United States
Environmental Protection
Agency
Office of Air Quality
Planning and Standards
Research Triangle Park NC 27711
EPA-450/3-84-01*f
December 1984
A.r
Ei
Review of National
Emission Standards
for Mercury
n
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EPA-450/3-84-014
Review of
National Emission Standards
for Mercury
Emission Standards and Engineering Division
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Air and Radiation
Office of Air Quality Planning and Standards
Research Triangle Park, NC 27711
December 1984
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This report has been reviewed by the Emission Standards and Engineering Division of the Office of Air
Quality Planning and Standards, EPA, and approved for publication. Mention of trade names or commercial
products is not intended to constitute endorsement or recommendation for use Copies of this report are
available through the Library Services Office (MD-35), U.S. Environmental Protection Agency, Research
Triangle Park, N.C. 27711, or from National Technical Information Services, 5285 Port Royal Road,
Springfield, Virginia 221 61.
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ENVIRONMENTAL PROTECTION AGENCY
Background Information
for Review of the National Emission
Standards for Mercury
'Jack R. Farmer
Director, Emission Standards and Engineering Division
U. S. Environmental Protection Agency
Research Triangle Park, NC 27711
1. The Federal Register notice summarizes information gathered during
the review, proposes the addition of monitoring and reporting
requirements to the standard for mercury-cell chlor-alkali plants,
and proposes to allow the owner or operator of any affected facility
15 days to verify the validity of source test data prior to reporting
the results to the Administrator.
2. Copies of this document have been sent to the following Federal
Departments: Labor, Health and Human Services, Defense, Transportation,
Agriculture, Commerce, Interior, and Energy; the National Science
Foundation; the Council on Environmental Quality; State and Territorial
Air Pollution Program Administrators; EPA Regional Administrators; Local
Air Pollution Control Officials; Office of Management and Budget; and
other interested parties.
3. The comment period for review of this document is 75 days from date of
proposal in the Federal Register. Mr. Gilbert H. Wood may be contacted
at (919) 541-5578 regarding the date of the comment period.
4. For additional information, contact:
Gilbert H. Wood
Standards Development Branch (MD-13)
U. S. Environmental Protection Agency
Research Triangle Park, NC 27711
Telephone: (919) 541-5578
5. Copies of this document may be obtained from:
U. S. Environmental Protection Agency Library (MD-35)
Research Triangle Park, NC 27711
Telephone: (919) 541-2777
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
m
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TABLE OF CONTENTS
Section Title page
1 EXECUTIVE SUMMARY 1-1
1.1 Summary—Review of Source Categories Regulated by
Standard l-l
1.2 Summary—Investigation of Other Source Categories . . . 1-2
2 CURRENT STANDARDS 2-1
2.1 National Emission Standard 2-1
2.2 State Regulations 2-3
2.3 Reference for Chapter 2 2-3
3 MERCURY-CELL CHLOR-ALKALI PROCESS 3-1
3.1 Introduction 3-1
3.2 Process Description 3-3
3.3 Control Technology 3-5
3.4 Waste Disposal 3-9
3.5 Compliance Test Results 3-9
3.6 Compliance and Enforcement Aspects 3-10
3.7 Summary and Conclusions 3-14
3.8 References for Chapter 3 3-14
4 MERCURY ORE PROCESSING 4-1
4.1 Introduction 4-1
4.2 Process and Control Technology Descriptions 4-3
4.3 Compliance Test Results 4-5
4.4 Enforcement Aspects 4-5
4.5 Summary and Conclusions 4-5
4.6 References for Chapter 4 4-5
5 SLUDGE INCINERATION AND DRYING ... 5-1
5.1 Introduction 5-1
5.2 Process and Control Technology Descriptions 5-3
5.3 Compliance Test Results 5-6
5.4 Enforcement Aspects 5-7
5.5 Summary and Conclusions 5-7
5.6 References for Chapter 5 5-10
6 SOURCES NOT REGULATED BY THE STANDARD 6-1
6.1 Introduction 6-1
6.2 General . 6-1
6.3 Battery Manufacturing 6-4
6.4 Secondary Recovery of Mercury in Retorts 6-15
6.5 Summary and Conclusions 6-15
6.6 References for Chapter 6 6-17
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TABLE OF CONTENTS (CONTINUED)
App. A LIST OF EPA DESIGN, MAINTENANCE, AND HOUSEKEEPING
PRACTICES FOR CELL ROOMS OF MERCURY-CELL CHLOR-ALKALI
PLANTS A-l
LIST OF TABLES
Page
Table 3-1 Mercury-Cell Chlor-Alkali Plants in the United
States 3-2
Table 3-2 Compliance Test Results for Mercury Emissions from
Hydrogen Streams and End-Box Ventilation Streams at
Mercury-Cell Chlor-Alkali Plants 3-11
Table 4-1 Mercury Statistics for United States—1970 to 1982 . 4-2
Table 5-1 Size Distribution of Sludge Incineration Plants
Existing in 1973 and Constructed Between 1974 and
1981 5-2
Table 5-2 Mercury Emission Data for Sludge Incinerators .... 5-8
Table 6-1 United States Mercury Consumption in 1982 6-3
Table 6-2 Emission Source Parameters for the Integrated Mercury
Battery Manufacturing Facility 6-11
LIST OF FIGURES
Figure 3-1 Basic Flow Diagram for Mercury-Cell Chlor-Alkali
Operation 3-4
Figure 4-1 Flow Chart Showing Processing of Mercury Ore 4-4
Figure 5-1 Process Flow Diagram for Sludge Incineration in a
Multiple-Hearth Furnace 5-4
Figure 5-2 Process Flow Diagram for Sludge Incineration in a
Fluidized-Bed Furnace 5-5
Figure 6-1 General Flow Diagram for Mercuric Oxide Battery
Manufacture 6-6
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LIST OF FIGURES (CONTINUED
Page
Figure 6-2 Process Flow Diagram for Oxide Plant ......... 6-7
Figure 6-3 Process Flow Diagram for Main Plant ......... 6-8
Figure 6-4 Process Flow Diagram for Mercury Recovery Plant . . . 6-9
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1. EXECUTIVE SUMMARY
The national emission standard for mercury was promulgated by the
U.S. Environmental Protection Agency (EPA) on April 6, 1973. The standard
regulates those sources that have the potential to emit mercury in a
manner that could cause the daily mercury ambient concentration averaged
over 30 days to exceed 1.0 ug/m3 (4.37 xlO-7 gr/ft3), a guideline value
for adverse health effects. Initially the standard regulated mercury
air emissions from mercury-cell chlor-alkali plants and mercury ore
processing facilities. The standard was amended on October 14, 1975, to
also regulate mercury air emissions from sludge incineration and drying
plants. Testing procedures were amended in 1978 and 1982.
This study was made to assess the need to revise the standard for
mercury. Sources subject to the standard were identified, and information
was obtained on compliance and enforcement experience. Part of the
study was devoted to determining the need to include sources not covered
by the standard. Information was gathered from EPA files, literature
reviews, plant visits, telephone contacts with EPA region and State
personnel, and through information requests to industry personnel. The
following paragraphs summarize the findings of this study.
1.1 SUMMARY—REVIEW OF SOURCE CATEGORIES REGULATED BY STANDARD
1.1.1 Compliance Status
There are 24 mercury-cell chlor-alkali plants, 1 mercury ore processing
facility, and approximately 172 sludge incineration plants and 5 sludge
drying plants subject to the national emission standard for mercury.
All affected facilities are currently in compliance with the mercury
emission limits set by the standard. The mercury ore processing facility
and sludge incineration and drying plants meet the standard without
1-1
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specific controls for mercury, with emissions ranging from 0 to 1,234 g/d
total mercury (0 to 2.7 Ib/d). Mercury-cell chlor-alkali plants reduce
mercury air emissions using the following control techniques: cooling,
mist elimination, chemical absorption, activated carbon adsorption, and
molecular sieve adsorption. All mercury-cell chlor-alkali plants have
elected to demonstrate compliance with approved EPA design, maintenance,
and housekeeping practices for cell rooms in lieu of testing cell room
emissions. Compliance tests conducted since 1973 show that for several
facilities the combined mercury emissions from the hydrogen and end-box
ventilation systems approach the emission limit set for these gas streams.
1.1.2 Enforcement Aspects
State and EPA regional personnel responsible for enforcing the
mercury standard have not encountered any significant enforcement problems.
Presently there are no monitoring or reporting requirements for chlor-
alkali companies in the standard. Because of the importance of cell-room
housekeeping and maintenance practices to controlling emissions from
"mercury-cell chlor-alkali plants and because some plants are approaching
the limit set for the combined hydrogen gas and end-box ventilation
streams, there is a need for monitoring requirements for housekeeping
and maintenance practices and for control equipment performance. This
is consistent with comments made by EPA regional and State enforcement
personnel.
1.2 SUMMARY—INVESTIGATION OF OTHER SOURCE CATEGORIES
Mercury is emitted to the atmosphere from a number of sources in
addition to those regulated by the national emission standard. Sources
include power plants, nonferrous smelters, solid waste incinerators,
by-product mercury from gold mining, battery manufacturing, mercury
vapor lamp manufacturing, instrument manufacturing, paint manufacturing,
manufacture of mercury compounds, laboratory use of mercury, use of
dental amalgams, and secondary mercury recovery. Only battery manufacturin
and secondary mercury recovery were selected for investigation as candidate
for regulation based on the probable magnitude of their air emissions.
1-2
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1.2.1 Mercury Emissions Potential From Battery Manufacturing
Mercury in the form of zinc amalgam, mercuric oxide, mercuric
chloride, or mercurous chloride is a component of most primary batteries
and some storage batteries. Information on facilities manufacturing
mercuric oxide-zinc, mercuric oxide-cadmium, alkaline-manganese, and
Leclanche carbon-zinc batteries was obtained in this study. This informa-
tion indicates that one large integrated mercuric oxide battery manufacturi
facility (battery manufacture, oxide manufacture, and secondary recovery
at one site) and several large alkaline-manganese battery manufacturing
facilities have the potential for significant mercury emissions.
Ambient mercury levels greater than 1 ug/m3 (4.37 xlO-7 gr/ft3)
have been measured over a 6- to 9-hour period at points on the plant
perimeter of an integrated mercuric oxide battery manufacturing facility.
Atmospheric dispersion modeling, however, showed that the maximum 30-day
average ambient mercury concentrations would not approach the health
effects guideline. Mercury vapor emissions at this facility are largely
uncontrolled, while particulate mercury emissions are generally well
controlled by baghouses and other particulate filters.
A large alkaline-manganese battery manufacturing facility may use
up to 910 kg/d (2,000 Ib/d) of mercury. Mercury vapor emissions are
uncontrolled at these plants. Particulate mercury emissions can be
controlled by baghouses. Industry estimates suggest that mercury air
emissions may reach 800 g/d (1.8 Ib/d) from some of these plants.
Atmospheric dispersion modeling indicated that the health effects guideline
would not be exceeded at these facilities.
1.2.2 Mercury Emissions Potential From Secondary Mercury Recovery
Large secondary mercury recovery retorting operations have the
potential for significant uncontrolled mercury vapor emissions because
of the amount of mercury recovered. Information on three mercury recovery
facilities was obtained in this study. Emissions are controlled by a
water spray at the first facility, a water scrubber and charcoal filter
in series on an experimental basis at the second facility, and a condenser
at the third facility. Estimated emissions are not large enough to
cause the ambient concentration guideline to be exceeded.
1-3
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at the third facility. Estimated emissions are not large enough to
cause the ambient concentration guideline to be exceeded.
1-4
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2. CURRENT STANDARDS
2.1 NATIONAL EMISSION STANDARD
2.1.1 Affected Facilities
The national emission standard for mercury was developed to regulate
sources that have the potential to emit mercury in a manner that could
cause the inhalation health effects limit of 1.0 ug/m3 (4.37 xlO-7 gr/ft3)
of mercury (daily concentration averaged over 30 days) to be exceeded.
Based on this criterion, the national emission standard for mercury has
been applied to stationary sources that process mercury ore to recover
mercury, use mercury chlor-alkali cells to produce chlorine gas and
alkali metal hydroxide, and incinerate or dry wastewater treatment plant
sludge.
2.1-2 Controlled Pollutant and Emission Levels
Allowable emission limits for the affected facilities were derived
from the ambient concentration guideline by using atmospheric dispersion
models. The national emission standard limits mercury emissions to the
atmosphere as follows:
1. Mercury ore processing facility—2,300 g (5 Ib) per 24-hour period
2. Mercury cell chlor-alkali plant--2,300 g (5 Ib) per 24-hour period
and
3. Sludge incineration plants, sludge drying plants, or combination
of these that process wastewater treatment plant sludges—3,200 g (7 Ib)
of mercury per 24-hour period.
"Mercury" means the element mercury, excluding any associated
elements, and includes mercury in particulates, vapors, aerosols, and
compounds.
2-1
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2.1.3 Testing Requirements
Performance tests to verify compliance with the mercury standard
must be conducted within 90 days of the effective date of the standard
for existing sources and of the initial startup date for new sources.
The following EPA reference methods are used to determine compliance:
1. Method 101--Determination of Particulate and Gaseous Mercury
Emissions from Chlor-Alkali Plants—Air Streams;
2. Method 101A--Determination of Particulate and Gaseous Mercury
Emissions from Sewage Sludge Incinerators;
3. Method 102—Determination of Particulate and Gaseous Mercury
Emissions from Chlor-Alkali Plants—Hydrogen Streams; and
4. Method 105—Method for Determination of Mercury in Wastewater
Treatment Plant Sewage Sludges.
Owners or operators of mercury chlor-alkali cells may test cell
room emissions by passing all air in forced gas streams through stacks
suitable for testing. Alternatively, ventilation emissions of 1,300 g/d
(2.8 Ib/d) of mercury may be assumed if compliance with approved design,
maintenance, and housekeeping practices is demonstrated. This alternative
effectively results in an emission limit of 1,000 g/d (2.2 Ib/d) of
mercury for the hydrogen and end-box ventilation streams. Stack sampling
requirements for mercury recovery retorts at chlor-alkali plants are not
specified in the standard.
Owners or operators of sludge incineration and drying plants may
elect to conduct stack tests using Method 101A. Alternatively, they may
demonstrate compliance by determining the mercury concentration of the
sludge using Method 105. Mercury emissions are estimated using the
equation: EH = 1 xlO-3 cQ
where EH = mercury emissions, g/d;
c = mercury concentration in sludge on a dry solids basis, ug/g;
and Q = sludge charging rate, kg/d.
2.1.4 Monitoring Requirements
No monitoring requirements for mercury ore processing facilities or
mercury cell chlor-alkali plants are included in the national emission
standard. A monitoring requirement is included for sludge incineration
and drying plants. Sources that exceed 1,600 g/d (3.5 Ib/d) of mercury
2-2
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emissions must monitor and report emissions at intervals of at least
once per year.
2.2 STATE REGULATIONS
State air regulations listed in the Environment Reporter were
compared with the national emission standard for mercury to identify
differences.1 Of the 50 States, District of Columbia, and Puerto Rico,
28 do not have specific mercury regulations. Twenty States and Puerto
Rico have adopted the mercury national emission standard by reference or
have regulations identical to the national standard. Two States, Colorado
and Oregon, apply the 2,300 g/d (5 Ib/d) limit to all sources using
mercury. The State of Wisconsin has an ambient air standard for mercury
of 1 ug/m3 (4.37 xlO-7 gr/ft3) on a 30-day average for all mercury
emission sources in addition to an emission limit of 2,300 g/d (5 Ib/d)
for chlor-alkali plants and ore processing facilities.
2.3 REFERENCE FOR CHAPTER 2
1. Memorandum, M. Sauer, MRI, to N. Georgieff, EPA. March 25, 1983.
State mercury air emission regulations. Docket No. A-82-41,
Document No. (II-B-7).
2-3
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3. MERCURY-CELL CHLOR-ALKALI PROCESS
3.1 INTRODUCTION
Three types of electrolytic cells are used in the U.S. to produce
chlorine and caustic: the mercury cell, the diaphragm cell, and the
membrane cell. Mercury is emitted to the atmosphere only from the
mercury-cell process.
There are 32 chlorine producing companies, with 60 chlor-alkali
plants, in the U.S. Mercury-cell technology is used at 24 plants,
diaphragm-cell technology is used at 34 plants, and membrane-cell techno!og:
is used at two plants.1 Mercury-cell chlor-alkali plants in the U.S.
are listed in Table 3-1 along with the year built and type of cells used
at each plant.
Average chlorine production by all processes increased only slightly
from 25,855 Mg/d (28,500 tons/d) in 1973 to 26,243 Mg/d (28,928 tons/d)
in 1981.2 Total installed chlorine capacity increased from 26,892 Mg/d
(29,643 tons/d) in 1973 to 35,835 Mg/d (39,502 tons/d) in 1981.2 The
percent of total installed chlorine capacity using mercury cells decreased
from 25 percent in 1973 to 19 percent in 1982.3 The chlor-alkali industry
used 6,516 flasks (225 Mg [248 tons]) of mercury in 1982.
It is probable that no new mercury-cell chlor-alkali plants will be
built in the U.S. in the future.4 No new plants have been built since
the national emission standard was promulgated in 1973. There has been
some new construction in the chlor-alkali industry but not in the mercury-
cell segment. In the future, membrane-cell technology may take precedence
over both the mercury-cell and diaphragm-cell technologies.4
3-1
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TABLE 3-1. MERCURY-CELL CHLOR-ALKALI PLANTS IN THE UNITED STATES5
Company/location
Year built Cell type
Convent Chemical Company
(Subsidary of B. F. Goodrich)
Calvert City, Ky.
Diamond Shamrock Corp. ,
Deer Park, Tex.
Delaware City, Del.b
Mobile, Ala. .
Muscle Shoals, Ala.
Georgia Pacific Company '
Bellingham, Wash.
Linden Chemicals & Plastics, Inc.
Acme, N.C. .
Ashtabula, Ohio0
Brunswick, Ga.
Linden, N.J.
Moundsville, W. Va.a
Orrington, Maine
Syracuse, N.Y.
Monsanto Company
Sauget, 111. .
Occidental Chemical
Corporation/IMC Corporation
(Hooker-Sobin Joint Venture)
Niagara Falls, N.Y.
01 in Corporation
Augusta, Ga.
Charleston, Tenn.
Mclntosh, Ala.
Niagara Falls, N.Y.
PPG Industries,
Lake Charles, La.
New Marti nsvi lie, W. Va.
Stauffer Chemical Company
LeMoyne, Ala.
St. Gabriel, La.
Vulcan Materials Company,
Chemicals Division
Port Edwards, Wis.
1966 De Nora 24H5
1938 De Nora 18 SGL;
(also diaphragm cell)
1965 De Nora 18x4
1964 De Nora 18x4
1952 De Nora 24x2M
1965 De Nora 18x4
1963 Solvay V-200
1963 01 in E11F
1957 Solvay V-100
1956 BASF-Krebs (1969);
Krebs (1963)
1953 Solvay S60
1967 De Nora 24H5
1927 Solvay S60 (1953);
(also diaphragm cell)
1922 De Nora 18x6
1971 Uhde 20 sq. m
1965 01 in E11F
1962 01 in E11F, E812
1952 01 in E8
1897 01 in E11F (1960)
1947 De Nora 48H5 (1969);
(also diaphragm cell)
1943 Uhde 20 sq. m (1958);
(also diaphragm cell)
1965 De Nora 22x5
1970 Uhde 30 sq. m
1967 De Nora 24H5
Electrolytic plant producing caustic soda, chlorine, and hydrogen from
.brine.
Electrolytic plant producing caustic soda, caustic potash, chlorine, and
hydrogen from brine.
jPulp mill.
Electrolytic plant producing caustic potash, chlorine, and hydrogen from
brine.
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3.2 PROCESS DESCRIPTION
3.2.1 Mercury-Cell Process
A flow diagram for the production of chlorine and caustic using
mercury cells is given in Figure 3-1. Purified brine is fed from the
main brine treatment section through the inlet end box to the electrolyzer,
where it flows between a stationary graphite or metal anode and a flowing
mercury cathode. The spent brine is recycled from the electrolyzer to
the main brine treatment section through a dechlorination step. Chlorine
gas is formed at the anode of the electrolyzer and is collected for
further treatment. The gas is cooled, dried by scrubbing with concentrated
sulfuric acid, and compressed. The dry chlorine gas may be used directly
or may be liquified.6
The sodium is collected at the cathode of the electrolyzer, forming
an amalgam. The sodium amalgam flows from the electrolyzer through the
outlet end box to the decomposer, where it is the anode to a short-circuite
graphite or metal cathode in an electrolyte of sodium hydroxide solution.
Water is fed to the decomposer and reacts with the sodium amalgam to
produce elemental mercury, sodium hydroxide solution, and by-product
hydrogen gas.
The stripped mercury is returned to the cell. The caustic soda
solution generally leaves the decomposer at a concentration of 50 percent
sodium hydroxide by weight. This solution is usually filtered to remove
impurities. The filtered caustic solution may be further concentrated
by evaporation. The by-product hydrogen gas from the decomposer may be
vented to the atmosphere, burned as a fuel, or used as a feed material
in other processes.6
The inlet end box is a receptacle that is placed on the inlet end
of the electroylzer to provide a convenient connection for the stripped
mercury as it returns from the decomposer to the electrolyzer. Also, it
keeps the incoming mercury covered with an aqueous layer. The outlet
end box is a receptacle that is placed on the outlet of the electrolyzer
to provide a convenient means for keeping the sodium amalgam covered
with an aqueous layer and for the removal of thick mercury "butter" that
is formed by impurities.6,7
3-3
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BASIC TREATMENT CHEMICALS
(SODA ASH, CAUSTIC LIME,
ACID, CaCL2, ETC.)
SOLID
FEED
CHLORINE
OTHER
I
1
BRINE
DECHLORINATOR
SPENT BRINE
TREATED
MAIN BRINE
SATURATION,
PURIFICATION, AND
FILTRATION
BR|NE
INLET
END-BOX-
END-BOX
VENTILATION SYSTEM
STRIPPED
AMALGAM
END-BOX
VENTILATION SYSTEM
1
ELECTROLY2ER
WATER COLLECTION
SYSTEM
PRODUCT
CHLORINE
i
COOLING,
DRYING,
LIQUEFACTION
• OUTLET END-BOX
^ END-BOX
VENTILATION SYSTEM
END-BOX
' VENTILATION SYSTEM
Hg PUMP
DECOMPOSER
(DENUDER)
AMALGAM
CAUSTIC SODA
SOLUTION
HYDRQGE^
GAS
BYPRODUCT
FILTRAT.ON.
CONCENTRA-
-TION, AND
MERCURY
RECOVERY
PROC
•CAUS
SODA
Figure 3-1. Basic flow diagram for mercury-cell chlor-alkali operation,
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The end-box ventilation system applies suction to the end boxes,
the sumps for the mercury pumps, and the water collection system to
reduce mercury vapor emissions to the cell room. A large quantity of
ventilation air is used to keep the mercury vapor concentration of the
cell room at allowable levels.6 Typical volumes for cell room ventilation
air range from 94 to 425 standard mVs (200,000 to 900,000 scfm).9
Several chlor-alkali companies recover mercury from sludges by
using retorts on-site. Sludges are loaded into the retort and indirectly
heated to high temperature to vaporize the mercury. The mercury vapor
is cooled in a water-cooled condenser outside the retort and is recovered.
Mercury recovery retorts are typically operated on an intermittent
basis, one to several times per month.10,11 Secondary recovery of
mercury is discussed further in Chapter 6.
3.2.2 Mercury Emission Sources
The major sources of mercury emissions to the atmosphere are:
(1) the hydrogen by-product stream, (2) end-box ventilation system, and
(3) cell room ventilation air. The hydrogen by-product stream leaving
the decomposer is saturated with mercury vapor and may carry mercury in
the form of fine droplets. The amount of mercury emitted by the end-box
ventilation system depends on the degree of mercury saturation and the
volumetric flow rate.
Mercury enters the cell room air from a number of sources, which
include: (1) end-box sampling, (2) removal of mercury butter from end
boxes, (2) cell maintenance and rebuilding operations, (4) other maintenanc
work that exposes internal surfaces of pipes and equipment, (5) accidental
mercury spills, (6) leaks from cells and mercury pumps, and (7) cell
failure and other unusual circumstances.12
3.3 CONTROL TECHNOLOGY
Control techniques used to reduce mercury emissions from the hydrogen
stream and end-box ventilation stream are: (1) cooling, (2) mist elimina-
tion, (3) chemical absorption, (4) activated carbon adsorption, and
(5) molecular sieve adsorption. These are described briefly in this
section. For more detailed descriptions, see References 13 and 14.
Also discussed in this section are housekeeping practices for the cell
room and the use of nonmercury cell technology.
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No new control technology has been developed in the chlor-alkali
industry since the national emission standard was promulgated in 1973.9
3.3.1 Cooling
Cooling may be used as the primary control technique for the hydrogen
stream or the end-box stream, or it may precede other control techniques.
Hydrogen leaves the decomposer at 93° to 127°C (200° to 260°F) and
passes into a primary cooler. Water at ambient temperature is typically
used in a shell-and-tube heat exchanger to cool the stream to 32° to
43°C (90° to 110°F). A mercury knockout drum following the cooler
separates the condensed mercury from the hydrogen stream. An additional
direct or indirect cooler using chilled water or brine may further cool
the hydrogen stream to 3° to 13°C (37° to 55°F). Direct-contact coolers
using chilled water or brine require water treatment systems.
The end-box ventilation air can be cooled similarly to the hydrogen
stream. Direct-contact coolers are used more than indirect coolers due
to the presence of mercuric chloride particulate matter in the gas
stream.
3.3.2 Mist Elimination
The cooled gas stream is typically passed through a mist eliminator.
Two basic types of mist eliminators remove mercury mist from gas streams.
One consists of a fiber pad enclosed in screens, and the other uses a
converging-diverging nozzle. Trapped particles are removed from the
mist eliminators by spray washing.
3.3.3 Chemical Absorption
Scrubbers using depleted brine or a sodium hypochlorite (NaOCl)
solution have been used for mercury removal from hydrogen and end-box
ventilation gas streams. In the depleted brine scrubbing system, the
spent brine discharged from the cell is used as the scrubbing medium in
a sieve plate tower or a packed-bed scrubber. Mercury vapor and mist
form soluble mercury complexes upon contact with the scrubbing solution.
The scrubbing solution is returned to the mercury chlor-alkali cell
where the mercury is recovered by electrolysis.
3.3.4 Activated Carbon Adsorption
Sulfur- and iodine-impregnated carbon adsorption have been used by
several companies to reduce the mercury concentration in the hydrogen
3-6
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gas stream. Prior to carbon adsorption, primary and secondary cooling
followed by mist elimination have usually removed about 90 percent of
the mercury content of the hydrogen stream.15 The mercury vapor remaining
in the stream is adsorbed by the carbon and chemically reacts with the
sulfur or iodine to form mercury compounds. Several adsorber beds may
be placed in series. A vendor has reported typical outlet concentrations
below 50 parts per billion by volume (ppbv) that may approach 1 ppbv.16
3.3.5 Molecular Sieve Adsorption
Mercury vapor can be removed from the hydrogen gas stream or end-box
ventilation stream by adsorption on a proprietary molecular sieve
adsorbent.9 The PuraSiv-Hg system developed by Union Carbide Corporation
is used by five chlor-alkali companies in the U.S.9 Following cooling
and mist elimination, the hydrogen gas stream passes through one of two
adsorption beds. Eighty to ninety percent of the treated hydrogen gas
passes out of the system to disposal or usage. The remainder is heated
to 316°C (600°F) and used as a recycle-regeneration stream for removing
entrapped mercury from the second adsorber bed. After passing through
the second adsorption bed, this gas stream is cooled and is combined
with the incoming mercury-laden hydrogen stream from the primary cooling
section. At any time, one bed is undergoing adsorption, and the other
is undergoing regeneration. The concentration of mercury in the effluent
has been guaranteed to be lower than 60 ppbv on average.17 Some operational
problems have been reported with molecular sieves currently in operation.
The most common difficulties involved excessive moisture buildup;
however, to date all problems have been corrected.9
®
Union Carbide no longer supplies the PuraSiv-Hg process to control
mercury emissions from chlor-alkali plants. However, Union Carbide
could provide a license to its patents and technology.18
3.3.6 Housekeeping Practices
The mercury national emission standard allows chlor-alkali companies
the option of either modifying the cell room so stack sampling can be
used or complying with approved maintenance and housekeeping practices
that will minimize mercury emissions from the cell room. All chlor-alkali
companies have opted to follow the EPA recommended housekeeping practices
in lieu of stack testing. An emission limit of 1,300 g/d (2.8 Ib/d) of
3-7
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total mercury is assigned to the cell room when the housekeeping practices
are followed. The housekeeping practices recommended by the EPA are listed
in Appendix A of this document.19
3.3.7 Nonmercury-Cell Technology
Mercury emissions from chlor-alkali operations can be eliminated by
switching to a nonmercury technology, either the diaphragm- or membrane-eel
technology. In the diaphragm cell, the electrolytic reaction products
are separated by an asbestos diaphragm. Chlorine is generated at the
anode on one side of the diaphragm, and caustic soda and hydrogen gas
are produced at the cathode on the other side. Several disadvantages of
the diaphragm-cell process preclude it from being a universal substitute
for the mercury-cell process. A lower grade caustic (i.e., greater
sodium chloride content) is produced by the diaphragm-cell process, and
the caustic at about 11 percent by weight must be evaporated to obtain a
50 percent solution.20 A second disadvantage is that diaphragm-cell
plants may discharge asbestos in their wastewater streams.
The membrane cell process is free from both mercury and asbestos
contaminants. In the membrane cell, a synthetic cation exchange membrane
separates the electrolytic reaction products. As in the standard diaphragm
cell, chlorine gas is generated at the anode on one side of the membrane,
and caustic soda and hydrogen gas are produced at the cathode on the
other side. The membrane allows passage of only sodium ions from the
anode to cathode compartment. This results in production of caustic
that is purer and more concentrated than that from standard diaphragm
cells.21 The caustic solution produced by membrane cells can be up to
25 to 30 percent caustic by weight.22 This caustic solution must also
be evaporated to obtain a 50 percent solution.
Japan is presently committed to convert all mercury-cell chlor-alkali
operations to membrane-cell operations. In 1979, Japanese government
committees judged that membrane-cell technology had reached a technical
level suitable for commercial application.23,24 There are presently two
commercial and two pilot chlor-alkali plants employing membrane cells
operating in the U.S.25,26
Most chlor-alkali companies employing mercury-cell technology have
considered using the membrane-cell technology. However, the current
3-8
-------
economic conditions of the chlor-alkali industry and the cost of switching
to membrane cells are a major impediment to replacement at this time.27
3.4 WASTE DISPOSAL
Because of its vaporization properties, mercury can be emitted to
the atmosphere from mercury contaminated waste products. Techniques
used to remove mercury from wastewater and solid waste products are
discussed below.
3.4.1 Wastewater
Potential sources of mercury-laden wastewater discharges at a
mercury-cell chlor-alkali plant include: (1) cell room floor washing,
(2) caustic filter backwash, (3) cell end-box washing, (4) brine purges
and filter washing, (5) mercury pump seal water, and (6) direct-contact
cooling of the hydrogen stream.9
Wastewater is typically treated at a central treatment plant located
on-site. A commonly used treatment method is precipitation with sodium
sulfide or sodium hydrosulfide followed by filtration.
Mercury-cell chlor-alkali plants are subject to effluent limitations
guidelines and new source performance standards for the mercury content
of wastewater effluents.27
3.4.2 Solid Waste
Potential sources of mercury-contaminated solid waste at a chlor-alkal
plant include: (1) wastewater treatment solids, (2) mercury-contaminated
equipment, (3) brine purification solids, (4) caustic filter backwash,
(5) spent carbon from carbon bed adsorbers, and (6) retort ash.9
Mercury may be recovered from certain sludges in retorts as described
previously. Sludges and solid wastes generated in the process are
typically disposed in a hazardous waste landfill.
3.5 COMPLIANCE TEST RESULTS
All operating chlor-alkali plants are in compliance with the national
emission standard for mercury according to the EPA Compliance Data
System and EPA regional and State contacts.28 Following the promulgation
of the standard, all plants were required to demonstrate compliance.
Test results for the hydrogen gas stream and the end-box ventilation
system are given in Table 3-2. Mercury emissions from the hydrogen gas
3-9
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stream ranged from 1 to 891 g/d (0.002 to 2.0 lb/d).9 The lower mercury
emission levels were generally measured on hydrogen streams controlled
by molecular sieve or carbon adsorption control systems.9 (Performance
problems encountered with these and other control devices are discussed
in the next section.) Most mercury emission levels above 400 g/d (0.88 lb/
were measured on hydrogen streams controlled by cooling systems alone.9
For the end-box ventilation stream, mercury emissions generally ranged
from 1 to 428 g/d (0.002 to 0.94 lb/d).9 Test methods used followed
EPA Method 101 for the end-box ventilation streams and Method 102 for
hydrogen streams. No data are available for cell room emissions because
all mercury-cell chlor-alkali companies have opted to follow the EPA
cell room housekeeping practices instead of testing cell room emissions.9
3.6 COMPLIANCE AND ENFORCEMENT ASPECTS
3.6.1 Compliance Problems
Compliance problems noted by several companies include cell room
floor maintenance, training of operation and maintenance personnel, and
control system failures. The most common control system failures occur
in the hydrogen cooling systems. Duplicate systems are usually installed
as backups to correct this problem.9 These backup systems have become
increasingly important in plants where molecular sieves are used. This
is due to regeneration problems that arise in the molecular sieves when
the primary hydrogen coolers are fouled or fail. No other control
problems were reported by industry.9
Information on mercury-cell chlor-alkali plants was obtained from
States, EPA regions, and information requests to the industry. Each
contact was asked to express his or her views on the appropriateness of
the current standard. Two companies noted that the standard is reasonable
and should not be changed.29,30 No chlor-alkali company suggested any
changes to the mercury emission level or to the EPA test methods. One
company noted that the cell room design, maintenance, and housekeeping
practices are achievable, and EPA's figure of 1,300 g/d (2.9 Ib/d) of
mercury emissions assumed for the cell room when these practices are
followed is reasonable.31 The EPA design, maintenance, and housekeeping
practices for the cell room are listed in Appendix A. One company had
the following comments on the housekeeping practices for the cell room:32
3-10
-------
TABLE 3-2. COMPLIANCE TEST RESULTS FOR MERCURY EMISSIONS FROM
HYDROGEN STREAMS AND END-BOX VENTILATION STREAMS AT MERCURY-CELL
CHLOR-ALKALI PLANTS 9
Plant
code3
A
B
C
D
E
F
G
H
I
J
K
I
M
N
0
P
Q
R
C12
produc-
tion
rate,
tons/d
350
300
120
400
235
110
300
450
225
220
100
135
125
311
366
314
700
208
Control devices'"
H2
HE,
SP,
HE,
CO,
CB
CO,
SP,
CO,
KO,
CO,
KO, CP,
HE, ME,
CB
0, CP,
CP, CP
CH
CP, CH
CB
CO, CO, D
CO, ME, CP
CO,
CO,
CO,
CO,
o,
SP,
CB
CO,
CO,
CP,
CP,
CH,
CO,
CH,
CO,
cc,
CO,
CP,
CO,
CP, CH, D
CP, MS
R
SP, B, CO,
MS
CO, CH, OR,
CO, S, CB
CO, CP,
CP, CP,
CO, CO,
CH, MS
CP, CO,
CB
CO, CO,
F. CO, CO
0, MS,
CB
s, s
End-Box
S, D, B
CO, CP,
CH, 0
None
None
CO, CO, 0
BS
NA
s, s
s, s
CO, SP, B,
MS
S
CO
S, CO
CH, 0
CO, CH, 0
CO
CO, SP, B
CO, CO, CO
Total Hg emissions
Date of
test
1974
1979
1974
1974
1977
1978
1980
1980
1981
1982
1979
1980
1981
1977
1981
1973
1974
1977
1975
1976
1976
1-973
1974
1979
1980
1973
1974
1982
1982
1981
1975
1973
H,
g/d
109
6
1
145
0.25
0.41
162
90
6
9
7
3
354
239
88
420
322
163
7
94
57
434
47
10
157
NA
50
295
48
592
264
NA
Ib/d
0.24
0.01
0.002
0.32
0.001
0.001
0.36
0.20
0.01
0.02
0.02
0.01
0.78
0.52
0.19
0.93
0.71
0.36
0.02
0.21
0.13
0.96
0.10
0.02
0.35
NA
0.11
0.65
0.11
1.31
0.58
NA
g^d
24&
160
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
1
48
16
165
114
23
1
<4
NA
201
NA
NA
550
16
428
235
390
236
44
90
End-box
Ib/d
0.54
0.35
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
0.003
0.11
0.04
0.36
0.25
0.05
0.002
<0.01
NA
0.44
NA
NA
1.21
0.036
0.94
0.52
0.86
0.52
0.10
0.20
(continued)
3-11
-------
TABLE 3-2. (continued)
C12
produc-
tion
r
Total HgD emissions
Plant rate, Control devices" Date of
code tons/d H2
S 225 CO, 0, CH, CP
CO, CH, D,
T 520
CP, SP, MS
U 220 CO, CP, S,
ME
End-box test
S, CB 1974
1976
1979
1980
1981
1982
1983
B, B, CO 1976
1978
CO, 8, S 1973
g/d
548
891
NA
610
864
NA
528
5
4
61
H,
lo/d
1.2
2.0
NA
1.3
1.9
NA
1.2
0.01
0.01
0.13
g/d
5
7
22
32
7
120
NA
52
63
2
End-box
Ib/d
0.01
0.02
0.05
0.07
0.02
0.26
NA
0.11
0.14
0.004
aPlant names are coded because certain companies requested confidential
^treatment of data.
HTest data using EPA Method 102 for H2 stream and EPA Method 101 for end-box ventilation stream.
"NA" indicates that no test data were available.
Code for control devices:
B = Blower
BS = Brine scrubber
CB = Carbon bed
CC = Centrifugal collector
CH = Chillers
CO = Coolers
CP = Compressors
D = Denrister
OC = Dust collector
OR = Driers
F = Filter
HE » Heat exchanger
KO = Knockout drum
ME = Mist eliminator
MS = Molecular Sieve
R = Refrigeration
S = Scrubber
SP = Separator
3-12
-------
1. Item 12 should be modified to allow the reuse of hydrogen
seal pot water, compressor seal water, and hydrogen cooler condensate
instead of requiring it to be treated. Additionally, this water should
not be restricted from open trenches. The quantity of mercury in this
water is insignificant and exposure of this water to the atmosphere
poses no hazard for emitting mercury into the air.
2. Some decomposer pump sumps do not retain an aqueous layer on
top of the mercury since the decomposer vent gases are collected and
controlled by the end-box ventilation system. Other systems maintain an
aqueous layer over the mercury and some systems may have both methods of
control. Either method is adequate by itself, therefore, items 8 and 9
should be modified to allow either method to be used instead of both.
3.6.2 Enforcement Aspects
Mercury-cell chlor-alkali plants are located in 16 States. Thirteen
of these States have been granted authority to enforce the national
emission standards for hazardous air pollutants. Enforcement personnel
representing 11 States and 6 EPA regions were contacted to obtain informa-
tion on enforcement aspects of the mercury standard. No significant
enforcement problems have been encountered. However, enforcement personnel
did comment on several aspects of the standard. These comments are
summarized below.
As discussed in Chapter 2, there are no monitoring or reporting
requirements in the standard for chlor-alkali companies. The EPA Region II
office requires that chlor-alkali companies submit a semiannual summary
of inspection and maintenance records. State personnel in this region
noted that the reporting requirement aids in the enforcement of the
standard. It provides them with baseline data to evaluate plant performanc
and allows them to spot problems as they develop.31 An EPA Region III
representative believes the reporting requirement is more efficient than
conducting full plant inspections.33 One company contacted in this
region noted that the requirement does not affect controls and procedures
used to comply with the standard but does create additional paperwork.31
Enforcement personnel in five States and two regions believed that
some type of specific monitoring and reporting requirements should be
included in the standard to ensure compliance.31,33-38 One State
3-13
-------
representative suggested that monitoring and reporting requirements be
instituted only for those facilities encountering compliance problems.39
A State agency contacted did not feel monitoring and reporting require-
ments were necessary but did believe that sources should be tested every
3 to 5 years to demonstrate compliance.40 Other States and EPA regional
personnel contacted in this study did not comment on the need for
monitoring and reporting requirements.
Two enforcement personnel noted that the cell room housekeeping
practices portion of the standard is a subjective evaluation method
because it is not quantifiable.36,37,41 Additionally, one of these
individuals recommended that the EPA should test the cell room vent air
and develop a specific numerical emission limit.36
3.7 SUMMARY AND CONCLUSIONS
Twenty-four mercury-cell chlor-alkali plants are operating in the
United States. All plants are in compliance with the national emission
standard for mercury. The EPA cell room housekeeping practices are
achievable.
No enforcement problems with the standard have been noted; however,
a number of State and EPA regional personnel believe that reporting
requirements should be added to the standard.
3.8 REFERENCES FOR CHAPTER 3
1. Chlorine Institute. North American Chior-Alkali Industry Plants
and Production Data Book. Pamphlet 10. New York, N.Y.
January 1983. pp. 1 and 2, 16. Docket No. A-82-41, Document
No. (II-I-28).
2. Reference 1, p. 12. (II-I-28).
3. Reference 1, p. 15. (II-I-28).
4. Telecon. Sauer, M., MRI, with Laubusch, E., Chlorine Institute.
January 18, 1983. Future chlor-alkali production. (II-E-53).
5. Reference 1, pp. 1 and 2. (II-I-28).
6. Reference 7, pp. 3-20 to 3-22. (II-A-2).
7. Kirk-Othmer Encyclopedia of Chemical Technology. Third Edition.
Volume I. New York, John Wiley & Sons, Inc. 1978. p. 811.
(II-I-13).
3-14
-------
8. U.S. Environmental Protection Agency. Control Techniques for
Mercury Emissions from Extraction and Chlor-Alkali Plants. AP-118.
Research Triangle Park, N.C. February 1973. p. 3-21. (II-A-2).
9. Memorandum from Sauer, M., MRI, to Project File 7703-L. June 28,
1983. Summary of Information Obtained for Mercury-Cell Chlor-Alkali
Plants. (II-B-10).
10. Letter and attachments from Taylor, W., EPA Region VI, to
Georgieff, N. , EPA:ISB. August 24, 1982. Information regarding
mercury emission sources, including retort at PPG Industries, Lake
Charles, La. (II-D-11).
11. Letter and attachments from Wu, J., EPA Region IV, to Georgieff, N.,
EPArlSB. 1982. Information on mercury emission sources, including
retort at LCP, Brunswick, Ga. (II-D-14).
12. Reference 7, p. 3-23. (II-A-2).
13. Reference 7, pp. 3-13, 3-24 to 3-30. (II-A-2).
14. U.S. Environmental Protection Agency. Molecular Sieve Mercury
Control Process in Chlor-Alkali Plants. EPA-600/2-76-014.
Research Triangle Park, N.C. January 1976. pp. 10-32. (II-A-7).
15. Reference 7, p. 3-29. (II-A-2).
16. Reference 15, p. 17. (II-A-7).
17. Reference 15, p. 12. (II-A-7).
18. Letter and attachments from Small, F., Union Carbide Corporation,
to Georgieff, N., EPA:ISB. December 18, 1981. Information on
PuraSiv-Hg process. (II-D-2).
19. U.S. Environmental Protection Agency. Background Information on
Development of National Emission Standards for Hazardous Air
Pollutants: Asbestos, Beryllium, and Mercury. PB-222802. Research
Triangle Park, N.C. March 1973. pp. 80-83. (II-A-3).
20. Reference 7, p. 3-24. (II-A-2).
21. Stinson, S. Electrolytic cell membrane development surges. Chemical
and Engineering News. March 15, 1982. p. 22. (II-I-23).
22. Memorandum from Sauer, M. , MRI, to N. Georgieff, EPA.-ISB. March 2,
1983. Report on site visit to Diamond Shamrock Corporation,
Delaware City, Delaware. (II-B-3).
23. Can MITI Keep Pushing Switch of Soda Process? Japan Chemical Week.
June 28, 1979. (II-I-15).
3-15
-------
24. Yoshizawa, S., Chairman. Caustic Soda Production Process Conversion
Promotion Committee, and Ion Exchange Membrane Process Technical
Evaluation Committee. Technical Evaluation for Ion Exchange Membrane
Process. Japan. June 13, 1979. p. 9. (II-I-14).
25. Georgieff, N. U.S. EPA. Monthly Report on Mercury NESHAP Review.
June 3, 1982. p. 4. (II-B-2).
26. Telcon. Georgieff, N., U.S. EPA with Esayian, M., Du Pont Chemical
Company. May 24, 1982. Information on membrane cell technology.
(II-E-2).
27. Bureau of National Affairs. Environment Reporter, Federal
Regulations, Volume 3, Effluent Guidelines and Standards for
Inorganic Chemicals. Subpart F—Chlor-alkali subcategory.
Washington, D.C. January 28, 1983. pp. 135:1301 to 135:1305.
(II-I-27).
28. Memorandum from Newton, D., and Sauer, M., MRI, to Georgieff, N.,
EPA.-ISB. March 25, 1983. Compliance Status of Facilities Subject
to Mercury National Emission Standard. (II-B-6).
29. Letter and attachments from Burkett, R., LCP Chemicals & Plastics,
Inc., to Farmer, J., EPArESED. March 10, 1983. Response to
' Section 114 information request. (II-D-35).
30. Letter and attachment from Heilala, J., Vulcan Chemicals, to
Farmer, J., EPArESED. February 22, 1983. Response to Section 114
information request. (II-D-27).
31. Reference 23, p. 6. (II-B-3).
32. Letter and attachments from Vaughn, D., Olin Chemicals Group, to
Georgieff, N., EPA:ISB. March 18, 1983. Transmittal of revised
trip report and comments on EPA housekeeping procedures. (II-D-38).
33. Telecon. Sauer, M., MRI, with McManus, P., EPA Region III.
January 20, 1983. Information on mercury NESHAP related to
chlor-alkali plants. (II-E-54).
34. Telecon. Atkinson, D., MRI, with Murphy S., Kentucky Division of
Air Pollution Control. January 3, 1983. Information on chlor-alkali
plants in Kentucky. (II-E-26).
35. Telecon. Atkinson, D. , MRI, with Hardy, G., Alabama Air Pollution
Control Commission. January 3, 1983. Information on Alabama
chlor-alkali plants. (II-E-25).
36. Telecon. Atkinson, D., MRI, with Palmer, T., Corpus Christi Region
of Texas Air Control Board. January 5, 1983. Information on
compliance with mercury NESHAP. (II-E-39).
3-16
-------
37. Telecon. Atkinson, D., MRI, with Varner, B., EPA Region V.
January 5, 1983. Information on compliance with mercury NESHAP.
(II-E-34).
38. Telecon. Atkinson, D., MRI, with Gaspercecz, G., Louisiana
Department of Natural Resources. January 6, 1983. Discussion of
mercury NESHAP. (II-E-44).
39. Telecon. Atkinson, D., MRI, with Styke, Q., and J. Haines,
Tennessee Division of Air Pollution Control. January 4, 1983.
Discussion of mercury NESHAP. (II-E-31).
40. Telecon. Atkinson, D., MRI, with Cook, North Carolina Division of
Environmental Management. January 4, 1983. Discussion of mercury
NESHAP. (II-E-29).
41. Telecon. Atkinson, D., MRI, with Fossa, A., New York Department of
Environmental Conservation. December 29, 1982. Discussion of
mercury NESHAP. (II-E-19).
3-17
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4. MERCURY ORE PROCESSING
4.1 INTRODUCTION
Currently only one mercury ore processing facility is in operation
in the U.S., the McDermitt Mine in McDermitt, Nevada, operated by Placer
Amex, Inc. Two gold mines producing mercury as a by-product also were
operating in Nevada in 1982.l,2 The State of Nevada considers these
by-product operations to be insignificant sources of mercury emissions.3
The national emission standard for mercury does not apply to by-product
mercury mines. In 1973, the year of promulgation of the national emission
standard, 24 mines produced mercury. Fourteen mines produced less than
10 flasks each in 1973 from mined ore dumps, cleanup operations, or as a
by-product. Only six mines were classified as consistent producers.4
Statistics for number of producing mines, mercury content of ore, mercury
production, and total mercury consumption are given in Table 4-1 for the
period 1970 to 1982. The large increase in mercury production from 1974
to 1976 was due to startup of the new McDermitt Mine capable of producing
20,000 flasks/yr (690 Mg/yr [750 tons/yr]) of mercury.5 The average
mercury content of ore also increased between 1974 and 1976 due to the
higher mercury content of the McDermitt Mine ore. Approximately one-half
of the total mercury consumed in the U.S. in 1982 was supplied by domestic
production. The remainder was supplied by imports, secondary mercury
production, and government sales of strategic materials.
The Bureau of Mines has estimated future probable production of
25,000 flasks of mercury per year based almost entirely on output from
the Nevada mine. This is expected to continue until the mine reserves
are exhausted, which is expected to occur about 1993. Zero production
is forecast for the year 2000.6 However, a representative of the McDermitt
4-1
-------
TABLE 4-1. MERCURY STATISTICS FOR UNITED STATES—1970 TO 19821,7-10
Year
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982C
No. of
producing
mines
79
56
37
24
12
13
7
5
2
3
4
3
3
Mercury
of
(kg/rag)
2.0
2.1
2.7
2.5
1.8
2.8
3.9
4.1
3.0
3.8
2.7
3.3
NAd
content
ore
(Ib/ton)
4.8
5.0
6.5
6.1
4.4
6.8
9.5
9.9
7.2
9.2
6.5
8.1
NA
Production
(No. of.
flasks)0
27,296
17,883
7,349
2,227
2,189
7,366
23,133
28,244
24,163
29,519
30,657
27,904
26,137
Total consumption
(No. of
flasks)
61,503
52,257
52,907
54,283
59,479
50,838
64,870
61,259
59,393
62,205
58,983
59,244
49,418
aT1,. ,. * • j
I *J
.operations, or as by-product.
DFlask = 34 kg (76 Ib) mercury.
.Preliminary.
QNA = Not available.
4-2
-------
Mine has stated that ore deposits at the mine have been found to be more
extensive than originally believed, thus extending considerably the
potential life of this facility.11 It is unlikely that other mines will
be opened or reopened. The McDermitt Mine has a competitive advantage
due to the rich ore deposit and efficient processing.11
4.2 PROCESS AND CONTROL TECHNOLOGY DESCRIPTIONS
4.2.1 Process and Control Technology12
A flow chart showing the processing of mercury ore is shown in
Figure 4-1. The ore is fed to a grinding mill where water is added to
produce a slurry. The mercury ore particles are separated as a concentrate
by flotation. The concentrate is then thickened, stored, and filtered
before being fed to a direct-fired multiple-hearth furnace. Temperatures
in the furnace vary between 650° and 870°C (1200° and 1600°F). The
calcined ore is discharged from the bottom of the furnace. The mercury
vapor-laden gas is discharged from the top of the furnace. The gas then
enters a dry cyclone where dust.is removed. Fans keep the entire furnace
system under a negative-pressure gradient to minimize fugitive emissions
of mercury vapor.
The direct-fired multiple-hearth furnace is a result of technological
developments occurring since the promulgation of the national emission
standard. The multiple-hearth furnace used at the McDermitt Mine replaced
the Gould rotary furnace that formerly was used in the industry.
After passage through the cyclone, the gas stream is introduced
into banks of vertical tube condensers in series. The mercury in the
gas stream is condensed and collected under water in containers called
launders. The mercury is then cleaned, stored in bulk, filtered, bottled,
and shipped.
The gas stream leaving the condenser is passed through a venturi
and impinger tower for particulate removal and through a sulfur dioxide
(S02) scrubber. The cleaned gas stream is then exhausted to the atmos-
phere at ambient temperature.
The systems described above have been designed to control S02 and
particulate emissions. They coincidentally control mercury to the level
of saturated vapor at ambient temperature, the approximate temperature
of the exhaust gas stream.
4-3
-------
FRESH WATER WELL
TAILINGS RECLAIM WATER
CYCtOME
CLASSIFIERS
CLEAMER
FLOTATION
ROUGHER
FLOTATIOM
50-TON ORE
HOPPER
FROMT—EMD
LOADER
RECLEANER
FLOTATIOM
SEMI
AUTOGEMOUS
MILL
CLEAN CAS TO
ATMOSPHERE
APROM ORE FEEDER
FLOTATIOM
COMCEMTRATE
THICKENER
DAMPER DUST
CYCLONE
CONDENSER
CONCENTRATE
STORAGE
6HEARTH
10' —DIAMETER
FURNACE
TAILINGS PONDS
MARKET
SCRUBBING WATCH
COOLING
STACK
FLASWNG6
WEIGHING
Figure 4-1. Flow chart showing processing of mercury ore.l2
-------
4.2.2 Emission Sources
The major emissions of mercury from a mercury ore processing operation
occur from the cooling stack.
4.2.3 Wastes12
Tails from the flotation operations, calcines from the furnace,
dust captured by the cyclone, and scrubbing water are sent to a series
of large, shallow ponds. Treatment consists of natural evaporation over
a period of about 9 months.
4.3 COMPLIANCE TEST RESULTS
Mercury emission tests were conducted on the condenser stack of the
McDermitt Mine processing facility in 1981. Tests were run in accordance
with EPA Method 101. The average emission rate determined in two 2-hour
tests was 816 g/d (1.8 Ib/d) of mercury.12 The maximum daily emission
rate from this source was calculated to be approximately 1,360 g/d
(3.0 Ib/d) of mercury assuming stream saturation.13 Thus, this facility
is in compliance with the national emission standard.
The McDermitt Mine has had no problems in complying with the standard.
The control technology for S02 and particulate emissions has been reliable.1
4.4 ENFORCEMENT ASPECTS
No problems with enforcement of the standard for mercury ore processing
were noted either by EPA regional or State personnel contacted during this
study.3,14
4.5 SUMMARY AND CONCLUSIONS
Currently there is only one mercury ore processing facility in the
U.S. This facility is in compliance with the national emission standard
for mercury. No enforcement problems with the standard have been
encountered by EPA regional or State personnel.
4.6 REFERENCES FOR CHAPTER 4
1. Telecon. Sauer, M., MRI, with Carrico, L., Bureau of Mines. March 24,
1983. Information on mercury mining. Docket No. A-82-41, Document
No. (II-E-111).
2. Telecon. Keller, P., MRI, with Carrico, L. , Bureau of Mines.
July 11, 1983. Information on mercury mining. (II-E-128).
4-5
-------
3. Telecon. Newton, D., MRI, with Livak, J., Nevada Department of
Environmental Protection. January 14, 1983. Discussion of mercury
emission sources. (II-E-51).
4. U.S. Department of the Interior, Bureau of Mines. Minerals Yearbook,
1973, Volume I, Metals and Minerals, Mercury. Washington, D.C.
1974. p. 757. (II-I-3).
5. U.S. Department of the Interior, Bureau of Mines. Minerals Yearbook,
1975, Volume I, Metals and Minerals, Mercury. Washington, D.C.
1976. p. 894. (II-I-9).
6. U.S. Department of the Interior, Bureau of Mines. Mercury, A
Chapter from Mineral Facts and Problems, 1980 Edition. Preprint
from Bulletin 671. p. 11. (II-I-17).
7. U.S. Department of the Interior, Bureau of Mines. Mineral Industry
Surveys—Mercury in the Fourth Quarter 1982. Washington, D.C.
March 11, 1983. p. 2. (II-I-29).
8. U.S. Department of the Interior, Bureau of Mines. Preprint from
the 1981 Bureau of Mines Minerals Yearbook-Mercury, pp. 1, 2.
(II-I-21).
9. U.S. Department of the Interior, Bureau of Mines. Minerals Yearbook,
1978-79, Volume I, Metals and Minerals, Mercury. Washington, D.C.
1980. p. 594. (II-I-16).
10. U.S. Department of the Interior, Bureau of Mines. Minerals Yearbook,
1974, Volume I, Metals and Minerals, Mercury. Washington, D.C.
1975. pp. 800, 801. (II-I-6).
11. Telecon. Peckworth, D., MRI, with Botts, V., Placer Amex, Inc.
April 18, 1983. Discussion of the Mercury NESHAP as applied to the
McDermitt Mine. (II-E-114).
12. Letter and attachments from Botts, V., Placer Amex Inc. , to
Georgieff, N. , EPA:ISB. August 5, 1982. Information on mercury
ore processing. (II-D-9).
13. Memorandum from Atkinson, D., MRI, to Project File 7703-L. August 8,
1983. Calculation of maximum mercury emission rate from the McDermitt
Mine. (II-B-15).
14. Telecon. Newton D., MRI, with Okamoto, M., EPA Region IX. January 11,
1983. Discussion of mercury emission sources. (II-E-50).
4-6
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5. SLUDGE INCINERATION AND DRYING
5.1 INTRODUCTION
Information on sludge incineration and drying was obtained primarily
from the EPA Stationary Source Compliance Division and from telephone
contacts with EPA regional personnel and State personnel. According to
the EPA Compliance Data System report for the mercury national emission
standard, there were 172 incineration sites subject to the national
emission standard at the end of 1982.1 The total number of municipal
and industrial wastewater sludge incinerators at these sites is estimated
to be in the range of 258 to 280.1 Five sludge drying plants with at
least 9 dryers were also listed as subject to the standard.1
In 1973 there were an estimated 280 municipal sludge incinerators,
17 sludge dryers, and an undetermined number of industrial sludge incin-
erators.2 A 1975 EPA estimate of growth through 1980 placed the number
of sewage sludge incinerators in 1980 at 725.3 The anticipated growth
in sludge incineration as a sludge disposal technique did not materialize;
the number of sludge incinerators today is essentially the same as in
1973. Future growth potential of sludge incineration was not examined.
Vendor sales information indicates that the typical size of new
sludge incineration plants increased during the period from 1973 to
1981. In 1973, EPA estimated the size distribution of sludge burning
plants in terms of dry solids burning capacity. A size distribution of
new plants constructed between 1974 and 1981 was developed from installatior
lists obtained from the two major vendors of multiple-hearth and fluidized-
bed incinerators.4,5 The size distributions are compared in Table 5-1.
As shown in this table, the majority of new sludge incineration plants
are of greater than 45-Mg/d (50-ton/d) capacity.
5-1
-------
TABLE 5-1. SIZE DISTRIBUTION OF SLUDGE INCINERATION PLANTS
EXISTING IN 1973 AND CONSTRUCTED BETWEEN 1974 AND 19816,7
Plant size (dry solids
burning capacity)
Mg/d
tons/d
Plants
existing in 1973
No. of JTof
plants total
Plants
constructed between
1974 and 1981
No. of
plants
% of
total
<4.5
4.5-45
45-227
>227
<5
5-50
50-250
>250
17
173
37
6
7
73
16
3
2
10
19
7
5
26
50
19
TOTAL
233
100
38
100
5-2
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5.2 PROCESS AND CONTROL TECHNOLOGY DESCRIPTIONS
5.2.1 Sludge Incineration
Incinerators are used for treatment of sludge produced by municipal
or industrial wastewater treatment plants. Incineration is a two-step
process that involves first drying and then combustion. In all furnaces,
the temperature of the dewatered feed sludge is raised to 100°C (212°F)
to evaporate water from the sludge; then, the temperature of the water
vapor, air, and sludge is increased to the ignition point of the sludge
volatiles. Two major types of sludge incinerators are used in the U.S.:
the multiple-hearth and the fluidized-bed. These are described in the
following sections. Other incineration processes in limited use are the
electric furnace, single hearth cyclonic furnace, and high-pressure/high-
temperature wet air oxidation. Detailed descriptions can be found in
the EPA Process Design Manual for Sludge Treatment and Disposal.8
5.2.1.1 Multiple-Hearth Incineration.8 The multiple-hearth furnace
is the most widely used sludge incinerator in the U.S. A process flow
diagram for sludge incineration in a multiple-hearth furnace is shown in
Figure 5-1. The multiple-hearth furnace consists of a cylindrically
shaped steel shell containing a series of refractory hearths, one above
the other. The multiple-hearth furnace can have from 4 to 14 hearths.
A central shaft supports rabble arms above each hearth, which rake the
sludge across the hearth in a spiral pattern. The sludge is fed in at
the top hearth and successively drops down to the next hearth. Combustion
air is supplied at the bottom of the furnace. The countercurrent flow
of rising hot combustion gases and descending sludge provides contact,
which ensures combustion of the sludge. Supplemental fuel may be supplied.
Cooling air for the central shaft and rabble arms is supplied at the
bottom of the furnace. After cooling the shaft, the air is either
discharged to the atmosphere or returned to the bottom hearth as preheated
air for combustion. Incineration temperatures range from 760° to 927°C
(1400° to 1700°F).
5.2.1.2 Fluidized-Bed Incineration.8 Fluidized-bed furnaces are
also used to incinerate wastewater treatment plant sludges. A process
flow diagram for sludge incineration in a fluidized-bed furnace is shown
in Figure 5-2. The fluidized-bed furnace is a cylindrically shaped
5-3
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GAS EXHAUST
SHAFT COOLING AIR NOT RETURNED
C7-
SHAFT
VENTURI WATER
CONNECTED TOWER
ASH
COOLING AIR
Figure 5-1. Process flow diagram for sludge
incineration in a multiple-hearth furnace.^
5-4
-------
FURNACE EXHAUST
GAS EXHAUST
BED COILS FOR
HEAT RECOVERY
Figure 5-2. Process flow diagram for sludge
incineration in a fluidized-bed furnace.10
5-5
-------
steel shell that contains a sand bed and fluidizing air diffusers.
Sludge is injected either above or directly into the bed, and air is
introduced at the bottom of the bed to fluidize the mixture of sand and
sludge. Combustion occurs in the bed at 760° to 816°C (1400° to 1500°F).
Supplemental fuel may be supplied. Ash is carried out the top of the
furnace with the combustion exhaust.
5.2.1.3 Control Technology for Sludge Incineration. Wet scrubbers
are typically used to control particulate emissions to meet the new
source performance standard for incinerators that burn municipal wastewater
sludge. Some mercury may be incidentally removed by the wet scrubbers.
Common scrubber configurations include variable throat venturi scrubbers
in series with cyclonic mist eliminators, venturi scrubbers in series
with perforated-plate impingement scrubbers, or multiple series of
perforated-plate impingement scrubbers. Pressure drops may range from
1,493 to 8,709 Pa (6 to 35 in. WG).11
5.2.2 Sludge Drying12
Heat drying is used to evaporate water in the sludge. Conventional
heat-drying systems include rotary kiln drying, flash drying, drying in
incinerators, and spray drying. Before heat drying, the sludge is
usually mechanically dewatered. In the dryer, water that was not mechanica
separated is evaporated without decomposing the organic matter in the
sludge solids. The solids temperature in the dryer must be kept between
60° and 93°C (140° and 200°F). The dried sludge is either stored in
bulk for disposal or sent to a furnace for incineration. The exhaust
gas stream may go to a treatment system for removal of particulate
matter and odors. Control techniques that can be used to treat emissions
from sludge drying include afterburners, cyclones, wet scrubbers, electro-
static precipitators, and baghouses.
5.3 COMPLIANCE TEST RESULTS
The compliance status for sludge incineration and sludge drying
plants is listed by the EPA's Compliance Data System (CDS). The CDS
indicates that all facilities presently comply with the national emission
standard for mercury.1 Test results for a number of sludge incinerators
were obtained from EPA and State personnel from regions containing
significant sludge incineration operations. The mercury content of
5-6
-------
muncipal sewage sludge has been reported to range from 0.1 to 89 ppm,
have a mean of 7 ppm, and have a median of 4 ppm.13 Due to its volatility,
most of the mercury contained in the sludge feed is vaporized during
incineration and is emitted as mercury vapor.
The mercury emission data obtained in this study for sludge incinerate
are given in Table 5-2. Mercury emissions were measured either by stack
tests using EPA Method 101A or by sludge analysis using Method 105 and
calculation of maximum emissions. All test data are less than 3,200 g/d
(7 Ib/d). Emissions ranged from 0 to 1,234 g/d total mercury (0 to
2.7 Ib/d). The highest emissions were associated with the Cleveland,
Ohio, and Detroit, Michigan, treatment plants. These were the only
plants for which test data were obtained with sludge charging rates of
greater than 227 Mg/d (250 ton/d) of dry solids.
5.4 ENFORCEMENT ASPECTS
No problems with enforcement of the standard for sludge incineration
and drying were noted during this study. None of the persons contacted
was aware of any source that was out of compliance with the standard.
5.5 SUMMARY AND CONCLUSIONS
All sludge incinerators and dryers are in compliance with the
national emission standard for mercury. No problems with enforcement of
the standard have been noted.
5-7
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TABLE 5-2. MERCURY EMISSION DATA FOR SLUDGE INCINERATORS
Plant/location
EPA Reqion I
Norwalk Sewage Treatment
Norwalk, Conn.
Metropolitan District
Hartford, Conn.
New Haven Sewage Treatment
Plant, New Haven, Conn.
EPA Region II
Jersey City Sewerage
Jersey City, N.J.
Northwest Bergen Co. Sewage
Authority, Waldwick, N.J.
Parsippany-Troy Hills
Parsippany-Troy Hills, N.J.
Stony Brook Sewage Treatment
Plant, Princeton, N.J.
ACSD-N. Plant, Menands, N.Y.
ACSO-S. Plant, Albany, N.Y.
Amherst STP, Amherst, N.Y.
Bath WTP, Bath, N.Y.
Beacon Sewage Sludge In.
Beacon, N.Y.
Buffalo Sewer Auth.
Buffalo, N.Y.
Liberty STP
Little Falls Plant
Little Falls, N.Y.
Monroe Co. -STP, N.Y.
Monti cello STP,
Monticello, N.Y.
New Roche lie STP
New Rochelle, N.Y.
Oneida STP, Utica, N.Y.
Oswego E.S., Oswego, N.Y.
Port Washington WPCD
Port Washington, N.Y.
Saratoga Co., Halfmoon, N.Y.
Schenectady STP
Schenectady, N.Y.
Tonawanda STP, Tonawanda, N.Y.
Watertown STP, Watertown, N.Y.
Atlantic Co. Sewerage
Authority-Coastal Region
Atlantic City, N.J.
Bayshore Regional Sewage
Authority, Union Beach, N.J.
Prasa, Puerto Nuevo, P.R.
EPA Region III
Allegheny Co. Sanitation
Authority, Pittsburgh, Pa.
Erie STP, Erie, Pa.
Hazel ton STP, West
Hazelton, Pa.
City of McKeesport
McKeesport, Pa.
No. of
incin-
erators
tested
1
1
1
1
1
1
1
1
1
1
1
1
NA
NA
NA
NA
1
1
1
NA
NA
1
1
1
1
1
1
1
NA
NA
1
1
1
1
1
Sludge
rate,
Mg/day
NAb
NA
NA
NA
3.9
25-°c
21. 8C
1.0
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
57C
/*
33C
NA
34
NA
NA
NA
NA
charging
dry solids
(tons/day)
(NA)
(NA)
(NA)
(NA)
(4.4)
(27.6)
(24.0)
(1.1)
(NA)
(NA)
(NA)
(NA)
(NA)
(NA)
(NA)
(NA)
(NA)
(NA)
(NA)
(NA)
(NA)
(NA)
(NA)
(NA)
(NA)
(NA)
(NA)
(63)
(36)
(NA)
(93)
(NA)
(NA)
(NA)
(NA)
Total
Hg emissions
g/day
217
129
423
•32
0.1
343<;
18C
37
51
147
33
175
72d
64
539
6d
3
32-64
0
A
476d
16d
443
29
177
4
400
05
61C
0
3
253
a
500*
450e
4
25
(Ib/day)
(0.48)
(0.28)
(0.93)
(0.07)
(0)
(0.76)
(0.04)
(0.08)
(0.11)
(0.32)
(0.07)
(0.39)
(0.16)
(0.14)
(1.19)
(0.01)
(0.02)
(0.07-
0.14)
(0)
(1.05)
(0.04)
(0.98)
(0.06)
(0.39)
(0.01)
(0.88)
(0)
(0.13)
(0)
(0.01)
(0.56)
(1.32)
(0.99)
(0.01)
(0.06)
Date
of
test
1977
1979
1981
NA
1981
1978
1978
NA
NA
NA
NA
NA
NA
1976
1977
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
1980
1981
NA
1976
1975
1975
1978
Ref.
No.
14
14
14
15
15
15
15
15
15
15
15
15
15
15
15
15
15
15
15
15
15
15
15
15
15
15
15
15
15
16
17
17, 18
17
17
(continued)
5-8
-------
TABLE 5-2. (continued)
Plant/location
Morrisville Municipal STP
Morrisville, Pa.
Scranton Sewer Authority
Scranton, Pa.
Swatara Township,
Hummel ston, Pa.
Huntington Treatment Plant
Huntington, Pa.
Appolo Treatment Plant
Appolo, Pa.
Tyrone Borough Municipal
Authority, Tyrone, Pa.
York City Sewer
Authority, York, Pa.
EPA Re_ai on V
Metropolitan Wastewater
Treatment Plant
St. Paul , Minn.
Seneca Wastewater Treatment
Plant, Minneapolis/
St. Paul , Minn.
Mill Creek Treatment Works
Cincinnati, Ohio
Muddy Creek Treatment Works
Cincinnati, Ohio
Southerly Wastewater Treatment
Center, Cleveland, Ohio
Detroit Wastewater Treatment
Plant, Detroit, Mich.
EPA Region VI
North Texas Municipal Water
District Wylie, Tex.
Olin Corp., Lake Charles, La.
No. of
incin-
erators
tested
1
1
1
1
1
1
1
1
1
1
NA
NA
4
NA
NA
NA
NA
NA
NA
NA
NA
NA
1
Sludge
rate,
Mg/day
0.1
30
NA
NA
NA
NA
NA
56
163
32
16.7
2.7
305
306
293
174
602
540
430
406
256
12.5
2.6
charging
dry solids
(tons/day)
(0.13)
(33)
(NA)
(NA)
(NA)
(NA)
(NA)
(73)
(180)
(35)
(18.4)
(3.0)
(336)
(337)
(323)
(192)
(664)
(595)
(474)
(447)
(282)
(13.8)
(2-9)
Total
Hg emissions
g/day
20
84
10
9
17e
17e
20d
36S
137d
21d
77d
14d
l,037g
1,220°
(at
capacity)
516d
493d,
366d
l,234d
l,107d
600d
752d
312d
4d
1.5d
(Ib/day)
(0.04)
(0.19)
(0.02)
(0.02)
(0.04)
(0.04)
(0.04)
(0.08)
(0.30)
(0.05)
(0.17)
(0.03)
(2.29-
2.69)
(1.14)
(1-09)
(0.81)
(2.72)
(2.44)
(1.32)
(1.66)
(0-69)
(0.01)
(0)
Date
of
test
1978
1977
1975
1975
NA
1977
1981
1976
1976
1976
1976
1976
1976
1977
1977
1978
1979
1979
1980
1981
1982
1977-78
NA
Ref.
No.
17
17
17
17
18
19
19
20
20
20
20
20
20
20
20
20
20
20
20
20
20, 21
22
22
Except where indicated, it is not known whether emissions were measured in stack test or by sludge
analysis. Where measured by sludge analysis, results are maximum emissions, assuming zero percent
Deduction of mercury by control equipment.
NA = not available.
.Average of several runs was computed and is reported here.
Based on sludge test.
Based on stack test.
5-9
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5.6 REFERENCES FOR CHAPTER 5
1. Memorandum from Newton, D. , and Sauer, M., MRI, to Georgieff, N.,
EPArlSB. March 25, 1983. Compliance Status of Facilities Subject
to Mercury National Emission Standard. Docket No. A-82-41,
Document No. (II-B-6).
2. U.S. Environmental Protection Agency. Background Information on
National Emission Standards for Hazardous Air Pollutants—Proposed
Amendments to Standards for Asbestos and Mercury. EPA-450/2-74-009a.
Research Triangle Park, North Carolina. October 1974. p. 75.
(II-A-5).
3. Reference 2, p. 89. (II-A-5).
4. Letter and attachments from Shedlow, R., Nichols Engineering &
Research Corporation, to Sauer, M., MRI. February 14, 1983. List
of multiple-hearth sludge furnace installations. (II-D-25).
5. Letter and attachments from Conradsen, J., Dorr-Oliver Incorporated,
to Newton, D., MRI. February 9, 1983. List of fluidized bed
incinerator installations. (II-D-23).
6. Reference 2, p. 86. (II-A-5).
7. Memorandum from Sauer, M., MRI, to Project File 7703-L.. May 4,
1983. Sludge Incineration Plants. (II-B-8).
8. U.S. Environmental Protection Agency. Process Design Manual for
Sludge Treatment and Disposal. EPA 625/1-79-011. Cincinatti, Ohio.
September 1979. pp. 11-1 to 11-149. (II-A-9).
9. Reference 8, p. 11-37. (II-A-9).
10. Reference 8, p. 11-52. (II-A-9).
11. U.S. Environmental Protection Agency. A Review of Standards of
Performance for New Stationary Sources--Sewage Sludge Incinerators.
EPA-450/2-79-010. Research Triangle Park, North Carolina.
March 1979. p. 4-19. (II-A-8).
12. Reference 8, pp. 10-1 to 10-33. (II-A-9).
13. Gerstle, R., and Albrinck, D. Atmospheric Emissions of Metals from
Sewage Sludge Incineration. Journal of the Air Pollution Control
Association. 32:1119-1123. November 1982. (II-I-25).
14. Telecon. Newton, D., MRI, with Michel, T., EPA Region I. February 2,
1983. Information on mercury emissions from sludge incineration.
(II-E-71).
5-10
-------
15. Letter and attachments from Jung, T., EPA Region II, to Georgieff, N.,
EPA:ISB. August 3, 1982. Information on mercury emissions.
(II-D-8).
16. Telecon. Newton, D., MRI, with Rieva, S. , EPA Region II.
February 1, 1983. Information on mercury emissions. (II-E-67).
17. Telecon. Newton, D., MRI, with Mykijewycz, B., EPA Region III.
January 28, 1983. Information on mercury emissions. (II-E-61).
18. Reference 12, p. 5-15. (II-A-9).
19. Letter and attachments from Johnson, R., Pennsylvania Department of
Environmental Resources, to Newton, D., MRI. February 4, 1983.
Information on mercury emissions. (II-D-21).
20. Letter and attachments from Varner, B., EPA Region V, to Newton, D.,
MRI. February 7, 1983. Information on mercury emissions.
(II-D-22).
21. Letter and attachments from Varner, B., EPA Region V, to Newton, D.,
MRI. March 7, 1983. Information on mercury emissions. (II-D-32).
22. Letter and attachments from Taylor, W., EPA Region VI, to
Georgieff, N., EPA:ISB. August 24, 1982. Information on mercury
emissions. (II-D-11).
5-11
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-------
6. SOURCES NOT REGULATED BY THE STANDARD
6.1 INTRODUCTION
Mercury is emitted to the atmosphere from a number of sources in
addition to those regulated by the national emission standard. Sources
were investigated as potential candidates for regulation based on whether
the source has the potential to emit mercury in a manner that could
cause the inhalation health effects limit of 1.0 ug/m3 (4.37xlO-7 gr/ft3)
(daily concentration averaged over 30 days) to be exceeded. For the
purpose of the following discussion, sources of mercury air emissions
are divided into three general categories: (1) sources that process
materials containing mercury, (2) sources that use mercury in the process,
and (3) sources that recover mercury.
6.2 GENERAL
Sources that process material containing mercury include fossil
power plants, nonferrous smelters, municipal solid waste incinerators,
peat to methanol conversion plants, and geothermal power plants. Power
plants emit mercury to the air because of the mercury content of the
fossil fuel. Mercury contained in sulfide concentrates may be emitted
to the atmosphere during zinc, copper, and lead smelting operations.
The EPA did not regulate power plants and smelters under the original
standard because it was found that mercury emissions, even assuming
restrictive dispersion conditions and uncontrolled emissions, would not
cause the ambient concentration guideline to be exceeded.1,2 A recent
study of mercury emissions from power plants supports this conclusion.3
Solid waste incinerators emit mercury to the air when batteries,
control instruments, mercury-containing lamps, and other mercury-containing
scrap are incinerated. Mercury air emissions from a solid waste incinerate-
6-1
-------
(average load of 9 Mg/h [10 tons/h]) were estimated in 1974 to be about
30 g/h (0.07 Ib/h) based on the national average for the mercury content
of solid waste.4 Plants currently in operation average approximately
the same load capacity as 1974 plants, with the largest plant operating
with a load capacity of approximately 36 Mg/h (40 tons/h).5 Emission
levels from these plants would not cause the ambient concentration
guideline to be exceeded; therefore, waste incineration was not investigate
further in this study.
No peat-to-methanol conversion plants have been constructed in the
United States; however, one is under construction in Creswell, North
Carolina. It will have the potential for mercury emissions due to the
mercury content of peat. The facility has been granted its air permit.
Estimates of its yearly mercury emissions are 0.059 Mg (0.065 tons), or
0.0068 kg/h (0.015 Ib/h). Because this emission level is below the
0.09-Mg/yr (0.1-ton/yr) guideline for mercury, which would require that
the source be permitted specifically for mercury, ambient mercury concen-
trations are not expected to endanger public health.6
Geothermal power plants have the potential for mercury emissions
because the hot water and steam can dislodge mercury deposits from
within the earth. At present, however, there is no indication that
uncontrolled mercury emissions from these facilities could approach a
level that would cause the health effects guideline to be exceeded.7,8
One study indicates that daily mercury emissions from geothermal power
plants, 25 to 75 megawatts, would be approximately 36 to 144 g, far
below the current standards for the regulated source categories.7
Sources that use mercury and that may emit mercury to the air
include: battery manufacturing, mercury vapor lamp manufacturing,
by-product mercury from gold mining, instrument manufacturing, paint
manufacturing, manufacture of mercury compounds, laboratory use of
mercury, and use of dental amalgams. The amount of mercury used in the
U.S. in 1982 by each of these as well as other source categories is
listed in Table 6-1.9 Because of the large amount of mercury used in
battery manufacturing (about one-half of all mercury consumed in U.S.)
and concern expressed by one State over mercury emissions at one facility,
it was decided to investigate this source further as a candidate for
6-2
-------
TABLE 6-1. UNITED STATES MERCURY CONSUMPTION IN 19823'9
Flasks5
Chemicals and allied products:
Chlorine and caustic soda preparation 6,516
Pigments W
Catalysts W
Laboratory uses 160
Plastic materials and synthetic (processing resins) W
Paints 6,794
Agricultural chemicals 36
Installation and expansion of chlorine and caustic
soda plants W
Chemicals and allied products, n.e.c. W
Electrical and electronic instruments:
Electrical lighting W
Wiring devices and switches 1,747
Batteries 24,066
Other electrical and electronic equipment 6
Instruments and related products:
Measuring and control devices 2,916
Dental equipment and supplies 1,027
Other instruments and related products W
Other identified end uses:
Refining lubricating oils W
Other . 3,147
TOTAL0 49,418
^Preliminary data for 1982.
°0ne flask = 34 Mg (76 Ib).
W = Withheld to avoid disclosing company proprietary data; included in
."Other."
Data do not add to totals shown; totals include estimates for companies
reporting annually.
6-3
-------
regulation. Findings are presented in Section 6.3. The other sources
listed above are not likely to cause the ambient concentration guideline
to be exceeded. This determination was made on information on the
amounts of mercury consumed and the types of processes involved.9,10
Sources that recover mercury from scrap include retorting and
distillation operations. Production of secondary mercury totaled
4,244 flasks in 1981 compared to 27,888 flasks produced in 1981 from
mining.11 It was decided to investigate secondary recovery by retorting
as a candidate for regulation because of the quantity of mercury handled
and the potential for emissions to the air. Findings of this investigatior
are presented in Section 6.4. Cleaning of mercury by vacuum distillation
is done in some facilties where the purity of mercury is important.
Maximum mercury emissions from vacuum distillation have been estimated
to be 9 g per 345 kg (0.02 Ib per 760 Ib) of mercury produced.12 Because
of the small amount of mercury emissions, it is unlikely that this
source could cause the ambient concentration guideline to be exceeded.
6.3 BATTERY MANUFACTURING
Mercury in the form of zinc amalgam, mercuric oxide (HgO), mercuric
chloride (HgCl2), or mercurous chloride (Hg2Cl2) is a component of most
primary batteries and some storage batteries. Information on battery
manufacturing plants operated by three companies—Union Carbide Corporatior
Duracell Inc., and Ray-0-Vac Corporation—was obtained through contacts
with State agencies and the industry. These companies were selected
because they are believed to represent almost all mercury battery manu-
facturing in the U.S. Information was obtained for five plants
manufacturing mercuric oxide-zinc or mercuric oxide-cadmium batteries,
seven plants manufacturing alkaline-manganese batteries, and seven plants
manufacturing Leclanche carbon-zinc batteries. One mercuric oxide-zinc
and two alkaline-manganese manufacturing facilities were visited. The
mercury emission potential of battery manufacturing facilities is discussec
below.
6.3.1 Mercuric Oxide Battery Manufacturing
6.3.1.1 Process. Mercuric oxide is used in the cathodes of mercuric
oxide-zinc and mercuric oxide-cadmium cells, and zinc amalgam is used in
6-4
-------
the anodes of mercuric oxide-zinc cells. A general flow diagram for
these processes is given in Figure 6-1. The cathode is a mixture of
mercuric oxide, graphite, and manganese dioxide. In mercury button
cells, this mixture is pre-formed into pellets. The anode is a zinc
amalgam. The dried amalgam is pre-formed into pellets for mercury
button cells. The anode and cathode are enclosed in a can with appropriate
separators, electrolyte, and other components to form a cell. Mercury
consumption in each of the five plants manufacturing mercuric oxide
batteries ranges from <4.5 to >1,100 kg/d (<10 to >2,500 Ib/d) of mercury.;
One facility investigated in this study also manufactures mercuric
oxide and operates a secondary mercury recovery plant on-site.14 Mercuric
oxide is manufactured in a two-step process at this facility. Figures 6-2
through 6-4 are flow diagrams for this plant. In the first step, mercury
and chlorine are combined in a reactor containing a brine solution to
form mercuric chloride. Sodium hydroxide is then combined with this
product in a second reactor to produce mercuric oxide. The mercuric
oxide precipitate is processed and transported to the main plant for
cathode manufacture.
The main plant of the integrated battery manufacturing facility
(battery manufacture, mercuric oxide manufacture, and secondary recovery
at one site) consists of a cathode area, anode room, and cell assembly
room. In the cathode area, graphite, manganese dioxide, and mercuric
oxide are blended, pelleted, granulated, and consolidated to form the
cathode material. In the anode room, anode material is formed by amal-
gamating zinc and mercury followed by dewatering, traying, drying,
sieving, blending, and pelleting steps. Cathode and anode material are
combined in the cell assembly area.
Secondary recovery operations at this facility consist of recovery
of mercury from batteries and manufacturing scrap in retorts. This
process is discussed further in Section 6.4--Secondary Recovery of
Mercury in Retorts.
6.3.1.2 Mercury Emissions Potential. This discussion is separated
into two sections: the emission potential for an integrated battery
manufacturing facility and the emissions potential for other mercuric
oxide battery manufacturing facilities.
6-5
-------
cr»
en
ANODE
(MERCURIC OXIDE—ZINC CELLS)
EMISSIONS
Hg
Zn
HgO
AMALGAMATING
EMISSIONS
EMISSIONS
PROCESSING
EMISSIONS
PROCESSING
EMISSIONS
CELL ASSEMBLY
-^BATTERIES
GRAPHITE—4 MIXING AND
Hn02 ] BLENBiNG
CATHODE
(MERCURIC OXIDE—ZINC AND MERCURIC OXIDE—CADMIUM CELLS)
Figure 6-1. General flow diagram for mercuric oxide battery manufacture,
-------
TO ATMOSPHERE
en
i
TO ATMOSPHERE
C12
SCRUBBER
TO ATMOSPHERE
NaOH
DISCHARGE
UNDER WATER
INSIDE PLANT
C)2
PRIMARY
REACTOR
HflCl2
P
4
INTER-
MEDIATE
STORAGE
u
to
"* RECYCLED BRINE
SECONDARY
REACTOR
Hgo
P*
WASHING
fe.
P"
DEWATERING
k.
r
*
1
VACUUM
DRYER
— ^
4
1
PACKAGING
HgO TO
• MAIN
PLANT
Figure 6-2. Process flow diagram for oxide plant.
-------
Ol
00
Zn-fc
CATHODE
(D
i
AMALGAMATING
ARE)
\
(A)
if
^
DEUATERING
(A)
jf
i
TRAY ING
(A)
BAG-
iOUSE
1
1
1
^_
(£\
V^jX
1
DRYING
fc~
w
bltVlnu
-
®
7f
1
DLtNUlNu
^
PELLETING
(ANODE)
i
.^
CELL >
ASSEMBLY 1 .
ROOM , '
1
4 1
, *•
1
I
I
1 V
1
HEATING/AC
AIR
PREFILTERS
CHARCOAL
FILTERS
ANODE ROOM
TO ATMOSPHERE
-------
en
I
UD
r
i
u -r
RETORT
CHAMBER
CONDENSER
r
i
H20
> -*i
AIR
GAP
H20
Hg COLLECTOR
I
I
JL
SCRUBBER
Figure 6-4. Process flow diagram for mercury recovery plant,
-------
6.3.1.2.1 Integrated mercuric oxide battery manufacturing facility.
Sources of mercury emissions to the air at the integrated battery facility
include sources at the main plant, oxide plant, and recovery plant.
Emission sources are listed in Table 6-2 along with control devices and
mercury emission estimates and test data if available.
Total mercury emissions from the main plant are estimated to be
97.9 g/d (0.216 Ib/d). In the cathode production area of the main
plant, particulate mercury emissions originate during the blending,
pelleting, handling, compacting, transfer, and consolidating operations.
Process and machine enclosure exhaust systems are ducted to baghouses
for particulate control. A vacuum system is used for cleanup of spills.
In the anode production area of the main plant, mercury vapor and
particulate may be emitted during the multiple-step amalgamation process
from the blending of mercury and zinc oxide, and the dewatering, drying,
and reblending of the amalgam. These processes are all exhausted uncon-
trolled to the atmosphere. A vacuum is also used to collect scrap in
the anode production area.
In the cell assembly area of the main plant, mercury particulate
and vapor emissions can originate from assembly operations because both
cathode and anode materials are involved. A baghouse controls particulate
emissions from the assembly lines. Ventilation air in the cell assembly
area is recirculated through prefilters and charcoal filters.
At the oxide plant, mercury emission sources include: mercury
transferring operations open to the atmosphere, reactors, vacuum dryers,
packaging, mercury distillation, and roof vents. Emissions from packaging
are controlled by a baghouse and particulate filters. Chlorine recovery
emissions are controlled by a scrubber, and rear reactor emissions are
limited by a condensing duct. Mercury emissions from two sources at the
oxide plant—the secondary (rear) reactor and the baghouse on packaging—
measured a combined 118 g/d (0.26 Ib/d) in a 1981 test.15,16 The company
estimated mercury emissions from the room ventilation systems at about
50 to 100 g/d (0.11 to 0.22 Ib/d).17
At the recovery plant, mercury vapor emission sources include the
silver furnace and two mercury retort furnaces. A wet scrubber controls
mercury vapor emissions from the mercury retorts.15 A baghouse controls
6-10
-------
TABLE 6-2. EMISSION SOURCE PARAMETERS FOR THE INTEGRATED MERCURY BATTERY MANUFACTURING FACILITY15-17
Building/source No. description3
Emission rate
g/d
Ib/d
Exit
temp.
Control device
Main plant
Control room
1. Blending/slugging/compacting/granulating 6.12
2. Slugging/granulating 1.22
3. Pelleting/consolidating 1.63
4. Pelleting/consolidating 0.91C
4a. Pelleting/consolidating 0.91°
5. Pelleting/consolidating 42.46
5a. Pelleting/consolidating 6.53
6. Blending/compacting/granulating/pelleting/ 1.36C
consolidating
Anode room
7.
7a.
7b.
7c.
11.
Cell
Amalgam/pelleting
Amal gam/dewateri ng
Vacuum dryer
Blending
Pelleting/zinc amalgam
assembly area
0.91C
1.82C
0.46C
0.91C
4.08C
0.0135
0.0027
0.0036
0.002C
0.002
0.0936
0.0144
0.003a
0.002C
0.004C
0.001C
0.002C
0.009C
297
297
295
295
295
297
297
297
297
297
297
297
295
Baghouse
Baghouse
Baghouse
House vacuum
House vacuum
Baghouse
Baghouse
Baghouse
House vacuum
Uncontrolled
Uncontrolled
Uncontrolled
Baghouse
8. Assembling cells
28.58
0.0630
295
Baghouse
(continued)
-------
TABLE 6-2. (continued)
Emission rate
Building/source No. description'
g/d
Ib/d
Exit
temp.
~*
Control device
en
i
Oxide plant
9. HgO transfer/packing
9a. C12 recovery reactor
9b. Rear reactors
Room vents
Recovery plant
35.92 0.0792
- Not tested or -
estimated
84.10.
0.1854
49.90-99.80" 0.11-0.221
299 Baghouse/HEPA filter
299 Scrubber
325 Condensing duct
Uncontrolled
10. Silver furnace 13.61
lOa Recovery furnaces 122.46
& lOb.
TOTAL 453.79
^Source numbers are the same code used by Duracell.
Emission rates were measured by Duracell except where noted.
^Estimated emission rate by Duracell.
Estimated emission rate by Duracell in Reference 17.
0.031- 422
0.270 294
1.0
See Reference 15.
Baghouse
Scrubber
-------
silver furnace emissions. Total mercury emission from the recovery
plant are estimated by company personnel to be 136 g/d (0.30 lb/d).15
Total mercury emissions from all sources at this facility are
estimated by company personnel to be a maximum of 454 g/d (1.0 Ib/d).
The primary emphasis at the plant has been to reduce operator exposure
to mercury and to control particulate mercury emissions from the plant.
Mercury vapor emissions from the main plant and oxide plant are generally
uncontrolled.
In addition to stack testing conducted in 1981 at this facility,
ambient monitoring of both mercury particulate and vapor was performed.
Particulate mercury measured at three off-site locations ranged from
below the detection limit to 0.04 ug/m3 (1.75 xlO-8 gr/ft3).18 Mercury
vapor concentrations were measured on- and off-site using a Jerome Model
401 Gold Film Mercury Analyzer. Both instantaneous and time-weighted
average measurements (averaged over 6 to 9 hours) using dosimeters were
obtained. On-site mercury vapor concentrations ranged from 0 to 14 ug/m3
(6.12 xlO-6 gr/ft3) for instantaneous concentrations and from 0.13 to
8.6 ug/m3 (5.68 xlO-8 to 3.76 xlO-6 gr/ft3) for time-weighted concentra-
tions.19 Off-site mercury vapor concentrations ranged from 0 to 2 ug/m3
(8.74 xlO-7 gr/ft3) for instantaneous concentrations and from 0.01 to
5.5 ug/m3 (4.37 xlO-9 to 2.40 xlO-6 gr/ft3) for time-weighted concentration
with over 80 percent of the time-weighted concentrations being equal to
or less than 1 ug/m3 (4.3 xlO-7 gr/ft3).20
To investigate the possibility that ambient mercury concentrations
at this facility could approach the inhalation health effects guideline,
which is a 30-day average concentration, dispersion modeling was performed
using emission data supplied by the company. Results indicate a maximum
30-day average concentration of 0.16 ug/m3 (6.99 xlO-8 gr/ft3) and a
minimum of 0.11 ug/m3 (4.8 xlO-8 gr/ft3).21 The difference between
30-day average modeling results and the 6- to 9-hour actual measurements
is due to such factors as differing meteorological conditions and averaging
times.
6.3.1.2.2 Other mercuric oxide battery manufacturing facilities.
Each of the other mercuric oxide battery manufacturing facilities consume
one-fourth or less mercury than the integrated battery facility. Estimated
6-13
-------
mercury emissions from these facilities range from 2 to <200 g/d (0.003 to
<0.4 lb/d).13 Emission controls used at these facilities include baghouses
and charcoal filters. Several of these plants are located in Wisconsin,
which has an ambient air standard for all mercury emission sources of
1 |jg/m3 (4.37 x!0-7 gr/ft3) on a 30-day average.
6.3.2 Alkaline-Manganese Battery Manufacturing
6.3.2.1 Process. Zinc amalgam is used in the anode of alkaline
manganese cells. The mercury consumption for the amalgamation process
at each of the seven plants manufacturing alkaline-manganese batteries
ranges from <90 to >910 kg/d (<200 to >2,000 Ib/d) of mercury.13
6.3.2.2 Mercury Emissions Potential. Mercury emissions originate
from the amalgamation of zinc and mercury and from cell assembly operations
Baghouses may be used to control particulate emissions from cell assembly.
There is no indication of control being used for mercury vapor emissions.
Mercury emissions estimates ranging from <100 to 800 g/d (<0.2 to 1.8 lb/d)
were reported by the industry.13,22,23 The range of estimates does not
correlate with the amount of mercury or controls used at each facility.
Different approaches were used by companies to estimate mercury emissions;
this may account for the variation in estimates.
Ambient dispersion modeling of the facility with the highest mercury
emission level indicates a maximum 30-day average concentration of
0.17 ug/m3 (7.43 xlO-8 gr/ft3) and a minimum of 0.07 ug/m3 (3.06 xlO-8 gr/
ft3).24
6.3.3 Leclanche Carbon-Zinc Batteries
6.3.3.1 Process. Purchased mercuric chloride or mercurous chloride
is used in a paste that is applied to a paper separator. The paper acts
as a separator between the zinc anode can and the cathode. Mercury
consumption for each of the seven plants manufacturing Leclanche carbon-zinc
batteries ranges from 2 to 19 kg/d (4 to 43 lb/d).13
6.3.3.2 Mercury Emissions Potential. Mercury emission sources include
pastemaking operations, drying ovens, and cell assembly. A baghouse may be
used to control particulate emissions, or there may be no control devices.15
Mercury emission estimates ranging from <1 to 170 g/d (<0.002 to 0.4 Ib/d)
were reported by the industry.13
6-14
-------
6.4 SECONDARY RECOVERY OF MERCURY IN RETORTS
6.4.1 Process
Mercury is recovered from batteries, thermometers, amalgams, switches.
and sludges by heating the scrap to about 538°C (1000°F) in retorts to
volatilize the mercury, which is condensed outside the retort in water-coo"
condensers. Two companies in New York and Pennsylvania and one battery
manufacturer in North Carolina operate mercury recovery retorts processing
between 64,000 and 159,000 kg/yr (140,000 and 350,000 Ib/yr) of scrap.14,2'
Several chlor-alkali companies operate small mercury recovery retorts on-s^
as mentioned in Chapter 3.
6.4.2 Mercury Emissions Potential
Mercury vapor emission sources include the condenser exhaust and vapor
emitted during unloading operations. The condenser exhaust is controlled t
a water spray at the Pennsylvania facility.25 The mercury emission level
from this facility was measured at 840 g/d (1.85 lb/d).27 Estimated mercu?
emissions for the New York facility, which uses a condenser, are <1 g/d
(<0.002 lb/d).28,29
The North Carolina battery manufacturing facility has recently
installed a water scrubber and charcoal filter to control mercury vapor
emissions from the condenser exhaust and unloading operations. This
control system is being operated on an experimental basis.14 Personnel at
the battery manufacturing facility estimate mercury emissions without the
charcoal filter in place to be 122.5 g/d (0.27 lb/d).15 No company estimat
of mercury emissions with the charcoal filter operating are available. The
recovery operations have not been operated on a normal schedule for severa"
years. It is anticipated that normal operations will resume later this
year. An emission test on the exhaust from the scrubber and charcoal
filter control system will be conducted by the company at that time.
6.5 SUMMARY AND CONCLUSIONS
Mercury emissions to the atmosphere originate from a large number
of sources in addition to those regulated by the national emission
standard. Of these sources, only battery manufacturing and secondary
recovery of mercury were investigated in this study to determine their
potential to emit mercury in a manner that could cause the ambient
6-15
-------
concentration guideline of 1.0 (jg/m3 (4.37 xlO-7 gr/ft3) to be exceeded.
The decision to investigate these two sources was based on information
about the amounts of mercury processed, the potential for air emissions,
and concern expressed by a State agency about emissions at one mercuric
oxide battery manufacturing plant.
Information on battery manufacturing was obtained for several
battery types:" mercuric oxide-zinc or mercuric oxide-cadmium, alkaline-
manganese, and Leclanche carbon-zinc. Of the five mercuric oxide battery
plants for which information was obtained in this study, it appears that
only one has the potential to cause the ambient concentration guideline
to be exceeded. This is an integrated battery manufacturing facility at
which mercuric oxide is manufactured, batteries are produced, and mercury
is recovered from scrap. Ambient mercury vapor levels (averaged over 6
to 9 hours) greater than 1 ug/m3 (4.37 xlO-7 gr/ft3) were measured on- and
off-site in a 1981 study. However, dispersion modeling at the facility
indicated a maximum 30-day average ambient concentration of 0.16 (jg/m3
(6.99 xlO-8 gr/ft3), well below the ambient concentration guideline.
Other mercuric oxide battery manufacturing facilities do not appear
to have the potential to cause the ambient concentration guideline to be
exceeded. This conclusion is based on information about the amounts of
mercury used by these plants and the estimated emission rates provided
by the industry.
A large alkaline-manganese battery manufacturing facility may use
up to 910 kg/d (2,000 Ib/d) of mercury. Mercury emission estimates
ranging up to 800 g/d (1.8 Ib/d) have been reported by industry. Ambient
dispersion modeling of the facility with the highest mercury emission
level indicates a maximum 30-day average concentration of 0.17 pg/m3
(7.43 xlO-8 gr/ft3).
Facilities that manufacture Leclanche carbon-zinc batteries use
<23 kg/d (<50 Ib/d) of mercury in the form of mercurous chloride or
mercuric chloride. Mercury emission estimates ranging to about 170 g/d
(0.4 Ib/d) have been reported. Due to the small amount of mercury
consumed, these sources would probably not cause the ambient concentration
guideline to be exceeded.
6-16
-------
Large secondary recovery retorting operations have the potential
for mercury vapor emissions to the atmosphere because of the amount of
mercury recovered. Emissions are being controlled by a water spray
tower at one facility, by a condenser at another plant, and by a water
scrubber and charcoal filter on an experimental basis at a third facility.
Emission test data for one facility and estimates of mercury emissions
from the other facilities indicate the health effects guideline will not
be exceeded.
6.6 REFERENCES FOR CHAPTER 6
1. U.S. Environmental Protection 'Agency. Background Information
Development of National Emission Standards for Hazardous Air
Pollutants: Asbestos, Beryellium, and Mercury. PB-222802. Research
Triangle Park, N.C. March 1973. pp. 71, 74, 76, 77. Docket
No. A-82-41, Document No. (II-A-3).
2. Letter and attachments from Steigerwald, B., EPArOAQPS, to Brecher, J.
Native American Rights Fund. April 27, 1973. Reply to concerns
about impact of beryllium and mercury emissions from San Juan and
Four Corners power plants on ambient levels. (II-C-1).
3. Landau, L. Mercury Sorption to Coal Fly Ash. Staub-Reinhalt.
Luft 43 1983. Nr. April 4. p. 166-167. (II-I-30).
4. Lockeretz, W. Deposition of Airborne Mercury Near Point Sources.
Water, Air, and Soil Pollution. 3:186. 1974. (II-I-4).
5. Memorandum from Sauer, M., MRI, to Project File 7703-L. May 4,
1983. Information on sludge incineration plants. (II-B-8).
6. Telecon. Atkinson, D., MRI, with Overcash, D. North Carolina
Department of Natural Resources, Raleigh. July 27, 1983. Information
on modeling analysis of Duracell, Lexington, North Carolina, plant
and mercury emissions from peat to mathanol conversion. (II-E-132).
7. Robertson, D. E., et a!., Mercury Emissions from Geothermal Power
Plants. Science. 196:1094-1097. June 3, 1977. (II-I-10).
8. Hagmann, E. L., et al. Analysis of Geothermal Wastes for Hazardous
Components, Project Summary. U.S. Environmental Protection Agency,
IERL. Cincinnati, Ohio. EPA-600/S2-83-030. June 1983. (II-A-11).
9. U.S. Department of the Interior, Bureau of Mines. Mineral Industry
Surveys—Mercury in the Fourth Quarter 1982. Washington, D.C.
March 11, 1983. p. 3. (II-I-29).
6-17
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10. U.S. Environmental Protection Agency. Materials Balance and Techno "log
Assessment of Mercury and Its Compounds on National and Regional
Bases. PB-247 000. Washington, D.C. October 1975. pp. 105-246
(II-A-6).
11. U.S. Department of the Interior, Bureau of Mines. Preprint from
the 1981 Bureau of Mines Minerals Yearbook—Mercury, p. 2.
(II-I-21).
12. Sittig, M. Resource Recovery and Recycling Handbook of Industrial
Wastes. Noyes Data Corporation. Park Ridge, New Jersey. 1975.
p. 269. (II-I-7).
13. Memorandum from Sauer, M. , MRI, to Project File 7703-1. May 19,
1983. Summary of Battery Manufacturers' Responses to EPA Information
Request. (II-B-9).
14. Memorandum from Atkinson, D., MRI, to Georgieff, N., EPA-.ISB.
July 1, 1983. Report of site visit to Duracell U.S.A., Lexington,
North Carolina. (II-B-11).
15. Meeting. Atkinson, D., MRI, with Overcash, D., North Carolina
Department of Natural Resources. June 10, 1983. Information on
Duracell U.S.A. battery facility in Lexington, North Carolina.
(II-E-123).
16. Letter and attachments from Wallis, G., Duracell Laboratory for
Physical Science, to Cuffe, S., EPA:ISB. March 8, 1983. Transmittal
of AWARE, Inc., test report—Environmental Study of Duracell U.S.A.,
Lexington, North Carolina, facility, May 1982. pp. 4-5, 4-7.
(II-D-34).
17. Telecon. Sauer, M., MRI with Wallis, G., Duracell Laboratory for
Physical Science. May 9, 1983. Information on estimated mercury
emissions and general plant operations. (II-E-117).
18. Reference 16, p. 3-14. (II-D-34).
19. Reference 16, pp. 3-7 to 3-11. (II-D-34).
20. Reference 16, pp. 3-12 to 3-13. (II-D-34).
21. Telecon. Braverman, T., EPArSRAB, to Atkinson, D., MRI. July 22,
1983. Dispersion modeling results for the Duracell U.S.A. Lexington,
North Carolina, facility. (II-E-130).
22. Memorandum from Atkinson, D. , MRI, to Georgieff, N., EPA.-ISB.
July 25, 1983. Report of site visit to Union Carbide, Asheboro,
North Carolina. (II-B-13).
23. Memorandum from Atkinson, D., MRI, to Georgieff, N., EPA:ISB.
July 25, 1983. Report of site visit to Duracell U.S.A. Cleveland,
Tennessee. (II-B-14).
6-18
-------
24. Telecon. Braverman, T., EPA:SRAB, to Atkinson, D., MRI. August 17,
1983. Dispersion modeling results for the Duracell U.S.A. Cleveland,
Tennessee, facility. (II-E-139).
25. Letter and attachment from Lawrence, B., Bethlehem Apparatus Co.,
Inc., to Sauer, M., MRI. March 29, 1983. Information on secondary
recovery operations. (II-D-41).
26. Telecon. Sauer, M., MRI, with Styk, M., New York Department of
Environmental .Conservation. March 16, 1983. Information on Mercury
Refining Co., Albany, New York. (II-E-109).
27. Letter and attachment from Lawrence, B., Bethlehem Apparatus, Co.,
to Atkinson D., MRI. August 26, 1983. Information on secondary
recovery operations. (II-D-51).
28. Telecon. Atkinson, D., MRI, with Anna, E., New York Department of
Environmental Conservation. December 30, 1982. Information on
Mercury Refining Co., Albany, New York. (II-E-24).
29. Telecon. Keller, P., MRI, with Romano, D., New York Department of
Environmental Conservation. July 11, 1983. Information on Mercury
Refining Co., Albany, New York. (II-E-127).
6-19
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APPENDIX A. LIST OF EPA DESIGN, MAINTENANCE, AND HOUSEKEEPING
PRACTICES FOR CELL ROOMS OF MERCURY-CELL CHLOR-ALKALI PLANTS
1. Chlorine cells and end-box covers should be installed, operated,
and maintained in a manner to minimize leakage of mercury and mercury-
contaminated materials.
2. Daily inspection should be made by operating personnel to
detect leaks, and immediate steps to stop the leaks should be taken.
3. High housekeeping standards should be enforced, and any spills
of mercury should be promptly cleaned up, either mechanically or chemically
or by other appropriate means. Each cell room facility should have
available and should employ a well-defined procedure for handling these
situations.
4. Floor seams should be smoothed over to minimize depressions and
to facilitate washing down of the floors.
5. All floors should be maintained in good condition, free of
cracking and spall ing, and should be regularly inspected, cleaned, and,
to the extent practical, chemically decontaminated.
6. Gaskets on denuders and hydrogen piping should be maintained in
good condition. Daily inspection should be made to detect hydrogen
leaks and prompt corrective action taken. Covers on decomposers, end
boxes, and mercury pump tanks should be well maintained and kept closed
at all times except when operation requires opening.
7. Precautions should be taken to avoid all mercury spills when
changing graphite grids or balls in horizontal decomposers or graphite
packing in vertical decomposers. Mercury-contaminated graphite should
be stored in closed containers or under water or chemically treated
solutions until it is processed for reuse or disposed.
A-l
-------
8. Where submerged pumps are used for recycling mercury from the
decomposer to the inlet of the chlorine cell, the mercury should be
covered with an aqueous layer maintained at a temperature below its
boiling point.
9. Each submerged pump should have a vapor outlet with a connection
to the end-box ventilation system. The connection should be under a
slight negative pressure so that all vapors flow into the end-box ventilati<
system.
10. Unless vapor tight covers are provided, end boxes of both
inlet and outlet ends of chlorine cells should be maintained under an
aqueous layer maintained at a temperature below its boiling point.
11. End boxes of cells should either be maintained under a negative
pressure by a ventilation system or should be equipped with fixed covers
which are leak tight. The ventilation system or end-box covers should
be maintained in good condition.
12. Any drips from hydrogen seal pots and compressor seals should
be collected and confined for processing to remove mercury, and these
drips should not be allowed to run on the floor or in open trenches.
13. Solids and liquids collected from back-flushing the filter
used for alkali metal hydroxide should be collected in an enclosed
system.
14. Impure amalgam removed from cells and mercury recovered from
process systems should be stored in an enclosed system.
15. Brine should not be purged to the cell room floor. Headers or
trenches should be provided when it is necessary to purge brine from the
process. Purged brine should be returned to the system or sent to a
treating system to remove its mercury content.
16. A portable tank should be used to collect any mercury spills
during maintenance procedures.
17. Good maintenance practice should be followed when cleaning
chlorine cells. All cells when cleaned should have any mercury surface
covered continuously with an aqueous medium. When the cells are disassemble
for overhaul maintanance, the bed plate should be either decontaminated
chemically or thoroughly flushed with water.
A-2
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18. Brine, alkali metal hydroxide, and water-wash process lines
and pumps should be maintained in good condition, and leaks should be
minimized. Leaks should be corrected promptly, and in the interim, the
leaks should be collected in suitable containers rather than allowed to
spill on floor areas.
Reference: U.S. Environmental Protection Agency. Background*
Information on Development of National Emission Standards for Hazardous
Air Pollutants: Asbestos, Beryllium, and Mercury. PB-222802. Research
Triangle Park, North Carolina. March 1973. pp. 80-83. Docket
No. A-82-41, Document No. (II-A-3).
A-3
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TECHNICAL REPORT DATA
(I'lease read Instructions on the reverse before completing)
?. REPORT NO. ' 2. "
EPA-450/3-84- 014
4. TITLE AND SUBTITLE
Review of National Emission Standards for Mercury
7. AUTHOR(S)
3. PERFORMING ORGANIZATION NAME AND ADDRESS
Office of Air Quality Planning and Standards
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
12. SPONSORING AGENCY NAME AND ADDRESS
Director for Air Quality Planning and Standards
Office of Air, Noise, and Radiation
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
3. RECIPIENT'S ACCESSION NO.
5. REPORT DATE
December 1984
&. PERFORMING ORGANIZATION CODE
8. PERFORMING ORGANIZATION REPORT NO
10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.
68-02-3817
13. TYPE OF REPORT AND PERIOD COVERED
14. SPONSORING AGENCY CODE
EPA/200/04
15. SUPPLEMENTARY NOTES "" "
16 ABSTRACT — ~~~~ — ' ~ ' '
This report presents the findings of the 5-year review of the national
emission standards for mercury. Industries subject to the existing standard
are mercury-cell chlor-alkali plants, sludge drying and incineration plants,
and mercury ore processing facilities. Information and estimates are presented
concerning processes, mercury emissions, control technology, compliance status,
and industry growth. Information is presented about other industry source
categories which have mercury air emissions, but are not regulated by the
standards.
17- KEY WORDS AND DOCUMENT ANALYSIS ^"
a. DESCRIPTORS
Mercury-cell chlor-alkali
, Sludge Drying and Incineration
Mercury Ore Processing
, Mercury Battery Manufacturing
Air Pollution
Pollution Control
Emission Standards NESHAP
18. DISTRIBUTION STATEMENT
Unlimited
b.lDENTIFIERS/OPEN ENDED TERMS
Air Pollution Control
19. SECURITY CLASS (This Keport)
Unclassified
20. SECURITY CLASS (This page)
Undflss.1f1.gd.
c. COSATI F'ield/Group
13b
21. NO. OF PAGES
68
22. PRICE
EPA Form 2220—1 .{Rev. 4 —77) PREVIOUS EDITION is OBSOLETE
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