of
hydrocarbon vapors per 1,000 barrels of feed. The steam used in the injectors
is condensed in a barometric condenser. The condensate may contain some oil.
The wastewater eventually passes through an API oil-water separator, where the
oil is removed before discharge of the water. No solid wastes are generated.
-------
B-18
Chemical Sweetening (5). Chemical sweetening removes mercaptans
from petroleum products to improve odor. At least 11 different processes
are used for this purpose including contacting the petroleum material with
various caustics, hypochlorites, solvents, or catalysts. In most processes,
mercaptan sulfur is oxidized to an alkyl disulfide which is less obnoxious
than the mercaptan. A few of the solvent processes separate the mercaptan
which then becomes a product. The amount of petroleum products chemically
sweetened is not known. A chemical sweetening process is installed in most
of the older refineries while many newer refineries have replaced it with a
final hydrogen treatment before blending.
The energy required by the process is minimal. Steam is used to
strip mercaptans from solvents, but the solvent stream is much smaller than
the petroleum stream. About 0.01 kwhr of mechanical energy per barrel is
required for pumping.
Depending on the process, atmospheric emissions, liquid, and solid
wastes are produced in small quantities. In some processes, the oxidizing
chemical is regenerated by air blowing. In these processes air, slightly
depleted :a oxygen, is emitted. The amount of air used is proportional to
the amount of mercaptan oxidizer. In hypochlorite processes, water containing
sodium or calcium chloride is drained. The amount of salt is small and
proportional to the amount of mercaptan sulfur oxidized. In one of the
processes clay is used as a carrier for a copper chloride treating chemical
and when the clay is inactivated it is sent to a landfill.
Hydrogen Plant (6). The hydrogen plant supplies hydrogen for
hydrogenation reactions. Frequently, all hydrogen is supplied by catalytic
reforming so that a hydrogen plant is not needed. Hydrogen is made by
reacting naphtha or other hydrocarbons with steam at 1,400-1,600 F. The
required temperature is obtained by external heating or by burning part of
the hydrocarbon with oxygen rather than air to prevent dilution of the product
hydrogen with nitrogen as illustrated in Figure B-2. The gas from the reactor
contains hydrogen, steam, carbon monoxide, and carbon dioxide, and is passed
through a shift reactor where CO and H-0 are catalytically reacted to form
carbon dioxide and more hydrogen. The carbon dioxide is removed by adsorption.
The small quantity of carbon monoxide remaining is catalytically oxidized
-------
B-19
Hydrocarbon
Steam
^
Steam
-*
Preheatei
Reformer
T
Cooler
•^
^
Shift
Converter
>
co2
absorber
f
t
Second
Converter A
\
Absorbent
Regenerator
co2
bsorber
/
- Absorbent
2 Regenerator
CO,
FIGURE B-2. HYDROGEN PLANT.
-------
B-20
with steam to carbon dioxide and hydrogen and the last traces of carbon
dioxide are absorbed with caustic or amine. The hydrogen is dried before
use by condensation of water at high pressure. Single units as large as
10,000 scfm have been installed.
Thermal energy from steam is needed to strip the. carbon dioxide
from the absorber solution. Steam in about the same quantity is generated
by cooling the gases from the partial oxidation of the feed in a boiler.
With external heating about 300,000 Btu/bbl of feed are required. However,
a substantial fraction can be recovered by heat exchange with the product.
A small amount of mechanical energy is required for compression of the feed
and pumping of the fluids through the systems if a liquid feedstock is used
or about 4 kwhr/bbl are required if a gasoline feedstock is used.
The only waste stream from the process is a carbon dioxide
atmospheric emission from regeneration of the absorber liquid. From 0.25
to 0.5 cubic foot of carbon dioxide is produced per cubic foot of hydrogen.
Naphtha Hydrogen Treatment (7). The function of the gasoline
hydrogen treatment is to remove sulfur from a naphtha stream, saturate
olefins '.o reduce gum formation, and/or remove aromatics from naphthas for
solvents, burning fuels, or jet fuels. For gasoline treatment, the feed is
mixed with about 400 cu ft of hydrogen per barrel, heated in a fired heater
to 350-800 F and passed through a catalyst bed. The pressure is from 300 to
800 psi. The products are cooled, usually by heat exchange with the feed,
and the excess hydrogen is separated and recycled. The gasoline product is
reheated and steam stripped or distilled to remove hydrogen sulfide. A total
of 4.9 million barrels per day (1971) of petroleum products are hydrogen
treated, and 2.8 million barrels per day of catalytic reforming feedstock
(naphtha( are hydrogen treated. The process product may be catalytically
reformed or blended directly into a refinery product. The off-gas and
hydrogen sulfide go to gas processing for further treatment.
Fired heaters require up to 50,000 Btu/bbl of gasoline treated.
Since the reaction is exothermic, in some process variations all the necessary
heat is supplied by the reaction. From 30 to 90 Ib of steam per barrel are
required to strip hydrogen sulfide from the gasoline. About 1.5 kwhr of
-------
B-21
mechanical energy per barrel are required to compress the hydrogen and to
pump the feed through the system.
A gas stream containing carbon monoxide is emitted during
infrequent (months to years) regeneration of the catalyst. The catalyst is
regenerated by blowing a steam-air mixture through the bed to burn off a
carbon deposit. A liquid stream of sour water is drained from the stripper
in an amount equal to the steam used. The spent catalyst comprises a solid
waste; however, catalyst life is usually more than 5 years. The catalyst
is sold to a reclaimer of precious metals in some instances.
Kerosene Hydrogen Treatment (8). The function of the kerosene
hydrogen treatment is to remove sulfur from kerosene, saturate olefins,
reduce gum formation, and remove aromatics. The kerosene is mixed with about
400 cu ft of hydrogen per barrel and heated in a fired heater to 400-800 F
at 500-800 psi. It is then passed through a catalyst bed where the reaction
occurs. The products are cooled, usually by heat exchange with the feed,
and the excess hydrogen is separated and recycled. The products are reheated
and steam stripped to remove hydrogen sulfide. A total of 4.9 million barrels
per day (1971) of petroleum products are hydrogen treated. Most kerosene—
1,000,000 bbl/day--is treated by a chemical sweetening process or by a
hydrogen treatment. A total of 1,000,000 bbl/day of middle distillate stocks
(mainly kerosene) are hydrogen treated. The treated kerosene is usually a
refinery product or blended into a product. The hydrogen sulfide goes to gas
processing.
Fired heaters require up to 70,000 Btu/bbl of kerosene treated.
Since the reaction is exothermic, in some process variations all the necessary
heat is supplied by the reaction. About 8 Ib of steam per barrel are required
for the stripping of hydrogen sulfide from the product. From 0.5 to 2 kwhr of
mechanical energy per barrel are required to compress the hydrogen and to pump
the feed through the system.
The emissions for this process are about the same as those for the
Gasoline Hydrogen Treatment Process (7) except the internal between catalyst
regeneration is weeks to months.
-------
B-22
Gas-Oil Hydrogen Treatment (9). The function of the gas-oil
hydrogen treatment is to remove sulfur from oils. The gas oil is mixed with
from 750 to 1,500 cu ft of hydrogen per barrel and heated in a fired heater.
The mixture then is passed through a catalyst bed where the reaction occurs.
The pressures are from 500 to 800 psi. The products are cooled, usually by
heat exchange with the feed, and the excess hydrogen is separated and recycled.
The products are reheated and steam stripped to remove hydrogen sulfide. A
Total of 4.9 million bbl/day (1971) of all petroleum products are hydrogen
treated. The fraction of gas oil that is hydrogen treated is not known.
However, at present, sulfur specifications in fuel oils are met by desul-
furizing gas oil to a very low sulfur content and blending with residual oils.
A total of 295,000 bbl/day (1973) of cat cracking feedstock (a part of gas
(9\
oil) is hydrogen treated. The treated gas oil may be catalytically cracked
or blended into a fuel oil product. The hydrogen sulfide goes to gas processing.
The fired heaters require from 5,000 to 70,000 Btu/bbl. From 1 to
10 Ib of steam per barrel are required for the stripping of hydrogen sulfide
from the product. From 2.5 to 9 kwhr of mechanical energy per barrel are
required to compress the hydrogen and to pump the feed through the system.
Emissions from this process are the same as those from the Kerosene
Hydrogen Treatment Process (7).
Lubricating Oil Hydrogen Treatment (10). The function of the
lubricating oil hydrogen treatment is to remove sulfur, hydrogenate olefins,
remove gem forming compounds, improve color, and improve viscosity index of
lubricating oils. The feed is mixed with 100 to 200 cu ft of hydrogen per
barrel, heated in a fired heater, and is passed through a catalyst bed where
the reaction occurs. The products are cooled, usually by heat exchange with
the feed, and the excess hydrogen is separated and recycled. The oil is
reheated and steam stripped to remove hydrogen sulfide. The fraction of
lubricating oil that is hydrogen treated is not known. The hydrogen-treated
oil is sent to lube oil processing for further treatment and the hydrogen
sulfide stream is sent to gas processing.
Fired heaters require from 35,000 to 140,000 Btu/bbl of oil treated.
From 15 to 30 Ib of steam per barrel are required for the stripping of
-------
B-23
hydrogen sulfide from the product. About 2.5 kwhr of mechanical energy
per barrel are required to compress the hydrogen and to pump the feed
through the system.
Emissions from this process are essentially the same as those
from the Gasoline Hydrogen Treatment Process (7).
Residual Oil Hydrogen Treatment (11). The function of the
residual oil hydrogen treatment is to remove sulfur from the oil usually
to about 0.3-0.5 percent concentration. The feed (3 to 5 hexant sulfur) is
mixed with recycled hydrogen and from 400 to 700 cu ft of fresh hydrogen per
barrel and heated in a fired heater to 650 -850 F. It then is passed through
a catalyst bed where the reaction occurs. The pressure is about 1,000 psi.
The products are cooled, usually by heat exchange with the feed, and the
excess hydrogen is separated and recycled. The product is reheated and
steam stripped to remove hydrogen sulfide. The first residual oil hydrogen
treatment units are now going on stream and are fairly small. The
desulfurized residual oil is blended into fuel oil. The hydrogen sulfide is
further treated in gas processing.
Fired heaters require from 10,000 to 100,000 Btu/bbl. From 3 to
25 Ib of steam per barrel are required to strip hydrogen sulfide from the
product. From 1 to 4 kwhr of mechanical energy per barrel are required to
compress the hydrogen and pump the feed through the system.
Emissions from this process are similar to the Gasoline Hydrogen
Treatment Process (7) emissions.
Catalytic Hydrocracking (12). The function of the catalytic
hydrocracking process is to convert a gas oil in the presence of hydrogen
at 700-2,000 psi and 500-800 F into lighter, sulfur free, more valuable
petroleum fractions. Catalytic hydrocracking generally opens the ring
structure on polycyclic aromatics and naphthenes. Paraffins, single-ring
naphthenes, and single-ring aromatics are resistant to hydrocracking. About
(9)
840,000 bbl/day (1972) of petroleum intermediates are hydrocracked.
Hydrocracking differs from hydrogen treatment in severity of treatment
rather than type of treatment. The process variations are based on feed
and catalyst used and include single or two-stage processes. The feed is
-------
B-24
usually a gas oil although occasionally residual oil or naphtha is fed.
From 1,000 to 2,000 cu ft of hydrogen per barrel are consumed. The product
from the reactor is separated by distillation into a wide range of sulfur-
free hydrocarbons lighter than the feedstock and some hydrogen sulfide.
Intermediate products are furnished to a variety of processes as indicated
below.
Intermediate Product Process to Which Furnished
Hydrogen sulfide Gas processing
Hydrocarbon gases Gas processing
Light naphtha Blending into gasoline
Heavy naphtha Catalytic reforming
Blending into gasoline
Blending into solvents
Kerosene Blending into jet fuel
Gas Oil Blending into fuel oil
Blending into diesel oil
Catalytic cracker
Recycle
Residual Pitch (product)
The oils produced by catalytic hydrocracking are sulfur-free
saturated hydrocarbons which make then premium fuels for burning in jet
engines and diesel engines, but poor fuels for automotive-type engines.
From 100,000 to 250,000 Btu of process heat per barrel from a
fired heater are required to heat the reactor feed. About 18 Ib of steam
per barrel are required for stripping and 24 Ib/bbl are generated in a
waste heat boiler which cools the product. From 1 to 6 kwhr of mechanical
energy per barrel are required for compression of the hydrogen and pumping
of the feed and products through the process.
Atmospheric emissions--mainly carbon monoxide — result from
regeneration of the catalyst. Since regeneration is infrequent (about 4
per year), the carbon monoxide produced should not be a problem. A liquid
stream, mainly condensed steam with some H«S, is drained from the stripper.
The spent catalyst, a solid waste, is not produced in significant amounts
becau'se the catalyst life is several years. The spent catalyst is sold to
a reclaimer of precious metals occasionally.
-------
B-25
Gas Processing (13). The function of gas processing (frequently
called the gas plant) is to stabilize light naphtha by removing gaseous
hydrocarbons from it, and separate the various fractions of hydrocarbon
gases. Amine stripping, which removes hydrogen sulfide from the gases, is
sometimes considered part of gas processing although it is treated as a
separate process in this study. In some refineries, gas-processing equip-
ment is associated with each gas-generating process while in most new
refineries gas processing is performed in a facility serving the entire
refinery.
The separations are performed by a series of distillation and
absorption operations, the number of operations being one less than the
number of products. Gas processing can be a simple scheme producing fuel
gases composed of butane and more volatile hydrocarbons, and a.light
naphtha; or a complex scheme producing methane, ethane, ethylene, propane,
propylene, isobutane, butylene, butadiene, n-butane, isopentane, amylene,
n-pentane, and a light naphtha.
The disposition of products and intermediate products is shown
below.
Prod uc t Use
Methane Refinery fuel
Ethane Refinery fuel
Petrochemical feedstocks
Ethylene Petrochemical feedstock
Refinery fuel
Propane LPG
Petrochemical feedstock
Propylene LPG
Petrochemical feedstock
Polymerization
Alkylation
Isobutane Alkylation
Butylene Alkylation
Polymerization
Butadiene Petrochemical feedstock
n-butane Isomerization
Fuel
Blend into gasoline
-------
B-26
Product Use
Isopentane Blend into gasoline
Amylene Alkylation
Blend into gasoline
n-pentane Isomerization
Blend into gasoline
Light naphtha Blend into gasoline
Catalytically reform
Blend into solvents
Isomerization
Figure B-3 *s a flow diagram for a plant of intermediate complex-
ity which uses an absorption system. The gases from the refinery initially
are compressed. The high-boiling petroleum gases and gasoline are absorbed
in a heavy naphtha or kerosene. In the flow diagram, methane, hydrogen
sulfide, and ethane pass from the top of the absorber de-enthanizer unit.
The ethane and methane are stripped of hydrogen sulfide with diethanola-
mine and used for fuel gas. The propanes and less volatile components flow
from the bottom of the absorber to the debutanizer where propane and butanes
are separated from the gasoline by distillation. The depropanizer is
another distillation column which separates butanes from propane.
Thermal energy is required for the distillation column and strip-
ping the absorber solutions. This energy may be supplied by hot process
streams from other processes rather than from a fired heater or steam.
Mechanical energy, about 2 kwhr/bbl, is required to compress the gases for
absorption as the distillation column normally operates under pressure.
The process is performed in a closed system and no emissions are
generated.
Amine Stripping (14). The function of the amine stripper is to
strip hydrogen sulfide from hydrocarbon gases by absorption in an amine
solution. Sour gas from gas processing is the feed and the intermediate
products are a sweet gas which is returned to gas processing and hydrogen
sulfide which goes to the sulfur plant. The hydrocarbon gas containing
hydrogen sulfide is contacted with an absorbent solution, such as
-------
B-27
DISTILLATE
DISTILLATE FROM
_CRUOE UNIT a CO
-------
B-28
diethanolamine, in an absorption column to absorb selectively the hydrogen
sulfide. Hydrogen sulfide is absorbed at a pressure of around 150 psi,
and the absorbent solution is stripped at atmospheric pressure by boiling
at the bottom of the stripper.
Thermal energy, about 1 Ib of steam per Ib of H9S, is required
to strip the hydrogen sulfide from the absorber solution. About 0.5 kwhr
of mechanical energy per barrel is required to pump the liquids through
the system.
No atmospheric emissions are produced. When diethanolamine is
used as the absorbent solution, about 1 gallon of spent solution is
drained per thousand barrels processed. However, since 10,000 to 20,000
gallons may be drained at one time, the impact on the sewage system of
changing solutions may be severe. When monoethanolamine is used for the
absorbent solution, about 1 Ib of waste complex salts (solid) is removed
from the system for each 3,000 barrels processed. No other waste is gen-
erated. The amount of waste is roughly proportional to the amount of
hydrogen sulfide removed from refinery streams and, therefore, depends
upon the amount of sulfur in the crude and the extent to which the pro-
ducts are desulfurized.
Sulfur Manufacture (15). Sulfur is manufactured in a Glaus
plant as a method of disposal of hydrogen sulfide. About 1.2 million
tons/year of sulfur is produced by the petroleum industry and this number
is growing. The feed is hydrogen sulfide from the amine stripper. Where
special market conditions exist, sulfur dioxide or sulfuric acid may be
made using processes typical of the sulfur industry. As indicated by the
flow diagram in Figure B-4, the hydrogen sulfide is burned with a substoichio-
metric quantity of air to make sulfur and water. The off-gas is cooled and
the sulfur condensed as a liquid. About 60 to 70 percent of the sulfur is
removed in the burner; the remaining hydrogen sulfide and sulfur dioxide
gases are reheated and passed through a catalytic converter. The gases
are cooled to condense liquid sulfur. In most systems, two to four con-
verter stages in series are built into the system. Fifty to 60 percent
of the remaining sulfur is removed in each converter stage. The total
sulfur recovery in Glaus plants varies from about 80 to 95 percent.
-------
B-29
I
I
I
r
i
i
i
Burner Stage
Steam
Converter Stage
Sulfur
H2S ^
Air
Reaction
Furnace
/
^
^=^
Boiler
\
T
.so2
Desorber
-^
so2
Abso
"*^
Condenser
reatment Stage
Off-Gas
rber
Incinerator
- Air '
\
n
PoK
\
eat
/
Converter
\
/
Condenser
Sulfur
-I
Fuel
J I
FIGURE B-4. GLAUS PLANT
-------
B-30
Frequently, the tail gas from the Glaus plant is treated to
remove the last traces of sulfur-containing gases. The tail gas contains
H2S, S0_, COS, and CS , compounds that have a disagreeable odor. In old
plants they are incinerated to reduce the odor problem, although S09 emis-
sions result from burning. Some new processes essentially add more con-
verter stages to the Glaus unit, other absorb the sulfur-containing off-
gases, concentrate them, and recycle them to the Glaus input, and still
others oxidize hydrogen sulfide to sulfur in a wet process. While tail-
gas treatment plants are being installed, long operating experience and
standard design have not yet evolved. In the flow diagram (Figure B-4)
the off-gas from the Glaus plant is incinerated to convert all of the sul-
fur into S07 which then is absorbed. In the Wellman-Lord process for S0_
removal and recovery a sodium sulfite solution is used for absorption while
in other processes an amine solution is used. The clean off-gases are
vented to a stack. The absorber solution is regenerated and the SO- is
fed back into the Glaus plant.
The Glaus plant requires a fired heater, 400 Btu/lb of sulfur,
to reheat the off-gases in the catalytic states, and a small amount of
mechanical energy to move the gases through the plant. Steam, 4 Ib per
Ib of sulfur, is generated in a boiler utilizing the heat content in the
products of combustion following the burner stage.
The emissions from the Glaus plant are primarily unconverted
H S and S0_. Hydrocarbons in the feed to the Glaus plant form carbonyl
sulfide and carbon disulfide which are also emitted. If the off-gas is
incinerated, all sulfur compounds are converted to sulfur dioxide. Negli-
gible liquid and solid wastes are generated. In a refinery where most of
the sulfur in the crude is removed and collected as H«S, the emissions
from the Glaus plant constitute the major sulfur emissions. As sulfur is
removed from products and high sulfur foreign feedstocks replace sweet
U.S. crudes, the emissions from the sulfur process will increase. A large
100,000-barrel-per-day refinery using a 1-percent sulfur feedstock removing
sulfur from its fuel gases and desulfurizing many of its products and using
an efficient Glaus plant which converts 95 percent of the feed into sulfur,
emits 5 to 6 tons of sulfur per day from the Glaus plant. About 127,000 tons
per year of sulfur dioxide are emitted from sulfur manufacture in all
refineries.
-------
B-31
Isomerization (16). The function of isomerization is to process
normal butane, pentane, or hexane into the corresponding isoparaffin. Iso-
butane is used as a feedstock for alkylation. Isopentane and isohexane
have a higher octane rating than normal pentane and normal hexane and are
blended into gasoline. The process equipment consists of a heater, a
reactor, and a set of distillation columns. The distillation columns
frequently are shared with the alkylation process which uses the isobutane,
or the distillation procedure may be included in gas processing. The
reactor normally operates at 300 to 400 psi and at 400 to 500 F.
About 1.2 kwhr of mechanical energy per barrel is needed to pump
the feed to the operating pressure. A fired heater (30,000 Btu/bbl) is
used to heat the feed, and steam (20 Ib/bbl) heaters are used to drive the
distillation columns.
The process is closed and should have no gas emissions or liquid
effluents in normal operation. The solid catalyst is replaced after about
2 years of operation. The spent catalyst is sold to reclaim its platinum
value.
Catalytic Reforming (17). Catalytic reforming is used to con-
vert low-octane naphtha into a high-octane gasoline, produce aromatics for
the petrochemical industry, and to manufacture hydrogen. In 1971, about
3.2 million bbl/day of naphtha was reformed. The feed naphtha is reformed
by passing it through a multiple-stage reactor with reheat between stages
to maintain the temperature at 900-1100 F. Paraffins are dehydrogenated
to naphthenes, naphthenes are dehydrogenated to aromatics, olefins are par-
tially hydrogenated to paraffins, long and short chain hydrocarbons are
cracked to gaseous hydrocarbons, and short chain hydrocarbons are isomer-
ized. The process variations include methods of catalyst handling, differ-
ent catalysts, and different operating conditions. One factor affecting
process choice relates to product usage for either petrochemicals or
gasoline. Another factor is the nature of the feedstock.
Reforming process throughput presently is 3.2 million barrels
per day which makes it one of the very large volume processes in refineries,
Additional facilities are being built rapidly because the reformer yields
high-octane blending stocks used to minimize the need for lead additives.
-------
B-32
In addition, the hydrogen from reforming is needed for the hydrogenation
processes which remove sulfur from petroleum products. The reformer is
a major user of energy in the refinery and the associated process heater
is one of the larger heaters in the refinery.
The feed to the process is any desulfurized naphtha (sulfur
poisons the catalyst). Heavy naphthas usually are fed when making gaso-
line, and light naphthas when making aromatics for the petrochemical
industry. The products from the reformer are a high-octane gasoline or
an aromatic petrochemical feedstock, propane, butanes, ethane, and 800-
1500 cubic feet of hydrogen per barrel of feed. The gasoline has a clear
(without lead addition) octane rating of 90-92 with existing units and 98-
102 with new units and is blended with lower octane gasolines for sale.
The propane is sold or used as fuel and the hydrogen is used for desulfur-
izing, hydrocracking, or for fuel.
The energy required by the process is 200,000 to 400,000 Btu/bbl
and is supplied from a fired heater to heat and reheat the feedstock., From 3
to 6 kwhr are required for compression and to pump the fluids through the
system. Usually no steam is used although a few processes use up to 30 Ib
of steam per barrel to heat the reboiler in a product fractionator.
The only atmospheric emissions are from regeneration of the cata-
lyst. Usually the catalyst is regenerated by burning off carbon deposits
at infrequent intervals; however, in some variations, the catalyst is con-
tinuously withdrawn from the reactor and regenerated. The major constituent
of the emission is carbon monoxide at 0.002 to 0.02 Ib/bbl (the amount of
CO formed is independent of batch or continuous regeneration) or about
30 Ib/hr in a large refinery that may typically reform 40,000 bbl/day.
This is a very small source and is about equal to the emissions from a
catalytic cracker with maximum controls and is less than the emissions
from the process heater. Since the catalyst is mechanically stable and
the feed is sulfur-free, very little particulate or sulfur emission is
produced from catalyst regeneration. Because of the low emission rate,
emission controls are not used. No liquid wastes are generated. The spent
catalyst is a solid waste and may be processed for recovery of precious
metal values or sent to a landfill. The amount of solid waste generated
is small.
-------
B-33
Fluidlzed-Bed Catalytic Cracking (18). The function of the
catalytic cracking process is to convert distillate oils into high-
octane gasoline, raw materials for alkylate production, petrochemical
raw materials, heating and diesel oils, and liquefied petroleum gases.
About 3.9 million bbl/day (1971) of oil is fed into fluid-bed catalytic
crackers not including a 22 percent recycle. Two major process varia-
tions are the fluidized bed and the moving bed. Since the emissions
from the two systems are different, they are discussed separately in this
report. The fluidized-bed units are built in sizes up to 75,000 bbl/day
with 40,000 bbl/day being typical.
In the fluidized-bed catalytic cracker, hot gas oil is fed into
a line at the bottom of the reactor where it mixes with the catalyst.
The gas oil is cracked as it passes up through the reactor. The cracked
products leave the top of the reactor, are cooled, and fractionated in a
distillation column associated with the reactor into the product streams.
In a single pass, 50 to 80 percent of the feed is converted into lighter
hydrocarbons. Some or all of the unconverted gas oil may be recycled.
The catalyst flows to the regenerator where the carbon is burned off with
air. In about 50 percent of the units, the flue gas is burned in a carbon
monoxide boiler, while in others the CO-rich flue gas is emitted to the
atmosphere.
The major process variations involve catalyst handling and
reactor design. In one variation, the reaction takes place in the riser
line which becomes the reactor. In another variation, the recycle and
virgin feed are reacted in different risers to obtain a more severe treat-
ment of the recycle oil.
The feed to the catalytic cracker may be any hydrocarbon stock
from kerosene to vacuum gas oil or deasphalted residual oil. The feed is
usually the distillate oils from the crude and vacuum stills, the heavy
oils from coking and hydrocracking, and a large recycle heavy oil stream.
A complete range of petroleum products is made in the catalytic
cracker and a large distillation column is associated with the cracker to
separate these components. The amount of each product can be varied by
changing operating conditions. The coke deposited on the catalyst is
-------
B-34
burned during regeneration to supply some of the heat required by the
process. The products and their special characteristics and uses are
listed below.
Gases Rich in isomers Further processed in
and olefins gas processing
Naphtha Rich in high-octane Blend into gasoline
components
Light oils -- Fuel
Recycle
Residual -- Fuel
Recycle
Incidental to the process, the sulfur concentration in the light and
residual product oils is reduced to about 50 percent of the concentra-
tion of sulfur in the feed. The partial desulfurization makes these oils
more desirable fuels. In addition, the product oils are more easily desul-
furized than the feed oil.
Thermal energy (up to 70,000 Btu/bbl) may be used to preheat the
feed. Steam (about 40 Ib/bbl) is used to strip the spent catalyst and
fractionate the product. Mechanical energy (0.3-4 kwhr/bbl) is used to
drive the air blowers and feed pumps. The flue gases are usually cooled
by heat exchange in a boiler, and the carbon monoxide is burned in a
boiler. The amount of steam generated (about 110 Ib/bbl) may be greater
than the steam used.
The flue gas (about 2,000 cu ft/bbl) from the catalytic cracker
is a major atmospheric emission from a refinery. The flue gas is a mix-
ture of carbon monoxide and nitrogen with traces of hydrocarbon and sulfur
compounds and, in the absence of a carbon monoxide boiler, contains most
of the carbon monoxide emitted by a refinery. At present, almost all of
the 4.5 million tons per year of carbon monoxide emitted by catalytic
crackers comes from units without CO boilers. The volume of stack gas
from a catalytic cracker is similar to that from a large industrial boiler
or a small electric-generating boiler. In a fluidized-bed catalytic
cracker the catalyst is in the form of a coarse powder and the action of
the fluid-bed grinds the powder into a fine dust, some of which passes
-------
B-35
through the dust-collection system. This dust is a major source of partic-
( R ^
ulate emission (33,000 tons per year*) from refineries. About 5 percent
of the sulfur in the feed deposits in the coke on the catalyst and the sul-
fur is oxidized in the regenerator and leaves in the flue gas.
Analyses of the stack gas show that 15-60 percent (usually 30-50
percent) of the sulfur^12^ is emitted as S<>3 and the remainder as S02. Thus,
the catalytic cracker is a major sulfur emitter (333,000 tons per year as
SO *) in refineries. Hydrocarbons (165,000 tons per year*) and nitrogen
oxides (50,000 tons per year*) are emitted in significant amounts by cat-
alytic crackers. A liquid waste stream from the fractionator is the
condensed steam from the process. This water is sour and is combined and
treated with other sour waters before release. About 0.1 Ib of catalyst
is used per barrel of feed, so that about 2 tons per day of solid waste
are generated by a 40,000-bbl/day unit.
A variation in refinery operation which may reduce the atmos-
pheric emissions of SO is desulfurization of the feed to the catalytic
cracker. This change has been made in some refineries for economic
reasons, and it has been suggested as a general method of meeting antici-
pated sulfur dioxide limits on the regenerator stack gas. Caustic scrub-
bing of the regenerator gases also has been suggested and Exxon plans to
install a sodium carbonate scrubber in a refinery where disposal of the
sodium sulfite solution generated will not be a problem.
Moving-Bed Catalytic Cracking (19). The function of the moving-
bed catalytic cracking is the same as fluidized-bed catalytic cracking.
510,000 bbl/day are fed into moving bed catalytic crackers not including
a 20-percent recycle. The feeds and products are also similar. The
moving-bed units are generally smaller than the fluidized-bed units.
Large units may process up to 35,000 bbl/day and 15,000 bbl/day units
are typical. The catalyst is in the form of beads, 1/8 to 1/4 inch in
diameter. The catalyst is added continuously to the top of the reactor,
flows through the reactor and regenerator by gravity, and is removed from
the bottom of the regenerator. An airlift station elevates the catalyst
* Calculated from throughput and emission factors.
-------
B-36
from the bottom of the regenerator to the top of the reactor. The hydro-
carbons flow down through the reactor and the combustion air can flow up
cz down thtougl. ti.Ł. regenerator depending upon the particular process
variation. CO boilers have not been used in moving-bed crackers.
Thermal energy (100,000-300,000 Btu/bbl) is required to heat
the charge to reaction temperature. More heat is required than in the
i
fluidized-bed process because less heat from hot regenerated catalyst is
available. Steam (100 Ib/bbl) is required by the fractionator and to seal
the gases in the reactor from the gases in the regenerator. Mechanical
energy (0.1-1.5 kwhr/bbl) is required for blowing air into the regenerator
and Lcr pumping oil. Steam (160 Ib/bbl) can be generated by the hot off-
gas from the regenerator.
The emissions from the moving-bed cracker are less than from
fluidized-bed system, primarily because of the smaller size of the moving-
bed units. Tne catalyst perticles are larger and less dust is generated.
Slightly less carbon deposits on the particles in the bed so that less
carbon monoxide and sulfur dioxide are emitted. Hydrocarbon and nitrogen
oxide emissions are small. The wastewater quantity is about the same as
the steam used. The water is sour and is treated before release. The
spent catalyst from the process is a solid waste and amounts to 0.1 to
0.2 Ib/bbl. In a large unit, this amounts to more than a ton per day.
Visbreaking (20). The function of visbreaking is to thermally
crack residual oils into a lighter oil under mild conditions (850-890 F).
The residual oil is passed through a heater to crack it and then fraction-
ated in atmospheric and vacuum towers. About 230,000 bbl/day (1971) of
residual oil are visbroken and a similar amount of gas-oil is thermally
cracked in a similar process (not shown in flow diagram). The light oil
product is used to cut (dilute) the vacuum residue from the visbreaker
which is then sold for heavy fuel oil. The light product is sometimes
used as a feed to a catalytic cracker. Visbreaking is more typical of
foreign refineries than American refineries.
-------
B-37
The main energy requirement is 260,000 Btu/bbl from a fired
heater to crack the oil. Mechanical energy (1.8 kwhr/bbl) is needed to
pump the oil. Steam (100 Ib/bbl) is generated by cooling and condensing
the cracked oil and about 20 Ib/bbl are used in the fractionating tower.
Since the process is closed, no atmospheric emissions are pro-
duced. Water from fractionation is treated with other sour water. No
solid waste is generated.
Coking (21). The function of coking is to crack heavy residuals
into a full range of hydrocarbon products and to produce petroleum coke.
About 20 percent of the feed is converted into coke (42,000 ton/day). Most
coking processes are closed, although about 10 percent of coking is performed
in a fludized-bed process (an open process) where combustion of some of the
coke is used to supply the process heat. The off-gas from the combustion
chamber in a fluidized-bed process is burned in a CO boiler and emitted to
the atmosphere.
In a closed, drum-coking process, the oil is heated to 900-930 F
and then passed into a coking drum where it is cracked into lighter hydro-
carbons and coke. Normally two coking drums are installed and one is used
while the other is emptied. The volatile hydrocarbons are fractionated.
In the open, fludizing-coking process, hot oil is cracked in a reactor con-
taining a bed of coke at 930-950 F. The heat for the process is supplied
by burning part of the coke in a second fluidized bed called the burner
where the coke is heated to about 1100 F. The off-gas from the burner is
oxidized in a CO boiler to remove CO and conserve heat.
The feed to the coker is usually a heavy residual oil from the
vacuum still or the catalytic cracker, or a deasphalted oil from asphalt
manufacture. The products of the coker are a wide range of hydrocarbons
similar to the products of catalytic cracking and are used similarly.
About 20 percent of the feed is converted into coke which is burned as
fuel or sold to make carbon electrodes.
In the drum coking process, from 300,000 to 400,000 Btu/bbl
are used to heat the feed in a fired heater. In the fluid coker this
heat is supplied by burning coke rather than using a fired heater.
-------
B-38
About 80 Lb of stem per barrel are used in the fractionator and 180 Ib of
steam per barrel are generated by cooling the hot products of coking.
Thus, the process generates 100 Ib of steam per barrel. Mechanical energy
(1.5 kwhr/bbl) is needed for high-pressure water jets to wash the coke
from the drums, for compressing air, and to pump fluids through the process.
No atmospheric emissions are produced in the drum-coking process.
In the fluidized coking process, the thermal energy is supplied by burning
the coke to carbon monoxide. The carbon monoxide may be used in a boiler
associated with the process or used for fuel at other places in the refin-
ery. About 5 percent of the carbon in the feed is burned and emissions
are typical of this combustion. Presumably the sulfur content of the feed
would be distributed in a manner similar to a catalytic cracker where the
sulfur concentration in the coke is slightly less than the sulfur concen-
tration in the feed. Therefore, 3-5 percent of the sulfur in the feed
would be emitted with the product of combustion. Both coking processes
fractionate the product and the steam used for stripping is condensed and
sent to the sour-water stripper. In the drum-coking process, high-pressure
water jets are used to break the coke from the drums and the water from
these jets goes into the plant sewers. No solid wastes other than coke
dust is generated.
Polymerization (22). The function of the polymerization process
is to produce a high-octane gasoline or petrochemical feedstocks from ole-
fin gases. It is used in some refineries in place of isomerization and
alkylation (the generally preferred process). The olefins are passed over
a catalyst such as phosphoric acid at 500 psi and 275-375 F. The feed-
stock is an olefin stream of ethylene, propylene, butylene, and/or amylene
from gas processing. The products are high-octane gasolines or petrochem-
ical feedstocks and petroleum gas which is used for fuel.
Energy from a fired heater is required only on startup because
the reaction is exothermic and the feed is heated by heat exchange with
the product. Steam (20 Ib/bbl) is used for fractionation of the product.
Mechanical energy (1.2 kwhr/bbl) is required to pump the feed liquid.
-------
B-39
Since the process is closed, there are no atmospheric emissions.
Phosphoric acid is a liquid catalyst which may be washed from the reactor
during a maintenance operation. Sometimes the phosphoric acid is absorbed
on a solid support and the support and acid is sent to a landfill when the
catalyst is replaced. The quantities of liquid and solid waste are not
significant.
Alleviation (23). The function of alkylation is to synthesize
high-octane gasoline by reacting olefins, such as butylene, with isobutane.
812,000 bbl/day (1972) of alkylate is produced. In other processes, per-
haps more typical of the petrochemical industry, benzene is alkylated with
ethylene or propylene to make petrochemical feedstocks. Anhydrous hydro-
fluoric acid or sulfuric acid is the catalyst used. The feedstock is an
olefin and isobutane from the isomerization process and/or gas processing.
Previously, only butylene was used, but now propylene and amylene are often
alkylated. The product is high-octane gasoline. Propane is an undesired
diluent in the feed and is a product of the fractionating tower associated
with alkylation. Since the alkylation process is one of the few processes
capable of yielding high-octane unleaded fuel, it is being installed in
numerous refineries and present capacity is increasing.
Two process variations are employed: a sulfuric acid catalyst
(536,000 bbl/day); or an anhydrous hydrofluoric acid catalyst (276,000
bbl/day) (1972)^ . The major difference is in temperature of operation
(80 F for the hydrofluoric-acid process, and 45 F for the sulfuric-acid
process). Hydrofluoric acid is regenerated in the process by fractiona-
tion while sulfuric acid is regenerated outside of the process.
Energy from fired heaters is not required. Steam (100-300 Ib/bbl)
is needed to fractionate the intermediate product. The quantity of steam
required is large because the recycle isobutane stream must be fractionated
from n-butane, a diluent. Mechanical energy (0.5-5 kwhr per barrel) is
required to compress the feed and recycle gases, and in the sulfuric acid
process for refrigeration.
-------
B-40
No atmospheric emissions are produced. About 17 Lb of 90 percent
sulfuric acid per barrel are wasted from the sulfuric-acid process. The
sulfuric acid is returned to the sulfuric acid plant for regeneration. The
feed acid strength is about 98 percent. The products, when using either
catalyst, are given a caustic wash and 20 Ib of spent caus.tic solution per
barrel are disposed of. No solid waste is produced.
Lube Oil Processing (24). The function of the lube oil process
is to make a lube oil stock suitable for blending into lubricating oils
from selected distillate and residual feedstocks. Widely differing pro-
cesses are used depending upon the feedstock, the ultimate use, and the
period of equipment installation. In the traditional process, the feed
oil is contacted with sulfuric aciu which reacts with unsaturates and
polyaromatics and forms a sludge. The sludge is removed by filtration
with clay.
Another process (Duol-Sol) employs two solvents: propane which
selectively extracts paraffinic hydrocarbons (lube oils) and rejects
asphaltic hydrocargons, and cresylic acid which preferentially dissolves
asphaltic and naphthenic hydrocarbons. The two solvents flow in a counter-
current manner through a series of extraction stages. The feedstock is
introduced near the middle of the unit. The solvents are removed by dis-
tillation from the lube oil and asphalt.
After removal of asphalt, selective solvents and refrigeration
are used to separate waxes from lubricating oils. In one dewaxing opera-
tion, propane is added to reduce the viscosity of the oil, the oil is
chilled to below its lowest anticipated operating temperature, and wax is
crystallized out and separated by filtration.
The preferred lubricating oils are a high-boiling paraffin with
several side chains. Normal paraffins are unsatisfactory components for
low-temperature operation because of their high melting point. Naphthenic
compounds can be used only within a narrow temperature range because their
viscosity changes rapidly with temperature. Polyaromatics and unsaturated
compounds form sludges and varnishes when present in lubricating oil and,
therefore, are unsatisfactory. Therefore, the preferred feedstocks is an
oil rich in paraffins and lean in other hydrocarbons.
-------
B-41
The products of lube oil processing are lubricating oils (which
are blended into the many different lubricants), waxes, fuel oil, and
asphalt.
Lube-oil processing is a large source of sludges in a refinery.
The used clays from filtration represent a major solid waste. The oils
are washed with caustic solutions at various points in the process, thus
generating a liquid waste stream. The lube-oil process is a major user of
steam and mechanical power in the refinery.
Fired heaters are not usually used in processing lube oils.
Depending upon the process, 100 to 400 Ib of steam are required per
barrel, primarily for separation of solvents. Mechanical energy require-
ments are large (2 to 10 kwhr/bbl) for refrigeration and pumping the oil
through filters.
Lube-oil processing is not a major source of air emissions. In
some processes the oil is blown with air, but since the boiling point is
high, no serious emission occurs. In other processes a decolorizing clay
is regenerated by burning the sludge adsorbed on it, producing small atmos-
pheric emissions.
The liquid waste from the process is condensed steam from the
solvent stripping which is pure. The sludge from the acid-clay process
is frequently burned in the refinery boiler. The clay is a solid waste.
In at least one lub-oil refinery the sludge was lagooned and stored until
the lagoon accidentally ruptured creating water pollution.
Replacement of the acid-clay process with a solvent process
reduces the amounts of sludge formed.
Asphalt Production (25). The function of the asphalt process is
to make asphalts from residual oils of asphalt-based crudes. About 644,000
(2)
bbl/day (1972) of asphalt is produced. Asphalt is high molecular-weight
hydrocarbon containing polycyclic aromatic rings. Some residual oils have
the desired properties and require no treatment. In others, the asphalt
stock is oxidized to increase the melting point by blowing air through the
residual oil. During air blowing, the residual oil is heated to about
500 F. The reaction is exothermic and after initial heatup, additional
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B-42
heat is not necessary. Air blowing is stopped when the asphalt reaches
the proper consistency. Other asphalts are produced by mixing the feed-
stock with propane followed by separation of a solid asphalt fraction
and a liquid nonasphalt fraction. The products are sold to the various
asphalt-based industries, such as roadbuilding, roofing paper, and seal-
ant manufacture.
Energy from fired heaters (100,000 to 300,000 Btu/bbl) is re-
quired in the solvent process primarily for stripping the solvents from
the asphalt and the deasphalted oil. About 5,000 to 10,000 Btu/bbl are
needed in the air-blowing process to heat the feedstock to the reaction
temperature. Fifty pounds of steam per barrel are used to strip the
solvent in the solvent process. If most of the energy is derived from
fired heaters, little is needed from steam and vice versa. Mechanical
energy (0.1 to 3 kwhr/bbl) is required for the solvent process mainly
for agitation of the extractor stages. About 1 kwhr/bbl is needed to
compress air for the air-blowing reaction.
The solvent process is closed and no atmospheric emissions are
formed. While the air-blowing process emits gases to the atmosphere, the
quantity is small since the asphalt previously has been distilled at a
high temperature. Sometimes air-blowing produces an obnoxious odor and
the off-gas is used for combustion air in a nearby heater. The condensed
steam from the solvent stripping operation is a wastewater stream. No
solid waste is produced.
Storage and Blending (26). The function of storage and blend-
ing is to store intermediate products and to mix or blend the various
intermediate products into final products. The materials are stored in
large tanks, which are pressurized for liquefied gases, specially vented
for liquids with high vapor pressure, specially constructed for materials
of moderate vapor pressure, and vented for materials of low vapor pressure.
Liquids are blended in a blending tank by agitation. Essentially all raw
materials, intermediate products, and products are stored in tanks. Most
products are a blend of several intermediate products and perhaps purchased
raw materials.
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B-43
No fired heater is used with blending and storage. A negligible
amount of steam is used to heat tanks containing heavy residual oils. A
negligible amount of mechanical energy is required for pumping and agitation.
Hydrocarbon emissions from storage vessels depend on three basic
mechanisms: breathing loss, working loss, and standing storage loss.
Breathing and working losses are associated with cone-roof tanks and stand-
ing storage losses are associated with floating-roof tanks. Breathing
losses are hydrocarbon vapors expelled from the vessel by expansion of
existing vapors due to increases in temperature or decreases in barometric
pressure. Working losses are hydrocarbon vapors expelled from the vessel
during emptying or filling operations. Emptying losses result from vapor
expansion caused by vaporization after product withdrawal. Filling losses
are the amount of vapor (approximately equal to the volume of input liquid)
vented to the atmosphere by displacement. Breathing and emptying losses
are usually restricted to fixed-roof tanks vented at atmospheric pressure.
Filling losses are experienced in fixed-roof tanks and low-pressure storage
tanks vented to the atmosphere. Both working losses and breathing losses
can be significant. Standing storage losses from floating-roof tanks are
caused by the escape of vapors through the seal between the floating roof
and the tank wall, the hatches, glands, valves, fittings, and other open-
ings. The magnitude of hydrocarbon emissions from storage vessels depends
on many factors including the physical properties of the material being
stored, climatic and meteorological conditions, and the size, type, color,
and condition of the tank.
The annual hydrocarbon emissions from crude oil, gasoline, and
distillate tanks are estimated at 1.3 million tons. At present, 75 per-
cent of these tanks are equipped with floating roofs. The annual estimated
emissions constitute about 3 percent of the total national hydrocarbon
emissions and about 7 percent of the 18.6 million tons/year emitted from
all stationary sources. Minor liquid and solid waste quantities are gen-
erated by maintenance operations.
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B-44
Prime Movers (27). The function of the prime mover is to supply
mechanical energy to pumps, blowers, compressors, etc. About 7.5 kwhr of
mechanical energy are required per barrel of crude processed in a modern
refinery. Electrical drives are usually the most convenient, especially
for smaller units. For large units, steam turbines are typical; gas tur-
bines or internal combustion engines occasionally are used. On some equip-
ment more than one drive is installed to assure continuous operation. For
example, an electric motor and a steam turbine may drive the same pump,
one unit being used normally and the other unit being on standby in case
of failure of the primary driver. The steam turbine is especially appli-
cable in a refinery since steam is normally distributed at about 400 psi
and used at 175 or 30 psi. A steam turbine is used both to supply mechan-
ical energy and low-pressure steam to a process.
Electricity and steam are secondary sources of power and the
fuel is burned at a place remote from the process using the energy. A
gas tu bine would burn either refinery gas or natural gas and a diesel
engine would use a diesel oil.
The process emissions are typical of drives and not peculiar to
the refining industry. Since most drives are steam or electric, the
emission relating to the mechanical energy is at the site of steam or
electric generation and not at the process site.
jSteam Generation (28). The function of steam generation is to
supply steam to the various processes for direct use in the operation, for
heating, and to drive steam turbines. Frequently, steam is used for elec-
tric power generation. Overall about 30 to 100 pounds of steam are used
per barrel of crude oil processed at a refinery. In a refinery processing
about 100,000 barrels of oil per day, about 250,000 Ib/hr of steam are
used. If the refinery generates its own electricity (not usual practice),
the boiler is typical of one used in the electric power industry and prob-
ably operates at a steam pressure of 1000 psi or higher. Steam for distri-
bution at 500, 175, and 15 psi is supplied from bleeds off the turbine
driving the electric generator. If the refinery does not generate elec-
tricity, steam is generated at about 500 psi in a boiler typical of large
industrial boilers. Steam for distribution at 175 and 15 psi is obtained
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B-45
by reducing the pressure of 500 psi steam and from steam turbines exhaust-
ing at the lower pressures. In addition to generation in the main boiler,
steam is generated by boilers in several of the processes. The largest
steam generator associated with a process is the carbon monoxide boiler
on the exhaust from the catalytic cracker. Waste-heat boilers may be
placed in the flue gas streams for process heaters. In some processes,
the process fluids are cooled by generating steam. Most of these boilers
would generate steam at one of the lower distribution pressures.
A steam generator is used as an incinerator for combustible
liquid and solid wastes. Spilled oil, sludges, and residues from main-
tenance operations such as tank cleaning are usually incinerated in a
steam generator.
Table B-4 lists the amounts of the different fuels used at
refineries. Most of the nongaseous fuels and some of the gases would be
burned in the steam generators. From 10 to 20 percent of the fuel used
in a refinery is burned in the steam generator. Also while the industry
average energy demand is 700,000 Btu/bbl, many newer complex refineries
use only 500,000 Btu/bbl.
The process emissions from the steam generator are typical of
conventional steam generators and the fuel used. In the past, various
oily wastes, sour gases, and high sulfur oils have been burned in the
steam generator, but since pollution control regulations are becoming
more stringent, the use of such fuels is decreasing. Liquid wastes are
generated by treating boiler feed water but present a minor problem.
Solid wastes include ash from the fuels such as acid sludge and coal, and
sludges from treatment of boiler feed water.
Process Heaters (29). The function of the process heaters is
to heat various process streams. Most of the fuel used in a refinery is
burned in process heaters. Steam heaters can be used at operating temper-
atures up to about 400 F and above that temperature fired heaters are
required. In addition, superheated steam is required by a few processes
and the steam usually is superheated in the fired heater associated with
that process. A pipe heater, as shown in Figure B-5. is the standard fired
-------
B-46
TABLE. B-4. REFINERY FUEL AND ENERGY SOURCES (1969)
Fuel
Fuel Oil, 1000 bbl
Acid Sludge, 1000 bbl
Coal, 1000 tons
Natural Gas, MMcf
Refining Gas, MMcf
Petroleum Coke, 1000 tons
Purchased Electricity, MMkwhr
LPG, 1000 bbl
Purchased Steam, MMlb
Total Energy Equivalent,
1012Btu
Crude Oil Run to Stills, MM bbl
Energy Consumption, Btu/bbl
Quantity/year
43,323
95 v
570
997,886
984,561
10,625
17,927
6,620
24,396
-
3,880
703,000
10 2Btu/year
263
0
14
998
1,000
320
61
25
27
2,728
-
—
of Crude Oil
-------
B-47
OIL INLETS
OIL
OUTLET
OIL/CAS BURNERS
FIGURE B-5. PIPE HEATER
(4)
-------
B-48
heater in the petroleum industry. In this heater, liquid petroleum passes
through tubes exposed to a hot combustion zone. The oil enters at the top
of the heater and is heated convectively and countercurrently by the flue
gases. The oil is then passed into the tubes on the side walls of the
furnace where it is heated by radiation. Steam superheater tubes, if any,
are placed at the top of the furnace just below the oil tubes. The process
heater on the crude still is larger than most industrial boilers and in the
largest still is comparable in size to the steam boiler for a 100 megawatt
electric generator. The heaters for catalytic reforming, catalytic crack-
ing, and coking compare in size with large industrial boilers. In processes
wita less throughput, the units may be fairly small and compare in size to
a package steam boiler.
Most process heaters are equipped to burn gas or oil or both.
The pipe heater usually cannot be adapted easily to solid fuels.
The emissions from the pipe heater are those typical of indus-
trial boilers. Particulate emissions result from ash in the fuel and
unburned carbon that pass through the furnace. Hydrocarbon emissions
result from incomplete combustion. Sulfur dioxide is formed from the
sulfur in the fuel. Nitrogen oxides are formed by reaction with N? in air
at the high combasLion temperature. Carbon monoxide is formed because of
incomplete combustion of the carbon in the fuel. Each of these emissions
is at a low concentration but the total represents a major emission because
of the large amounts of fuel burned. Table B-5 lists estimated emissions
from combustion sources calculated from emission factors^ ' and fuel con-
sumed in the petroleum refining industry.
TABLE B-5. ESTIMATES OF ATMOSPHERIC EMISSIONS FROM COMBUSTION
SOURCES IN PETROLEUM REFINING INDUSTRY (1969)
Emissions,
Emission Type 1.000 short tons/year
Particulate 60
Sulfur dioxide 270
Carbon monoxide 1.9
Hydrocarbons 42
N0v 500
-------
B-49
WASTE CONTROL METHODS
In addition to specific control devices associated with partic-
ular processes, the refinery employs emission control equipment that serv-
ices the entire refinery--for example, flares for control of atmospheric
emissions, and water treatment facilities for wastewater. As indicated
previously, the steam generator usually is used to incinerate combustible
wastes.
Flares
The function of the flare is to burn gases released in emergency
situations from any process in the refinery. In the past, flares have
been used to burn unwanted gases, but at a modern refinery, combustible
gases are used for their fuel value. Flares also had been used to vent
and incinerate sour and malodorous gases, but pollution control regula-
tions have reduced this practice. At the present time, if an equipment
malfunction requires an emergency reduction in pressure in a large process
vessel, the gases are vented to a flare to eliminate fire hazards. A flare
consists of a burner, pilot light, and air injection system. Excess process
gases are sometimes vented to the flare at a very high rate and for short
times more gas may be burned in the open or a stack might be built around
the flare to reduce light and noise and to prevent hazards to nearby pro-
cess equipment.
The flare requires a small pilot flame and steam to promote smoke-
less combustion.
The atmospheric emissions caused by a flare depend upon the gas
vented; for example, sulfur in the gas will form S09. A modern flare is
smokeless, and particulates, carbon monoxide, and hydrocarbons are not
emitted in quantity. Since the flare is a flame device, NO is undoubtedly
X
made and emitted. The total quantity of materials flared over a period of
a year is small; therefore, the emissions from the flare should be small.
However, large quantities occasionally are flared which may cause a tempo-
rary air pollution problem.
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B-50
Wastewater Treatment
Wastewater treatment removes impurities from water effluents.
A refinery produces many types of wastewater streams such as used process
and cooling water, storm drainage, and sanitary sewage. Much of the waste
process water is contaminated with hydrogen sulfide and other compounds
with obnoxious odors. This sour water is boiled and treated with acid to
remove hydrogen sulfide in a sour-water stripper. The sour-water stripper
is usually a packed tower perhaps 10 feet in diameter and 30 feet or more
high. About 10 gallons of sour water are treated per barrel of oil pro-
cessed. The products are sweet water and hydrogen sulfide gas (the latter
is sent to a Glaus plant).
Storm drainage and process water are usually sent through an API
oil-water separator which decants the oil from the water. The API separ-
ator is a large item of equipment.
Sanitary sewage and any high BOD process water would be treated
in a biological treatment plant similar to a sewage plant for a small
city.
The energy requirements for water treatment are small except
for steam used by the sour-water stripper. It uses about one pound of
steam per gallon of water treated.
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B-51
REFERENCES
(1) Anon., "1972 Refining Processes Handbook", Hydrocarbon Processing,
51 (9), pp 111-222 (September, 1972).
(2) Anon., Oil and Gas Journal, .70, p 128 (March 27, 1972).
(3) Anon., Oil and Gas Journal, 70. p 92 (January 31, 1972).
(4) Bell, H. S., American Petroleum Refining, Fourth Edition,
D. Van Nostrand, Princeton (1959).
(5) Nelson, W. L., "Petroleum (Refinery Processes", Encyclopedia of
Chemical Technology, Volume 15, pp 1-77, Wiley and Sons, New York.
(6) Anon., "1973 Gas Processes Handbook", Hydrocarbon Processing,
/:2 (4), pp 91-128 (April, 1973).
(7) Anon., "Background Information for Proposed New Source Performance
Standards", APTD 352a, USEPA, Research Triangle Park, pp 31-36
(June, 1973).
(8) Wollaston, E. G., Forsythe, W. L., Vasalos, I. A., "Sulfur
Distribution in FCU Products", API Division of Refining,
Proceedings 1971, p 12-42.
(9) Anon., Oil and Gas Journal 71, p. 96, April 2, 1973.
(10) American Petroleum Institute, "Petroleum Facts and Figures, 1971
Edition, Washington.
(11) USEPA "Compilation of Air Pollutant Emission Factors, Second Edition",
AP-42, Washington, 1973.
(12) Baker, Kenneth, USEPA, Private Communication to Herbert Carlton, BCL,
February 11, 1974.
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C-l
APPENDIX C
THE SECONDARY NONFERROUS METALS
INDUSTRIAL PROCESS PROFILE
INDUSTRY DESCRIPTION
The history of the metals recycling industry can be traced back
to antiquity. Records of ancient peoples give evidence of crude melting
techniques that existed at the dawn of civilization. Archaeologists believe
the rudimentary recovery of iron, lead, and copper occured in earliest times.
But, recycling, as we know it today, is the development of the
past 100 years. During this period, scientific and sophisticated technology
has been developed to transform waste material into valuable products.
More significantly, the volume of scrap expanded with the growth of
industrialization, particularly in the United States, which, today, has
the largest and most effective recycling industry in the world.
More than 3 million tons of nonferrous scrap metals are recovered
annually by secondary smelters, refiners, ingot manufacturers, fabricators,
foundries, and other industrial consumers in the United States. In its
total operation of metallics, the U. S. recycling industry is an $8 billion
industry,* occupying a major role in the economic life of the country.
And the growth potential of the secondary industry is substantial.
In recent years the concept of recycling has come to the fore
impelled by increased concern for the environment, the awareness of
dwindling natural resources, and the realization that solid waste
accumulations could choke urban society. Recycling does represent the
most affirmative environmental response and a highly constructive economic
response to the critical challenge of solid waste disposal.
Furthermore, various studies have indicated that the world's
resources are fast being depleted. Obviously, recycling must play a major
role in future conservation considerations.
* Fine, P., Rasher, H. W., and Wakesberg, S., Operations in the Nonferrous
Scrap Metal Industry Today, published by NASMJ, New York, New York (1973).
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C-2
The companies that make up the secondary nonferrous metals
industry are generally small and generally are not well equipped to deal
with the development and application of new technology for the control of
pollution. They lack the needed technical capabilities and financial
resources. However, they are concerned about the environment and are
making efforts to reduce the pollution potential of the industry. These
efforts could be accelerated by partial support through demonstration
projects from the government, since such support might encourage industry
to undertake additional work.
DISCUSSION OF SECONDARY NONFERROUS METALS
INDUSTRIAL PROCESS PROFILE
The Secondary Nonferrous Metals Industry consists of what may
be considered for purposes of this analysis to be industry "segments" that
convert scrap metals or waste materials to products that are marketed for
use or consumed in the form they exit from the process. Each segment is
comprised of companies that are considered competitors in the production
of the same products. The secondary industry and each segment of the
industry have an identifiable population of companies and have a degree
of commonality with respect to raw materials consumed, process employed,
products produced, environmental control problems, pollutants produced,
and control equipment used.
Detailed description of the processes for each segment follows.
Segments
The Secondary Nonferrous Metals Industry consists of about 20
segments. The major segments in regard to volume of metal recovered from
scrap are:
(1) Copper Segment
(2) Brass and Bronze Segment
(3) Lead Segment
(4) Aluminum Segment
(5) Zinc Segment
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C-3
The minor segments are:
(1) Tin
(2) Nickel
(3) Cobalt
(4) Magnesium
(5) Mercury
(6) Antimony
(7) Precious Metals
(8) Titanium
(9) Selenium
(10) Cadmium
(11) Germanium
(12) Hafnium
(13) Zirconium
(14) Indium
(15) Beryllium
Major Companies
The Secondary Nonferrous Metals Industry encompasses a host of
companies. For example, in 1973, there were 125 companies producing
secondary aluminum, 130 companies producing secondary lead, and 44 companies
producing secondary copper and brass and bronze products. The size of
these companies ranges from small family-owned facilities to large
corporations. The major companies are identified at the end of each
segment description which follows.
These companies are found throughout the United States. However,
in most cases, as noted in Figures 1, 2, 3, and 4, which show the major
location of secondary aluminum, zinc, copper, and lead segments, they are
found in the vicinity of populated areas where the scrap generally is found.
Manufacturing Operations
Manufacturing operations fall into 3 basic categories: (1) scrap
pretreatment, (2) smelting/refining, and (3) casting (product formation).
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C-4
r\
I. New Englond
2. Middle Allonlic
3. Soulh Allonlic
4. Eon North Cenlrol
5. Cost Souih Ceniroi
6. W«l North Cenlrol
9
Weil South Cenlrol
Mounloin
Pacific (includes Alaska
and Hawaii)
FIGURE C-l. AVERAGE VOLUME IN TONS PER YEAR OF (1) ALUMINUM SCRAP.
PROCESSORS, AND (2) ALUMINUM SCRAP CONSUMERS, BY REGION, 1969
Source: Extensive Survey
IV16
2343
NotCi Volume in nel tons
I. Mew England
2. MiODlr Allonlic
X. Souifi Allonlic
4. Cast Norm Cenlrol
5. Coil Soulh Control
C. Weil 1,'orlri Ctnlrol
7. Weil Soulh Central
C. Mountain
9. Pacific (irtclutfci Aloslo
and HowOii)
FIGURE C-2. VOLUME OF COPPER HANDLED BY
TYPE OF RECYCLE BY REGION
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C-5
(I) Zinc Scrap
Processor
'(2) Zinc Smeller
I. New England
2. Middle AiioMic
5. South Atlantic
4. Eosl North Cenlrol
5. Cost South Centre I
6. West North Ctnlrol
7. Weil South Cenlrol
8. Mountain
9. Pacific (include! Alosko
ond ilowoiil
FIGURE C-3. AVERAGE SIZE IN TONS PER YEAR OF ZINC OF (1) ZINC
SCRAP PROCESSORS AND (22) ZINC SMELTERS, BY REGION, 1969
Source: Extensive Survey
: 1:1(1) Lead scrop processor
KM
~](2) LcaJ smelter
foil Horlh Ctolrol
CO»I SOulh CtnlfOl
\Vi\t tloilh Central
(y Vftil South Cenlrcl
(i[l) Mounlan
(V) Pocldc (lncl«d««
Alatlo on
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C-6
In scrap pretreatment, the scrap is treated by a number of processes to
densify it and/or to separate the nonferrous metal from gross impurities
to render the scrap more amenable to smelting. Smelting is an operation
whereby the scrap is partially purified by heat. From the smelting
operation, the scrap is given a final purification in the refining
operation and finally cast into the desired form.
Processes
Processes comprise specific arrangements of equipment that
accomplish chemical or physical transformation of the scrap materials into
end products, intermediate products, and waste materials. Other process
outputs include waste streams to the air, water, and land. When two or
more different combinations of process steps accomplish the same chemical
or physical transformation but have different environmental impact, each
combination is a distinct process. An example of a process is Fire/Refining
in the Copper Industry. Black copper and/or blister copper are treated in
the molten state to remove residual metal values and produce a fire-refined
copper melt. Other process outputs include atmospheric emissions, liquid
wastes, and solid wastes.
Process Steps
Process steps are the basic components of a process that utilize
process equipment or materials handling equipment, not including control
equipment. In each case where a piece of process equipment has two or
more cycles or phases with distinctly different emissions to the atmosphere,
such cycles can be considered sequential process steps. An example of a
process step is blowing the melt with air in the fire-refining process.
Future Trends
Modern technology, environmental effects, and the shift in the
flow of raw materials are all having a direct impact on the secondary
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C-7
nonferrous metals industry. For example, the characterization of the
raw materials is changing. Low-grade scrap which at one time was
disposed of by landfill is now being recycled to the secondary industry.
Large volumes of metal-laden dust are no longer emitted to the atmosphere
but are collected in dust control equipment. The collected dust becomes
a source of raw material to the secondary industry.
ENVIRONMENTAL IMPACTS
Atmospheric Emissions
The secondary nonferrous metals industry is one of the sources
of environmental pollution. The pollution may be in the form of atmospheric
emissions, liquid wastes, and solid wastes. Atmospheric emissions
generally contain particulate and gaseous materials, both of which are
sources of pollution and potential health hazards.
The composition of the atmospheric emissions depends on the
segment of the industry from which the emissions are derived. However,
it has been established that the industry as a whole emits such metallic
materials as lead, zinc, mercury, arsenic, cadmium, antimony, precious
metals, magnesium, nickel, copper, manganese, and aluminum.
Emissions factors for atmospheric emissions for every segment
of the industry are not available although it can be said that, in many
cases, significant quantities are emitted. For example, the raw emissions
factor for metallic zinc sweating process with zinc chloride was reported
to be 10.8 Ib of particulates/ton of scrap, whereas the raw emission factor
for sweating residual scrap was reported at 24.5 Ib/ton of scrap processed.
Morphology of the particles is dependent on the type of scrap,
segment from which the particulates are generated, and many other factors.
In most cases, the particulates1 sizes range from less than 0.1 micron to
several microns. Particle shape will vary from spherical to irregular shapes,
Gaseous emissions also depend on the segment of the industry
•and the processing step. In general, atmospheric emissions may contain,
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in addition to the combustion products, harmful materials like sulfur
oxides, halides, inorganic acids, hydrocarbons, and ammonia.
A substantial portion of the pollution from the industry comes
from the burning of fuels to provide energy for the processes.
Quantitatively, data are not available on the energy demand for this
energy. However, the primary sources of energy for the secondary non-
ferrous metals industry are: (1) natural gas, (2) fuel oil, (3) coke,
and (4) electricity. Data on quantities of energy consumed by this
industry are not readily available.
Emission of Liquid Wastes
The secondary nonferrous metals industry can be a significant
source of liquid wastes as water is used for many applications throughout
the industry. For example, in the aluminum segment, aqueous wastes are
generated principally in these operations: cooling molten aluminum alloy,
wet scrubbing of fumes during chemical magnesium removal, and the wet
milling of aluminum melt residues such as dross and slag. Ingots and
shot are cooled with water by direct contact with the mold and metal.
Magnesium content in aluminum alloys is adjusted by the chemical removal
of magnesium using either chlorine or aluminum fluoride. Wastewaters
containing very large levels of suspended and dissolved solids are produced
during the welj; .rail.ling of^resjLdues containing aTuminum.
Another example is the copper segment, where wastewater is
generated in 15 of 25 processes.
Composition of these aqueous wastes depends on the segment of
the industry generating the wastes. Some of the wastes are simply cooling
water and can be recycled with a minimum of treatment. Other wastes contain
a wide variety of soluble and insoluble metallic and nonmetallic materials.
An example of the contaminants in the aqueous wastes for the secondary
aluminum industry is shown as follows.
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C-9
Composition of Aqueous Waste
From Aluminum Segment
Sulfate
Chloride
Fluoride
Aluminum
Calcium
Copper
Magnesium
Nickel
Sodium
Zinc
Cadmium
Lead
Manganese
Oil
Grease
Phenols
Also, metal values such as arsenic, mercury, and barium are
found in the aqueous wastes. While many of these heavy metal values may
be harmless, metals such as cadmium, mercury, and arsenic are known to
be toxic.
In summary, the secondary nonferrous metals industry is a potential
source of aqueous wastes to the environment. If these wastes are not
controlled by treatment before discharging or if they are not recycled,
serious pollution problems could arise.
Solid Waste Emissions
Solid wastes are generated in this industry by the nature of
the numerous processes. Slag from the smelting of copper and drosses
from the aluminum industry are examples. Drosses from the treatment
of aqueous wastes generated in the production of electrolytic copper is
another example. Another source of solid wastes common to this and other
industries is the dust collected in control equipment such as baghouses.
Solid wastes such as slurries (mixtures of solids and liquids) and fine
particulate materials are disposed of in lagoons, in landfills, or, in
many cases, become a source of raw material for the secondary industry.
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As with the other wastes from this industry, the composition of
this waste is dependent on the process and processing steps in each
segment. These wastes are known to contain metallic and nonmetallic
materials found also in atmospheric emissions, aqueous wastes, and the
raw materials to this industry. Many of them are toxic.
In summary, this industry generates substantial quantities of
solid wastes. In many cases, serious pollution problems can result if
these wastes are not disposed of in a safe and adequate manner.
RAW MATERIALS
Raw materials for the industry are divided into three broad
categories as follows.
(1) Old Scrap. This is the kind most commonly associated
with the scrap business though not necessarily the
largest in volume. Old scrap is discarded, dismantled,
worn out metallic elements. Typical examples are:
a radiator removed from a wrecked car; copper pipes
taken from an old building; high strength, heat
resistant rotor blades once used in a jet engine,
applicances discarded by homeowners.
(2) New Scrap. This is metal which has never been made
into or used as an end product. It comes from
industrial sources and is the by-product of some
part of the manufacturing process. Common examples
include: a manufacturer of aluminum cans buys huge
coils of sheet aluminum and when the can lids (tops)
are made on stamping (blanking) machines which punch
the lids out of sheets of original material, the
remaining skeleton is scrapped and usually described
as clippings; or, when household faucets are produced
in foundries which make the body of the faucet in a
sand mold to produce a casting; or, when pouring molten
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metal into the mold some will spill over the mold
opening or into the sand rather than into the mold
cavity and these spillings are scrapped because they
pick up impurities or become mixed with dirt and sand.
These are usually called foundry spillings or residues.
This "new" scrap differs from "old" scrap in that
it is generally available in larger and more uniform
lots; and its metallic constituents are more readily
identifiable.
(c) Obsolete Scrap. This category consists of generally new,
unused but technologically obsolete parts, over-runs
from the production process, inventory that is no longer
required, repossessed merchandise or auctioned material.
Some examples: The U. S. Government sells for scrap,
spare parts for a radar network which is no longer
needed for national security; or a railroad has in
stock a type of journal bearing but decides to standardize
its entire fleet of cars with foller bearings, making
the solid bearings available as scrap.
A detailed description of the source of raw materials for each
segment is included in the descriptions which follow.
PRODUCTS
Products from the Secondary Industry are generally ingots of
refined or partially refined metals which are shipped to the fabricator
for processing into a finished product or shipped to the Primary Industry
for further refining. In some cases, the product is consumed as produced
from the process as described in discussions which follow on the products
from each industry segment.
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PROCESS DESCRIPTION OF ALUMINUM SEGMENT OF
SECONDARY NONFERROUS METALS INDUSTRY
Tonnage-wise, the aluminum segment constitutes the second
largest segment of the secondary nonferrous metals industry. Based on
1969 data, U. S. production rate was 1,056,000 tons. Emissions from
this segment include fine particulate matter and gaseous materials which
may become atmospheric pollutants, and aqueous and solid wastes which,
if not properly disposed of, will pollute the water system and the land.
Raw Materials
Sources of raw materials to this segment include both new and
old scrap. The new scrap, that which comes from a fabricator who does
not choose or is not equipped to recycle the scrap, accounts for about
75 percent of the scrap. Old scrap, a product of obsolescence, becomes
available to this segment when consumer products have reached the end of
their economic life and have been discarded, and accounts for approxi-
mately 25 percent of the domestic scrap consumed in the U. S. Basically,
the scrap can be divided into 6 categories: (1) sheet and castings,
(2) new clippings, (3) borings and turnings, (4) high aluminum-iron alloy scrap,
(5) drosses or skimmings with fluxing salts, and (6) drosses or skimmings
without fluxing salts.
The choice of scrap which a secondary smelter purchases for
use in its furnaces is determined by the equipment or flowsheet of the
individual smelter. Obviously, a smelter with no burning or drying
equipment for processing oily borings and turnings cannot use this
material. Likewise, smelters without crushing or residue processing
equipment are similarly restricted in the types of scrap they can
process. Air pollution codes in many cities also have limited the processing
of heavily painted material such as painted siding or Venetian blinds.
Hence, smelters having limited processing equipment must be selective
in scrap purchasing, while more sophisticated smelters have greater latitude
in scrap purchasing.
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C-13
Products
The products from the secondary aluminum segment are:
(1) aluminum alloy castings, (2) aluminum shot, (3) hot metal,
(4) aluminum fines, and (4) hardeners. The aluminum a.lloy castings
may be in the form of ingots (15 to 30 Ib), billets (approximately
1000 Ib), notched bar (2 to 5 Ib), and hardeners of different weights.
"Hot metal" is molten aluminum alloy which is tapped directly from the
furnaces into preheated crucibles with capacities up to 15,000 Ib and
transported directly up to distances of 300-400 miles to the consumer
(foundries). Aluminum shot is small beads of quenched aluminum metal.
Aluminum fines are the undersize (-20 microns) material from screening
of the aluminum scrap treated by the burning/drying process.
Process Description
The recovery of aluminum from scrap normally involves two
manufacturing operations: (1) scrap pretreatment, and (2) smelting-
refining. The two manufacturing operations and the individual processes
under each operation are shown in the attached industry segment flowsheet
entitled "Aluminum Segment of the Secondary Nonferrous Metals Industry".
Scrap Pretreatment
Aluminum scrap is pretreated prior to smelting to remove
contaminants and physically prepare the material for further processing.
Three types of pretreating (mechanical, pyrometallurgical, and hydro-
metallurgical) are used. The pretreatment process employed depends on
the type of scrap. The individual pretreatment processes are indicated
in the flowsheet by numbers 1 through 6.
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014
Shredding/Classifying Process (1). The iron core and
neoprene or plastic insulation is removed from electrical conductor
scrap containing superpure aluminum by the Shredding/Classifying
Process (1). This treated aluminum scrap is used to produce, among other things,
hardeners. The processing steps are: (a) shredding of the scrap into
small pieces to separate the iron core and plastic coating from the
aluminum alloy, (b) magnetically treating to remove the ferrous portion
of the scrap, and (c) separating the neoprene or plastic insulation
from the high-purity aluminum by an air classification system.
Energy demand for this process is that necessary to drive the
equipment.
The Shredding/Classifying Process (1) is a minor source of
atmospheric emissions. However, significant quantities of solid wastes--
ferrous scrap and neoprene or plastic waste—are generated. The scrap is
recycled and plastic waste is disposed of in a landfill.
This process has no serious potential pollution problems of
any kind.
Baling Process (2). Densification or compaction of sheet,
castings, and clippings is achieved by baling in specially designed
baling machines. Baling is normally conducted by the scrap dealer or
at the source of scrap generation. Occasionally, the baled scrap is further
processed by crushing and screening prior to smelting.
Energy demand is limited to that needed to drive the equipment.
Atmospheric emissions from this process are composed of suspended
particulate matter containing primarily dirt from the scrap and alumina
resulting from the oxidation of the aluminum dust. Solid wastes
generated arc scrap iron, magnesium, and other scrap found mixed with
the scrap aluminum.
The quantity of pollutants generated by baling is low;
therefore, the process has a low pollution potential.
Crushing/Screening Process (3). Borings and turnings which
result from machining and drilling are treated by the crushing/screening
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process to density the aluminum values and remove contaminants. This
process entails three process steps: (a) crushing in a hammermill to
densify the scrap, (b) deoil, (c) dry, (d) screening to remove aluminum
fines, and then (e) passing over a magnetic separator to remove the
tramp iron.
Energy demand for this process is that needed to drive the
equipment and oil/gas for the dryer.
The process produces essentially no atmospheric emissions and
no aqueous wastes. The quantity of solid wastes such as tramp iron
generated is expected to be low as the majority of the iron is removed
prior to crushing.
The process has no potential for serious pollution problems.
Burning/Drying Process (4). Borings, turnings, and other organic-
contaminated scrap are, in some cases, smelted without removal of the
organic contaminants and water. However, the scrap is generally treated
to remove the water and organic matter such as machining oils by the
burning/drying process. This process involves several processing steps:
(a) clashing in a hammermill to densify the scrap, (b) heating the
crushed material in a gas-oil fired rotary dryer to remove organic
contaminants and water, (c) screening the dryed material to remove
the aluminum fines which are sold for explosive or pyrotechnic purposes,
and (d) icagne tic ally treating the remainder to remove the tramp iron.
Łnergy demands for this process are; (a) gas or oil to
supply the heat to burn the organic compounds and evaporate water from
the scrap, and (b) that required to drive the equipment.
The burning/drying process is a source of atmospheric emissions
and solid wastes. The atmospheric emissions consist of gaseous products
primarily carbon dioxide from combustion of the fuels and the organic
contaminants, and particulate matter entrained in the gases. The gases
may also contain some chlorides, possibly fluorides and sulfur oxides,
depending on the composition of the organic contaminants. The particulate
matter is parimarily alumina resulting from oxidation of the small
particulates of aluminum swept from the kiln by the combustion gases.
The solid waste is primarily tramp iron removed in the magnetic treatment
of the crushed scrap.
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Thus, the burning/drying process presents serious potential
pollution problems if the emissions are not controlled properly, especially
in those cases where the organic contaminants contain significant
quantities of halides, where significant quantities of alumina are
emitted, and where oil is used in place of gas as the fuel. Normally,
the atmospheric effluent from the Burning/Drying Process is treated
with an afterburner located in the stack. However, wet scrubbers are
beginning to replace the afterburner, in which case the air pollution •
problem can become a water pollution problem. The solid wastes generated
are not a serious pollution problem.
SweatinjL_Pr_Qc_e_sJL _L5_1. The contaminant-iron is removed from
high iron scrap by the sweating process, employing a sloping hearth or
grate-type furnace. The processing steps employed are: (a) heating
the scrap to melt the aluminum and other low melting constituents which
flow by gravity into a collecting pot or ingot mold, and (b) casting
the melt into pigs (30 Ib ingots) or sows (up to 1000 Ib ingots) in air-
cooled molds. The furnace is heated to approximately 1400 F to separate
the low melting aluminum along with other low melting materials from
the scrap.
Energy demand for this process is natural gas and that needed
to drive the equipment.
Emissions from this process are: (a) atmospheric emissions
composed of the combustion products and particulate matter, primarily
aluminum trioxide, and (b) solid wastes containing iron contaminated with
aluminum and other nonferrous elements such as zinc, magnesium, and
lead. Gaseous emissions from the furnace are generally passed through
an afterburner before being emitted to the atmosphere. The solid
wastes are discarded.
The process can cause serious atmospheric pollution problems,
if not properly controlled. According to a survey , raw (uncontrolled)
(1) Duprey, R. L., "Compilation of Air Pollution Emission Factors",
U. S. Dept. HEW, NAPCA, Raleigh, North Carolina, pp 28-29 (1968).
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particulate emission factor from the sweating process is reported to
be 14.5 Ib/ton (7.25 Kg/MT) of metal processed. This factor does not
include gaseous emissions. Composition of the emissions, both gases and
particulate matter, will need to be determined by source testing. A
baghouse is usually used to control dust emissions.
The solid wastes should cause no pollution problems.
Leaching Process (6). Leaching removes the contaminants such
as fluxing salts and other water soluble components from drosses,
skimmings, and slags to produce an aluminum scrap suitable for the
smelter. The processing steps are: (a) wet milling of the scrap in an
attrition mill or a ball mill to densify the scrap, (b) screening to
remove the fines and dissolved salts, (c) drying to remove the water,
and finally (d) treating with a magnetic separator to remove the
ferrous portion.
Energy required is that needed to operate the equipment and
to dry the crushed scrap.
The process produces no atmospheric emissions except possibly
in the drying step. However, significant quantities of water and solid
wastes are produced. The water wastes containing dissolved and suspended
solids are disposed of via a series of settling ponds. The solid wastes
result from the settling pond and the undersize material from the screening
operation.
The process does not present an atmospheric pollution problem;
however, there is a water pollution problem as well as a problem relating
to disposal of the solid wastes. From a recent survey of the secondary
aluminum industry by Battelle, the water pollution problem essentially
can be handled by disposing of the water wastes in settling ponds. The
solid wastes can be placed in a landfill.
Smelting/Refining Operation
Reverberatory (Chlorine) Smelting-Refining Process (7). Alloy
ingots, shot, and hot metal are produced from treated aluminum scrap,
sweated pigs, and, in some cases, untreated scrap by this process.
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The process steps are: (a) charging of the scrap to the
furnace; (b) melting of the scrap; (c) fluxing to remove certain
contaminants; (d) alloying, i.e., the addition of certain metals to
produce a melt of the desired composition; (e) mixing of the melt to
produce a homogeneous material; (f) demagging with gaseous chlorine;
(g) degassing with an inert gas such as nitrogen or nitrogen-chlorine
mixture to remove entrapped hydrogen and other gases; and (h) skimming
to remove the slag or dross containing the impurities. After slag
removal, the melt is (1) poured into molds and cast into alloy ingots,
billets, and notched bars; or (2) poured onto a vibrating feeder and
quenched in water to produce shot; or (3) poured into heated crucibles
and transported to the consumer as "hot metal", i.e., molten metal. Any
given smelter may not incorporate all of these steps into the process,
but may use a combination of the steps.
The reverberatory furnace, a rectangular box usually ranging
in capacity from 15 to 90 tons is used in this process to smelt and
refine the aluminum. The furnace is direct fired; furnace fuel may be
either natural gas or fuel oil. Heat input ranges from 2,000 to 2,500 Btu
per pound of alloy. Additional energy is required to operate the
auxiliary equipment.
Emissions from this process are atmospheric emissions (gases
and particulate matter), aqueous wastes, and solid wastes. In addition
to the combustion products, the gases may contain chlorine, hydrogen
chloride, zinc chloride, magnesium chloride, aluminum chloride, and
aluminum oxide, along with minute quantities of a wide variety of
other metals contained in the scrap and added during the smelting-
refining. Likewise, the aqueous and solid wastes contain a wide variety
of metal values depending on the scrap.
All processing steps are sources of atmospheric emissions.
The addition of scrap to the furnace and melting of the scrap is a
major source of atmospheric emissions depending on the quality of the
scrap. Quantitative data are not available for the secondary aluminum
(2)
segment. However, for the brass and bronze segment, raw emission
(2) "Air Pollution Aspects of Brass and Bronze Smelting and Refining
Industry", U. S. Dept. HEW, NAPCA, Raleigh, North Carolina (1969).
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factors for the charging step are reported to range from 11.7 to 59.0 Ib
of particulate matter per ton of feed. Comparable emission factors may
be expected for the charging step for the secondary aluminum segment,
especially at those smelters charging untreated scrap and scrap containing
•
significant quantity of volatile impurities such as zinc.
Fluxing is practiced to some extent at most secondary aluminum
smelters. Some of the components volatize during the smelting-refining
while others, along with impurities or contaminants in the scrap
aluminum, are entrained in the furnace exit gases. Composition of the
atmospheric emissions will vary depending on the scrap and the flux.
However, these emissions have been found to contain such elements as
sodium, aluminum, magnesium, calcium, iron, lead, manganese, potassium,
chromium, zinc, and nickel, in addition to the combustion gases and
hydrogen halides.
Alloying produces minor amounts of fumes and dust which are
carried from the furnace by entrainment in the combustion gases and
other gases formed during this processing step.
Mixing of the melt to insure uniform composition and to mix
the fluxes into the melt is generally accomplished by injecting nitrogen
gas below the surface of the melt. As a result, mixing becomes a
significant source of atmospheric emissions. The gaseous portion of the
emissions is composed of nitrogen, hydrogen halides, and other volatile
components. Composition of the particulate matter is similar to the
emissions from the fluxing processing step.
Removal of magnesium (demagging) is accomplished by chlori-
nation. This entails lancing the molten aluminum with chlorine gas
which reacts with the aluminum to form aluminum chloride. The aluminum
chloride then reacts with the magnesium to form magnesium chloride which
is carried along with other metallic and nonmetallic impurir-ies and
gaseous contaminants to the surface of the melt. Some of these are
trapped in the flux on the surface of the melt, while the remainder is
volatized and becomes part of the atmospheric emissions.
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The demagging step is a major source of atmospheric emissions
in the secondary aluminum segment. Raw emission factor for this
(2)
processing step is reported^ ' to be 1000 Ib of particulate matter per
ton of chlorine used (500 Kg/t).* Through the use of a baghouse as the
control device (which does not remove the gases), the particulate emissions
factor is reduced to 50 Ib of particulate matter per ton of chlorine used
(25 Kg/t).
In order to remove the gases and the particulate matter, a
wet scrubber using a 10 percent caustic solution as the scrubbing
(4)
medium in series with a baghouse is employed. In one installation,
two of the scrubbers were arranged in parallel. After scrubbing, the
fumes were sent to a five-compartment baghouse for particulate removal.
In this installation, the scrubber removed virtually all of the hydrogen
chloride gas and greater than 90 percent of the chlorine gas. Wet
scrubbing also hydrolyzes and removes the majority of the chlorides such
as aluminum chloride as the corresponding oxides or hydroxides.
Composition of the atmospheric emissions from the demagging
step depends somewhat on the composition of melt and fluxes employed
in the fluxing step. However, in addition to the combustion gases, the
gaseous portion of the atmospheric emissions is composed of chlorine,
hydrogen halides such as hydrogen chloride, along with chlorides of the
volatile metals. The particulate emissions are composed of such metal
values as calcium, copper, magnesium, nickel, zinc, cadmium, and aluminum.
Degassing of the molten aluminum prior to casting is necessary
to remove hydrogen absorbed from the atmosphere or other sources of
moisture or water vapor. The metal is degasified by lancing with dry
nitrogen, chlorine, or mixtures of the two gases. If a smelter does not
have adequate ventilation and air pollution abatement equipment, nitrogen
is used for degassing, because degassing with chlorine or mixtures of
chlorine and nitrogen results in severe fuming. Composition of these
(3) Duprey, F. L., "Compilation of Air Pollution Emission Factors",
U. S. Dept. HEW, NAPCA, Raleigh, North Carolina, pp 28-29 (1968).
(4) Danielson, John A., ed., Air Pollution Engineering Manual, U. S.
Dept. HEW, Cincinnati, Ohio, pp 284-292 (1967).
* Kg/t = kilograms per ton (1000 Kg).
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fumes may vary from smelter to smelter, but, in general, is similar to
those emissions from the demagging processing step.
Skimming to remove the dross or slag collected on the surface
of the melt and casting of the ingots are minor sources of atmospheric
emissions.
Another potential source of atmospheric emissions results
from cooling and from storage of the slag (drosses and skimmings) while
enroute to the processor. If allowed to come in contact with water, the
nitrides and carbides of aluminum react with the water to form hydrocarbons
and ammonia which are liberted to the atmosphere.
Aqueous wastes are generated during ingot and shot cooling or
quenching, and from scrubbing of the emissions from the reverberatory
furnace. Also, if the drosses and skimmings are stored in the open,
runoff water may become a source of aqueous wastes. The waste cooling
water is disposed of by vaporization, discharging directly to a municipal
sanitary sewer or stream, or a pond. In a survey of 50 secondary aluminum
plants, 24 discharged to sewers or streams, 4 discharged to a pond,
13 recycled continuously, 7 discharged after recycle, and 2 vaporized the
water. This wastewater contains significant quantities of heavy metals,
phenol, and other contaminants and is, therefore, a potential source of
water pollution.
The other source of wastewater from the Reverberatory (Chlorine)
Smelting-Refining Process (7) is that from the wet scrubbers. This waste
which may or may not be neutralized is discharged to ponds. That which
has not been neutralized has a pH of about 1.5 and contains hydrolyzed
metal chlorides of aluminum, magnesium, zinc, manganese, cadmium, copper,
nickel, and lead. The neutralized scrubbing liquor with a pH of 9 to 11
contains sodium, potassium, and calcium and lesser quantities of the
heavy metals, aluminum and magnesium.
Solid wastes generated by this process include: (1) drosses
and skimmings from the process itself, and (2) wastes from the air
pollution control equipment. The drosses and skimmings are recycled,
while the others are probably disposed of by routine methods such as
landfill. If not properly prepared, the leachate from the landfill can
enter the ground water and cause pollution problems.
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Thus, the Reverberatory (Chlorine) Smelting-Refining
Process (7) is a major source of atmospheric emissions from the
aluminum segment of the secondary metals industry. These emissions
containing gaseous and fine particulate matter present serious pollution
problems if emitted to the atmosphere. Raw emission factors exclusive
of the demagging processing step for this process have been reported to
be 4.3 Ib of particulate matter per ton (2.15 Kg/t of metal processed.
Using a baghouse or an electrostatic precipitator as the pollution
control device reduced the emission factor to 1.3 Ib of particulate
matter per ton (0.65 Kg/t of metal processed. Raw emission factor
for the demagging processing is reported at 1000 Ib of particulate
matter per ton of chlorine (500 Kg/t) used. The emission factor is
reduced to 50 Ib of particulate matter per ton of chlorine (25 Kg/MT)
used by employing a baghouse as the control device.
Currently, most of the secondary smelters using chlorine in
the demagging processing step employ wet scrubbers alone or in combination
with baghouses to reduce the atmospheric emissions. Although emission
factor data are not available, it is expected that this combination of
pollution abatement equipment will remove the gaseous emissions such as
chlorine and hydrogen chloride as well as the particular matter more
efficiently than either the baghouse or electrostatic precipitator. In
one installation, the scrubber removed virtually all of the hydrogen
chloride gas, greater than 90 percent of the chlorine, and greater than
80 percent of the aluminum chloride.
Particle morphology of the particulate emissions, i.e.,
particle size and shape, is somewhat dependent upon the composition of
the scrap and the processing parameters. However, in general, the
particulate matter is composed of particles ranging in size from a few
hundredths of a micron (approximately 0.05 micron) to several microns
(approximately 2 to 5 microns). In one case, the fume from salt-
cryolite mixtures was found to be composed of particles ranging in size
from less than 2 microns to less than 0.1 micron. In another case the
fume from a demagging operation was found to be composed of a mixture of
particles with 90 to 95 percent less than 1 micron in diameter. This
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small particle size makes it difficult to collect the emissions in
baghouses and electrostatic precipitators.
The emissions are generally composed of particles exhibiting
both regular and irregular particle morphology. The morphology will
range from acicular shapes (long needle shape particles) to spherical
particles.
Solid wastes and aqueous wastes, if not disposed of properly,
can present pollution problems.
Reverberatory (Fluoride) Smelting-Refining Process (8). This
process is essentially the same (i.e., the same processing steps are
employed as in Reverberatory (Chlorine) Smelting-Refining) except that
aluminum fluoride (A1F-) is used in place of gaseous chlorine in the
demagging processing step. In Process 8, the magnesium is removed by
mixing solid A1F, into the molten metal. The A1F3 reacts with the
magnesium to give aluminum metal and magnesium fluoride which floats or
is carried by the mixing gas to the surface of the molten metal and is
removed as part of the dross or skimmings.
Conducting the demagging with A1F.J results in a significant
reduction in the quantity of atmospheric emissions. Consequently, the
problems associated with atmospheric pollution are significantly
reduced, yet not completely eliminated as significant quantities of
atmospheric pollutants are discharged. Instead of large quantities of
chlorine gas, the emissions contain fluorides as gaseous fluorides or
fluoride dusts. If not properly controlled, the fluorides as well as
the other particulate matter and gases in the effluent can cause serious
pollution problems. The atmospheric emissions may be controlled by the
same dry or wet methods used in Process 7.
Aqueous waste generated in this process consists of waste
cooling water generated during ingot and shot formation. This waste
water is disposed of either by discharging to sewers, streams, or ponds;
recycled continuously; recycled partially; or evaporated (see discussion
of waste cooling water under Process 7 as same treatment and disposal
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methods are employed). The wastewater from the fume scrubber (which is
recycled) is first treated with caustic to remove the fluoride. The
solids formed during neutralization are separated in settling tanks and
the effluent is recycled to the scrubber system.
Solid wastes generated by this process are: (1) drosses and
skimmings from the process itself, and (2) solids from the air pollution
control equipment. The dross and skimmings are recycled. Solid waste
(sludge) from the wet scrubber is dewatered and placed in a landfill.
If not properly prepared, the leachate from the landfill can enter the
underground water system and cause pollution problems. Those smelters
using the dry collection system also dispose of the fume dust and bag
coating substances in landfills. Although the fluorides are considered
to be insoluble, the solubility may be great enough to contaminate
ground water.
Because of the toxic and hazardous nature of the pollutants
generated by this process, the process presents serious pollution
problems if these pollutants are not collected and disposed of in a
proper manner.
Crucible Smelting-Refining Process (9). For producing small
quantities of aluminum alloy castings, i.e., up to approximately 1000 Ib,
the Crucible Smelting-Refining Process (9) is used. The processing
steps are: (a) charging of the melt to the furnace, (b) melting of
the charge, (c) fluxing to remove the contaminants if necessary,
(d) alloying to produce a melt of the desired composition, (e) mixing
to homogenize the molten metal, (f) demagging, (g) degassing, and
(h) skimming. Afterwards, the melt is poured and cast into the desired
shapes. Any given smelter may not incorporate all of these steps into
the process, but may use a combination of the steps depending on the
source of scrap.
Energy demand is limited to that required to operate the
equipment and to heat the furnace. The furnace is heated indirectly
with,gas or fuel oil as the source of fuel. However, electricity may
also be used as the source of energy.
-------
C-25
Potential environmental pollutants from this process are:
atmospheric emissions which are composed of gases and particulate matter,
aqueous wastes containing dissolved and suspended solids and solid wastes.
Since this process is quite similar to reverberatory smelting-refining
except for the size of operation, see discussions in the previous sections
on Processes 7 and 8 for data on composition of pollutants, processing
steps generating the wastes, and disposal of the pollutants.
This process has the potential for generating significant
pollution problems.
Induction Smelting-Refining (10). This process produces
hardeners, alloys of known composition, which are used to introduce
precise amounts of particular metals into a melt to meet predetermined
specifications. The most common hardening agents are titanium, boron,
and chromium. The hardeners are produced by melting and blending
electrical conductor scrap (superpure aluminum) with the hardening agent
in an induction furnace. The processing steps are: (a) charging of the
scrap to the furnace, (b) melting of the scrap, (c) blending the molten
metal with the alloying agent, (d) skimming of the melt to remove the
oxides on the surface, (e) pouring of the melt, and (f) casting into
notched bars.
Energy demand is limited to that needed to run the equipment
and the electricity to melt the scrap.
The process produces small quantities of atmospheric emissions
and aqueous and solid wastes. The atmospheric emissions contain, in
addition to aluminum, small amounts of the alloying agent and other
metals found in the scrap. These emissions are generated in all of the
processing steps. The aqueous wastes are generated during the casting
of the notched bars, whereas the solid wastes are drosses (skimmings
from the surface of the melt). These wastes can be collected and
disposed of by the methods employed in Process 7.
This process has a low potential for the production
pollutants.
-------
C-26
Rotary Furnace Smeltinp-Refining (II). This process is employed to
recover the aluminum values from such raw materials as drosses to produce
high aluminum ingots which are refined in the reverberatory furnace.
The processing steps are: (a) charging of the scrap and flux, (b) melting
of the charge, (c) pouring, and (d) casting of the ingots.
The energy demand for this process is that needed to drive the
equipment and natural gas or fuel oil to heat and melt the charge.
The process produces atmospheric emissions composed of gases
such as the combustion products, entrained air, and volatile metal values
and particulate matter such as the flux and particles of the charge.
Solid wastes are the slag containing impurities extracted from the
aluminum and the sludge from the wet scrubber. Aqueous waste consists
of primarily the cooling water used in casting the ingots. These wastes
may be disposed of by methods used for disposal of similar wastes from
other processes.
The process can cause serious pollution problems, if not
properly controlled.
-------
C-27
Population of Secondary Aluminum Processors
(1) Alloys and Chemicals Corporation
4365 Bradley Road SW
Cleveland, Ohio 44109
Telephone: (216) 661-8600
(2) Aluminum Billets, Inc.
3786 Oakwood Avenue
Youngs town, Ohio
Telephone: 792-6511
(3) Aluminum & Magnesium
Tncorporated
Huron and W. Monroe Streets
Sandusky, Ohio
(4) Aluminum Smelters Incorporated
322 Legion Avenue
New Allen, Connecticut
(5) Aluminum Smelting and Refining
Company, Inc.
5463 Dunham Road
Maple Heights, Ohio 44137
Telephone: 662-3100
(6) Apex Smelting Company
Division of Amax Aluminum Company
2515 West Taylor Street
Chicago, Illinois
Telephone: (312) 332-2214
(7) Aurora Refining Company
Box 88
Aurora, Illinois
(8) Barnum Smelting Company
Barnum Avenue
Bridgeport, Connecticut 06608
(11) Joseph Behr and Sons, Inc.
1100 Seminary Street
Rockford, Illinois
Telephone: (815) 962-7721
(12) Belmont Smelting & Refining
Works, Inc.
320 Belmont Avenue
Brooklyn, New York 11207
Telephone: DI2-4900
(13) W. J. Bullock, Inc.
Post Office Box 539
Fairfield, Alabama 35064
(14)
(15)
(16)
(17)
(9) Batchelder-Blasius, Inc.
Post Office Box 5503
Spartanburg, South Carolina
(10) Bay Billets Inc.
1364 Olds Street
Sandusky, Ohio
(18)
(19)
29301
(20)
Colonial Metals .Company
Columbia, Pennsylvania
Telephone: (717) 684-2311
J. R. Elkins, Inc.
518 Gardner Avenue
Brooklyn, New York
11222
Excel Smelting Corporation
1300 North Seventh Street
Memphis, Tennessee 38107
Federated Metals
Division of American Smelting
and Refining Company
12 Pine Street
New York, New York
Firth Sterling, Inc.
3113 Forbes Avenue
Pittsburgh, Pennsylvania
15230
General Smelting Company
Division of Wabash Smelting
Incorporated
2901 EW Moreland Street
Philadelphia, Pennsylvania
Telephone: GA3-3200
Gettysburg Foundries
Post Office Box 421
Gettysburg, Pennsylvania
17325
Telephone: 334-5616
-------
C-28
(21) Hall Aluminum Company
1751 State Street
Chicago Heights, Illinois
(22) Harco Aluminum, Inc.
4528 West
Chicago, Illinois 60651
(23) Henning Brothers & Smith, Inc.
91-115 Scott Avenue
Brooklyn, New York
(24) Holtzman Metal Company
5223 McKissock Avenue
St. Louis, Missouri 63147
(25) North American Smelting Company
Post Office Box 1952
Marine Terminal
Wilmington, Delaware
Telephone: OL4-9901
(26) Northwestern Metal Company
North 27th Street
Lincoln, Nebraska
(27) Paragon Smelting Corporation
36-08 Review Avenue
Long Island City, New York 11101
Telephone: (212) RA9-3641
(28) Pioneer Aluminum, Incorporated
3800 East 26th Street
Los Angeles, California
(29) George Sail Metals Company, Inc.
2255 East Butler Street
Philadelphia, Pennsylvania 19137
Telephone: (215) PI3-3900
(30) Silberline Manufacturing Company,
Inc.
Lansford, Pennsylvania
Telephone: (717) 645-3161
(31) Sonken-Galamba Corporation
Second and Riverview Streets
Kansas City, Kansas 66118
Telephone: (913) MA1-4100
(32) Superior Industries, Inc.
3790 Oakwood Avenue
Youngstown, Ohio 44509
(33) U. S. Aluminum Corporation
of Pennsylvania
Railroad and Biddle Streets
Marietta, Pennsylvania
Telephone: 426-7811
(34) U. S. Reduction Company
Box 30
East Chicago, Indiana
Telephone: RE1-1000
(35) Wabash Smelting, Inc.
Post Office Box 453
Wabash, Indiana 46992
-------
SCRAP PRETREATMENT
BELTING/REFINING
MECHANICAL
SHtn.
CASTINGS, CLIPPINGS
ELECTRICAL cowouCTofls -
_ UNTREATED I
. SCRAP '
S »CATED
PIC/SOW
HTQROMETALLURGICAL
DROSSES.SKIMMINGS.
SLACS
r AUOTIN6 AGCNF
• -NITROGEN
I —CHLORINE
1 , —ruEi
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LEGEND
O ATMOSPHERIC EMISSICMS
A LIOUIO WASTES
O SCH.ID WASTES
SCCONDMT WW
MATERIALS fW USE •» OTHCB
nousrnict
INTCRMCOUIC maoucT
SIGNATURE DIV DATE
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BATTCLLC MEMORIAL INSTiniTe
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-------
C-30
PROCESS DESCRIPTION OF THE ANTIMONY SEGMENT OF
THE SECONDARY NONFERROUS METALS INDUSTRY
The secondary antimony segment recovers antimony as an alloy
with lead rather than as pure metal because of the far greater demand
for the alloy. Also, primary lead refineries recover the metal as
antimonial lead. The bulk of the antimonial lead is used in storage
battery grids and contains about 3 percent antimony.
Statistics for the secondary antimony industry for 1971 are
presented below.
Kind of Scrap
New scrap
Old scrap
Total scrap
Production,
Short Tons
3,342
17,575
20,917
Form of Recovery
An antimonial lead
In other lead alloys
Total recovery
Production,
Short Tons
15,839 .
5,078*
20,917
* Includes 11 short tons in tin-base alloys.
Further, in 1971, by-product antimonial lead produced at primary lead
refineries amounted to 19,686 tons containing 1,191 tons of antimony
(6 percent).
Raw Materials
New scrap consisting of residues and drosses resulting from
manufacturing and casting amounted to 16 percent of the total scrap
processed in 1971. Old scrap, obtained mostly from used lead-acid type
battery grids, amounted to the remaining 84 percent. Greater than 99 percent
of both old and new scrap was in the form of lead-base alloys while less
than 1 percent was comprised in tin-base alloys.
Although the increased useful life of batteries tended to reduce
the quantity of available battery scrap, the trend was soon counter-
balanced by the increase in the automobile population, thus insuring a
-------
C-31
continued supply of used battery grids as scrap. The raw materials to
this industry, therefore, include:
(1) Old battery grids
(2) Residue and drosses from manufacturing and casting
(3) Scrap from the machining and manufacturing industry.
Products
Products from the antimony segment include:
(1) Antimonial lead alloys used in storage battery
grids containing about 3 to A percent antimony (grid metal)
(2) Body solder used in automobile bodies
(3) Type metal used in printing. This alloy has
4-23 percent antimony, 17-30 percent tin, and the
remaining is lead
(4) Master alloys containing large amounts of antimony
(15 percent or more) and used in blending to
manufacture other alloys
(5) Pure lead as a by-product.
Process Description
The recovery of antimony as alloy from scrap involves three
manufacturing operations: (1) scrap pretreatment, (2) smelting, and
(3) refining/casting. These operations and the major individual processes
under each operation are shown on the flowsheet of this segment of the
secondary nonferrous metals industry.
Scrap Pretreatment Operation
New scrap generated in machine shops is not pretreated. Old
scrap from type and babbit metals is not only insignificant in quantity,
but is generally not pretreated before smelting. However, since 70 percent
of the old scrap is used battery scrap, pretreatment of these used batteries
-------
C-32
will be described. The flowsheet indicates a single scrap pretreatment
process which is discussed below.
Battery Breaking, Crushing, and Hydroseparation Process (1).
This process which separates the metallic parts of the old. battery from
the plastic and rubber portions is conducted in one of two ways. The more
common method, adopted by about 75 percent of the industry, consists of
the following steps: (a) mechanical sawing of the top of the battery,
(b) manually separating the bottom case from the acid and grids by
dumping, (c) cleaning grids by water spray, (d) crushing the battery tops
and separating the metals on a vibratory table, (e) crushing the bottom
case in a hammer mill for disposal in landfills, and (f) neutralizing
the acid effluent from dump tanks with lime in a settling pond.
The second method, used in about 25 percent of the industry,
consists of the following process steps: (a) crush the whole battery (as
received) in a hammer mill, (b) drain and treat the acid, and (c) conduct
heavy media separation to separate plastics from the lead oxide and lead
metal. This process produces a richer feed to smelters.
Energy requirements for this process are electrical energy
for the vibratory feeder, the hammer mill, and the heavy media separation
column.
The wastes generated are about the same in both processes and
consist of: (J) acidified (sulfuric) wastewater, (2) shredded plastic and
rubber, and (3) fine particles of metal and plastics as ambient air
emissions from the hammer mill and vibrating table.
The potential for pollution from these wastes is greatly reduced
by the following waste treatment processes in current use: (1) neutralization
of acid wastewater with dolomitic lime (CaO) in a settling pond and
(2) landfilling or utilization of shredded plastics in road surfacing
and to produce nonleaching landfill material. As a result of these
waste treatment steps, this process does not have much pollution potential.
If the treatment steps are not adopted, the pollution can be serious.
(1) John A. Bitler and L. John Minnick, "Lime-Sulfur Dioxide Scrubbing
System and Technology for Utilization of Underflow Sludge",
Industrial Wastes, March/April 1973.
-------
C-33
Smelting Operation
This operation consists of two processes which are described
below.
Reverberatory Smelting Process (2). This process melts,
purifies, and separates the metallic portions of the feed scrap generated
in the pretreatment steps. The process steps are: (a) charging the
furnace, (b) melting the charge, (c) pouring out the lead metal, and
(d) removing the slag.
Energy required is from the fuel oil to operate the furnace and
from electricity to operate the auxiliary equipment.
Wastes from the process are atmospheric emissions containing
flue dust and sulfur oxides and liquid wastes.
These wastes are treated effectively. The flue dust has
sufficient lead metal value to warrant almost complete recovery for which
purpose a baghouse is used.' The collected dust is recycled to the furnace.
The sulfur oxides are scrubbed with dolomitic lime and the resulting
sludge (calcium-magnesium sulfates) is used in road surfacing or in
preparing nonleachable landfill material.
The pollution potential of this process can be serious if the
pollution control systems are not properly maintained.
Blast Furnace Smelting Process (3). The blast furnace produces
lead metal with a high antimony content and also reduces the oxides of
lead and antimony to their respective metals. The feed to this furnace
includes slag from the reverberatory furnace.
The process steps are: (a) continuous charging of coke, slag,
and treated battery scrap; (b) heating with blasts of air, and (c) with-
drawing the metal and slag.
Heat energy in the form of coke is the main requirement of the
process.
The wastes produced are: atmospheric emissions containing flue
dust and flue gas rich in sulfur oxides, solid waste as blast furnace slag,
and liquid waste as waste cooling water.
-------
C-34
The atmospheric emissions are treated by the same method used
for emissions from the reverberator/ smelting process. The slag is
probably disposed of in a landfill.
The process has the potential for producing serious pollution
problems if the emissions are not controlled and if collected wastes are
not disposed of in a nonpolluting manner.
Refining and Casting Operation
Pot Molding and Casting Process (4). In this process, the metal
products from the reverberatory and blast furnaces are molded after
adjusting to required alloy compositions. Air blowing is done if removal
of all antimony is desired.
The process steps are: (a) charging the furnace, (b) melting
the charge, (c) blowing if necessary, (d) pouring the molten metal into
the molds, and (e) casting the metal into ingots.
Heat energy is the main requirement.
The wastes are mainly atmospheric emissions containing gases and
metal oxides, dust, and fume. An afterburner burns incinerable fumes and
a baghouse collects the dust and the metal oxides. Finally, the scrubber
takes out acidic oxides before the off gases are vented to the atmosphere.
Due to current flue gas treatment employed, the process has
little pollution potential. However, if not controlled, the process could
be a source of pollution problems.
-------
C-35
Population of Secondary Antimony Processors
(1) Allie Smelting Corporation
5116 W. Lincoln Avenue
Milwaukee, Wisconsin 53219
Telephone: (414) 541-7830
(2) Dixie Lead Company, Inc.
Post Office Box 8625
Dallas, Texas 75216
Telephone: WA6-2132
(3) Electric Storage and Battery Company
2 Penn Central Plaza
Phildelphia, Pennsylvania
(4) Florida Smelting Company
2640 Capitola Street
Jacksonville, Florida
Telephone: (904) 353-4317
(5) Frankel Company, Inc.
19300 Filer Avenue
Detroit, Michigan
Telephone: S06-5300
(6) General Battery Corporation
Post Office Box 1262
Reading, Pennsylvania
(7) Inland Metals and Refining Company
651 E. 119th Street
Chicago, Illinois 60628
Telephone: (312) 928-6767
(8) Seitzinger's, Inc.
900 Ashby Street NW
Atlanta, Georgia 30301
Telephone: (404) 876-3787
(9) U.S.S. Lead Refinery, Inc.
5300 Kennedy Avenue
East Chicago, Indiana
Telephone: (219) 397-1012
(10) Hyman Veiner & Sons
Post Office Box 573
Richmond, Virginia 23205
Telephone: (703) 648-6563
-------
BEVI1IONS
SCRAP PRETREATMENT
SMELTING
REFINING/CASTING
OLD SIOBACE
e»TTEBJCS ~
WATER
LIME
LEGEND
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QR SEGOOAttY RAW
MATERIALS FOR USE UuOTtCR
INDUSTRIES
IMTTCLLC MCMOAIAL INfTITUTC
CCT.i»«»m uwofMTonci
KING AVC.. COLUMBUS. OHIO 41301
1~HE SECCfJCARY NONFERROUS
VtETALS INDUSTRY
79986
n
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-------
C-37
PROCESS DESCRIPTION OF THE BERYLLIUM SEGMENT
OF THE SECONDARY NONFERROUS METALS INDUSTRY
Beryllium, like indium, is a very expensive metal with a
current market value of about $6 per ounce. Total U. S. production of
beryllium can be estimated at less than 500 tons per year. Exact
production figures are a trade secret and no data on secondary production
are available. In fact, there is no distinct secondary segment because
most of the scrap is generated in-house.
Raw Materials
Details of raw materials to this industry are not available.
Tonnagewise, the raw material availability is estimated at less than
100 tons per year.
Products
Pure beryllium metal and alloys of beryllium with copper are
some of the products.
Process Description
There are only two beryllium processors in the U. S. They are
not willing to reveal the process steps because of the competitive nature
of the industry and the need to protect the proprietary nature of their
process.
Also, a discussion of the process will not be of much avail
because both the processors feel that it would not be in their best interest
to obtain R&D assistance from external agencies, either public or private.
The companies conduct their research in-house.
The following information provided by one of the companies is
reported for record.
-------
C-38
(1) Scrap beryllium is treated by pyrometallurgical methods
to produce pure metal. Typically, vacuum casting
followed by hot pressing and grinding are used.
(2) Excellent hooding and bag fillers where necessary are
used to prevent escape of beryllium.
(3) Beryllium inhalation produces effects akin to
silicosis and, therefore, extreme care is taken to
minimize the indoor and ambient concentration of
this metal.
(4) The company has no problems that they cannot solve by
their own efforts.
Population of Secondary Beryllium Processors
(1) Brush Wellman Engineered Materials
17876 St. Clair Avenue
Cleveland, Ohio 44110
Telephone: (216) 486-4200
(2) Kawecki Berylco Industries, Inc.
220 East 42nd Street
New York, New York 10017
Telephone: (212) 682-7143
-------
C-39
PROCESS DESCRIPTION OF THE BRASS AND BRONZE
SEGMENT OF THE SECONDARY NONFERROUS METALS INDUSTRY
Introduction
The brass and bronze segment constitutes a large portion of
the secondary nonferrous metals industry.. Since World War II, the
production of brass and bronze ingots in the United States has been
fairly constant, averaging slightly over 300,000 tons annually. In
1969, the production rate was 326,000 tons. Potential environmental
pollutants from this industry are atmospheric emissions, both gases and
particulate matter, liquid wastes, and solid wastes, which if not
controlled and properly disposed of can result in serious pollution
problems. .Emission potential of particulates alone has been estimated
at 10,000 tons annually, based on an annual production of 300,000 tons
of ingots.
Raw Materials
Obsolete domestic and industrial copper-bearing scrap is the
basic raw material of the brass and bronze segment. About two-thirds
of the scrap is in the form of brasses and bronzes; the other one-third
is received in the form of copper scrap. Of the many hundreds of
copper-base alloys that become available for reuse through scrap recovery
channels, 54 primary types of copper-bearing scrap are now included in
the standards published by the National Association of Secondary Materials
Industries. These are listed in Table 1.
Scrap as received is frequently not clean and may contain any
number of undesirable metallic and nonmetallic impurities that contribute
nothing to the composition of the ingot but increase the problems in
producing high quality products. Among these undesirable constituents
are oil, grease, paint, insulation, rubber, and antifreeze.
(1) Bulletin NF-66, National Association of Secondary Materials Industry,
330 Madison Avenue, New York, New York.
-------
C-40
TABLE C-l. TYPES OF COPPER-BEARING SCRAP
No.
Designation
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22-
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
33.
34.
35.
38.
37.
38.
39.
40.
41.
42.
43.
44.
45.
46.
47.
48.
49.
50.
51.
52.
53.
54.
No. 1 copper wire
No. 2 copper wire
No. 1 heavy copper
Mixed heavy copper
Light copper
Composition or red brass
Red brass composition turnings
Genuine babbitt-lined brass bushings • »*-.
High-grade, low-lead bronze solids
Bronze paperraill wire cloth
High-lead bronze solids and borings
Machinery or hard red brass solids
Unlined standard red car boxes (clean journals)
Lined standard red car boxes (lined journals)
Cocks and faucets
Mixed brass screens
Yellow brass scrap
Yellow brass castings
Old rolled brass
New brass clippings
Brass shell cases without primers
Brass shell cases with primers
Brass small arms and rifle shells, clean fired
Brass small arms and rifle shells, clean muffled (popped)
Yellow brass primer
Brass pipe
Yellow brass rod turnings
Yellow brass rod ends
Yellow brass turnings
Mixed unsweated auto radiators
Admiralty brass condenser tubes
Aluminum brass condenser tubes
Muntz metal tubes
Plated rolled brass
Manganese bronze solids
New cupro-nickel clippings and solids
Old cupro-mckel solids
Soldered cupro-nickel solids
Cupro-nickel turnings and borings
Miscellaneous nickel copper and nickel-copper-iron scrap
New monel clippings and solids
Monel rods and forgings
Old monel sheet and solids
Soldered monel sheet and solids
Soldered monel wire, screen, and cloth
New monel wire, screen, and cloth
Monel castings
Monel turnings and borings
Mixed nickel silver clippings
New nickel silver clippings and solids
New segregated nickel silver clippings
Old nickel silver
Nickel silver castings
Nickel silver turnings
-------
C-A1
Products
The products from the brass and bronze segment of the secondary
nonferrous metals industry are hardeners and brass and bronze alloy ingots.
Brass and bronze are copper-base alloys with zinc and tin, respectively, as
the largest secondary component. Other alloy agents may include such elements
as lead, iron, aluminum, nickel, silicon, or manganese. Members of the
Brass and Bronze Ingot Institute produce 31 standard copper-base alloys
as shown in Table 2.
TABLE C-2. NOMINAL CHEMICAL SPECIFICATIONS
FOR BBII STANDARD ALLOYS
Alloy
No. Classification
1A Tin bronze
IB Tin bronze
2A Leaded tin bronze
2B Leaded tin bronze
2C Leaded tin bronze
3A High-lead tin bronze
3B High-lead tin bronze
3C High-lead tin bronze
3D High-lead tin bronze
3E High-lead tin bronze
4A Leaded red brass
4B Leaded red brass
5A Leaded semi-red brass
SB Leaded semi-red brass
6A Leaded yellow brass
SB Leaded yellow brass
6C Leaded yellow brass -
7A Manganese bronze
8A Hi-strength mang. bronze
SB Hi-strength mang. bronze
8C Hi-strength nang. bronze
9A Aluminum bronze
98 Aluminum bronze
9C Aluminum bronze
9D Aluminum bro:ize
IDA Leaded nickel brass
10B Leaded nickel brass
HA Leaded nickel bronze
11 B Leaded nickel bronze
ISA Silicon bronze
12B Silicon brass
Cu, %
86.0
88.0
88.0
87.0
87.0
80-0
83-0
85.0
78.0
71.0
85.0
83.0
81.0
76.0
72.0
67.0
61.0
59.0
57.5
64.0
64.0
88.0
89.0
85.0
81.0
57.0
60-0
64.0
66.5
88.0
82.0
Sn.%
10-0
8.0
8.0
8.0
10.0
10.0
7.0
5.0
7.0
5.0
5.0
4.0
3.0
2.5
1.0
1.0
1.0
1.0
2.0
3-0
4.0
5.0
Pb,%
1.5
1.0
1.0
10.0
7.0
9.0
15.0
24.0
5.0
6.0
7.0
6.5
3.0
3.0
1.0
1.0
9.0
5.0
4.0
1.5
Zn.%
2.0
4.0
4.0
4.0
2.0
3.0
1.0
5.0
7.0
9.0
15.0
24.0
29.0
37.0
37.0
39.0
24.0
24-0
20.0
16.0
8.0
2.0
6.0
14.0
Fe.%
1.0
1.0
3.0
3-0
3.0
1.0
4.0
4.0
1.5
Al.%
0.6
1.0
5-0
5.0
9.0
10.0
11.0
11.0
Ni.-H,
2.0
4.0
12.0
16.0
20.0
25.0
Si.%
4.0
4.0
Mn.%
0.5
1.5
3.6
3.5
0.5
3.0
1-5
-------
C-42
Process Description
The production of brass and bronze products using scrap as
the basic source of raw material entails two manufacturing operations:
(1) scrap pretreatment and (2) smelting-refining. The two manufacturing
operations and the individual processes under each operation are shown
in the attached flowsheet entitled "Brass and Bronze Segment of the
Secondary Nonferrous Metals Industry".
Scrap-Pretreatment Operation
Before the scrap is blended in a furnace to produce the alloy
of a desired composition, removal of some of the metallic and nonmetallic
impurities or contaminants and densification of the scrap are conducted
to produce a material more suitable for subsequent smelting-refining.
The pretreatment process employed depends upon the type of scrap as
noted in the flowsheet by Numbers 1 through 9.
Stripping Process (1). Insulation is removed from electrical
conductors such as cables by specially designed stripping machines or
by hand.
Energy demand is that needed to drive the equipment.
Essentially no atmospheric emissions or liquid wastes are
generated by this process. However, significant quantities of solid
wastes are produced. These wastes consist of primarily organic materials
such as plastics and other materials used as protective coverings on
copper scrap .
The pollutants generated are expected to cause no atmospheric
pollution problems, unless the solid wastes are disposed of by burning.
Disposal of the solid wastes in landfills may possibly cause water
pollution if the landfill is not properly prepared.
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C-43
Briquetting Process (2). Compressing the bulky scrap such
as borings, turnings, and wire into small bales densities the scrap,
permits more compact storage, and makes for easier handling and faster
melting. Briquetting is carried out by compacting the scrap with
hydraulic presses.
Energy required is that to drive the equipment.
Essentially no atmospheric emissions and no liquid or solid
wastes are generated.
The process has little or no potential for the production of
pollution problems.
Shredding Process (3). The shredding process also
achieves separation of the insulation from the copper-bearing scrap.
The process steps are: (a) introducing the insulated copper scrap
such as copper wire into a hammermill where the scrap is cut into small
pieces and the insulation is broken loose from the metal, and (b) removing
the insulation by air classification. This process is used in larger
plants because of high capital costs.
Energy demand is that required to drive the equipment.
Potential environmental pollutants from this process are
atmospheric emissions (gases and particulate matter) and solid wastes.
The atmospheric emissions are the fine particulate matter composed of
the insu1 ":ion and fine metal particles and the gas, generally air, used
in the clarification. The air is not a pollutant; however, the par-
ticulate matter is a potential pollutant if not collected and disposed
of properly. Cyclones are used as the pollution abatement device. Solid
wastes are the insulation and metal particles removed from the scrap
by the air classification.
The process has the potential for creating environmental
pollution problems. The fine particulates may cause atmospheric
pollution problems; the solid wastes may cause water pollution problems
if not disposed of in an approved landfill.
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C-44
Magnetizing Process (4). The scrap may be a mixture of
ferrous as well as nonferrous components. The ferrous component of
the scrap is removed by the magnetizing process which entails passing
the scrap over magnetized pulleys. Scrap treated in this manner is
brass borings and small items.
Energy required is limited to that to drive the equipment.
The only wastes generated by this process are solid wastes--
scrap iron which may be contaminated with other metals and organic
compounds such as the machining oils. These are disposed of by either
landfill or selling to a ferrous scrap dealer.
The process has essentially no potential for the production
of a pollution problem.
Sweating Process (5). Much of the scrap such as radiators
contains low melting components such as lead, solder, and babbitt metal.
These are removed from the scrap by the sweating process which entails
heating the scrap in a furnace. The process steps are: (a) charging
the furnace, (b) melting the low-melting components, (c) collecting
the melt, and (d) removing the treated scrap from the furnace for
further processing. The collected metal may be made into white alloys,
used for lead and tin addition to the copper base alloys, or sold as
produced to a refinery.
Energy required includes the fuel to fire the furnace and
electricity to drive the equipment. Several types of furnaces — rotary
kiln, tunnel furnace, pot furnace, or reverberatory furnace--may be
used. Both gas and oil are potential sources of fuel, depending on
the availability and type of furnace.
Environmental pollutants generated by this process are:
atmospheric emissions, solid wastes, and possibly aqueous wastes.
Atmospheric emissions contain primarily fumes and combustion products
of antifreeze residues, soldering salts, hose connections, and fuel.
Metal content of the emissions is expected to be low because of the low
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C-45
sweating temperature. Solid wastes are those from the pollution
abatement equipment. If wet scrubbers are used to reduce atmosphere
(2)
pollution, liquid wastes are generated.
The process is a potential source of serious atmospheric
pollution and presents potential pollution problems resulting from
disposal of the solid wastes and liquid wastes, if generated.
Burning Process (6^. Much of the scrap is covered with
insulation such as polyethylene, polypropylene, or polyvinyl chloride.
These contaminants are removed from the scrap by the burning process
using such furnaces as muffles and rotary kilns. The process steps
are: (a) charging the furnace, and (b) burning off the organic con-
taminants. Whereupon, the pretreated scrap is removed from the furnace
for further processing.
Energy required is the fuel--gas or oil--to heat the furnaces
and electricity to drive the equipment.
The burning process is a potential source of serious
pollution problems. Burning of the organic contaminants in the scrap
results in atmospheric pollution problems. In addition to the combustion
products such as carbon dioxide and water, the emissions may contain
such gases as ..-ithalic anhydride and hydrogen chloride from the burning
of, for example, polyvinyl chloride. Fluorocarbon insulation releases
hydrogen fli ..ride when burned. Many of these gases are highly toxic
and corrosive.
Little information is available on these emissions. Source
tests in Los Angeles indicate that uncontrolled emissions can be dense
black smoke containing particulate matter in concentrations as large as
29 grains/scf at 12 percent carbon dioxide. These particulates must
have been primarily carbon, because burning the emissions at 2000 F
(2) Schwartz, H. E., Kramer, H., and Company, Controlling Atmospheric
Contaminants in the Smelting and Refining of Copper-Base Alloys,
J. APCA, V5 Ml, May, 1955.
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C-46
(probably in an afterburner) reduced the particulate matter level to
0.16 grains/scf at 12 percent carbon dioxide. '
Solid and liquid wastes are not generated by the process;
however, both may be generated by the pollution control devices.
Disposal of these materials is probably by landfill and settling ponds,
respectively.
Drying Process (7). Borings, turnings, and chips from
machining are covered with cutting fluids, oils, and greases. These
contaminants are removed in the drying process, where the scrap is
heated in, for example, a rotary kiln to vaporize the contaminants.
Energy required is the fuel to heat the furnace and drive the
equipment. Fuel used in this case may be oil or gas.
Drying results in the evolution of considerable quantities
of hydrocarbons depending on the amount present in the scrap. In
addition, the oils, greases, and cutting fluids contain sulfonated
and chlorinated hydrocarbons. Therefore, the gaseous emissions are
composed of sulfur oxides, hydrogen chloride, hydrocarbons, and other
combustion products. Particulate matter in the atmospheric emissions
is soot and possible metallic fumes. Essentially no solid or liquid
wastes are generated by the process.
The atmospheric emissions are controlled by burning the
vaporized fumes in afterburners to oxidize the hydrocarbons to carbon
dioxide and water. However, this technique does not remove the sulfur
oxides and chloride emissions. Wet scrubbing is required.
This process can present atmospheric pollution problems, if
the emissions are not controlled.
Cupolaing Process (8). This process densities bulky scrap
and recovers metal values from slags, skimmings, and other low copper
scrap to produce cupola melt (black copper) which is refined to produce
the finished alloy. The process steps are: (a) charging of the
<3> Air Pollution Engineering Manual. Air Pollution Control District,
County of Los Angeles, Public Health Service Publication
No. 999-AP-40, pp 270-284, 1967.
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C-47
cupola, (b) melting the charge, and (c) removing the slag. Afterwards,
the cupola melt is poured and cast. The charge is made up of coke, flux,
and the copper-containing scrap. Air is introduced through tuyeres
around the bottom of the shaft. Coke is used both as a fuel and as a
reducing agent. Limestone or other materials is used for fluxing. Slag
and concentrated alloy (cupola melt) are tapped near the bottom of the
furnace.
Energy required for this process is coke which is used both
as a fuel and as a reducing agent.
The process produces: (a) atmospheric emissions containing
both gases and particulate matter (fume and dust), (b) liquid wastes,
and (c) solid wastes. The composition of the particulate matter and
gases from the cupola are variable because of the wide variety of scrap,
slag, and skimmings added as the source of alloy and the various fluxes
used. However, it is expected that the particulate matter will contain
such metal values as zinc, lead, tin, copper, silicon, manganese, and
some unburned coke, with the majority of the emissions being zinc because
of its high vapor pressure at the cupolaing temperatures. The gases are
expected to contain, in addition to the combustion products, such materials
as sulfur oxides and halides.
Emission rates also vary because of the wide variation in
the charge composition. For example, raw emission factors (furnace
emission factors) were reported to range from 16.7 to 73.2 Ib of
particulate matter per ton of feed. Using a baghouse with a collection
efficiency of 96.4 percent as the pollution control device, emission
(4)
factors were reduced to within 0.9 to 4.1 Ib of dust per ton of feed.
Since zinc oxide is normally the major component in the fume,
particle shape is generally acicular, i.e., long needles with a large
length to width ratio (~5 to 1). This shape is characteristic of
zinc oxide. In some cases, the particle resembles a wheel with the
rim removed. Particle size ranges from 0.03 to 0.3 micron which makes
(4) Air Pollution Aspects of Brass and Bronze Smelting Refining
Industry, U. S. Dept. HEW, NAPCA, Publication No. AP-58,
Raleigh, North Carolina (1969).
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C-48
collection very difficult. The dust particles have an irregular shape
and are expected to be much larger, possibly in the 5 to 10 micron
range.^ '
Liquid wastes are generated primarily as cooling wastewater
from water-quenching of the slag and from cooling of the cupola. Solid
wastes generated by this process are slags, fumes and dusts collected
in the baghouse, spills, and sweepings. The wastewater is disposed of
in settling ponds, recycled, or sent to sewers or nearby streams. Some
of the solid wastes are recycled; others are discarded.
Atmospheric emissions and liquid and solid wastes generated
by the cupola can result in serious pollution problems.
Gravity Concentration Process (9). Metallic values are
recovered from slags, drosses, skimmings, spills, and sweepings by the
gravity concentration process, whereby the heavy (more dense) particles
settle faster than the lighter particles in a water medium. The
process steps are: (a) grinding, (b) screening, and (c) gravity
separation in a water medium.
Energy required is that necessary to drive the equipment.
Only minor quantities of atmospheric emissions are expected
from the gravity separation process. These are generated in the crushing
and screening steps. However, large quantities of liquid wastes containing
both suspended and dissolved solids are generated in the gravity
separation step.The liquid wastes are probably treated in settling ponds
and the water recycled or discharged to sewers or streams.
This process does not pose an atmospheric pollution problem;
however, if not controlled, liquid and solid wastes could cause water
pollution problems.
(5) Air Pollution Engineering Manual. Air Pollution Control District,
County of.Los Angeles, Public Health Service Publication
No. 999-AP-40, pp 185-186, 1967.
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C-49
Smelting-Refining Operation
Pretreatment of the scrap removes a portion of the metallic
and nonmetallic impurities found in scrap and physically prepares the
material for further processing by the smelting-refining manufacturing
operation. In this operation, additional metallic and nonmetallic
impurities are removed and the composition of the alloys adjusted to
produce alloy ingots of the desired specifications. The processes
employed to produce the alloy ingots are discussed in the sections below
and shown on the flowsheet by Numbers 10 through 13.
Reverberatory Smelting-Refining Process (10). Brass and
bronze alloys of desired specifications are produced by the reverberatory
smelting-refining process. This is achieved by the removal of metallic
and nonmetallic impurities from pretreated scrap and by the addition of
alloying agents. The process steps are: (a) charging of the rever-
veratory furnace, (b) melting of the charge, (c) fluxing to remove the
impurities, (d) alloying to adjust the composition of the melt, (e) pouring
of thr molten alloy, and (f) casting of the molten alloy into ingots.
This process produces large quantities of atmospheric emissions
and liquid and solid wastes. The atmospheric emissions are composed of
gases and particulate matter. The particulate matter includes such
materials as carbon particles, entrained dust, unburned fuel, and metallic
fumes. The gases in the atmospheric emissions include carbon dioxide and
carbon monoxide from combustion of the fuel, sulfur oxides, halogens,
and nitrogen oxides. Each processing step is a source of atmospheric
emissions.
Charging is a major source of atmospheric emissions from the
reverberatory smelting-refining process. The type and condition of the
scrap are factors that affect the quantity and composition of the emissions.
If the scrap is oily, the emissions will contain, in addition to the
combustion products, unburned hydrocarbons and dust particles. When the
scrap contains large quantities of highly volatile constituents such as
zinc, heavy evolution of fumes will occur.
-------
C-50
Emissions are also dependent upon factors such as location
of the charging doors and method of charging. Overhead charging results
in heavy evolution of emissions containing both gases and particulate
matter. End and side charging results in lower emissions. Batch
charging produces large bursts of emissions that are almost impossible
to control.
Melting of the charge is another major source of atmospheric
emissions from this process. These emissions contain larger proportions
of metallic fumes than those from the charging step.
Emissions data are not available for each individual step.
However, data collected in an earlier survey of industry^ ' revealed
that particulate emission factors for charging-melting ranges from 11.7
to 59.0 Ib/ton of feed charged to the furnace. These particulate
emissions contained, in some cases, 60 to 90 percent zinc, probably as
zinc oxide; in other cases, the particulate emissions contained 33.7 to
73.6 percent nonmetallic materials, 16.7 to 52.8 percent zinc, probably
as zinc oxide, and 0.38 to 4.62 percent copper. No doubt, the particulate
emissions also contained trace quantities of other metallic materials
such as lead and cadmium.
Emission factors are not available for the gaseous emissions.
However, large volumes of gases are evolved from combustion of the
fuel and other sources.
Reported particle size also varied over a wide range, possibly
because the extremely fine particles may have passed through the filter
medium used to collect the samples. In any event, particle sizes were
reported to be less than 20 microns in some cases and in others, less
than 1 micron.
The fluxing process step is a purification or smelting-
refining step, whereby impurities are removed from the melt. These
materials are removed by the addition of gaseous, liquid, or solid fluxes.
Consequently, fluxing can be a major source of atmospheric emissions,
especially in those cases where gaseous fluxes are used. These emissions
may contain a wide variety of metallic constituents such as iron,
(6) Survey conducted by Battelle's Columbus Laboratories.
-------
C-51
manganese, silicon, aluminum, copper, zinc, and lead, along with those
materials from the flux. These emissions may be volatilized from the
melt as fume or carried from the melt by entrainment in the gaseous
emissions. Emission factors for this step are not available.
In the alloying step, virgin metal or specialized scrap is
added to adjust the composition of the melt. Normally, this step is
not a major source of atmospheric emissions, unless high zinc alloys
are being produced. In this case, large quantities of zinc fumes may
be emitted.
Metal oxide fumes are produced as the hot metal is poured
through the air into the molds. Other emissions are also produced,
depending on the type of linings or coverings associated with the mold
as it is filled with hot metal. Thus, the pouring step can be a
significant source of atmospheric emissions and will vary depending on
such factors as composition of the alloy, pouring temperature, pouring
rate, and type of molds. Raw particulate emission factors collected in
an earlier survey were noted to range from 0.4 to 10.9 Ib of dust per ton
of product. These emissions contained a high zinc content; in one case,
60 to 90 percent.
Casting is a minor source of atmospheric emissions.
Thus, the reverberatory smelting-refining process for the
production of brass and bronze ingots is a major source of atmospheric
emissions Raw particulate emissions factors (including both fumes and
dusts) range from 125 to 140 Ib per ton of feed. Composition will vary
but, in general, the emissions will contain both metallic and nonmetallic
constituents. The metallic emissions are composed of, in addition to
a high concentration of zinc, varying concentrations of lead, tin,
copper, silicon, and other metal values. In one case, the dust
collected in a brass and bronze smelter baghouse contained 45.0 to 77.0
percent zinc, 1.0 to 12.0 percent lead, 0.3 to 2.0 percent tin, 0.05 to
1.0 percent copper, 0.5 to 1.5 percent chlorine, and 0.1 to 0.7 percent
sulfur. Gaseous emissions contain, in addition to the combustion
products, volatilized organic materials such as oil and grease, sulfur
oxides, nitrogen oxides, and hydrogen halides such as hydrogen chloride.
The baghouse is the most widely used pollution abatement device.
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C-52
Liquid wastes generated by this process are primarily
cooling wastewater. One source is cooling of the ingots by a water spray.
Significant quantities of solid wastes--slags, flue dusts, and
baghouse dusts--are generated by this process. In one case, 10,000 Ib
of slag and 4,000 Ib of flue dust were generated in the production of
178,000 Ib of brass ingot product. Losses designated as gases, dusts,
and others were estimated at 1,600 Ib.
Thus, the reverberatory smelting-refining process produces
large quantities of potential environmental pollutants. Therefore,
this process has the potential for the production of serious pollution
problems.
Rotary Smelting-Refining Process (11). This process, like
the reverberatory smelting-refining process, produces brass and bronze
ingots from the various types of scrap. Capacity of the rotary furnace
used in this process ranges from several tons to approximately 50 tons
of nonferrous metals. The process steps are: (a) charging of the scrap
through ports on the side of the cylinder, (b) melting of the charge,
(c) fluxing to remove impurities, and (d) alloying to adjust composition
of the melt. Afterwards, the melt is poured and cast into ingots.
Energy required is the fuel used in the various process steps
and electricity to drive the equipment. The rotary furnace is direct-
fired using oil or gas as the fuel.
The process produces significant quantities of atmospheric
emissions, liquid wastes, and solid wastes. The atmospheric emissions
are generated in each of the process steps. Since the rotary smelting-
refining process is similar to the reverberatory smelting-refining
process in that both are direct-fired and the same process steps are
employed, the quantity, composition, and particle morphology of emissions
are comparable. For example, the raw emissions factor for the rotary
smelting-refining process was reported to be 147 Ib of particulate matter
per ton of feed, whereas the factor for the reverberatory smelting-refining
process was reported to be 156.9 Ib of particulate matter per ton of feed.
(7) Spendlove, Max J. , Methods for Producing Secondary Copper, U. S.
Dept. of Interior, Bureau of Mines, Bureau of Mines IC8002 (1961).
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C-53
Liquid wastes generated by this process are the wastewater
from cooling of the ingots during casting. Solid wastes include wastes
such as slag and baghouse dusts.
Thus, the process has a high potential for the production of
serious pollution problems if emissions are not controlled.
Crucible Smelting-Refining (12). The crucible smelting-
refining process is employed for producing brass and bronze alloys from
clean, well segregated scrap and for refining specialized alloys. The
process steps are the same for this process as for the other smelting-
refining processes.
Energy required is the fuel necessary to fire the furnace and
the electricity to drive the equipment. The furnace is indirect fired
using gas or oil as the source of fuel; thus, the charge never comes in
contact with the flame.
The process produces a modest quantity of potential environ-
mental pollutants. Atmospheric emissions are generated in each
processing step but at a rate significantly less than for the rever-
beratory smelting-refining process. For example, furnace emissions
factor for crucible-smelting-refining was reported to range from 6.5
to 12.3* Ib of fume per ton of feed^ , whereas furnace emissions factor
for reverberatory smelting-refining was reported to range from 125 to
(Q\
140 Ib of dust per ton of feedv . Using baghouses with collection
efficiencies of 93.7 percent and 96.2 percent, respectively, the
atmospheric emissions were lowered to 0.24 Ib per ton of feed for the
low zinc alloy and 0.80 Ib per ton of feed for the high zinc alloy.
Liquid wastes are generated in the casting of the ingots. Solid
wastes generated by this process include slags and baghouse dusts.
Composition and particle morphology of atmospheric emissions and
(8) Air Pollution Engineering Manual, Air Pollution Control District,
County of Los Angeles, Public Health Service Publication
No. 999-AP-40-, p 274, 1967.
(9) Industry survey.
* Higher emissions factor resulted from high zinc content in the melt
(24.8 percent vs. 3.8 percent).
-------
C-54
composition of the Liquid and solid wastes should be comparable to those
from the other smelting-refining processes.
Although this process produces significantly less potential
environmental pollutants than the above smelting-refining processes,
improper disposal of the pollutants and/or emitting them to the
environment can result in atmospheric and water pollution problems.
Electric Crucible Smelting-Refining Process (13). This
process is used to produce special high-grade brass and bronze alloys
from treated scrap. The process involves the same process steps as
employed in the other smelting-refining processes.
Energy required is the electricity to drive the equipment and
process the alloy.
Electric crucible smelting-refining produces significant
quantities of atmospheric emissions, solid wastes, and liquid wastes.
These emissions and wastes are generated in the same processing steps
as in the other processes. Also, the composition will be similar.
The primary difference is the atmospheric emissions do not contain
combustion products since the source of heat for the electric smelting-
refining process is electricity rather than fossil fuels. Thus, the
quantity of atmospheric emissions, including both gases and particulate
matter, are significantly reduced. Data are not available for the
gaseous emissions. However, furnace particulate emission factor was
reported to be approximately 2.6 Ib per ton of feed.^ ' The baghouse
removed 96.0 percent of the particulates.* Other wastes generated by
the electric crucible smelting-refining process include liquid wastes
from cooling of the ingots during casting and solid wastes such as
slags and baghouse dusts.
Although this process emits significantly less particulate
matter than other smelting-refining processes, there is the potential
for pollution of air and water if atmospheric emissions and liquid
and solid wastes are not disposed of properly.
* Alloy contained 3.5 percent zinc which accounts in part for the
low furnace emissions factor.
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C-55
Population of Secondary Brass and Bronze Processors
(1) Earth Smelting Corporation
99-129 Chapel Street
Newark, New Jersey
Telephone: (201) MA2-4908
(2) Bridgeport Brass Company
Division of National Distillers
and Chemicals Corporation
30 Grand Street
Bridgeport, Connecticut 06602
(3) Bristol Brass Corporation
999 Broad Street
Bristol, Connecticut
Telephone: 582-3161
(4) W. J. Bullock, Inc.
Post Office Box 539
Fairfield, Alabama
(5) The Bunting Brass and Bronze Co.
715 Spencer Street
Toledo, Ohio 43601
Telephone: (419) EV2-3451
(6) Cerro Corporate Brass Company
Division of Cerro Corporation
16600 St. Clair Avenue
Cleveland, Ohio 44110
Telephone: (216) 481-3000
(7) Colonial Metals Company
Columbia, Pennsylvania
Telephone: (717) 684-2311
(8) Federated Metals
Division of American Smelting
and Refining Company
12 Pine Street
New York, New York
(9) Franklin Smelting and Refining
Company
Castor Avenue
East of Richmond
Philadelphia, Pennsylvania 19140
Telephone: (215) NE4-2231
(10) Freedman Metal Company
310 McGinnis Boulevard
Brooklyn, New York 11222
Telephone: EV9-4131
(11) General Copper and Brass
Company
Post Office Box 5353-D
Philadelphia, Pennsylvania
Telephone: SA6-7111 (215)
(12) Benjamin Harris & Company
Eleventh and State Streets
Chicago Heights, Illinois
(13) Henning Brothers & Smith,
Inc.
91-115 Scott Avenue
Brooklyn, New York
(14) K. Hettleman & Sons
Division of Minerals &
Chemicals
Phillip Corporation
Ninth Street and Patapsco Ave.
Baltimore, Maryland 21225
Telephone: (301) 355-0770
(15) Holtzman Metal Company
5223 McKissock Avenue
St. Louis, Missouri 63147
Telephone: (314) CH1-3820
(16) H. Kramer & Company
1339-15 West 21st Street
Chicago, Illinois 60608
Telephone: CA6-6600
(17) Lewistown Smelting and
Refining Inc.
Post Office Box 708
Lewistown, Pennsylvania
Telephone: (713) 543-5631
(18) Magnolia Metal Company, Inc.
Magnolia Park
Auburn, Nebraska
Telephone: (412) 274-3152
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C-56
(19) Metal Bank of America, Inc. (29) U. S. Metal Products
6801 State Road Company
Philadelphia, Pennsylvania 19135 Post Office Box 1067
Telephone: (215) 332-6600 Erie, Pennsylvania 16512
Telephone: (814) 838-2051
(20) North American Smelting Company
Post Office Box 1952
Wilmington, Delaware
Telephone: OL4-9901
(21) Northwestern Metal Company
North 27th Street
Lincoln, Nebraska
Telephone: 434-6341
(22) Phelps Dodge Refining Corporation
300 Park Avenue
New York, New York
Telephone: 751-3200
(23) Riverside Alloy Metal Division
H. J. Porter Company, Inc.
309 Porter Building
Pittsburgh, Pennsylvania 15219
Telephone: (412) 391-1800
(24) Rochester Smelting and Refining
Company, Inc.
Post Office Box 547
Rochester, New York
(25) Roessing Bronze Company
320 Barbour
Pittsburgh, Pennsylvania
(26) The George Sail Metals Company,
Inc.
2255 E. Butler Street
Philadelphia, Pennsylvania 19137
Telephone: (215) PI3-3900
(27) SIPI Metals Corporation
1722 N. Elston Avenue
Chicago, Illinois
(28) Solken-Galamba Corporation
Second and Riverview Streets
Kansas City, Kansas 66118
Telephone: (913) MA1-4100
-------
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C-58
PROCESSING DESCRIPTION OF THE CADMIUM SEGMENT
OF THE SECONDARY NONFERROUS METALS INDUSTRY
Cadmium Is a byproduct of the primary zinc system. During 1971,
total U.S. cadmium production was 7.9 million pounds of which the,secondary
cadmium segment production was 400,000 pounds or about 5 percent of the total.*
Cadmium is a poisonous metal. Ingestion as fumes or in other
forms is known to cause the painful "itai-itai" disease. Hence, it is
generally considered both necessary and safe to use a replacement metal
that provides all the excellent properties of cadmium without its
toxicity. Zinc is a possible replacement metal.
Raw Materials
Raw material is available both as old and new scrap. Examples
of old scrap are: cadmium plated parts from junked automobiles, nickel-
cadmium batteries, cadmium coated electrical contact points, and used
cadmium alloys. New scrap, which constitutes only a small percentage of
the total, consists of factory rejects from manufacturing of bearings
etc., Ni-Cd battery rejects, and scrap from plating (electrodeposition)
cells, and scrap solder used to solder aluminum.
In the United States, cadmium is not recovered from junked
automobile parts because of economics. Also, used nuclear reactor
control rods (containing 80 percent cadmium and 20 percent silver and
indium) are not processed by the secondary cadmium industry. Instead
these rods are sent to fuel processors (e.g., Mallinckrodt Chemical Works,
St. Louis, Missouri).
Products
Products of the cadmium segment are as follows:
(1) Recast cadmium metal (sticks and balls)
(2) Recast cadmium alloys.
* U. S. Bureau of Mines
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C-59
Process Description
The three manufacturing operations employed in scrap processing
are scrap pretreatment, smelting/refining, and casting—as described below
and as shown on the flowsheet of this segment. Of these, the major
operation—smelting/refining—involves pyrometallurgy.
Scrap Pretreatment Operation
The only process in this operation is the vapor degreasing of alloy
scrap as noted by Process 1.
Vapor Degreasing Process (1). This process removes oil and
grease .adhering to the scrap alloys.
The process steps are: (1) heating solvent to generate vapors
(perchloroethylene), (2) circulating solvent vapors through the scrap in a
pot, and (3) condensing solvent for reuse.
Heat energy is the main requirement of this process.
The major waste generated is the liquid waste—grease/oil residue
from the solvent regeneration pot. The quantities of this waste are very
small and are usually either incinerated at the municipal incinerator or
dumped into sewer lines. Other waste generated is atmospheric emission
composed of organic vapors.
The potential for pollution from this process is not significant,
and is regulated in many states.
Smelting/Refining Operation
Two processes—melting or retorting—are used to recover cadmium
from scrap.
Alloy Smelting/Refining Process (2). This process purifies the
pretreated alloy scrap.
The process steps involved are: (1) heating the alloy scrap,
(2) adding the flux, (3) skimming the slag, and (4) pouring the molten
-------
060
metal Into molds for casting.
Heat energy Is utilized in the process.
Wastes generated are atmospheric emissions containing metal fumes
and solid wastes consisting of slag. The fumes are not significant to
cause any pollution. The slag is recycled and ultimately disposed of in
a landfill. Thus, the process has a low pollution potential.
Retort Smelting/Refining Process (3). This process recovers pure
cadmium by distilling cadmium alloys.
The process steps are: (1) charging the retort, (2) melting the
charge, (3) vaporizing the cadmium, (4) condensing the cadmium, (5) pouring
the molten metal, (6) casting the ingots, and (7) discharging retort
residue for shipping to residue processors.
Heat energy is utilized in the process. The potential pollutant
generated by this process is atmospheric emissions containing cadmium fumes.
If properly controlled, this process has little potential for
producing serious pollution problems.
Melting Process (4). This process purifies the scrap cadmium
metal collected from electrodeposition cells as sticks and rods. These
rods and sticks are usually contaminated with acid salts or mixed with
zinc occasionally.
The process steps are: (1) charging scrap to pot, (2) melting
the charge, (3) adding the flux, (4) chlorinating when required for zinc
removal, (5) skimming the slag, (6) pouring into molds, and (7) casting
the ingots.
The process utilizes heat energy.
Wastes generated in the process are: (1) atmospheric emissions
containing cadmium fume, zinc chloride dust when dezincing operation is
done, (2) solid waste consisting of slag, and (3) liquid waste composed
of cooling water which may be recycled. The zinc chloride dust is
collected with a baghouse. Slag generated is about 2000 pounds per year
in a plant producing 200,000 pounds of cadmium per year. The slag which
contains some cadmium is disposed of in a landfill.
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C-61
Thus, this process has the potential for the production of
pollution problems.
Casting Operation
This is a simple operation and consists of one process step.
Casting Process (5). The molten alloy and the molten metal
from the retorting and melting processes are cast into required shapes
by this process. The processing steps consist of pouring the molten
material into molds and casting with water cooling.
Electrical energy is used to circulate cooling water and
auxiliary equipment.
No wastes are generated in the process. The process has no
pollution potential.
Population of Secondary Cadmium Processors
(1) Belmont Smelting & Refining Works
320 Belmont Avenue
Brooklyn, New York
(2) Joseph Behr & Sons, Inc.
1100 Seminary Street
Rockford, Illinois
(3) United Refining and Smelting Company
3700-20 N. Runge Avenue
Franklin Park, Illinois 60131
(4) Wolverine Metal Company
6500 E. Robinwood Street
Detroit, Michigan
-------
8-7 6 5 4 3
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-------
C-63
PROCESS DESCRIPTION OF THE COBALT SEGMENT OF
THE SECONDARY NONFERROUS METALS INDUSTRY
The volume of scrap available to the cobalt segment of the
secondary nonferrous metals industry is estimated at two million pounds
annually. The majority of this is recovered as cobalt-base or nickel-
base alloy in the United States. Some of the refined high grade cobalt
scrap is exported to Japan for recovery of pure metal. Approximately
5 to 10 percent of the scrap cobalt is used in the production of chemicals.
Emissions from the cobalt segment include (1) water wastes from
vapor degreasing, pickling and vacuum melting, and (2) minor quantities of
wastes to the ambient air and land from other process steps. Generally,
these wastes are effectively controlled and therefore their potential
for pollution is minimized. However, if the control methods are rendered
ineffective, a moderate potential for pollution of mainly the waterways
exists.
Raw Materials
Raw materials consist of cobalt bearing superalloy grindings
and turnings and scrap superalloys (stellite, etc.) from jet engine
components. The total scrap available can be classified into cobalt-
base supe -Hoy scrap containing 50 to 60 percent cobalt and nickel-
base scrap consisting of 10 to 20 percent cobalt. A quantitative breakdown
of the scrap into these categories is not available because of the lack
of information, published or otherwise.
Products
Products from the secondary cobalt industry are as follows:
(1) Pig alloys (stellites, etc.)
(2) Refinery grade cobalt scrap.
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C-64
Process Description
Processing of scrap cobalt alloys involves three major operations-
scrap pretreatment, smelting, and casting/refining. These operations are
shown in the attached flowsheet for this segment.
Scrap Pretreatment Operation
A complex series of processes are involved in this operation.
Some companies specialize in these processes and produce a clean scrap as
their product for sale to smelting facilities.
The four processes (Process 1 through Process 4) employed under
this operation are described below.
Hand Sorting Process (1). This process identifies the scrap
components and separates them into cobalt-base, nickel-base and nonpro-
cessable components. The hand sorting operation is also aided by
identifying the source of scrap and storing them in different lots to
avoid mixing.
The processing steps are: (1) spreading the dirty scrap on
the floor, and (2) visually identifying and segregating the scrap.
Human labor is the only requirement of this process.
Waste produced is a minor amount of dust which is collected as
sweepings and disposed of in trash cans and ultimately in a landfill.
The process has no potential for pollution. The cobalt free
scrap collected in the process is sent to other processing facilities.
Vapor Degreasing Process (2). This process removes the oil and
grease from the scrap by using hot vapors of perchloroethylene.
The processing steps are: (1) charging dirty scrap to degreasing
unit, (2) heating to generate and circulate hot solvent vapor, and (3)
discharging the degreased scrap to the blasting box.
Heat energy is the main energy requirement of the process.
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C-65
Waste emissions include minor amounts of solvent vapor to the
atmosphere and grease and oil wastes to be incinerated or disposed of in
severs.
Since the process is a closed loop operation, the only signifi-
cant waste with a potential for pollution is the grease and oil from the
solvent recovery unit.
Blasting Process (3). This process cleans the surface of the
scrap material of all extraneous dirt, oxides, and rust.
The process steps are: (1) blast the scrap either batchwise or
continuously with grit, and (2) discharge the clean scrap.
The process requires electrical energy to obtain compressed
air used in the blasting equipment.
Since the process is a closed loop operation, no significant
wastes are generated. Hence the process has no potential for pollution.
Pickling and Chemical Treatment Process (4). Because the alloy
produced as the final product of this segment has to be free of all
impurities, the pickling process is utilized to clean the scrap of
all residual oxide coatings. The chemical treatment operation is a trade
secret and is known to remove lead from the scrap.
The process steps are: (1) treating the scrap with a mixture
of acids to remove rust and oxides, (2) treating with a chemical to
remove lead, and (3) washing the scrap with water.
The process requires electrical energy to drive pumps and
other auxiliary equipment.
Waste discharges include (1) small amount of acid fumes and
(2) acidic wastewater containing metallic Impurities.
The acidic wastewater is neutralized before discharge to the
waterways or sewer and hence has a reduced pollution potential. The
acid fumes are usually not substantial to create serious ambient air
pollution problems.
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C-66
SmeIting/Refining Operation
The treated scrap Is virtually free of all impurities except for
some dissolved gases which are removed by smelting/refining. Usually this
operation is carried out in an electric arc vacuum furnace or a vacuum
induction furnace.
Vacuum Melting Process (5). This process refines the scrap by
removing volatile impurities under the influence of both heat and vacuum.
The process steps include: (1) charge scrap to the vacuum
furnace, (2) evacuate the system, (3) melt the scrap by electric arc or
induction, and (4) discharge the molten alloy into molds.
Large amounts of electrical energy are used both to create
vacuum and heat the charge.
No significant wastes are produced. The vacuum pump discharge
is contaminated with traces of gaseous wastes too insignificant to
constitute any pollution. Vaporized heavy metals and other potential
pollutants are trapped by the vacuum pump.
Casting Operation
This is the final operation of the secondary cobalt industry.
The castings produced by this operation are used as pig alloys or if the
quality of the alloys produced is refinery grade cobalt alloy, it may
be shipped to a cobalt metal recovery facility.
Casting Process C6J. This process produces castings of pig
alloy from the molten charge obtained in vacuum melting.
The process steps are: (1) pouring the molten metal into molds
and (2) casting the ingots.
Energy requirements of this process are not significant.
No wastes are produced in the process.
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C-67
Population of Secondary Cobalt Processors
Alloy Metal Products, Inc.
626 Schmidt Road
Davenport, Iowa 52808
Telephone: (319) 324-3511
Max Zuckerman and Sons
Music Fair Road
Owings Mills, Maryland 21117
Telephone: (301) 484-0400
Pfizer Metals and Composite Products
235 E. 42nd Street
New York, New York 10017
(Processing only inhouse scrap)
Union Carbide Stellite Division
Kokomo, Indiana
Telephone: (317) 457-8411
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8 .
SCRAP PRETREATMENT
D
C:
SMELTING/REFINING
CASTING
8
LEGEND
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C-69
PROCESS DESCRIPTION OF THE COPPER SEGMENT
OF SECONDARY NONFERROUS METALS INDUSTRY
Tonnage-wise, the copper segment (which produces refined
copper) constitutes one of the major segments of the secondary
nonferrous metals industry. Based on 1972 data , 1,210,070 tons of
copper were recovered from scrap. Of this production, 280,730 tons were
recovered by this segment and 571,095 tons were recovered by the brass
and bronze segment. An additional 381,790 tons were recovered by the
primary nonferrous metals industry. Emissions from the copper segment
of the secondary industry include: gases and particulate materials
which are emitted to the atmosphere, liquid wastes emitted to the water
system, and solid wastes emitted to the land.
Raw Materials
Sources of raw materials to this industry include both new
and old scrap. New scrap, which accounted for approximately 21 percent
of the copper recovered from the scrap in 1972, refers to scrap produced
in the manufacturing process by a fabricator of a finished product.
Old scrap, comprising obsolete, worn out, or damaged articles, accounts
for approximately 69 percent of the copper recovered by the copper
segment in the U. S.
Segregating scrap according to classification standards is
one of the most important steps in the recovery of secondary metals.
(2)
Currently, copper-bearing scrap is classified into 54 types as shown
in Table III.
Copper scrap as received generally contains metallic and
nonmetallic impurities. Included among these are: lead, zinc, tin,
antimony, iron, manganese, nickel, chromium, precious metals, and
organic compounds such as plastics, oils, and greases. These impurities,
which are removed during the recovery of copper, constitute major sources
(1) "Copper industry in January 1973", Mineral Industry Surveys, U. S.
Dept. of the Interior, Bureau of Mines, Washington, D. C.
(2) Circular NF-58, National Association of Waste Materials Dealers, Inc,
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C-70
of emissions to the environment, if not collected and disposed of by
an acceptable method or recovered as by-products.
Products
Products from the copper segment of the secondary nonferrous
metals industry include:
(1) Babbit, lead, and solder recovered from the
sweating process. This mixture of materials may
be made into white-metal alloys, used for lead
and tin additions to copper base alloys, or sold
as produced to a refiner.
(2) Copper powder
(3) Copper shot
(4) Fire-refined copper
(5) Electrolytic-refined copper
(6) Oxygen-free high conductivity copper (O.F.H.C.)*
Process Description
The recovery of copper from scrap involves three manufacturing
operations: scrap pretreatment, smelting, and refining/casting. These
operations and the individual processes under each operation are shown
on the flowsheet entitled "Copper Segment of the Secondary Nonferrous
Metals Industry".
Scrap Pretreatment Operation
Copper scrap is pretreated prior to smelting to remove some
of the metallic and nonmetallic impurities or contaminants and to
physically prepare the material for further processing. Three types of
processing--mechanical, pyrometallurgical, and hydrometallurgical--are
used. The pretreatment process varies according to the type of scrap.
The individual pretreatment processes are numbers 1 through 14 on the
segment flowsheet.
* O.F.H.C. is a trade name of the U. S. Metals Refining Company.
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071
Stripping Process (1). Insulation and lead sheathing are
removed from electrical conductors by special stripping machines or
by hand.
Energy demand is that needed to drive the equipment.
The process produces quantities of solid wastes. These
wastes include lead and insulation. The lead is probably sold to a
secondary lead smelter, whereas the insulation may be sent to a landfill
or incinerator.
The process has little potential for production of serious
pollution.
Briquetting Process (2). Wire, thin plate, wire screen, and
other bulky scrap are pressed into briquettes, bales, or bundles by
hydraulic presses. In this form, the scrap is easier to handle, store,
and load into the furnace.
Energy required is that necessary to drive the presses.
The process produces essentially no wastes or emissions.
The process has no potential for production of pollution
problems.
Shredding Process (3). Large items are reduced in size by
pneumatic cutters, electric shearing machines, or manual sledging.
The smaller pieces are easier to handle.
Energy demand is limited to that needed to drive the equipment,
The process may produce a small quantity of atmospheric
emissions consisting of dusts with an approximate composition of the
scrap. Collection of these dusts may be via a baghouse. Most likely,
the emissions are not controlled.
The process has essentially no potential for production of
pollution problems.
Crushing Process (4). Brittle spongy turnings, borings, and
long chips are densified by the crushing process. The process steps
are: (a) crushing in hammer-mills or ballmills to reduce bulk, and
(b) running over a magnetic separator to remove tramp iron.
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C-72
Energy demand is that required to drive the equipment.
The process produces small quantities of atmospheric emissions
consisting of dust particles composed of dirt, organic compounds from
the scrap, heavy metals, and solid wastes. Most likely, the area may be
hooded to carry the dust away from the vicinity of the crushing.
The process has little or no potential for causing serious
pollution problems.
Grinding Process (5). Prills or metallics are seperated from
the gangue in slags, drosses, skimmings, foundry ashes, spills, and
sweepings by the grinding process. The process steps are: (a) grinding,
(b) screening, and (c) gravity separation.
Energy required is that to drive the equipment.
The process produces atmospheric emissions, liquid wastes, and
solid wastes. The atmospheric emissions are dusts from the grinding
and screening steps. These dusts may contain, in addition to fluxing
materials and dirt, small quantities of heavy metals.
The liquid wastes containing both dissolved and suspended solids
are generated in the gravity separation step. The solid wastes are
generated during the screening step.
As significant quantities of atmospheric emissions, liquid wastes,
and solid wastes are generated by the grinding process, the process has
a potential for the production of pollution problems.
Muffle/Kiln Burning/Drying Process (6). Much of the scrap contains
oil, grease, cutting fluids, insulation, and moisture. These components
may be removed prior to smelting by the muffle/kiln/burning/drying
process. The process steps are: (a) charging of the scrap to the
muffle or kiln, and (b) heating to remove the organic contaminants and
moisture, afterwhich the treated scrap is removed for further processing.
Energy required for this process is from gas or fuel oil to heat
the furnace and electricity to drive the equipment.
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C-73
The process produces significant quantities of atmospheric
emissions. These emissions consist of both gases and particulate
matter. The gaseous emissions are composed of the gases from combustion
of the fuel and the organic contaminants. Depending on the organic
contaminants, the gases may contain such materials as the chlorides,
sulfur oxides, fluorides, and hydrocarbons. The particulate matter
(fume and dust) is composed of a variety of'heavy metals depending on
the composition of scrap. Examples of heavy metals which may be found
in the particulate matter are copper, zinc, tin, and lead.
Emissions data are not available for the burning/drying of
all types of scrap. However, from burning of insulated wire,
particulate emissions are estimated at 275 Ib per ton of wire processed
or an annual emissions total of 41,000 tons based on treating 300,000
tons of insulated wire.
A variety of methods may be employed to control the atmospheric
emissions. Included in the list are afterburners to destroy the
hydrocarbons and other organic materials, wet scrubbers to remove the
particulate matter and toxic gases, and baghouses to remove the
particulates.
In view of the toxic and hazardous nature o'f the atmospheric
emissions, this process could be a source of serious pollution problems
if the emissions are not controlled.
Sloping Hearth Sweating Process (7). Scrap such as journal
bearings, radiators, and lead-sheathed cable contains lead, solder, or
babbitt which would contaminate the melt. These contaminants are removed
by the sloping hearth sweating process. The process steps are:
(a) charging the preheated furnace with scrap, (b) melting the low-
melting constituents, (c) raking the sweated scrap over the hearth to
remove all of the low-melting alloys, (d) collecting the solder, lead,
or babbitt in a collecting pit, and (e) removing the sweated scrap for
further processing.
Energy for this process is from gas to fire the furnace.
(3) Vandegrift, A. E., et al., Particulate Pollutant System Study,
Handbook of Emissions Properties, Midwest Research Institute,
Kansas City, Missouri, Volume III, p 406 (May 1, 1971).
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C-74
In addition to the lead, solder, or babbitt which are
recovered for subsequent use or sale, the process produces atmospheric
emissions. These emissions are composed of gases and fumes. The gases
contain the products from combustion of the fuel and any organic matter
present in the scrap. Particulate matter is composed of such heavy
metals as lead, tin, antimony, and copper, and organic materials such
as soot.
Emissions data are not available for the sweating of the
various types of scrap. However, the sweating of radiators results
in the evolution of 15 Ib of particulate matter per ton of scrap.
Emissions may be controlled by baghouses, wet scrubbers,
and electrostatic precipitators.
Due to the hazardous nature of some of the pollutants and
the quantity emitted, this process has a potential for the production
of serious pollution problems.
Reverberatory Sweating Process (8). For removal of solder
from scrap which is difficult to sweat, i.e., the solder remains in
seams and folds when melted, the reverberatory sweating process may be
employed. For this process a reverberatory furnace with a shaking
grate is used. The molten solder removed from the items by a shaking
motion falls to the floor and flows to the collecting sump. The
process steps are: (a) charging the furnace, (b) heating the scrap
to melt the low-melting components, (c) shaking to remove the low-melting
components, and (d) collecting the low-melting material. The sweated
scrap is subsequently removed for further processing.
Energy demand is from the fuel oil or gas to heat the direct-fired
reverberatory and electricity to drive the equipment.
Waste materials produced by this process are atmospheric
emissions consisting of gases and particulate matter. Composition of
these emissions is similar to those from the sloping hearth smelting
process. In fact, if the same type of scrap were sweated by both
processes, the emission would be essentially identical with the possible
exception that the emissions from the reverberatory sweating process may
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C-75
contain some dust resulting from shaking action. This dust is carried
from the furnace by entrainment in the combustion gases.
Particulate emission factor for reverberatory sweating
process is estimated at 15 Ib/ton of radiators. The factor may be
lower or higher for other types of scrap.
Emissions are controlled with the same equipment as is used
for other sweating processes.
Atmospheric emissions produced by this process could cause
pollution problems.
Pot Sweating Process (9). Removal of low-melting constituents
from copper scrap is achieved by the pot sweating process. The process
steps are: (a) dipping the scrap into a pot of molten alloy,
(b) melting the low-melting constituents, and (c) removing the sweated
scrap from the pot.
Energy required is fuel--gas or oil--necessary to keep the
pot of alloy molten.
Potential pollutants generated by this process are atmospheric
emissions containing fumes and possibly some gases if the scrap to be
sweated contains any organic matter. Composition of emissions and
emission factors should be comparable to those from other sweating
processes.
The process has the potential for producing pollution problems,
as well as hazards to the operators of the equipment.
Tunnel Sweating Process (10). This process is used by some
smelters to sweat copper scrap. The process steps are: (a) load
scrap placed in trays or on racks onto a continuous conveyor passing
through the tunnel furnace, (b) remove the major portion of the low-
melting constituents by passing the scrap through a heated tunnel furnace,
and (c) dump hot partially sweated scrap onto tilted screen to remove
remaining low-melting constituents. The molten low-melting constituents
are collected in a floor sump.
Energy required is from oil or gas to heat the scrap and
electricity to drive the equipment.
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C-76
This process produces atmospheric emissions composed of
gases (combustion gases from the fuel and gases from burning or
volatilization of organic contaminants in the scrap), and particulate
matter (fumes and possibly some dust from dropping of the partially
sweated scrap onto the screen). The individual components in the
emissions will be the same as those in emissions from other similar
processes.
Particulate emission factor may be somewhat higher for this
process (>15 Ib/ton of scrap sweated) as the partially sweated scrap is
exposed to the atmosphere while hot. This results in rapid oxidation
of molten metal and subsequent volatilization of the oxides as fumes.
The process produces atmospheric emissions which can cause
pollution problems.
Ammonium Carbonate Leaching Process (11). The copper values are
(45)
leached from copper scrap by the ammonium carbonate leaching process. *
The process steps are: (a) heating copper scrap in an ammonium carbonate
solution while sparging the solution with air, (b) separating the crude
copper ammonium carbonate solution from the leach residue, and (c) puri-
fying the clarified copper solution. Copper values are then recovered
from this intermediate product by the steam distillation process (12)
or by the hydrothermal hydrogen reduction process (13).
The energy required for this process is that necessary to
heat the solution and to drive the equipment.
The potential environmental pollutants generated by this
process are atmospheric emissions, liquid wastes, and solid wastes.
The atmospheric emissions are gases emitted from the leaching of the
copper scrap with ammonium carbonate in the preparation of the crude
copper ammonium carbonate solution. These emissions contain ammonia,
(4) Kunda, W., et al., "Production of Copper from the Amine System",
presented at Extractive Metallurgy Division Symposium on Copper
Metallurgy, Denver, Colorado, February 15-19 (1970).
(5) Ryan, V. H., et al., Production of Copper Powder: AICE,
National Meetings, Washington, D. C., March 9, 1954.
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C-77
water vapor, carbon dioxide, nitrogen, and excess air. Before being
emitted to the atmosphere, the gases are cleaned via a wet scrubber
which removes the ammonia and carbon dioxide.
Solid wastes generated by the process are the leach residues
and residues from the various stages of solution purification.
Essentially the only liquid wastes generated are those
adsorbed on the surface of the discarded residues. Other liquid
effluents generated are recycled to the process.
Thus, this process has essentially no potential for the
production of atmospheric pollution problems. The only atmospheric
emission generated is nitrogen enriched air from the leaching operation.
However, there is a potential for water pollution resulting from disposal
of the leach residues from the ammonium carbonate leaching of the copper
scrap and the disposal of purification residues. Pollution problems
resulting from disposal of liquid wastes are negligible as essentially
all of the liquid effluents are recycled.
Steam Distillation Process (12). Copper oxide is precipitated
from the copper solution prepared from the ammonium carbonate leaching
process by the steam distillation process. The process steps are:
(a) heating the copper solution to precipitate the copper, (b) separating
copper values from slurry, (c) drying the precipitated copper oxide,
and (d) recycling the aqueous effluent to the ammonium carbonate
leaching process to prepare fresh copper. The copper oxide is an
intermediate product for the production of copper by such processes
as (15) and (24). Step (a) is conducted at atmospheric pressure (boiling)
or under pressure.
The energy requirement is that to produce the steam to heat
the calciner.
The process produces some atmospheric emissions from the copper
ammonium carbonate decomposition step (Step a), and during drying of the
copper oxide, and possibly some liquid wastes. The gaseous emissions
from Step (a) are composed of essentially water vapor, ammonia, and
carbon dioxide. These gases may contain a trace of copper carried
from the system by entrainment in the gaseous emissions. Those emissions
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C-78
from drying of the copper oxide contain gaseous emissions composed of
water vapor, carbon dioxide, and possibly some ammonia, and particulate
emissions consisting of essentially copper along with trace quantities
of other metals found in the copper oxide as impurities.
Control of the atmospheric emissions should be possible by
using a wet scrubber for controlling those from Step (a), and by using
a wet scrubber or baghouse to control those from the calciner.
The liquid wastes are dilute ammonium carbonate solutions from
washing the precipitated copper oxide. These contain, in addition to
ammonium carbonate, copper compounds along with trace quantities of
impurities associated with the copper. In most cases, these wastes
can be recycled.
Because of the small amount of wastes produced by this process,
it is expected that pollution problems associated with the wastes are minor.
Hydrothermal Hydrogen Reduction Process (13). The copper value
is precipitated as metallic copper from the ammonium carbonate leaching
process by the hydrothermal hydrogen reduction process. The process
includes fhe following process steps: (a) heating the copper solution
in an autoclave v.'ith hydrogen at an elevated temperature and pressure to
precipitate the copper, (b) removing the stripped liquor from the
metallic copper, (c) washing the copper free of adsorbed liquor, (d) drying
and sintering the copper powder under a hydrogen atmosphere, (e) pulver-
izing the sinter, and (f) screening the powder.^ ' The reduction of
the copper solution is conducted at approximately 325 F and 500 psig of
hydrogen. The stripped liquor is recycled to produce more copper
solution by the ammonium carbonate leaching process.
The energy requirement is that needed to heat the copper
solution in the reduction step, to dry and sinter the copper product,
and to drive the pulverizing and screening equipment.
Atmospheric emissions and possibly liquid emissions are
generated by this process. Sources of atmospheric emissions are
(1) drying and sintering of the copper powder, (2) pulverizing and
(6) Kunda, W., et al., "Production of Copper From Amine Carbonate
System", 1970 Extractive Metallurgy Division Symposium on Copper
Metallurgy, Denver, Colorado, pp 40-43 (1970).
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C-79
screening of the copper sinter, and (3) reduction of the copper solution.
The emissions from drying and sintering of copper powder contain water
vapor, hydrogen, ammonia, and carbon dioxide as gases, and possibly
particulates of copper powder or copper oxide. Those from the
pulverizing and screening of the copper sinter contain particulates
of copper. The gas in these emissions is entrained air. Hydrogen and
water vapor are emitted from reduction of the copper solution.
Liquid wastes are ammonium carbonate solutions containing such
metal value as copper, nickel, lead, and zinc. Normally, these are
regenerated and recycled. If the ammonia and ammonium carbonate contents
are low, the solutions may be discarded. No solid wastes are produced
by this process.
Thus, the process produces emissions and wastes which could
cause pollution problems. However, the quantity of emissions is expected
to be low; therefore, pollution problems associated with this process
are expected to be minor.
Sulfuric Acid Leaching Process (14). Copper values are
extracted from scrap copper as copper sulfate by this process. The
process steps are as follows: (a) digesting copper scrap in hot aerated
sulfuric acid solution to convert the copper values to copper sulfate,
(b) separating the soluble copper sulfate from the undissolved portion
of the scrap by filtration, and (c) purification of the copper sulfate
solution. This intermediate product — aqueous copper sulfate solution--
is a source of copper for the electrowinning process.
The energy requirement is that to heat the digester solution
and to operate the auxiliary equipment.
The wastes produced by this process are atmospheric emissions
and solid waste. The source of atmospheric emissions is the digester.
These consist of air containing fine droplets of the pregnant leach
liquor. Most are equipped with demisters to reduce the emissions to
the environment.
The undissolved portion of the scrap and residues formed during
the purification step are the sources of solid wastes. These are, most
likely, disposed of via landfill. However, care must be taken to prevent
contamination of the water by leachate from the landfill. A portion of
the wastes may be reclaimed.
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This process produces essentially no atmospheric emissions
and, thus, does not pose an atmospheric pollution problem. However,
solid wastes disposal may result in a water pollution problem.
Smelting Operation
The scrap pretreatment operation achieves a partial purification
or denslfication of copper-bearing scrap. Further purification is
achieved by the smelting operation as outlined in the segment flowsheet
by Processes 15 through 17. Via this operation, additional metallic
and nonmetallic impurities are removed from the copper scrap to produce
copper intermediate products (black copper and blister copper) containing
(75 to 88) and (90 to 99) percent copper, respectively.
Blast Furnace (Cupola)/Reverberatory Smelting Process (15).
Low-grade scrap (irony copper and brasses, motor armatures, foundry
sweepings, slags, drosses, and skimmings) is treated by the blast furnace
(cupola)/reverberatory smelting process to recover the copper as an
intermediate product—black copper—for further processing. In this
process, two major pieces of equipment are used—the blast furnace and
the reverberatory furnace. The blast furnace is used to purify the scrap,
whereas the reverberatory furnace is used to separate the slag from the
molten metal. The process steps for this process are: (a) charging of
the blast furnace (cupola), (b) melting the charge, (c) mixing of molten
mass, (d) tapping of slag and metal into the reverberatory furnace,
(e) allowing slag and metal to separate into layers, and (f) tapping of
slag and black copper melt. Afterwards, the molten melt of black copper
is either cast into ingots or transferred in the molten state to the
converter for further processing.
Energy required for this process is from coke which serves both as
a reducing agent and a source of fuel.
Potential environmental pollutants produced by this process are
atmospheric emissions, solid wastes, and liquid wastes. The atmospheric
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emissions are composed of gases and particulate matter. The gases are
generated by the combustion of coke and burning of any organic
constituents contained in the charge. Chemical composition will vary
depending on the type of scrap but generally the gases will contain
carbon dioxide, carbon monoxide, nitrogen, sulfur oxides, .and possibly
nitrogen oxides. The gases may also contain halogens and hydrocarbons,
if present in the charge.
The particulate emissions are composed of a mixture of fumes,
metal particles formed by the volatilization and condensation of metal
values, and dusts removed from the furnace by entrainment in the gaseous
emissions. These emissions normally contain such materials as zinc,
lead, tin, copper, antimony, chlorine, and unburned carbon. Zinc is
normally the major component.
Data are limited on the composition of particulate emissions
from the blast furnace. However, baghouse dusts from one installation
had the following composition:
.(7)
At this installation,
Zinc
Lead
Tin
Copper
Antimony
Chlorine
the cupola melt
Copper
Tin
Lead
Antimony
Iron
Zinc
Sulfur
Percent
58-61
2-8
5-15
0.5
0.1
0.1-0.5
contained the following:
Percent
75-88
1.5
1.5
0.1-0.7
0.5-1.5
4-10
0.5-1.25
(7) Spendlove, M. J., Information Circular 8002, U. S. Dept. of
Interior, Bureau of Mines (1961).
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Emission factors vary depending on the composition of the
charge. However, for treating scrap and residues, the emission factor
is estimated at 50 Ib per ton of charge.^
Solid wastes generated are slags and baghouse dusts (discussed
above). Composition of the slag is variable depending on such factors
as type of scrap and fluxing agent. However, the slag will normally
have a composition approximating the following:
Percent
Iron Oxide (FeO) 29
Calcium Oxide 19
Silica 39
Zinc 10
Copper <1.5
Tin 0.7
It will represent approximately 5 percent of the charge.
Liquid wastes are generated as wastewater from cooling the
blast furnace, in casting of the ingots, and quenching of the slag.
Thus, the blast furnace/reverberatory smelting process has
a high potential for the production of serious pollution problems. These
problems could result from pollution of the atmosphere and the water
systems, if the wastes and emissions are not collected and disposed of
in a nonpolluting manner.
Converter Smelting Process (16). Black copper is purified,
i.e., the heavy metals concentration is lowered to produce an inter-
mediate product containing 90 to 99 percent copper, by the converter
smelting proces-s. The process steps are: (a) charging of the converter
with molten black copper, (b) blowing of the molten charge (blow 1),
(c) deslagging, (d) blowing of molten charge (blow 2), and (e) removing
the slag, if any is formed. Afterwards, the copper — blister copper—is
poured and cast into ingots for refining or transferred in the molten
state directly to the refining furnaces. Some produce the copper shot
product by quenching the blister copper to form small pellets.
(8) Vandegrift, A. E., et al., Particulate Pollutant System Study,
Volume 1-Mass Emissions, Midwest Research Institute, Kansas City,
Missouri (May 1, 1971).
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Essentially no energy is required for this process. In fact,
care must be taken to prevent overheating of the converter.
The process produces atmospheric emissions, solid wastes, and
liquid wastes. The atmospheric emissions contain both particulate
matter and gas. The particulate matter is composed of fumes (metal
particles resulting from volatization and condensation of metal values)
and dusts entrained in the gaseous emissions.
The major sources of particulate emissions are the charging-
melting and blowing steps. Emission (furnace) factors for these steps
are estimated at 30 and 39 Ib of particulate matter per ton of charge
processed, respectively. Emission factor for pouring is estimated at
only 0.6 Ib of particulates per ton of charge processed. Emission
factor for casting is comparable to that for the pouring step. The
high emission factors for the charging-melting and blowing steps result
from the heavy evolution of fumes when the charge is loaded into the
furnace and melted down and when the melt is fluxed with a gaseous
fluxing agent (air).
Quantitative analytical data are not available on the com-
position of these emissions. However, qualitatively, the particulate
emissions contain such metal values as tin, lead, antimony, iron, zinc,
sulfur, copper, silicon, and calcium.
These emissions are in the form of dust and fumes. The dust
is carried from the converter by entrainment in the "blowing" air,
whereas the fumes result from volatization and condensation of the
volatile metals. The fumes have a particle size in the sub-micron
range. The dust particles are much larger, probably in the 5 to 20
micron range or larger. The particles have no definite shape, i.e.,
an irregular shape.
The atmospheric emissions can be controlled with baghouses,
electrostatic precipitators, and scrubbers. Probably the most widely
used device is the baghouse with control efficiency of approximately
95 percent.
Other wastes include solid waste and liquid wastes. The solid
wastes generated are baghouse dusts and converter slags. Much of the
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C-84
solid wastes are recycled or treated for recovery of metal values. For
example, the converter slags may be returned to reverberatory smelting
(Process 15) for copper recovery. Liquid wastes are generated as
wastewater from casting of the ingots, from wet scrubbers, if used, and
from quenching of the slags.
Thus, this process can be a source of serious pollution
problems, if the pollutants are not collected and disposed of in a
nonpolluting manner.
Electric Smelting Process (17). This process is very similar
to Processes 15 and 16 in that blister copper and black copper, inter-
mediate products for refining by the electric smelting process operation,
can be produced by both processes. The advantage of Process 17 over the
combination of Processes 15 and 16 is that the quantity of atmospheric
emissions, both gases and particulates, is significantly reduced. Using
electricity in place of coke as the fuel and pure oxygen in place of air
to oxidize the melt result in lower atmospheric emissions. Consequently,
since much of the particulate emissions is carried from the smelting
furnaces by entrainment in the gases, the reduced volume of gases
results in a reduced amount of particulate matter. Thus, with the
strong emphasis being placed on pollution abatement, this process is
being viewed strongly as the preferred process for smelting of copper scrap.
The process steps for the electric smelting process, which
are essentially the same as those for Processes 15 and 16, are:
(a) charging of the electric furnace, (b) melting of the charge,
(c) removing the slag, (d) adding high iron scrap and virgin copper,
(e) blowing the melt (blow 1), (f) skimming to remove the slag formed
by blow 1, (g) adding more flux, (h) blowing the melt (blow 2), (i) skim-
ming to remove the slag formed by blow 2, and (j) transferring the melt
to the holding furnace for fire-refining or casting as blister copper.
In some cases, the copper is given a third blow termed the "finish blow".
The energy required for this process is the electricity
necessary to melt the charge and drive the equipment. The heat evolved
during the blowing is sufficient to keep the melt molten. In fact, in
many cases, care must be taken to prevent overheating of the furnace.
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Atmospheric emissions, liquid wastes, and solid wastes are
generated by this process. The atmospheric emissions consisting of
gases, fumes, and dusts are generated throughout the process. The
process steps which are the major contributors are (1) charging of
the furnace, (2) melting of the charge, and (3) blowing of the
melt.
The composition of the emissions will vary depending on the
composition of the charge. Normally, the gases contain sulfur oxides,
nitrogen, carbon dioxide, and carbon monoxide. The particulate matter
includes fumes and dusts composed of such metal values as zinc, lead,
tin, copper, antimony, chlorine, unburned carbon, precious metals
(gold and silver), and constituents making up the fluxes.
Particle size of the fumes and dusts ranges from 0.05 micron
to approximately 1 micron for the fumes to approximately 5 microns or
greater for the dusts. The dusts are readily collected using such
devices as baghouses or electrostatic precipitators. Cyclones may be
used in conjunction with these. However, because of the small particle
size of the fumes, collection is difficult and much of the fumes pass
on through the control devices into the atmosphere.
Emissions data are lacking and it is difficult to even estimate
emission factors for this smelting process. However, it is estimated that
the furnace emissions factors may range from about 80 to about 450 Ib
of particulates per ton of scrap processed. These estimates are based on
the fact that the emission factor for smelting/refining in the brass and
bronze segment was estimated at approximately 80 Ib of particulates per
ton of alloy produced,(9) and emissions factor for similar processing in
the primary copper industry was estimated at approximately 450 Ib of
particulates per ton of copper produced.
Solid wastes and liquid wastes generated by this process are
the same wastes as generated by Processes 15 and 16. Data are lacking
(9) Spendlove, M. J., Methods for Producing Secondary Copper, U. S.
Dept. of Interior, Bureau of Mines, Information Circular 8002,
p 21 (1961).
(10) Vandegrift, A. E., et al., Particulate Pollutant System Study,
Volume III, Handbook of Emission Properties (pp 203,522), p 262
May 1, 1971).
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C-86
from which to calculate quantities. However, the slags contain such
metal values as zinc, tin, lead, copper, iron, alumina, silica, antimony,
and other nonvolatile metals present in the. scrap and the fluxes. Many
of the slags are recycled for copper recovery and the recovery of other
metal values before being discarded. Liquid wastes from cooling of the
equipment, quenching of the slags, and cooling of the ingots contain
both soluble and suspended solids. These wastes are recycled, disposed
of in settling ponds, or dumped into streams or sewers.
Thus, this process produces waste products which can cause
serious pollution problems if the wastes are not collected and disposed
of in a nonpolluting manner.
Refining/Casting Operation
Blister copper, black copper, and high grade copper scrap are
purified by the refining/casting operation. The products from this
operation containing approximately 99.9 percent copper are: (1) fire-
refined copper cast as ingots, billets, slabs, cakes, and bars for
manufacturing plates, sheets, rods, and copper base alloys; (2)
electrolytically refined copper cast as billets, wire bars, ingots, or
cakes; (3) O.F.H.C. copper (oxygen-free high conductivity copper); and
(4) copper powder. These are produced by Processes 18 through 25 as
shown in the copper segment flowsheet.
Fire-Refining Process (18). The final purification of scrap
copper may be achieved by the fire-refining process. The process steps
are: (a) charging the furnace which may be either a reverberatory or
cylindrical tilting type; (b) melting the charge in an oxidizing atmos-
phere until the melt begins to "work", i.e., begins to bubble and
liberate sulfur oxides; (c) skimming the melt; (d) blowing the melt with
air; (e) covering the melt with a reducing agent such as coke, charcoal,
or coal (anthracite); (f) poling with green wooden poles; (g) skimming,
if necessary; (h) pouring; and (i) casting into ingots, slabs, wire bars,
and-billets. In some cases, molten metal from the smelting operation is
charged directly to the reverberatory furnace. In regard to (f) above,
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the green poles used are largely maple and birch. They are approximately
10 inches in diameter at the base, at least 20 feet long, and weigh
approximately 200 Ib. Maple is preferred because it burns more slowly than
other woods. The quantity of green poles consumed varies depending on the
degree of reduction necessary. In the manufacture of wire bars from scrap
copper, approximately 100 Ib of poles per ton of copper are required.
As an alternative natural gas is being developed and in some cases may
be used in place of green poles.
Energy required for this process is that necessary to keep the
melt molten.
Atmospheric emissions, solid wastes, and liquid wastes are
produced by this process. Essentially each process step is a source of
atmospheric emissions which are composed of gases and particulate matter
made up of fumes and dusts.
Emissions data are lacking for the fire-refining process.
However, based on the chemistry involved and the composition of the
melt, the gases are known to contain sulfur oxides, carbon dioxide,
nitrogen, carbon monoxide, and most likely, hydrocarbons if green poles
are used, or ir-ethane if natural gas is used in the reduction phase of
the refining. The particulate emissions volatilized as fume or carried
from the furnace by entrainment in the gases contain such metal values
as zinc, tin, copper, lead, and others contained in the melt. In
addition, the emissions may also contain unburned carbon and materials
from the fluxing agents.
The atmospheric emissions are controlled with baghouses,
electrostatic precipitators, or wet scrubbers. A cyclone may be used
in conjunction with these devices.
Other wastes generated by the process are solid wastes and
liquid wastes. The solid wastes are slags containing the fluxing
materials and metal impurities from the black, blister, and scrap copper
and the impurities from the green poles. The liquid wastes are cooling
wastewater from cooling or quenching of the castings and cooling of the
furnace. The water contains soluble phosphate used to condition the
molds and the inhibitor from the cooling water.
(11) Schench, W. A., et al., Trans. AIME, Institute of Metals Division,
p 299 (1930).
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Although emission factor data are not available, this process
does generate large quantities of materials which can cause serious
atmospheric and water pollution problems.
Fire (Partial) Refining Process (19). When the copper is to
be cast into anodes, an intermediate product for electrolytic refining,
the melt is not completely fire-refined by oxidizing and poling. Instead,
the copper is partially fire-refined and cast into anodes. The anodes
contain about 99 percent copper and small amounts of silver, gold, lead,
selenium, tellurium, and other metals.
The process steps, energy required, pollutants generated,
emission factors, and control of pollutants are essentially the same
for this process as for the full fire-refining process, Process 18.
This process does generate significant quantities of potential
environmental pollutants and is, therefore, a source of potential
pollution problems.
Electrolytic Refining Process (20). Partial fire refined
copper--anodes--is converted to high purity copper cathodes by the
electrolytic refining process. The impurities in the anode copper
either dissolve in the electrolyte or fall to the bottom of the cells
as slime. The slimes may contain such impurities as sulfur, arsenic,
antimony, lead, nickel, selenium, tellurium, gold, and silver, if present
in the anode copper. The cathode copper assaying about 99.9+ percent
copper contains trace quantities of the above impurities and is the
intermediate product for Processes 21, 22, and 23 for the production of
electrolytic refined copper product and for the production of copper powder.
The process steps for the electrolytic refining process are:
(a) making up the electrolyte containing water, sulfuric acid, copper
sulfate, and addition agent; (b) placing the copper anode in the
electrolyte bath as one of the electrodes — the anode; (c) dissolving
the anode; (d) depositing the copper on the starting sheets — the cathode;
(e) removing the cathode for melting and casting; (f) regenerating the
spent electrolyte; and (g) removing slimes for recovery of metal values.
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Energy required for this process is electricity to produce
the cathodes and to drive the equipment.
This process produces essentially no atmospheric emissions
if the anode copper does not contain arsenic. If arsenic is present,
arsine (AsH_) is formed and evolved during electrolytic refining of
copper. This has not presented a serious problem for the operators as
the tank houses are generally well ventilated and the arsine is ejected
outside the house. However, arsine formation can be a problem in
electrolyte regeneration.
The major wastes produced are solid wastes (aqueous slurries
composed of the slime) and liquid wastes (spent electrolyte). The
slimes are sent to precious metal recovery where such metal values as
gold, silver, nickel, and lead are recovered. A "black liquor", liquid
waste, is formed during electrolyte purification. This material is
either discarded, generally after neutralization, or used in leaching
operations in associated plants. Additional liquid wastes are generated
during recovery of nickel, iron, zinc, and other metal values from the
spent electrolyte.
Thus, the electrolytic refining process can present serious
pollution problems. Arsine, an atmospheric pollutant which is volatile
and poisonous, is generated, if arsenic is present in the cathodes.
Furthermore, large quantities of liquid wastes and solid wastes are
generated which can cause water pollution problems.
Electric Melting Process (21). Cathode copper is melted and
cast into the desired shape by the electric melting process. Normally,
the process steps are: (a) feeding the cathodes into the furnace through
a charge slot to maintain a molten bath; (b) removing molten copper from
the tap hole; and (c) casting the molten copper as billets, wire bars,
ingots, or cakes. Periodically, flux is added to the melt to refine
the copper and slag is removed as the waste product.
Energy required is the electricity to melt the copper and
drive the auxiliary equipment.
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C-90
Wastes generated by this process are small amounts of
atmospheric emissions, liquid wastes, and solid wastes. The atmospheric
emissions result primarily from the evolution of gases from the melting
operation and from pouring and casting of the pure copper. The solid
wastes are the slags or skimmings from the melting furnace, whereas
liquid wastes are formed during ingot casting and cooling of the
equipment.
Emissions data are not available for this process. It is
expected that this process would constitute a minor source of pollution
problems in this segment of the secondary nonferrous metals industry.
Reverberatory Melting Process (22). This process is an
alternative process for converting cathode copper intermediate product
to the desired shapes of electrolytic refined copper. The process steps
are: (a) charging the reverberatory furnace, (b) melting the cathodes,
(c) blowing (flapping) of melt, (d) skimming of melt, (e) poling of
melt, (f) skimming of melt, (g) pouring, and (h) casting.
Energy required is the fuel to melt and keep the charge molten
and that required to drive the auxiliary equipment.
Atmospheric emissions, liquid wastes, and solid wastes are
produced by this process. The atmospheric emissions—gases, fumes,
and dusts--are formed during each processing step with the majority of
the emissions being evolved during blowing (flapping) and poling of the
melt. Emissions data are not available on the quantity and composition
of these emissions; however, it is expected that the emissions contain
gases such as carbon dioxide, carbon monoxide, sulfur oxides, and
hydrocarbons. The fumes and dusts are composed of, primarily, copper,
and small quantities of such metal values as lead, nickel, selenium,
and tellurium.
Liquid wastes result from casting of the melt into the desired
shapes and from cooling of the equipment. These liquid wastes, primarily
wastewater, contain soluble inhibitors and insoluble solids such as the
bone ash to condition the molds. In some cases, phosphates may be used.
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Solid wastes are the slags or skimmings formed and removed
from the melt during the melting (refining) of the cathodes. These
wastes contain the impurities from the cathode copper and the fluxes,
if added.
In view of the waste products and emissions generated by this
process, pollution problems can result if these pollutants are not
collected and disposed of in a nonpolluting manner. However, it is
expected that this process is a minor source of pollution problems
when compared to some of the other processes.
Induction Melting Process (23). Oxygen-free-high-conductivity
(O.F.H.C.) copper is produced by the induction melting process using
cathodes as the source of copper. The O.F.H.C. copper is oxygen-free
with a reported purity of 99.99 percent. The process steps are:
(a) clean the cathodes, (b) preheat the cathodes in an atmosphere of
reducing gas which is low in hydrogen, (c) melt the clean, preheated
cathodes in a low-frequency induction heater, (d) cover the melt with
graphite granules, (e) discharge molten copper to a low-frequency
induction-heated "pour hearth" which distributes the copper to the
casting machine, and (f) cast the O.F.H.C.* copper. A nonoxidizing
atmosphere is maintained throughout melting and casting.
Energy required is the electricity to melt the cathodes and
keep the melt molten and to operate the auxiliary equipment.-
Waste products produced by this process are atmospheric
emissions, solid wastes, and liquid wastes. The atmospheric emissions
are produced during preheating of the cleaned cathodes, melting of the
cathodes, and casting of the copper melt into ingots and other shapes.
Emissions data are not available; however, the emissions no doubt consist
of reducing gases and carbon monoxide from melting of the cathodes. The
gases contain a small quantity of particulate matter which is composed
of copper along with other metals found in the melt and graphite particles,
The solid waste is basically graphite used to cover the melt. The liquid
wastes are wastewater used in the casting of the melt and cooling of the
equipment.
* O.F.H.C. is a trade name of the U. S. Metals Refining Company and
also means oxygen free high purity copper.
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This process produces minor quantities of potential
environmental pollutants. Therefore, the process has little or no
potential for producing serious pollution problems.
.Electrolytic Winning Process (24). Copper in the form of
impure copper cathode, an intermediate product to electrolytic refining
process, is recovered from copper sulfate solutions by the electrolytic
winning process. The deposit is not as pure as the cathodes from the
electrolytic refining process and, therefore, must be purified. The
process steps are: (a) prepare electrolyte, (b) electrolytically
deposit the copper on thin copper starter sheets, (c) remove the copper
cathodes from the electrolytic cells, (d) clean cathodes by soaking in
water, (e) replace copper starter strips, (f) regenerate electrolyte,
and (g) repeat series of above steps. Spent electrolyte is is con-
tinuously bled from the system, regenerated, and returned.
Energy required is the electricity to operate the process.
The waste products generated by the process are primarily
liquid waste consisting of spent electrolyte and solid wastes consisting
of slimes formed during the electrolysis and resulting from regeneration
of the electrolyte. If the electrolyte contains arsenic, gaseous arsine
(AsH-j) is liberated. This material is generally vented to outside of
the building.
Emissions data are lacking. However, from data which are
available on electrolytic refining, most likely, the waste products
produced by the electrolytic refining process can cause water pollution
problems.
Electrolytic Powder Production Process (25). Copper powder
is prepared from copper sulfate solutions by the electrolytic powder
production process using pure copper cathodes from the electrolytic
refining process as the source of copper. The process steps are:
(a) prepare electrolytic cell for powder production using cathode
copper as the anode, (b) electrolytically deposit copper powder,
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C-93
(c) remove copper powder from cell, (d) return electrolyte to cell,
(e) wash electrolyte from copper powder, (f) heat powder in hydrogen-
carbon monoxide atmosphere to remove water, (g) classify dried powder,
(h) blend powders of different particle size to obtain correct particle
size distribution, and (i) package product.
Energy required is the electricity to produce the copper
powder and drive the equipment and the fuel to heat the dryer.
Waste products produced by this process are atmospheric
emissions and liquid wastes. The atmospheric emissions contain gases
composed of water vapor, carbon monoxide, hydrogen, possibly arsine,
and unburned fuel. The particulate portion of the atmospheric emissions
is copper powder from the dryer, blender, and classifier.
The liquid waste is the spent electrolyte from the electrolytic
cell and wash liquor from washing the copper powder. The spent liquor
is normally regenerated and recycled to the electrolytic cell. The
wash liquor containing sulfuric acid, water, and some soluble copper
is probably neutralized and disposed of in a holding pond.
Thus, waste products produced by this process can cause
pollution problems if not properly controlled.
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Population of Secondary Copper Processors
(1) Earth Smelting Corporation
99-129 Chapel Street
Newark, New Jersey
Telephone: (201) MA2-4908
(2) Batchelder-Blasius, Inc.
Post Office Box 5503
Spartanburg, South Carolina
29301
Telephone: (803) 439-6321
(3) Bay State Refining, Inc.
Chicopee Falls, Massachusetts
(4) Joseph Behr and Sons, Inc.
1100 Seminary Street
Rockford, Illinois
Telephone: (815) 962-7721
(5) Belmont Smelting and Refining
Works, Inc.
320 Belmont Avenue
Brooklyn, New York
Telephone: DI2-4900
(6) W. J. Bullock, Inc.
Post Office Box 539
Fairfield, Alabama
(7) Cerro Corporate Brass Company
Division of Cerro Corporation
16600 St. Clair Avenue
Cleveland, Ohio 44110
Telephone: (216) 481-3000
(8) Circuit Foil Corporation
23 Amboy Road
Bordentv)v;, New Jersey
Telephone: (609) 298-4800
(9) Colonial Metals Company
Columbia, Pennsylvania
Telephone: (717) 684-2311
(10) General Copper and Brass Company
Post Office Box 5353-D
• Philadelphia, Pennsylvania
Telephone: SA6-7111
(11) Samuel Greenfield Company,
Inc.
Stone and Ingot Streets
Brooklyn, New York
(12) Holstead Metal Parts, Inc.
West Newcastle Street
Zelienople, Pennsylvania
16063
Telephone: (412) 452-6500
(13) Benjamin Harris & Company
Eleventh and State Streets
Chicago Heights, Illinois
Telephone: SK5-0573
(14) Henning Brothers & Smith,
Inc.
91-115 Scott Avenue
Brooklyn, New York
(15) K. Hettleman & Sons,
Division of Minerals and
Chemicals
Phillip Corporation
Ninth Street and Patapsco
Avenue
Baltimore, Maryland 21225
Telephone: (301) 355-0770
(16) Holtzman Metal Company
5223 McKissock Avenue
St. Louis, Missouri 63147
(17) H. Kramer & Company
1339-59 West 21st Street
Chicago, Illinois 60608
Telephone: CA6-6600
(18) Metal Bank of America, Inc.
6801 State Road
Philadelphia, Pennsylvania
19135
Telephone: (215) 332-6600
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C-95
(19) Nassau Smelting and Refining Co.,
Inc.
5 Nassau Place
Tottenville, New York
Telephone: (212) YU4-1970
(20) Phelps Dodge Refining
Corporation
300 Park Avenue
New York, New York
Telephone: 751-3200
(21) Riverside Alloy Metal Division
H. K. Porter Company, Inc.
309 Porter Building
Pittsburgh, Pennsylvania 15219
Telephone: (412) 391-1800
(22) Roessing Bronze Company
320 Barbour
Pittsburgh, Pennsylvania
(23) I. Schumann & Company
4391 Bradley Road
Post Office Box 2219
Cleveland, Ohio
(24) M. Seligman & Company
3401 S. Lawndale Avenue
Chicago, Illinois
(25) SIPI Metals Corporation
1722 N. Elston Avenue
Chicago, Illinois
(26) U. S. Metals Refining Company
1217 Avenue of Americas
New York, New York 10020
Telephone: (212) PL7-9700
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SCRAP PRE TREATMENT
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-------
C-97
PROCESS DESCRIPTION OF THE GERMANIUM SEGMENT OF
THE SECONDARY NONFERROUS METALS INDUSTRY
Annual production volume of secondary germanium is about 8000
pounds. Because of the high cost of germanium (~$50/lb), process losses
through air, solid waste, and water emissions are reduced to a minimum.
Also, the emphasis placed on the highest possible purity of the final
product insures that all processing operations are conducted in closed
systems to prevent atmospheric contamination of the product.
Raw Materials
Germanium scrap sources are as follows:
(1) Solid scrap (100 percent solid metal) obtained as
scrap ends from zone refining
(2) Slicing compounds from single crystals obtained
as sludge containing 50 to 80 percent germanium
(3) Acid etching scrap
(4) Grindings and polishing wastes from the infrared
industry
(5) Scrap from the electronic industry.
Products
High purity germanium is the only product of this segment.
Process Description
One manufacturing operation—hydroraetallurgical refining—is
involved in the processing of germanium scrap. This operation and the
processes involved in it are shown in the process flowsheet of this
segment.
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C-98
Hydrometallurgical Refining Manufacturing Operation
This operation Involves three processes—chlorination, hydrolysis,
and hydrogen reduction. These are discussed in detail below.
Chlorination Process (1). In this process, germanium is converted
to germanium tetrachloride. The process steps are (1) charge scrap to
vessel, (2) heat and add sodium chloride.
The volatilized tetrachloride with any impurities is distilled
to get germanium tetrachloride.
The process requires minor amounts of heat energy.
Small quantities of gaseous wastes are generated.
The emissions are water scrubbed and the solids recycled.
Scrubber water is also recycled.
The process has no significant pollution potential.
Hydrolysis Process (2). This process converts the tetrachloride
to germanium dioxide by ice water hydrolysis.
Details of the process steps are not known.
Minor amounts of water waste (with insignificant pollution
potential) are generated.
Hydrogen Reduction Process (3). This process converts the
germanium dioxide to the pure metal.
The process steps are (1) pass hydrogen, (2) heat to 650 C.
Heat energy is utilized in this process.
The process produces no pollutants.
Population of Secondary Germanium Processors
(1) Belmont Smelting and Refining Works (2) Kawecki Berylco Industries
320 Belmont Avenue (KBI)
Brooklyn, New York 220 East 42nd Street
New York, New York 10017
(212) 682-7143.
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8 7 | 6 | 5 4 3
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C-100
PROCESS DESCRIPTION OF THE HAFNIUN SEGMENT
OF THE SECONDARY NONFERROUS METALS INDUSTRY
Since hafnium occurs in nature with zirconium, both hafnium
and zirconium are processed and isolated in the same facility. The quantity
of hafnium marketed in the U. S. is very small (less than a million ounces).
Hafnium is not a toxic metal. Due to the high unit price of the
metal, recovery is maximized by excellent waste control.
These considerations indicate the environmental pollution problems
from the secondary hafnium industry are insignificant.
Details of the process are difficult to obtain because of the
desire of the U. S. hafnium processors to protect the proprietary nature
of their process.
Population of Secondary Hafnium Processors
(1) Amax Speciality Metals Division
American Metal Climan, Inc.
6000 Hake Road
Akron, New York 14001
Telephone: (716) 542-5454
(2) Teledyne Wah Chang
P. 0. Box 460-T
Albany, Oregon
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C-101
PROCESS DESCRIPTION OF THE INDIUM SEGMENT
OF THE SECONDARY NONFERROUS METALS INDUSTRY
Efforts to obtain information on this segment have not been
as successful as in other areas. The Indium Corporation of America is
the only producer of secondary indium and information obtained from this
company is summarized below.
(1) The total annual U. S. production (1972) of both
primary and secondary indium is less than 2 million
ounces (<62 tons). The market value of indium is
about $4.50 per ounce. This high cost of indium makes
the recovery process very profitable and necessary.
(2) The process of recovery of indium consists of using
a small blast furnace followed by a series of typical
chemical and electrical recovery processes, details
of which are proprietary.
(3) Indium is not toxic. There are no environmental
problems or emissions.
(4) The industry is not interested in any external
assistance in research and development work. The
entire process is proprietary. The industry is
very careful to protect that status.
Population of Secondary Indium Processors
The Indium Corporation of America
1676-1680 Lincoln Avenue
Utica, New York 13502
Telephone: (315) 797-1630
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C-102
PROCESS DESCRIPTION OF THE LEAD SEGMENT OF
THE SECONDARY NONFERROUS METALS INDUSTRY
Introduction
This segment of the secondary nonferrous metals industry
ranks second in consumption of scrap materials. In 1971, 784,700
tons of lead scrap were consumed. In the recovery of the lead value
from scrap, waste products are generated in the form of atmospheric
emissions, liquid wastes, and solid wastes. These materials can cause
pollution problems.
Raw Materials
(2)
The principal sources of lead scrap are:
Soft lead
Hard lead
Cable lead
Battery-lead plates
Mixed common babbits
Solder and tinny lead
Type metals
Drosses and residues.
New scrap in the form of purchased drosses and residues make up 18 percent
(143,400 tons) of the total. The remainder, old scrap, is predominantly
battery scrap with small amounts of the other scrap. The scrap is
essentially all from domestic sources. In addition to containing metallic
lead or compounds and alloys of lead, the scrap contains a variety of
organic materials such insulation, grease, and oil. Common alloying
(1) Ryan, J. P., Minerals Yearbook, U. S. Dept. of Interior, Bureau of
Mines, Vol. I, p 671 (1973).
(2) ibid, p 683 (1973).
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C-103
agents found in the scrap are tin, antimony, arsenic, cadmium, copper,
indium, silver, zinc, tellurium, and bismuth.
Products
Products from the lead segment of the secondary nonferrous
metals industry are: (1) lead ingots (pure/soft), (2) lead ingots
(hard/semisoft), (3) lead ingots (alloys), (4) lead oxide (battery
lead oxide), and (5) lead pigments (Pb3<>4 and PbO).
Process Description
Lead is recovered from lead scrap by three manufacturing
operations: (1) scrap pretreatment, (2) smelting, and (3) refining/
casting. These operations and the processes associated with each
operation are shown in the flowsheet entitled "Lead Segment of the
Secondary Nonferrous Metals -Industry".
Scrap Pretreatment Operation
In this operation, the lead scrap is treated to make it more
amenable to further processing. This treatment involves densification
and/or partial removal of metallic and nonmetallic contaminants.
Battery Breaker Process (1). The major source of lead is
obsolete automobile batteries. By this process, the lead is separated
from the nonmetallic portion of the battery. The process steps are:
(a) draining the battery if not received dry, (b) breaking (crushing)
the battery to break the lead portion from the nonlead portion, and
(c) separating the lead from the battery case. This lead scrap in this
form can be fed into the reverberatory or blast furnace for further
processing and recovery of the lead.
Energy required for this process is that to drive the
equipment.
-------
C-104
Waste products generated are primarily liquid wastes and
solid wastes. A small quantity of dusts may be generated if the
batteries are treated dry. These dusts are composed of dirt, plastic,
or battery case materials and lead compounds such as lead oxide and
lead sulfate.
The liquid wastes are composed of sulfur acid, water, lead
compounds, and the alloying agents from the lead plates.
The solid wastes, which make up the bulk of the waste products
from this process are composed of the organic materials used in battery
case fabrication. In addition, these solid wastes contain some sulfuric
acid and lead compounds.
In view of the waste products generated by this process,
serious pollution problems can arise if the wastes are not disposed of
in a nonpolluting manner.
Crushing Process (2). Much of the drosses, residues, and
possibly slags are received in large pieces, i.e., larger than desired
for further processing. These scrap materials are crushed with jaw
crushers to a suitable size. The process steps are: (a) load the
crusher and (b) crush the scrap. Afterwards, the scrap is removed and
further processed to recover the lead content.
Energy required is limited to that necessary to drive the
equipment.
Waste products from this process are dusts resulting from
the handling and crushing of the scrap.
Emissions data are not available. However, significant
quantity of emissions could be generated. Therefore, the process can
present pollution problems, if the dusts are not collected.
Rotary/Tube Sweating Process (3). Lead sheathed cable and
wire, aircraft tooling dies, type metal drosses, and lead dross and
skimmings are treated by the rotary/tube sweating process to recover
the lead value. The process steps are: (a) charge the furnace with
the scrap, (b) melt the lead value, (c) collect the molten lead,
-------
C-105
(d) cast the molten lead, and (e) remove the residue from the
furnace.
Energy required for this process is the fuel to heat the
rotary furnace or sweating tube and electricity to drive the equipment.
Atmospheric emissions and solid wastes are generated by this
process. The emissions contain gases composed of sulfur oxides,
entrained air, nitrogen oxides, and the fuel combustion products.
The particulate portion of the atmospheric emissions is composed of
fumes, dusts, unburned fuel, soot, and fly ash. Furnace atmospheric
emissions data are not available. However, based on data from similar
processes, emissions factors are estimated to range from 70 Ib of
particulates per ton of metal processed (raw emissions factor for rotary
reverberatory furnace smelting of lead) to 32 Ib of particulates
per ton of scrap processed^ ' (raw emissions factor for sweating of
residual zinc).
Particle size of the emissions varies. The larger particles
(dusts) are probably in the 5 to 20 micron or larger range, whereas
the unagglomerated lead fumes vary in diameter from 0.07 to 0.4 micron
with a mean particle size of 0.3 micron.
Solid wastes are the metallic and nonmetallic portion of the
scrap after removal of the lead.
As significant quantities of atmospheric emissions and solid
wastes are generated by this process and since lead and lead compounds
are toxic or hazardous materials, the waste products from this process
can cause serious pollution problems if the waste products are not
controlled. Failure to control the atmospheric emissions can result
in pollution of the atmosphere, whereas disposal of the solid wastes in
an unapproved manner can result in water pollution.
(3) Vandegrift, et al., Particulate Pollutant System Study, Vol. Ill,
Handbook of Emission Properties, Midwest Research Institute,
Kansas City, Missouri, p 406 (May 1, 1971).
(4) Herring, W. 0., Secondary Zinc Industry, Emission Control Problem
Definition Study, APCO, EPA, Durham, North Carolina, p Vl-22.
(5) Air Pollution Engineering Manual, U. S. Dept. HEW, NCAPA,
Cincinnati, Ohio, p 307 (1967).
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C-L06
Reverberatory Sweating Process (4). This process is normally
used to sweat scrap containing high lead content such as lead battery
plates. The process steps are the same as for Process 3.
Energy required is the fuel--gas or oil--to heat the furnace.
Waste products from this process are atmospheric emissions
and solid wastes. The atmospheric emissions are composed of gases and
particulate matter containing both fumes and dusts. The gases discharged
from the furnace contain the combustion products, sulfur oxides, unburned
fuel, and hydrocarbons from pyrolysis of the organic compounds present in
the scrap. The fumes and dusts contain metallic materials such as lead,
antimony, and other heavy metals used to prepare the lead alloys, and
nonmetallic materials such the fluxes and carbon or other organic
contaminants from the scrap.
Although emissions data are lacking, it is estimated based on
data from similar processes that raw emissions factor for the reverberatory
sweating process will range from approximately 30 Ib per ton of charge
{3 4)
to 70 Ib per ton of metal processed. '
Unagglomerated lead oxide fume particles vary in diameter
from 0.07 to 0.04 micron with a mean diameter of about 0.3 micron.
The particle size of the dust is expected to be much larger, normally
in the 5 to 20 micron or larger size range.
The atmospheric emissions are controlled by the same
system as is used for the smelting operation and discussed under
Process 5.
Solid waste materials are the residues remaining after removal
of the lead. Composition of these wastes may vary somewhat, but
generally will contain lead and other heavy metals such as antimony.
This process has a high potential for the production of
pollution problems if emissions are not controlled.
Smelting Operation
Pretreated scrap is partially refined, i.e., some of the
metallic and nonmetallic contaminants are removed by the smelting
-------
C-107
operation. The individual processes (5 and 6) comprising the smelting
operation are shown in the attached flowsheet.
Reverberatory Smelting Process (5). Lead scrap (pretreated
or untreated, mixed) is partially purified and densified by the reverber-
atory smelting process. This is achieved by the following process steps:
(a) charge the furnace with the lead scrap and flue dusts, (b) melt the
scrap, (c) allow the antimonical slag to rise to the surface of the melt,
(d) tap the antimonical slag to the blast furnace, and (e) tap the molten
lead melt to the refining/casting operation. Alternately, the molten lead
may be poured and cast into ingots as a semisoft/hard lead product.
The energy required for this step is from the fuel oil or gas to
smelt the scrap.
Atmospheric emissions are produced by this process. 'No solid
or liquid wastes are produced.
The atmospheric emissions are composed of gases and particulate
matter. The gases contain the products from combustion of the fuel and
sulfur oxides along with any other gases from the scrap. The particulate
matter (fume) is composed of oxides, sulfides, and sulfates of lead, tin,
arsenic, copper, and antimony. Recoverable lead from the charge is about
47 percent. Approximately 46 percent of the charge is slag and 7 percent
is fumes and dusts.
The unagglomerated particulate matter was found to have a
particle size range of 0.07 to 0.4 micron with a mean value of 0.3 micron.
The particle shape was essentially spherical.
The reverberatory smelting process accounts for approximately
75 percent of the emissions from the lead segment of the secondary
nonferrous metals industry. Particulate emission factor for reverberatory
smelting is estimated at 130 Ib (uncontrolled) and 1.6 Ib (controlled)
per ton of metal processed. Raw sulfur oxide emission factor is estimated
(6) Air Pollution Engineering Manual, U. S. Dept. HEW, NCAPC,
Cincinnati, Ohio, pp 301-302 (1967).
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C-108
at 85.(/7>8>9) ID to 190^10^ Ib per ton of metal processed.
Particulate emissions from this process are controlled with
a baghouse, scrubber, or both. The baghouse is aorranged as the final
collector. These systems also include auxiliary items such as gas
cooling devices and settling chambers. Sulfur oxide emissions are
controlled in some plants with a wet scrubber.
The process produces significant quantities of atmospheric
emissions and is, therefore, a potential source of pollution problems.
Blast Furnace Smelting Process (6). Semisoft/hard lead
which is a product and an intermediate product, is produced from
pretreated scrap, antimonical slag (reverberatory slag), and rerun slag
by the blast furnace smelting process. In this process the molten lead
flows almost continuously and the slag is tapped at intervals. A '
typical charge which is added as the material melts down is: 4.5 percent
scrap iron; 3 percent limestone; 5.5 percent coke; and 82.5 percent
drosses, oxides, and reverberatory slag. The drosses are miscellaneous
drosses consisting of copper drosses, caustic dross, and dry drosses from
the refining process in the pot furnace. Thus, the process steps are:
(a) add the charge with a composition as noted above, (b) continuously
remove the molten lead, (c) remove the slag at intervals, and (d) cast
the lead ingots or transfer molten lead to the refining kettles.
The energy utilized in this process is from coke, which also serves
as a reducing agent.
Waste products produced by this process are atmospheric emissions
and solid wastes. The atmospheric emissions consist of gases containing
carbon monoxide, hydrocarbons, sulfur oxides, nitrogen oxides, and probably
(7) Nance, J. T., and K. 0., Luedtke, Lead Refining, Air Pollution
Engineering Manual, Danielson, J. A. (ed), U. S. DHEW, PHS, National
Center for Air Pollution Control, Cincinnati, Ohio, Pub. No.
999-AP-40, pp 300-304 (1967).
(8) Allen, G. L., et al., Control of Metallurgical and Mineral Dusts and
Fumes in Los Angeles County, Dept. of the Interior, Bureau of Mines,
Washington, D. C., Information Circular No. 7627, April, 1952.
(9) Hammond, W. F., Data on Nonferrous Metallurgical Operations, Los
Angeles County Air Pollution Control District, November, 1966.
(10) Unpublished work, Battelle's Columbus Laboratories (1972).
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C-109
nitrogen. The particulate matter in the emissions contains oil vapor,
smoke, fume, and dust. The fume and dust are composed of lead, tin, zinc,
coke dust, sulfur, and other metals contained in the charge. The fumes
are volatized and condensed from the charge, whereas the dusts are carried
from the furnace by entrainment in the furnace gases.
Particle morphology of the particulate emissions are similar to
those from the reverberatory furnace. Particle size ranges from 0 to 16
microns with approximately 15 percent between 0 to 1 micron, 45 percent
between 1 to 2 microns, 20 percent between 2 to 3 microns, 15 percent
between 3 to 4 microns, and 10 percent between 4 to 16 microns . No
data are available on particle shape; however, the dust is most likely
irregular and the fume (smaller size) is spherical.
Emissions rate is high from the blast furnace smelting process.
Raw particulate emissions factor (uncontrolled) is estimated at'190 Ib per
ton of metal processed. Sulfur oxide emissions factor is estimated at 90
(12 )
Ib per ton of metal processed. ' Controlled emissions factors are 2.3
and 0.8 to 46 Ib per ton of metal processed, respectively.
The emissions are subject to control. The baghouse is the most
acceptable device for controlling the particulate emissions. The gas
stream containing the emissions is first passed through a series of water
or air cooled tubes and then to the baghouse. To prevent tar volatiles
from blinding the bags, the temperature of the baghouse is kept high.
Lime is also added to the gas stream to prevent the blinding action. The
gas stream from the baghouse is discharged to a stack or possibly to an
electrostatic precipitator in an attempt to further clean the gases before
(13)
emitting them to the atmosphere.
(11) Air Pollution Engineering Manual, U. S. Dept. HEW, NCAPC,
Cincinnati, Ohio, p 303 (1967).
(12) Compilation of Air Pollutants Emission Factors, 2nd Ed., U. S.
EPA, Office of Air and Water Programs, Research Triangle Park,
North Carolina, p 7.11-2 (April, 1973).
(13) U. S. Dept. of Commerce, Economic Impact of Air Pollution Controls
on the Secondary Nonferrous Metals Industry, Washington, D. C.,
p 132 (1969).
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C-110
Wet scrubbers may be employed to clean the gaseous portion of
the stream. The caustic (NaOH) scrubber is more effective than the water
spray chamber for removing sulfur oxides as.evidenced by the fact that
caustic scrubbing reduced the emissions factor from 90 Ib per ton of metal
processed to 0.8 Ib per ton of metal processed, whereas water scrubbing
(14)
reduced the emission factor to only 46 Ib per ton of metal processed.
Solid wastes from this process are the baghouse and flue dusts
and fumes, and the slag. For the most part, these are recycled to the
process because of the high lead content.
Thus, uncontrolled, the blast furnacing process produces large
quantities of atmospheric emissions and solid wastes which can cause serious
pollution problems, both from the atmospheric and water pollution aspects.
Refining/Casting Operation
The intermediate products from the reverberatory and blast furnace
processes--soft lead and antimonical lead--required additional purification
or refining to produce the desired products. In addition to the metal
products, some of the lead is converted to lead oxide products. The
processes employed to achieve conversion of the impure lead intermediate
products to the final products are processes 7 through 11 as shown in
the attached flowsheet.
Kettle (Softening) Refining Process (7). The intermediate
products from the smelting operation may contain copper (generally not
present) and antimony which makes the lead hard. Removal of these two
contaminants by the kettle (softening) refining process produces soft
lead--one of the products from the lead segment of secondary nonferrous
metals industry. The process steps are: (a) charge the preheated kettle,
(b) melt the charge, (c) stir the molten charge to mix in the flux, (d)
remove the skimmings, (e) pour the molten metal, and (f) cast into ingots
(bullion). In some cases, the molten lead is poured directly from the
smelting operation to the refining kettle.
(14) Compilation of Air Pollutant Emission Factors, 2nd Ed., U. S. EPA,
Research Triangle Park, North Carolina, p 7.11-2 (April, 1973).
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C-lll
Several fluxes or purifiers are used. Included in this list
are sodium hydroxide, sodium nitrate, aluminum chloride, or aluminum.
Air is occasionally used to blow the melt.
Source of energy for this process is generally gas to heat
the kettle indirectly and electricity to drive the equipment.
Waste products produced are atmospheric emissions and solid
wastes (skimmings). The atmospheric emissions containing mainly fumes
and possibly some dust are composed of such metals as lead, antimony,
sodium, and trace quantities of copper, zinc, arsenic, bismuth, and tin.
The gaseous portion of the emissions contains primarily the fuel
combustion gases.
Particle morphology should be similar to the fumes from the
reverberatory smelting process, i.e., the particle size is in the
submicron range and the shape is generally spherical.
Although the quantity of emissions from the refining process
is much less than from the other lead processes, for example, 0.8 lb
of particulates "per ton of metal processed as compared to 190 lb per ton
of metal processed for reverberatory smelting, the toxic or hazardous
nature of lead requires that the emissions be controlled. The
most widely used device is the baghouse. The fumes are collected via
a hood over the kettle.
The solid wastes are skimmings containing the flux and
other metal values removed from the melt during the refining operation.
These wastes along with the particulate matter from the baghouse are
generally recycled to the blast furnace for recovery of the lead value.
Thus, the kettle (softening) refining process produces waste
products which can cause pollution problems, if wastes are not collected
and disposed of in a nonpolluting manner.
Kettle (Alloy) Refining Process (8). Kettle (alloy) refining
process involves treatment and adjustment of the metals content of lead
to produce the desired lead alloy. This involves the following process
(15) Blythe, D. J., Ed., "Lead and Arsenic Reports", Journal of the
Air Pollution Control Association, 10 (5), p 940-944 (1955).
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C-112
steps: (a) charging the preheated kettle, (b) melting the charge,
if not added molten, (c) stirring to mix the flux into the charge,
(d) skimming to remove collected impurities, (e) pouring, and (f) casting.
Alloying agents commonly used are antimony, copper, silver, and tin.
Source of energy for this process is natural gas and electricity
to drive the equipment.
Emissions data—waste products produced, emissions factor,
control of emissions, and particle morphology—are essentially the same
for this process as for Process 7.
Thus, the process can be a source of environmental pollution.
Kettle Oxidation Process (9). Battery lead oxide (PbO
containing approximately 20 percent lead metal) is produced by the
kettle oxidation process. The process steps are: (a) charge kettle
with molten lead from a melting pot, (b) rapidly agitate (mechanically)
the lead, (c) draw air over the surface of the melt through the duct
leading to the baghouse, and (d) collect the lead oxide (fumed from the
surface of the melt) in the baghouse.
Source of energy is natural gas to heat the melt furnace and
the oxidation furnace, and electricity to drive the equipment.
Atmospheric emissions are produced by'this process. These
include (1) the combustion gases which are separate from those from the
melting chamber, oxidation chamber, and the baghouse; and (2) fumes and
dust from the melting and oxidation chambers and the baghouse. The gases
are composed of carbon dioxide, carbon monoxide, sulfur oxides, nitrogen
oxides, and unburned fuel, whereas the particulate matter contains lead
oxide, lead metal, and other metal values from the melting and oxidation
chambers and the baghouse.
The major source of emissions is the baghouse since the air
is being swept over the oxidation chamber into the baghouse. Emission
factor for the baghouse will vary somewhat, but in most oxide collection
systems, collection efficiency averages greater than 98 percent. On this
basis, emissions factor is estimated at less than 40 Ib of lead oxide
per ton of oxide produced. Particle size of the oxide is in the submicron
range (approximately 0.2 to 0.5 micron) and particle shape is spherical.
-------
0113
Thus, the kettle oxidation process is a source of pollution
problems.
Reverberatory Oxidation Process (10). The most widely used
lead oxide pigments are lead monoxide (PbO) and red lead (Pb-0,). These
are produced by the reverberatory oxidation process. The process steps
are: (a) charge the hot reverberatory furnace with molten lead,
(b) agitate the melt while oxidizing the lead to lead oxide, and
(c) remove the lead oxide from the furnace and cool rapidly. Lead
oxide (PbO) is produced by fully oxidizing the lead, whereas red lead
(Pb_0.) is produced by over-oxidizing the PbO.
Energy required for this process is from the fuel (natural
gas or fuel oil) to heat the furnace.
Waste products produced by this process are atmospheric
emissions. These emissions are gases containing the combustion gases,
excess air, and nitrogen and particulate matter containing lead oxide
along with the impurities found in the lead charge. These emissions
are carried from the furnace by entrainment in the furnace gases or
from volatilization and condensation of the lead oxide fumes. Particle
size is in the submicron range and the particles are spherical in shape.
Emissions data are not available for the reverberatory
oxidation process. However, it is estimated that the emission factor
will range from approximately 40 to 150 Ib per ton of lead oxide
produced. These emissions are most likely controlled by a baghouse.
Thus, the reverberatory oxidation process for producing lead
oxides can be a source of serious pollution problems.
-------
C-114
Population of Secondary Lead Processors
(1) Abrams Waste Materials Company
1421 S. McBride Street
Syracuse, New York
(2) Allie Smelting Corporation
5116 W. Lincoln Avenue
Milwaukee, Wisconsin 53219
Telephone: (414) 541-7830
(3) Cambridge Smelting Company
100 Pacific Street
Cambridge, Massachusetts
(4) Chicago Smelting and Refining Co.
3701 S. Kedzie Avenue
Chicago, Illinois
(5) Colinial Metals Company
Columbia, Pennsylvania
Telephone: (717) 684-2311
(6) Crown Metal Company
123 E. Washington
Milwaukee, Wisconsin
(7) Detroit Lead Pipe Works, Inc.
1701 Linden Avenue
Detroit, Michigan
(8) Electric Storage Battery Company
2 Penn Central Plaza
Philadelphia, Pennsylvania
Telephone: (215) 564-4030
(9) Florida Smelting Company
2640 Capitola Street
Jacksonville, Florida
Telephone: (904) 353-4317
(10) General Battery and Ceramic
Corporation
. Post Office Box 1262
Reading, Pennsylvania
(11) Industrial Metal Smelting Co.
1508 Open Street
.. Baltimore, Maryland
(12) Industrial Smelting Company
19430 Mt. Elliott & Marx Sts.
Detroit, Michigan
(13) Inland Metals Refining Company
651 E. 119th Street
Chicago, Illinois 60628
(14) Lead Products, Inc.
Manchester, Connecticut
(15) Nassau Smelting and Refining
Company, Inc.
5 Nassau Place
Tottenville, New York
Telephone (212) 984-1970
(16) National Lead Company
111 Broadway
New York, New York 10006
Telephone: (212) 732-9400
(17) North American Smelting Company
Terminal (P. 0. Box 1952)
Wilmington, Delaware
Telephone: (302) 654-9901
(18) Price Battery Corporation
942 Grand Street
Hamburg, Pennsylvania
(19) Rochester Lead Works, Inc.
Exchange and Ewell Sts.
Rochester, New York
(20) Schuylkill Products Co, Inc.
Post Office Box 3916
Baton Rouge, Louisiana
Telephone: (504) 775-3040
(21) Seitzinger's Inc.
Post Office Box 1336
Atlanta, Georgia
Telephone: (404) 876-3787
(22) Southern Lead Company
2823 NW Moreland Road
Post Office Box 6195
Dallas, Texas
Telephone: (214) 331-3241
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C-115
(23) U. S. Smelting Works
American and Bristol Streets
Philadelphia, Pennsylvania
(24) U. S. Lead Refinery, Inc.
5300 Kennedy Avenue
East Chicago, Indiana
Telephone: (219) 397-1012
(25) Hyman Viener & Sons
Richmond, Virginia 23205
Telephone: (703) 648-6563
(26) Wenesley Metal Products Company
1415 Osage
Denver, Colorado
(27) Western Lead Parts Company
City of Industry, California
(28) Willard Smelting Company
101 E. New Bern
Charlotte, North Carolina
(29) Winston Lead Smelting Company
Winston-Salem, North Carolina
-------
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C-L17
PROCESS DESCRIPTION OF THE MAGNESIUM SEGMENT
OF SECONDARY NONFERROUS METALS INDUSTRY
Magnesium recovered from scrap constitutes approximately
10 percent of the U. S. production of magnesium metal.. In 1972, this
amounted to 15,662 short tons/1^ most of which was recovered from
aluminum alloys. Emissions from the magnesium segment include minor
amounts of particulates and gases emitted to the atmosphere and solid
waste to the land.
Raw Materials
Major sources of raw material to this segment include new
scrap (79 percent) and old scrap (21 percent). Most of the new scrap
comprises magnesium-aluminum alloys generated in-house in the fabrication
and machining of finished components. The old scrap, also comprised of
magnesium-aluminum alloys, is generated from scrap automobile and aircraft
parts and, therefore, contains hand sortable ferrous and nonferrous
metallic parts. Other sources of scrap include drosses and sludges.
Products
Products from the magnesium segment of the secondary nonferrous
metals industry include:
(1) Magnesium alloy ingot
(2) Magnesium alloy castings and shapes
(3) Aluminum-magnesium alloys
(4) Zinc and other alloys
(5) Cathodic protection rods.
Items (1) , (3), and (5) constitute more than 90 percent of the
products.
(1) Telephone conversation with E. Chin, Chemist, Division of Nonferrous
Metals, USBM, Washington, D. C.
-------
C-118
Process Description
The recovery of magnesium from scrap involves three manufacturing
operations: (1) scrap pretreatment, (2) smelting, and (3) casting. These
operations and the individual processes under each operation are shown in
the flowsheet entitled "Magnesium Segment of The Secondary Nonferrous
Metals Industry"
Scrap Pretreatment Operation
Magnesium scrap is hand sorted to separate the large and easily
identifiable pieces of other metals from the scrap magnesium parts as shown
in the flowsheet and discussed below.
Hand Sorting Process (1). The process consists of separating
the magnesium and magnesium-alloy parts from all the other metals present
in the scrap. The processing steps involve (1) spreading the scrap on
the floor and (2) hand picking the lightest pieces which are magnesium and
magnesium-alloys. This hand picking of light metal becomes second nature
to the person experienced in the process.
The process does not require any energy except human labor.
Fine particles left on the floor constitute the solid waste
generated by this process. It is usually insignificant as a source of
pollution. Thus, the hand sorting process does not offer any potential
for pollution.
S_melt_ing Operation
The smelting of sorted scrap magnesium and the smelting of
drosses and sludges are the two processes under this operation. However,
the same company does not necessarily do both these operations. The scrap
melting facility finds it convenient to ship its sludge (slag) to a sludge
processing facility, thus avoiding a potential solid waste disposal problem
at the scrap melting plant.
-------
C-119
Open Pot Melting Process (2). The sorted solid magnesium and
alloy scrap is transferred to a melt crucible of about 1000-lb capacity,
where the scrap is melted and the magnesium separated from the contaminants,
The process steps are: (1) heat the crucible to melt the scrap, (2) add
flux which is a mixture of calcium, sodium, and potass.ium chlorides,
(3) pour the molten metal into molds, (4) cast the ingots, and (5) remove
the slag or sludge.
Thermal energy is the main energy requirement of this process.
The wastes generated are: (1) gaseous effluents consisting of
chlorine, hydrogen chloride, smoke from oil and grease, and particles of
dust, including small amounts of magnesium oxide (MgO); and (2) solid
waste as sludge containing slag which is sent for reprocessing at a sludge
smelter. The estimated uncontrolled particulate emission factor for a pot
(2)
furnace is 4 Ib per ton of metal processed.
This process has a moderate air pollution problem arising from
the gases generated. In fact, the in-house pollution is a greater threat
to the plant personnel than it is to the public by way of ambient air
pollution. Some installations use hoods to vent the gases to ambient air.
The potential pollution from this process is significant by way
of air pollution if not controlled properly.
Sludge Smelting Process (3). This process recovers magnesium
from sludges produced in primary and secondary smelters. The process
steps are: (1) heating, (2) flux addition, (3) slag removal, and (4)
casting.
Energy required for this process is thermal energy.
Potential pollutants from this process are solid wastes and
atmospheric emissions. The solid waste--slag--contains the fluxes and
contaminants removed from the scrap. The atmospheric emissions are
composed of chlorine and hydrogen chloride gases from the melting pot,
combustion gases, and dust.
(2) USEPA, "Compilation of Air Pollution Emission Factors", Publication
AP-42, USEPA, Washington, D. C. (April, 1973).
-------
C-120
The atmospheric emissions, if uncontrolled, present an
atmospheric pollution problem, while the slags are a source of water
pollution if disposed of in an unapproved landfill.
Casting Operation
Ingot Casting Process (4). The molten magnesium is cast into
ingots in this process. The process steps are: (1) covering the melt
with a protective flux, (2) pouring the melt into casting dies, and
(3) casting the melt.
Energy requirements of this process are not significant.
Minor quantities of atmospheric emissions are generated. Thus,
the quantity of emission is too small to represent any pollution potential,
Population of Secondary Magnesium Processors
(1) American Smelting and Refining Company
Federated Metals Division
12 Pine Street
New York, New York
(2) Apex Smelting Company
Division of Amax Aluminum Company
2515 West Taylor Street
Chicago, Illinois
Telephone: (312) 332-2214
(3) Standard Magnesium
Division of Kaiser Chemicals
41st and Memorial Drive
Tulsa, Oklahoma
(4) White Metal Rolling and Stamping Corporation
84 Moultrie Street
Brooklyn, New York
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-------
C-122
PROCESS DESCRIPTION OF THE MERCURY SEQ1ENT OF
THE SECONDARY NONFERROUS METALS INDUSTRY
The U. S. production of mercury by secondary recovery processes
was 12,139 flasks in 1972, representing 62 percent of all mercury
produced in the U. S. in that year. The salient statistics on the con-
sumption and production of mercury for the preceding two years are as
follows.(2)
1971 1972
Domestic consumption--flasks 52,275 52,907
Production, primary processing 17,883 7,286
secondary processing 10,899 12,139
Imports (for consumption) 28,449 28,834
The data indicate a sharp rise in mercury production by this
segment while production from the primary industry declined sharply,
probably due to a decrease in demand caused by the stringent mercury
(3)
emission standards in December, 1971.
Emissions to the land, water, or air from secondary mercury
processing, quantitatively speaking, are not significant. However, the
extreme toxicity of the mercury vapor makes a careful study of this
industry worthwhile. Due to the relatively high vapor pressure of mercury,
ambient mercury concentrations around open vessels can be sufficiently
greater than the threshold limit value (TLV) even at ordinary pressure and
temperature. If good housekeeping in the secondary processing plants is
insured, mercury pollution will not reach significant levels. The flowsheet
on the mercury segment of the Secondary Nonferrous Metals Industry provides
a flow of the processes and potential sources of emissions from each of the
processes.
(1) Flask as used throughout this segment report refers to the 76-Ib flask.
(2) Telephone conversation with V. Anthony Canunarota, Jr., Mercury
Specialist, USBM, Washington, D. C.
(3) Federal Register, National Emissions Standards for Hazardous Air
Pollutants, Vol. 36, No. 234, pp 23,239-23,256 (December, 1971).
-------
0123
Raw Materials
Reported high volume sources of scrap for reprocessing include
the following:
(1) Salvage from instrument and electrical manufacturers,
research laboratories (dirty liquid mercury from
research organizations, educational institutions, etc.)
(2) Mercury battery scrap
(3) Industrial scrap
(4) Dental amalgam.
The most common single source mentioned is dental amalgam,
though the absolute volume of this source is relatively small. Obviously,
in this case, silver, rather than mercury, provides the primary incentive
(4)
for recovery.
Federal Effluent Standards for water considered to be in the
making may have created another source of scrap mercury. The chlor-alkali
plant liquid effluent contains about 20 ppm mercury which needs to be reduced
to less than 5 parts per billion (ppb) which is considered to be the level
of mercury allowable by the regulations. Rosenzweig ' outlines the flow
schemes of two processes for mercury recovery from wastewater. One of
them, the Osaka Soda Process, generates a resin as a solid waste containing
small amounts of recoverable mercury. The solid waste generated is not
significant (about 1000 Ib per year). Also, the amount of mercury recovered
by these processes is not significant enough to warrant further study as a
scrap recovery system.
Product
The product from the mercury segment of the secondary metals
industry is liquid mercury.
(4) ORNL Report, "Survey of the Mercury Reprocessing Industry 1968-1970",
Report No. NSF-EP-22, ORNL, Oak Ridge, Tennessee 37830 (October, 1972).
(5) Rosenzweig, Mark D., "Pairing Mercury Pollution", Chemical Engineering,
pp 70-71, February 22, 1971.
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C-124
Process Description
The recovery of mercury from scrap involves three manufacturing
operations: scrap pretreatment, refining, and bottling. These operations
and the individual processes under each operation are shown on the flowsheet
entitled "Mercury Segment of the Secondary Nonferrous Metals Industry".
Scrap Pretreatment Operation
There is no pretreatment of the scrap when vacuum distillation
is employed as the refining method. The dirty liquid mercury scrap is
fed directly to the distillation vessel. However, during transfer of the
scrap mercury from the storage to the distillation flask, a small quantity
of mercury may escape as vapor. This does not constitute any potential for
widespread pollution. Building ventilation at the plant is sufficient to
reduce the mercury levels to below the OSHA's TLV of 100 ng/m (Federal
Register, Vol. 37, No. 202, October 18, 1972).
Prefiltration Process (1). This is a pretreatment operation used
only with the oxygenation process and when the mercury scrap contains
insoluble impurities that need to be removed before oxygenation starts. In
fact, this is the only scrap pretreatment operation in the entire secondary
mercury industry. The process removes insoluble impurities by filtering
which is a single process step.
Energy, mostly electrical, is required for the filtration process.
The solid waste (dirt) generated is sent to the retorting process
for recovery of trace amounts of mercury that may be present.
The prefiltration process presents no potential serious pollution
problem providing the area is vented and gases are cleaned prior to emitting
to the atmosphere.
-------
C-125
Refining Operation
There are four different processes used for refining scrap
mercury. The process employed depends on the type of scrap. Each of the
processes (2 through 5) is shown in the flowsheet on the mercury segment
and discussed below.
Vacuum Distillation Process (2). When the vapor pressure of the
impurities is substantially lower than that of mercury, purification by
vacuum distillation which separates a high purity mercury from the impurities
is employed. The distillation unit consists of a still pot for heating the
impure mercury, a water cooled condenser, and a pure mercury receiving
vessel. The processing steps are: (1) heating the still pot by external
heat to vaporize the mercury at an absolute pressure of 0.01 torr (0.01 mm
Hg Pressure), (2) condensing the mercury in water-cooled condensers, and
(3) collecting the clean mercury in a receiver. Afterwards, the still
residue is removed for further processing.
Energy requirements for this operation are: (1) heat energy for
heating the distillation still and (2) electrical energy to operate the
vacuum pump and associated equipment.
The main source of potential pollution is the exhaust gas from
the vacuum pump. Estimated maximum mercury emissions by distillation
are 0.02 Ib per 760 Ib of mercury produced. Solid waste residue from the
still pot is normally recycled to other refining processes. No liquid
effluent is produced in this process.
The process has no serious pollution potential if good housekeeping
practices are employed and precautions are taken to control emissions.
Solution Purification Process (3). This process removes metallic
and/or organic impurities contained in the dirty liquid mercury by washing
with a dilute acid. The processing steps are (1) leaching metallic
impurities with dilute nitric acid using compressed air to mix the acid and
(6) Battelle's Columbus Laboratories report to EPA, "Topical Report on
Basis for National Emission Standards on Mercury", Battelle's Columbus
Labs, Columbus, Ohio, June 15, 1971.
-------
C-126
mercury; (2) separating the mercury layer from the aqueous nitric acid slurry
by decantation; (3) water washing to remove residual acid, and (4) filtering,
probably through a bed of activated charcoal and silica gel, to remove last
traces of water. If the mercury contains organic impurities, the scrap
mercury is treated in the same manner with organic solvents.
Electrical energy is required to operate the compressor and
associated equipment. Pumping the mercury is avoided by use of gravity flow
scheme from overhead tanks.
Potential pollutants generated by this process are atmospheric
emissions, liquid wastes, and solid wastes.
The atmospheric emissions containing mercury vapor result from
sparging of the liquid mercury during the leaching step. The spent leach
liquor is the source of liquid waste, while the solid waste consists of the
contaminated filter media.
In view of the hazardous nature of mercury, pollution problems
can result.
Oxygenation Process (4). This process, also called oxification,
removes the metallic impurities contained in dirty liquid mercury by oxidation
with sparging air. The process steps are; (1) sparging the dirty mercury
with air in a closed, agitated vessel for several hours and (2) filtration
to remove solid metal oxides. Finally, the filtered mercury is bottled which
is discussed in the bottling process.
Electrical energy is required for sparging and water scrubbing
process steps.
Sparging air which contains saturation levels of mercury at 77 F
is a potential atmospheric pollutant. However, before venting to the
atmosphere, it is generally water scrubbed and filtered through a bed of
charcoal to remove the mercury. The water is recycled many ti.nes before
discharge because mercury settles out of the water. In most cases, the
solid waste as filter cake is sent to the retorting process. Thus, the
potential pollutants from this process are atmospheric emissions, liquid
wastes, and solid wastes.
The potential for pollution from this process is not significant,
providing pollutants are treated before discharging to the environment.
-------
C-127
Retorting Process (5). This process produces pure mercury by
volatilization of the mercury contained in solid scrap. Examples of scrap
are dental amalgams, mercury battery scrap, and distillation sludges. The
process steps are: (1) external heating of solid scrap in a closed still
pot or stack of trays to volatize the mercury, (2) cooling mercury vapor in
water-cooled condensers to condense the vapors, and (3) bottling which is
discussed in Process (6).
Heat energy is required for volatilization of mercury and
electrical energy for cooling water circulation.
Potential pollutants generated by the process are atmospheric
emissions from the retort, liquid wastes from the condenser, and cleaning
of the atmospheric emissions and solid wastes as the retort residue, each
containing mercury. The degree of pollution can be reduced by scrubbing of
the process gases prior to emission to the atmosphere, packaging of the
retort residue and disposing of it in a hazardous landfill, and treating the
liquid wastes prior to disposal.
Because of the hazardous nature of mercury, this process can be.a
source of serious pollution problems.
Bottling Operation
Bottling Process (6). Bottling of the purified mercury is done to
enable marketing of the product in 76-lb flasks.
The steps are (1) pumping or manual pouring of the mercury into
the 76-lb bottles and (2) sealing the bottling.
Electrical energy is used for pumping the mercury to the bottles.
The only waste emission is mercury vapor (at 77 F), produced when
pumping or pouring mercury into the bottle. This is not a significant source
of air pollution but can cause high levels of mercury vapor inplant. Building
ventilation air is used to reduce the mercury levels to below the TLV.
The bottling process does not offer any potential for serious air
pollution.
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C-128
Population of Secondary Mercury Processors
(I) Florida Smelting Company
2640 Capitola Street
P. Box 3404
Jacksonville, Florida
Telephone: (904) 353-9317
(2) Kahl Scientific Instrument Corporation
737 West Main Street
El Cajon, California 92022
Telephone: (714) 444-5944
(3) Metallurgical Products Company
35th and Moore Streets
Philadelphia, Pennsylvania 19148
Telephone: (215) 394-8300
(4) Wood-Ridge Chemical Corporation
Park Place East
Wood-Ridge, New Jersey 07075
Telephone: (201) 939-4600
(5) Eastern Smelting and Refining Corporation
35 Bubier Street
Lynn, Massachusetts 01901
(6) Martin Metals, Inc.
1321 Wilson Street
Los Angeles, California 90021
(7) Mallory (P.R.) and Company, Inc.
3029 East Washington Street
Indianapolis, Indiana 46206
(8) Bethlehem Apparatus, Inc.
890 Front Street
Hellerton, Pennsylvania 18055
(9) Dresher Metal Trading, Inc.
Box 44
Dresher, Pennsylvania 19025
(10) D. F. Goldsmith Chemical and Metal Corporation
109 Pither Avenue
Evanston, Illinois 60202
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C-129
(11) Williams Gold Refining, Inc.
2978 Main Street
Buffalo, New York 14214
(12) Merck and Company
Metal Salts Division
Hawthorne, New Jersey
(13) Iritox Chemical Company
284 Hamilton Avenue
Brooklyn, New York 11231
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C-131
PROCESS DESCRIPTION OF THE NICKEL SEGMENT
OF THE SECONDARY NONFERROUS METALS INDUSTRY
During 1971, this segment recovered 29,657 short tons of nickel,
mostly as alloys, from old and new scrap. This recovery amounted to about
30 percent of total U.- S. nickel consumption. It is estimated* that only
about 40 percent of the available scrap is recycled. The remaining
60 percent, such as used nickel-cadmium batteries and spent nickel-base
catalysts, are disposed of in landfills. Emissions to the environment
from this segment are atmospheric emissions and solid wastes.
Raw Materials
Raw materials include old scrap (74 percent) and new scrap
(26 percent) both comprising of nickel-, copper-, and aluminum-base alloys.
The scrap originates as used burners (inconel), airplane parts, sheet
scrap, electrical scrap, and so on. An exact percent breakdown of the
contribution of these sources is not available.
Products
Products from the nickel segment are slag and the following
alloys:
(1) Stainless steels (18/8 and other grades)
(2) Nickel-base alloys (cupronickel, nickel silver, etc.)
(3) Base alloys (low alloy steels)
(4) Nickel metal (quantitatively not significant).
Process Description
The recovery of nickel as nickel alloys from scrap involves
three manufacturing operations: (1) scrap pretreatment, (2) smelting,
(1) Battelle's NASMI Report, "A Study to Identify Increased Solid Waste
Utilization", Battelle's Columbus Laboratories, Columbus, Ohio 43201,
(June, 1972).
-------
C-132
and (3) refining/casting. These operations and the individual processes
under each operation are shown in the flowsheet entitled "Nickel Segment
of The Secondary Nonferrous Metals Industry".
Scrap Pretreatment Operation
Hand Sorting Process (I). This process is done usually at the
scrap merchant's facilities rather than at the scrap smelting facilities.
The process segregates the nickel bearing alloys and metals
from the nickel-free components in the raw scrap.
The process steps are: (a) spread the scrap on a platform and
(b) separate the nickel scrap from the nonmetallics and nonnickel components.
Manual labor is the only energy requirement for the process.
Wastes produced are limited to a small quantity of solid wastes
which are composed of dirt and nonnickel scrap.
The pollution potential of the waste is insignificant.
Smelting Operation
In the smelting operation, partial purification of the nickel
scrap is achieved or the nickel scrap is melted and mixed with selected
alloying agents as outlined in the segment flowsheet by Processes 2 and 3.
Electric Arc Process (2). This process produces a partially
purified product which is purified further in the refining/casting
operation or nickel alloys which are cast into alloy ingots.
The process steps are: (a) charging the scrap to the electric
arc furnace, (b) adding a reductant (lime), (c) melting the charge,
(d) pouring into molds or transferring the molten metal to a reactor for
refining, and (e) removing the slag.
Electric energy is required in substantial quantities for this
process to operate the furnace. Additional energy is required to operate
the auxiliary equipment.
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C-133
Wastes generated are: (1) atmospheric emissions consisting
of large quantities of dust particles and limited quantities of gases
and (2) solid wastes consisting of furnace slag.
The off gases are invariably treated 'in a baghouse which removes
approximately 99 percent of the dust particles. Hence, the gases are clean
when vented and do not' constitute any serious air pollution problem.
However, the collected dust (about 4 tons/day at a medium size facility)
is sent to a landfill and may be considered a potential source of water
pollution by leaching to surface and ground waters. The metal value of
this dust is unknown and the industry would like to investigate possibilities
of recovery of any metals in the dust.*
The slag may or may not be a waste as, in many cases, it is
ground at another facility for use in sandblasting or road surfacing
operations.*
Rotary Reverberatory Furnace Smelting Process (3). This process
is the same as Process (2) except a reverberatory furnace is used in place
of an electric arc furnace. The process steps are: (a) charging the scrap
to the furnace, (b) adding a reductant (lime), (c) melting the charge,
(d) pouring the melt in the molds or transferring the melt to a reactor
for refining, and (e) removing the slag.
Energy required for this process is from the fuel to operate
the furnace and other forms of energy to operate the auxiliary equipment.
Potential environmental pollutants produced by this process are
atmospheric emissions and solid wastes. The atmospheric emissions are
composed of dust particles and gases. These are, in most cases, treated
in baghouses which collect approximately 99 percent of the particulate
matter. The solid waste is generated as slag and, in most cases, is
ground at another facility for use in sandblasting or road surfacing
operations.
Thus, the smelting process is a potential source of pollution
problems. These problems may result from disposal of the baghouse dusts
* Conversation with Leonard Arness, ARMCO Steel Advanced Metals Division,
P. 0. Box 1697, Baltimore, Maryland 21203.
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C-134
via landfill which could result in contamination of the water system and
possibly contamination of the atmosphere with gases and particulate matter
from pollution abatement equipment. However, atmospheric emissions do
not probably constitute a serious pollution hazard.
Reactor Finishing (4). This process, very similar to a
foundry operation, purifies the metal further and adjusts the composition
to the required values.
The process steps are: (a) charging the molten metal to the
furnace; (b) adding cold metals such as base scrap and pig nickel;
(c) adding lime, silica, and trim (manganese, columbium, titanium, etc.,
in trace quantities as required by alloy composition); (d) melting the
charge; (e) pouring into molds, and (f) removing the slag.
Large amounts of heat energy are required by the process.
Potential pollutants generated by this process are atmospheric
emissions containing gases and particulate matter and solid wastes in the
form of slag. The atmospheric emissions are treated via a baghouse
which removes approximately 99 percent of the particles. The slag is
sold as a product for use as a sandblasting material or in road surfacing
operations.
Thus, the reactor finishing process has a low potential for the
production of serious pollution problems.
Casting Operation
Ingot Casting (5). In this process the molten alloy from the
reactor or electric furnace is cast into required shapes.
The process steps are: (a) pouring into molds and (b) removing
the ingots from the mold after they are cast by air cooling.
Energy requirements of the process are minimal
-------
C-135
Wastes produced are minor amounts of metallic vapor which stays
inplant.
The potential pollution of the wastes is insignificant.
Population of Secondary Nickel Processors
(1) Alloy Metal Products, Inc.
626 Schmidt Road
Davenport, Iowa
Telephone: (319) 324-3511
(2) American Nickel Alloy Manufacturing Company
30 Vesey Street
New York, New York 10007
(3) ARMCO Steel Corporation
Advanced Metals Division
P. 0. Box 1697
Baltimore, Maryland 21203
(4) Belmont Smelting Company
330 Belmont Avenue
Brooklyn, New York 11207
(5) Frenkel Company
19300 Filer Avenue
Detroit, Michigan
Telephone: 306-5300
(6) Mercer Alloy Corporation
1 Alloy Road
Greenville, Pennsylvania 16123
(7) Metal Bank of America, Inc.
6801 State Road
Philadelphia, Pennsylvania 19135
Telephone: (215) 332-6600
(8) Paragon Smelting Corporation
36-08 Review Avenue
Long Island City, New York 11101
Telephone: (212) 729-3641
(9) Riverside Alloy Metal
Division of H. K. Porter Company, Inc.
309, Porter Building
Pittsburgh, Pennsylvania 15219
Telephone: (412) 391-1800
(10) I. Schumann Company
Division of Ogden Metals Company
22500 Alexander Road
Cleveland, Ohio
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C-136
(11) Utica Alloys, Incorporated
Box 53
Utica, New York 13501
(12) Wai Met Alloys Company
7322 Oakman Boulevard
Dearborn, Michigan
Telephone: (313) 581-7200
(13) Whitaker Metals
Alloy Division
P. 0. Box 607
Greenville, Pennsylvania 16125
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SCRAP PRETREATMENT
SMELTING
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INDUSTRY
D 79986
-------
C-138
PROCESS DESCRIPTION OF THE PRECIOUS METALS SEGMENT
OF THE SECONDARY NONFERROUS METALS INDUSTRY
This segment includes the secondary recovery methods for gold,
silver, and platinum group of metals. These are grouped together because
they derive from the same scrap and the same general recovery operations
are used to obtain the individual metals from the scrap.
Exact statistics on scrap volume are not available. However,
estimates are that about 10,000 tons of scrap are processed per year,
excluding low grade scrap which is disposed of in landfills at present.
These scrap estimates are corroborated by the secondary platinum and silver
production figures, the silver consumption of the electronic industry being
about 28 percent of the total U. S. silver consumption. Production
statistics of this segment from new and old scrap are as follows:
1971
Production of Precious Metals
Secondary
Gold
Silver
Platinum
Troy
2.2
47 x
103,
Ounces*
x IO6
io6
429
Tons
75.5
1597
3.55
Primary
Troy Ounces
1.5 x IO6
69 x IO6
10,198
Tons
51.2
2355
0.35
Percent**
1477.
68%
1014%
* One troy ounce is equal to 1.1 regular (avdp.) ounce.
** Secondary as a percent of the primary production.
Raw Materials
Electronic components such as gold-plated contacts and printed
circuit boards from military and civilian scrap equipment are the chief
source of scrap for this segment. The second important source is scrap
from the dental industry. Scrap jewelry usually goes to special smelters
as these do not require complicated processing. Thus, raw materials to
this segment include:
(1) Electronic scrap consisting of relay contacts,
switch contacts, wires, solders, etc.
(2) Dental analgams, inlays, dentures, and crowns
(3) New scrap generated in manufacturing.
-------
C-139
Products
Products from this segment include:
(1) Refined gold metal
(2) Refined silver metal
(3) Refined platinum metal
(4) Refined palladium and trace quantities of iridium
and other metals.
Process Description
The recovery of precious metals from scrap involves three
manufacturing operations: (1) scrap pretreatment, (2) smelting, and
(3) refining/casting. These operations and the individual processes under
each operation are shown in the flowsheet entitled "Precious Metals Segment
of The Secondary Nonferrous Metals Industry".
Scrap Pretreatment Operation
Although a variety of processes are possible in scrap
pretreatment, only two processes are notably important for detailed
consideration.
Hand Sorting and Crushing Process (1). Bulk precious metals
scrap consisting of identifiable aluminum contaminants (aluminum chasis)
is hand sorted to separate the aluminum from the scrap. The aluminum-free
scrap is then crushed in a hammer mill.
The process steps are: (a) spread bulk scrap on floor,
(b) pick out aluminum parts, and (c) shred aluminum-free scrap in a
hammer mill shredder.
The process requires electrical energy for crushing.
Wastes generated consist of minor in-house dust emissions during
charging and discharging of the shredder.
The potential for pollution of wastes in this process is
insignificant.
-------
C-140
Incineration Process (2). The crushed scrap is incinerated
to burn off plastics and organic liquids and prepare a smelter feed.
The processing steps are: (a) charge to incinerator, (b) burn-
off combustible constituents, and (c) discharge smelter feed.
The process requires heat energy.
Wastes generated are: (1) atmospheric emissions consisting of
organic vapors and dust particles and (2) liquid waste if wet scrubbing
is used to control dust particles in the atmospheric emissions.
Untreated wastes have considerable ambient air pollution
potential. However, the atmospheric emissions are treated in an
afterburner to complete combustion of organic matter. Thus, the effluents
from the afterburner contain particles of dust and metal. Usually a wet
scrubber or baghouse is used to collect these particles. The amount of
dust collected by either of these control devices is not sufficient to
constitute serious solid waste problems. Similarly, any liquid waste
generated is insignificant.
Therefore, the wastes from this process have no serious
pollution potential.
Smelting Operation
Blast Furnace Smelting Process C3). This process purifies the
pretreated scrap to produce black copper.
The process steps are: (a) charging the segregated scrap with
coke and flux, (b) melting the charge, (c) slagging the melt, (d) dis-
charging black copper, and (e) removing the slag.
Heat energy is the main energy requirement of the process.
Copious amounts of atmospheric emissions and moderate quantities
of solid waste—hard slag--are generated in the process. The atmospheric
emissions are treated in a baghouse. The collected dust is landfilled.
The hard slag is crushed and used in sand blasting operations.
Therefore, the wastes generated in this process do not have
significant pollution potential.
-------
C-141
Converter Purification (4). The black copper is further
purified by oxidizing the contaminating metals with air blown through
the heated copper. The end product is bullion (copper rich in precious
metals).
The process steps are: (a) charging the converter, (b) blowing
the melt, (c) removing the slag, (d) pouring the melt into molds, and
(e) casting the ingots.
Heat energy is the main energy requirement.
Wastes generated are: (1) minor amounts of atmospheric emissions
and (2) slag metal oxides. The slag metal oxides are recycled to the
blast furnace.
Therefore, the process has no significant pollution potential
if the atmospheric emissions are controlled.
Refining/Casting Operation
Electrolytic Refining Process (5). The bullion from the
converter (as the anode) is electrolytically separated into pure copper
(cathode) and precious metal slimes.
The process steps are: (a) charging the electrolyte (copper
sulfate - CuSO,), (b) electrolysis, and (c) slime recovery.
Electrical energy is required in this process.
Waste products are limited to minor amounts of gaseous hydrogen
and arsine. Quantitatively, these wastes do not represent significant
potential for pollution. Arsine is very much below TLV levels.
Chemical Refining Process (6). The precious metals slime
from the electrolytic process is refined to isolate each of the precious
metals by complex chemical processes.
The process steps are: (a) treating the slime with aqua regia
to dissolve the precious metals; (b) precipitate the gold, silver, and
platinum with suitable chemical solutions; and (c) melt or ignite to collect
gold and silver as grains and platinum and palladium as sponge.
The process requires electrical and thermal energy in moderate
quantities.
-------
C-142
Wastes include waste liquor discharged to waterways and
atmospheric emissions generated during melting and ignition.
The process has a low potential for the production of
atmospheric emission problems if emissions are controlled. Discharge
of the spent liquor to the waterways could result in pollution problems,
Population of Secondary Precious Metals Industries
(1) Joseph Behr and Sons, Inc.
1100 Seminary Street
Rockford, Illinois
Telephone: (815) 962-7721
(2) Eastern Smelting and Refining Corporation
105 West Brookline Street
Boston, Massachusetts 02118
(3) Handy and Harman
850 Third Avenue
New York, New York 10022
Telephone: (212) 752-3400
(Refining of precious metal scrap is carried out in
Fairfield, Connecticut and Los Angeles, California)
(4) Hudsar, Inc.
567 Wilson Avenue
Newark, New Jersey 07105
Telephone: (201) 642-7334
(5) Metallurgical Products Company
35th and Moone Streets
Philadelphia, Pennsylvania 48300
Telephone: (215) 394-8300
(6) Pease and Curren, Inc.
780 Aliens Avenue
Providence, Rhode Island 02905
Telephone: (401) 461-6340
(7) Phelps Dodge Refining Corporation
300 Park Avenue
New York, New York
Telephone: (212) 751-3200
(8) United States Metals Refining Company
1270 Avenue of the Americas
New York, New York 10020
Telephone: (212) 757-9700
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METALS INDUSTRY
0 79986
-------
C-144
PROCESS DESCRIPTION OF SELENIUM SEGMENT
OF SECONDARY NONFERROUS METALS INDUSTRY
Tonnage-wise, the selenium segment constitutes one of the minor
segments of the secondary nonferrous metals industry. Based on 1971 data,
30,000 Ibs or about 3 percent of the total U. S. consumption was recovered
from scrap. Wastes from this segment are atmospheric emissions, liquid
wastes, and solid wastes.
Raw Materials
Sources of raw materials for this segment, including both new and
old scrap, are:
(1) Selenium rectifiers (burned out and factory rejects)
(2) Spent catalysts
(3) Used xerographic plates.
Products
The product from this segment is metallic selenium in the form of
shot, refined powder, and selenium ingots.
Process Description
The recovery of selenium from selenium scrap involves three manu-
facturing operations: scrap pretreatment, smelting/refining, and casting
(product formation). These operations and the individual processes under
each operation are shown on the flowsheet entitled "Selenium Segment of the
Secondary Nonferrous Metals Industry".
Scrap Pretreatment
Selenium is separated from the majority of the other scrap compo-
nents in the scrap pretreatment operation.
-------
C-145
Mechanical Process (1). The selenium is separated from the other
scrap components by hammer-mi11 ing, shot blasting, and similar methods. The
recovered selenium is further processed or sold as a selenium metal.
Energy demand is that needed to drive the equipment.
The process produces atmospheric emissions and. solid wastes. The
atmospheric emissions contain particulates of selenium metal, compounds,
alloys, and oxide, whereas the solid wastes are composed of metallic and
nonmetallic scrap.
Smelt ing/Re fin ing Operation
In the smelting/refining operation, the pretreated scrap is puri-
fied to produce selenium metal for subsequent processing. The processes by
which the purification is achieved are Numbers 2 through 4 on the flowsheet.
Retort Smelting Process (2). In retort smelting, partial purifi-
cation of the pretreated scrap is achieved and the scrap is densified. The
process steps are: (1) charging the retort, (2) melting the scrap, (3) sep-
arating the selenium from the impurities by distillation, and (4) discharging
the residue from retort.
The energy required is that needed to heat the retort.
Potential environmental pollutants are atmospheric emissions, solid
wastes, and liquid wastes. The atmospheric emissions are composed of gases
and particulate matter containing selenium. The solid wastes contain the
impurities from the scrap selenium. These wastes may go to landfill. The
liquid waste is cooling water which may be recycled in most cases.
Thus, retort smelting has the potential for producing atmospheric
pollution problems as well as water pollution problems from leaching in the
landfill.
Hydrometallurgical Refining (3). Hydrometallurgical refining also
achieves a partial purification of the scrap selenium. The process steps
are: (1) dissolve the scrap selenium or the selenium from Process 2 in a
-------
C-146
suitable solvent such as aqueous sodium sulfite, (2) remove insoluble impur-
ities by filtration, and (3) precipitate the selenium for further purifica-
tion.
The energy required is that needed to heat the solutions and oper-
ate the auxilliary equipment.
Potential environmental pollutants are atmospheric emissions if
gases are used to precipitate the selenium, liquid wastes, and solid wastes.
The process has the potential for the generation of pollution problems.
Distillation Process (4). This process yields high-purity selenium.
The process steps are: (1) charge the distillation unit, (2) melt and dis-
till the selenium, (3) condense the selenium vapors, (4) transfer molten
selenium to the product formation operation, and (5) remove residue.from
the still.
The energy required is that needed to operate the distillation unit.
Potential pollutants are atmospheric emissions composed of distilla-
tion wastes and particulates of selenium, solid wastes, and liquid wastes.
This process also has the potential for the production of pollution problems.
Product Formation Operation
In product formation, the molten selenium is converted to the de-
sired shape. The processes used to achieve this are Processes 5 and 6.
Quenching Process (5). The quenching process produces selenium
shot and selenium powder. The process steps for the production of selenium
shot are: (1) quench the selenium melt in a quenching liquid, (2) separate
the shot from the cooling liquid, and (3) dry the shot. Powder is produced
by quenching the selenium vapors from the distillation unit.
Energy required is that needed to cool the quenching medium and
operate the auxilliary equipment.
-------
C-147
Potential pollutants are liquid wastes such as cooling water which
is recycled in most cases. The process has a low potential for the produc-
tion of pollution problems.
Casting Process (6). By this process, the molten selenium is
cast into ingots or other shapes. The process steps are: (1) pour the
molten selenium into the molds and (2) solidify the melt.
Energy is needed to operate the equipment.
Essentially no pollutants are emitted. Thus, the process has no
potential for the production of pollution problems.
Population of Secondary Selenium Processors
(1) Kawecki-Berylco Industries
Box 1462
Tuckertown Road
Reading, Pennsylvania 19603
(2) American Smelting and Refining Company
3422 South 700 West
Salt Lake City, Utah 84119
(3) U. S. Metals Refining Company
Division of American Metals Climax, Inc,
300 Middlesex Avenue
Carteret, New Jersey
(4) Eastern Metal Converters, Inc.
52 Wall Street
New York, New York
Telephone: 4-5778
(5) Kawecki-Berylco Industries, Inc.
220 E. 42nd Street
New York, New York
(6) Metallurgical Products Company
35th and Moore Streets
Philadelphia, Pennsylvania
Telephone: 344-8300
-------
C-148
(7) Max Zuckerman and Sons
Music Fair Road
Owings Mills, Maryland 21117
Telephone: (301) 484-0400
(8) Phelps Dodge Refining Corporation
300 Park Avenue
New York, New York
(9) Belmont Smelting and Refining Works
320 Belmont Avenue
Brooklyn, New York 11207
Telephone: (212) 624-4004
(10) Alloy Chem, Inc.
641 Lexington Avenue
New York, New York 10022
Telephone: (212) 421-6300
-------
8
SCRAP PRETREATMENT
SMELT I'.JC/ REFINING
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-------
C-L50
PROCESS DESCRIPTION OF THE TIN SEGMENT OF
THE SECONDARY NONFERROUS METALS INDUSTRY
The importance of the tin segment of the secondary nonferrous
metals industry is highlighted by the fact that virtually all U. S.
primary tin requirements (69,029 tons in 1972) are imported and that the
secondary production constitutes about one-third of total U. S. production.
In 1972, this amounted to 20,180 long tons. The forecast demand for tin
for the year 2000 is about 120,000 long tons.
Additional salient tin recovery statistics for the U. S.^ ' are
provided below.
1967 1971 1972
Secondary tin recovered (long tons) 21,000 20,096 20,180
U. S. tin consumption (long tons) 82,000 69,950 69,029
Percent secondary tin recovery 25.6 28.7 29.2
Percent as primary tin 16 10 10
Percent as alloy, etc.
Minor sources of air pollution are the dross smelting and gas
fired refining processes. The water pollution potential from the chemical
detinning operation is the major pollution problem of the tin scrap
recovery segment.
Raw Materials
Major raw material sources for scrap recovery are the trimmings
and rejects from the can companies and rejected plating coils from the
steel industry. Although the used food cans and containers constitute
a vast potential source of raw material, their present contribution to the
recoverable scrap is only one percent. Even this one percent is collected
by the ecology minded groups like the Isaac Walton group, etc. Other than
these groups, there is no organized method of used can collection for
scrap recovery. Almost 99 percent of the used cans find their way to
municipal incinerators.
(1) U. S. Bureau of Mines, Washington, D. C., Telephone Conversation
with Keith Harris.
-------
C-151
The recovery of scrap from used cans is not expected to exceed
the current level because of the aluminum and plastic used in production of
cans. The high cost of segregating the 'tin and iron metal portion from
the garbage and the difficulties in processing the metal cans to recover
the tin in the presence of aluminum are negative incentives to increased
usage of used cans in scrap recovery. Thus, the raw materials are mostly
new scrap consisting of:
(1) Tin drosses and sludges
(2) Solder drosses and sludges
(3) Can rejects from can companies
(4) Rejected plating cells
(5) Bronze used parts and rejects
(6) Type metal scrap.
Products
Products from the tin segment of the secondary nonferrous
metals industry include:
(1) Pig tin
(2) Solder and type metal (tin-lead alloy with
varying amounts of antimony)
(3) Tin oxide
(4) Fire-refined tin
(5) Sodium stannate
(6) Stannous sulfate and other tin chemicals
(7) Babbit metal.
Process Description
Three manufacturing operations are employed to recover tin from
scrap: (1) scrap pretreatment, (2) detinning/smelting, and (3) refining/
casting. These operations and the associated processes are shown in the
process flowsheet for the tin segment of the secondary nonferrous metals
industry.
-------
C-152
Scrap Pretreatment Operation
The pretreatment process varies according to the type of scrap.
The individual pretreatment processes are Numbers 1 and 2 on the segment
flowsheet.
Dealuminization Process (1). This process is conducted only
if the scrap tin cans are suspected to contain substantial quantities of
aluminum ends. About 90 percent of the time dealuminization is not done.
This process removes aluminum as sodium aluminate in solution.
The steps are: (a) leach the scrap in hot sodium hydroxide, (b) remove
the sodium aluminate solution, (d) pump it to Process No. (7) of the
refining operation for recovery of soluble tin values, and (d) recover
dealuminized tin scrap for Process No. (3).
Heat energy for alkali solution and electrical energy for
pumping are required.
The process produces no wastes; hence, there is no potential
pollution from this process.
Batch Mixing Process (2). This mechanical operation mixes
the drosses with limestone and coke to prepare a feed suitable for smelting.
Mixing is the only process step involved.
Electrical energy for the rotary drum mixer is required.
Dust emissions are produced. However, these are collected by
baghouses and recycled. The process, therefore, has no pollution potential.
Detinning-Smelting Operation
By the detinning-smelting operation, the tin values in scrap
are separated from metallic and nonmetallic impurities or contaminants.
Two types of operation--hydrometallurgical and pyrometallurgical--are used.
The individual processes are numbered 3 through 5 in the flowsheet.
-------
C-153
Chemical Detinnlng Process (3). The process extracts the tin
value in the scrap as sodium stannate solution and also generates detinned
steel scrap for use in secondary ferrous' metallurgy.
The process steps are: (a) addition of hot alkali (NaOH) and
sodium nitrite or nitrate (NaNCL or NaNO^) solution to the scrap, (b)
draining and pumping the solution to the refining/casting operation after
the reaction is complete, and (c) washing the detinned scrap with water
sprays (as many as four) to obtain clean scrap for the steel industry.
Three of the sprays are pumped to the crude sodium stannate solution tank
and the fourth spray is used for recycle.
Heat energy is required to heat the caustic solution and
electrical energy for pumping stannate solution and spray water.
No significant quantities of wastes are generated in the process
and hence there are no serious pollution problems.
Dross Smelting Process (4). This process partially purifies
the drosses and produces "crude furnace metal".
The process steps are: (a) charging the furnace, (b) melting
the charge, (c) tapping the "crude furnace metal", and (d) tapping matte
and slag.
(2)
Heat energy is required in smelting. It is reported that
90 gallons of fuel oil per ton of charge are used in the process.
The matte produced is shipped to the copper smelter. The slag
is discarded if low in metal values. Cooling water is recycled in a
closed loop operation. Hence, the only wastes are minor atmospheric wastes
and major amounts of slag. Almost 99.9 percent of dust in the furnace
gases is collected in an electrical precipitator and leached in Process (5).
The process has reasonable potential for solid waste pollution.
Dust Leaching and Filtrajion Process (5_). The tin and chlorine
values in the Cottrel dust collected in Process (4) are separated from
the dust by sulfuric acid leaching. The process steps are: (a) leaching
(2) Earl R. Marble, Jr., "Redesigning a Secondary Smelting Plant", Journal
of Metals, pp 218-222, March, 1951.
-------
C-154
the Cottrel dust with dilute sulfuric acid to remove zinc and chlorine,
(b) filtering to remove acid and dissolved zinc and chlorine, (c) drying
the leached dust, and (d) conveying the drred leached dust to Process (2).
Energy required for this process is electrical energy and that
derived from fuel oil.
Potential environmental pollutants generated by this process
are atmospheric emissions from handling of the dust and drying of the
leached dust, liquid.wastes from the leaching and filtering steps, and
solid wastes collected via a baghouse from the atmospheric emissions.
Thus, the process has a potential for the production of
pollution problems if the pollutants are not collected and disposed of
in an acceptable manner.
Refining/Casting Operation
Via this operation, the tin is recovered as sodium stannate of
commerce, as stannic oxide, as pure metallic tin, and as tin alloys. The
individual processes to produce these products are 6 through 13 as noted
in the flowsheet.
Settling and Leaf Filtration Process (6). This process produces
a purified stannate solution from which tin can be recovered by a number
of processes. The impurities — silver, mercury, copper, cadmium, some
iron, cobalt, and nickel--are precipitated as metal sulfides.
The process steps are: (a) addition of sodium sulfide with
agitation, (b) settling, (c) decantation, and (d) filtration.
Electrical energy is required for agitation and filtration steps,
The process has marginal potential for solid waste disposal
problems. These solid wastes are generated as metal sulfides.
Evapocentrifugation (7). This process produces a sodium
stannate of commerce (Na^SnO-) product.
The process steps are: (a) heating the solution to concentrate
the' sodium stannate solution, (b) crystallization of sodium stannate, and
(c) recovery of the stannate by centrifugation.
-------
C-155
Thermal energy for evaporation and electrical energy for
centrifugation are required.
The wastes produced are atmospheric emissions consisting of
water vapor and liquid wastes.
The process has no substantial pollution potential.
Electrolytic Refining Process (8). This process produces
cathodic pure tin metal from the purified sodium stannate solution. The
process steps are: (a) passing the alkaline electrolyte (sodium stannate
solution) through a cascade of cells at about 190 F, a characteristic
condition with an initial concentration of 110-120 g/1 of tin; (b) removal
of cathode as tin builds up; and (c) stripping the tin from the cathode.
Electrical energy is required for electrolysis and to operate
auxiliary equipment.
Spent electrolyte, an alkaline solution, is generated as a
liquid waste. This waste has moderate water pollution potential.
Acidification and Filtration Process (9). The process produces
"tin hydrate" which is subsequently processed to tin and stannic oxide.
The process steps are: (a) acid neutralization with sulfuric
acid to form "tin hydrate" and (b) filtration to separate the hydrate as
filter cake. The filtrate is recycled to Process (6).
Electrical energy is used for stirring and filtration.
No wastes per se are generated in the process and hence the
process has no pollution potential.
Fire-Refining (10). This process produces purified tin from
cathodic tin. Natural gas is the heat source. The process steps are:
(a) charging the furnace, (b) melting of the charge, (c) removing the
impurities as slag and dross, (d) pouring of the molten metal, and
(e) casting of the metallic tin.
Energy required for this process is that derived from natural gas.
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C-156
Potential pollutants are atmospheric emissions--gases and
metallic fume--and solid wastes. The solid wastes are recycled for
metals recovery. Thus, the process is not a source of serious pollution
problems.
Smelting Process (11). This is an alternate route to producing
pure tin when electrolysis is not feasible. The process converts the tin
hydrate to tin metal by reducing the stannic oxide (SnCL) with a reducing
agent.
The process steps are: (a) heating the hydrate, (b) adding
the reducing agent, (c) reducing the tin hydrate, (d) melting the tin,
(e) skimming the dross, (f) pouring the molten metal, and (g) casting
the metal.
Heat energy derived from the fuel is the main energy requirement
of the process.
Potential pollutants are solid wastes, liquid wastes, and
atmospheric emissions. The solid waste produced as dross is recycled.
The water used to cool castings is recycled although eventually some of
it is rejected to the waterways. Atmospheric emissions are collected via
baghouses or wet scrubbers.
The pollution potential of the process does not appear to be
significant.
Calcining Process (12). This process converts tin hydrate to
anhydrous stannic oxide (SnCL). The process steps consist of: (a)
charging the calciner, (b) calcining the tin hydrate, and (c) removing
and packaging the stannic oxide.
Energy required is thermal energy.
The primary pollutant is atmospheric emissions consisting of
water vapor, dusts, and fume. Solid wastes generated are those collected
in the baghouse.
Thus, this process has a potential for the production of
pollution problems.
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C-157
Kettle Refining Process (13). This process purifies the
"crude furnace metal". The process steps are: (a) dry dressing to remove
the impurities as slag and matte, (b) decopperizing using sulfur, (c)
removing antimony using aluminum, and (d) casting into required shapes.
The process uses large amounts of heat energy as derived from
fuel oil.
The waste products generated are atmospheric emissions and
solid wastes. The solid wastes are slag and matte from the purification
of the crude furnace metal. Atmospheric emissions consist of gases from
combustion of the fuel and fume and dust entrained in the gases.
These wastes constitute reasonable potential for pollution if
not collected and disposed of by an approved method.
Population of Secondary Tin Processors
(1) Colonial Metals Company
Columbia, Pennsylvania
Telephone: (717) 684-2311
(2) K. Hettlemen & Sons
Division of Minerals & Chemicals
Phillip Corporation
9th Street & Patapsco Avenue
Baltimore, Maryland 21225
Telephone: (301) 355-0770
(3) Holtzman Metal Company
5223 McKissock Street
St. Louis, Missouri 63147
Telephone: (314) 244-3820
(4) Industrial Smelting Company
19430 Mt. Elliot at Marx Street
Detroit, Michigan
Telephone: (313) 892-5300
(5) Inland Metals & Refining Company
651 East 119th Street
Chicago, Illinois 60628
Telephone: (312) 928-6767
(6) M & T Chemicals
Rahway, New Jersey
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C-158
(7) North American Smelting Company
Marine Terminal P. 0. Box 1952
Wilmington, Delaware
Telephone (302) 654-9901
(8) United States Metal Products Company
P. 0. Box 1067
Erie, Pennsylvania 16512
Telephone: 838-2051
(9) Vulcan Materials Company
Metallics Division
Edison, New Jersey
Telephone: (201) 225-3838
-------
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-------
C-160
PROCESS DESCRIPTION OF THE TITANIUM SEGMENT OF THE
SECONDARY NONFERROUS METALS INDUSTRY
The titanium segment of the secondary nonferrous metals industry
constitutes one of the minor segments. Annual recovery of titanium is
approximately 8000 tons. Because of the nature of the operations, this
segment has a low potential for the production of serious atmospheric
emission problems. However, problems resulting from water pollution could
be significant.
Raw Materials
Raw materials to this segment include the following:
(a) Bulk scrap (trim sheets, plate sheets, cuttings, etc.)
(b) Noncarbide machine turnings and borings
(c) Carbide-containing machine turnings and borings.
This scrap is generated by the use of carbide
tools in machining.
Products
Products include titanium alloy ingots and electrodes.
Population of Companies
The following companies are known to be involved in titanium
scrap processing:
(1) RMI Company
Niles, Ohio
Telephone (216) 652-9951
(2) Titanium Metals Corporation of America
West Caldwell, New Jersey
The Air Force Materials Laboratory (AFML) of The Wright-Patterson
AFB is also pursuing recovery of the titanium values in scrap. Mr. Lee
Kannard (Telephone 513-255-2413) is working to recovery (by contracts to
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C-161
processors) titanium from low-grade scrap generated during machining of
parts for aircraft.
Process Description
The recovery of titanium alloys from scrap titanium involves
three operations: (1) scrap pretreatment, (2) smelting, and (3) casting.
These are shown in the flowsheet entitled "Titanium Segment of the
Secondary Nonferrous Metals Industry".
Scrap Pretreatment Operation
Two processes are used in this operation: vapor degreasing and
acid pickling. Normally, if the scrap is not contaminated by oxides,
acid pickling is not necessary and degreasing will suffice to produce a
clean scrap.
Vapor Degreasing (1). This process removes grease and cutting
oils from machine turnings and borings.
The process steps are: (1) vaporizing a solvent such as tri-
chloroethylene, (2) mixing the vapors with the scrap, (3) condensing the
oil-bearing vapor, (4) filtering the condensed solvent, and (5) removing
the scrap for subsequent processing. As the solvent goes through this
cycle, the oil dissolves in the solvent and gradually lowers the boiling
point of the solvent mixture. Eventually, the oil-solvent mixture is discarded
due to loss of deoiling ability of the solvent or the solvent is regenerated.
Heat energy is required by the process for vaporizing the oil
and electrical energy for water circulation through condenser.
Wastes generated are the oil-solvent mixture, minor amounts of
solvent vapor and insignificant quantities of solid dust particles.
The oil-solvent mixture has a considerable water pollution
potential. Atmospheric emissions and solid wastes generated are
negligible and thus, present no serious pollution problems.
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C-162
Acid Pickling Process (2). This process is done only when the
scrap is known to contain oxide-scale formed during machining and storage.
The process follows vapor degreasing and consists of treating the scrap
with a mixture of hydrochloric and hydrofluoric acids. The process steps
are: (1) leach the scrap with the mixed acid to remove the oxide,
(2) remove the acid from the scrap with a water wash, and (3) dry the
scrap for further processing.
Energy requirements are not significant. The major waste
generated is a liquid waste consisting of the spent acid mixture. This
spent acid is normally disposed of by neutralization.
The process has little potential for the production of serious
atmospheric problems. However, the potential for water pollution by spent
acids could be significant.
Refining Operation
The scrap pretreatment operation removes primarily the surface
impurities such as the oils and the oxide. Via the smelting refining
operation the scrap is densified and the internal impurities are removed
by vaporization as shown in the segment flowsheet by Process 3.
Vacuum Electric Arc Melting Process (3). In this process, the
clean scrap is melted to obtain molten alloys and the volatile impurities
are removed. The process steps are: (1) charging clean scrap to the
electric furnace, (2) melting the scrap, (3) vaporizing the impurities,
and (4) pouring the molten metal.
Energy required is electricity to operate the process.
The process is conducted in a completely closed system and
wastes generated are well controlled. Therefore, the process has little
potential for the production of pollution problems.
Casting Operation
Casting Process. By this process the molten metal is cast
into ingots.
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C-L63
The process consists of: (1) pouring the molten alloy into
molds and (2) casting.
Energy requirement is that necessary to operate the equipment.
Wastes generated are insignificant and do not present any
pollution problem.
Population of Secondary Titanium Processors
(1) RMI Company
Niles, Ohio
Telephone: (216) 652-9951
(2) Titanium Metals Corporation of American
1140 Bloomfield Avenue
West Caldwell, New Jersey
Telephone: (201) 575-9400
(3) Kawecki Berylco Industries, Inc.
220 East 42nd Street
New York, New York
-------
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C-165
PROCESS DESCRIPTION OF ZINC SEGMENT OF
THE SECONDARY NONFERROUS METALS INDUSTRY
Introduction
The zinc segment of the secondary nonferrous metals industry
consists of those plants that process discarded and scrap materials
for the purpose of recovering zinc. In 1969,^ 376,400 tons of zinc
were recovered. In the recovery of the zinc, waste products—atmos-
pheric emissions, liquid wastes, and solid wastes—are generated which
can cause serious pollution problems.
Raw Materials
The principal sources of zinc scrap as classified by the
Bureau of Mines^ ' are:
New clippings
Old zinc
Engravers' plates
Skimmings and ashes
Sal skimmings
Die-cast skimmings
Galvanizers1 dross
Diecastings
Rod and die scrap
Flue dust
Chemical residues.
In addition to containing metallic zinc or compounds and alloys, thereof,
the scrap contains a wide variety of organic materials such as oil,
grease, lubricants, and electric insulation. Alloying elements commonly
found in the scrap are aluminum, copper, and lead.
(1) Moulds, D. E., Minerals Yearbook, 1969, U. S, Dept. of Interior,
Bureau of Mines, p 1148 (1971).
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C-166
Products
Products from the zinc segment of the secondary nonferrous
metals industry are: (1) specification zinc alloys, (2) zinc ingots
(slab) containing essentially .100 percent zinc, (3) zinc dust, (4) zinc
oxide approaching 100 percent purity, and (5) crude zinc oxide for
reduction to zinc metal by the primary smelters.
Process Description
The products from the zinc segment are recovered from the
various types of scrap zinc employing two manufacturing operations--
scrap pretreatment and refining. These operations and the individual
processes in each operation are shown in the attached segment flowsheet.
Scrap Pretreatment Operation
Zinc scrap is pretreated prior to refining to remove a portion
of the metallic and nonmetallic impurities and to physically prepare
the material for further processing. Three types of preprocessing
(hydrometallurgical, pyrometallurgical, and mechanical) are used.
The pretreatment varies depending on the type of scrap. The individual
pretreatment processes are numbers 1 through 6, as shown in the segment
flowsheet.
Crushing/Screening Process (1). The concentration of
metallic zinc in skimmings/residues is increased by the crushing/
screening process. The process steps involved are: (a) pulverizing
or crushing the skimmings/residues to separate the metallic zinc from
the flux, and (b) screening or pneumatically treating the crushed
material to separate zinc from nonmetallic constituents.
Energy required is that to drive the equipment.
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C-167
The process generates atmospheric emissions and solid wastes.
The atmospheric emissions are composed of dusts from both the
pulverizing (crushing) process step and the screening step. These
emissions contain, in addition to zinc, those materials--nonmetallic
constituents, metallic values such as zinc, aluminum, copper, iron, lead,
cadmium, tin, and chromium and fluxes--separated from the scrap zinc
during the sweating process. Emissions data are not available; however,
based on studies conducted of other industries, the raw emissions
factor is estimated to range from 0.9 to 7.5 lb per ton of skimmings/
residues processed.
The solid wastes generated by this process are nonmetallic
constituents from the screening operation and baghouse dusts, if
emissions from crushing and screening process steps are controlled.
This process produces a small quantity of emissions and is,
therefore, a minor source of pollution.
Kettle Sweating Process (2). The kettle sweating process
separates the metallic zinc from metal attachments, having higher
melting points, and from nonmetallic residues. This is achieved by the
following process steps: (a) charging the scrap into the furnace con-
taining generally a molten heel, (b) melting of zinc fraction of the
scrap, (c) working of charge to effect separation of the zinc,
(d) fluxing to aid in the separation, and (e) skimming to remove
impurities removed by the flux. Afterwards the molten metal may be
removed and cast in blocks for further processing, fed to a
distillation furnace or alloyed to obtain specification composition and
then cast into ingots. Operating temperatures of the kettle-sweating
baths range from 800 to 1000 F. Production is batchwise, with one
batch requiring 6 to 8 hours to complete one heat.
Energy required is the electricity to drive the equipment
and the fuel, generally, natural gas, to melt and keep the zinc
molten. Fuel oil is used as fuel in some cases.
-------
C-168
The process produces significant quantities of potential
environmental pollutants. Atmospheric emissions consist of:
(1) combustion gases (which are separate from the emissions from the
molten metal), and (2) emissions consisting of gases and particulates
from the molten metal. Solid.wastes generated are metal attachments
and skimmings or slag from the flux present in the scrap or that added
to purify the zinc metal and baghouse dusts.
Composition of the particulate atmospheric emissions varies
somewhat depending on the charge. However, in most cases, the emissions
contain ammonium chloride, zinc, aluminum, tin, nickel, copper, iron,
lead, cadmium, magnesium, manganese, and chromium. A typical analysis
is shown in Table C-3. The gases are composed of, in addition to the
combustion products, carbonaceous materials from the rubber, plastic,
and other organic impurities or contaminants in the scrap. Some
carbonaceous materials are also mixed with the particulate emissions.
Emissions factors also vary depending on the composition of '
the charge. When sweating metallic scrap* with zinc chloride as the
flux, raw emissions factor was reported to be 10.8 Ib/ton of scrap
processed. These particulate emissions contained 4, 77, 4, 4, and 10
percent, respectively, of zinc chloride, zinc oxide, water, other metal
chlorides and oxides, and carbonaceous materials. In other cases, the
raw emissions factor for sweating residual scrap** (the flux was
residual zinc chloride) was reported at 24.5 Ib/ton of scrap processed.
Composition of particulate emissions was similar to that from the
sweating of the metallic scrap.
Morphology of the particles is dependent on the type of scrap.
For example, the particle size of the emissions from sweating of residual
scrap ranged from less than 1 micron to greater than 20 microns, whereas
those from sweating of metallic scrap were less than 2 microns. Particle
shape is acicular and/or irregular. Those emissions that are predominately
zinc oxide are composed of primarily acicular particles which is the
* Metallic scrap consists of metallic items, generally in the same
shape as when manufactured or used.
** Residual scrap is composed of residues, skimmings, and other low
grade scrap.
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C-169
TABLE C-3. ANALYSES OF PARTICULATE EMISSIONS
FROM ZINC SWEAT PROCESS ING(2)
Component Percent
ZnCl2 14.5 - 15.3
ZnO 46.9 - 50.0
NH4C1 1.1 - 1.4
A1203 1.0 - 2.7
Fe203 0.3 - 0.6
PbO 0.2
H20 (in. ZnCl2-4H20) 7.7 - 8.1
Oxides of Mg, Sn, Ni, Si, Ca, Na 2.0
Carbonaceous Material 10.0
Moisture (deliquescent) 5.2 - 10.2
(2) Herring, W. 0, Secondary Zinc Industry,
Emission Control Problem Definition Study,
Part 1, Technical Study, APCO, EPA,
Durham, North Carolina.
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C-170
characteristic shape of zinc oxide. Low zinc emissions have an
irregular shape or are composed of a mixture of particle shapes.
Generally, the atmospheric emissions are controlled or
collected using baghouses with orlon filter medium. Collection
efficiencies of approximately 96 percent are reported.
No liquid wastes are generated by the kettle sweating
process unless possibly some cooling water. However, significant
quantities of solid wastes are generated. These wastes are: (1) slag
(skimmings or drosses), (2) high melting attachments, and (3) baghouse
dusts.
Thus, the kettle sweating process is a source of potential
pollution problems if the wastes are not collected and disposed of
properly.
Reverberatory Sweating Process (3). This process separates
or recovers zinc metal from mixed zinc scrap. The recovered impure
zinc is processed further to obtain specification alloys or fed to a
distillation furnace for refining. The process steps are: (a) charging
of furnace, (b) melting of zinc, and (c) removal of unmeltables. In
this process the zinc flows from the furnace as it melts and is collected
in vessels or allowed to flow to the next process in operation.
Energy required for this process is the electricity to drive
the equipment and the gas or fuel oil to fire the furnace. The
reverberatory furnace is direct-fired whereas the kettle furnace is
heated indirectly.
Both atmospheric emissions and solid wastes are generated.
The atmospheric emissions are composed of the combustion gases, gases
or vapors from burning of the organic content of the scrap, and volatile
metallic materials. The particulate emission is the fume volatilized
from, the furnace and dust carried from the furnace by the entrainment
of particles in the furnace exit gases.
Composition of the atmospheric emissions varies depending on
the source and type of scrap. However, in general, the particulate
emission will contain such metals as zinc, aluminum, copper, iron, lead,
-------
C-171
cadmium, manganese, and chromium, in addition to carbonaceous materials
and components from the residual fluxes. The gases contain primarily
carbon dioxide, nitrogen, oxygen, and water, and possible sulfur oxides,
chlorides, and fluorides.
Particulate emission factors vary depending on the type of
scrap. For metallic scrap, raw emissions factor was reported to be
approximately 13 Ib of particulate matter per ton of charge processed,
whereas raw emissions factor for residual scrap was reported to be
(3)
approximately 32 Ib per ton of feed process. Baghouses with orIon
filter media are used to control these emissions.
Particle morphology of atmospheric emissions is the same or
comparable to the morphology of emissions from the kettle furnace.
No liquid wastes are generated. Solid wastes from this
process are: (1) baghouse dusts; (2) skimmings, drosses or slag; and
(3) unmeltable attachments.
The process does produce significant quantities of atmospheric
emissions and solid wastes which could cause pollution problems.
Rotary Sweating Process (4). Zinc metal is separated from
zinc scrap such as die-castings by the rotary sweating process. During
the sweating, the furnace is rotated on its axis. The zinc metal is
collected in a kettle (outside the furnace) and the residue is skimmed
off the molten metal.* The process steps are: (a) charging of furnace,
(b) melting of zinc values, (c) removing (skimming) of residue, and
(d) removing the unmeltables from the furnace. Afterwards, the impure
zinc melt is transferred to a distillation furnace or alloyed and cast
into ingots.
Energy required is the electrical energy to rotate the furnace
and fuel (gas or oil) to heat the furance which is direct fired.
(3) Herring, W. 0., "Secondary Zinc Industry, Emissions Control Problem
Definition Study, Part 1-Technical Study", NASMI, APCO, EPA,
Durham, North Carolina.
'(4) Air Pollution Engineering Manual, U. S. Dept. HEW NAPCA, p 307 (1967)
* No fluxes are added.
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C-172
Potential environmental pollutants generated by this process
are: (1) atmospheric emissions, and (2) solid wastes. The atmospheric
emissions include both gases and particulate emissions. The gases are
composed of those produced by combustion of the fuel and burning of
organic matter contained in the scrap. The particulate emissions
generally are composed of such metal values as are found in the emissions
from the reverberatory sweating process. Included in this list are zinc,
aluminum, copper, iron, lead, cadmium, manganese, and chromium.
Particulate emission factor data are not available. However,
based on reported values from other sweating processes, it is estimated
the raw emission factors will range from 11 to 25 Ib of particulate
matter per ton of feed.
Particulate morphology of the particles should be similar to
the morphology of the particles from other sweating processes.
The solids generated by this process are skimmings, unmeltable
attachments, and baghouse dusts.
The process produces significant quantities of atmospheric
emissions and solid wastes and, therefore, is a potential source of
atmospheric and water pollution problems.
Electric-Resistance Sweating (5). This process is employed
in small plants to recover zinc from clean scrap. The process steps
are: (a) charging of furnace, (b) sweating of zinc, (c) pouring of
zinc melt for subsequent processing, and (d) removing residue from
furnace.
Energy required is the electricity to sweat the zinc.
Potential environmental pollutants are: atmospheric
emissions and solid wastes. Atmospheric emissions are composed of
primarily fume and dust since only clean scrap is used as the source
of zinc and no combustion products are formed. The fume and dust contain
primarily zinc oxide from the oxidation of zinc vapor along with trace
quantities of other heavy metals and possibly a small quantity of
chloride and fluxing materials. The gaseous portion of the emissions
is primarily nitrogen. Emissions are controlled with baghouses, if
pollution controls are used.
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C-173
Particle morphology is the same as that of emissions from
other processes.
Emissions factor is probably low, <10 Ib of fume and dust
per ton of feed processed.
Solid wastes from this process are drosses, if fluxes are
used, unmeltable components of the scrap, and baghouse dusts.
Although this process produces small quantities of atmos-
pheric emission, there is potential atmospheric and water pollution
problems associated with disposal of these materials and with the
process.
Muffle Sweating Process (6). Zinc metal is recovered from
zinc scrap materials by the muffle sweating process. The process steps
are: (a) charging of furnace, (b) sweating of zinc values, (c) tapping
of furnace to remove molten zinc for subsequent refining or alloying,
and (d) removing residue with a shaker screen to separate the dross
from the unmeltable attachments.
Energy required is the fuel--gas or oil--to heat the muffle
furnace which is indirectly fired.
Potential pollutants from this process are: (1) atmospheric
emissions composed of gases from the combustion of the fuel and from the
sweating chamber and particulate emissions from the sweating chamber,
and (2) solid wastes--drosses and unmeltable attachments. The gaseous
emissions include those from the combustion chamber which are emitted
separately to the atmosphere and those from the sweating chamber. The
combustion gases contain primarily carbon .dioxide, nitrogen, unburned
fuel, and possibly trace quantities of heavy metals and sulfur oxides
if oil is used as the source of fuel. Those from the sweating chamber
are composed of a small quantity of gases from air leaking into the
chamber and from combustion or decomposition of organic compounds added
with the scrap.
Composition of the particulate emissions from the sweating
chamber will vary depending on the type of scrap but, in general,
contains the metals found in particulate emissions from other sweating
processes, with the major component being zinc.
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C-174
Particle morphology of the participates is the same as that
of emissions from other processes.
Emission factors for the muffle furnace process are not
available. However, they are estimated to range from approximately
10.8 to 32 Ib per ton of feed processed. Baghouses are used to control
the emissions. A cyclone may be used in series with the baghouse.
The solid wastes generated are drosses, baghouse dusts, and
unmeltable attachments.
The process generates a considerable quantity of atmospheric
emissions and solid wastes, and thus is a source of pollution problems.
Sodium Carbonate Leaching Process (7). The sodium carbonate
leaching process removes the nonmetallic contaminants from skimmings
and residues and converts the zinc values to zinc oxide which can be
reduced to zinc metal. The process steps are: (a) crushing to make
the scrap more amenable to leaching, (b) washing with water to separate
nonmetallic contaminants and recover metallic zinc, (c) treating the
aqueous stream with sodium carbonate to precipitate the zinc values,
(d) drying the precipitate to remove the water, and (e) calcining to
convert zinc hydroxide to zinc oxide. The product (zinc oxide) is
shipped to a primary smelter for reduction to zinc metal.
Energy required for this process is electrical energy to
drive the equipment and fuel, either gas or oil, to dry and calcine
the zinc hydroxide.
The process produces waste products — atmospheric emissions,
liquid wastes and solid wastes—in modest quantities. The atmospheric
emissions consisting of both gases and particulate matter are produced
during the crushing, drying, and calcining process steps. The gases are
from the crushing step and present no problem since they primarily
consist of air. Those from the drying and calcining steps contain
primarily the combustion gases and water vapor. Since any residual zinc
chloride is vaporized during the calcination, the gases may also contain
hydrogen chloride and zinc chloride. The particulate matter consists
primarily of zinc oxide fume contaminated with other metal values either
-------
C-L75
vaporized with the zinc oxide or entrained in the gaseous stream. The
atmospheric emissions are controlled with baghouses.
Liquid wastes are generated in steps (b) and (c). These
wastes contain sodium chloride, sodium carbonate, and other water-
soluble compounds not precipitated by the sodium carbonate.
Because of the corrosive nature of the atmospheric emissions,
allowing them to escape to the environment could cause pollution
problems. Liquid wastes may cause water pollution problems if not
treated before discharge.
Refining Operation
The pretreated zinc scrap still contains a wide variety of
metallic and nonmetallic contaminants which are removed in the refining
operation to produce pure zinc ingots, zinc dust, zinc oxide, and
specification zinc alloys. These products are produced by the processes
8 through 12 as shown in the attached flowsheet entitled "Zinc Segment
of the Secondary Nonferrous Metals Industry".
Retort Distillation Process (8). This process produces pure
zinc ingots and pure zinc dust from pretreated zinc scrap--molten
zinc-rich metal from the sweat furnace or cast zinc-rich metal ingots
from a sweating process--and/or zinc dross. The process steps are:
(a) charging the furnace with the pretreated zinc scrap or dross,
(b) melting the charge, (c) distilling the zinc, (d) condensing the
zinc vapor rapidly to produce zinc dust or slowly to produce pure
liquid zinc. Afterwards, the zinc metal is removed and cast into
ingots (slabs). Zinc dust, if the final product, is removed and packaged.
The energy required for this process is the fuel--gas or oil--
to heat the furnace which is indirectly fired.
This process produces significant quantities of atmospheric
emissions and solid wastes. Sources of atmospheric emissions are the
retort opening,- combustion chamber, the condenser, and casting of ingots.
Emissions as zinc oxide fumes are evolved from the retort opening
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C-176
(charging port) during removal of the hot residue from the retort after
a distillation heat and recharging of the retort for the next distillation.
These emissions contain primarily zinc oxide along with aluminum, copper,
and other metal values found in the residues. Raw emissions factor from
this source and the condenser as discussed below are estimated to be 45 Ib
of particulates per ton of zinc distilled. Emissions factor may be
much higher due to leaks in the grout seal around the condenser neck.
Particle size of the fumes is estimated to range from approxi-
mately 0.05 to 1.0 micron. Since the fumes are primarily zinc oxide
resulting from air oxidation of zinc metal, particle shape is acicular,
the characteristic shape of zinc oxide.
Combustion gases which are emitted separately from the other
emissions contain carbon dioxide, unburned fuel and nitrogen, and .
possibly trace quantities of heavy metals if oil is used as the fuel.
During distillation of zinc, the condenser must be kept
positive pressure to prevent air from entering the condenser and con-
taminating the zinc metal with oxygen. To ensure that there is a
positive pressure, a small hole, called a "speise" hole, is provided
through which a small amount of zinc vapor is allowed to escape contin-
uously into the atmosphere where it reacts with oxygen. These emissions
(fumes) are essentially 100 percent zinc oxide. The particles, acicular
in shape, are extremely fine, i.e., approximately 0.05 to 1 micron.
Only a small amount of atmospheric emissions is formed during
the pouring and casting processing steps. Emission factors are estimated
to range from 0.4 to 0.8 and 0.2 and 0.4 Ib of particulates, respectively,
per ton of zinc produced. These data are based on similar operations in
other industries. These emissions are emitted as fine particulates with
the same particle size and shape as those from the condenser.
Solid wastes generated by the retort distillation process are
the distillation residues and the particulate matter, if collected, in
the atmospheric emissions. The atmospheric emissions are primarily zinc
(5) Vandegriff, A. E., et al., Particulate Pollutant System Study,
Volume 1-Mass Emissions, Midwest Research Institute, Kansas City,
Missouri, p 179 (May 1, 1971).
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C-177
oxide, whereas the distillation residues are composed of heavy metals
such as residual zinc (10 to 50 percent) not removed by the distillation
process and contaminants such as aluminum, copper, lead, and fluxes not
removed during the pretreatment process.
In view of the quantity of atmospheric emissions and solid
wastes generated by the retort distillation process, serious pollution
problems may arise if the atmospheric emissions are not collected and
the wastes are not disposed of by a nonpolluting method.
Muffle Distillation Process (9). This process produces pure
zinc ingots, generally from pretreated zinc scrap. However, in some
cases, untreated scrap such as zinc die-castings may be substituted for
pretreated scrap. This process may be operated continuously whereas the
retort distillation process is batch. The process steps involve:
(a) continuously adding molten zinc from a melting pot or a sweating
furnace to the muffle section, (b) continuously distilling and condensing
the pure zinc, (c) periodically tapping the zinc from the condenser into
the molds, (d) casting the zinc ingots, and (e) periodically removal
of residue from muffle.
Energy utilized by this process is fuel oil or gas to supply
the heat for vaporization of the zinc.
The process produces significant quantities of atmospheric
emissions and solid wastes. Sources of atmospheric emissions are the
combustion gases, distillation residues, pouring and casting of the
ingots, and the orifice in the condenser. Emission factors, composition
of emissions, and morphology of particulates are the same for both
distillation processes. Atmospheric emissions may be controlled with
baghouses alone or in series with cyclones.
Solid wastes generated are distillation residues and baghouse
dusts which are essentially of the same composition as the solid wastes
from the retort distillation process.
Thus, the process is a source of pollution problems.
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C-178
Retort Distillation/Oxidation Process (10). Zinc oxide
produced by the retort distillation/oxidation process involves vapor
oxidation of zinc metal. The process steps in this process are the
same as for the retort distillation process except zinc vapor from the
retort is discharged through an orifice into a stream of air where zinc
oxide is formed inside a refractory-lined chamber. The combustion gases
from oxidation of the metallic zinc vapors and excess air carry the
zinc oxide to a baghouse collector where the zinc oxide is collected.
The combustion gases and excess air pass through the baghouse into the
surrounding atmosphere.
Energy required for this process is the fuel--gas or oil--to
vaporize the zinc metal.
Waste products from this process are atmospheric emissions and
solid wastes. The atmospheric emissions, which consist of gases and
fumes, are emitted to the atmosphere from the retort opening (charging
port), baghouse, and combustion (furnace) chamber. Those from the retort
opening result from oxidation of the hot residue removed after a dis-
tillation heat and upon charging of the retort with molten zinc for the
next distillation heat. See the discussion on the retort distillation
process for pertinent data on composition of emission, emission factors,
and morphology of the particles.
Combustion gases from the retort furnace consist of primarily
carbon dioxide, nitrogen, and unburned fuel. If oil is used as the
fuel, the gases may also contain sulfur oxides, chlorides, and trace
amounts of heavy metals.
Atmospheric emissions from the baghouse contain pure zinc
oxide fume and the gases from burning of the zinc with air. The zinc
oxide may contain trace quantities of heavy metals such as cadmium,
depending on the purity of the feed. The particles of zinc oxi.de are
very small, ranging in size from approximately 0.05 to about 1.0 micron.
The particle shape is predominantly acicular, i.e., needle-like.
Emission factors for the baghouse are estimated at 20 to 40 Ib
of zinc oxide per ton of oxide produced. These data are calculated based
on a collection efficiency of 98 to 99 percent.
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C-179
Solid waste generated is the distillation residue remaining
in the retort after removal of the zinc. This residue contains 10 to 50
percent zinc and contaminants — aluminum,' copper, lead, and residual
flux--not removed from the zinc scrap during the pretreatment operation.
Thus, the retort distillation/oxidation process is a source of
potential environmental pollutants which can cause problems.
Muffle Distillation/Oxidation Process (11). This process
produces zinc oxide from pretreated zinc scrap. The process steps are
the same as for the muffle distillation process except that in the
production of zinc oxide, zinc vapors are allowed to escape through an
orifice at the top of the first chamber of the condenser and are burned
or oxidized in the air. The resulting zinc oxide is transported by the
combustion gases and excess air through conduits and collected in a
baghouse.
Energy required for this process is gas or oil to heat the
muffle furnace.
The potential environmental pollutants are: (1) atmospheric
emissions, and (2) solid wastes. Sources of atmospheric emissions are:
(1) the furnace combustion chamber which is separate from the other
sources as the furnace is indirectly fired, (2) muffle opening
(charging port), and (3) baghouse. See discussion on the muffle
distillation process for details concerning composition of emissions,
emission factors and morphology on particulates from sources (1) and
(2), and the above discussion on the retort distillation/oxidation
process for pertinent data on composition of emissions, emission factors,
and morphology of particles for conversion of zinc to zinc oxide and
subsequent collection of the zinc oxide.
Solid waste generated by the muffle distillation/oxidation
process is the distillation residue from the muffle. This residue has
the same composition as the residue from the retort distillation/
oxidation process.
Based on these data, this process is a source of pollution
problems.
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C-180
Alloying Process (12). The alloying process produces zinc
alloys from pretreated scrap. The process steps are: (a) melting the
pretreated scrap, (b) adding the alloying agent to molten metal,
(c) homogenizing the mixture, (d) pouring the melt into ingot molds,
and (e) casting the ingot. In many cases, the alloying process is
combined with the sweating process, whereby the molten pretreated scrap
is used directly to produce the alloy.
Energy requirement for the Alloying Process is fuel—oil or gas
to keep the melt molten or to melt pretreated scrap ingots.
The process produces atmospheric emissions and solid wastes.
If alloying is carried out using molten zinc from a sweating furnace,
the atmospheric emissions contain zinc oxide, small amounts of the
alloying agent, and the flux cover. If pretreated scrap ingots are
used as the source of zinc, the atmospheric emissions will contain,
in addition to the particulate matter, gaseous emissions from combus-
tion of the fuel. Particulate matter may be controlled using a baghouse;
however, in many cases, no pollution control is employed.
Solid waste is the flux cover used to protect the melt. Flux
covers commonly used are carbon or zinc chloride.
The process produces minor quantities of emissions and solid
wastes and, therefore, is not a major source of pollution.
Graphite Rod Resistor Distillation Process (13). This process
produces zinc dust from pretreated scrap ingots. The process steps are:
(1) charge the ingot or melt to furnace, (2) heat with electric power,
and (3) collect zinc dust as distillate using closed-loop water cooling
system.
Electric energy is used in significant quantities to vaporize
the zinc.
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C-L81
The process generates vapors containing traces of zinc, zinc
oxide, lead, and lead oxide.
The pollution potential of these vapors is not significant because
the metal content is recovered in baghouses and returned to the process.
The process has no pollution potential.
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C-182
Population of Secondary Zinc Processors
(1) Apex Smelting Company
Division of AMAX Aluminum Company
2515 West Taylor Street
Chicago, Illinois
Telephone: (312) 332-2214
(2) Belmont Smelting and Refining
Works, Inc.
320 Belmont Avenue
Brooklyn, N.Y. 11207
(3) Colonial Metals Company
Columbia, Pennsylvania
Telephone: (717) 684-2311
(4) Empire Metal Company
820 E. Water Street
Syracuse, New York 13210
Telephone: (315) 478-6950
(5) Florida Smelting Company
2640 Capitola Street
Jacksonville, Florida
Telephone: (904) 353-4317
(6) Freedman Metal Company
310 McGinnis Boulevard
Brooklyn, N.Y. 11222
Telephone: EV9-4131
(7) General Copper and Brass Company
Post Office Box 5353-D
Philadelphia, Pennsylvania
Telephone: (215) SA6-7111
(8) General Smelting Company
Division of Wabash Smelting, Inc.
2901 EW Moreland Street
Philadelphia, Pennsylvania
Telephone: GA3-3200
(9) Gettysburg Foundry
Specialties Company
Post Office Box 421
Gettysburg, Pennsylvania 17325
Telephone: 335-5616
(10) Gulf Reduction Corporation
6030 Esperson Street
Houston, Texas
(11) Holtzman Metal Company
5223 McKissock Avenue
St. Louis, Missouri 63147
Telephone: (314) CI1-3280
(12) Inland Metals Refining Co.
651 E. 119th Street
Chicago, Illinois 60628
(13) Jordan Company
Salvage Reclamation Division
5000 S. Merrimac Avenue
Chicago, Illinois 60638
Telephone: (312) P07-6570
(14) Metchem Research, Inc.
Radcliff and Monroe Streets
Bristol, Pennsylvania
Telephone: (215) 848-0820
(15) National Metal and Smelting
Company
210 NW Fourth Street
Fort Worth, Texas
(16) North American Smelting
Company
Marine Terminal
Post Office Box 1952
Wilmington, Delaware
Telephone: OL4-9901
(17) Pacific Smelting Company
22219 Southwestern Avenue
Torrance, California
Telephone: SP5-3421
(18) Paragon Smelting Corporation
36-08 Review Avenue
Long Island City, N.Y. 11101
Telephone: (212) RA9-3481
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C-183
(19) Roth Smelting Company
Thompson Road
Syracuse, New York
(20) George Sail Metals Company, Inc.
2255 East Butler Street
Philadelphia, Pennsylvania 19137
Telephone: (215) PI3-3900
(21) Sandoval Zinc Company
3649 South Albany Avenue
Chicago, Illinois 60632
Telephone: FR6-1900
(22) SIPI Metals Corporation
1722 N. Elston Avenue
Chicago, Illinois
(23) Solken-Galamba Corporation
Second and Riverview Streets
Kansas City, Kansas 66118
Telephone: (913) MA1-4100
(24) St. Joseph Lead Company
250 Park Avenue
New York 10017
Telephone: YU6-7474
(25) U.S. Metal Products Company
Post Office Box 1067
Erie, Pennsylvania 16512
Telephone: (814) 838-2051
(26) Hyraan Viener & Sons
Post Office Box 573
Richmond, Virginia 23205
Telephone: (703) 648-6563
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S 7 6 5 + 4 3 2 1
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C-185
PROCESS DESCRIPTION OF THE ZIRCONIUM SEGMENT
OF THE SECONDARY NONFERROUS METALS INDUSTRY
There are two zirconium processors in the United States. Most
of their product is used in nuclear reactors in the civil and military
applications.
The scrap zirconium market is very small. In fact, the two
processors do not, as a rule, purchase any scrap except those routinely
generated in their regular customer operations. This state prevails
because scrap from unknown sources makes the control of product quality
very difficult.
Production volume of zirconium (primary and secondary) is a
proprietary secret. Estimates, however, range from 3 to 5 million pounds.
The product sells at about 10 to 15 dollars per pound.
As in the case of indium, hafnium, and beryllium, currently
employed product process details are not available. However, since the
total market is very small and the product is very expensive, the processors
are economically constrained to maximize recovery. This insures low
ambient or indoor emissions of zirconium.
Zirconium is not a toxic material.
U. S. producers of zirconium do not seem to be interested in
outside help in their research and development activities. This trend may
not change in the foreseeable future.
Population of Secondary Zirconium Processors
(1) Amax Specialty Metals Division
American Metal Climax, Inc.
6000 Hake Road
Akron, New York 14001
Telephone: (716) 542-5454
(2) Teledyne Wha Chang
P. 0. Box 460-T
Albany, Oregon
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C-186
TECHNICAL REPORT DATA
(Please rcail Imimctions on llic reverse before
I. REPORT NO.
EPA-650/2-74-048
2.
3. RECIPIENT'S ACCESSION NO.
4. TITLE AND SUBTITLE
Development of an Approach to Identification of
Emerging Technology and Demonstration
Opportunities
5. REPORT DATE
May 1974
6.PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
H.Nack, K. Murthy, E.Stambaugh, H. Carlton, and
G. R.Smithson, Jr.
8. PERFORMING ORGANIZATION RtPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Battelle--Columbus Laboratories
505 King Avenue
Columbus, Ohio 43201
10. PROGRAM ELEMENT NO.
1AB015; ROAP 21AFH-016
11. CONTRACT/GRANT NO.
R-802291
12. SPONSORING AGENCY NAME AND ADDRESS
EPA, Office of Research and Development
NERC-RTP, Control Systems Laboratory
Research Triangle Park, NC 27711
13. TYPE OF REPORT AND PERIOD COVERED
Final; Through 5/25/74
14. SPONSORING AGENCY CODE
15. SUPPLEMENTARY NOTES
16. ABSTRAC1
The report gives results of a study to develop methodology for characterizing
major industries from the standpoint of their present environmental impact and
for assessing the probable effect of emerging process technology on environmental
considerations. It describes a systematic method for separating the industries into
process modules. It demonstrates the applicability of this approach, using as
examples the petroleum refining and secondary nonferrous metals industries, each
with substantially different characteristics. It also reports an approach utilizing
expert opinion for rapid identification of emerging technology, and discusses
technology being developed in the two industries.
7.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
6.IDENTIFIERS/OPEN ENDED TERMS
C. COSATI Picld/Croup
Air Pollution
Environmental
Engineering
Processing
Industries
Petroleum Refining
Metal Industry
Industrial Wastes
\ir Pollution Control
Stationary Sources
Methodology
nvironmental Impact
merging Technology
Secondary Nonferrous
Metals
13B, 11F
05E
05C
13H
8. DISTRIBUTION STATEMENT
Unlimited
19. SECURITY CLASS (This Report)
Jnclassified
21. NO. OF PAGES
273
20. SECURITY CLASS (Thispage)
Unclassified
22. PRICE
EPA Form 2220-1 (9-73)
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