EPA-BOO/2-76-036k
February 1976                    Environmental Protection Technology Series
              DESIGN  AND OPERATING  PARAMETERS
                  FOR  EMISSION CONTROL STUDIES:
                  ASARCO,  Tacoma,  Copper  Smelter


                               Industrial Environmental      Laboratory
                                    Offiee of Research and Development
                                   U.S.
                               Research Triangle Put,         27711

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Research reports of the Office of Research and Development, U.S. Environmental
Protection  Agency,  have  been grouped into five series. These five broad
categories were established to facilitate further development and application of
environmental technology.  Elimination of traditional grouping was consciously
planned to  foster technology transfer ano  a maximum interface in related fields.
The five series are:

     1.    Environmental Health Effects Research
     2.    Environmental Protection Technology
     3.    Ecological Research
     4,    Environmental Monitoring
     5.    Socioeconomic Environmental Studies

This report has been  assigned to  the ENVIRONMENTAL PROTECTION
TECHNOLOGY series. This series describes research performed to develop and
demonstrate instrumentation, equipment,  and methodology to repair or prevent
environmental degradation from point and non-point sources  of pollution. This
work provides the new  or improved  technology  required for the control and
treatment of pollution sources to meet environmental quality standards.
This report has been reviewed by the U.S. Environmental
Protection Agency, and approved for publication.  Approval
does not signify that the contents necessarily reflect the
views and policy of the Agency,  nor  does mention of trade
names or commercial products constitute endorsement or
recommendation for use.
This document is available to the public through the National Technical Informa-
tion Service,. Springfield, Virginia 22161-

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                              EPA-600/2-76-036k
                              February 1976
      DESIGN  AND OPERATING  PARAMETERS

       FOR EMISSION  CONTROL STUDIES:

       ASARCO,  TACOMA,  COPPER SMELTER
                     by

      I.  0.  Welsenberg and  J. C. Seme

    Pacific  Environmental Services,  Inc.
              1930  14th Street
      Santa  Monica,  California  90404
      Contract No.  68-02-1405, Task 5
             ROAP  No.  21ADC-Q61
         Program Element No,  1AB013
     EPA Project Officer;  R. D, Rovang

Industrial  Environmental Research Laboratory
  Office of Energy, Minerals, and Industry
      Research  Triangle  Park, NC  27711
                Prepared  for

    U.S.  ENVIRONMENTAL  PROTECTION AGENCY
     Office of Research and Development
           Washington,  DC 20460

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                        TABLE OF CONTENTS
A.  INTRODUCTION AND SUMMARY		  1




B.  PLANT LOCATION, ACCESS AND OVERALL GENERAL ARRANGEMENT,..  I




C.  PROCESS DESCRIPTION			  7




D.  EMITTING EQUIPMENT	  10




    a. Multi-Hearth Roasters	  10




    b. Reverberatory Furnaces	,	  11




    c. Converters	  12




    d. Arsenic Circuit	  12




    e. Other Emitting Equipment	  13




E.  EXISTING CONTROL EQUIPMENT....	  13




F.  GAS SYSTEM DUCTWORK		  15




G.  SULFER BALANCE AND GAS COMPOSITION AT SYSTEM EXIT	  16




H.  GAS CHARACTERISTIC VARIATION.			  18




I.  STACK DESCRIPTION.	.	,	  28




J.  PRESENT TECHNIQUE FOR SOLID WASTE HANDLING.....	  23




K.  FOOTING AID  STRUCTURAL REQUIREMENTS  ,,,.,,.,..	  28




L.  EXISTING AND POTENTIALLY AVAILABLE UTILITIES		  23




M.  POTENTIAL NEW CONTROL EQUIPMENT INSTALLATION •PROBLEMS....  29
REFERENCES	,			  30

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                              LIST'OF'FIGURES



1.  LAND CONTOUR MAP OF SMELTER AREA.			  2

2.  ASARCO TACOMA PLANT	  3

3.  SMELTER GENERAL ARRANGEMENT	  4

4.  GAS SYSTEM DUCTWORK		.  5

5.  PROCESS FLOW SHEET ....		  8

6.  MASS DISTRIBUTION OF PARTICLES	 21

7.  MASS DISTRIBUTION OF PARTICLES	 22

8.  ASARCO-TACOMA CONVERTER OPERATION SULFUR BALANCE	 23
                              LIST'OF TABLES



1.  ASARCO-TACOMA AVERAGE SULFUR BALANCE SUMMARY	 17

2.  TACOMA SMELTER EMISSIONS ESTIMATES	 19

3.  LOW LEVEL EMISSION SOURCES AND CONTROL TECHNIQUES ,,	 20

4.  45-MINUTE SAMPLING (3 DROPS)	 25

5.  REVERBERATORY FURNACE SULFUR ELIMINATION AS A FUNCTION
       OF CHARGE RATE			 26
                                     ii

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A.  INTRODUCTION MB SUMMARY

      The purpose of this report Is to present background design
data on the ASARCO Incorporated Smelter at Tacoma, Washington in
sufficient detail to allow air pollution control system
engineering studies to be conducted.  These studies are
primarily concerned with lean S0« streams that are currently not
being captured.
      Physical layout of the smelter and surrounding area
along with existing smelter and control equipment is presented.
Ductwork that would be considered for future system tie-in
is defined.  Emissions from operating equipment, gas flow rates,
temperatures, sulfur balance and process flow sheet are
included.  Utilities, stack dimensions, footing requirements,
and solid waste handling are defined.  Available area for new
control equipment, gas characteristic variation and potential
new control equipment installation problems are discussed.
      The major uncontrolled sources of SO- at this smelter
                                          •£*
are the reverberatory furnaces and the roasters.  Available
space for installation of new equipment is limited,  A DMA
SOT concentration system producing liquid SO- and a sulfuric
acid plant are used to control S0~ from converter off gas.
B.  PLANT LOCATION, ACCESS AND OVERALL GENERAL ARRANGEMENT
      The ASARCO  Smelter is located at the edge of Puget
Sound in the towns of Tacoma, and Ruston, Washington.  An enlargement
of the USGS map, showing land contours of the immediate area is
presented in Figure 1.  Design altitude for the plant is sea
level with latitude 47° 18' and longitude 122° 30'.
      Overall plant view is shown as an artist's sketch in
Figure 2.  Smelter general arrangement is shown in Figure 3.
A schematic showing relative location of the major emitting
                                 -1-

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\
                     Pol
               \

                        SCALE 1:24000
                          o
                    1000  JOOO  3000  4000
                    _TE~--=

                     .8    0	
                                   6000  TOW FEET
             ] KILOMETER
       /  i • /
     "^ i
x^/ ]7°
  ^   / "^-f-y-
   " i*  *•" ^
     I   */ r
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   i j j
                                          D A L C 0
                                        PA S S A G B
                                                     PIERCE i


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   ASARCO  TACOIIA PLAI1T
 1MWN STACK
 2.CASTIN6 FURNACE STACK
                FURNACE
 fCOIWERTDR BUILDING
5a ARSENIC FLAWT ^.ARSENIC ROASTERS a ARSENIC
6a NORTH AhDDE STACK   b. SOUTH  ANODE STACK
 t ELECTKOLYFE WIFICATiCW PLANT
8 ROASTER SUILP1M-
d. METALLIC ARSENIC PLAPf
                                                        Figure  2

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Figure 3.  SMELTER GENERAL ARRANGEMENT
(Located in Pocket Inside of Back Cover)

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             Outlet Sampling Port
                               H Cottrell
                                   Inlet Sampling Port
                                               4 i 3 | 2 I j1   Waste Heat Boilers
„ . .  . .   280 tcl   "
io liuid    	'   Spr
                                                                                             FLUE DIHEHSIONS
Flue
No. 1 Brick Flue
(A-B)
No. 2 Brick Flue
CC-W
Junction Tower (E)
Reverb Flue
(G-H)
Eoaster Building Flue
d-J)
,,„_, 	 *-
L
450'
550'
26'
165-10"
120'
H
24'
24'
43'-4"
20'-6"
12*
W
20'
20'
18'
27"
12'-1" !
|
                                                                                   Note: Roasters 1-6 10,000 SCFM/Roaster

                                                                                        Roaster 7-10 15,000 SCFM/Raaster




                                                                                        x Denotes Water Sprays
                                                                                  GAS  SYSTEM  DUCTWORK
                                                                                   ASARCO /Tacoma Branch
prepared  July, 1975
                                                                                   PACIFIC  ENVIRONMENTAL  SERVICES
                                                                                                                       Figure

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equipment with connecting duct work is given in Figure 4.
The primary particulate emission sources are the crushing and
screening operations, the roasters, the reverberatory furnaces and
converters.  The primary sources of sulfur dioxide are the
roasters,  reverberatory furnaces and the converters.
      This plant, from a system and equipment standpoint,
is one of the most complicated copper smelters in the United
States.  It not only includes the conventional copper roasters,
reverberatory furnaces and converters, but also additional
arsenic ore processing equipment and sulfuric acid plant and
a liquid SO,, plant for SO™ control and other refinery equipment
for producing nickel sulfate, dore and sodium selenite products.
There are ten multi-hearth roasters, two reverberatory furnaces,
four converters, and arsenic trioxide and a metallic .arsenic
plant.
      The smelter portion of the plant consists, of the coarse
ore and concentrate handling and crushing equipment, ten
Herreshoff roasters, two reverberatory furnaces, four conver-
ters, and three anode furnaces.   Arsenic processing equipment con-
sists of six Godfrey roasters (four usable), arsenic
trioxide settling kitchens, arsenic trioxide storage and a
metallic arsenic plant.  This smelter has extensive  varied
equipment, primarily to handle a wide range of ore types
since it is a custom smelter.
      The pollution control equipment consists of five cyclones
for the ore handling equipment along with coolers, spray chambers
and precipitators for conditioning the converter and roaster
gases going to the sulfuric acid plant and the liquid SO- plant.
All  tail gases  from the  acid plant  and  liquid  SO  plant  go
to the stack.
      The gases from the  roasters and reverberatory furnace pass through
electrostatic precipitators before going to the main stack.
                                -6-

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        Figure  3  showing  the overall plant arrangement  indicates  that
  there  is  relatively  little available  area  for  Installation of con-
  trol equipment.  There  is a possibility of the use  of the Tacoma
  Tide Lands  area on the  easterly side  of the smelter,  and some
  smaller areas adjacent  to existing equipment.  The  50" x 100'
  nickel plant  will be torn down in the near future and this site
  could  also  be used for  new equipment  installation.

  C.  PROCESS DESCRIPTION
        The smelter flow  sheet diagram  is shown  in Figure 5,  The
  plant  feed  in the form  of ore and concentrate  goes  to the Herreshoff
  multi-hearth  roasters.  Byproducts containing  arsenic are fed to the
  Godfrey roasters.  Analysis of the heavy metal and  sulfur content of
  a typical roaster charge during a recent test  period  is shown in the
  following :
                Cu    As    Sb    Hi    S     Cd    Hg'    Se
1/20/75 1.0    22.9  3.3   0.3   0.11 29.6   0.02   0.0051 0.024
1/21/75 1.0    23.7  3.8   0.4   0.04 30.0   0.02   0.0041 0,018
1/23/75 1.1    21.9  2.8   0.3   0.04 28.8   0.02   0.0038 0.015

       The arsenical material after Godfrey roasting will pass as
 calcines to the fine ore bins for mixing and then to the Herreshoff
 multi-hearth roasters.  The hot calcines from the multi-hearth are
 taken by larry car to one of two reverberatory furnaces where they
 are converted to matte containing 35-45% copper.  The matte is then
 poured into ladles and taken by crane in the molten state to charge
 the converters.  Slag from the furnace is sent to the dump.

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                                                                                                                                      As Ship
                                                   ! Ore and Concen-
                                                    trate Crushing
                                                   ] and Handling
                                                   ! w/5 cyelortPR
                                                    82,000 SCFM
                                                            40,000 - 100,000 SCFM
                                                                  2500°F
Sludje   Hickel
EecyciLe
        Plant    Acid)   Plant    '51ag
                                                   0 to 100,000
                                                      SCFM
                                                     fl 500°F
                                       Vent to Freclpltators
                                       During Convert Rollout
        Ship
Dore
Ship
   I
   *
 Sodium
Selenite
  Ship
                                                    .Residue to Roasters
                                                     or Ore Storage Bins
                                                            PROCESS  FLOW  SHEET
                                                                            ASARCO  /Tacuma Branch
prepared  July ,1975
                                                                                                PACIFIC  ENVIRONMENTAL   SERVICES
                                                                                                                                           Figure 5

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      The converters produce a blister copper which is approximately
98-99% pure.  This material is transferred by ladle in the molten
state to the anode furnace where some minor impurities are removed
by fire refining and the molten material cast into anodes,  The
anodes are then taken to the electrolytic refinery where they are
reduced to electrolytic copper as cathodes or product copper.  The
electrolyte from the refinery is passed to the nickel plant which
produces NiSO. for shipment, sludge which is recycled, and black
acid which is sent to the dore* plant.  Refinery slimes are sent
to the dore' plant which produces dore1 for shipment and niter slag
that is sent to the selenium plant.  Sodium selenide produced in the
selenium plant is shipped and the plant residue is recycled.
      The arsenic circuit consists of the arsenic charge bin which
charges feed material to the Godfrey roasters for gasification of
the arsenic material.  The gasified arsenic material is then passed
through the arsenic settling kitchens where the arsenic trioxide
is condensed in the various sections.  There are three arsenic
kitchens, one ten chamber and two fifteen chamber baffled enclosures.
      The nickel plant  produces nickel sludge which is returned to
the smelter and nickel sulfate which is shipped for further pro-
cessing to other plants.  Black acid is also produced and sent to the
dore' plant.  The dore1 is shipped for further processing.  Slag
produced from the dore' plant is sent to the selenium plant which
produces sodium selenite for shipment and residue which is passed
back to the roasters or ore storage bins.
      Gases from the multi-hearth roasters pass to an electrostatic
precipitator and out the stack.  Dust from this precipitator is
recycled.  Gases from the reverberatory furnaces are sent to an
electrostatic precipitator and out the stack.  Gases from the con-
verters are sent either to a 200 TPD liquid SO^ plant which produces
liquid S0_ or to a 200 TPD sulfuric acid plant.  Gases from the con-
verter are passed to a multicyclone before going to individual gas
cleaning circuits for the liquid SO,, or the sulfuric acid plants.

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Offgases from the acid plant and the liquid SCL plant go directly
to the stack. Converter  gases  can  also be bypassed  directly  to  the
precipitator and then out the stack.
      The gas cleaning circuit for each plant (the  liquid S07 and
sulfuric acid plants) consists of  spray chambers, precipitators, scrubbers
and mist precipitators to prepare  the gases for either acid or liquid
SO- production.  Gases from the roasters or arsenic settling kitchens
  £•
pass to precipitators and then out the stack.  Gases from the re-
verberatory furnace pass through waste-heat boilers and then through
precipitators and out the stack.   Some of the gases from the conver-
ters during rollout are collected  in the converter hoods and passed
by a separate fan-blown system through the precipitators and then
to the stack,  Offgases from the acid plant and liquid SO  plant are
passed directly to the stack,
      Dust from the precipitators upstream of the liquid SO- and
acid plants may contain lead which is shipped to a  lead smelter for
further processing.
      Because of the nature of the ore received by this smelter
from sources such as the Philippines, Arizona or other parts of the
world, a wide range of products can be manufactured.
      Nickel sulfate, dore', sodium selenite, copper cathodes,
copper shapes  sulfuric acid, arsenic trioxide, arsenic, lead dust,
and liquid SO- can be produced.
      Temperatures, volume flows and S0? percentage are shown on the
flow sheet, Figure 5.
D.  EMITTING EQUIPMENT
a.  Multi-_He_arth Roasters
      There are ten Herreshoff multi-hearth roasters arranged in a
double row as shown in Figure 4.  Roaster hearth area is 1345 square
feet with dimensions of 19 feet diameter by 25 feet high.  The top
                               -10-

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of the roasters is approximately 40 feet from ground level,
      There are usually five roasters used at one time.  However,
there may be as many as six and as few as none in operation at any
particular time.  Dampers are located in the roaster uptake duct
to isolate units not in operation.  Roaster ore is heated to
approximately 900 F.
      As is normally encountered with multi-hearth roaster,
considerable leakage is present throughout the associated duct-
work as well as the units themselves.  This results in dilution
air entering the system and reducing the concentration of pollutants
such as SO,,.
      The capacity of each roaster is 1200 tons per day.  Eight
loads per hour is considered the normal production rate.  One
load weighs approximately 6.5 tons.
b.  Reverberatory Furnaces
      Two reverberatory furnaces of approximately 1200 TPD capacity
each are installed.  No. 1 has dimensions of 30' wide by 110' long
and No. 2 has dimensions of 32* wide by 110' long.  The draft for
each furnace is generated by a steam turbine driven fan.  Four Wag-
staff guns are used to feed each furnace at the side.
      Most of the time, only the No. 2 reverberatory furnace is used.
Within the last two years No. 1 has only been used for a total time
of two months.
      A negative .02 inches of water pressure is maintained auto-
matically in the reverberatory furnace during normal operation.
During charging of the furnace the control damper is opened wide by
manual overide to minimize pressure surges.  The fuel supply is also
cut off for a present time of approximately 30 to 40 seconds to
minimize the occurrence of positive pressure.

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      Maximum fuel consumption for the reverberatory furnace is
180,000 CFH of 1030 BTU per cubic foot gas.  An air to fuel ratio
of 10 to 11 is used for furnace firing.  There are three waste-
heat boilers downstream of the two reverberatory furnaces, one on
#1 and two on #2.  Each of the #2 furnace boilers has a rating of
1000 horsepower and the $1 has a rating of 1890 horsepower.  Gas
temperature is reduced from 2500 F to 700 F - 800 F across the
waste-heat boilers.  Approximately 35 GPM of water is used in each
boiler.
c.  Converters
      Three Peirce-Smith converters have dimensions of 13 feet
diameter by 30 feet long and one Peirce-Smith converter 11 feet
diameter by 26 feet long.  Normally only three converters are used
at any one time.   Blowing is limited to no more than two at any
one time and generally a finish blow on one only will be conducted.
      Normal converter cycle takes 12 hours.  Total converter opera-
tion seldom exceeds 40 hours per day and has a range of 25-40
hours per day.  The blowing rate will vary from 17,000 SCFM to
25,000 SCFM.  With dilution air the volume flow from each converter
through the hood during the blowing periods is approximately 38,000
- 40,000 SCFM.
      Sulfur dioxide of up to 10 percent has been measured immediately
downstream of the converter opening at the hood.  Average SO  per-
centages are in the 3-4 percent range,
d.  Arsenic Circuit:
      The arsenic kitchens are rectangular shaped, brick or concrete
ovenlike structures divided into 10 or 15 chambers.  The gases are
continuously passed at very low velocity through each chamber
resulting in gradual cooling by radiation.  The arsenic condenses
at approximately 400 F and is collected in the intermediate chamb«
in the kitchens.  The condensed arsenic trioxide is removed
                               -12-

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periodically from the settling kitchens and placed in storage.
This material is either shipped as is or reduced to metal in the
arsenic trioxide reduction plant.
e.  OtherEmitting Equipment
      Material handling in the feed preparation area during crushing
or preparation operations generates particulates.
      The anode furnace generates small quantities of S09 and
particulates.
      Leaks in ducts and at other pieces of equipment can generate
SO- and particulates.
      Ladles holding matte and slag will produce visible fugitive
emissions.  The liquid SO  plant and the acid plant will produce
small quantities of S0? in the offgas.
      Dust from the precipitator handling the reverberatory furnace
and roaster gases is the major source of arsenic processed in the
arsenic kitchens.  The converter dust obtained from the precipitator
handling the converter gases is also processed but since it has
a lower percentage of arsenic this material is recycled through the
arsenic roasters and then shipped to another plant for lead recovery.
The converter dust is processed at separate times through the
arsenic circuit.  The arsenic in the charge is   eliminated 20%  from
the roasters, 60% from the reverberatory furnace, 10% out of the
matte and 10% out of the reverberatory slag.
E.  EXISTING CONTROL EQUIPMENT
      The coarse ores and concentrate handling and crushing area
has five cyclones for particulate collection.
      Three electrostatic precipitators are used for brick flues
No. 1 and No. 2 to collect particulate before the gases from all
collection points in the smelter pass out the single main stack.
Since the two main brick flues join together and automatically
balance the flow, there is no complete separation between roaster and
                               -13-

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reverberatory furnace offgases.  However, the two precipitators
in brick flue No. 1 (Fig. 4) generally treat the roaster offgases
and the single precipitator in brick flue No. 2 treats the reverbera-
tory furnace offgases.  There is no S0_ collection for the roaster
or reverberatory furnace offgases.  Water and sulfuric acid are
sprayed into the flues upstream of the precipitators for conditioning
and cooling.  The gases that join at the roaster chamber and rever-
beratory flue are conditioned for precipitation by adding small
quantities of SO,, taken from the acid plant,
      The precipitator in brick flue No. 2 consists of five sections
with six units in each section.  The overall dimensions are 7T9" x
14' 0" x 72'0".  The upstream pipe precipitator in brick flue No. 1
has two sections of 4-1/2 units each consisting of 84 - 12" x 15' x 0"
pipes per unit.  The downstream precipitator in brick flue No. 1
is a plate-type of five sections, each section having four units each
8'6" wide x 7'6" long x 12'0" high.  The precipitators are designed
to handle a total volume flow of 345,000 ACFM.
      The single contact acid plant was originally designed in 1950
for 100 TPD at 3% SO .  It has been enlarged to the 200 TPD capacity
at 5% SO  and is capable of handling 23,000 SCFM.
      Acid production record in tons:
              Year                         Tons H SO,
              1969                           38,379
              1970                           37,485
              1971                           40,154
              1972                           22,230
              (first half)
      The acid plant precipitator is designed to handle a volume
flow of 34,000 ACFM.
                               -14-

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      The liquid S0? plant processes up to 45,000 SCFM of the con-
verter gases.  This system uses dimethylaniline (DMA) for absorbing
the gaseous S0_ and then regenerating by stripping with steam.  The
concentrated SO^ is produced as a 100% gas.  It is liquified by
compression and is then stored under pressure.  A description of the
DMA process is included in Appendix A,
      The DMA concentration plant contains 20,000 gallons of DMA
which is passed between the pregnant tank and the stripped tank.
When there is no SO- being generated by the converters, the system
operation can be cut back so that very little DMA is processed.
      Some of the liquid SO  is shipped to the east coast under a
contractual agreement that ASARCO has with a chemical firm.  This
long shipping distance results in a net cost to ASARCO for S0_ pro-
duction.  The price of SO. must be competitive with that produced
from elemental sulfur burning,
F,  GAS SYSTEM pUCTWORK
      A plan view of the interconnecting ductwork between the
roasters, reverberatory furnaces, converters, acid plant, liquid
SO  plant and the stack is shown in Figure 4.  Gases from any one
of ten multi—hearth roasters pass into the roaster building flue,
then to the roaster chamber or settling flue and then to the junction
with the reverberatory furnace flue.  Gases from the reverberatory
furnaces pass through waste—heat boilers, then to the reverberatory
furnace flue.  The No. 1 brick flue takes most of the gases from the
roaster building and No, 2 brick flue takes most of the gases from
the reverberatory furnaces.  However a crossover link is installed
to allow system pressure balance.  The draft is obtained from the
563 foot high main stack and is 2" W.C. at the base.  Duct dimensions
are shown in Figure 4.  Gases from the converter hoods are drawn by
two hot gas fans and allowed to pass either to the liquid S0~ plant,
the sulfuric acid plant or to the stack.  An additional line is used
to provide SO,, from the acid plant to condition the gases for the
final precipitator treatment.
                              -15-

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      A separate vent system connected to the converter hoods, is
used during converter rollout to minimize fugitive emissions during
the non-blowing phase.  Not all gases enter the hood during this
phase because of geometrical considerations.  The duct is connected
to the brick flues which pass this gas out the tall stack.
      Elevations of principal ductwork are as follows:  (All eleva-
tions are to the bottom of the flue).
            No, 1 Brick Flue         67« - 150'
            No. 2 Brick Flue         67f - 150'
            Roaster Chamber Flue            54'
            Roaster Building Balloon        65'
            Flue
            Reverberatory                   50'
      The acid plant and SO™ plant offgases are vented to the main
stack downstream of the precipitators.
G.  SULFUR BALANCE AM) GAS COMPOSITION AT SYSTEM EXIT
       Typical _Sulfur Balance Data - TPD Sulfur
       From ore concentrates charged        270
       To 100% sulfuric acid produced        39
       To liquid SO  produced                71
       To slag                                6
       To other waste (not emissions)         2
       To SO, emissions                     152
      The above are recent typical data based on monthly measure-
ments. Reference 2.  Table 1 summarizes representative sulfur
balance by emitting equipment.
      S09 concentration at the outlet of the multi-hearth roasters
was measured to be 1.5% with 3.5% to 5,0% water.  SG_ concentration
at the outlet of the precipitators in brick flue No. 1 was 0,6%,
Reference 3.
                               -16-

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            TABLE 1
         ASARCO/TACOMA
AVERAGE SULFUR BALANCE SUMMARY
Sulfur
Input
TPD-S
300
Roasters
(Uncontrolled)
%so2
1.5
TPD-S
60
Reverberatory
Furnaces
(Uncontrolled)
%so2
1,0
TPD-S
84
Converters
(Partially Controlled)
%so2
3 to 4
{up to
10%)
TPD-S
141,6
Slag and
Solid Waste
(Controlled)
TPD-S
4.8
Fugitive
Emissions
(Uncontrolled)
TPD-S
9.6
(By difference)
Sulfur j
Captured
(Slag and Acid Plant)
TPD-S
158.4

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      Suspended particulate in tons per year, and SO  in  tons per
                                                    x
year for the years 1971-1975 are shown on Table 2, Reference 4.
      Low level sources near the plant that have had some control
are listed in the following Table 3  (Reference 6),  Dates show
the date of control.
      Figure 6 and Figure 7 show mass distribution of particles
upstream and downstream of the precipitator in brick flue No. 1
which carries most of the gases from the roasters.  As can be seen,
the precipitator takes out a major portion of the . Ijj. to 10u.
material but does not effect the less than . Ijj particles to as
great an extent.  Mass mean diameter at the precipitator outlet
has been determined to be . 12 u. , std. dev. ,162 jj. (Reference 6).
      Particulate emissions from the tall stack (from all plant
equipment) are estimated by PSAPCA and ASARCO as follows:
                                                Material T/Y  AS2°3 T/Y
                Total Part. T/Y   AS20  T/Y       Under 3.2u  Under 3.2
                                                 (Reference 6)  (Reference 6)
ESP ASARCO
(Estimate)            150            80               99         52  (3)
PSAPCA                191           102              140         72  (3)
(Estimate)
      The chart, Figure 8, shows the sulfur captured by month during
1974 and 1975 from the converter gases related to sulfur input in
the matte.  This shows the relative sulfur captured in the slag,
liquid S0_ and sulfuric acid and indicates the major improvement
obtained with the liquid S0_ plant.
H.  GAS CHARACTERISTIC VARIATION
      The SO- concentrations in the offgas from  the reverberatory
furnace will vary significantly depending upon the charge rate and
the various sulfide materials contained in the charge.  The normal
                               -18-

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                                             Table  2
                                TACOF1A SMELTER  EMISSIONS  ESTIMATES
PARTI CULATE TONS/YR
YR,

1971
1972
1973
1974
*1975

TALL STACK
ARSENIC
TRIOXIDE'
506
228
176
164
80

CADMIUM
3,4
1,6
1,2
0,6
0,2

TOTAL
970
438
335
308
150

LOW LEVEL
As2o3
296+
281+
• 266+
167+
90,+

CADMIUM
2,0+
1,9+
1,8+
1,5+
,98+

TOTAL
1285+
1218+
1145+
967+
682+

SOX TONS/YR
m

164,600
156,000
148,000
117,900
99,600

d&

6814
6460
6127
3414
3400

i-O
1
       + INDICATES  THAT THERE ARE LOW LEVEL EMISSIONS WHICH.HAVE NOT BEEN MEASURED OR ESTIMATED,
       * 1975 ESTIMATE BASED ON ASARCO REPORTS FOR JANUARY AND FEBRUARY,
                                                                                Reference 6

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TABLE 3. LOW LEVEL EMISSION SOURCES Date of
AND CONTROL TECHNIQUES Control

1.
2.
3,
4.
5.
6,
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
Wind Blow Dust from ASARCO Property
In-Plant Road Dust
Improve Matte Ladle Loading Hood
Arsenic Storage and Loadout
Dust from Converter Flue Unloading
Conveyor for Arsenic Feed Plant
Larry Car Covers
Reverb. Furnace Slag Launder
Reverb, Furnace Charge Guns
Flue Dust Handling
Converter Fugitive Emissions
Ore Roasters Fugitive Emissions
Slag Bumping
Gravel Roads Outside Plant
Wind Blown Dust Outside Plant
Sealing Arsenic Building
Anode Furnaces
Reverb. Furnace Slag Launder for Converter
Minimum Blow on Converters
TallStack
Metallic Arsenic Plant
Original Cottrells (ESP)
Acid Plant
New ESP Rappers
New ESP Voltage Regulators
Use of SOo for ESP Dust Conditioning
Liquid SO? Plant
Roaster SO? Control
Bagtiouse for Arsenic Plant Flue
Ventillation As Pulling for Kitchens
6/73
6/73
2/74
2/74
3/74
4/74
11/74
5/75
2/75
5/75



7/75
7/75


4/76
12/75


1917
1950
12/71
12/73
7/74
7/74



-20-

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Mass distribution of particles
upstream of the  #1-electrostatic
precipitator  (assuming particle
specific gravity = 5.865).
 Legends
  0  test 3, Nelson impactor
     fest *f» Nelson, impaetor
     Test *f, UW Mark II irapactor
     Test 6,  Nelson impactor
                                            ^
                                                                    10

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               Mass distribution of particles
               downstream of the  #1 electrostatic
               precipitator (assuming particle
               specific gravity = 3.865)
                                                                       'Figure  7
               Legend;

               O  Test 1, Nelson impactor

                   Test 2, Nelson iaspactor B.S P

               D  Test 2, UW Mark II impactor
                   Test  5i  Nelson impactor (baghous^
               Q  Test  ?t  Nelson impactor (baghoueef—

      L~LjJ4  •
                                    ,.| 'I TV..-.. --:.-. :•:..;•:. 1-.. I

,0001
                                               -22-
                                                                                    10

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                                                       Figure  8
            ASARCO - TACOMA

   CONVERTER OPERATION   SULFUR BALANCE
Tons Sulfur In:

leyerb. Matte chgd,
to Converters
                                                            Liquid  S0~
                                                            Converter Slag
FMAMJJA   SO'NDJFMAMJJASOND
                           -23-

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or average charge rate into the furnace is four loads per hour.
However, this can vary between two and eight loads per hour.  This
"variation is a result of intermittent pollution control and smelter
operations and can be controlled only to a limited extent.  Table
4 shows the effect of variation in charge or dropping rate into the
furnace on the percent S0? concentration in the offgas.  These
measurements (Reference 5} were taken primarily in the steel flue
immediately downstream of the No. 2 reverberatory furnace.  The
firing rate will also have an affect on the percent S0?.  Table 5
shows a variation from .16% SCL up to 1.52% S0«.  This occurred over
a volume flow range of 33,338 SCFM to 54,600 SCFM.
      Table 5 further shows the potential variation in SO  concen-
tration.  For the date of 2/16/70 the average percent SO,, between
drops was 1.0%.  This occurred at a charging rate of 6 loads per
hour.  Maximum peak percent S0_ during this same period was measured
as 13.0% but there is considerable question as to the accuracy of
this number.  The average of peak values for this same period (1
hour) was 6.5%.  Thus, it can be seen that between at least 1.0%
and 6.5% can be encountered over a relatively short period of time.
The second set of data in Table 5 had a charging rate of 8 loads per
hour and indicates less of a variation but still shows a peak of
5.0% to an average between drops at .75%,
      From these data it can be said that peak S0_ may vary between
7-13 times the average percent S0_.  Any control system must be
designed with this variability in mind.
      SO,, concentration in the converter offgas also varies con-
siderably because of the batch nature of the operation.  Also, the
variation in actual metallurgical operation between slag blows and
copper blows will cause a variation in percent SO-.  Between blows
the converter may be rolled out for slag pouring or material
charging.  When the converter is not blowing the hood above the
converter collects the gases and passes them to a separate vent
system.  See Figure 4.
                               -24-

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          Table 4.
45-Minute Sampling (3 Drops)
Date
/21/70
121
127
713
/16
ii
tt
ii
!!
rt
ii
(i
ii
n
ii
712
713
713
Dropping Rate
Loads/Hour
8
7
7
5
2
6
6
4
5
5
4
4
4
4
6
5
6
6
% S02
Shell Keich














-
1.09
1.55
0.82
1.07
0,16
0.26
0.49
0.15
0.21
0.21
0.45
0.21
0.28
0.30
0.43
0.45
0.32
1.64
1.21
1,52
1.40
Volume
Std. cfm
_
-
-
-
37,586
39,439
33,338
-

-
-
-
-
49,700
54,600
52,000
48,700
Tons S
Elim./Hr.
_
-
-
-
_
0.22
0.23
0.41
-

-
-
-
-
2.23
1.81
2.21
1.87
Sample Location
#2 Reverb. Uptake (Dpstrm. W.H.B.)
#2 Reverb. Steel Flue (Dwnstrm. W.H.B.)
ir
II
II
it
II
n
II
II
II
II
II
II
II
II
II
"

-------
                                        Table  5.
                         Reverberatory Furnace Sulfur Elimination
                              As A Function  of Charge Rate
Date
2/16/70
It
11
9/10/71
rt
it
Dropping Rate
Loads /Hour
6
6
6
8
8
8
%
so2
1.0
13. GO)
6,5
0.75
5.0
4.0
Volume
Std.- cfm
51,300
51,300
51,300
51,000
51,000
51,000
Ton S
Elim. /Hr
1.41
18.30
9.14
1.04
6.98
5.59
*
Sampling Period
Average between drops
Max. Peak during drop
Average Peak during drop
Average between drops
Max. Peak during drop
Average Peak during drop
Sampling was done in #2 Reverb.  Steel Flue

-------
      The attempt is always made to maintain at least one converter
blowing gases into the system at any given time.  Usually a converter
will be provided with 18,000 - 20,000 SCFM to the tuyeres.  An
additional 100-120% of dilution air is generally estimated to be
added to this gas flow resultiag in a total gas flow from each
converter in the range of 35,000 — 40,000 SCFM.  When a converter
is blowing there will usually be approximately 38,000 SCFM and an
SO- content in the range of 4,0 to 4,5%,
      Because of the above, the gas volume flow from the converter
line to the control system acid plant and liquid S0« plant can
vary over a wide range from maximum to zero.  Stored liquid S09
can be fed to the acid plant when the smelter is not generating
a sufficient quantity, thereby allowing the acid plant to operate
on a continuous basis to minimize startup inefficiencies and
corrosion.  Because of contractual commitments, ASARCO is generally
not able to operate in this manner.
I.  STACK DESCRIPTION
      The 563-foot high stack has a top diameter of 24 feet.  The
top of the stack is located 713 feet above sea level.
      Inlet temperature at the bottom of the stack is 185 F.
      Stack construction is brick and mortar with an acid brick
lining.
      The acid plant and liquid SO,, plant offgases are ducted to the
main stack.
      There is a preheater used to heat the gases going up the
stack.  When the preheater is not used a temperature of 150 F will
be reached 200 feet up the stack.  When the preheater is used, a
temperature of 250 F is reached at the 200-foot elevation.
                               — 27—

-------
J,  PRESENT TECHNIQUE FOR SOLID-WASTE HANDLING
      Slag is sold for sandblasting, roof  granules or portland cement
aggregate.  Dust taken from the dust collection devices are recycled.
Lead containing dusts are shipped to the Helena, Montana smelter for
processing.  Dusts high in arsenic are processed through the arsenic
circuit.
K,  FOOTING AND STRUCTURAL REQUIREMENTS
      Most of the smelter is constructed on fill slag and some saw-
mill wastes are the primary fill constituents.  Pilings, installed
by drilling and driving, are required on 3-foot centers.  City of
Tacoraa local codes apply.  Seismic zone 3, wind load 25 PSF, and
snow load 15 PSF are used for design.
L.  EXISTING AND POTENTIALLY AVAILABLE UTILITIES
      There is an abundant water supply and it is expected that any
new control equipment can be supplied with the existing system.
      Future increases in gas usage as fuel are unacceptable due to
the decreasing availability of natural gas.  There are no additional
loads that can be supplied to the gas system.  Direct-fired and
waste-heat boilers provide steam for compressed air, heating and
S0_ DMA stripping.  The #1 furnace waste-heat boiler is rated at
1890 HP and 65,205 Ib/hr of steam and the two #2 furnace waste-heat
boilers are each rated at 1000 HP and 34.500 Ib/hr of steam.  Tacoma
City Light Company provides electricity required.  The available sub-
station is now operating at approximately 75% capacity.  There is an
additional 5,000 KVA capacity available.
M.  POTENTIAL NEW CONTROL EQUIPMENTINSTALLATION PROBLEMS
      One of the major problems at this particular smelter would be
to find space for additional control equipment near the emission
source.  The Tacoma Tide Lands area would appear to be the most
logical for installation of any extensive control equipment.  As can
                                -28-

-------
be seen from Figure 3 the plant area is fairly well crowded with
buildings, flues and equipment.  The area adjacent to the street
is also a potential space for control equipment, though it also
is some distance from the major emission sources.  The area along
brick flue No, 1 adjacent to the metallic arsenic area is also a
potential space for control equipment.  The smelter is obtaining
to obtain a. permit to fill ten acres with slag up to the 1961
inner harbor line which could be used but at additional  fill
expense.  The 50' x 100' nickel plant will be torn down in the
near future making this site available for new equipment.
      Tests with a pilot baghouse were performed to compare bag-
house collection efficiency with electrostatic precipitator
collection efficiency.  The tests indicated that the baghouse was
approximately 25 times better at collecting particles less than 1
micron.
                                -29-

-------
                          REFERENCES
1.  Discussion with Mr. C.H. Randt, Assistant Manager ASARCQ Tacoma
    Plant.
2.  ASARCO sulfur balance, March 1975,
3.  Puget Sound Air Pollution Control Agency data taken using
    Ritagawa tubes and Umgard pump.
4.  ASARCO Data, 4-14-75.
5.  ASARCO data.
6.  Puget Sound Air Pollution Control Agency data and calculations.
                               -30-

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      19SO
INDUSTRIAL AND  ENGINEERING  CHEMISTRY
                                                                                                           22S3
 •jture combustion.  In this case, a preheat of over 500* C, In
.. p$ would be necessary to maintain the required temperature
. ;]g reduction furnace.
 .toco was considering the installation of a commercial 35-tori-
.nhy sulfur unit at Garfidd in 1944.  By that time, however,
.. leasehold requirements of Salt Lake City for natural gas dur-
I ide winter months became so heavy that existing pipe lines
«IJ not supply  this demand and at  the same time carry the
 iiistris) load. Tlie project wns therefore shelved.
                                                LITERATURE CITED
                               (1) Fleming, E. P., and Fitt, T. C. (to American Smelting and Re-
                                    fining Co.), U. S. Patent 2,270,427 (Jan. SO, 1942).
                               (2) Ibid,. 2,388,259 (Nov. «. 1945),
                               (3) Ibid,, 2,431,230 (Nov. 18, 1947).
                               (4) Pulton, Chan, H.,  U. 8. Dept. Interior, Bull. 84 (1915).
                               (5) Leeds & Northrup Co., Philadelphia,  Pa., private communi-
                                    cations.
                               (6) Lepaoo, E., IKD. EKO. CHEM., 30, 02 (1938); 32, 810 (1040).
                               (7) Young, S. W.,  Trans. Am. Intt. Chem. Engrt., 8, 81 (1915),
                               RICEIVEB March 27, 1950.
   LIQUID   SULFUR  DIOXIDE   FROM

             WASTE  SMELTER  GASES
                       Use of  Dimethylaniline as Absorbant

                          EDWARD P. FLEMING AND  T, CLEON FITT
                      American Smelting and Refining Company, San Francisco, Calif.
 MI1E American Smelting
 I and Refining Company
 4 for the past 30 years,
 "rn engaged in investignt-
 i various methods for re-
 wring sulfur dioxide from
 '•i  waste  smelter gusos
 •A< tho twofold objective
 • muiinizing sniolce com-
 iteand perfecting aproe-
 ••*'hat could compete with
 "sustnne  in  the  sulfitc
 ..ij»r pulp industry.  Over
 '-i period, pilot planta of
 )m 1 to  15 tons' capacity
 :-i'« been  operated, using
 '•M Haenisch-Schrooder
 '•ilcr-absorption   process
 '), direct compression of
 ''''•grade converter gaa in u
 '•••"tt-pcwlay pilot plant (fl),
 :!* ammonium sullitfi-binul-
*'-ii cycle  (4),  the Lurgi
 >«lplii<]uic" praeeas uwing
V'lklmo in water suspension (0), and finally tho Asarco process
 ••"lEiiiiiictliyliuiilino (I, S),  Laboratory experimontnl work wiii
 "> I'liwluctud on other reagents, particularly Imperial Chemi-
 -'ibiwic aluminum sulfatc (/, 7) and I,urgi's toluiler to orMtrato and also
  ''J<:>! KIP proccivi cynln of operation, patented by American
 •••iiiH! !>'id Er-finiriR Oompany, i«:rmitted material savings in
 •i.'Xit- lo:^-i, Htenni cmifluinptioti, and  labor cost as compared
 •'••' U'i: I,urj{i cycle as operated in 1'luropo by MetuHgescllHchaft.
 "*  s'llphidiixs  Kystem a-s developed  by MetullKesellBcliaft
  •' f< >[ of .separate unite for alworplion of nulfur dioxide, recov-
  .' "f xylidiijc, vujwr in tiwd Kwubber Holutwm, ri'.gnueration of
 .'; inn sulfate with H«lu ;«,h and vouling to 2° O,, unit (k-.wption
 • iliiir- di(K\'wlu.  These various oporjitionn involved considftr-
•'"••' n-i'pf.nl losa, excessive labor, and high steam coiiNumntion.
                               paper reviews tha various pilot plant investigations
                         conducted by tha American Smelting and Refining Com-
                         pany during the past 30 year* with tha object of perfecting
                         a process that could produce liquid sulfur dioxide commer-
                         cially from waste smelter gases* Processes developed along
                         these lines in Europe are briefly discussed and reasons given
                         £01* the selection by American  Smelting and Refining of
                         anhydrous  dimethylaniline  as  its  preferred  reagent.
                         The novel features of process system and plant construc-
                         tion are described in detail fay reference to the flow diagram
                         of the 20-ton plant installed September 1947, in the com-
                         pany's load smelter at Selby, Calif.  The benefits of the im-
                         proved  system of operation, as  compared with the proce-
                         dure followed in European plants, are emphasized; among
                         these are high purity of product and facility of operation.
                         Basic data  aa indicated by 1949 operations at Selby are
                         given, covering such items as reagents, steam, power, cool-
                         ing water, labor, and supervision. The possibilities of the
                         process' being applied to the recovery of sulfur dioxide from
                         low-grade industrial gases by the use other reagents having
                         m high absorptive capacity for the gaa are briefly noted.
                                                                The priucipul uovi-I  fea-
                                                              tures of tho Asjirco process
                                                              using  dimethylanilino  rea
                                                              ge,nt consist »f :

                                                                1, Incorporating the re-
                                                              generation unit for treat-
                                                              ment  of  recaptured  di-
                                                              lucthylunilme sulfnte as an
                                                              inteRrnI  part of the a-lworp-
                                                              tion-ilfKoqjtii'ii  cyolt;  !hi.s
                                                              sjivrs labor ;ind steam  :ui-
                                                              tion-dcsurptinii  cyeic  :mrriiiiioti.
                                                                3,  iimlallinj; just  above
                                                              the absorption  .sitflimi  «f
                                                              tower, two inibbk1-e:t[> tr;ivs
                                                              where (he sodium carbonate
                              _                       solution is eonvi'i'letl to so-
                                                              dium sit Hit R <>r bi-itilfile bv
                                                              tho rwidn.'il  sulfur dioxide
                               In tlio exit gases; this pormits regcneniHon of diiuotbylaiiiline in
                               thn closed ubsorption-desorption eyele, a]k)wing (lie eont'euirdti'd
                               siilfiif dloxidi) to (siitur tha wmipwssof fi'oo uf enrhuti iliii<,iti.'.
                                 4.  llecapturing  prautieally all  the  diinelhylaiiiliiH' v.ipor,
                               which has oseupwl from tho absorption  tower,  in a bubble-cap,
                               nine-trny exteiiHioa of the HIIIDO tower wliere tho vapor i,< si-nil'beit
                               with dilute Hulfuric acul flowing counlerKurrenl to u:i>- How.
                                 5.  Hecovering and  returning u  eimsidorable port km of  tin*
                               diiURthylaiiilino to tho tilMorlxtr without the neeawi) y »if !i,-:iling
                               it in tho main regi'iierat iun unit,
                                                         A comparison of dimotliylaiiilino and .xylidino, as u
                                                       sulfur dioxide, B!IOWS that oitoh has some  iulv:u>hi
                                                       other,  Dinietliylanilino is lined substantially dry
                                                       dinoin used in a mixture of one-half xylidiiu! and oiif^-
                                                         TSio ability of dimethylunillne mid xylidini* tn ab.-.o,
                                                       oxiJo from fluo gun is Khiiwn on Figure 1, eurvi',-t ,1 a
                                                       ttbsorptiim isotherms show that xylidine, curve H, n »
                                                       Borbant for sulfur dioxide in tho lower pwenttiyi'S by v
                                                       dimethylanilino, curve A, u a bettor nbsorhanl for

-------
  2254
                                 INDUSTRIAL AND  ENGINEERING  CHEMISTRY
                                                Vol.
  in tin- hvlior concentrations.  The two isotherms cross nt about
  U..V", fiutfur dioxide by volume.
   Tl\e Mobility «( s«lf«r dioxide from g»s mixtures in ditneUiyl-
  flnilii',0 follows  Henry's linv, but this law docs not apply when xy-
  lidine ix u»'d.   ID this case lew hen!, would be generated in the ab-
  sorber when treating the higher grades of sulfur dioxido with di-
  njctlivtaniline than  with xylidine.  Thin  would entail  ft less ef-
  ficient cooling system when using dtmpthylaniline.
                   100    (SO    200   2SO    SOU    55O
                 fUR BOXIDE CRAMS PER LITER AT ZO-Z3* C.
                                                          00
             1.   Absorption IsotHerrtiB of Sul£ur Dioxide
            tuUur cUomide and xylidiri* (1:1 *ylicHn»
[*miHn«; Curir»
imdi w*t«r)
   The vapor pressure of dimethylaniline at 20° C, 18 0.35 nun.,
 and tln> vapor presMire of xylidinc nt the same temperature is 0.20
 mm.  This indicates ;i slight  saving of sulfuric acid when re-
 covering xyhumc v;ij>or a.s compared with dimethybmilino vapor.
   The. Fohibi'iiiy cf dimethylaniline sulfato in water  is much
 (CrenU'r  t'i.'in the solubility of xylidino sulfate in water.  There-
 fore, the weak sulfiirie aoid solution from the scrubbers, when us-
 ir,ii dir.iethyl.inilitie, can carry a much greater lo.id of dimethyl-
 .tnilino to (he regenerator than when xylidinc is used.  To some
 extent this jjrcatcr  sohtliilily would offset the Advantage of  the
 lower vapor pressure of xylidiiie.
   During the absorption of sulfur ilioxklc with cither dimethyl-
 aniline or xylidiiic there is scviue oxidation of sulfur dioxide to sul-
 fur trioxUU: iifthoiiKh in the trcntment of gns  containing 3.5%
 sulfur dinxido or over,  the  conversion is cjuitc small, being  !ij>-
 proxtiuiitoly O.HO^J,.  in She. treattnfnt of gas under this grade,
 the j>ereent!tn<« of <>\id:ition imircjLies rapitily, pnrticulnrly with
 thr u*(' of xylidine in iv.-iter ."-'uspension.
   In  the diniRthyl.'uiilinc prowss all t,h«> water nliniinnted as steiim
 from the recenrrntiiifj ;ind stripping operation in condRris«i.   Af-
 t anhydrous dimnthylrinilino in the  gravity
 wpiir.-itor, all  UK- wa(<-r pli.'im> is returned  to  the regenerator.
 I'nder these eojiditi'iiis the su'fafe radical which forms is continu-
 ously  removed  from the iilisorptiou  cireuit thus eliminating  the
 pos>ih]e  formation r>f any Kc^litl reaetioEi products.
   With  the use of  the xylidiue-water wisponsion process, great
 care mart bft taken to  prevent the formation  of solid  reaction
 products, even when treating K!'S relatively high in sulfur dioxide.
 In  this case, if tiie sulfatc radical in  the water phnse is not kept
 within low limits by bleeding sufficient water to the regenerator,
 rapid mitoxidalion triA«-s plare to the extent that the xylidine sul-
 fate, having a low watilitit> ],v
 tin; advantage, of lower uteum consumption, and the prom^ r,,
 quit'eH fewer  skilled operator  and  I«'NH wipervisiou.   Also  tlr
 very low grart,
 would bo Jitt.le difference when using  the Awirwi wywtflin of OIKTI-
 tion.   In  the opinion of the ntithors the advantages of diiiK'tiiv).
 aniline nrc such that it enn be u.sed competitively with xylidine on
 sulfur dioxide gsts w low HH 2.0% by volume.
   Following 0 months'  operation of a  1-t^iii diinethylanilmc nt
 Horption unit on 0,0% milfur  diox«!e gan at Oarfiold, Utah, it »a,
 decided to build a 2.5-t
-------
  Kovember  1950
                                INDUSTRIAL AND  ENGINEERING  CHEMISTRY
                                                           2255
  time of the Norwegian installation, but Aauroo took no part hi the
  fcign of plant, und tho operation there did not follow the pre»-
   { process system us installed at Selby.  Iteccntly, changes have
  ten\ made at Kristiansand to tako advantago of some features of
  he Asarco process.
   The present plant at the Sclby lead smelter  went into opera-
  ion in September 10-17,  In order to take cure of the bulk of Fa-
  ilic Const ree|iiirenicnts mid allow a surplus of 100% sulfur dio.x-
   i1 i'.n» tor  emii'Iiing  HIM) pliibili/.ing  the  supply  to adjoining
   id (limit, thu design  ciilleil  lor  u  enp«ellj' u{  i!tl lonw  pur  ility,
   his wiis biiM'd on a supply of gas fi'nm Ihvight-Lloyd sintoring
   ;icliin«'fi averaging 5,0% sulfur dioxide by volume,   As regards
  limit capacity, atciiui I'niiNuniption,  dimutliylunilino loss,  and
  icilily of o|n-ration lln» unit IIHH (weeedi'd exiH'Rtiilions.
   l>l«iiitiuiw iluritig IIIH> indicate the following biisiudutai
  Iti'rovrry uf KOi from &.()','» Jinn, %
  UinH'thylamlini! I'uBmnm-d/tim SOi prodm-pd, 1b.
  SuMiium I'urhotm!*1 eniimimcil/toii SO? produced, Ih.
  Snlfurk ai'i'l t'«!ri'nimf1*&/tou HI*; pro^m'c*!, Ib.
  Su-am e<3n.«uiui:d./lim BOi i^rodtKvd, tim*
  POVKT", kw.-hr.
  Cooling wiitcr at (i5° FM giiJ./miii,
                                                         t)u,o
                                                          1.1
                                                         35.0
                                                         40 0
                                                          1,2
                                                        145
                                                        300
  11 Provided OH' SOt in pro
 R|>pr«ximHU'!y 100 kw.-lir.
                            SB n 100% ga^ puwer conauniption will be
  These datu do not include labor, power, and water used for the
 purification of gas prior to entering the sulfur dioxide plant proper,
  The labor required to oiwratc the plant consists of one foreman
 on day shift only, thrw wliift operators, uiul on« ipsnnrul utility
 limn on tiny f.tiifl.  Tlu> MLIIHI ITUW I'uii upcriLte a pltuit of mtvoral
 timcM ScWiy'M capucity.   In addition, Mii]M'rviNioii and HOtnu vlunuU
 cal control wurk urcrniuiiwl.
  It i« iliff'ieult ut tliis ti)ni: lo pivi' a fair I'Htiinutu of miiinteiiuiioo
 rusts.  Tlic* plant hu>) tii'cu going tlsrough a dewlopntciit stage in
 tlip scl(H'tinn of tlit! best corrosion resistant jiiBturiul,  Recently,
 lead has bei-i» substituted  for 3I('» Htiiinlcsa KUsel in the coiiBtruo-
 1iru.te gus purification wystem at Selby is nec-
WiHiiry lii!cauw> of tho high impurities in the gits stream.
  T
ine
can
rel
          ASARCO SULFUR DIOXIDE PROCESS
    ho proeusu fur the recovery of eulfur dioxido from flue gna by
    is of dimi'thylanilinu ubsorbant, UH duvelopisd by the Ameri-
    Hmeltirijj; and Itiifining Company, consists essoatially of two,
   ted clo«t;d <:iriiiiit ojHirationB, curriwl  out siinultiuioously,  in
    twfj main bubble-cap towers- nttmi'ly,  tho absorbing towor
    the htri)i[iiii|{ tower,   Tho first operation eotiNwtB of recov-
   of Kiilfur dioKidi; from lliu (ItlcgiiK by absorption in diimnhyl-
   im: iind its wib«e(|iiuiit stri|j|)iii« I'nitii Uici j>rijMTuti«>ii itoimislH f)f  tho  recovery of the
   iclliyliiiiilinc which CWUJM« into the gan sttrenm during tho ab-
   itiiui (tjii'j-jiti«»ii and from  Shut dksolvod in water dtiriiiK thn
   pptiij; ijpcnition.  Without tlio  recovery of dimethyhutiliiiB
   prMiilici' through metering
devices from the supply in the- ditiielliyhiniline Mir^e t;uik.  The
sulfur dinxido dissolves in  tin* dimelhylaniliiie, and as Ilie Hue H.'I.H
iMteunicH impuvt'fishril in sulfur diitUtle i( bi-eonie.-: enriched  with
dhucthylsnUuio vapor.  Tlie  diriH'thylutuhiic  in (Utuii^  tlown-
Wiinl from tray to tray becomes richer in ili-isnlvc.l sulfur dioxide
mid changes in color from light-yellow to a deep rul'v-rcd solution.
  Considerable heat w evolwd during tin' :ibsi>iptioti of sulfur di-
oxido by the dimt'thyhinUini1, iiml  inleivonlers  :md putupx aro

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2256
                               INDUSTRIAL  AND  ENGINEERING  CHIMISTBY
                                             Vol. 42,  No, 11
                              Figure 3.  Flow Diagram of Aaarco Ijiquid Sulfur Dioxide Plant
provided on the .'ibnorber to dissipate this heat of solution.   Tho
qunniity of sulfur dioxide which a given weight of ditnelhylaniline
tun 
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 November 1950
INDUSTRIAL AND  ENGINEERING  CHEMISTRY
2257
                 ,       • -  •                 -
              iiaij  •  -t  JfCiittifiaiP    -iiifft'*1"-'ij
   Figuro 4.   Irutitament Panel, Selby Liquid Sulfur
                                Plant
  Tin1 !lu>- gns LS impoverished in sulfur dioxide and enriches! in
 ilmicthylanilitie vapors while po-ssing through the ateorber unit,
 Thf due g:w leaves the absorber and is bubbled through two trays
 of dilute sodium carbonate solution in  tho 8oda scrubber.   Any
 FKi'hiul auUur dioxide in Uio flue gtus converts the sodium carbon-
 ate to siodium stiinte or bisulfite,  Tho carbon dioxide is liber-
 als! in (lie flue gas.  Any spray or droplets of diniethylaiiilme are
 irapix'il in this section and escape with the liquid effluent from
 tins unit.
  The fhir» gits substantially free of physical ditnethylaniline liq-
 uid but containing vapor of dimethylanitine is caused  to bubble
 through nine trays of bubble cups irrigated with a dilute sulfuric
 tirid solution.  The  acid and  the dimcthylaiiiliwe- base react to
 furiiidiiiu-lliylaiiiliiiCflulfute.
  The dilute sulfuric acid is fed onto the top truy of the third unit
 of ;!«> MisoyVmn UIVMT or  tin* nr.id scrubber at a rate  to almost
 t-'atiiriife tht" ncid with diinethylamlme on tho bottom tray of this
 ii.'iit .in.!  to maintain n concentration of dimethylaoiline in the
 ii i-1 sampled from tho top  (ray of less than ono twentieth satura-
 tion.  'J'lit flue gus which leaves tho tower at this point and flows
 into Uu.' atmosphere contains  a  fraction of 1%  of sulfur diosade
 and j>r;;t'lien1iy no dimethylmiiline,
  The eH'uent from the soda truyet and  the acid scrubber empties
 ia'o :i tdlWlJnc tank and is pumpL'd up  to asma!! gi'avity separa-
 tor, wlmri! ;i ;it, vnlv.; l,n :i
                                   pll cell and then to tho newer,   Tho sodium mil fate fomu-d in  (lit;
                                   regenerator iu thrown to wiujte.
                                      The. pll of the water Molution  in tin) regenerator i.s niainS.'iincd
                                   betwiicn 5 and 0 and is adjusted by the rule of How of sodium car-
                                   bonate solution to the soda .scrubber.  The ellluent water con-
                                   tains no dissolved dimctliySanilinc.
                                      There are only three passible Kourrofi of low <>f dinu'thyluniline
                                   from (he process cycle -  namely:

                                      1,  A,H dimel.hylnnilini! vapor cHeupin^ from  the absorption
                                   tower with th« iiupovcri.shed flue KHH
                                      2.  AH dimcthylaniline dissolved in the water effluent from  the
                                         As mechanical leaks in pump glands, valve packing glands,
                                   and pipe threads

                                     The firet two sources of loss are recoverable and may !«; (fon-
                                   trollod by correct operation of the process, and tho third source of
                                   loas is preventable.
                                     The operation of the Asarco  process  is smooth and flexible.
                                   The plant may be shut down and started up without dilFieulty.
                                   There arc  only six control  valves on the process;  these control
                                   solution flow rates, and the levels of liquid iu ihc various units are
                                   automatically maintained by float valves.   There is no juggling
                                   of flow rates to maintain normal liquid levels in the units irt the,
                                   two bubble-cup towers.
                                     The operation of tho plant takes place principally from one
                                      T'
                                      f
                                                                  Uiij,
                                      I     ••-*	,,
                                                                                              1
                                                   til
                                                                           JDioxid*J?!«\.t

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 2258
                            INDUSTRIAL AMD  ENGINEERING CHEMISTRY
                                                                                                 Vol. 42, No.
fUw and from one instrument pmifl.  This is nhown in Figure -f,
Tl»> utstrumrnls consist of ft temperature recorder, » vncuum wwl
pro-ware Rftff for blower nnil n.1 unii^r, integrating and recording
line i;;i.s fltnnnrtrr nml steam flnwmotw, rolmnotor for  liquid flow
control, and rnuole iiulirnlitiR  (.,'tnk  level RBKW,  Tho IliHtrit-
iiionis !ils 130
                                                              New York, MrfirawJIiU Hook (Jo., 1riv(it,p invmtiKntion, American SmHtin;; nni|
                                                              IteliniiiK (^o., Tacnmii,  Waeli. (HI29).
                                                         (7) Sulphur 1'ntent.n Jf Su|.
                                                              phtlr from Smelter (Simon" (1000),
                                                         (») Tlimnw, M. !>., Ivio, J. <)., »n,\ Kilt, T. f!., INO, KVK. fHn,
                                                              AMAT,, Kn., 18, .18,1 (Hun).
                                                         (!)) Woicimntin, If., and llrsraitior,  d,, Mi-taHgr*, /VnWi'c /irf  |j
                                                              7-13 (IflOT);  Ind, Krtg. V.hrni., Ntw* Ed., 14,  1r»!j {llKJfl).'
                                                         RBOIHVIB March 27, tflfifl.
    Recovery  of   Sulfur  Compounds

  from  Atmospheric   Contaminants
                                             MORRIS KATZ
                            D*f*nc* ReiearehOh*mlcal Laboratories, Ottawa, Canada
                                                R. J. COLE
                                 Ontario Rafiaareh Faundallon, Toronto,
 I ho ciniraion of sulfur compounds, rocognlzod &e  major
atmospheric contnintnants, must be reduced na a matter
oi economics and in the interest of public welfare.  Great
strides have been made in the control oi smelt«r smoko
damage by scientific investigation of sulfur dioxide injury
to plant life,  and the application of remedial measures,
whicH include use of high stacks and high temperature*
for the discharge of waste gasoa, continuous  automatic
measurement of ground concentrations and application
of meteorological control by accurate forecasting of critical
weather  conditions, and  installation of recovery plants
for conversion of excess sulfur dioxide to Ucruid  sulfur
dioxide,  sulfuric  acid,  fertilizers,  or elemental sulfur.
The annual losses of sulfur from products discharged to
the atmosphere from zinc plants,  lead, copper,  and nickel
smelters, crude oil refineries, and from coal combustion,
are compared with world native suHur production  and
fay-product  sulfur recovery.   The extent to which, aulfur
emission must ba reduced, to avoid injury to  plant  life,
is discussed in terms of the permissible levels o£ ground
concentration. Methods  for recovery  of sulfur  com-
pounds from sulfur dioxide and hydrogen eulfide in stack
gas include concentration of sulfur dioxide and its con-
version to sulfuric acid, recovery a« elemental aulfur,  and
flue  gas  disposal of the effluent  and noneffluent  types.
New developments  of outstanding  importance for puri-
fication  and  recovery  of sulfur dioxide  are  embodied
in the Trail ammonia process, the dimethylaniline process
•tSelfcy, ahS Rash smelting at Copper~C!ifi in conjunction
with liquid sulfur dioxide recovery. An aroused public
consciousness  of  the need  of controlling  atmospheric ,
pollution has stimulated investigation in many contaml-
                                                        nated areas.  SuHur contaminants may ba profitably re-
                                                        covered In many industrial operations and thus clean up
                                                        the air and add to native aulfur reservos, which are rapidly
                                                        being depleted in tho United States.  More research u
                                                        needed  in industries confronted with difficult recovery
                                                        problems—for  example,  nickel  Bmeltern.  Cooperation
                                                        between major native sulfur producers  and companies
                                                        •with a large sulfur problem on their hands is desirable.
                                                            SULFUR compounds have been recognized as major ;dii«.
                                                            plierlc contaminants for mnny years in the metal sincltini!
                                                        Bnd oil refining industries, and in all operations involving tlw
                                                        consumption of large quantities of sulfur-containing fuels such n."
                                                        coal.  Enormous damage has been caused by tho excessive emis-
                                                        sion and wastage of such products to agricultural and forest ttrcn.?,
                                                        and to materials such as nietnls, atone, cement, paint, pupcr,
                                                        leather, and textiles.  The nnnunl Infwes from nir pollution cannot
                                                        be assessed accurately but,  nevertheless,  nnmunt to  man)
                                                        millions of dollars.  If one considers (hat, a suhstnnt.irJ portion of
                                                        tho sulfur dioxide or hydrogen Biilfide  lost to the atmosphere
                                                        may be economically recovered, the, real magnitude o( such taws
                                                        and the importance of tide problem l»ceoine  apparent.
                                                          Within the. past 20 years a great scientific effort has Ixwn mad*
                                                        in the United  Stales, Canada, and elsewhere to determine tlw
                                                        causes of air pollution and to develop tcelimcal methods of con-
                                                        trol.  Tho effect of sulfur dioxide on plant life and metabolism,
                                                        IilKitosyritheaia and respiration, and the factors affecting suscep-
                                                        tibility have been evaluated with scientific accuracy.  Consider-
                                                       . able insight has been gained into tho role of nucromoteorology
                                                        and the influence of topography on smog conditions aecom-

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                                TECHNICAL REPORT DATA
                          (Please read Inunctions on the reverse before completing)
1. REPORT NO.
 EPA-600/2-76-036k
4. TITLE AND SUBTITLE
 Design and Operating Parameters for Emission •
 Control Studies; ASARCO, Tacoma, Copper Smelter
            5. REPORT DATE
             February 1976
            6, PERFORMING ORGANIZATION CODE
J, AUTHOR(S)

I. J. Weisenberg and J. C.  Serne
                                                      B. PERFORMING ORGANIZATION REPORT NO.
                                                      3. RECIPIENT'S ACCESSION-NO.
9. PERFORMING ORG '\NIZATION NAME AND ADDRESS
 Pacific Environmental Services, Inc.
 1930 14th Street
 Santa Monica, CA  90404
            10. PBOORAM ELEMENT NO.

            1AB013; ROAP 21ADC-061
            11. CONTRACT/GRANT NO.

            68-02-1405, TaskS
12. SPONSORING AGENCY NAME AND ADDRESS
 EPA, Office of Research and Development
 Industrial Environmental Research Laboratory
 Research Triangle Park, NC 27711
            13, TYPE OF REPORT AND PERIOD COVERED
            Task Final; 4-10/75	
            14. SPONSORINQ AGENCY CODE
            EPA-GRD
15. SUPPLEMENTARY NOTES
 EPA Task Officer for this report is R.Rovang, 919/549-8411, Ext 2557.
is. ABSTRACT
              repOr^ gives background design data for a specific copper smelter,
 The data is sufficiently detailed to allow air pollution control system engineering
 studies to be conducted.  These studies will be concerned primarily with lean SO2
 streams that currently are not being captured.   Physical layout of the smelter and
 the surrounding area is presented, along with existing control equipment.  Ductwork
 that would be considered for future system tie-in is defined. Emissions from
 operating equipment, gas flow rates,  temperatures, sulfur balance, and a process
 flow sheet are included.  Utilities , stack dimensions , footing requirements , and
 solid waste handling are defined.  Available area for  new control equipment,  gas
 characteristic variation,  and potential new control equipment installation
 problems  are discussed.
17.
                             KEV WORDS AND DOCUMENT ANALYSIS
                DESCRIPTORS
b.lDENTIFIERS/OPEN ENDED TERMS  C, CCSATI Field/Group
Air Pollution
Copper
Smelters
Design
Sulfur Dioxide
Utilities
Air Pollution Control
Stationary Sources
Emission Control
Operating Data
Solid Waste Handling
Wastes
 13 B
07B
 11F
18. DISTRIBUTION STATEMENT

 Unlimited
19. SECURITY CLASS (ThisReport)
Unclassified
[21. Up. OJ= PAGES
                                       \L
2O. SECURITY CLASS (Thispage)
Unclassified
EPA Form 2220-1 {9-73}

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