MULTIMEDIA ENVIRONMENTAL ASSESSMENT
OF THE SECONDARY NONFERROUS
METAL INDUSTRY
VOLUME II: INDUSTRY PROFILE
by:
W. M. Coltharp W. E. Corbett
G. C. Page N. P. Phillips
Radian Corporation
8500 Shoal Creek Blvd.
Austin, Texas 78766
EPA Contract No. 68-02-1319, Task No. 49
EPA Task Officer: Margaret J. Stasikowski
ENVIRONMENTAL PROTECTION AGENCY
Industrial and Environmental Research Laboratory
5555 Ridge Avenue
Cincinnati, Ohio 45268
INDUSTRIAL AND ENVIRONMENTAL RESEARCH LABORATORY
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
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FOREWARD
Man and his environment must be protected from the
adverse effects of pesticides, radiation, noise, and other forms
of pollution, and the unwise management of solid wastes. Efforts
to protect the environment require a focus that recognizes the
interplay between the components of our physical environment --
air, water, and land. The Industrial and Environmental Research
Laboratory contributes to this multidis ciplinary focus through
programs engaged in:
• studies on the effects of environmental contaminants
on the biosphere, and
• a search for ways to prevent contamination and to
recycle valuable resources.
¦In this report, the results of a multimedia environ-
mental assessment of the environmental impact of the secondary
nonferrous metal industry are presented. These results include
the characterization of the industry and its segments, the
evaluation of the industry's multimedia environmental problems,
and the evaluation of pollution control technology used in the
industry. As a result of this study, key information and
research needed to develop programs which will lead to more
effective control of environmental impacts from reprocessing""
nonferrous metals were identified.
ii
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ABSTRACT
The major objectives of this study were to perform
multimedia environmental assessment of the secondary nonferrous
metal industry and to identify research, development, and demon-
stration needs to more effectively control the environmental
impacts associated with this industry.
The results and conclusions of this study included:
(a) characterization of the industry and its segments, (b)
evaluation of the industry's environmental problems, and (c)
evaluation of the pollution control technology. The secondary
nonferrous metal industry is comprised of 334 companies which
are mostly located around urban areas. The industry can be
divided into eighteen segments based on the type of metals pro-
cessed. Of these segments, the Aluminum, Copper, Brass and Bronze,
Lead/Antimony, and Zinc Segments account for approximately 95%
of the total industry production.
The pollution problems associated with this industry
were identified and it was determined that many processes used
in the industry were similar with similar environmental impacts.
Five specific processes were identified as being major sources of
multimedia pollution: (a) Reverberatory Smelting with chlorine/
fluorine demagging (Aluminum Segment), Insulation Burning (Copper,
Brass and Bronze Segment), Reverberatory/Blast Furnace Smelting
(Lead/Antimony Segment), Battery Breaking (Lead/Antimony Segment),
and Electrolytic Refining (Copper, Brass and Bronze Segment).
The multimedia emissions from many of the processes used
in this industry can have very hazardous effects on health and the
environment. There are at least 143 toxic and hazardous compounds,
many of which are suspected carcinogens, that can be emitted.
xix
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Health and epidemiological studies have also shown toxic effects
of these emissions on health and the environment.
Based on the results, recommendations for key secondary
nonferrous metal industry research needs were source characterization
and development and demonstration needs. The degree of source
characterization required for each process would depend on the
amounts and toxicity of the waste streams. Development and
demonstration needs included process modifications, and retrofit
pollution control technologies.
This report was submitted in fulfillment of EPA Contract
No. 68-02-1319, Task No. 49 by Radian Corporation under the sponsor-
ship of the U.S. Environmental Protection Agency. This report covers
the period December 1, 1975 to June 1, 1976 and work was completed as
of November 1, 1976.
iv
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CONTENTS
Page
FOREWARD ii
ABSTRACT iii
1.0 INTRODUCTION 1
2.0 INDUSTRY OVERVIEW 3
3.0 SECONDARY NONFERROUS METAL INDUSTRY SUMMARIES .. 8
3.1 Secondary Aluminum Segment 10
3.1.1 Segment Description - Secondary
Aluminum 10
3.1.2 Segment Analysis - Secondary
Aluminum 16
3.1.3 Environmental Impact - Secondary
Aluminum 57
3.2 Secondary Copper, Brass and Bronze Segment.. 65
3.2.1 Segment Description - Secondary
Copper, Brass and Bronze 65
3.2.2 Segment Analysis - Secondary
Copper 72
3.2.3 Environmental Impact - Secondary
Copper, Bronze and Brass 117
3.3 Secondary Lead/Antimony Segment 132
3.3.1 Segment Description - Secondary
Lead/Antimony 132
3.3.2 Segment Analysis - Secondary
Lead/Antimony 137
3.3.3 Environmental Impact - Secondary
Lead/Antimony 165
3.4 Secondary Zinc Segment 179
3.4.1 Industry Description - Secondary
Zinc 179
3.4.2 Segment Analysis - Secondary Zinc ....185
3.4.3 Environmental Impact - Secondary Zinc.225
v
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CONTENTS (CONTINUED)
Page
3.5 Secondary Beryllium Segment 232
3.5.1 Segment Description - Secondary
Beryllium 232
3.5.2 Segment Analysis - Secondary
Beryllium 233
3.5.3 Environmental Impact - Secondary
Beryllium 234
3.6 Secondary Cadmium Segment 236
3.6.1 Segment Description - Secondary
Cadmium . 236
3.6.2 Segment Analysis - Secondary
Cadmium . 237
3.6.3 Environmental Impact - Secondary
Cadmium 245
3.7 Secondary Cobalt Segment 247
3.7.1 Segment Description - Secondary
Cobalt 247
3.7.2 Segment Analysis - Secondary
Cobalt 248
3.7.3 Environmental Impact - Secondary
Cobalt 256
3.8 Secondary Germanium Segment 258
3.8.1 Segment Description - Secondary
Germanium 258
3.8.2 Segment Analysis - Secondary
Germanium 259
3.8.3 Environmental Impact - Secondary
Germanium 264
3.9 Secondary Hafnium 266
3.9.1 Segment Description - Secondary
Hafnium 266
3.9.2 Segment Analysis - Secondary
Hafnium 266
3.9.3 Environmental Impact -
Secondary Hafnium. 267
vi
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CONTENTS (CONTINUED)
Page
3.10 Secondary Indium Segment 268
3.10.1 Segment Description -
Secondary Indium 268
3.10.2 Segment Analysis - Secondary
Indium 268
3.10.3 Environmental Impact -
Secondary Indium 269
3.11 Secondary Magnesium Segment 271
3.11.1 Segment Description -
Secondary Magnesium 271
3.11.2 Segment Analysis - Secondary
Magnesium 272
3.11.3 Environmental Impact -
Secondary Magnesium 278
3.12 Secondary Mercury Segment 280
3.12.1 Segment Description -
Secondary Mercury 280
3.12.2 Segment Analysis - Secondary
Mercury 283
3.12.3 Environmental Impact -
Secondary Mercury 298
3.13 Secondary Nickel Segment 303
3.13.1 Segment Description -
Secondary Nickel 303
3.13.2 Segment Analysis - Secondary
Nickel 305
3.13.3 Environmental Impact -
Secondary Nickel 315
3.14 Secondary Precious Metals Segment 318
3.14.1 Segment Description -
Secondary Precious Metals 318
vii
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CONTENTS (CONTINUED)
IM1
3.14.2 Segment Analysis -
Secondary Precious Metals 320
3.14.3 Environmental Impact -
Secondary Precious Metals 330
3.15 Secondary Selenium Segment 333
3.15.1 Segment Description -
Secondary Selenium 333
3.15.2 Segment Analysis - Secondary
Selenium 334
3.15.3 Environmental Impact -
Secondary Selenium 342
3.16 Secondary Tin Segment 345
3.16.1 Segment Description -
Secondary Tin 345
3.16.2 Segment Analysis -
Secondary Tin 347
3.16.3 Environmental Impact -
Secondary Tin 363
3.17 Secondary Titanium Segment 367
3.17.1 Segment Description -
Secondary Titanium 367
3.17.2 Segment Analysis -
Secondary Titanium 368
3.17.3 Environmental Impact -
Secondary Titanium 380
3.18 Secondary Zirconium Segment 383
3.18.1 Segment Description -
Secondary Zirconium 383
3.18.2 Segment Description -
Secondary Zirconium 383
viii
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CONTENTS (CONTINUED)
?*ge
4.0 NOISE POLLUTION 385
4.1 Noise Emissions 385
4.2 Noise Control 385
5.0 POLLUTANT HEALTH AND ENVIRONMENTAL
IMPACTS .... 389
REFERENCES 400
ix
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LIST OF FIGURES
(Continued)
Figure No. Title Page
2.0-2 Company Location Map For The Secondary Non-
ferrous Metal Industry 4
3.1-1 Process Flow Diagram For The Aluminum Segment
Of The Secondary Nonferrous Metal Industry 18
3.2-1 Process Flow Diagram For The Copper, Brass,
And Bronze Segment Of The Secondary Nonferrous
Metal Industry .73
3.3-1 Process Flow Diagram For the Lead/Antimony
Segment Of The Secondary Nonferrous Metal
Industry 138
3.4-1 Process Flow Diagram For The Zinc Segment
Of The Secondary Nonferrous Metal Industry 186
3.6-1 Process Flow Diagram For The Cadmium Segment
Of The Secondary Nonferrous Metal Industry 238
3.7-1 Process Flow Diagram For The Cobalt Segment Of
The Secondary Nonferrous Metal Industry 249
3.8-1 Process Flow Diagram For The Germanium Segment
Of The Secondary Nonferrous lletal Industry 260
3.10-1 Process Flow Diagram For The Indium Segment Of
' The Secondary Nonferrous Metal Industry 270
3.11-1 Process Flow Diagram For The Magnesium Segment
Of The Secondary Nonferrous Metal Industry 273
3.12-1 Process Flow Diagram For The Mercury Segment
Of The Secondary Nonferrous Metal Industry ...... 284
3.13-1 Process Flow Diagram For The Nickel Segment
Of The Secondary Nonferrous Metal Industry 308
x
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LIST OF FIGURES
(Continued)
Figure No. Title Page
3.14-1 Process Flow Diagram For The Precious Metals
Segment Of The Secondary Nonferrous Metal
Industry 321
3.15-1 Process Flow Diagram For The Selenium Segment
Of The Secondary Nonferrous Metal Industry 335
3.16-1 Process Flow Diagram For The Tin Segment Of
The Secondary Nonferrous Metal Industry 348
3.17-1 Process Flow Diagram For The Titanium Segment Of
The Secondary Nonferrous Metal Industry 369
xi
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LIST OF TABLES
Table No. Title Page
2,0-1 Population and Production of Segments Within
The Secondary Nonferrous Metal Industry 6
2.0-2 Quantities and Costs of Fuels Purchased By The
Secondary Nonferrous Metal Industry In 1973..... 7
3.1-1 U.S. Consumption Of Aluminum Scrap and Sweated
Pig In 1973 13
3.1-2 A.S.R.I. Aluminum Scrap Classifications 14
3.1-3 Production Of Secondary Aluminum Alloys By
Independent Smelters In 1973 17
3.1-4 Chemical Analysis Of A Typical Rotary Aluminum
Furnace Slag 30
3.1-5 Typical Analyses Of Settled Wastewaters From
Aluminum Residue Leaching Operations 33
3.1-6 Particle Size Data - Aluminum Sweating Furnace..36
3.1-7 Character of Wastewater from Molten Metal
Cooling and Quenching 44
3.1-8 Scrubber Collection Efficiencies For Emissions
From Secondary Aluminum (Chlorinated)
Reverberatory Smelters 46
3.1-9 Average Particulate Collection Efficiency
Obtained By Using Various Devices On Emissions
From Secondary Aluminum (Chlorinated)
Reverberatory Smelters 47
3.1-10 Character of Cooling Wastewater From Aluminum
(Chlorine) Reverberatory Furnaces , . . 48
3.1-11 Character of Untreated Wastewater From
Chlorination Fume Scrubbing ,49
3.1-12 Effluent Limitations For Treated Fume Scrubber
Wastewater Generated During Chlorine Demagging
To Be Achieved by July 1, 1977, Based On The
Best Practicable Control Technology Currently
Available . 59
xii
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LIST OF TABLES
(Continued)
Table No. Title Page
3.1-13 Effluent Limitations For Treated Wastewater From
Residue Milling To Be Achieved By July 1, 1977,
Based On The Best Practicable Control Technology
Currently Available 60
3.1-14 Process Pollutant and Control Summary -
Aluminum Segment 61
3.2-1 Domestic Consumption Of And Recovery From
Purchased New And Old Copper-Base Scrap In
1971 Through 1973 67
3.2.2 National Association Of Secondary Materials
Industries Classifications For Copper-Bearing
Scrap Materials 69
3.2-3 Nominal Chemical Specifications For Brass And
Bronze Ingot Institute Standard Alloys 70
3.2-4 Character of Wastewater From Slag Quenching And
Granulation Or Slag Milling After Settling 80
3.2-5 'Wire Incineration Furnace Operating Parameters.... 83
3.2-6 Wire Incinerator Effluents (Typical Rubber-
Covered Wire Charge) 85
3.2-7 Character Of Wastewater From Molten Metal Cooling
And Quenching 101
3.2-8 Typical Electrolytic Copper Refining Parameters ... 108
3.2-9 Character of Wastewater From Electrolytic
Refining (Treated Before Discharge3) 110
3.2-10 Air Pollution Control Processes Used By Smelters
And Refiners Of Secondary Brass And Bronze and
Secondary Copper 118
3.2-11 Summary Of Wastewater Handling Practice and
Disposition Used By Secondary Copper Industry ....118
xiii
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LIST OF TABLES
(Continued)
Table No. Title Page
3.2-12 Process Pollutant And Control 'Summary -
Copper, Brass, and Bronze Segment 120
3.3-1 Consumption Of Lead Scrap In 1973 134
3.3-2 Chemical Requirements For Soft Lead 136
3.3-3 Process Pollutant And Control Summary -
Lead/Antimony Segment 170
3,3-4 Major Sources Of Air Emissions In The Secondary
Lead Industry 175
3.3-5 Efficiencies of Particulate Control Equipment
Associated With Secondary Lead Smelting Furnaces ... 177
3.4-1 Grades-Of Zinc Scrap and Drosses 181
3.4-2 Consumption Of New and Old Zinc Scrap In The
United" States In 1973 183
3.4-3 -Secondary Zinc Products Produced In 1975 185
3.4-4 Emission Factors For P.everberatory Sweating 189
3.4-5 Emissions From Zinc Reverberatory Sweating Furnace
Controlled By Baghouse 190
3.4-6 Analyses Of Particulate Emissions From Zinc
Sweat Processing . 197
3.4-7 Process and Pollutant Control Summary -
Zinc Segment 227
3.5-1 Process Pollutant and Control Summary -
Beryllium Segment 235
3.6-1 Process Pollutant and Control Summary -
Cadmium Segment 246
3.7-1 Process Pollutant and Control Summary -
Cobalt Segment 257
xiv
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LIST OF TABLES
(Continued)
Table No. Title Page
3,8-1 Process Pollutant and Control Summary -
Germanium Segment 265
3.11-1 Process Pollutant and Control Summary -
Magnesium Segment 279
3.12-1 U.S. Mercury Consumption And Production In
1974 And 1975 280
3.12-2 Mercury Consumed In The United States In 1973 .... 281
3.12-3 Mercury Emissions By Source In 1968 298
3.12-4 Process Pollutant and Control Summary -
Mercury Segment . 301
3.13-1 Consumption Of New And Old Scrap In The United
States In 1973 304
3.13-2 Nickel Recovered From Nonferrous Scrap Process
In The United States 306
3.13-3 Process Pollutant and Control Summary -
Nickel Segment 316
3.14-1 Production Of Precious Metals
319
3.14-2 Process Pollutant and Control Summary -
Precious Metals Segment 331
3.15-1 Major Uses of Selenium 333
3.15-2 Process Pollutant and Control Summary -
Selenium Segment 343
3.16-1 Process Pollutant and Control Summary -
Tin Segment 364
3.17-1 Process Pollutant and Control Summary -
Titanium Segment 381
4.1-1 Sound Pressure Levels For Selected Equipment Items.386
xv
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LIST OF TABLES
(Continued)
Table No. Title Page
4,2-1 Sources And Abatement Techniques For Noise
Pollution 388
5.0-1 Preliminary Pollutant Health and Environmental
Impact Table 392
xv i
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1.0
INTRODUCTION
In this report, a multimedia (air, water, solid waste
and noise) environmental assessment of the secondary nonferrous
metal industry is presented. In Volume I, the results and con-
clusions of the study are summarized and recommendations for
current research needs in the secondary industry are discussed.
In this volume, a detailed summary is presented of the results of
the industry characterization and environmental assessment sub-
tasks .
A general overview of the secondary nonferrous metal
industry is presented in Section 2.0. In Section 3.0, a series
of 18 industry description documents are presented, one for each
of the secondary industry segments which are identified in Section
2.0.
Within each industry description, an overview of the
segment, an analysis of its processes and a summary of its multi-
media environmental impacts are presented. An exception to this
approach is represented by the method of presenting the noise
pollution problem. Because the features of this impact category
are similar for all segments, this subject is discussed on an
industry-wide basis in Section 4.0. A summary tabulation of the
health and environmental effects of pollutants which can be emitted
by secondary sources is presented in Section 5.0.
Volume III contains Appendices A, B, C, D, and E
that list the companies which make up this industry and the raw
materials consumed and products produced by each. A bibliography
of references that also provided background information for this
study is included in Appendix F. Appendix G is a glossary of
commonly used terms.
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All of the process data presented in this volume
are expressed in metric units. English equivalents are generally-
given in parentheses. Conversions were carried out maintaining
levels of accuracy consistent with the original source of the
data.
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2.0
INDUSTRY OVERVIEW
The secondary nonferrous metal industry is made up
of 334 companies. These companies are listed in the Company
Directory (Volume III - Appendix A). The locations of these
companies are illustrated in Figure 2.0-1. This Company/Location
Map for the industry shows that the greatest concentration of
companies in this industry is in the New York City area. The
other five areas having high industry population densities are
the Cleveland, Chicago, Detroit, Philadelphia and Los Angeles
locales. The major reason for this is the high concentrations
of scrap producers and markets for products.
all segments as reported in the 1972 Census of Manufacturers was
nearly 2.1 billion dollars (US-276). It is estimated that the
total employment for the industry is approximately 17,SCO includ-
ing 13,200 production workers. These figures were based on a
total industry population of 381 establishments, a decrease from
the 403 establishments as indicated by the 1967 Census.
Appendices B and C of Volume III, respectively, it can be seen chat
many companies are engaged in the production of more than one
metal. To aid in characterizing the industry, the secondary ncr.-
ferrou£ metal industry is divided into eighteen segments listed
below.
The total value of shipments of secondary metals for
From the Company Product and Raw Material lists in
• Aluminum
• Indium
• Copper, Brass, and Bronze • Magnesium
- Cobalt
• Germanium
• Lead/Antimony
• Zinc
• Beryllium
• Cadmium
Hafnium
• Mercury
• Nickel
• Precious Metal
• Selenium
• Tin
• Titanium
• Zirconium
-3-
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These segments are described in detail in Section 3 of this report.
The total production and the company populations of
these segments are listed in Table 2.0-1. Because many companies
produce more than one metal, the company population figures do
not add up to 334. From this table, the four largest segments of
the industry are (a) Aluminum, (b) Copper, Brass, and Bronze, (c)
Lead/Antimony, and (d) Zinc, and these four segments account for 95
percent of the total industry production. From these production
figures, it follows that the total amounts of emissions and
effluents from these four major'segments will be greater than
those of the other fifteen segments. It should be emphasized,
however, that these smaller segments can emit very hazardous
pollutants and should be considered in characterizing the industry's
emission sources.
Total utility requirements for the secondary nonferrous
metal industry may also be estimated from 1971 data reported by
the Bureau of Census (US-074). Purchased fuels and electrical
energy amounted to 8.0 billion kilowatt-hours equivalent with
the total cost being 23.1 million dollars. Purchased electrical
energy represented 0.5 billion kilowatt-hours, costing 7.7
million dollars, while purchased fuels accounted for the remain-
ing energ\ demands A breakdown cf this latter category is
shown in Table 2.0-2, These utility usage data indicate that
the secondary nonferrous metal industry is mainly dependent on
electricity and natural gas as an energy source. Fuel oil and
ccal are secondary. The high demands for natural gas could
indicate that the future of the secondary nonferrous metal
industry will be impacted by the decrease in natural gas supplies
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Table 2.0-1. POPULATION AND PRODUCTION OF SEGMENTS
WITHIN THE SECONDARY NONFERROUS METAL
INDUSTRY
Population
Production
Number of companies
Metric tons
Segment
(1975)
Aluminum
131
816,000
Copper, Brass, and Bronze
108
313,000
Lead/Antimony
130
520,000
3 xnc
61
86,000
Beryllium
8
91
Cadmium
9
noa
Cobalt
14
120
Germanium
4
3. 6b
Hafnium
4
c
Indium
2
c
Magnesium
15
18,000
Mercury
16
407
Nickel
36
53,000
Precious Metals
53
1,324
Selenium
4
9d
Tin
57
13,000
Titanium
18
7,600
Zirconium
7
c
Source: Appendices D and E (Volume III), US-357
Estimated based on 5% of total (primary ar.i secondary-) cadmi t.
b Year of data not reported
Not reported
Includes cnly secondary seie-ium procuced from old scrap
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Table 2.0-2. QUANTITIES AND COSTS OF FUELS PURCHASED
BY THE SECONDARY NONFERROUS METAL INDUSTRY
IN 1973
Fuel
Quantity
Cost, Million $
Distillate fuel oil
Residual fuel oil
Natural gas
Coal
Coke and breeze
Other fuels
Fuels not specified by kind
Total:
434,300 barrels
145,100 barrels
14.0 x 10s cubic feet
3000 short tons
(not reported)
7.5 x 108 kW-hr
equivalents
2.0
0.6
7.7
(<$50,000)
1.3
1.4
2.5
15.5
Source: US-074
The industry currently is experiencing an upward growth
trend (1 to 67„ per year) with respect to production and particular
industry segment. This can be expected to continue as interest
in energy and raw material conservation continues. A second
observation of industry trends forecasts a continuing decline in
the number of companies as a result of consolidation, pollution
control regulations, and technical obsolescence. In addition,
the scrap producing facilities currently not considered within
the secondary metal industry may intensify their efforts in
secondary processing because of increasing transportation costs,
efficiency expansion, or other incentives. Finally, a growing
availability of municipal solid waste processing systems involving
classification and various degrees of scrap pretreatment may con-
s ;itute an ?-"dicional «rp«.nsion of the industry ooundaries.
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3.0
SECONDARY NQNFERRQUS METAL INDUSTRY SUMMARIES
In this section of the report, industry segment des-
criptions and environmental impact analysis results for each of
the 18 secondary industry segments identified in Section 2.0 are
presented. The four major industry segments (aluminum; copper,
brass and bronze; lead/antimony; and zinc) are described in sub-
sections 3.1 through 3.4. The remaining 14 minor metal recovery
segments are discussed (in alphabetical order) in subsections 3.5
through 3.18.
The format which has been established for the presentation
of industry data in this section involves (for each segment):
1) a segment description,
2) a segment analysis, and
3) a segment environment impact summary
Each segment description provides a brief overview of the companies
comprising the segment, production data, raw materials, products
and growth trends. The segment analysis section of each document
contains a process flowsheet and a description of possible schemes
for the flow of materials through the segment. Each process
identified on the flowsheet is characterized with respect to its;
• function
• input materials
• operating parameters
• utilities
• waste streams
• EPA source classification code
The EPA Scurce Classification Code 'SCC) is defined as a rumerica-
.:iing to define point sources or orocesses that exit air p.ilutan.f
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In the environmental impact summary sections the major sources
of environmental threat in each segment are discussed. Applicable
control techniques for each emission source are also reported along
with any available information on specific applications of those
technologies in the industry.
.9.
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3,1 Secondary Aluminum Segment
3.1.1 Segment Description - Secondary Aluminum
The aluminum segment of the secondary nonferrous metals
industry recovers, processes, remelts, and refines aluminum-
bearing scrap to produce metallic aluminum and aluminum alloys.
Companies whose primary service is the collection, handling, and
transport of scrap to the secondary aluminum plants are not
considered under this definition.
This segment of the secondary nonferrous metals industry
was established in 1904. It experienced major growth in the 1920's
and again in the late 1940's and 1950's. While the total output
of secondary aluminum has continued to increase in recent years,
the number of companies in the population has decreased particularly
in the last decade because of industry consolidation and technical
obsolescence.
Total aluminum consumption (primary and secondary) as
measured by shipments of aluminum ingot and mill products, increased
21 percent in 1973 (ST-328), The growing demand for aluminum is
partially evidenced by the aluminum can recycling trend. Can
collections in the first half of 1975 more than doubled the rate
for the equivalent period in 1973 (CA-289). Both energy and
environmental issues are responsible for this stimulated interest
in recycling programs. The projected growth rate of this segment
is approximately 6 percent per year (US-357).
According to the 1972 Census of Manufacturers there are
52 companies whose primary product is secondary aluminum ingot and
6 companies primarily engaged in manufacturing secondary aluminum
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billets. The total number of workers employed in these two groups
of companies are 4000 and 300, respectively (US-276). However, 131
companies were identified in the Raw Material and Product/Company
Listings in Appendices D and E (Vol. III).
The total 1975 domestic production of secondary aluminum
was 816,000 metric tons (900,000 short tons), a decrease of nine
percent compared to the 1974 production. Producers of secondary
aluminum which are not considered to be a part of the secondary
metals industry are primary producers, fabricators, foundries, and
chemical producers.
Estimates of the number of secondary aluminum smelting
plants in the United States range from 35 to 85 (EN-158, NA-182).
Approximately 30 percent of the total production comes from the
two largest companies, and another 30 percent comes from the next
four largest establishments. It is obvious from these figures
that the majority of the secondary aluminum produced in this
country is accounted for by a small number of large plants.
Most secondary aluminum plants are located near heavily
industrialized areas in order to be close to scrap suppliers and
customers. Unlike primary aluminum producers, it is not essential
for these plants to have access to major supplies of electricity
and water. This industry is centered around Chicago and Cleveland
in the Midwest, Los Angeles on the West Coast, and New York and
Philadelphia in the East; there are no secondary aluminum smelters
in the Rocky Mountains (EN-158).
Raw Materials
Raw materials costs represent approximately 75% of the
total costs of a secondary aluminum plant. The major raw material
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is scrap aluminum which is purchased in competitive markets from
scrap metal dealers and industrial plants. About 5X of the raw
material cost is for alloying ingredients such as copper and silicon.
Other process materials include degassing and demagging agents,
fluxes and grain refining agents. These are specified more fully in
the process descriptions presented in Section 3.1.2.
Raw materials purchased by secondary aluminum smelters
include new and old scrap, sweated pig, and some primary aluminum.
In 1973 the total consumption of scrap amounted to nearly 670,000
metric tons (ST-328). Table 3.1-1 presents a breakdown of the
types of scrap consumed by secondary smelters. For comparison,
the total consumption by other users of scrap aluminum (primary
producers, foundries, fabricators, and chemical plants) is also
shown.
Thirty distinct classifications for aluminum scrap have
been established by the Aluminum Smelters Research Institute (ASRI),
(now the Aluminum Recycling Association) based upon the copper,
silicon, zinc, and iron content of the scrap. Magnesium is not
specified since this more active contaminant can be removed with
relative ease during processing. These scrap classifications are
presented in Table 3.1-2.
New scrap results from semifabricating and fabricating
operations while old scrap refers to products of obsolescence.
Terms used to categorize new scrap are home (sometimes called
revert or runaround) and prompt industrial scrap. Home scrap is
recycled within the generating facility and thus does not enter
the commercial scrap market. Prompt industrial scrap, on the
other hand, is generated at facilities unequipped for recycling
and is often sold to the secondary aluminum industry.
-12-
-------
Table 3.1-1. U. S. COSSHKITIOtf OF ALUMINUM SCRAr AS3
SWEATED PIC IN 1973'*
Conn utsfi t iv*n,
at' connuater and type of xcrap metric ton
Secondary smclter^:^
New scrap:
Solids:
Sf^r^ated low copper (Cu aaxiaie, O.iZ) 136,909
Segregated high copper —————•— 8,730
Mixed low copper (Cu maximum, O.i*) —— 88,200
Hi^h sine (7000 series tvpc) —————— 6,073
Mixed clip* — — 74,122
Borings and turnings:
Lew copper
-------
Table 3.1-2.
A.S.R.I. ALUMINUM SCRAP CLASSIFICATIONS
1 NlwnJflf ALUMINUM CURINGS: She* constat of
«*•. clean. iheet aorf/or tfominum
tbeet Cuttuup, I'H from oil. treat*, foil md my other
Mmanca wd (torn punching! lm tKin on* hall
inch m iu«
2 NEW runt ALUMINUM mm AND CAftLE: SheM
coniitf ul Ptw, tlrni, uiuHoyfil aluDiifluni witi a* ciMt
fiee from hw w«e, wire kini. topini, won, kitulatron
and a««y ©the* lonifn aubstence.
3 OLO PU»E ALUMINUM WIRE AND CABLE: Shall
«w«H of ohJ, unitloYiditumwww or cilMi tofflitn
tn§ not o»« 1 f»er ««f (ih ©«**» or tfwt md |im bom
f»t* wire. wire Rffin, copper. Hon, Hmlition and any
ol*>tr lo eiuminum
tliiHUflgt of OfM Mcified ikimirHHii alloy only, f»e*
from haw w«t. wire screen, tail, tM iloiti. iliwNu
«*<*>, rful. oil. ftaM «nd any other ionim
auMiarxa. md from rH«*h(«|i Ifii ihm onehitt Inch
In tut
9. MIXED NEW ALUMINUM ALLOY CUPPINGS: Shall
conaitt of new. (Itmi, imtomd aluminum cl Of ««H| aHoyt, ANN) of wIikI) iM
• tne«»m.«m of «0% ramwi, 15* ti«f. .30* tw,
end 2 80% n^mqntrtHttn, and »hi« tie (in from ««i
coninnin| alloys. Kaw wdi, wmi «3»tn, iinnliii tiril,
Otl, great* »rt*W«i any oihtr foreign Mhi»ac*,
md (hall be h«i from punehmfi N>s then mx bUl inch
in tu»
f. SEGflEOAfEO OIO ALUMlNtIM ALLOY SHEET;
Shetl (OW4I of rlfft, uocoeted. old gfumintHR aheeI ol
on* *iectl«d alloy only, Iim hem wrecked airplene
•heel, heir mri, wki Kiwn. foil, tiaMaii attal. hon,
.dirt, o«l. gteete and any aiNt fofriyn aititimta
• MINED OLD ALLOY SHEET Shalt coniist of clean,
MBtoainl, eld afloy tfiNt eh«*«mu»n ol two or mon
a%, dean,
untnaittl aluminum castings. fot|fcifi and estnHvmt of
mm specified alloy only and Hr ba bM from vmanga.
nawlftt Mtd. tine, boo. «M«t. oH. ytaw and any other
loiiign sobtlance#
11. MIXED NEW ALUMINIUM FOHGINGS ANOEXTRU
SlOMS. Sh»M cOfiuM of cbaa. mm, awnalwl akwtlwiw
forgwtgs and eatruamns of two or met* eltoyt. none of
which iti»W I hi attoyi contesting tine In iicmi of .21%
|**h it tnM. lia .30% and/or maynaiwim ha
inttuel 2 BQ%. Shallriveliilira hoan sewings, stamiese
iiwlj ttnCj non. dirt. o»i. yt-itr and any ©the* lornign
lubillACt.
II. MIXED NEW ALUMINUM CASTINGS: Shalltoatsrsl of
claan. ww. uncoriftl afurnlntmi cattirwgt of «wa or morg
a'joifl. nooa of fvhkh_theM meted 3% >»nc, .W% ita,
mW« «t>iywtww m t«w« of ? Wit. Shall ba fcia of
tawinfl, HriwIeH fl«l. Moa^dirt. ail, ytaw. and any
Other fmeign Hrf»ia(Kti
13 ALUMINUM AUIO CASTINGS Shall cwu.it of *N
claan auiomofaili alufflinum tatllafi of sufficient aire to
ba readily Nfaitfifmi ml loUI'M from won,d*rt,b**t«.
balihill buthinfi, liratt ImrfiMy hid any «iN( faaifi
aWftrtati. Otl and yaata ao| to aacavd 7%.
11 ALUMINUM AIRPLANE CASTINGS: ShaM eonaiif of
clean alnnwiw»a catling ham and to lit Ira*
from iron, dwi, ImM, buiMnfS. Nait tMtthinje
and any oih«r foiatyn Oil and ftaata ratal to
a»e«ari 7%
IS MIXED ALUMINUM CASTINGS Shall comilt of all
clean ahMtttrtym tatiirfi Mwth may m may no* contain
auto and atrgrfana cawngi.lM no faqprm. and ts ba ftao
from tea, dirt. i»ait, iMfdMI and any other foreign
materurit o#l and ytaia not to rnunl 3%.
1t. ALUMINUM PISTONS:
Mclean aluminum pis ions. s»ioif conwat of
clean aluminum (NiMmt to be fc«a from niuta.
buihlnflt, duafti. nom rmfS and any othat foratfk
mawialt. Oil and yr.iM not *o airctd 7%.
fbl Al UMINUM PIS TONS Wl Til 51 flU TS: Shall comka
of clean whoN alvramum pHtwl with «|. m to ba
fiN ftom tw^iinfi, iHaftt, trot* tanyt at«c ta-y other
fofeifn nuitriali CM and yeata not fa eacoad 1%.
k! mONY ALUMINUM PISTONS: ShouM banMaa
rccowaty t>aui, or Ivy ipacM aiianynMHli im|tneMi wrtli iwithawf
». SiGflCOATCD ALUMINUM BO*IINGS AND TUMN
INGS S*»»* camtl of <*aen. ttWMiorfrd ahnum
hortnqa and Mnaifi of one k«kiIm>I tHny only end
•ulnrct to dnkitlKHji lor fines tn ncm of 1% itMough
• 30 medt acra«n anrf del. free aron, oil. m)
eH ether foreifo maftmh mob m
t«tw of 10% andMot any free maywuum or H»«d iutninyi of two or mo** aKoyt lAd iulijM to «le
ductrom <«ir ftrtee «n nreti of 3% through a ?0 mnh
tow a«J dkt, free iron, oil. «*mi material* Material contawinif non In «•<.**« of
10% andfor any free maunetMrm or itimlru «wl or
tonttiwiff htfMy Bwmit>le tutiinf rgntpownli. will
net ccmwittite pood de*Mery. TooracJ .ftamjta aiioutd be
taU cm Itawt of defmite tttaahnum imc, tin a<>d nvay
netkitn content
23. SWEATED ALUMINUM Shalt cootiit of afummum
•crap vwhictt h*t been a»»ratrd or meftad mto a form or
dtape such at an anfot, pr% or aM» for conwenHrnce m
tf«i|)|M«|; to be free from (Ofiotert. dro««aa or my
fo*e>fn rmitftali Shnwtd be auM aubiect to temple or
enalytrt.
24. ALUMINUM GfllNOtNGS Should be aoM on recovery
bain, or by apet ial ¦rtaofwrnenli with |twrchate«
». Al UMfNUM OHOf»Sf 5. SPA T TE US. SPILL INGS,
SKIMMINGS ANII SWEEPINGS. Should be aoM «a
¦ocowtry liMit. or by ttteciaf avtOftnenit w«h p^r-
thawr.
2C ALUMINUM HAW WtllE: Should be aoM by ^ectri
•tD^tntnll witft purchaser.
21. ALUMINUM WINE SCREEN SlMMdbe aohf by ivmcmI
err any menu with pwrdtMar.
2ft. COATED ALUMINUM IPAINTEO OR PLASTIC
COAICpT 1TC.I: Should be »ld by" *Kii eran#
menta «Mih purchetee. SeeNty. awnmge. and «enet«an
blandt dtnuM each be packaged aepereiely
2>- C¥ m'a^
manta with the purchaser, and iKmiU aachhipKlapd
•aparatafy.
30 JIIMS NOT COVERED SPtClllCAU YJY A^OVE
ClA'iSlHCA TIONS Arty new Hem ^•ch *|>t>«ar
and whach « not wwad apocaficalty by diowr
-------
New clippings, forgings, and other solids are purchased
from the aircraft industry, fabricators, and industry and govern-
ment manufacturing plants. Borings and turnings originate mainly
from the machining of castings, rods, and forgings by the aircraft
and automobile industries. Residues from melting operations at
primary production plants, secondary smelting operations, casting
plants, and other foundries include dross, skimmings, and slag.
Old scrap enters the market through scrap collectors
and dealers who collect, sort, and sometimes physically process the
scrap materials before delivering them to the secondary smelters.
Old scrap includes such items as automobile parts, household items,
and dismantled airplanes. High iron aluminum scrap is often con-
sidered a distinct scrap because it requires special pretreatment.
Sweated pig refers to scrap which has been treated in a pyrometal-
lurgical process to separate aluminum from higher melting constituents,
such as iron. Although sweating is considered to be a secondary
aluminum industry process, in some cases it is carried out by the
scrap dealer.
Products
Listed below are the chief products of the secondary
aluminum segment:
• Specification alloy ingots
• Billets
• Notched bars
• Shot
• Hot metal
• Hardeners
• Fines
-15-
-------
The most important cf these products are specification
alloy ingots which are generally cast in pigs (15 to 50 pounds)
or sows (500 to 1000 pounds), One-thousand-pound billet logs of
secondary aluminum for use in the extrusion industry are also cast.
Four standard grades of deoxidant for use in the iron and steel
industry are manufactured. These may be in the form of notched
bars or shot. Other products include hot metal, hardeners, and
fines.
Approximately ninety percent of the products from the
secondary aluminum industry are sold' to foundries (EN-158) . A
breakdown of the 1973 production of secondary aluminum alloys by
independent smelters is shown in Table 3.1-3.
3.1.2 Segment Analysis - Secondary Aluminum
The aluminum segment of the secondary nonferrous metals
industry is involved with the cleaning, melting, refining, and
pouring of scrap aluminum) An industry flowsheet showing the
processes used to convert scrap aluminum to secondary aluminum
products, 90 percent of which are sold to the foundry industry,
is presented in Figure 3.1-1. Because of variations in quality of
scrap received, product line specifications, equipment design, and
operating size, a general flowsheet is presented to show the possible
operations carried out at aluminum plants. ("Based on the industry
definition used in the present study, production of secondary
aluminum involves two general classes of operations: (1) scrap pre-
treatment and (2) smelting/refining
|Scrap pretreatment involves receiving, sorting, and
processing scrap to remove contaminants and to physically prepare
the material for smelting. Processes based on mechanical, pyro-
metallurgical, and hydrometallurgical techniques are used. Those
actually employed at a specific facility are selected on the basis
of the type of scrap processed.']
-16-
-------
Table 3.1-3. PRODUCTION OF SECONDARY ALUMINUM
ALLOYS BY INDEPENDENT SMELTERS IN 1973
Production8'*3
Alloy Metric tons Short tons
Pure aluminum (A1 minimum, 97.0%)—— — 109,769 121,020
Aluminum-silicon:
95/5 Al-Si, 356, etc. (Cu maximum, 0.6%)— 17,759 19,579
13% Si, 360, etc. (Cu maximum, 0.6%)— 51,609 56,899
Aluminum-silicon (Cu 0.6% to 2%)—— 3,611 3,981
No. 12 and variations— — — 9,439 10,407
Aluminum-copper (Si maximum 1.5%)— ——— 4,200 4,630
No. 319 and variations — — 56,550 62,347
Nos. 122 and 138 — 48 53
380 and variations 367,878 405,585
Aluminum-silicon-copper-nickel—— — 4,238 4,672
Deoxidizing and other destructive uses:
Grades-1 and 2 21,389 23,580
Grades 3 and 4 5,887 6,491
Aluminum-base "hardeners— — — 6,667 7,351
Aluminum-magnesium 3,198 3,526
Aluminum-zinc — — — 10,128 11,166
Miscellaneous— ¦ 18,874 20,809
Total 691,244 762,096
£
Gross weight, including copper, silicon, and other alloying elements.
Secondary smelters used 14,800 and 31,600 metric tons of primary aluminum
in 1972 and 1973, respectively, in producing secondary aluminum-based alloys.
^No allowance was made for consumption or receipts by producing plants.
Source: ST-328
-17-
-------
PRETREATMENT
SMELTING / REFINING
I \
00
1
bull
INSPECTION UNO
SCftJMP m
/raiiRCAtto\
H ALUMINUM I ^
V 8CRW J
1FLU1
rcmomm
lir
il
i.i-ii
RCV(MftE#tAV OR V
ICHLOfllHfl
SMtUMOmCFMNNG
KawM rfW
| y-rtDUWKl^
t.nt
KyMKBMOflt
IFtUOWWEt
SMCtVINQmfFlNMQ
r i
F1MEL
I.III
cmieste
IMILTilSmiFWWO
flUI rftCCTWCIT'
|Hlli |1
l.l-u
fttOUCflON
•MCLTlNOmtfMltMl
/ AttO* \
"*1 MOOTS I
/ MOfCHtO \
\zJ
LCOCNO
~ NOCIII
o
MMKIII wwei
FIGURE 3.1-1 PROCESS FLOW DIAGRAM FOR THE ALUMINUM SEGMENT OF THE SECONDARY NONFERROUS METAL INOUSTRY
-------
( The smelting/refining operation generally involves the
following steps:
* charging •• demagging
• melting • degassing
« fluxing * skimming
• alloying • pouring
* mixing /
All the above steps may be involved in each process,
with process distinctions being based mainly on furnace type
and emission characteristics. As with scrap pretreatment, however,
not all of these steps are necessarily incorporated into the
operations carried out at a particular plant. Also, some steps
may be combined or reordered, depending on furnace design, scrap
quality, process inputs, and product specifications.
Individual process descriptions for each scrap pre-
treatment and smelting/refining process follow this general
discussion. Information on utility requirements and operating
parameters were not available or were very incomplete in many
instances. Another area in which many data were unclear or incomplete
was the waste streams characterization area. Particulate emission
factors have been defined for reverberatory and crucible smelt-
ing/refining processes, chlorinating stations, and sweating
operations; however, neither particulate matter nor gaseous
emissions (specifically, hydrocarbons and gas phase inorganics)
have been adequately characterized with respect to their compositions.
Scrap quality variations (types and relative amounts of feed
impurities) can complicate the emission source characterization
problem significantly.
-19-
-------
SECONDARY ALUMINUM
PROCESS NO. 3.1-1
Inspection and Sorting
Function - The purchased aluminum scrap undergoes
inspection upon delivery. Clean scrap requiring no pretreatment
is transported to storage or is charged directly into the smelting
furnace. The bulk of the scrap, however, must be manually sorted
as it passes along a steel belt conveyor. Free iron, stainless
steel, zinc, brass, and over-sized materials are removed. If
the scrap has not yet been sorted according to physical form, the
following separations may also be made;
• Old castings and sheet
• Bulky sheet, clippings, and castings
• New clippings and forgings
• High-iron castings and sheet
• Aluminum cable
* Insulated cable
* Borings and turnings
* Skimmings, drosses, and slags
* Heavy metallic skim chunks
* Foil contaminated with paper, gutta-percha, or
insulation
-20-
-------
The sorted scrap then goes to appropriate scrap treat-
ing processes. If the scrap is already clean or if pretreating
facilities are not available, it may be charged directly to the
staeltinp furnace.
Input Materials - Aluminum scrap and contaminants.
Operating Parameters - Not available.
Utilities - Power to operate conveyors.
Waste Streams - Free iron, stainless steel, zinc, brass,
and over-sized scrap.
EPA Source Classification Code - None
-21-
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SECONDARY ALUMINUM
PROCESS NO. 3.1-2
Crushing/Screening
Function - Sorted scrap is conveyed to a ring crusher
or hammer mill where the material is shredded and crushed, and
the iron is torn away from the aluminum. The crushed material
is passed over vibrating screens to remove dirt and fines.
Tramp iron is removed by magnetic drums and/or belt separators.
The clean aluminum then falls directly into tote boxes.
Input Materials - Old scrap, especially castings and
sheet, contaminated with iron.
Operating Parameters - Not available.
Utilities - Power to drive equipment (conveyors, ring
crusher or hammer mill, vibrating screens, magnetic separators).
Waste Streams -
r
Minor amounts of metallic and non-metallic dust are
produced in this step)
• The quantity of solid waste (mostly tramp iron) is
expected to be low since the majority of the iron
should have been removed in the sorting process.
EPA Source Classification Code - None
-22-
-------
SECONDARY ALUMINUM
PROCESS NO. 3.1-3
Baling Process
^Function - Specially designed baling equipment is used
to compact bulky aluminum scrap. The bales produced are generally
1x2 meter (3x6 foot).
/'
Input Materials - Scrap sheet, castings, and clippings.
Operating Parameters - Not available
Utilities - Electricity required to drive baling equipment,
Waste Streams -
f
Particulate emissions consisting primarily of dirt and
alumina dust resulting from aluminum oxidation,
./
EPA Source Classification Code - None
-23-
-------
SECONDARY ALUMINUM
PROCESS NO, 3.1-4
Shredding/Class ifying
Function - {Pure aluminum cable with steel reinforce-
ment or insulation is Nrut by alligator type shears» then granulated
or further reduced in hammer mills to separate the iron core and the
plastic coating from the aluminum. Magnetic processing accomplishes
iron removal, and air classification separates the insulation.j
Input Materials - Aluminum cable with steel reinforce-
ment and/or neoprene or plastic insulation.
Operating Parameters - Not available.
Utilities - Energy requirements are those needed to drive
the equipment.
' Waste Streams -
* Minor air emissions (principally dust) are produced in
this process.
• Significant solid wastes are generated. The scrap
iron can be recycled. The plastic insulation is
generally disposed of in landfills.
EPA Source Classification Code - None
-24-
-------
SECONDARY ALUMINUM
PROCESS NO. 3.1-5
Burning/Drying
r
Function - In most cases, borings and turnings are pre-
treated in order to remove cutting oils, greases, moisture, and
free iron. The processing steps involved are (a) crushing in hammer
mills or ring crushers, (b) volatilizing the moisture and organics
in a gas- or oil-fired rotary dryer, (c) screening the dried chips
to remove aluminum fines, (d) magnetically treating the remainder
for iron removal, and (e) storing the clean dried borings in tote
boxes.
Input Materials -Borings, turnings, and other contami-
nated scrap.
. Utilities - Gas or fuel oil is required to fire the
rotary dryer, and additional power is needed to drive the other
equipment involved such as afterburners, motors, etc.
Operating Parameters - Not available.
Waste Streams
•/ Atmospheric emissions constitute a significant air
I pollution problem. Afterburners are generally used
to convert volatilized hydrocarbons to CO2 and K20.
Other gases potentially present, depending on the
composition of the organic contaminants, include
chlorides, fluorides, and sulfur oxides A Since fuel com-
bustion products are also emitted, oil 'firing produces
higher emissions than natural gas firing.
-25-
-------
; Oxidized aluminum fines blown out of the dryer by the
combustion gases constitute a source of particulate
emissions.)
•i Wet scrubbers are now used in some facilities to control
these emissions in place of afterburners. ^ This control
measure may result in a significant aqueous waste stream.
• The solid waste stream is chiefly composed of tramp iron
removed during the magnetic processing step.
EPA Source Classification Code - None
26-
-------
SECONDARY ALUMINUM
PROCESS NO. 3.1-6
Hot Dross Processing
'Function - Aluminum can be recovered from the hot dross
discharged from the refining furnace by batch fluxing with a salt-
cryolite mixture. This process is carried out in a mechanically
rotated, refractory lined barrel. The metal is tapped periodically
through a hole in the base of the barrel.^
Input Materials - Hot dross from smelting/refining opera-
tions and salt-cryolite flux.
Operating Parameters - Not available.
Utilities - Energy required to operate equipment.
Waste Streams -
•^Mechanically generated dust from the rotating barrel
constitutes the main air emission. Some fumes are also
produced as a result of the fluxing reactions. Both
of these problems can be controlled by enclosing the
barrel in a hood system and ducting the stream to a
baghouse^j No afterburner is required.
• Dry dross remaining in the barrel and baghouse dust
are the major solid wastes produced.
EPA Source Classification Code - None
-27-
-------
SECONDARY ALUMINUM
PROCESS NO. 3.1-7
Dry Milling
Function - In the dry milling process, (jcold aluminum-
laden dross and other residues are processed by milling, screen-
ing, and concentrating to obtain a product containing a minimum
. aluminum content of 60-707*. Ball mills, rod mills, or hammer mills
can be used to reduce the oxides and nonmetallics to fine powders.
Separation of dirt and other non-recoverables from the metal is
achieved by screening, air classification, and/or magnetic separa-
tion/ -
Input Materials - Residues (particularly low-aluminum
residues), drosses, skimmings, and slags.
Operating Parameters - Not available.
¦Utilities - Power required to drive the milling equipment.
Waste Streams -
• j^Large amounts of dust are generated as a result of the
'crushing, milling, screening, air classification and
materials transfer steps^) These emissions can be con-
tained by using hoods vented to baghouses. Wet dust
collection is used at a few facilities.
-28-
-------
• Aqueous effluents are generated when wet dust collectors
are used. The aqueous waste stream will contain sus-
pended solids such as aluminum oxide and hydrated alumina,
• and soluble chlorides. Milling drosses may also generate
ammonia when hydrolyzed by water. Slag processing generally
leads to higher levels of soluble potassium, sodium chloride,
and fluoride salts than the processing of drosses or
skimmings.
• Solid wastes consisting of alumina dust, dirt and iron
containing residues are generally disposed of on-site.
Attempts are being made to develop a market for this
waste because of its high alumina content.
EPA Source Classification Code - None
-29-
-------
SECONDARY ALUMINUM
PROCESS NO. 3.1-8
Wet llilling
f
Function -(Leaching involves (a) wet milling, (b) screening,
(c) drying, and (d) magnetic separation to remove fluxing salts and
other nonrecoverables from drosses, skimmings, and slags. First,
the raw material is fed into a long rotating drum or an attrition
or ball mill where soluble contaminants are leached out. The
washed material is then screened to remove fines and dissolved
salts, dried, and passed through a magnetic separator to remove
ferrous materials. The nomnagnetics are then stored or charged
directly to the smelting furnace.)
Input Materials - Input materials are the residues from
various smelting/refining operations such as slags, drosses, and
skimmings. A chemical analysis of a slag from a rotary-type
furnace is given below. In general, slags contain higher levels
of chlorides and fluorides than drosses or skimmings, while drosses
often contain aluminum nitride.
Table 3.1-4. CHEMICAL ANALYSIS OF A TYPICAL
ROTARY ALUMINUM FURNACE SLAG
Constituent Composition, percent
Aluminum 5-15
Aluminum oxide 25-35
Sodium chloride 25-33
Potassium chloride 25-33
Other 3_7
(Source: CA-307)
-30-
-------
Process water is also required. Of eight plants surveyed,
only two reported that they recycled water in their residue
treatment processes (EH-158). Quantities of wastewater generated
are discussed below.
Operating Parameters - Not available.
Utilities - Electrical energy is required for driving
the equipment and drying the screened material.
Waste Streams -
• There are no significant sources of atmospheric emissions
from this process with the possible exception of the
drying step where ammonia may be emitted. No specific
information was available on this topic.
* .Significant quantities of wastewater are generated by
this process. According to one survey, the wastewater
volumes generated in wet milling of residues ranged from
16,700 to 218,000 liters per metric ton of aluminum
recovered (EN-158). These effluents are typically very
saline, with high levels of suspended solids (aluminum
and alumina fines). Suspended solids levels of up to
30 wt. percent have been reported. Chemical analyses
(loadings and/or concentrations) of mi11ins wastewaters
from four different plants are presented in Table 3.1-5.
The differences which are observed are accounted for by
variations in residue and makeup water quality (e.g.,
fume scrubbing liquor, pond recycle liquor, or fresh
water. In all of the eight plants surveyed which use
-31-
-------
wet milling processes, the wastewater is sent to a
settling pond and, in several cases, chemically treated
before discharge.
• Solid wastes include the undersized materials from the
screening step and the settled wastewater solids. These
are generally disposed of in landfills.
EPA Source Classification Code - None
-32-
-------
l ED 16
3.1-5. T
YPICAL ANALY
5ES Oi SETTLED KASTEWA
TERS FROM
ALU!-'
:i>"UM RESIDUE
LEACHING OPERATIONS
Plants
1 a
-> b
3 c
u
£
Parameter (
wwo lag
Cone.
Cone. loading
Cone.
Loscir.g
ka/MT Al)
(mss/X)
(me'i) (kg/XT) e
(ms./l)
(kg/MT) «
Alkalinity
6.47
314
586 102
500
-7.5 f
COD
0.97
2,045
29
0.17
Total solids
24,264 5,144
17,800
326
Total dissolved
solids
13.51
12,920
17,400
324
Total suspended
solids
0.121
4,961
15 1.5
159
-5.6
Sulfate
1,100
47 1.5
151
1.8
Chloride
0.319
6,492
15,465 3,264
6,903
150
Cyanide
0.04
0.05
0
Fluoride
0.129
2.9
8.7 1.81
16.5
0.38
Asmonia
0.33
0.75
350 73
0.30
-0.03
Aluminum
0.002
0.3
16.4 3.5
28
-1.49
Calcium
58.8
23 -7.4
48
0.17
Copper
<0.001
0.174
0.070 0.008
0.137
0.003
Magnesium
32.5
6 3.9
76
1.39
Nickel
1.2
0.240 0.009
0.20
0
Sodium
2,560
11,600 2,528
3,103
46.2
Potassium
1,087
6,470 1,407
4,802
102
Zinc
0
0.015
0.10 0
0.198
-9.1
Cadmium
0.05
0.002 0
0.005
-0.001
Lead
0.20
0.020 0.004
0.028
-0.001
Manganese
0.16
0.045 0.002
0.060
0
Chlorine residue
—
—
—
Oils ana grease
0.053
55.4
0 0
0.5
0
Phenols (ppb) '
--
--
0.03
0
pH
8.68
8.3
9.09
9.2
Nitrates
0.032
a Calculated from U. S. Corps, of Engineers, concentration data not given.
b From residue milling solid waste washing, tonnage values of residue waste processed no:
available - loading cannot be calculated. Water flow is 151 ipm.
c Data from 7 month and 9 month average and verification data from state: metals verified
composite of 18 samples collected over a period of 6 days,
d Represents composite of 9 samples collected over 3 days. Milling waate stream is blended
with scrubber waste stream.
e loading calculicec &•>:
r ,,, . ... , Quantity cf w.ter used (1N
Lconc. effluent (mg/2) - cone, intake (ag/i)] x c.,er.slsy or A. recovered from reside i
f Negative values indicate that the process reduced the concentration of this parameter
and are derived from reported analytical values.
( ?."¦ u: -e : E:\-I58)
-33-
-------
SECONDARY ALUHIl'UM
PROCESS MO 3.1-9
Roasting
f
function -'In the roasting process, carbonaceous
materials associated with aluminum foil are charred-and then
separated from the metal product.'',
Input Materials - Aluminum foil backed with paper,
gutta-percha, or insulation.
Operating Parameters - Net available.
Utilities - Fuel for roasting and power required by
auxiliary equipment.
Waste Streams -
• Although no specific information was found, it is
expected that atmospheric emissions result from this
process.
r
I* Charred scrap materials constitute the major solid
waste stream generated by the roasting process. >
/
EPA Source Classification Code - None
-34-
-------
SECONDARY ALUMINUM
PROCESS NO. 3.1-10
Aluminum Sweating
f
Function -I Sweating is a pyrometallurgical process
which is used to recover aluminum from high iron content scrap.
Open-flame reverberatory furnaces with sloping hearths are generally
employed, although grate-type furnaces are also in use. Separation
is accomplished as aluminum and other low melting constituents melt
out ar»d trickle down the hearth, through a grate and into air-
cooled molds or collecting pots. The product is termed "sweated
pig". The higher melting materials including iron, brass, and
oxidation products formed during the sweating process are periodi-
cally removed from the furnace
Incut Materials - High-iron aluminum scrap, particularly
old sheet, castings, and dross,
'Operating Parameters - Operating temperatures range from
630-760°C (1250-14000F).
Utilities - Sweating furnaces are fired by either gas
or oil. Additional energy is required to pov.er auxi 1 iary equipment.
Waste Streams -
/^Atmospheric emissions are a function of the feed scrap
composition. Smoke may result from incomplete combustion
of organic contaminants (e.g., rubber, oil, and grease,
plastics, paint, cardboard, paper) which may be present.
-35-
-------
CORPORATION
^ Fumes can result from oxidation of magnesium and zinc
contaminants. Sweating of drosses ana skims containing
fluxes may create fumes^) Residual aluminum chloride
flux sublimes at 178eC (352°F) and is extremely hygro-
scopic; subsequent hydrolysis results in HC1 formation.
Chemical characterizations of atmospheric emissions were
not available; however, particulate emissions are known
to consist chiefly of aluminum trioxide. The particu-
late emission factor for an aluminum sweating furnaces is
7.25 kg/MT (14-5 lb/ton) of metal processed (EN-030).
For baghouse-controlled processes, the factor is
1.65 kg/MT (3.3 lb/ton) of metal processed (EN-03Q).
Particle size data from an aluminum sweating reverberatory
furnace with a capacity of 345 kg/hr (7 60 Ib/hr) are
given in Table 3.1-6.
Table 3.1-6. PARTICLE SIZE DATA - ALUMINUM SWEATING FURNACE EMISSIONS
Particle Dirrr-sr^r Cumulative height:
< ¦
1.79
10
4.8
2. 38
10.8
3.57
24.3
4. 76
37.3
7.10
55.6
8.90
65.8
10.10
70.2
11. 90
76.4
14.30
82.9
21.40
88.9
39. 30
95.5
71.40
99 . D
(Source: TV-069)
-36-
-------
Reduction of atmospheric emissions can be achieved by
(1) installation of adequate hooding systems to capture
emissions generated during residue removal and charg-
ing, (2) proper burner operation, and (3) removing
magnesium and combustible contaminants from the scra~ be
charging. An afterburner followed by a baghouse is
recommended to control emissions.
The major solid wastes stream from this process is an
ron-containing residue contaminated with aluminum and
other nonferrous metals such as zinc, magnesium, and lea
EPA Source Classification Code - 3-04-001-01
-37-
-------
SECONDARY ALUMINUM
process ::o. 3.1-11
Reverberatorv Smelting-Re fining with Chlorine Demagging
^Function - Reverberators furnaces are commonly used
to convert clean sorted scrap, sweated pigs, or in some.cases
untreated scrap to specification alloy ingots, shot, and hot
metal. The steps described below may be reordered or even
excluded from a particular smelter's operation, depending on
the type of scrap processed, product specifications, and facilities
available.
The scrap is charged to the furnace by some mechanical
means, octen through charging wells designed to permit intro-
duction of chips and light scrap below the surface of a previously
melted charge ("heel"). Batch processing is generally practiced
for alloy ingot production. Continuous feeding and pouring are
generally used to produce products having less restrictive speci-
fications. j
f Cover fluxes are used to prevent contact with and sub-
sequent oxidation of the melt by air. Solvent fluxes react with
nonmetallics such as residues from burned coatings and dirt to
form insolubles which float to the surface as cart of the slag.•
J
Alloying agents are charged through the forewe11 in
amounts determined by product specifications. Injection of
nitrogen er other inert gases can be used tc promote and to aid
in raising dissolved gases, typically hydrogen, and intermixed
solids to the surface.
-38-
-------
•Demagging reduces the magnesium content of the molten
charge from approximately 0.3 - 0.57e (typical scrap value) to
about 0.1% (typical product line alloys specification). When
demagging with chlorine gas, chlorine, injected under pressure
through carbon tubes or lances, reacts with magnesium and aluminum
as it bubbles to the surface. ¦ Recently, chlorination chambers have
been designed as an improved feature of reverberatory furnaces.
Other chlorinating agents, or fluxes, such as anhydrous aluminum
chloride or chlorinated organics are sometimes used. /
The melt is typically degassed with nitrogen, chlorine,
or nitrogen/chlorine mixtures. In some cases solid degassing
fluxes may be used. Other degassing techniques available include
vibration, high vacuum, and solidification with remelting. This
step is necessary to remove dissolved hydrogen, oxygen, and
moisture from the melt.
r
I In the skimming step, contaminated semisolid fluxes
(dross, slag, or skimmings) are ladled from the surface of the
melt and removed through the forewell. The melt is then precooled
before pouring Recording to one of the following methods:
• Alloy ingots, billets, and notched bars are poured
into mo1ds and cooled by direct or indirect water
cooling, water or mist/air sprays, or air cooling..
• Aluminum shot is produced by pouring molten aluminum
onto a vibrating feeder and quenching with water.
• Hot metal is obtained by pouring the aluminum into
heated crucibles having capacities ranging up to
6800 kg (15,000 lb.) .
-39-
-------
Input Materials - The input materials to this process
include treated or untreated scrap, sweated pigs, fluxes, alloy-
ing agents, chlorinating agents, and degassing agents. Commonly
used chemicals are:
Cover flux: sodium chloride
potassium chloride
calcium chloride
calcium fluoride
aluminum fluroide
common mixture : 47 .57= NaCl
47.5% KC1
5% cryolite
Solvent flux:
aluminum chloride
ammonium chloride
zinc chloride
cryolite
other fluorides
borax
Alloying
agents; copper
silicon
manganese
magnesium
zinc
-40-
-------
Mixing and/or degassing agents
nitrogen
chlorine
nitrogen/chlorine mixture (90:10%)
helium
argon
metallic chlorides (solid)
Chlorinating agents:
chlorine
anhydrous aluminum chloride
chlorinated organics
The quantity of cover flux added is a function of the
surface area of scrap. Generally the flux is 10-33% by weight of
the total material charged (flux plus scrap).
The theoretical demagging agent requirement is 3.5 kg
chlorine per kg Mg removed; however, in practice this may run as
high as 15 kg Ci/Kg Mg (or 5 to 6 150-lb chlorine cylinders/50 ton
furnace) (EN-158, LA-186).
Operating Parameters - Typical operating parameters are:
~ Furnace capacity: 15-90 tons
• Typical chlorination chamber dimensions: 1.2m x 3.0m
* Charging time: 4-75 hours (avg. 24)
* Length of heating cycle: variable
• Temperature (chlorination step): 760-820°C (1400-1500°F)
* Temperature (pouring): 732°C (13506F)
-41-
-------
Utilities - Reverberatory furnaces are directly fired
on either natural gas or fuel oil. Heat input per kilogram of
alloy may range from 1100-1400 kcal (2000-2500 Btu/lb). Additional
energy requirements are those needed to operate auxiliary equipment.
The total energy requirement for the entire remeltins
process for aluminum can recycling, including transportation and
delacquering, is 0.11 kWhr (or 1900 kcal), per kilogram of molten
metal (0.05 kWhr or 3420 Btu per lb) (AT-060).
Water usage in this process varies widely depending on
the extent to which water is used for ingot cooling. Reported
water usage for five plants (all using once through cooling water)
ranged from 250 to 11,500-liters per metric ton of metal cooled.
One plant reported that it used 60,000 liters per metric ton for
shot quenching. No data were available for plants which recycle
their cooling water (EN-158).
ftaste Streams -
•f Atmospheric emissions from this process in? stex> represent
i i - -
a significant fraction of the total particulate and gaseous
effluents generated in the secondary aluminum industry.
Typical furnace effluent gases vill contain combustion
products, chlorine, hydrogen chloride, metal chlorides
(e.g., zinc, magnesium, and aluminum), aluminum oxide,
and various metals and metal compounds depending on the
quality of scrap consumed^
The particulate emission factor for the reverberatory
smelting process, exclusive of the demagging step, is
2.15 kg/metric ton of metal processed (4.3 lb/short ton).
-42-
-------
Baghouses or electrostatic precipitators reduce this
factor to 0.65 kg/metric ton (1.3 .g/short ton) (EN-030).
Particulate control efficiencies of these devices can
be as high as 90+%, it has been estimated that approxi-
mately 60% of the reverberatory smelters in the secondary
aluminum industry employ some form of particulate
control device.
The uncontrolled particulate emission factor for the
chlorination step (a major potential pollution source),
is 500 kg/metric ton of chlorine used (1000 lb/short ton).
The controlled emission factor (baghouse) is 25 kg of
particulate per ton (50 lb/short ton) (EN-030).
The compositions of the atmospheric emissions from
various process steps vary widely depending on such
things as quality of scrap, fluxes used, operating
parameters, degassing and demagging agents, and furnace
•type. Air emissions from a typical reverberatory (chlorine)
smelting refining process include combustion products;
chlorine; hydrogen chloride; chlorides of aluminum,
zinc, and magnesium; aluminum oxide; and various metallic
species depending on scrap quality. Qualitative de-
scriptions of the air emissions resulting from each
processing step are summarized in the first two columns
of Table 3.1-7.
Application of air pollution control equipment to this
process in part depends on the furnace configuration. If
a charging well (forewell) or separate chlorinating station
is present,more efficient use can be made of gas cleaning
systems because this configuration generally allows
-43-
-------
Table 3.1-7. WASTE STREAMS FROM REVERBERATORY (CHLORINE) SMEI.T1 NC-RF.F1 N1NC PROCESS
Flu*t«C.
• 1 tojrl , ami
-LI** t»tt
I
4>
f
l|.l< M-.r
Tumi ami Mok* IrM
wiMlutlM aml/M ...
tie* af »rt*f r*ntHitiMKM*
Caawft: Nl( iimm,
4m, kyiiMfaa iblMil*.
Md «ilx«
fiiTum'Wti
*ia H*|«(
riti iA»* t
Particulate
timtllii '
*|th «(itwi
I* hJIm tklmlitt «ltl
•toet iMwm of ilwlwo
«M cBf a.imk
M4I(1tnr>,
r*rtlewlata Aimlim
cliloiIJS. iftaalRtaa riMitik.
iluiltuM niidf, aafnatitaa
rtloliJ*. WfMllMI {|tKtfl4«
MimiIm mI4(, («|(lw
cfclartito,
i«nNh» tl«K a*l(l( faltlliwt
NitilfM af k)4r»r*iMMi
•¦Hi IMUll* Iftwll If W|f|
lltwii t* (MtKt MlUfcl
««• allitAtt ^flNnl la ll«|
«¦«!•* *«frl*t Cfitnltl
fey ikmxt vara
immS t* MtlUI**
MWlUl tha» 1 MUMI with
¦Nl af tha M'tltU* <1,1
tlccaw. ft* f«M* wet* ckHKtM
Ml m mrall**, ^intfttlirlf
<*M K*t
ifcMt ••IlllMI •*« (Mllllii ta
• If ffllftlw CMHf«l
(altWr wMmtn, at
aalll Milt) at |ilwtt ilrti mm*
• *f* IdfltMlW «•«
MIm
1%* which laal*(tll-IM)
• aftfMMlaa I |>l«"l»
• 4l*act 4lidwr|t la mmnIcI|>*I mwi I h al.inta
• at ill "wIM Iik
«aMial wtlali Im Cli-».nr4 |mif«lii> (Ha
4l»rh»*ra
. with mm ract'llwc tf
. with IMtal tac|ll«i »
. «a*»«weawa (tcytl*.
Mfcharga I
• ta t»»f wlaa pwmi I
. with Maitallaailaa II
• with aallla t«aa««l If
Confatltiun
51 aft, akta*>l*ga. «« 4*o
9l«*%a kal|*f, aay»>-Ullr
tf* ahM taMKhlai, a»«t
ha (ttrMUill)) i«aB«ti
InHflllittloa a< Miirvatti.
mmf in<-r«|t*
4i«|><»*r4 i»| ta Ijn4lllla
rtw |kB»ratlal f«M
• MlHMl l
-------
separation of combustion gases from emissions from fluxing,
demagging and degassing. Furnace combustion gases and
charging emissions are generally vented directly to the
atmosphere. Fumes from the chlorinating station can
be captured by a submerged hood and ducted to a gas
cleaning system. Hazardous gaseous components and some
particulates can be removed by alkaline or aqueous
scrubbing, often followed by a particulate control device
such as a baghouse or electrostatic precipitator. Coated
baghouses are also used to some extent for halogenated
gas absorption. Efficiencies of various scrubbing systems
applied to demagging fumes are compared in Table 3.1-8,
and efficiencies of several particulate control devices
are shown in Table 3.1-9.
* Wastewater effluents from the Reverberatory Smelting-
Refining Process with chlorine demagging include metal
cooling water and fume scrubbing effluent. Quantities
of each, particularly cooling water, are extremely
variable from plant to plant and, in addition, water
usage in general is not well defined. For example,
reported water usage for ingot cooling at five plants
ranged from 250 to 11,500 liters per metric ton of
metal cooled (60-2760 gal/short ton) (EN-158). Quantities
discharged were not given. Wastewater flow from wet
scrubbing of chlorination fumes is approximately 95 to
190 liters per kg of Mg removed (11-23 gal/lb) (EN-158).
Compositions and disposal practices for both of these
wastewater effluents are summarized in Tables 3.1-7,
3.1-10, and 3.1-11.
-45-
-------
Table 3.1-8. SCRUBBER COLLECTION EFFICIENCIES FOR
EMISSIONS FROM SECONDARY ALUMINUM
REVERBERATORY SMELTERS WITH CHLORINE
DEMAGGING
Scrubber
collection efficiencies, %a
Slot scrubber
Packed-column scrubber
Contaminants
Water
107, caustic
solution
Water
10% caustic
solution
HC1
90 to 95
95 to 99
95 to 98
99 to 100
CU
30 to 50
50 to 60
75 to 85
90 to 95
Particulates
30 to 50
50 to 60
70 to 80
80 to 90
3. '
Collection efficiency depends raainly upon the L/G ratio, the
velocity of gas in the scrubber, and other aspects of the
scrubber design. These values are typical efficiencies obtained
by actual tests but do not reflect the entire ranfe of possible
results.
Source: DA-069
-46-
-------
Table 3.1-9. AVERAGE PARTICULATE COLLECTION EFFICIENCY OBTAINED
BY USING VARIOUS DEVICES ON EMISSIONS FROM SECONDARY ALUMINUM
REVERBERATORY SMELTERS WITH CHLORINE DEMAGGING
Type of device
Efficiency, 7„
Horizontal multipass wet cyclone
65
to
75
Single-pass wet dynamic collector
70
to
80
Packed-column water scrubber with
limestone packing
75
to
85
Ultrasonic agglomerator followed by
a multitube dry cyclone
85
to
98
Electrical precipitator
90
to
99
Source: Jenny, 1951, as cited in DA-069
-47-
-------
Table 3.1-10. CHARACTER OF COOLING WASTEWATER
FROM ALUMINUM REVERBERATOR? FURNACES WITH
CHLORINE DEMAGGING
Ptraaaecr
Plant I
Concentration Vac Lea4i.Bg
¦g/i g/KI product
Plane 2
Concentration mi loading
as/£ g/MI product
Plant 3
Concentration Hat Loading
ag/l g/KI product
Alkalinity
COD
focal aolids
Total dissolved
aolida
local suspended
solids
Sulfate
Chloride
Cyanide
Fluoride
*«iK»n11
Hierate
Alimlmm
Calciua
Copper
Magnesiun
Nickel
Sodiun
Zinc
TitHftl 1ITT
Lead
Manganese
Chlorine residue
Oils and graaac
Phenols (ppb)
pB
7.3
1106
1215
248
929
13.3
143
0.03
0.78
10.0?
2.26
0.133
1.15
0.03
3.59
0.61
0.015
0.46
0.10
0.02
1833
99.3
5.J
815
766
119
626
6.3
93.0
0.006
7.26
0.065
0.007
0.271
0.393
0.004
0.261
0.061
0
1240
0.043
5.5
237
244
1146
989
157
24
310
.004
2.3
1.7
18.4
0.026
4.05
0.26
733
0.013
0.01
0.10
0.30
259
m
6.4
138
545
465
80
7
174
.002
0.33
0.015
1.61
0.10
420
0.006
0.006
0.17
147
95
15
198
180
18
29
0.9
0,7
172
69
182
46
0.008
5 (?)
4.5 - 6.5
86
* Hater usage at Chi* plant it 39,700 Z/day (avg.) and metric tons poured is 58.5 MT/day.
Water flow is 30 gp» for 260 *in. per day (avg.) and 51 HT of meral are poured daily.
L Water us.ixe is 302,800 l/day and 21-30 MT of metal are poured daily.
d
{Cone effiucne - cone incake (mg/D) x liters/day -3 A,
Avg. amount of nwtai cooled, mcons/day * gram/mg " loading, gram/neon
Source: EN-158
-48-
-------
Table 3.1-11
CHARACTER OF UNTREATED WASTEWATER FROM
CHLORINATION FUME SCRUBBING
••rmcir
Hani C-7
Cone.,
ag/t
Loading,
grana/kg H|
Flint D-6
Cone..
¦g/J
loading,
crass/kg >4
COO
Total eolida
local diaaolvad
aollds
Total suspended
•olid*
Sulfas*
Chloride
Cyanide
Fluoride
Aiumlnua
Calcium
Coppar
Ma*tiseiu*
Nlckal
Sodiua
Fotaaaiua
Ziae
CadBiua
Laatl
Hanganaae
Chlorine r«Aduc
011a and grass*
Ph«nol« (ppb)
PH
123
2*10
1(85
223
11
4420
<0.02
0.24
472
0.12
0.25
*1.2
0.050
3.11
0.152
0.066
0.061
0.449
0.257
13. S
20.7
2.1
«>
12.1
301
194
22.3
0.51
446
0
-0.01
50.*
-0.215
0.02
3.(6
0.003
-0.007
0.091
0.006
0.004
0.049
0.027
0.5*0
-0.002
536
10,500
4(0
4(1
8,671
0.7
6.12
990
1.31
55.8
0.74
770
206
3.58
0.30
0.24
2.34
6.24
1.0
95.8
1156
83.0
(4.4
1560
-0.324
0.615
176
0.236
9.81
0.106
32.7
37.1
0.64
0.054
0.025
0.349
0.403
Avurttge of three eonposit* staples.
Average o: five coapeait* saatplas.
Loading calculated aas
{rone, affluent (Bg/u - Cone, intake (mm/l)ix Quantity of water a»«d (H
quantity of Kg removed (kg)
Sci5iicl*« nuahera Indicate that the procaas apparently reduced the concentration of this
parameter. and ate derived jreat the report* of analytical results as «hi ateve.
KS-1 58
-49-
-------
• The solid wastes generated in this process are: (1)
drosses and skimmings which are usually recycled
(Processes 3.1-6 through 3.1-8), (2) particulate control
residuals, typically disposed of by landfill, and
(3) sludge from wastewater treatment. Characteristics
of these emissions are summarized in Table 3.1-7.
EPA Source Classification Code -
3-04-001-03 Smelting - reverberatory furnace
3-04-001-04 Chlorinating station
-50-
-------
SECONDARY ALUMINUM
PROCESS NO. 3.1-12
Reverberatory Smelting-Refining with Fluorine Demagging
Function -/' This process is similar to the Reverberatory
SmeIting-Refining Process with chlorine demagging except that aluminum
fluoride rather than chlorine is employed in the demagging step. The
AIF3 reacts with magnesium to produce metallic aluminum and magnesium
fluoride, which then floats to the surface and is skimmed off *
Input Materials - The raw materials charged to this
process are treated or untreated scrap, fluxes, alloying agents,
aluminum fluoride, and nitrogen or other degassing agents.
The weight of aluminum fluoride required for magnesium
removal is approximately 4.3 kg/kg Mg (EN-158). In some cases as
much as one ton of A1F may be required when charging a 40- to 50-
ton furnace.
The types and amounts of other input materials are
described in Process No. 3.1-11.
Operating Parameters - Refer to Process No. 3.1-11.
Utilities - The utility requirements for this process
include:
• Natural gas or fuel oil
• Energy to drive auxiliary equipment
• Cooling water
-51-
-------
Refer to Process No. 3.1-11 for further information.
Waste Streams -
* The use of AIF3 rather than chlorine in the demagging
* step results in reduced atmospheric emissions. Fluorides
emitted as gaseous fluorides (hydrogen fluoride, aluminum
and magnesium fluoride vapors, and silicon tetrafluoride)
or as dusts require control to prevent significant
\ j
environmental impact ^ / Atmospheric emissions from other
process steps are similar to those emitted from
reverberatory (chlorine) smelting-refining I (Process No.
3.1-11).
Of the 14 secondary aluminum plants surveyed which use
AIF3 for demagging, 7 used fabric filters, 2 had wet
scrubbers, and 5 were uncontrolled (EN-158). Venturi
wet scrubbers are usually used for fluoride emission
control.
Aqueous waste streams result from metal cooling and
fume scrubbing. Cooling water effluents were discussed
under Process 3.1-11.
Fluoride-containing scrubbing liquors do not constitute
a significant wastewater stream. Neutralization effects
the precipitation of fluorides, which are generally
sparingly soluble compounds. This allows recirculation
of the supernatant to the scrubber. Recycled scrubber
liquor contains residual fluorides of magnesium, aluminum,
and possibly cryolite.
~ Settled solids from neutralization of fluoride scrubber
liquors constitute a solid waste stream. This sludge is
normally dewatered and disposed of as landfill.
-52-
-------
Other solid wastes from this process are air pollution
control residuals from dry collection systems and dross,
slag, or skimmings from the skimming step. These were
discussed under Process No. 3.1-11.
EPA Source Classification Code - 3-04-001-03
-53-
-------
SECONDARY ALUMINUM
PROCESS NO. 3.1-13
Crucible Sme11 ing-Refining
r
Function -! The crucible smeIting-refining process is
used to remelt small batches of aluminum scrap; this type of
furnace is generally limited to 500 kg (1000 lb) capacities or
less. The process steps are essentially the same as those of
as ladles for pouring. Larger ones are usually of the tilting
type, where metal is transferred to smaller capacity ladles
before pouring into molds.
with either gas or fuel oil. In general, efficiency of fuel
usage with this furnace type is extremely low, in some cases
5 percent or less (DA-069). Electricity is sometimes used as
a heat source.
Waste Streams - This process creates wastes similar
to the reverberatory processes; the quantities produced, however,
are much less due to the size of the operation.
Small crucibles are lifted out of the furnace and used
Input Materials - Refer to Process 3.1-11.
Operating Parameters - Not available
Utilities - Crucible furnaces are fired 'indirectly
EPA Source Classification Code - 3-04-001-02
-54-
-------
SECONDARY ALUMINUM
PROCESS NO. 3.1-14
Induction Smelting-Refining
° °
Function -((This process is designed to produce hardeners
by blending superpure aluminum and hardening agents in an electric
induction furnace. The process steps involved include (a) charging
scrap to the furnace, (b) melting, (c) adding and blending the
hardening agent, (d) skimming, (e) pouring, and (f) casting. The
hardened product is cast in the form of notched bars
Input Materials - Electrical conductor scrap (superpure
aluminum) and hardening agents (titanium, boron and/or chromium) are
the feeds to this process.
Operating Parameters - The capacities of induction
furnaces used for melting aluminum are much smaller than re-
verberatory furnaces. This furnace type offers higher efficiencies,
closer tetaperature control, less oxidation, and improved melt
homogeneity.
Utilities - Electricity requirements are those needed to
melt the scrap and to operate auxiliary equipment.
Waste Streams -
•
• Small quantities of atmospheric emissions containing
aluminum, alloying agents, and other metals are generated
in all process steps. Combustion products are not
present in emissions from induction furnaces.
-55-
-------
* The only potential source of aqueous waste from this
process is the furnace and metal cooling water.
* Drosses from the skimming step are the only solid
wastes,
* Further details of these waste effluents are presented
in Process 3.1-11.
EPA Source Classification Code - None
-56-
-------
3.1.3 Environmental Impact - Secondary Aluminum
The aluminum segment of the secondary nonferrous metal
industry is a source of fine particulate matter and gaseous
atmospheric emissions, wastewater, and solid wastes. These
emissions can represent significant health and environmental hazards
if not properly controlled.
The most serious air pollution problem associated with
this industry segment which occurs during sme11ing-refining is the
fuming produced during the demagging step. These fumes may consist
of halogenated volatiles and/or particulates, metallic species, and
combustion gases. Significant particulate and gaseous emissions can
also be generated during scrap pretreatment processes such as aluminum
sweating, dross processing, and burning/drying. Control measures are
available to reduce the most serious of these air emissions. Dry pro-
cesses (fabric filters) are usually employed for particulate control,
while wet scrubbing techniques or coated fabric filters are necessary
for gaseous halide removal. Alternate demagging processes which
minimize fuming are under development. Fugitive emissions are also
present due to material transfer and storage.
Chloride fume scrubbing liquors constitute a significant
wastewater problem, while fluoride liquors can be recycled after
neutralization and solids removal. Another wastewater effluent
is metal cooling water. This stream, which does not normally contain
significant quantities of hazardous components is typically dis-
charged to ponds, streams, or municipal sewer systems. Leaching
of dross and skimmings from the smelting-refining operation creates
considerable wastewater effluents containing high saline and sus-
pended solids levels. The best practicable control technologies
currently available for treating these four types of wastewater
are (EN-158):
-57-
-------
• Chloride fuse scrubbing effluents - pH adjustment
and settling
• Fluoride fume scrubbing liquors - pH adjustment,
settling; (total recycle usually possible)
• Metal cooling wastewater - air cooling or continuous
recycle with periodic removal, dewatering, and dis-
posal of sludge
• Dross wet milling - pH adjustment and settling with
some recycling to minimize discharge
Effluent limitations for chloride fume scrubber effluent and wet
dross milling discharges which must be met by existing sources by
1 July 1977 are presented in Tables 3.1-12 and 3.1-13.
Solid wastes from secondary aluminum production include
dross and skimmings from smelting/refining operations, air pollution
control residuals, wastewater neutralization sludge, and discarded
scrap contaminants from sorting and classifying and sweating pro-
cesses. Drosses can be recycled or disposed of with the other solid
waste streams,which typically wind up in landfills.
For 1974, the-total scrubber sludge and furnace slag
disposal from the Aluminum Segment was 101,100 and 245,000 MT,
respectively (EN-399). These solid wastes contain hazardous con-
stituents and represent a significant hazard to health and the
environment.
Several of the emissions identified in this section
constitute significant health and environmental hazards. These
effects are summarized in the Preliminary Pollutant Health and
Environmental Impact Table presented in Section 5. Table 3.1-14
illustrates the process, emissions, and control technology for
the Aluminum Segment.
-58-
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Table 3.1-12. EFFLUENT LIMITATIONS FOR TREATED FUME
SCRUBBER WASTEWATER GENERATED DURING CHLORINE DEMAGGING
TO BE ACHIEVED BY JULY 1, 1977, BASED ON THE BEST
PRACTICABLE CONTROL TECHNOLOGY CURRENTLY AVAILABLE
Effluent Characteristic Effluent Limitation8
(kg per 1000 kg Mg removed)
TSS
COD
pH
175
6.5
7.5-9.0
a Average of daily values for 30 consecutive days shall not
. exceed the limitation values.
Source: EN-158
-59-
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Table 3.1-13. EFFLUENT LIMITATIONS FOR TREATED
WASTEWATER FROM RESIDUE MILLING TO BE ACHIEVED BY JULY 1,
1977, BASED ON THE BEST PRACTICABLE CONTROL
TECHNOLOGY CURRENTLY AVAILABLE
Effluent Characteristic Effluent Limitations3
(kg per 1000 kg product)
TSS 1.5
Fluoride . 4
Ammonia (as N) .01
Aluminum 1.0
Copper .003
'COD 1.0
pH Within the range of 7.5 to 9.0
a Average of daily values for 30 consecutive days shall
not exceed limitation value.
Source: EN-158
-60-
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Table 3.1-14. PROCESS POLLUTANT AND CONTROL SUMMARY - ALUMINUM SEGMENT
Process & Pollution Control
Air Emissions
Aqueous Effluents
Solid Wastes
3.1-1 Inspection and Sorting
EPA SCC; None
None Reported
None Reported
Free iron, stainless steel,
zinc, brass and over-sized
scrap
Pollution Control
None Reported
None Reported
None Reported
3.1-2 Crushing/Screening
EPA SCC; None
Particulates
Low amounts of dust
Hone Reported
Tramp iron
Pollution Control
None Reported
None Reported
None Reported
3.1-3 Baling
EPA SCC: None
Particulates
Dirt and alumina dust
None Reported
None Reported
Pollution Control
None Reported
None Reported
None Reported
3.1-4 Shredding/Classifying
EPA SCC: None
Particulates
Low amounts of dust
and otlier particulate
matter
None Reported
Scrap iron and plastic
insulation
Pollution Control
None Reported
None Reported
Recycling or landfill
3.1-5 Burning/Drying
EPA SCC: None
Gases
Combustion products
such as CO, COj, Nj,
H2O, chlorides,
fluorides, sulfur
oxides
Particulates
Aluminum oxides and
ash from fuel com-
bustion
Wet scrubber effluent
containing chlorides,
fluorides, sulfur
oxides, and aluminum
oxides
Tramp iron
Pollution Control
Afterburners
Wet scrubbers
None Reported
None Reported
-------
Table 3.1-14. (CONTINUED)
Process & Pollution Control
Air Emissions
Aqueous Effluents
Solid Wastes
3.1-6 Hot Dross Processing
EPA SCC: None
Particulates
Dusts and fumes
produced by fluxing
None Reported
Dry dross .-'jid collected
particulates
Pollution Control
B.iKli'iiisen
Landfill
1.1-7 Dry Hilling
EPA SCC: Hone
Particulates
Large amounts of
dust, aluminum oxides
Gases
Ammonia
Wet scrubber effluent
which contains aluminum
oxides, hydrated alumina,
and soluble chloride,
fluoride and potassium
salts
Collected particulates
that are high In alumina
Pollution Control
Baghouses
Met Scrubbers
Settling Ponds
Landfill
3.1-8 Wet Hilling
EPA SCC: None
Particulates
Possibility of
particulate
emissions from
drying
High volumes of waste-
water containing salts,
alumina, aluminum sulfates,
chlorides, cyanides,
fluorides, ananonia,
calcium, copper, mag-
nesium, nickel, sodium,
potassium, zinc, cadmium,
lead, naganese, oils,
grease, phenols and
nitrates
Alumina and aluminum fines
and particulates from the
settling ponds
Pollution Control
Hone Reported
Settling ponds followed
by chemical treatment
Landfill
3.1-9 Roasting
EPA SCC: None
Particulates
Particulates from
charring carbonaceous
materials
Hone Reported
Charred scrap
Pollution Control
Hone Reported
Landfill
-------
Table 3.1-14. (CONTINUED)
Process & Pollution Control
Air Emissions
Aqueous Effluents
Solid Wastes
3.1-10 Aluminum Sweating
EPA SCC: 3-04-001-01
Pollution Control
i
cr>
Cases
HC1 resulting from
hydrolysis of
aluminum chloride ftux,
combustion products
Part ictil ill«,»
Smoke from incomplete
combustion of organics.
Fumes of magnesium and
zinc oxides and
aluminum chloride.
Aluminum trioxlde
particulates
Afterburners
Baghouses
None Reported
Iron containing aluminum
and nonferrous metals such
as zinc, magnesium, and lead
. Landfill
' 3.1-11 Reverberatory (Chlorine)
Smelting-Refining
EPA SCC: 3-04-001-03
(Furnace)
3-04-001-04
(ChlorlnatIon)
Pollution Control
Cases
Chlorine, hydrogen
chloride, combustion
products, and aluminum
zinc, and magnesium
chlorides .
Particulates
Aluminum oxide and
other metals
Wet Scrubbing
Baghouses
Electrostatic pre-
cipitators
Coated baghouses
Metal cooling water and
wet scrubber effluent.
Wastewater contains
sulfates, chlorides,
cyanides, fluorides,
aluminum, calcium,
copper, magnesium, nickel,
sodium, sine, cadmium,
lead, manganese, phenols,
oils and greases.
Settling Ponds
Drosses and skimmings,
particulate control residuals
and wastewater sludge.
Solid waste have components
similar to the aqueous
wastes.
Landfill
-------
Table 3.1-14. (CONTINUED)
Process & Pollution Control
Air Emissions
Aqueous Effluents
Solid Wastes
3.1-12 Reverbertory (Fluorine)
Smelting-Refining
EPA SCC: 3-04-001-03
Gases
Hydrogen fluoride,
aluminum fluoride,
magnesium fluoride,
silicon, tetra-
fluorlde, and com-
bustion products
Particulates
Dusts containing
aluminum oxide and
other metals
Metal cooling water and
wet scrubbing. Waste-
water constituents are
similar to Process 3.1-11.
Drosses and skimmings,
particulate control
residuals, and wastewater
sludge. Solid waste
constituents are similar
to those in Process 3.1-11.
Pollution Control
Wet Scrubbers
Bughouses
Settling Ponds
Chemical treatment
Landfill
3.1-13 Crucible Smeltlng-Reflnlng
EPA SCCs 3-04-001-02
Air emission con-
stituents are similar
to Process 3.1-11.
However, they are much
less.
Aqueous emission con-
stituents are similar to
Process 3.1-11
Solid emission constituents
are similar to Process 3.1-11.
Pollution Control
Wet Scrubbers
Baghouses
Settling Ponds .
Chemical treatment
Landfill
3.1-14 Induction Smelting-Refining
EPA SCC: None
Air emissions con-
stituents are similar
to Process 3,1-11 with
the exception of com-
bustion products
Process cooling water
having constituents
similar to Process
3.1-11
Drosses and skimmings
having constituents similar
to Process 3.1-11
Pollution Control
Baghouses
None Reported
Landfill
-------
3.2
Secondary Copper, Brass and Bronze Segment
3.2.1 Segment Description - Secondary Copper, Brass and Bronze
These industries are grouped together for purposes of
this profile because a considerable overlap exists between the
population of companies producing secondary copper and those
processing bronze and brass. Differences which do exist in these
operations are associated mainly with the quality of the raw
materials used and the degree of processing required. Generally,
the secondary copper industry deals with less pure raw materials
and produces a more refined, pure copper product, whereas brass
and bronze processors take cleaner scrap and primarily remelt,
modify and cast alloys which involve less purification and re-
fining. However, the basic processing steps and the fundamental
material, copper, remain the same.
According to Appendices D and E (Volume III), there are
108 companies in the secondary copper, bronze and brass segment.
The majority of this industry's production is concentrated in the
northeast quadrant of the country. Other areas of concentration
are the Upper Midwest and the more urban and industrial East,
North Central and Middle Atlantic regions.
The 1972 Census of Manufacturers (US-276) reports that
the total number of employees in the secondary copper industry is
4900, of which 3500 are production workers. The total value of
shipments is given as $692.6 million, representing about one-
third of the total value of the secondary nonferrous metals
industry.
-65-
-------
The total secondary copper production in 1972 was
543,600 metric tons (599,300 short tons) (US-276). Another .
source (CA-305) gives 532,000 metric tons (587,000 short tons)
for 1972, increasing from 346,000 metric tons (381,000 short
tons) in 1961, with projected copper recoveries of 800,000
metric tons (900,000 short tons) by the year 2000. The 1975
estimate given in the Commodity Data Summaries 1976 (US-357)
was 313,000 metric tons. Those variations in production values
probably reflect the different bases used in classifying this
industry segment.
Another set of total figures which undoubtedly reflect
the use of different classification criteria has been reported.
The information summarized below represents the quantities of
copper recovered from scrap by various industries in 1973 (SC-303)
Metric Tons Short Tons
Secondary smelters 260,821 287,555
Brass mills 550,377 606,791
Primary copper industry 296,563 326,961
Total 1,107,761 1,221,307
A breakdown of copper-base scrap consumption and copper recovery
from scrap by these three industries is presented in Table 3.2-1.
The combined pressures of an increasing price of primary
copper and environmental concerns have stimulated an interest
in this industry in a variety of lower-grade raw materials. New
recovery technology is being continually developed; e.g.,
recovery of copper from junked automobiles (DE-187). It has
been reported that 9 to 15 kg (20-30 lb) of copper can be re-
covered per automobile (CA-305).
-66-
-------
Table 3,2-1. DOMESTIC CONSUMPTION OF AND RECOVERY FROM PURCHASED
NEW AND OLD COPPER-BASE SCRAP IN 1971 THROUGH 1973
Consumption, metric tons (short tons)
Period
Primary Producers
Secondary Smelters
Brass 1
Mills
Total
New Scrap
Old Scrap
New Scrap
Old Scrap
New Scrap
Old Scrap
1971
214,291
253,784
106,583
277,520
568,792
24,513
1,445,483
(236,263)
(279,806)
(117,512)
(305,976)
(627,114)
(27,026)
(1,593,697)
1972
237,348
246,744
100,959
288,218
645,784
31,531
1,550,584
(261,685)
(272,044)
(111,311)
(317,771)
(712,000)
(34,764)
(1,709,575)
1973
281,429
266,263
100,603
264,134
662,138
42,365
1,616,932
(310,275)
(293,555)
(110,915)
(291,208)
(730,007)
(46,707)
(1,782,667)
(Copper recovered in unalloyed and alloyed form from purchased scrap)
1972 192,022 132,909 58,170 207,995 485,828 29,419 1,106,343
(211,711) (146,537) (64,135) (229,322) (535,643) (32,435) (1,219,783)
1973 185,130 111,433 62,269 198,551 510,014 40,363 1,107,760
(204,106) (122,855) (68,652) (218,903) (562,291) (44,500) (1,221,307)
Source: SC-303
-------
No specific information was available on variations
in the sizes of copper, bronze and brass processing facilities;
however, this segment is probably typical of the secondary
industry as a whole. The largest group of companies in the
secondary industry is the 100-249 employee class , with the next
largest groups being those in the 50-99 and 20-49 employee
classifications (US-276).
Raw Materials
The copper scrap comprising the great bulk of the raw
materials used by this industry can be first classified ad new
(61 percent), i.e., produced in the fabrication of finished products,
or old (39 percent), from obsolete, worn out or salvaged articles
(US-357). Old scrap sources include wire, plumbing fixtures, electrical
machinery, automobiles and domestic appliances. Other materials with
copper values include slags, drosses, foundry ashes and sweepings from
smelters and copper processing industries. A detailed classification
adopted by the National Association of Secondary Materials Industries
is given in Table 3.2-2 and definitions for each classification are
given in Section 3.2-4. The major single source of copper scrap
(47 percent) comes from copper wire and tubing (FI-103).
A tabulation of the compositions of various standard
brasses and bronzes is given in Table 3.2-3. This table gives
the compositions of both raw materials and products for secondary
brass and bronze processors. Although specifications for scrap
impurities such as wire insulation, oil, grease, and paint are
not given, these associated materials are often significant con-
tributors to the pollution potential of the scrap.
In addition to the scrap, other raw materials necessary
for secondary copper processing include fluxes of boron minerals,
old glass and salt; minor alloying components such as phosphorus,
tin, and lead (if required); and leaching or reaction agents such
as sulfuric acid and ammonium carbonate.
-68-
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TABLE 3,2-2
NATIONAL ASSOCIATION OF SECONDARY MATERIALS INDUSTRIES
CLASSIFICATIONS FOR COPPER-BEARING SCRAP MATERIALS
No. Designation
1. No. 1 copper wire
2. No. 2 copper wire
3. No. 1 heavy copper
4. No. 2 copper
5. Light copper
6. Refinery brass
7. Copper-bearing scrap
8. Composition or red brass
9. Red brass composition turnings
10. Genuine babbitt-lined brass bushings
11. High-grade - low-lead bronze solids
12. Bronze paper mill wire cloth
13. High-lead bronze solids and borings
14. Machinery or hard brass solids
15. Machinery or hard brass borings
16. Unlined standard red car boxes (clean journals)
17. Lined standard red car boxes (lined journals)
18. Cocks and faucets
19. Mixed brass screens
20. Yellow brass scrap
21. Yellow brass castings
22. Old rolled brass
23. New brass clippings
24. Brass shell cases without primers
25. Brass shell cases with primers
26. Brass small arms and rifle shells, clean fired
27. Brass small arms and rifle shells, clean muffled (popped)
28. Yellow brass primer
29. Brass pipe
30. Yellow brass rod turnings
31. New yellow brass rod ends
32. Yellow brass turnings
33. Mixed unsweated auto radiators
34. Admiralty brass condenser tubes
35. Aluminum brass condenser tubes
36. Muntz metal tubes
37. Plated rolled brass
38. Manganese bronze solids
Source; NA-182
-69-
-------
TABLE 3.2-3 NOMINAL CHEMICAL SPECIFICATIONS FOR
BRASS AND BRONZE INGOT INSTITUTE STANDARD
ALLOYS
Alloy
Mo.
Classification
Cu.S
Sa.:
Pb.S
Fa.:
ai.s
i
i ni.i
•Si.I
x^t:
U
Tin broaso
(8.0
10.0
2.0
IS
Ila broaso
sa.o
8.0
4.0
ZJl
Loadod cla broaso
BS.O
6.0
1.5
4.0
a
lairiari cla broaso
87.0
8.0
1.0
4.0
2C
loaded tin broaso
87.0
10.0
1.0
2.0
34
¦ith-lead cla broaae
sa.o
10.0
10.0
3B
llffc-laad cla brooxa
S3.0
7.0
7.0
3.0
X
Il(fa-lead tin broaso
ss.o
5.0
9.0
1.0
3D
Ulb-load cla brooza
7S.0
7.0
13.0
3E
llth-lead cla braoso
71.0
S.O
24.0
4A
loaded rod brass
SS.O
5.0
5.0
S.O
*1
Leaded rod brass
S3.0
4.0
6.0
7.0
U
Load ad seal-red brui
S1.0
3.0
7.0
9.0
SB
Loaded seal-red brass
76.0
2.5
6.5
15.0
64
Loaded follow brass
72.0
1.0
3.0
24.0
t>
Load ad yellow bras J
67.0
1.0
3.0
29.0
6C
Loodod Tallow braao
61.0
1.0
1.0
37.0
7A
Hannnaai broaso
s».o
1.0
1.0
37.0
1.0
0.6
0.5
U
Bl-acroafth manj. broaxs
57. 5
39.0
1.0
1.0
1.5
SB
Il-ocraotch aaaf. broaze
64.0
24.0
3.0
5.0
3.5
BC
ai-acron*ch aon*. broaxo
64.0
24.0
3.0
5.0
3.5
9*
Alialaua broaso
SS.O
3.0
9.0
9B
Atualnna broaso
89.0
1.0
10.0
9C
broua
SS.O
4.0
u.o
2.0
0.5
9D
Alualaua broaxo
81.0
4.0
11.0
4.0
3.0
10A
Loodod alckol braao
57.0
2.0
9.0
20.0
12.0
10B
Loodod alckol bras*
60.0
3.0
5.0
16.0
16.0
111
Loadod alckol broass
64.0
4.0
4.0
S.O
20.0
11B
Loaded alckol broazs
66.5
S.O
1.5
2.0
2S.0
12X
Silicon broaxo
88.0
S.O
1.5
4.0
1.5
121
Silicon braao
82.0
14.0
4.0
Sours: 3A-1S2
-70-
-------
Products
The classification system used to describe the various
grades of recovered copper roughly corresponds to the various
stages of the secondary refining process. In order of increasing
copper purity, these grades of recovered copper are (NA-182):
1) "White metals" (babbit, lead, and solder)
from sweating process. These may be used
internally or sold to another processor.
2) Copper powder
3) Copper shot
4) Fire-refined copper
5) Electrolytic-refined copper
These products will be discussed in more detail as outputs from
the various processes.
.Brass and bronze product specifications have been
established by the Brass and Bronze Ingot Institute (Table 3.2-3).
Brass is a copper-base alloy with zinc while bronze is a copper-
tin alloy; additional alloying agents may include lead, iron,
aluminum, nickel, silicon, and manganese. These alloys are
marketed as hardeners, generally in the form of ingots.
Copper consumption including brass and bronze in 1970
has been characterized as follows (CA-305):
Use
Percent of Market
Wire mills
Sheet (copper and brass)
Rod and mechanical wire (brass)
Foundries (brass and bronze)
Plumbing tube (copper)
Commercial tube (copper and brass)
Other
42.2
15.3
13.9
10.5
6.6
7.8
3.5
-71-
-------
A breakdown by market category is as follows
Category
Percent
Electrical and electronics
Building construction
Consumer and general
Industrial machinery and
equipment
Transportation
29.0
22.0
20.8
16.7
11.5
A more complete characterization of products, raw
materials, and companies is given in Appendices, A, B, and C.
The secondary copper, bronze and brass industry is
typical of the secondary nonferrous metals industry as a whole
in that it is fragmented and difficult to characterize. Quali-
tatively, the various processes making up the industry are well
known but hard data on process operating parameters and pollutant
emission characteristics are very limited. Consequently, the
process descriptions in this section include many information
gaps. In cases where process data was available, an attempt
has been made to assess that information in terms of its con-
sistency with known physical and chemical data and principles.
given in Figure 3.2-1. In some cases, processes with similar
characteristics have been combined, with differences noted in
the text of the description.
3.2.2 Segment Analysis - Secondary Copper
A process flow sheet for the segment as a whole is
-72-
-------
rmrm*nmn
kbimm i cashho
s
Ul
NOHTrM
*¦
FIGURE 3,2-1
PROCESS FLOW DIAGRAM FOR THE COPPER, BRASS AMD BRONZE SEGMENT
OF THE SECONDARY NONFERROU3 METAL INDUSTRY
-------
SECONDARY COPPER, BRASS MP BRONZE
PROCESS NO. 3.2-1
Stripping and Sorting
Function - Feed scrap is segregated for further treatment
by a variety of processes adapted to the considerable number of
input materials. Generally, scrap is sorted on the bases of its
copper content and cleanliness. Clean brass and bronze scrap
may be manually separated for charging directly to a melting and
alloying furnace. Ferrous components can be separated magnet-
ically. Insulation and lead cable coverings are stripped by hand
or by specially designed machines. As part of the hand sorting
process, large items may be broken apart by desoldering.
Input Materials - Insulated and lead-covered cable and
wire; miscellaneous scrap.
Operating Parameters - Not applicable.
.Utilities - Energy to drive wire strippers, conveyors
and magnets.
Waste Streams -
Solid waste is the only waste stream produced. These
wastes include plastic and fiber insulation, lead cable
sheathing and ferrous scrap rejections. Control
practices include landfill disposal, incineration of
combustibles and sale of scrap metals to other pro-
cessors if they cannot be used in-house.
Atmospheric emissions would result from the incineration
of combustibles.
EPA Source Classification Code - None
-74-
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SECONDARY COPPER, BRASS AND BRONZE
PROCESS NO. 3.2-2
Briquetting and Crushing
Function - Varieties of relatively clean scrap are
compacted for easier handling in the smelting step. The machinery
used in this process includes hydraulic baling presses, hammer
mills and ball mills.
Input Materials - Clean wire, thin plate, wire screen,
borings, turnings, and chips.
Operating Parameters - Not available.
Utilities - Energy required to drive the equipment.
Waste Streams - There may be some dust emissions con-
sisting of dirt, organic compounds and metal particles. These
can be collected in hoods for conveyance to the plant particulate
control system.
EPA Source Classification Code - None
-75-
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SECONDARY COPPER, BRASS AND BRONZE
PROCESS NO. 3.2-3
Shredding
Function - In this step, the separation of copper
wire from insulation and other materials is accomplished
by reducing the size of the entire mixture. The pulverized
material is then sorted by air or hydraulic classification with
magnetic separation of any ferrous materials. Copper oxidation
and the pollution problems resulting from insulation burning (Pro-
cess No. 3.2-6) are thus avoided. The process steps are: (a)
cutting into a 20-40 mm (3/4 - 1-1/2") random length in a knife-
type primary granulator, (b) reduction to 5-7 mm (3/16 - 1/4")
particles in a secondary granulator, (c) screening to separate
fine copper, unliberated wire and insulation chunks, and (d)
gravity separation into clean copper, insulation and recyclable
middle fractions (ST-339).
Input Materials - This process is designed primarily
for cleaning insulated wire. More heterogenous wires such as
grease-filled cable and bimetallic wire were not within the
state-of-the-art in 1971 (SI-108). A more detailed process
separating copper and aluminum was proposed in 1972 (ST-339),
but the present state-of-the-art is poorly defined.
Operating Parameters - Not readily definable.
Utilities - Energy to drive granulators, shaking
screens, and fans.
-76-
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Waste Streams
¦ Particulate matter containing significant amounts of
both insulation and metal appears in the air used in
classification. Cyclones or baghouses may be used
to collect this particulate matter. Recycling of the
air in a closed system is also practiced (ST-339).
* Noise pollution is a possibility if proper acoustic
shielding is not provided, since shredding system dBa
levels may reach 100-110 (ST-339).
" Shredded insulation material is the major solid waste
produced. This material can be disposed of in a
landfill or reclaimed, either as various plastic
fractions or other materials such as HC1 from poly-
vinyl chloride insulation (ST-339).
EPA Source Classification Code - None
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SECONDARY COPPER, BRASS AND BRONZE
PROCESS NO. 3.2-4
Grinding and Gravity Separation
Function - This process accomplishes the same function
as Process No. 3.2-3, Shredding, but uses an aqueous separation
medium and different input materials. The unit operations
involved in this process are grinding, screening and gravity
separation. Their purpose is the concentration of the metal
value in the scrap so that subsequent thermal refining steps will
not be overburdened with waste material.
Input Materials - A wide variety of materials with
metal values are processed: (a) slags, (b) drosses, (c) skimmings,
(d) foundry ashes, (e) spills, (f) sweepings and (g) baghouse
dust. These materials may be supplied by either an outside source
or other processes at the secondary smelter.
Operating Parameters - Equipment used includes size
reduction'machines (hammer and ball mills), screening devices
and floatation cells. Specific operating conditions for these
equipment items were not found.
Utilities - Power is required to operate the size
reduction equipment, shaking screens and pumps. Water makeup
is required in the floatation media preparation step.
Waste Streams -
Particulate emissions resulting from grinding and
screening include fluxing materials, dirt and small
amounts of metals. No quantitative industry-wide
emission factors are available. Conventional bag-
houses or cyclones should be effective in reducing
these particulate emissions.
-78-
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" The liquid waste stream would contain any soluble
constituents of the gangue material, which encompasses
a great variety of possibilities. Even if the water
in the gravity separation step is recycled, there will
be a blowdown/sludge stream requirement which will
create disposal problems. Examples of waste water
compositions are presented in Table 3.2-4.
' Solid wastes from the screening step also are present.
No information is available on waste amounts and
compositions.
EPA Source Classification Code - None
-79-
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Table 3.2-4, CHARACTER OF WASTEWATER FROM SLAG QUENCHING AND
GRANULATION OR SLAG MILLING AFTER SETTLING
Product
HT/day
(ton/day)
Utter flaw
l/dny
Plant 9 - Wet Loading
Intake _____
Cone., Cone.
•S/1 mg/l
Diachain
kg/Iff m/ton)
Plant 11 - Groai Loading
Cone.,
»g/l
Cone,
¦g/1
Plschataa
flant 38 - Het Loadiaa
kg/MT
larilm
(lb/ton)
lgtlti
Cone.,
¦g/1
Cone.,
¦g/l
Dl«ttam
Hint 39 - Met Loading
uniiM
kg /W flk/ton)
Intake _____
Cone., Cone..
¦g/1 og/1
Discharge
Loading
kg/m
Copper
«.I
(50J
3,000,000'
All or
~lir
U»9)
545.400
AIIot
9.7
<10.7)
72,670
«151
TITS
(48)
662,400 617,000
(gal/Jay)
(792.000)
(144.100)
(19,200)
(175,000)
(163,000)
Constituent
Alkalinity
no
190
1.125
<1.650) —
2965
14.976
(29.95)
71.33
104.67
0.250
(0.50)
685
733
0.681
COD
21.2
25.3
0.139
(0.278) —
18.333
22.67
0.032
(0.064)
Solids, Total
1294
1620
21.389
(41.18) —
3900
19.695
(39.39)
V21.J
6456
45.210
(90.42)
Solid*, dlaa.
64
336
18.013
(36,OS) —
387.67
2953.7
19.224
(38.45)
1,754
1,852
1.39
Sollda, susp.
1211
1284
3.510
(7.020) —
630
3.182
(6.364)
33.67
3502.3
25.986
(51.97)
21,405
22,980
326
•roe
63.3
268.67
1.539
(3.078)
Phosphorus
0.029
0.031
0.0001
(0.0002)
Jk
0.293
0.403
0.001
(0.002)
1.0
1.0
HLC
Cyanide
0.005
0.004
MIC
—
Mr
—
0.053
0.163
0.001
(0.001)
Ant Smony
0.142
0.111
HLC
<0.0
2.8(7
0.021
(0.042)
Arsenic
0.001
0.001
MIX
<0.02
<0.02
HLC
Boron
2.4#
2.60
0.001
(0.001)
0.667
6.0
0.040
(0.080)
Cadalw
0.111
0.067
HLC
—
0.11
0.0006
(0.0012)
0.067
1.683
0.012
(0.012)
Copper
0.093
0.071
HLC
—
19.78
0.100
(0.10)
12
1250
9.275
(18.55)
0.10
0.11
0.00014
Chrmtlua
0.120
0.001
(0.001)
Iron
0.005
0.007
HLC
—
1J.0
0.066
(0.132)
1.833
163.667
1.212
(2.424)
13
14
0.0142
Lead
0.297
0.192
HLC
—
23.0
0.116
(0,232)
5.333
916.67
6.835
(13.67)
0.9
1.0
0.0014
Hanganaae
0.325
0. 399
0.0005
(0.001)
0.467
43.33
0.321
(0.642)
0.05
0.05
NI.C
Mercury
0.0004
0.0003
HLC
<0.001
0.002
0.001
(0.002)
Nickel
0.024
< 0J0
HLC
—
0.3$
0.002
(0.004)
0.133
18.0
0.134
(0.268)
Zinc
1.492
0.622
HLC
—
80.35
0.631
(1.262)
6.0
983.33
7.322
(14.64)
0.16
0.17
0.00014
Oli and greaae
1
1
HLC
11.0
23.333
0.092
(0.184)
0
0
HLC
pH
« 12
9.8
7.4
8.53
9.35
9.35
(il/ton)
(1.36)
(2.78)
(652)
(0.00028)
(0.0214)
(0.0028)
(0.00028)
* Slag granulation.
b Slag Billing.
Bsti«ate
-------
SECONDARY COPPER, BRASS AND BRONZE
PROCESS NO. 3.2-5
Drying
Function - Here volatile organic contaminants including
cutting fluids, oils and greases are removed. This process is
distinguished from wire burning (No. 3-2-6) in that the contaminants
are not burned. Various types of heating equipment are used, such
as rotary kilns, ovens, and muffle furnaces. This process is
similar to the Burning/Drying Process in the Aluminum Segment.
Input Materials - Organic contaminated scrap such as
borings, turnings and chips are fed to this process.
Operating Parameters - A heating temperature which is
high enough to drive off or decompose the organic contaminants
is used. The length of the drying period will vary according
to the contaminant volatility and type of scrap. Specific data
for this operation were not found.
Utilities - Oil or gas to fire the drying furnaces.
Waste Streams - Only atmospheric emissions are produced,
but they can be significant. Depending on the organic matter,
the gases may contain chlorides, sulfur oxides, flourides and
hydrocarbons. Particulate matter could include metals, soot
and condensed heavy organics. Quantitative emission factors
are not available. An afterburner is almost mandatory to control
the organic emissions. HC1 and HF can be removed by alkaline wet
scrubbing. Non-combustible particulates can be removed by
scrubbers or baghouses.
EPA Source Classification Code - None
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SECONDARY COPPER, BRASS AND BRONZE
PROCESS NO. 3.2-6
Insulation Burning
Function - This process is intended to separate insula-
tion and other coatings from copper wire by burning these
materials in furnaces. The wire scrap is charged in batches to
a primary ignition chamber. Combustion is started with auxiliary
fuel and air. Volatile combustion products are then passed to
a secondary combustion chamber or afterburner. Further treatment
of combustion gases in a scrubber or baghouse is desirable if
significant quantities of particulates or hazardous vapors are
generated in this process. In most cases, the insulation burning
is self-sustaining, but there can be problems with wire coated
with polyvinyl chloride, fluorocarbon polymers or other flame
resistant plastic formulations. If non-combustible inorganic
materials such as fiberglass or ceramics are present they must
be removed separately, either before or after burning.
'Although the shredding method of wire treatment (Process
No. 3.2-3) has been proposed as a relatively non-polluting
replacement for this process, new developments in wire burning
equipment promise considerable improvements over older designs
(CO-368). It is claimed that a properly designed wire burner
with full pollution control capabilities can recover copper from
wire scrap for about l%c lb. Data on pollutant removal effi-
ciencies for various wire and insulation types were not found.
Input Materials - The total combustible content of the
wire scrap can vary up to 50 percent by weight. Host commercial
wire contains 20-35 percent combustibles. Wire smaller than 14
gauge is not usually burned since excessive copper oxidation
losses are sustained with small wires. Wire and cable larger
than about one inch in diameter is also not burned but stripped
-82-
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by hand or machine. The combustible portion of the wire scrap
may include a considerable variety of materials, such as rubber,
paper, natural and/or artificial fibers and fabrics, asphaltic
materials or plastics such as polyethylene and polyvinyl
chloride. Metallic and/or non-metallic inorganic fillers may also
be present. Plastics formulated for flame resistance may have
bromine, phosphorus and antimony compounds up to levels of
several weight percent.
Operating Parameters - The size of the wire batches
charged to the furnace varies from approximately 20 kg (50 lb)
to 450 kg (1000 lb) or more, with 110 kb (250 lb) being typical
(DA-069). A representative set of wire incineration furnace
operating parameters are given in Table 3.2-5.
Table 3.2-5. WIRE INCINERATION FURNACE
OPERATING PARAMETERS
Feature
Recommended Value
Gas velocities
9.1 m/sec (30 ft/sec)
Primary chamber
outlet temperature
700°C (1300°F)
Afterburner
final temperature
870°C (1600°F)
Residence time in stack
@ maximum temperature
0.50 sec
Combustion air
Primary
Secondary
100% excess
1007. of theoretical
Source: DA-069
-83-
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Utilities - The major requirements are primary fuel
for initial charge heating during primary combustion and
secondary fuel in the afterburner to insure complete combustion.
A typical value for natural gas fuel usage in secondary burning
is 0.445m3/kg (7.13 ft3/lb). The amount of primary fuel required
will vary widely depending upon the type of wire burned and furnace
design.
Electrical power is required to operate scrubber pumps
and exhaust fans; makeup water and scrubbing reagents are required
if wet effluent gas scrubbers are employed.
Waste Streams - Air pollution is the principal
problem, with liquid wastewater from scrubbers (if used) and
solid non-combustible insulation residues being the only possibil-
ities for liquid and solid pollutants.
' It is not possible to accurately characterize wire-
burning process air emissions since the present extent
¦of pollution control technology application is not
known. It was estimated in 1971 that wire burning was
essentially completely uncontrolled. An uncontrolled
particulate emission factor of 137 kg/metric ton of
scrap wire processed (274 lb/short ton) has been
estimated to be representative of the wire burning
process (SH-106).
Proper design and operation of the incineration system
is essential if pollutant emissions are to be minimized.
This is particularly true of the secondary burning step.
The data shown in Table 3.2-6 clearly indicate that
wire burning emissions vary significantly depending
upon whether secondary burning is used. Even with
efficient secondary combustion however, the problems
-84-
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Table 3.2-6.
WIRE INCINERATOR EFFLUENTS (TYPICAL
RUBBER-COVERED WIRE CHARGE)
Parameter or Effluent
Secondary
Burners Off
Secondary
Burners On
Charge wt, kg (lb)
Combustibles in charge, wt %
Ash in charge, wt %
Smoke opacity, %
Particulates at 12% C02, gm/Nm3
(gr/ft3)
Particulates, kg/metric ton
combustible (lb/short ton)
0 0
Mixing chamber temp., C ( F)
Aldehydes, ppm
Hydrocarbons, ppm
Nitrogen oxides, ppm
Sulfur compounds
as SO2, ppm
100 (220)
35
6
Constant 100% black
66 (29)
178 (350)
416 (781)
105
640
11
.012
106 (234)
16
6
0-25%
.59 (.26)
17.5 (35)
1027 (1881)
5
8
25
.0039
Source: DA-069
-85-
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of HC1 from polyvinyl chloride, HF from fluorocarbon
plastics, and inorganic particulates from non-
combustible fillers remain. These emissions can be
controlled by conventional alkaline wet scrubbers
and baghouses. However, wet scrubbers have been
shown to be poor substitutes for complete combustion
' (LA-186).
Liquid waste from this process consists of scrubber
blowdown liquid. The nature of this material and hence
the water treatment options required will be determined
by the contaminants present in the furnace effluent
gas stream.
Solid wastes result from baghouse residues and
possibly scrubber sludges.
EPA Source Classification Code - None
-86-
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SECONDARY COPPER, BRASS & BRONZE
PROCESS NO. 3.2-7
Sweating
Function - The removal of low-melting components from
scrap is accomplished in this process by heating the scrap to
a controlled temperature which is just above the melting point
of the metals to be sweated out (usually solder). In this
industry segment, the primary metal, copper, is generally not
the melted component. This is in contrast to aluminum and lead
sweating, where these primary metals are usually melted to
recover them from scrap containing still higher melting
impurities (principally iron).
The copper sweating process is carried out in various
types of furnaces according to the type of scrap and the difficulty
of removal of the low-melting impurities. There are four basic
types of furnaces (NA-182).
• Sloping hearth - The scrap is charged to a preheated
furnace, heated to the desired tempature, raked over
the hearth and discharged. Solder, lead, and other
low-melting constituents are collected in a pit.
Reverberatory - Scrap which is more difficult to sweat
may be charged to this type of furnace which is usually
equipped with a shaking grate. The molten solder
falls through the grate to a collecting sump.
Pot - The scrap is dipped in a pot of molten alloy and
removed after its low-melting constituents are released.
Tunnel - The scrap passes continuously on a conveyer
through the tunnel furnace. At the furnace exit, the
-87-
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hot scrap Is dumped on tilting screen to remove
solder not lost in the furnace proper.
Input Materials - Typical scrap to be sweated includes
automobile radiators» plumbing fixtures, gas meter boxes and
radio chassis. The material to be sweated out of the scrap is
usually a relatively small constituent of the total scrap.
Operating Parameters - Most copper sweating furnaces
are operated in the temperature range 340-370°C (650-700°F).
In this temperature range, tin and lead are melted but not zinc
and aluminum. Higher temperatures are avoided to minimize losses
of valuable metals through melting and/or oxidation and to avoid
fume formation problems.
Utilities - The principal utility requirement is fuel
to heat the scrap. The amount of fuel required is a function
of furnace design, operating procedure, scrap type, and product
quality specifications.
Waste Streams - The principal emissions are atmospheric,
consisting of metal and metal oxide dusts and fumes, and partly
oxidized organic material from scrap contaminants such as anti-
freeze, oil, grease and paint. The metals and metal oxides
present in the furnace effluent gas are mainly the volatile
compounds such as lead, tin, and zinc, a common constituent of
copper and its alloys. There is no firm data available, but
particulate emissions from automobile radiators sweating operations
have been estimated at 7.5 kg/metric ton of scrap processed
(15 lb/short ton) (SH-106). These emissions may be controlled
by baghouses, wet scrubbers or electrostatic precipitators.
EPA Source Classification Code - None
-38-
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SECONDARY COPPER, BRASS & BRONZE
PROCESS NO. 3.2-8
Ammonium Carbonate Leaching
Function - Copper values can be recovered from relative-
ly clean scrap by leaching and dissolution in a basic ammonium
carbonate solution. Cuprlc ions in an ammonia solution will
react with metallic copper to produce cuprous ions, which can
be reoxidized to the cupric state by air oxidation. After the
crude solution is separated from the leach residue, the copper
is recovered (in the oxide form) by steam distillation (Process
No. 3.2-9). Although this process has not been widely used in
the past, it represents an attractive alternative to traditional
thermal processes with their associated atmospheric emission
problems.
A recent study has been made to define important
process parameters and possible improvements in this process
(ST-343). Increased efficiency was obtained by (1) more agita-
tion and flow during leaching, and (2) the use of elemental
sulfur to convert the cuprous ion in solution to the sulfide
precipitate. In this form it can be further processed by
primary copper ore techniques.
Input Materials - Scrap with copper values which are
difficult to separate (such as starters, electric motors and
transformers) can be treated with this process. Feed material
should be relatively clean of dirt, grease and other foreign
matter. Ammonium carbonate and air are used for leaching and
oxidizing.
Operating Parameters - The leaching is conducted in
the temperature range of 30-40°C (86-104°F). The maximum copper
dissolution rate occurs in the range of 10-30 gm/liter of cupric
ion. The best ratio of NH3 to C02 in solution is 4 to 1 (ST-343).
-89-
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Utilities - Energy is required only for solution
heating and recirculation (pumping).
Waste Streams -
* The only gaseous emissions from this process are
ammonia and carbon dioxide escaping from the solutions.
NH3 losses can be minimized by exercising proper con-
trol over the leaching solution pH.
" Solid wastes include residual scrap containing un-
leaehed metals which can be sold or processed further
and leach residues which must be disposed of.
Since the leaching liquor is recycled there should be
little chance for liquid wastes, except for inter-
mittent recharging and disposal.
EPA Source Classification Code - None
-90-
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SECONDARY COPPER, BRASS AND BRONZE
PROCESS NO. 3.2-9
Steam Distillation
Function - Copper is recovered from the leaching
liquor of the ammonium carbonate process (No. 3,2-8) by steam
distillation and precipitation as copper oxide. Boiling the
solution precipitates the copper as the oxide. This material
is dried before it is sent to other processes such as hydrogen
reduction (No. 3.2-10) or blast furnace/reverberatory smelting
(No. 3.2-12) for copper recovery.
Input Materials - Copper as cupric ion in an ammonium
carbonate solution from the leaching process (No, 3.2-8).
Operating Parameters - The steam distillation may
take place at either atmospheric or higher pressures.
Utilities - Steam to heat the solutions and drier
fuel.
Waste Streams -
. Atmospheric emissions may include ammonia and carbon
dioxide (see Process No. 3.2-8) and also copper
oxide particulates in the drier offgases.
. If the liquid waste is recycled to the leaching
process, there is little potential for water pollution
from this step.
EPA Source Classification Code - None
-91-
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SECONDARY COPPER, BRASS & BRONZE
PROCESS NO. 3.2-10
Hydrothermal Hydrogen Reduction
Function - As an alternative to the steam distillation
(Process No. 3.2-9), the copper may be recovered from the solution
of Process No. 3.2-8 by hydrothermal hydrogen reduction. The
heating of the liquor under hydrogen pressure precipitates the
copper as a powder. The copper is filtered, washed, dried and
sintered under a hydrogen atmosphere. The powder is then ground
and screened. The spent liquor is recycled to the leaching pro-
cess (No. 3.2-8).
Both the steam distillation and hydrogen reduction pro-
cesses have the disadvantages of expensive equipment and complex
operation (ST-343). Thus a search has been made for alternative
methods of recovery from the leaching liquor such as reaction with
elemental sulfur to produce copper sulfide, as noted in Process
No. 3.2-8.
Input Materials - Copper-containing ammonium carbonate
solution from Process No. 3.2-8, containing 10-30 g/liter of copper.
Operating Parameters - The hydrogen reduction is carried
out at a temperature of 160 - 205°C (325-400°F) and 3.58 megapascals
(500 psig).
Utilities - Energy is required for heating, drying,
pulverizing and screening.
-92-
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Waste Streams
. The gaseous emissions contain ammonia and carbon
dioxide as for Processes 3.2-8 and 3.2-9, plus
hydrogen.. Additional metallic particulate emissions
resulting from the copper powder processing steps can
be controlled by baghouses. The amounts of all of
these components are expected to be minor but no data
are available.
. The soent liquor is a possible liquid pollutant, but
it is mostly recycled to the leaching process.
-93-
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SECONDARY COPPER, BRASS & BRONZE
PROCESS NO. 3.2-11
Sulfuric Acid Leaching
Function - Scrap copper is dissolved in hot sulfuric
acid to form a copper sulfate solution for feed to the electro-
winning process (No. 3.2-18). An alternative product is crys-
talline copper sulfate. After digestion in a hot aerated sul-
furic acid solution, the undissolved residue is filtered off.
Lead and tin impurities precipitate and are carried off with
the residue. Other metallic impurities are best controlled by
scrap selection and/or pretreatment.
Input Materials - Various kinds of heavy and light
scrap can be digested by this method. Another common type of
feed is shot obtained by quenching of molten copper from a
refining furnace.
Operating Parameters - Temperatures are usually main-
tained around 90°C <2008F). The reaction is considered complete
when the pH has fallen to 1 or 2 (0.1 - 0.01 eq H+/1), indicating
excess acid. Sparging air is maintained at a volumetric rate per
minute equal to the volume of the material in the digestion tank.
Utilities - Data on heat and power requirements for this
process were not found.
Waste Streams -
The spent or bleed-off acid will contain a wide range
of metallic and nonmetallic contaminants.
-94-
-------
' The undissolved residues which are usually disposed
of via landfill could result in a secondary pollution
problem.
" Sulfuric acid mist from the digester is usually con-
trolled by using demisters similar to those developed
for use in sulfuric acid manufacturing operations.
EPA Source Classification Code - None
-95-
-------
SECONDARY COPPER, BRASS AND BRONZE
PROCESS NO. 3.2-12
Blast Furnace/Reverberatory Smelting
Function - This process uses equipment and techniques
similar to primary copper ore smelting to produce black copper
containing 70-80 percent copper for further refining. The feed
is scrap of lower grade than that input to-other secondary re-
fining processes. The overall chemical process in the blast
furnace is based on the reduction of copper by the coke fuel and
the carbon monoxide formed from it. Impurities such as iron com-
bine to form a slag which separates from the molten copper. The
slag and metal mixture is tapped to a reverberatory furnace for
separation.
The scrap is charged at the top of the blast furnace and
proceeds downward, meeting reducing gases from the fuel at the
bottom. The oxides of the base metals either dissolve in the slag,
fume off, or are reduced and dissolve in the copper. The black
copper product may contain zinc, lead, tin, bismuth, antimony,
iron, silver, nickel, or other metals contained in the scrap.
Sulfur in the coke or other feed materials reacts with the copper
to form copper sulfide; this reaction can be largely avoided by
using low-sulfur coke. The molten product may be cast into ingots
or transferred in the molten state to the converter (Process No.
3.2-13) for further purification (SP-058, NA-182).
Input Materials - The scrap types normally charged to a
blast furnace include high iron content copper and brasses, motor
armatures, foundry sweepings, slags, drosses, and skimmings. It
was estimated in 1961 that the minimum profitable copper content
was about 30 percent (SP-058). In 1973, it was reported that
feeds containing as little as 10 percent copper can be processed
economically (BU-184). Lower grade output of previous scrap pre-
paration processes are used as inputs to the blast furnace.
-96-
-------
The coke used as a fuel and reducing agent comprises
about 10 percent of the charge. Limestone and millscale (iron
oxides) are added to form an iron silicate slag for fluxing pur-
poses .
Operating Parameters - The copper is maintained some-
what above its melting point of 1083*C (1981*F), usually in the
range of 1090-1150'C (2000-2100'F). The slag leaves the furnace
at about 1040°C (1900°F) (DA-069). A typical secondary blast
furnace has a maximum diameter of 1.3 meters (50 inches), tapering
to 1 meter (40 inches) at the top, with a water jacketed section
3 meters (10 feet) high. Air flow required is 38-46 cubic meters/
min per sq meter of area~at the bottom (125-150 ft3/min/ft2).
The nominal capacity of such a unit would be in the range of
55-65 metric tons/day (60-70 short tons/day).
Utilities - The coke charge supplies both process heat
and acts as a reducing agent. Cooling water is also required by
the furnace, and in the ingot casting, and shot quenching opera-
tions .
Waste Streams -
Pollutants in the blast furnace effluent gases may include
carbon monoxide, sulfur oxides, nitrogen oxides, and
possibly halogens and hydrocarbons if these components
are present as scrap contaminants. No quantitative
information on these emissions is available.
The particulate emissions consist of fly ash, soot,
and metal and metal oxide fumes. Total particulate
emissions have been estimated to be 25 kg/metric ton
(50 lbs/short ton) (SH-106). One set of analytical
data for collected baghouse dust has been cited (NA-182):
-97-
-------
CONSTITUENT
PERCENT
Zinc
58-61
Lead
2-8
Tin
5-15
Copper
0.5
Antimony
0.1
Chlorine
0.1-0.5
Pollution control equipment usually includes settling
chambers, baghouses, and possibly electrostatic pre-
cipitators and wet scrubbers.
' The amount of slag formed is typically 5 'percent of the
total charge. A typical slag analysis is given below
(SP-058):
CONSTITUENT PERCENT
Iron oxide (FeO) 29
Calcium oxide (CaO) 19
Silica (Si02) 39
Zinc (Zn) 10
Copper (Cu) 0.8
Tin (Sn) 0.7
" Liquid wastewater will result from furnace cooling,
ingot casting and slag quenching operations. Dis-
charge rates can be minimized by recycling this water.
EPA Source Classification Code - 3-04-002-01
-98-
-------
SECONDARY COPPER, BRASS & BRONZE
PROCESS NO. 3,2-13
Converter Smelting
Function - The black copper from Process No. 3.2-12
(blast furnace/reverberatory smelting) can be further refined
to increase the copper content from 70-80 percent to 90-99 per-
cent, Host of the product, called blister copper, is poured and
cast or transferred molten to Process No. 3.2-15 (Fire Refining).
A lesser amount of direct product is produced in the form of
copper shot by water quenching.
The process steps involved in converter smelting are
(a) charging with molten black copper, (b) blowing with air to
oxidize copper sulfides and other metals, (c) deslagging, (d)
secondary blowing, and (e) final slag skimming. Most of the
reactions are exothermic; thus no external heat is required. In
fact, if the iron content of the black copper feed is too high,
pure copper scrap may have to be added to the charge to help
keep the temperature under control. A flux containing silica
(e.g., sand or glass) is usually added to react with iron oxides.
This forms an iron silicate phase which is removed as slag.
Converters are pear-shaped or cylindrical steel shells
lined with ceramic bricks of calcined magnesite. Openings (tuyeres)
are provided for blowing air into the molten charge when the con-
verter is tilted to the blow position.
Input Materials - Black copper of 70-80 percent purity,
air, and silica flux are the feed materials. The impurities in
the black copper may be iron or copper sulfides, and various other
metals and metal oxides such as tin, lead, antimony and zinc.
-99-
-------
Operating Parameters - The temperature is probably main-
tained a few hundred degrees above the melting point of copper, as
in previous molten copper processes.
Utilities - No energy is required except incidental
equipment motor power if the copper is supplied in the molten state.
Waste Streams -
' The major sources of particulate emissions are the
charging/melting and blowing steps, which are estimated
to each have emission factors on the order of 23 kg/
metric ton of copper charged (50 lb/short ton) (VA-091).
The composition of these particulates is not known,
however, these solids are expected to contain signif-
icant quantities of volatile metals such as zinc, tin,
and lead. The usual form of control device is a
baghouse.
The baghouse dust constitutes a solid waste stream,
which may have sufficient metal value to warrant re-
cycling to a previous purification process. The slag
represents another solid waste stream, which contains
mainly iron and other metals in a silica matrix. Slag
may either be recycled or disposed of in a landfill if
metal values are not sufficient.
Wastewater from ingot cooling and slag quenching is
also generated. Typical effluent water quality data
for a metal cooling operation is given in Table 3.2-7.
EPA Source Classification - None
-100-
-------
Table 3.2-7. CHARACTER OF WASTEWATER FROM MOLTEN
METAL COOLING AND QUENCHING
Plant 9 - Net Loading
Intake Discharge
Cone., Cone., Loading
mg/1 mg/1 kg/HI (lb/con)
Copper
45.3
(50)
3t000,000a
(792,000)
170
182
0.795
23.2
11.2
NLC
1294
1238
NLC
64
31
NLC
1231
1208
NLC
0.029
0.023
NLC
0.005
0.005
NLC
0.142
0.126
NLC
<0.001
<0.001
NLC
2.46
2.35
NLC
0.111
0.098
NLC
0.098
0.069
NLC
<0.005
<0.007
NLC
0.297
0.223
NLC
0.325
0.372
0.003
<0.0004
<0.0002
NLC
0.024
0.019
NLC
1.492
0.821
NLC
<1
<1
0
8.3
8.3
Casting time estimated at 4 hours.
Source: EN-462
-101-
-------
SECONDARY COPPER, BRASS & BRONZE PROCESS NO, 3.2-14
Electric Crucible Smelting
Function - Feed containing low copper values can also
be refined by using electric heating and pure oxygen in place
of air for oxidation. The same sequence of charging, melting,
blowing and skimming used in the previous two processes is also
used here. An advantage of electric heating is the fact that it
gives better control over the exothermic portions of the process.
Input Materials - Feed can be either pretreated scrap,
raw scrap or black copper from Process No. 3.2-12 (Blast furnace/
reverberatory smelting).
Operating Parameters - Temperatures which are closer
to the melting point of copper are possible. Volumes of gases
will be about one-fifth of those required by processes using air
blowing.
Utilities - Electric power is used for heating, but
data concerning the amount used and the efficiency of using
electric power rather than coke or natural gas fuels are not
available.
Waste Streams -
* Gaseous emissions of sulfur and nitrogen oxides will
be present, but in reduced volume in comparison to
other smelting processes. Soot and carbon monoxide
will be absent. Particulate emissions may also be
lower but not data are available.
-102-
-------
Liquid wastes will be similar to the analogous coke-
fueled process.
Slag removed represents a solid waste stream, which aay
be recycled or disposed of in a landfill.
EPA Source Classification Code - None.
-103-
-------
SECONDARY COPPER, BRASS & BRONZE
PROCESS NO. 3.2-15
Fire P>.efining
Function - In this process, the blister copper from
Processes 3.2-13 and -14 is further refined to the 99.9 percent
purity level. Clean, high grade copper scrap can also be charged
directly to this process, which is very similar to the refining
process used in the primary copper refining industry. In the
fire refining process, copper may be either partially refined to
a grade suitable for electrolytic purification (Process No. 3.2-
16) or further refined to the practical limit in order to achieve
a commercially salable product. About 14 percent of the total
primary and secondary copper produced in this country is marketed
as fire-refined copper (KI-048).
Fire refining can be accomplished in either a rever-
beratory or a cylindrical tilting furnace. The latter type is
generally used with molten copper feed to cast anodes for electro-
lytic refining. The production of ingot and bar or the melting
of blister copper ingots is usually done in a reverberatory furnace.
Both oxidation of impurities and reduction of residuals
are done in this process. The process steps are (a) charging the
furnace; (b) melting in an oxidizing atmosphere; (c) skimming the
slag; (d) blowing with air or oxygen until the melt is about 10
percent Cu20 (1 percent total oxygen); (e) adding a reducing agent
and surface cover of charcoal or coke; (f) reducing the oxygen
content to 0.03-0.05 percent by forcing green maple or birch logs
beneath the surface of the melt, agitating the melt with reducing
gases such as hydrogen, hydrocarbons, and carbon monoxide formed
during the "poling" process; (g) reskimming the slag, and (h) cast-
ing the melt into ingots, wire bars, and other products.
-104-
-------
An innovation recently introduced is the use of natural
gas as a reducing agent. Fluxes may be added to extract impurities,
e.g., sodium carbonate for arsenic and antimony. A variety of
specialized reagents and procedures are available for copper
material of special composition (SP-058). The control, sampling,
and entire course of the process is still very much an art based
on long experience.
Input Materials - The blister copper from Processes
3.2-13 and -14, which is the main feed material, has a copper
content in the range of 90-99 percent. Scrap charge must be
clean and relatively impurity-free. A green pole requirement
of 50 kg/metric ton of copper processed (100 lb/short ton) has
been cited (NA-182). Fluxing agents are also inputs to this process
Operating Parameters - The capacities of furnaces used
i inifr i in i i i Mil i .ii i —
for this operation usually range from 90-360 metric tons
(100-400 short tons).
Utilities - Heat is necessary to keep the charge molten,
but no specific data on fuel or cooling water requirenents were
found.
Waste Streams -
* Atmospheric emissions include sulfur oxides in the
oxidation phase and hydrocarbons in the reducing phase.
Particulates should include carbon from the flux cover
and metal oxides. No data for these emission sources
were found.
* Solid wastes include the slag and skimmings which could
present a disposal problem if not recycled or sold
-105-
-------
for recovery of other metal values. Arsenic, anti-
mony, magnesium and aluminum may be present.
* The usual liquid wastes for cooling and quenching
operations are produced.
EPA Source Classification Code - None
-106-
-------
SECONDARY COPPER, BRASS & BRONZE
PROCESS NO. 3.2-16
Electrolytic Refining
Function - Copper cathodes of 99.9+ percent purity may
be produced as the output of the fire refining process (No. 3.2-
15). Oxygen is the major impurity in the product, usually at the
0.03-0.05 percent level. As the anodes dissolve in the electrolysis
process, impurities either dissolve in the electrolyte or fall
to the bottom of the containing cell to be collected as slime.
The cathodes produced are melted and cast in subsequent processes.
The electrolyte accumulates both soluble anode impurities
(antimony, bismuth, lead, nickel, iron and zinc) and copper. Other
metals collect on the cathode as scale or fall to the bottom as
sludge.
A replacement rate of up to 75 percent a month of the
electrolyte is circulated to liberator cells with insoluble lead
anodes and'copper starter sheets as cathodes. The copper content
is reduced in two stages to 0.1-0.2 g/1. The copper produced is
recycled to the appropriate process, depending on its purity. The
effluent liquid may be concentrated and processed for further metal
recovery, e.g., nickel as nickel sulfate.
The slime from both the primary electrolysis and the
electrolyte purification step is filtered or centrifuged. This
material may either be processed further for precious metal
recovery or discarded.
Input Materials - Feed materials other than copper
anodes which are required are sulfuric acid and copper sulfate
for electrolyte solution makeup. Various additives, mainly glue
(0.02-0.06 kg/metric ton of cathodes or 0.04-0.12 lb/short ton),
are used to suppress coarse crystal growth and entrapment of
impurities in the cathode material.
-107-
-------
Operating Parameters - Typical values are given in
Table 3.2-8.
TABLE 3.2-8. TYPICAL ELECTROLYTIC COPPER KIFINISG PARAMETERS
Parameter Value
Anode weight, kg (lb)
275
(600)
Slimes fall, kg/metric ton
-------
' Much or all of the wastewater may be treated and re-
circulated. One available analysis of electrolytic
process wastewater is given in Table 3.2-9,
EPA Source Classification Code - None
-109-
-------
TABLE 3.2-9. CHARACTER OF WASTEWATER FROM
ELECTROLYTIC REFINING
Pollutant Loading, kg/Kkg metal produced3
Parameters
Suspended solids
0.0048
Cadmium
NLCb
Copper
3 x 10"8
Lead
1.7 x 10'
Mercury
NLCb
Nickel
1.7 x 10*
Zinc
3 x 10"7
Oil & grease
NLCb
pH
8.0
Discharge would be outflow from treatment plant of
excess wash-down water in event of breakdown and is
not continuous.
b NLC - no loadings calculable.
Source: EN-462
-110-
-------
SECONDARY COPPER, BRASS & BRONZE
PROCESS NO. 3.12-17
Melting and Alloying
Function - Clean scrap is melted and reformulated, if
necessary, to produce the desired alloy. A minimum of purifica-
tion is assumed in this process. The major process steps are
charging, melting, fluxing, alloying, pouring, and casting.
This process is used almost exclusively in the brass
and bronze production area. Its emissions are markedly different
from melting essentially pure copper. Brass melting in particular
has higher particulate emissions from volatile constituents, zinc
and lead, while bronzes, which contain tin as the chief additive,
are more akin to pure copper. A table of standard alloy composi-
tions was given in Table 3.2-3.
A number of different types of furnaces are used for
this process, depending mainly on the desired batch size and total
throughput. Large tonnages of standard alloys are most practically
handled by stationary reverberatory furnaces, while the more flex-
ible rotary furnace is limited to moderate tonnages. Small quan-
tities of special alloy compositions are often produced in gas-
or electric-fired crucible furnaces. The use of more closely
controlled electric induction furnaces for special high-grade
alloys is increasing in some plants.
Input Materials - Clean, selected bronze and brass
scrap is charged to the furnace along with fluxes and alloys to
bring the resulting mixture to the final composition desired.
Fluxes both protect the melt from atmospheric oxidation and react
with and dissolve impurities. Fluxing materials used include
sodium chloride, charcoal, boron-containing minerals, lime, glass
and sand. Sometimes an additive is both a flux and alloying
-111-
-------
constituent, such as a 10-15 percent phosphorus-copper alloy.
The phosphorus reacts with oxygen in the melt to form the vola-
tile Pi»0 io. Gases such as nitrogen are sometimes bubbled up
through the melt to remove some solid impurities by entrainment
and to sweep out gaseous impurities.
Operating Parameters - Although operating conditions
vary widely depending primarily on the desired product, the values
noted below for a large reverberatory furnace are typical (SP-058),
Overall dimensions:
Molten metal depth:
total weight of scrap charged:
Average charge composition,
weight percent:
Product composition,
weight percent:
Flux composition:
Slag weight:
Slag composition, percent
Time cycle:
Charging and melting
Refining
Pouring
Metal recovery
Pouring temperatures
3.7 x 8.1 a (12 z 26.5 ft)
1.0 m (3 ft)
86,000 kg (190,000 lb)
82 Cu, 4 Sn, 5.26 Pb, 0.6 Hi, 0.6 Fe,
0.18 Sb, 0.07 S, 0.0-0.05 Al,
nil As, 7.25 Zn.
84.5 Cu, 4.4 Sn, 5.25 Pb, 5.4 Zn,
0.15 Fe, 0.22 Sb.
230 kg (500 lb) broken window glass,
removed after melting; 230 kg
(500 lb) again added, plus sand
as long as it dissolves freely.
Total flux of 1800 kg (4000 lb).
4500 kg (10,000 lb)
20 zinc oxide, 20 iron oxides, 35
silicon oxides, 20 copper prills,
5-8 copper oxide, small amounts
of cidmium oxide, magnesium oxide,
and aluminum oxide.
30 hours
10 hours
8 hours
93 percent
1090-1200°C (2000-22008F) (DA-069)
Utilities - For the above large reverberatory furnace
the natural gas fuel usage over the entire 48 hour cycle is
0.319 Nm3/kg of charge (5.11 ft3/lb) (SP-058).
-112-
-------
Waste Streams -
Atmospheric emissions include fuel combustion products,
organic scrap contaminants and particulate matter
such as fly ash, soot and metal oxides. The most
hazardous of these emissions in most cases would be
the oxides of the volatile metals, lead and zinc; thus,
the severity of this problem depends somewhat on the
lead and zinc content of the melt. For typical red and
yellow brass furnaces» the zinc oxide content of the
particulate fume averages about 60 percent, and lead
oxide 15 percent (DA-069). Lesser constituents include
tin, copper, cadmium, and silicon.
Overall emissions have been cited for various types
of furnaces (SI-106):
PARTICULATE EMISSIONS
FURNACE lb/metric ton lb/short ton
Blast 9 18
' Crucible 6 12
Cupola 36.5 73
Electric induction 1 2
Reverberatory 35 70
Rotary 30 60
However, other parameters such as pouring temperature,
collection hood design, and furnace details can affect
emissions.
The typical particulate collection device is the bag-
house, which has been operated routinely at collection
efficiencies of about 95% (DA-069). Electrostatic
precipitators have been tried but have been unsatis-
factory on lead and zinc particulate fumes. Wet
scrubbers also have efficiency problems when compared
to baghouses, collecting only 50-65% in some tests
cited (DA-069).
-113-
-------
' Solid wastes include slags (discussed under Operating
Parameters) and baghouse"dusts. If not recycled to
recover their metal values, these are normally disposed
of in a landfill.
" Liquid wastes are produced as a result of ingot cooling.
An example of a wastewater analysis has been given in
Table 3.2-7.
EPA Source Classification Code -
Crucible furnace 3-04-002-02
Cupola furnace 3-04-002-03
Electric induction furnace 3-04-002-04
-114-
-------
SECONDARY COPPER. BRASS & BRONZE
PROCESS NO. 3.2-18
Electrolytic Winning
Function - Copper is recovered as impure cathodes from
a copper sulfate solution which usually comes from Process No.
3.2-11, Sulfuric Acid Leaching. The copper produced must be
further treated "(by Process No. 3.2-16) to attain the purity
of regular electrolytic copper.
In this process, spent electrolyte is continuously bled
from the system, regenerated, and recycled. The process steps are:
(a) preparing the electrolyte, (b) electrolyzing copper or starter
sheet cathodes (c) removing the cathodes, (d) cleaning the cath-
odes, (e) replacing the starter strips, and (f) regenerating the
electrolyte (NA-182).
Input Materials - Copper sulfate solution from acid
leaching or other sources and copper starter sheets for initial
cathodes are required.
Operating Parameters - Basically the same as Process
No. 3.2-16.
Utilities - Basically the same as Process No. 3.2-16.
Waste Streams - There will be spent electrolyte
residues similar to those of Process No. 3.2-16. There will
also be slimes formed from other metals. The amount of slimes
formed will depend on the type of scrap originally leached with
sulfuric acid (NA-182).
EPA Source Classification Code - None.
-115-
-------
SECONDARY COPPER, BRASS & BRONZE
PROCESS NO. 3.2-19
Electrolytic Powder Production
Function - Pure copper powder is produced by electro-
lysis from the copper cathodes from Process No. 3,2-16. The pro-
cess steps are (a) use pure copper from Process No. 3.2-16 as
anodes, (b) deposit copper powder, (c) filter the powder from
the cell electrolyte, (d) recycle the electrolyte, (e) rinse
the powder, (f) dry the powder in a reducing atmosphere of
hydrogen and carbon monoxide, and (g) classify, blend and
package the powder.
Input Materials - Cathode copper from Process No. 3.2-16.
Utilities - Electricity is required as the driving
force for the electrolytic reaction, and heat is required to
dry the powder.
Waste Streams -
Atmospheric emissions include gaseous emissions of
carbon monoxide, hydrogen, and possibly arsine and un-
burned fuel, and particulate emissions consisting of
dusts from the drying and powder handling steps. No
quantitative data are available.
" Liquid wastes similar to the spent electrolyte solutions
generated in Processes 3.2-16 and 3.2-18 are produced.
EPA Source Classification Code - None
-116-
-------
3.2.3 Environmental Impact - Secondary Copper, Bronze and Brass
The secondary copper, bronze, and brass segment of the
secondary nonferrous metals industry is a source of nearly all
known types of pollutants. These include (a) particulates,
(b) organic and inorganic gases, (c) metal-contaminated liquid
wastes, and (d) solid wastes.
A major pollutant is the metal and metal oxide dusts
emitted in the gases from sweating furnaces, converters, and
crucibles. These particulates are primarily zinc and lead oxides,
since these are the most volatile elements present in appreciable
amounts. The emission levels depend on the lead and zinc contents
of the scrap as well as the operating temperature of the equipment
used. These dusts are usually controlled with baghouses.
Organic pollutant emissions come from the burning of wire
insulation and the volatilization of any solvents, grease, or paint
contaminating the original scrap. Properly designed and operated
afterburners can usually minimize these emissions.
Emissions of inorganic gases such as sulfur dioxide,
hydrogen chloride, arsine, and nitrogen oxides result from the
various combustion processes used in this segment. Sulfur
dioxide emissions are generally lower than those of the primary
metal industry because the raw materials used contain less sulfur.
The sulfur in the coke used in the blast furnaces as fuel and
reducing agent is the major source of the sulfur dioxide emissions.
No information was found to make a general assessment of the
magnitude of the nitrogen oxides emissions. The results of an
industry survey of air pollution control practices are presented
in Table 3.2-10.
-117-
-------
TABLE 3.2-10.
AIR POLLUTION CONTROL PROCESSES USED BY SMELTERS AND
REFINERS OF SECONDARY BRASS AND BRONZE AND SECONDARY COPPER
NUMBER OF PLANTS (PERCENT)
CONTROL PROCESS
Brass and
Bronze
Copper
Combined
Plants surveyed
37
7
44
Only dry air pollution control
(electrostatic)
2r (57)
2 (29)
23
(52)
Only wet air pollution control
7 (21)
1 (14)
8
(20)
Both types of air pollution
control
1 ( 3)
4 (57)
5
(11)
No air pollution control
4 (11)
1 (14)
5
(11)
No data supplied
3
0
3
Source: EN-378
Aqueous waste streams from from three main sources:
(1) liquid wastes from acidic or basic scrap leaching and dis-
solution processes, (2) waste cooling water from pouring and
casting operations, and (3) liquid wastes and slimes from
electrolytic refining. Much of "the wastewater is either re-
cycled or .disposed of rather than being extensively treated.
There should not be a serious problem if the ultimate long-term
disposal is non-polluting. The results of a survey of industry
practices is given in Table 3.2-11.
The solid wastes include sludges and slimes from
electrolytic and gravity separation processes, as well as fluxes,
drosses, and skimmings from the various metal purification fur-
naces. As with liquid wastes, those solids not recycled can be
disposed of safely, but there are no data on current disposal
practices. Disposal methods which formerly were acceptable,
such as deep ocean dumping or landfills, may in many cases no
longer be allowed.
-118-
-------
TABLE 3.2-11
SUMMARY OF WASTEWATER HANDLING PRACTICE AND DISPOSITION
USED BY SECONDARY COPPER INDUSTRY
NUMBER OF PLANTS (PERCENT)
Brass and
CONTROL PROCESS Bronze Copper Combined
No water use
1
( 3)
0
1
( 2)
No treatment, discharge to
Stream
2
( 6)
1
(14)
3
( 7)
Sewer
8
(24)
0
8
(18)
Treat, discharge to
Stream
1
( 3)
1
(14)
2
( 5)
Sewer
4
(11)
0
4
( 9)
Recycled, no discharge
10
(29)
1
(14)
11
(25)
Recycled, some discharge to stream
Periodic
3
( 9)
2
(29)
5
(11)
Continuous
1
( 3)
1
(14)
2
( 5)
Recycled, some discharge to sewer
Periodic
5
(14)
0
5
(11)
Continuous
2
( 6)
1
(14)
3
( 7)
Source*. EN-378
Table 3.2-13 lists the air, aqueous and solid emissions
from feach process in this segment and the reported control
equipment for each type of emission from the processes. The
health and environmental effects of thse emissions are summarized
in Section 5 of this volume. Since the emissions from this segment
are similar in many respects as the emissions from the lead segments,
there is sufficient health data (ON-02G) to warrent control of these
multimedia emissions by the best available control technology.
-119-
-------
Table 3.2-12. PROCESS POLLUTANT AND CONTROL SUMMARY
COPPER, BRASS, AND BRONZE SEGHEMT
Process & Pollution Control
3.2-1 Stripping and S&rtlng
EPA SCC: None
Pollution Control
Air Emissions
Particulates
Incineration of
solid waste com-
bustibles
None Reported
Aqueous Effluents
None Reported
Solid Wastes
Plastic and fiber insulation,
lead cable sheathing, and
Iron scrap
Landfills
Incineration of combustibles
Recycle metal values
3.2-2 Brlquetting and Crushing
EPA SCC: None
Pollution Control
Hinor amounts of
dirt, organic com-
pounds, and metallic
particles
Baghouses
None Reported
None Reported
O
3.2-3 Shredding
EPA SCC: None
Pollution Control
Insulation and
metallic particulate
matter
Baghouses
None Reported
Insulation
Landfills
Reclaimed
3.2-4 Grinding and Gravity
Separation
EPA SCC: None
Pollution Control
Particulate matter
consisting of fluxes,
dirt, and metals
Baghouses
Spent gravity separation
water consisting of P,
Cn, Sb, As, B, Cd, Cu,
Fe, Pb, Hn, Ni, Zn,
grease and oil
None Reported
Screening residues consisting
of dirt, fluxes, and metals
None Reported
3.2-5 Drying
EPA SCC: None
Pollution Control
Ga3es
Chlorides, fluorides,
sulfur oxides, hydro-
carbons
Particulates
Soot and heavy
organics
Afterburners
Wet Scrubbing
Baghouses
Wet Scrubber effluent
Collected particulates
Settling Pond
Landfills
-------
Table 3.2-12 (CONTINUED)
Process & Pollution Control
Air Emissions
Aqueous Effluents
Solid Wastes.
3.2-6 Insulation Burning
EPA SCC: None
Pollution Control
Gases
IIC1, HF, chlorides,
fluorides, hydro-
carbons, aldehydes,
and sulfur-oxides
Particulates
Noncombustible fillers
Met scrubbing
Baghouses
Afterburners
Scrubber effluent
Neutralizing
Collected particulates
Landfills
3.2-7 Sweating
EPA SCC: None
Pollution Control
Particulates consisting
of metals and metal
oxides, partially
oxidized oil, grease,
and paint and sine
oxide
Baghouses
Wet scrubbers
Electrostatic pre-
cipitators
Wet scrubber effluent
Settling ponds
Collected particulates
Landfills
3.2-8 Ammonium Carbonate
Leaching
EPA SCC: None
Pollution Control
Ammonia, and carbon
dioxide
None Reported
Blow-down leaching
liquor
None Reported
Leaching residues
Recycled
Landfills
3.2-9 Steam Distillation
EPA SCC: None
Pollution Control
Ammonia, carbon
dioxide, and minor
amounts of copper
None Reported
Blow-down leaching
liquor
None Reported
None Reported •
-------
fable 3.2-12 (CONTINUED)
Process & Pollution Control
Air Emissions
Aqueous Effluents
Solid Wastes
3.2-10 Hydrothermal Hydrogen
Reduction
EPA SCC: None
Pollution Control
Gases
Amnion ia, carbon
dioxide
Particulates
Copper Powder
Baghouses
None Reported
Collected particulates
Recycled
3,2-11 Sulfuric Acid Leaching
¦'.nl I iir I<¦ m: Id Mist
Blow down acid
Undissolved residues
EPA SCC: None
Pollution Control
Mist eliminators
None Reported
Landfills
3.2-12 Blast Furnace/Reverberatory
Smelting
EPA SCC; 3-04-002-01
Cases
Carbon monoxide,
sulfur oxides, halo-
gens (chlorine) and
hydrocarbons
Particulates
Fly ash, soot, and
metal and metal oxide
fumes consisting of Zn,
Pb, Sn, Cu, and Sb
Scrubber effluent process
cooling water and ingot
casting spray and slag
quenching water
Collected particulates and
slag consisting if iron
oxide, calcium oxide, silica,
sine, copper, and tin
Ppllution Control
Settling chamber
Baghouses
Electrostatic pre-
cipitators
Wet aerubbers
Settling ponds for scrubber
effluent
None reported for
aqueous emissions
Landfills
f
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Table 3.2-12 (CONTINUED)
Process S> Pollution Control
Air Emissions
Aqueous Effluents
Solid Wastes
3.2-13 Converter Smelting
EPA SCC: Hone
Pollution Control
Metallic particulates
of zinc, tin, and
lead
Baghouses
Water from ingot cool- "
ing and slag quenching
consisting of P, Cn,
_Sh, As, B, Cd, Cr, Cu,
Fe, Pb. Mn, Kg, Ni, Zn,
oil, and grease
. None Reported
Collected particulates
Recycled
3.2-14 Electric Crucible Smelting
EPA SCC: None
Sulfur oxides and
nitrogen oxides
Refer to Process Ho.
3.2-13
None Reported
Pollution Control
None Reported
None Reported
3.2-15 Fire Refining
EPA SCC: None
Cases
Sulfur oxides and
hydrocarbons
Particulates
Fluxes and metallic
oxides
Refer to Process
No. 3.2-12
Slag and skimmings containing
As, Sb, Mg, and Al
Pollution Control
None Reported
None Reported
Recycled
Landfills
3.2-16 Electrolytic Refining
EPA SCC: None
Arsine and possibly
phospliine
Blow-down water con-
taining nitrates,
sulfates, sulfites
chlorides, Ai, Sb, As,
Cd, Ca, Cr, Cu, Fe, Pb,
Mg, Mn, Ilg, Ni, K, Ag,
Na, Zn, oil and grease.
Slimes
Pollution Control
None Reported
None Reported
Sold for precious metal content
Recycled
Landfills
-------
Table 3.2-12 (CONTINUED)
Process (• Pollution Control
Air Emissions
Aqueous Effluents
Solid Wastes
J,2-17 Melting and Alloying
EPA SCCi
Crucible Furnace: 3-04-002-02
Cupola Furnace: 3-04-002-03
Electric Induction
Furnace: 3-04-002-04
Cases
Combustion products
and hydrocarbons
Particulates
Organic scrap, fly
aslt, soot, metal
oxides, such as
zinc and lead
oxides, tin, copper,
cadmium, and sllcon
Refer to Process No.
3.2-13
Slags and collected
particulates
Pollution Control
Baghousea
Refer to Process No.
3.2-13
Recycled
Landfills
3.2-18 Electrolytic Winning
EPA SCC: Hone
Refer to Process
No. 3.2-16
Refer to Process
No. 3.2-16
Refer to Process No. 3.2-16
3.2-19 Electrolytic Powder
Production
EPA SCC: None
Cases
Carbon monoxide,
hydrogen and arsine.
Particulates
Copper powder
Refer to Process No.
3.2-16 *
Refer to Process No. 3.2-16
Pollution Control
None Reported
1
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3-2-4 Copper-bearing scrap definitions (SP-058)
No. 1 copper wire shall consist of clean, untinned. tin-
coated, unalloyed copper wire and cable, not smaller than No. 16
B & S wire gage, free of burnt wire which is brittle. Hydraulically
briquetted copper subject to agreement.
No. 2 copper wire shall consist of miscellaneous; unalloyed
copper wire having a nominal 96 percent copper content (minimum
94 percent) as determined by electrolytic assay. Should be free
of the following: Excessively leaded, tinned, soldered copper
wire; brass and bronze wire; excessive oil content, iron, and non-
metallics; copper wire from burning, containing insulation; hair
wire; burnt wire which is brittle; and should be reasonably free
of ash. Hydraulically briquetted copper wire subject to agreement.
No. 1 heavy copper shall consist of clean, unalloyed, un-
coated, copper clippings, punchings, bus bars, commutator segments,
and wire not less than one-sixteenth of an inch thick, free of burnt
wire which is brittle; but it may include clean copper tubing.
Hydraulically briquetted copper subject to agreement.
No. 2 copper shall consist of miscellaneous, unalloyed
copper scrap having a nominal 96 percent copper content (minimum
94 percent) as determined by electrolytic assay. Should be free
of the following: Excessively leaded, tinned, soldered copper scrap;
brasses and bronzes; excessive oil content, iron and nonmetallics;
copper tubing with other than copper connections or with sediment;
copper wire from burning, containing insulation; hair wire; burnt
wire which is brittle; and should be reasonably free of ash.
Hydraulically briquetted copper subject to agreement.
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Light copper shall consist of miscellaneous, unalloyed
copper scrap having a nominal 92 percent copper content (minimum
88 percent) as determined by electrolytic assay and shall consist
of sheet copper, gutters, downspouts, kettles, boilers, and
similar scrap. Should be free of the following: burnt hair wire;
copper clad; plating racks, grindings, copper wire from burning,
containing insulation; radiators; fire extinguishers; refrigerator
units; electrotype shells; screening; excessively leaded, tinned,
soldered scrap; brasses and bronzes; excessive oil, iron, and non-
metallics; and should be reasonably free of ash. Hydraulically
briquetted copper subject to agreement. Any items excluded in
this grade are also excluded in the higher grades above.
Refinery brass shall contain a minimum of 61.3 percent
copper and maximum 5 percent iron and to consist of brass and bronze
solids and turnings, and alloyed and contaminated copper scrap.
Shall be free of insulated wire, grindings, electrotype shells
and nonmetallics. Hydraulically briquetted material subject to
agreement.
Copper-bearing scrap shall consist of miscellaneous copper-
containing skimmings, grindings, ashes, irony brass and copper,
residues and slags. Free of insulated wires; copper chlorides;
unprepared tangled material; large motors; pyrophoric material;
asbestos brake linings; furnace bottoms; high lead materials;
graphite crucibles; and noxious and explosive materials. Fine-
powdered material by agreement. Hydraulically briquetted material
subject to agreement.
Composition or red brass shall consist of red brass scrap,
valves, machinery bearings and other machinery parts, including
miscellaneous castings made of copper, tin, zinc, and/or lead.
Should be free of semired brass castings (78 to 81 percent copper);
railroad car boxes and other similar high-lead alloys; cocks and
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faucets; gates; pot pieces; ingots and burned brass; aluminum
and manganese bronzes; iron and nonmetallics. No piece to measure
more than 12 inches any one part of weight more than 100 pounds.
Red brass composition turnings shall consist of turnings
from red brass composition material and should be sold subject
to sample or analysis.
Genuine babbitt-lined brass bushings shall consist of red
brass bushings and bearings from automobiles and other machinery,
shall contain not less than 12 percent high tin base babbitt,
and shall be free of iron-backed bearings.
High-grade - low-lead bronze solids. It is recommended
these materials be sold by analysis.
Bronze paper mill wire cloth shall consist of clean genuine
Fourdrinier wire cloth and screen having a minimum copper content
of 87 percent, minimum tin content of 3 percent, and a maximum
lead content of 1 percent, free of stainless steel and Honel metal
stranding.
High-lead bronze solids and borings. It is recommended
that these materials be sold on sample or analysis.
Machinery or hard brass solids shall have a copper content
of not less than 75 percent, a tin content of not less than 6 per-
cent, and a lead content of not less than 6 percent - nor more than
11 percent, and total impurities, exclusive of zinc, antimony,
and nickel of not more than 0.75 percent; the antimony content
not to exceed 0.50 percent. Shall be free of lined and unlined
standard red car boxes.
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Machinery or hard brass borings shall have a copper
content of not less than 75 percent, a tin content of not less
than 6 percent, and a lead content of not less than 6 percent -
nor more than 11 percent, and the total impurities, exclusive
of zinc, antimony, and nickel of not more than 0.75 percent;
the antimony content not to exceed 0.50 percent.
Unlined standard red car boxes (clean journals) shall
consist of standard unlined and/or sweated railroad boxes and
unlined and/or sweated car journal bearings, free of yellow
boxes and iron-backed boxes.
Lined standard red car boxes (lined journals shall consist
of standard babbitt-lined railroad boxes and/or babbitt-lined car
j oumal bearings, free of yellow boxes and iron-backed boxes.
Cocks and faucets shall consist of mixed clean red and
yellow brass, including chrome or nickel-plated, free of gas
cocks, beer faucets, and aluminum and zinc-base die-cast material,
and contain a minimum of 35 percent semired.
Mixed brass screens to consist of clean mixed-copper, brass,
and bronze screens and to be free of excessively dirty and painted
material.
Yellow brass scrap shall consist of brass castings, rolled
brass, rod brass, tubing and miscellaneous yellow brasses, includ-
ing plated brass. Must be free of manganese-bronze, aluminum-
bronze, unsweated radiators or radiator parts, iron, excessively
dirty and corroded materials.
Yellow brass castings shall consist of yellow brass cast-
ings in crucible shape, no piece to measure more than 12 inches
over any one part; and shall be free of brass forgings, silicon
bronze, aluminum bronze and manganese bronze, and not to contain
more than 15 percent nickel plated material.
-128-
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Old rolled brass shall consist of old pieces of yellow sheet
brass and yellow light tubing brass, free from solder, tinned, and
nickel-plated material, iron, paint and corrosion, rod brass and
condenser tubes.
New brass clippings shall consist of the cuttings of new
unleaded yellow brass sheet or plate, to be clean and free of foreign
substances, and not to contain more than 10 percent of clean brass
punchings under one-fourth inch. To be free of Muntz metal and
naval brass.
Brass shell cases without primers shall consist of clean-
fired 70/30 brass shell cases free of primers and any other foreign
material.
Brass shell cases with primers shall consist of clean-
fired 70/30 brass shell cases containing the brass primers and
which contain no other foreign material.
Brass small arms and rifle shells, clean-fired shall consist
of clean-fired 70/30 brass shells free of bullets, iron, and any
other foreign material.
Brass small arms and rifle shells, clean muffled (popped)
shall consist of clean muffled (popped) 70/30 brass shells free
of bullets, iron, and any other foreign material.
Yellow brass primer shall consist of clean yellow brass
primers, burnt or unburnt. Free of iron, excessive dirt, corrosion,
and any other foreign material.
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Brass pipe shall consist of brass pipe free of plated and
soldered materials or pipes with cast brass connections. To be
sound, clean pipes free of sediment and condenser tubes.
Yellow brass rod turnings shall consist of strictly rod
turnings, free of aluminum, manganese, composition, and Tobin
and Muntz metal turnings; not to contain over 3 percent free iron,
oil, or other moisture; to be free of grindings and babbitts; to
contain not more than 0.30 percent tin and not more than 0.15
percent alloyed iron.
New yellow brass rod ends shall consist of new, clean
rod ends from free-turning brass rods or forging rods, not to
contain more than 0.30 percent tin and not more than 0.15
percent alloyed iron. To be free of Muntz metal and naval brass
or any other alloys. To be in pieces not larger than 12 inches
and free of foreign matter.
Yellow brass turnings shall consist of yellow brass turnings,
free of aluminum, manganese, and composition turnings; not to
contain over 3 percent of free iron, oil, or other moisture; to
be free of grindings and babbitts. To avoid dispute, to be sold
subject to sample or analysis.
Mixed unsweated auto radiators shall consist of mixed
automobile radiators, to be free of aluminum radiators, and iron
finned radiators. All radiators to be subject to deduction of
actual iron. The tonnage specification should cover the gross
weight of the radiators, unless otherwise specified.
Admiralty brass condenser tubes shall consist of clean
sound Admiralty condenser tubing which may be plated or unplated,
free of nickel alloy, aluminum alloy, and corroded material.
-130-
-------
Aluminum brass condenser tubes shall consist of clean
sound condenser tubing which, may be plated or unplated, free of
ncikel alloy, and corroded material.
Muntz metal tubes shall consist of clean sound Muntz
metal tubing which may be plated or unplated, free of nickel
alloy, aluminum alloy, and corroded material.
Plated rolled brass shall consist of plated brass sheet,
pipe, tubing and reflectors, free of soldered, tinned, corroded,
and aluminum-painted material, Muntz metal and Admiralty tubing,
and material with cast brass connections.
Manganese bronze solids shall have a copper content of
not less than 55 percent, a lead content of not more than 1 per-
cent, and shall be free of aluminum bronze and silicon bronze.
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