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.
                                    3-2

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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,
                                         3-4

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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.
                                  3-5

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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

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 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

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 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

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                                   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

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     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

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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

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 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

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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

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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

-------
                    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

-------
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

-------
                                                         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

-------
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

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         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









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CATHODE




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AMALGAMATING

ARE)











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(A)
if
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DRYING










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DLtNUlNu










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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

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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

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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

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     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

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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.
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     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.
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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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