ENVIRONMENTAL PROT*mON AGENCY
            OFFICE OF ENFORCEMENT
                 EPA-330/2-77-010
               Evaluation of
  Zinc Fuming Furnace Fugitive Emissions
         Bunker Hill Lead Smelter
               Kellogg,  Idaho
NATIONAL ENFORCEMENT INVESTIGATIONS CENTER
              DENVER.COLORADO
                  APRIL  1977

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           Environmental  Protection Agency
                Office of Enforcement
                  EPA-330/2-77-010
EVALUATION OF ZINC FUMING FURNACE FUGITIVE EMISSIONS

              BUNKER HILL LEAD SMELTER

                   KELLOGG, IDAHO
                     April 1977
     National Enforcement Investigations Center
                  Denver, Colorado

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                            CONTENTS


   I    INTRODUCTION  	    1

  II    SUMMARY  AND CONCLUSIONS   	    3
       Compliance Status   	    3
       Company  Approach  	    3
       Planned  Modifications   	    4
       Maintenance and Operation  	    4
       Charging Emissions  Controls   	    4
       Process  Modifications   	    5
       Cost Estimates  	    5

 III    RECOMMENDATIONS   	    6

  IV    PROCESS  DESCRIPTION  	    7

       Lead Smelter	    7
       Zinc Fuming Plant  	    9

   V    APPLICABLE  REGULATIONS  	    27
       Regulation  F  -  Control  of Fugitive Dust	    27
       Regulation  H  -  Control  of Particulate
         Emissions From  Industrial  Processes   	    28

  VI    PARTICULATE COLLECTION  AND CONTROL 	    30
       Operation and Maintenance  	    30
       Process  Modifications   	    32
       Charging Emissions  Collection  	    34
       Charging Emissions  Control 	    39

 VII    COST ANALYSIS	    42

VIII    RELATED  INDUSTRY  EXPERIENCE  	    45
       ASARCO - Montana	    45
       ASARCO - Texas	    54


       REFERENCES	    61

       BIBLIOGRAPHY  	    62

       APPENDICES

       A   113  Notice  of Violation
       B   Idaho Air Regulations F and H
       C   Calculations

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                            TABLES

 1  Typical Operating Data for the Zinc Fuming Furnace .  . 12
 2  Design Parameters and Specifications for Slag
      Granulating Pit Scrubber 	 17
 3  Design and Actual Parameters for the Zinc
      Oxide Baghouse	21
 4  Estimated Mass Rates for the Zinc Fuming Plant .... 26
 5  Allowable Rate of Emission Based on Process
      Weight Rate	29
 6  Alternatives for Providing Appropriate Ventilation
      of the Zinc Fuming Furnace Charging Area	37
 7  Alternatives for Collecting and Controlling
      Particulate from Zinc Fuming Furnace Charging
      Emissions	40
 8  Summary of Costs for Alternatives to Reduce Zinc
      Fuming Furnace Fugitive Emissions  	 43
 9  Operating and Design Information - ASARCO,
      Montana Zinc Fuming Plant  	 49
10  Operating and Design Information - ASARCO,
      Texas Zinc Fuming Plant	58
                            FIGURES

 1  Simplified Process Flow Sheet  	  8
 2  Process Flow Diagram 	 10
 3  Physical Arrangement of Zinc Fuming Furnace and
      Waste Heat Boiler (1957)	13
 4  Fan Characteristic Curves for Zinc Fuming Plant
      Stack Fan	33
 5  Elevation Drawing Showing Location of Existing
      Charge Area Hood for the Zinc Fuming Plant 	 34
 6  Sketch of Hooding Arrangement for Zinc Fuming
      Furnace Charge Area (Alternative A)  	 33
 7  ASARCO, East Helena, Montana -
      Lead Smelter Plant Flow Sheet	46
 8  ASARCO, East Helena, Montana -
      Zinc Fuming Plant Flow Sheet   	48
 9  Process Flow Diagram for Lead and Zinc Dept.,
      ASARCO-E1 Paso Smeltering Works  	 54
10  Process Flow Diagram for Zinc Fuming Plant,
      Lead Dept., ASARCO-E1  Paso Smeltering Works  .... 57

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                           I.   INTRODUCTION
     The Bunker Hill Company, a subsidiary of Gulf Resources and Chemical
Corporation, operates a mine flotation mill, a lead smelter and a zinc
smelter at Kellogg, Idaho.  Lead and zinc concentrates produced from the
mill and from other foreign and United States mills are charged to the
custom lead and zinc smelters for processing.  Besides refined lead and
zinc, the Company produces black and clear sulfuric acid,  high-purity
silver, antimonial (hard) lead, zinc oxide, dore metal (silver-gold
alloy), copper matte and cadmium sponge at this location.

     On or about September 22, 1976, the Bunker Hill  Company was issued
a Section 113 (Clean Air Act) Notice of Violation [see Appendix A]
addressing several areas of the lead smelter, including the blast furnace,
sintering process area, zinc fuming plant, silver retort and lead refinery.
Since then, the Company has proceeded with corrective action on all
areas with the exception of the zinc fuming plant charge area for which
the Company was to provide adequate exhaust capability to an appropriate
control device.  The Company has refused to comply with control require-
ments for the zinc fuming furnace charging emissions, stating that these
emissions were too insignificant to warrant the cost involved, estimated
by the Company to be $300,000.:  As a result, Environmental Protection
Agency (EPA) Region X asked the National Enforcement Investigations
Center (NEIC) to analyze the availability and feasibility of technology
for the Bunker Hill zinc fuming plant to comply with the fugitive emis-
sion regulation (Idaho Air Pollution Regulation F) and the process
weight regulation (Idaho Air Pollution Regulation H).  Region X also
asked the NEIC to determine the capital and operating costs associated
with any recommendations.

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     In August 1976, the NEIC inspected the Bunker Hill  lead smelter  and
requested further information from the Bunker Hill Company.   This  infor-
mation was provided by the Company during October 1976 with  subsequent
data requested and provided in January and February 1977.  An additional
visit to the smelter was made during February 1977.  To  obtain further
background information, the NEIC conducted inspections of  the zinc
fuming furnace operations at ASARCO lead smelters in East  Helena,  Montana
and El Paso, Texas in 1976-77.

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                     II.  SUMMARY AND CONCLUSIONS
     A technical evaluation and cost analysis of the zinc fuming plant
at the Bunker Hill lead smelter was conducted.  The evaluation reviewed
means by which the emissions from the plant could be brought into com-
pliance with Idaho Air Regulation H (process weight) and Regulation F
(fugitive dust).  The results of the review are as follows.
COMPLIANCE STATUS

     The zinc fuming plant does not comply with Idaho particulate
Regulation F.  Compliance with Regulation F is interpreted to require
installation of a more effective charge area hood and subsequent gas
treatment in a particulate removal device.  The plant does comply with
Regulation H, if consideration is given only to those particulate sources
for which Method 5  determinations were made.
COMPANY APPROACH

     Based on information provided by the Bunker Hill Company personnel,
it is believed that the Company was not sufficiently thorough in its
evaluation of zinc fuming furnace charging emission controls.  Their
limited review of the problem did not adequately evaluate possible
process and control system alternatives.  Furthermore, the Company's
statement that charging emission controls are not practical  contradicts
practices at other lead smelters.  Of the two other zinc fuming opera-
tions known to be in existence in the United States, one is  currently
using charging emission controls while the other intends to  have con-
trols by late 1977.
   Code of Federal Regulations,  Title 40,  Part 60.

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PLANNED MODIFICATIONS

     Currently, the Company is expanding the main lead smelter baghouse
capacity, increasing the zinc fuming plant stack fan capability and
rebuilding the zinc oxide baghouse.  The latter two modifications will
cause a small reduction in the existing fuming plant fugitive emissions.
However, there has been no apparent attempt to expand any of these
modifications into a comprehensive plan which would significantly reduce
fugitive emissions.


MAINTENANCE AND OPERATION

     There are some modifications which can be made to existing main-
tenance and operating practices which could reduce the fugitive emis-
sions.  The most readily applicable of these includes more frequent
inspections of and adjustments to, the waste heat boiler lance doors.
It is significant, however, that during EPA inspections, parts of both
the waste heat boilers and the zinc fuming furnace were observed to be
under positive pressure.  Since these units were designed for negative
pressure, no amount of maintenance would completely eliminate door
leakage.  Maintenance and operating modifications developed during this
review could be employed with little or no associated cost.


CHARGING EMISSIONS CONTROLS

     Control  of charging emissions at the zinc fuming plant can be
accomplished by installing effective fume collection hoods which would
vent to an appropriate particulate removal  device.  Appropriate par-  .
ticulate removal  could be provided by expanding the present zinc oxide
baghouse or by installing a new baghouse.  The installed cost of con-
trols including the expansion of the existing zinc oxide baghouse is
estimated by NEIC at $320,000, while the cost of controls utilizing a
new baghouse is estimated at $370,000.   Annual  operating costs are
estimated as  $75,000 and $83,000, respectively.

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      It may also be possible that the modified main lead smelter bag-
 house could be used for treating zinc fuming charging emissions.  However,
 the Company has expressed concern that this  baghouse when modified will
 marginally handle planned gas streams.  Consequently, the use  of the
 main baghouse for the zinc fuming furnace  charge  emissions must be
 reviewed after the modified main baghouse  is operating.   The  installed
 cost using the main baghouse for charging  emissions is estimated by NEIC
 to be $57,000, assuming very few additional  changes to the baghouse are
 necessary.  The added annual  operating cost  would  be $14,000.


 PROCESS MODIFICATIONS

      Various process  modifications,  in addition to or in  conjunction
 with charging emission  controls,  can  be made to increase  available draft
 in the zinc  fuming furnace.   These include installing an  additional
 stack fan  and expanding the  existing  baghouse.  The  modifications  alone
 would not  assure  compliance with  fugitive emission  regulation, but would
 reduce charging emissions  and  thereby reduce  the extent of control and
 above-estimated costs for  charging emission  controls.  The estimated
 installed  costs developed  by NEIC for these modifications are:   new
 stack fan  —$64,000,  and an expanded  zinc oxide baghouse  — $195,000.
 Annual  operating  costs  are expected to  be:  new stack fan — $22,000,
 and  an  expanded zinc oxide baghouse ~  $52,000.


 COST  ESTIMATES

     All cost estimates developed in  this study should be considered as
 preliminary  (+30%) estimates.  Installed costs include engineering,
 installation and equipment costs, but do not include costs associated
with production time lost during installation.  Annual operating costs
 include direct costs, such as maintenance,  replacement parts,  etc., as
well as indirect costs incurred in depreciation, taxes and insurance.

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                         III.   RECOMMENDATIONS
     It is recommended that appropriate enforcement action be  initiated
against the Bunker Hill  Company for violation of the existing  113  Notice
of Violation for zinc fuming furnace charging area controls.   It is
further recommended that any subsequent judicial  or administrative
agreement include the following considerations:

     1.   A date for rebuilding the zinc oxide baghouse and increasing
          the zinc fuming plant stack fan capability.

     2.   A schedule for the Company to design and install a  particulate
          control system to control zinc fuming furnace charging emis-
          sions and to come into compliance with Idaho Regulation  F.

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                       IV.  PROCESS DESCRIPTION
LEAD SMELTER*

     The primary function of the Bunker Hill Company lead smelter is to
convert lead concentrate into a high-purity lead product.  A simplified
flow diagram for the smelter is shown in Figure 1.

     Once at the lead smelter, the concentrates are sampled, blended
with other feed materials and pelletized in a dryer.  This pelletized
mixture is conveyed to an updraft sinter machine where it is laid on a
traveling grate, ignited and burned.  A large portion of the lead sulfide
(PbS) in the feed is oxidized to lead oxide (PbO) and sulfur dioxide
(SOg).  The sinter operation produces a porous sinter material  and a
byproduct gas containing the S02> a portion of which is captured and
converted to sulfuric acid in a single-contact, single-adsorption acid
plant.  Remaining S02, which is emitted from the tail end of the sinter
machine, is exhausted directly to the main stack.  Fines from the sinter
process are recycled through the sinter return circuit.

     The sinter is mixed with coke and charged to the blast furnace
where it is burned with oxygen-enriched air.  As the coke burns, it
furnishes the heat necessary to reduce the sinter to two molten materials:
a lead bullion, and slag.  The slag is further processed in a zinc
fuming furnace before being stockpiled.  The flue gases from the zinc
fuming furnace contain zinc oxide, a part of which settles out  in the
flue system.   The remainder is removed in the baghouse.
   Information in this section is  derived from references  2,3.

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Figure 1.  Simplified process flow sheet for the Bunker Hill Lead Smelter
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     The lead bullion from the blast furnace is next purified through a
series of refining steps which include dressing in kettles, softening in
a furnace, and degolding, desilvering and dezincing in various other
kettles.  Copper, antimony, arsenic, silver and gold are removed during
these steps and treated further to provide marketable forms.  With the
proper amounts of impurities removed, the lead is cast into a final
product.


ZINC FUMING PLANT

System Description*

     The purpose of the zinc fuming plant is to recover zinc and lead
oxide from the slag generated in the lead smelter blast furnace operation.
The major components of the plant are the zinc fuming furnace, the raw
material charging systems, the slag granulating pit and scrubber, the
waste heat recovery and gas cooling systems, and the fume collection
system.  A flow diagram for the plant is shown in Figure 2.

     The Bunker Hill zinc fuming plant began operating in 1943.  It was
modified in 1956 to increase the furnace capacity and again in 1975 to
install a granulating scrubber.  Presently, the plant can process about
550 to 590 m. tons (600 to 650 tons)/day of blast furnace slag, producing
around 70 m. tons (75 tons)/day of zinc oxide fume.  The zinc fuming
plant is operated approximately 80% to 85% of the time the blast furnace
is on-line.

Furnace

     In practice, the zinc fuming furnace is a batch operation consisting
*  Information in this section is derived from references 4j 5, 63 ?t 8.

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                                                                     10
AIR
  TURBO

 BLOWERS
COAL
AIR
   *
                     SLAG  FUMING  PLANT
                            B F SLAG
   COAL
 PULVERIZER
            TERTIARY
              AIR
              FAN
GAS OR OIL
 STACK
  FAN
                          SLAG FUMING
                            FURNACE
                  WATER WALL
                   BOILER
                   SECTION
                COMBUSTION
                   SECTION
                WASTE HEAT
                   BOILER
                   SECTION
                          ECONOMIZER
                           SECTION
                                        ASH
                          ZnO FUME
                  ZnO COOLING
                     TOWER
                          ZnO FUME
                           NORBLO ZnO
                            BAGHOUSE
                                             I
                    RR  CAR  |
SCRUBBER

SLAG

                                                  GRANULATION
                                                      PIT
                               SURGE BIN
                            LEADED ZnO
                            TO MARKET       TO
                                           KILN
                                        ASH  f       |  RR CAR
                                           » '     »
                                              TO OPP
                                                        RR CAR
                                                TO
                                               OPP
                                              OR MARKET
  Figure 2.     Process Flow Diagram  for  Zinc  Fuming Plant,
                     Bunker Hill  Lead Smelter

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                                                                       11
 of  charging/heating, fuming, and tapping cycles.  In the charging/
 heating cycle, 4.5 m. ton (5.0 ton) capacity pots of blast furnace slag
 are charged to the furnace through a charge chute, while a pulverized
 coal and air mixture is  injected through tuyeres beneath the surface of
 the molten slag bath.  As combustion occurs, any solid slag present in
 the bath is melted as the operating temperature of the bath is maintained
 at  about 1,000 to 1,100°C (1,800 to 2,000°F).  After charging is completed,
 the furnace goes into a  fuming phase, during which time the amount of
 air entering the furnace bottom is about 60% to 75% of the theoretical
 air required for complete combustion.  Under these conditions, carbon
 monoxide is formed and reduces to metal the lead and zinc oxides present
 in  the slag.  The metals are vaporized, and tertiary air is then blown
 into the upper part of the furnace to reoxidize the metal vapor.  The
 coal added during the fuming cycle serves two conflicting purposes:  1)
 it  provides sufficient carbon monoxide during combustion to reduce the
 majority (90%) of the zinc oxide to zinc vapor, and 2) it releases
 enough heat to support the endothermic reduction reactions and maintain
 the temperature of the bath within the proper operating limits.   Typical
 data for the zinc fuming furnace operation are shown in Table 1.

     Physically, the fuming furnace is somewhat similar to a reverberatory
 furnace made up of steel water jackets [Figure 3].   The furnace  hearth
 is 4.5 m. long x 2.4 m.  wide x 6.8 m.  high (1j x 8 x 22 ft).  The entire
 furnace is water-jacketed with water space tapering from 32 cm (12.5 in)
 at the bottom to 13 cm (5 in) at top.   The charging door is 2.5  m (8 ft)
 in diameter, pneumatically operated, and also is water cooled.   The door
 is 4 m (13 ft)  above the bottom of the furnace.   The slag from the
 furnace is tapped through two water-cooled tapholes near the bottom of
the furnace.   Circulation of cooling water through  the water jackets is
accomplished by a thermo syphon action.

     The Company does not attempt to control  either furnace draft or
furnace temperature directly.   These variables  are  said to  be  kept

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                                                                1?.
                           Table 1

     TYPICAL OPERATING DATA FOP THE ZINC FUMING FURNACE
                  BUNKER HILL LEAD SMELTER7>B
Average cycle times                          (minutes)
     Charging/heating                           20
     Fuming                                     90
     Tapping                                    10

Charges/day                                     12

Material flowrates                      (m.tons/hr) (tons/hr)
     Blast furnace slag                   550-590    600-650
     Coal                                   100        110
     Fume collected                          70         75

Zinc/lead recovery                           (% by weight)
     Average lead in input slag                 1.9
     Average lead in output slag                 0
     Average zinc in input slag                  14
     Average zinc in output slag                1.4

Fuming furnace design pressure          -0.68 cm (-0.25 in)  W

t  WG = Water Gauge.

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Figure  3.    Physical  Arrangement of Zinc Fuming Furnace and Waste  Heat Boiler  (1957)
                              Bunker Hill  Lead  Smelter

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                                                                       14
within proper ranges by the controls used to maintain waste heat boiler
operation.  At present, indicators for furnace draft and temperature are
inoperable.  Company personnel  indicated that this is due to problems
caused by high temperature operation and slag formation on instrument
sensors.
Charging

     Operation of the zinc fuming furnace requires the input of air,
pulverized coal and blast furnace slag.  Combustion air and pulverized
coal are injected into the slag bath through 28 tuyeres, 14 on each side
of the furnace about 14 cm (5-1/2 in) above the furnace bottom.  Primary
and secondary air is provided by two Ingersoll-Rand* four-stage blowers
with a rated capacity of 195 m3/min (6,900 cfm) at 0.6 kg/cm2 (8 psig)
pressure.  The blowers are driven by Terry* steam turbines.  The tertiary
air required for reducing lead and zinc vapors is provided through two
headers at the top of the zinc fuming furnace.  Identical Buffalo Forge*
fans, 58 m3/min (2,040 cfm) at 6.4 cm Water Gauge (WG) (2-1/2 in WG)
supply the air requirements, for each of the headers.
     The amount of coal added is chiefly determined by the blast furnace
slag characteristics and the amount of steam to be generated in the
waste heat boiler.  The approximate coal requirement is roughly set by
adjusting the Bailey* Type V6 volumetric coal meters, located at the
inlet to the pulverizer feeders.  This control is typically not adjusted
to any extent from day-to-day operations.  Final control of coal addition
is accomplished by regulating the damper controlling the primary air
flow into the furnace.  During the charging/heating and fuming cycles
*  Brand name

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                                                                       15
the coal addition is preset at a fairly constant rate, depending on the
number of pots and the zinc content of the blast furnace slag.   The coal
feed rate for a given cycle is usually increased during lancing operations
and decreased during tapping.   Coal usage rates are estimated from the
Bailey volumetric meters by using an assumed coal density.

     The total flowrate of primary and secondary air is provided at a
relatively constant rate.  When primary air is reduced, more air will be
shunted through the secondary headers.  The flowrate through the latter
is not controlled.  As a result of this and the fact that the tertiary
flowrate is also held fairly constant, the air flowrate to the furnace
does not vary appreciably throughout the furnace cycle.  Primary air
flow, primary air pressure and secondary air flowrates are indicated by
instrumentation in the control room.

     The molten slag charged to the zinc fuming furnace is tapped from
the lead blast furnace into 4.5 m. ton (5 ton) capacity pots.  The pots
are lifted by an 18 m. ton (20 ton) capacity crane from the blast
furnace area to an area adjacent to the zinc fuming furnace.  The pots
are stockpiled until the charging cycle commences.  Then, each pot is
separately hoisted by a 9 m. ton (10 ton) crane to the charging area
platform located next to the furnace charge spout.  An operator manually
breaks up any slag skull which had formed on top of the pot as the slag
has cooled.  The charge door is opened and the pot is tipped into a
charge chute.  At the end of the period in which each pot is being
emptied, two high-pressure air/water nozzles are activated to help
remove slag from the sloping charge chute walls.  Operators also manually
clear material that hangs up in the chute.  The charge door is closed
and the emptied pot is lowered to ground level.

     The slag skull or shell remaining in the charging pot after normal
charging described above is handled in one of two ways:  1) it is
returned to the blast furnace for melting, or 2) it is emptied with the

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                                                                       16
other pot contents into the zinc fuming furnace.   The latter procedure
requires that enough heat be available to melt the skull  as well  as
permit the waste heat boiler to operate at proper steam production
rates.  If the remaining slag skull  is emptied into the furnace,  it is
necessary to bump the pot repeatedly against a bumper located just above
the charge door in order to break the slag skull  loose.

     A typical charge consists of 6 to 9 pots.  The operator records the
total amount of blast furnace slag emptied into the zinc fuming furnace
in the operator's log.
Slag Granulation

     At the conclusion of the zinc furnace fuming cycle, the spent slag
is tapped during a 10-minute period in which the hot slag is allowed to
flow out of the furnace through the tapping chute and is granulated by
water jets.  Approximately 450,000 1 (119,000 gal)/day of smelter
recycle and main reservoir water are used to granulate, cool and transfer
the slag from the granulating pit.  The slurry collected in the enclosed
granulating pit is pumped to the slag pile.

     The particulates which are generated during slag granulation are
captured within the enclosed space above the granulating pit.  They are
ventilated from the granulation pit through a Krebs Elbaire* scrubber
and discharged from a wet fan into a stub stack.  The design specifications
for the Krebs scrubber are presented in Table 2.

     The Company monitors the granulation operation from instrumentation
provided to indicate the granulating pit water level and granulating
water flowrate.  The operation of the scrubber is not monitored by
instrumentation.
   Brand name

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                                                                      17
                                Table 2
DESIGN PARAMETERS AND SPECIFICATIONS FOR SLAG GRANULATING PIT SCRUBBER
                       BUNKER HILL LEAD SMELTER
          Volume, inlet
          Temperature
          Pressure, inlet
          Density
    GAS
                o
     670 act.  m /min (24,000 acfm)
     88°C(191°F)saturated
     -2.5 cm WG (-1  in WG)
     0.7 kg/m3 (0.43 lb/ft3)
          Inlet loading
          Specific gravity
          Particulate size
PARTICULATE
     1.6 g/m3 (0.7 gr/acf)
     Not available
     Not available
          Manufacturer
          Model
          Date Installed
          Water Rate
          Pressure Drop
 SCRUBBER
    Krebs Elbaire
    PxH             8.6.2
          1975
    910 1 min (240 gal)/min
    7.5 cm WG (3 in WG)
          Fractional  efficiency   97.1%  by weight

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                                                                       18
Gas Cooling

     The fume-laden gas discharged from the zinc fuming furnace is at a
temperature of approximately 1,100°C (2,000°F).  To recover heat from
this gas and to cool the gas to within a proper temperature range for
acceptable baghouse operation, the gas is drawn through a cooling
system.  This system consists of a waste heat boiler, and a zinc oxide
cooling tower.  The waste heat boiler contains a water wall section, a
combustion section, the waste heat boiler proper, and an economizer.

     The gas from the zinc fuming furnace first passes into the waste
heat boiler.  It is designed to generate about 26,000 to 30,000 kg
(58,000 to 66,000 lb)/hr of steam at 17 atm (250 psig) pressure during
normal operating conditions.  The waste heat boiler proper and the
economizer consist of a series of tubes.  Water is fed to the economizer
tubes from two lower drums.  It rises through the economizer tubes to an
upper drum which feeds the waste heat boiler section.  This water then
is circulated through the lower boiler drums, and the boiler tube into
the upper steam boiler drum.  The combustion chamber has two oil- or
gas-fired burners which are used when the available steam production
from the zinc fuming furnace offgas falls below 23,000 kg (50,000 lb)/hr
of steam.  In addition, a separate auxiliary steam boiler is used if
both the furnace offgas and combustion system are unable to maintain
minimum steam requirements.  Instrumentation is provided to record steam
flow, steam pressure, waste gas temperature, waste gas pressure and
various other operating status indicators.

     The gases leaving the economizer section of the waste heat boiler
pass through a long balloon flue before entering a zinc oxide cooling
tower.  The cooling tower consists of a steel  box, 7.6 m.  wide by 20 m.
long by 5.6 m. deep (25 x 66 x 18 ft) divided into six compartments by
cross baffles.  Between each compartment, there are four large U-shaped
cooling pipes, 1  m.  diameter, extending from the top of one compartment

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                                                                       19
to the top of the next compartment.   The inlets of the pipes are fitted
with butterfly dampers to adjust or shut off the gas flow.   There are no
automatic controls for the cooling tower operation.   Operator judgment
dictates when to bypass one or more of the cooling pipe sections.  If
tower exit temperatures appear to be excessive, the operator simply raps
the cooling pipes with a sledge hammer to remove particulate deposits.

     The gas leaves the cooling towers through a second balloon flue and
into the zinc oxide baghouse.
Fume Collection

     The zinc oxide and lead oxide fumes are collected from the furnace
offgas in the economizer hoppers, ductwork, zinc oxide cooling tower,
and the zinc oxide baghouse.  The collected material (fume) in the
baghouse is usually transferred directly from the baghouse hoppers to
railroad cars or to the zinc smelter.  The material collected from the
other sources is conveyed by screw conveyor to railroad cars or to a
surge bin from which the dust may be further processed in a gas-fired
kiln.

     The zinc oxide baghouse consists of five Northern Blower Company
(NorBlo*) dust arresters, each with a dust-settling chamber and a bag
compartment.  Ambient air is introduced to the flue gas just prior to
the baghouse through preset louvers located near the inlet to the first
dust arrester.  Each bag compartment contains ten sections with 78 bags
per section.  Each Dacron* bag is 15 cm diameter by 2.5 m. long (6 in x
2.7 yd).  Each section is automatically isolated from the baghouse
*  Brand name

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                                                                       20
outlet flue and provided with reverse air when the compressed air shaker
for that section is activated.  The ten bag sections may be shaken on a
cycle of 4-1/2, 11 or 24 minutes with the length of shake per section
being adjustable.

     The design parameters and specifications for the zinc oxide baghouse
are shown in Table 3.

     Gas from the baghouse is discharged through an American Blower*
stack fan into the main zinc fuming plant stack.  The fan is driven by a
steam turbine which is controlled to maintain the draft in the zinc
fuming plant waste heat boiler within the proper range.  The fan was
originally designed to provide 3,540 act. m /min (125,000 acfm) at 100°C
(212°F) and 25 cm (10 in) WG static pressure drop.8
Maintenance and Operation

     Ten men per shift are assigned to the zinc fuming plant during
normal operation.  One man monitors and operates the fuming furnace and
waste heat boilers.  Two men are responsible for charging, tapping, and
cleaning tuyeres.  One man operates the steam soot blowers and air
lances for cleaning the boiler tubes.  The remaining personnel are
responsible for the kiln, baghouse, overhead crane and granulator
operations.

     Maintenance requirements include fairly routine practices for this
type of operation such as removing and cleaning dust deposits, keeping
the charge chute free of debris, and replacing worn or damaged equipment.
Of special significance to this study, however, are those practices
*  Brand name

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                                                               21
                         Table 3
DESIGN AND ACTUAL PARAMETERS FOR THE ZINC OXIDE BAGHOUSE
                BUNKER HILL LEAD SMELTER3,5
                        BAGHOUSE
   Manufacturer - Northern Blower
   Model - 78 DA
   Date of Installation - 1943
   Bag Area - 5,600 m2 (60,500 ft2)
   Air to Cloth Ratio (actual) - 3:1
   Pressure Drop (actual) - 10-15 cm (4-6 in) WG
   Pressure Drop (design) - 3 cm (1 in) WG
   Fractional Efficiency - Unknown
                            GAS
                                   •3
   Flowrate (actual) - 5,100 act. m /min (180,000 acfm)
   Temperature (actual - 66°C (150°F)
   Moisture (actual) - 1-4 vol%
                       PARTICULATE
   Inlet particulate concentration - Unknown
   Inlet particulate size - 0.7p (mass median diameter)

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                                                                       22
which affect the uncontrolled emission of participates.   These would
include maintenance of water jackets, boiler tubes, lance doors,  the
charging door, and the baghouse.

     The furnace water jackets form the walls, top and bottom of  the
zinc fuming furnace and water wall boiler.  These jackets are fastened
together and, as a result, gaps can form as expansion, contraction and
vibration occur within the furnace.  The Company has stated that  leaks
in the zinc fuming furnace are caulked on an "as needed" basis.7   There
is no inspection conducted to routinely locate furnace leaks.

     The tubes in the waste heat boiler are regularly lanced during each
8-hour shift to remove particulate deposits.  Particulate deposits
reduce steam production but more importantly, from a fugitive emission
standpoint, they reduce the negative draft available in the fuming
furnace.

     The lance doors for the waste heat boiler sections provide an
access for lancing the boiler tubes.  These doors are designed to seat
under negative draft and will leak under positive pressures.  In  addition,
these doors are exposed to varying temperature and mechanical shocks,
created as the doors are opened and shut and as the air lance is  inserted
and withdrawn.  As a result, the doors may not seat properly, thereby
allowing particulate emissions to escape under pressure through gaps.
The Company stated that no maintenance or inspection of the doors is
performed other than to make sure the doors are closed when not in use.
During the EPA inspections conducted in August 1976 and February  1977,
it was noted that the lance doors were leaking at several locations.

     The charge door is pneumatically operated and is purposely opened
only when the slag pots are being emptied into the furnace.  Particulate
emissions during fuming and tapping do result when the door does  not
close properly, either due to a malfunction by the pneumatic operator or

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                                                                       23
a buildup of solid material.  The Company has stated that these problems
are minimal and are corrected when they occur.7

     The zinc oxide baghouse affects fugitive emissions by limiting the
negative draft available in the fuming furnace and waste heat boiler.
This is caused by particulate buildup on the bags, and causes the
pressure drop across the baghouse to increase.  If the shake cycle on
the bags is increased, the baghouse pressure can be lowered and the
available draft is then increased.  During the February 1977 EPA inspection,
it was observed that the baghouse shake cycle was highly variable.  The
Company indicated that this was due to badly worn pneumatic shake valves,
but stated that these valves, as well as the rest of baghouse equipment,
were being rebuilt.
Particulate Sources
     Particulate emissions result from four major sources within the
zinc fuming plant.  These include the zinc fuming plant stack, the
granulating scrubber stack, the zinc fuming furnace charging area
stack, and the zinc fuming furnace building louver wall openings.


Main Stack

     The main stack receives the major gaseous and particulate emissions
from the zinc fuming furnace.  The quantity of these emissions is
expected to vary with state-of-heat of the furnace, reaching a maximum
during the charging/heating cycle and the early stages of the fuming
cycle and a minimum during the tapping cycle.  Particulate sizes and
concentrations can also expect to vary somewhat during the batch operation.
Data from stack sampling tests conducted by Valentine,  Fisher and Tomlinson2
indicate particulate concentration of 0.05 g/std.  m3 (0.02 gr/scf)  with

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                                                                       24
                              o
an average gas flow of 5,100 m /min (180,000 acfm) at the stack.2
Total participate emissions are estimated to be about 11 kg (24 lb)/hr.
Granulating Scrubber Stack

     The granulating scrubber and stack are operated intermittently,
about every 10 to 20 minutes during the zinc fuming furnace slag tapping
cycle.  The emissions consist of fugitive emissions from the tapping
launder, granulator particulate which are not caught in the scrubber,
and solids from the mist which is carried over from the scrubber spray.
Tests conducted by Alsid, Snowden and Associates9 indicate approximately
0.6 kg (1.3 lb)/hr particulate is emitted.
CharginQ Area Hood

     The charging area hood is located just above the fuming furnace
charge chute.  The hood is provided with a vent fan and a stack through
which the fumes exit to the atmosphere.  The largest portion of parti-
culate emitted through the charging area stack is generated during the
charging cycle.  During the charging/heating cycle, fugitive emissions
are released from the zinc fuming furnace from the slag pots and from
the molten slag as it is emptied into the furnace.  The proportionate
amounts generated by each contributor are difficult to estimate.  The
charging area stack also exhausts fumes from door and furnace leaks
throughout all furnace cycles.  The fumes in the charging area hood
emissions are expected to have an 0.7p mass median particle diameter.
Emissions from the charge area hood were measured by Valentine, Fisher
and Tomlinson.2  The emissions were found to be about 0.07 g/std. m
(0.03 gr/scf) at an average flowrate of 1,330 act. m3/min (46,800 acfm).
This amounts to 5.4 kg (12 lb)/hr.

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                                                                      25
Building Louvers

     Fumes which are emitted from leaks and the charging operation are
not always collected in the charging hood and, instead, are emitted
through the zinc fuming furnace building louvered wall openings.  These
louvers are located on the roof of the zinc refinery and have a total
            22
area of 46 m  (500 ft ).  Observations of the furnace operation indicated
that fumes typically are emitted through the building louvers approximately
10 minutes every half-hour.10  Fugitive emission measurements based on
particulate collected with a high-volume sampler were conducted by PEDCO,
Inc.10  These measurements indicated that the building louvers were
emitting about 9.6 kg (21 lb)/hr of suspended particulate at a flowrate
of approximately 4,960 act. m3/min (175,000 acfm).
Emission Rate

     The total mass rates of all solid materials charged and particulate
emitted from the zinc fuming plant are summarized in Table 4.  Based on
data presented in the table, the plant emits approximately 27 kg (58
lb)/hr of particulate at a charging rate of 27 to 29 m. tons (30 to 32
tons)/hr.

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                                                                       26
                                Table 4

            ESTIMATED MASS PATES FOR THE ZINC FUMING PLANT

                       BUNKER HILL LEAD SMELTER
MATERIAL CHARGED SKETCH PARTICIPATE SOURCES
Coal
	 7
Blast furnace
Slag .
1 ' /
ZINC
FUMING
PLANT
Main stack v
r
Granulating stack ^
/
Charging area hood v
/
Building louvers \
/
      Material
                                                  Mass Rate
Materials charged
     Coal
     Blast furnace slag
     TOTAL
Particulate emitted
     Main stack
     Granulating stack
     Charging area hood
     Building louvers
     TOTAL
m. tons/day
100
550-590
650-690
kg/hr
11
0.5
5.5
9.5
27
tons/day
110
600-650
710-760
Ib/hr
24
1
12
21
58

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                      V.  APPLICABLE REGULATIONS
     There are two  Idaho State air regulations which can be applied to
the operation of the zinc fuming furnace:   Idaho Regulation F for
control of fugitive dust, and Idaho Regulation H for control of particu-
late emissions from industrial processes.   The complete text of these
regulations can be found in Appendix B.  The discussion that follows
reviews the Company's compliance with Regulations F and H based upon the
observations made in this study.
REGULATION F - CONTROL OF FUGITIVE DUST

     Idaho Regulation F requires that "All reasonable precautions ...
be taken to prevent particulate matter from becoming airborne."  The
regulation further states that reasonable precautions may include, but
are not limited to, "... Installation and use of hoods, fansj and fabric
filters or equivalent systems to enclose and vent the handling of dusty
materials."  In addition to these guidelines, it was noted during this
study that the zinc fuming plants in East Helena, Montana, and El Paso,
Texas [Section VIII of this report] have or plan to install charging
emission collection and control systems.  The Bunker Hill Company has
made no effort to enclose or control fugitive charging emissions from
the zinc fuming plant operation.

     As a result of the regulation requirements and practices at other
zinc fuming plant installations, it is reasonable and prudent to assume
that, to comply with Idaho Regulation F, the Company must implement
fugitive emission controls.   There are various approaches which can be
used to control fugitive emissions, and some of these are discussed in
Section VI, of this report.   As a minimum,  however,  some means to
control  charging emissions will  be necessary.

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                                                                       28
REGULATION H - CONTROL OF PARTICULATE EMISSIONS FROM INDUSTRIAL PROCESSES

     Idaho Regulation H limits the rate of particulate emitted from any
process to the values shown in Table 5.  In this case, the zinc fuming
plant is considered a process.  Coal and blast furnace slag are the
solid materials which make up the process weight input.  The particulate
sources for which measurements have been made include the zinc fuming
plant stack, the granulator stack, the charging area stack and the
building louver openings.  Based on a process weight input of 29 m. tons
(32 tons)/hr [Table 4], the allowable emission rate is 18 kg (40 lb)/hr.
Actual emissions are estimated to be 27 kg (58 lb)/hr [Table 4].  However,
EPA Method 5 (40 CFR 60, Vol 36, No. 247, Dec. 23, 1971) measurements were
only made for emissions from the three stacks.  These emissions were 17
kg (37 lb)/hr.  If only the emissions determined by Method 5 are con-
sidered, then the zinc fuming plant does not violate Regulation H.
* E = 55.0(30)0>11-40, E = 40

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                                                                         29
                                  Table 5
                   ALLOWABLE RATE OF EMISSION BASED ON
                           PROCESS WEIGHT RATE*
                           Idaho - Regulation H
Process Weight
Rate
Ib/hr
100
200
400
600
800
1,000
1,500
2,000
2,500
3,000
3,500
4,000
5,000
6,000
7,000
8,000
9,000
10,000
12,000
tons/hr
0.05
0.10
0.20
0.30
0.40
0.50
0.75
1.00
1.25
1.50
1.75
2.00
2.50
3.00
3.50
4.00
4.50
5.00
6.00
Rate of
Emission
Ib/hr
0.551
0.877
1.40
1.83
2.22
2.58
3.38
4.10
4.76
5.38
5.96
6.52
7.58
8.56
9.49
10.4
11.2
12.0
13.6
Process Weight
Rate
Ib/hr
16,000
18,000
20,000
30,000
40,000
50,000
60,000
70,000
80,000
90,000
100,000
120,000
140,000
160,000
200,000
1,000,000
2,000,000 1
6,000,000 3

tons/hr
8.00
9.00
10.00
15.00
20.00
25.00
30.00
35.00
40.00
45.00
50.00
60.00
70.00
80.00
100.00
500.00
,000.00
,000.00

Rate of
Emission
Ib/hr
16.5
17.9
19.2
25.2
30.5
35.4
40.0
41.3
42.5
43.6
44.6
46.3
47.8
49.0
51.2
69.0
77.6
92.7

Interpolation of the data in this table for process weight rates up to 60,000
Ib/hr shall be accomplished by use of the equation E - 4.10 p°-67^ <#& inter-
polation and extrapolation of the data for process weight rates in excess of
60,000 Ib/hr shall be accomplished by use of the equation:

             E = 55.0 JT'    - 401 where E = rate of emission in Ib/hr
                         and P = process weight rate in tons/hr.

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                VI.   PARTICULATE COLLECTION AND CONTROL
     The  purpose  of this  section  is  to review the alternatives for con-
 trolling  fugitive emissions from  the zinc fuming plant.  As discussed in
 Section V,  it  is  apparent that the Bunker Hill Company is not complying
 with Idaho  Air Regulation F requiring that "reasonable precautions... be
 taken to  prevent  partiaulate from becoming airborne. "  This section
 reviews some of the potential methods the Company could implement to
 comply with the regulation.
OPERATION AND MAINTENANCE

     Operation and maintenance modifications, as discussed here, include
procedural changes which could be implemented without changing existing
equipment.  Occasionally, by altering maintenance and operating practices
it is possible to significantly reduce fugitive emissions.

     Maintenance modifications reviewed in this study were those which
would directly reduce fugitive emissions.  Specifically, the area which
could be improved most and for which the Company has been cited by the
                                £                                J
EPA in a 113 Notice of Violation  is the maintenance of waste heat
boiler doors.  These doors should be more frequently inspected by the
Company with the sole purpose of noting significant fugitive emissions,
and the latch mechanism tightened as necessary.   Also, as part of the
routine inspection, the physical  condition of the zinc fuming furnace
   Clean Air Aot3  as Amended 42 USC 1857 (c).

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                                                                    31
should be examined.  These practices could be achieved with a minimum
increase in manpower requirements.   It should be noted, however, that
the waste heat boiler doors are designed to operate at negative pres-
sures.  If the boilers are under positive pressure, no amount of main-
tenance will prevent door leakage.

     The zinc fuming furnace and the waste heat boiler are designed to
operate under negative pressure.  During the EPA-conducted inspections,
however, several leaking doors and various emissions from the furnace
were observed signifying that the fuming furnace and portions of the
boiler are under positive pressure.  Consequently, operating modifica-
tions that would increase the available draft should be considered.
These could include operating the baghouse shaker on a more frequent
cleaning cycle and increasing the frequency and thoroughness of air
lancing the boiler tubes.

     More frequently and/or prolonged baghouse cleaning would lower the
pressure drop across the bags and, therefore, lower the pressure at
the zinc fuming furnace.  The drawbacks to this approach are increased
bag wear and the possibility of "puffs" of particulate occurring as
cleaned bags are brought on line.  As a result, the bag cleaning cycle
should be optimized for maximum particulate control.  At present, the
disrepair and poor condition of the existing baghouse may further limit
the effectiveness of this approach.

     The Company currently has a program to routinely air lance the
boiler tubes.  It is possible, however, to increase the frequency of
this practice by limiting some of the collateral assignments of the
lancer operator.  This approach, as in the case of changing the baghouse
cleaning cycle, must be optimized with other operational requirements.

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                                                                    32
     Although the above described operating and maintenance modifications
can reduce fugitive emissions, they alone are not likely to enable the
plant to comply with Idaho Air Regulation F.


PROCESS MODIFICATIONS

     In that process modifications are considered to include equipment
changes, they are differentiated here from maintenance and operating
modifications.  For the zinc fuming operation, the most feasible process
modification involves increasing the draft at the furnace.  This would
reduce fumes presently escaping from the furnace and the waste heat
boiler and which subsequently become uncontrolled fugitive emissions.
The furnace draft can be increased by increasing the static pressure
drop provided by the stack fan and/or by reducing the pressure drop in
the system, most likely at the baghouse.

     The Company has indicated that it is currently rebuilding the
existing steam driver for the stack fan so that it will operate con-
tinuously at 640 rpm.7  The original fan was designed to operate at 509
rpm.  The fan can then generate 5,130 act. m /min (181,000 acfm) at 25
cm (10 in) WG whereas the original fan was designed for 3,540 act.
m3/min (125,000 acfm) at 25 cm (10 in) WG.  The characteristic fan
curves are shown in Figure 4.  The Company has stated that the stack fan
with rebuilt driver will be operating with the largest diameter impeller
and at the highest speeds suitable for this model.7  Therefore, to
further increase available static pressure, an additional fan would have
to be installed in series with the existing stack fan.  Because of
inadequate space near the existing stack fan, a new fan could be located
between the zinc oxide cooling tower and the zinc oxide baghouse.   It
should be designed so that both fans could be operated to provide  an
additional 3 to 5 cm (1  to 2 in) WG of static pressure.

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                                                                                  33
10.0.
 5.0-
                                                    625  RPM
                   20
                Figure  4.
      40              60
            % CFM  (in thousands)
80
100
                                                                 Temperature = 212°F
                                                                   Elevation = 2,300 ft
 Fan Characteristic Curves  for  Zinc Fuming Plant
Stack Fan, Bunker Hill  Lead  Smelter

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                                                                    34
     The Company also indicated that it is replacing the existing zinc
oxide baghouse with a similar system having the same basic capacity and
components.7  This is not expected to reduce the baghouse pressure drop
below the current7 4 inch WG range.  To reduce the pressure drop, an
additional baghouse section could be installed.  If a section similar to
those now present were erected, it is estimated that the pressure drop
would be reduced by 1 t.o 3 cm (0.5 to 1 in) WG.


CHARGING EMISSIONS COLLECTION

     Maintenance, operational, and process modifications can reduce the
amount of fugitive particulate emissions from the zinc fuming plant;
however, it is unlikely that these changes will provide the extent of
control necessary to meet Idaho Air Regulation F.  At other zinc fuming
plant installations in the United States [Section VIII] it has been
necessary to develop means for collecting and removing the emissions
generated during the charging cycle.  In this subsection alternatives
for collecting charging emissions are discussed, while in the next
subsection particulate removal alternatives for the charging emissions
are reviewed.

     A very critical part of reducing particulate emissions to accepted
levels is to have a properly operating fume collection system.  The
existing collection system consists of a 2.4 m x 3.7 m (8 x 12 ft) hood
located above the furnace charge door [Figure 5].8  The hood is con-
nected to a vent fan and stub stack through which emissions are dis-
charged.  The hood does not adequately collect charging emissions for a
number of reasons.  Basically, the hood is too small and too distant
from the charge area for the available vent fan capacity and for the
magnitude of charging emissions.  As a result, fumes escape around the
hood and out through the louvered building openings.  It is estimated,
  See Appendix C for calculation.

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                                                               35
                                                              0.* _ ff.y » „• f XV ^«' < ft *W* *•-!
Figure 5.  Elevation Drawing  Showing Location of Existing
       Charge Area Hood for the  Zinc Fuming Plant
                Bunker Hill Lead  Smelter

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                                                                    36
based on fugitive emission testing,  that more fume escapes  through  the
building openings than is collected  by the present charging area  hood.

     To improve fume collection many alternatives are available.   Four
alternatives with subsequent ventilation and hooding requirements are
outlined in Table 6.  Restrictions and guidelines used in establishing
these alternatives are as follows:

   o The hooding system must allow for the crane access so that blast
     furnace pots can be properly emptied into the charging hopper.
   o The hooding system must take into account the open nature of the
     building and the resulting problems with cross drafts disturbing
     ventilating air flow.  When possible, curtains should be used to
     restrict air flow interferences.
   o A canopy-type hood is considered more suited to the control  of hot
     processes where sudden surges of hot gases and vapors occur.
   o An "appropriate" fume collection system should be capable of re-
     moving 70% to 90% of the fugitive emissions from the zinc fuming
     charging operation.

     The most desirable alternative is considered the one requiring less
air volume and, hence, a smaller particulate collection system and fan.
As a result, the dual canopy hood system designed as Alternative A [See
Section VII] was selected for the system despite some drawbacks due to
restricting crane operation.  With this alternative, the crane operator
would have to be careful in bumping and moving the slag pots while these
were beneath the collection hoods.  A schematic of Alternative A is
shown in Figure 6.  The emissions to the particulate removal system
would have the following estimated characteristics:

          Flow                     2,270 act. m3/min  (80,000 acfm)
          Temperature              50 to 70°C (120 to  160°F)
          Moisture, Volume         1% to 3%
          Particle  Inlet loading   14 to 28  kg/hr  (30  to 60 Ib/hr)
          Particle  Size            0.7  M MMD

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                                                                                              37
                                               Table 6

     ALTERNATIVES FOR PROVIDING APPROPRIATE VENTILATION OF THE ZIHC  FUMING FURNACE CHARGING AREA
                                      BUNKER HILL LEAD SMELTER
Alternative
Arrangement
Locations
Estimated Ventilation
   Air Requirements
                                                                                        Comments

A

Modified canopy
each approximately
2.4 x 2.1 m
(8x7 ft)
m /min
Side-by-side 2,200
hood located
above charge
hopper 0.6 m
(2 ft) space
between hoods
to allow over-
head crane access.
cfm
80,000 Some restriction and
obstruction to view of
crane operator. Side
enclosed to minimize
drafts.
              Dual side draft
              hoods, each
              2.4 x 2.7 m
              (8x9 ft)
              Single canopy
              hood 6.4 x 5.5 m
              (21 x 18 ft)
              Building ceiling
              collection
                  On each side of
                  charge hopper,
                  hoods facing one
                  another.
                  Hood located
                  approximately
                  4.9 m (16 ft)
                  above charge
                  hopper at elevation
                  of existing hood.

                  Top of zinc fuming
                  building
                       3,900     140,000
                       7,600
              270,000
                      11,800     420,000
Release of fume into
zone of very rapid air
motion expected to
require relatively high
capture velocities.

Subject to high cross
draft interference.
Large inlet velocity
and ventilating rate
will be required.
                           This approach is
                           practical only if the
                           entire top of zinc
                           funning building can
                           be closed to form a
                           hood.  Large venti-
                           lation rates will be
                           required.

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                                                                      38
                                                              FURNACE WALL
                              PLAN
HOODS
                                                                  •CRANE RAIL AXIS
                                                        APPROXIMATE
                                                            SCALE
                                                           1"  =  4'
                              ELEVATION
Figure  6.  Sketch of Hooding Arrangement for Zinc  Fuming  Furnace
      Charge Area (Alternative A),  Bunker Hill  Lead  Smelter

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                                                                     39
 CHARGING EMISSIONS CONTROL

      Once the charging emissions  from the zinc  fuming furnace  are
 adequately collected,  the fumes must  be  removed in  an appropriate  par-
 ticulate removal  device.   Table 7 shows  the  alternatives  that  were
 evaluated for treating the charging emissions.   It  was found that  the
 existing granulating  scrubber, the existing  zinc  oxide baghouse, the
 existing main lead smelter baghouse,  a new wet  scrubber,  and a new
 electrostatic precipitator (ESP)  were not acceptable  approaches for
 technical  reasons.  The best devices  for controlling  the  charging
 emission appear to be  a new baghouse  designed specifically for the
 charging emissions, an expanded zinc  oxide baghouse,  or an expanded
 main  baghouse.  The gas collection systems discussed  previously
 (including hoods,  ducting,  and a  vent fan) will be  required for each
 of  these alternatives.
New Baghouse

     A new baghouse designed for the charging emissions could be ex-
pected to have acrylic bags, arranged in a multichamber unit with
       2           ?
3,700 m  (40,000 ft ) of bag area.  The unit could use a shaker cleaning
system and could be designed for 99+% efficiency.  It could be located
nearby (e.g., on the roof) provided that any support structure could be
upgraded as necessary.  Auxiliary requirements would include a fan,
ducting, isolation gates, instrumentation and a solids removal system.
Expanded Zinc Oxide Baqhouse

     The existing zinc oxide baghouse system could be modified by the
addition of a second stack fan and an additional  baghouse section.   The
ventilation air from the furnace charging area could be introduced  at

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                                                                                                    40
                                               Table  7

 ALTEHUATIYES FOR COLLECTING AlID COHTROLLUIG PARTICULATE FROM ZIllC FUMING FURNACE CHARGING EMISSIONS
                                      BUNKER HILL LEAD SMELTER
   Control Device
    Alternative
 Estimated Reduction
in Fugitive Emissions
  Technical
Acceptability
Technical
 Review
Existing granulating
  scrubber
Existing zinc oxide
  baghouse
       10-501
       30-702
Existing main baghouse

New baghouse                    70-90%
New scrubber
       60-902
New ESP
       60-902
Modified zinc oxide
  baghouse
Modified main baghouse
       80-902
       80-902
Not acceptable   The present scrubber is not large
                 enough for the gas volume to be
                 treated and, further, is an inertia]
                 impaction device which is not
                 efficient for sub-micron participate.
Not acceptable   The existing zinc oxide baghouse is
                 undersized for the current con-
                 ditions (3:1 air-to-cloth ratio,
                 2:1 desired).  Additional flow would
                 further increase baghouse pressure
                 drop and increase furnace pressure,
                 thereby increasing leakage.

Not acceptable   The existing main baghouse is inade-
                 quate and is currently being expanded.

Acceptable       A baghouse would provide good particu-
                 late control in this application.
                 Baghouses are used throughout the
                 smelter and the Company snould be
                 well-acquainted with their operation.

Not acceptable   The low grain loading and small
                 particle size would require a high-
                 energy venturi (^100 cm WG AP) for
                 this application.  This fact and the
                 need to handle a blowdown slurry are
                 large drawbacks to the use of a
                 scrubber.

Not acceptable   Technically, an electrostatic pre-
                 cipitator could be used in this
                 application.  However, the lack of
                 experience of ESP's in similar zinc
                 fuming furnace operations would hinder
                 proper design and may lead to over-
                 conservative sizing criteria and
                 higher costs.  Also, the Company has
                 had limited experience with ESP
                 operations.

Acceptable       The addition of another zinc oxide bag-
                 house section and additional stack
                 fan capacity not only provides a means
                 of treating charging emissions but also
                 can increase the draft in the furnace
                 and waste heat boiler.  This reduces
                 fugitive emissions from these sources.

Hay be           The main lead smelter baghouse is cur-
acceptable       rently being increased in capacity to
                 handle the lead smelter blast furnace
                 upsets.  Due to the unpredictable nature
                 of such upsets it is premature to con-
                 sider or define further modifications
                 which would allow the baghouse to treat
                 fuming furnace charginq emissions.   This
                 Should be analyzed after the currently
                 planned modifications are put into operation.
                 From preliminary observations it appears
                 that there is adequate capacity for treat-
                 ing charging emission for a large fraction
                 of the time with little additional  modifi-
                 cation to the main baghouse.

-------
the inlet to the expanded zinc oxide baghouse.   Since this air would
typically approach ambient conditions there would be reduced need for
cooling air.  As a result, the existing cooling air louvers at baghouse
inlet could be partially closed.   The actual additional  flowrate to the
zinc oxide baghouse would then be much less than the 2,270 act. m/min
(80,000 acfm) nominally provided  by the charge  area ventilation fan.
This approach has the added advantage of increasing the  available draft
in the fuming furnace and waste heat boiler. Therefore, besides re-
ducing charging emissions, other  zinc fuming plant fugitive emissions
would be reduced.  Auxiliary requirements for implementing this modifi-
cation would include a ventilation fan, ducting, isolation gates,
instrumentation and a solids removal system.
Modified Main Baghouse

     The Company is currently in the process of expanding the main bag-
house to accommodate upsets from the lead smelter blast furnaces.7  The
planned baghouse modifications will  accommodate a peak flowrate of
             Q
17,000 act. m/min (600,000 acfm) and a normal  flowrate of 11,300 act.
 o
m/min (400,000 acfm).  There will be seven baghouse sections providing
                                   o
an air-to-cloth ratio of 0.6 act. m/min per square-meter cloth area
(1.8 acfm per square-foot cloth area) at normal flowrates.  The Company
has indicated, however, that the blast furnace  upsets are highly unpre-
dictable.  The Company also has indicated that  the structural require-
ments for the baghouse will be just adequate when the planned expansions
are made.  Consequently, it would be imprudent  at this time to suggest
further main baghouse modifications.  It does appear, however, that
after the planned changes are made,  sufficient  capacity will  be avail-
able in the baghouse to accommodate the zinc fuming furnace charging
emissions.  The few additional modifications necessary to allow the
baghouse to treat these emissions should be insignificant from an
engineering and cost standpoint.

-------
                          VII.   COST ANALYSIS
     The alternatives for reducing fugitive emissions  at the zinc  fuming
furnace include operation, maintenance,  process,  and particulate collec-
tion and modifications.   The operation and maintenance changes  pre-
viously identified could be implemented  with very little cost.   Process,
and collection and control modifications,  however, will  involve instal-
lation and operation cost investments.  Preliminary cost estimates for
these alternatives are shown in Appendix C.

     Table 8 shows the installed costs and operating costs  required  for
five process and/or control equipment modifications based on preliminary
NEIC estimates.  The alternatives can be further  summarized as  follows.
                                        Installed   Yearly
                                          Cost     Operating
               Alternative                           Cost
                                          ($)         ($)
A
B

C

D


E



Additional stack fan
Additional zinc oxide
baghouse section
Charging emission
control - new baghouse
Charging emission
control - expanded
zinc oxide baghouse
Charging emission
control - modified main
baghouse [see Note 4,
Table 8]
64,000

195,000

370,000


320,000



57,000
22,000

52,000

75,000


83,000



14,000

-------
                                                                       Table 8

                                 smiua OF COSTS FOR ALTERNATIVES TO REDUCE zinc FUMING FURNACE FUGITIVE EMISSIONS
                                                              BUNKER HILL LEAD SHELTER
\ A
^^Alternatives Additional
x. Stack Fan
B
Additional
Zinc Oxide
Baghouse Section
C
Charging Emission
Control -
New Baghouse
0
Charging Emission
Control -
Expanded Zinc Oxide
Baghouse
E
Charging Emission
Control-
Modified Main
Baghouse
                                                             DESCRIPTION OF ALTERNATIVE
INSTALLED COST (1C)
1.Collectors
2.Auxiliaries
  (hood, fans,
   ductwork, etc.)
3.Installation

   TOTAL
                       Add an  additional stack
                       fan between  the  zinc
                       oxide cooling  tower and
                       the baghouse.  The fan
                       should  be  nominally
                       capable of 5,000 act.
                       m3/min(180,000 acfm)
                       at 12 cm WG (5 in WG).
                               $54.000


                               $10,000

                               $64.000

                    tttt
                                                Add an additional
                                                section to the
                                                to the existing zinc
                                                oxide baghouse.
                                                The section would be
                                                identical to one of
                                                of the existing
                                                sections.
$180.000
 $25,000
 $90,000
$195,000
YEARLY OPERATING COSTS
Direct
1.Operating Labor
  Operator (S5/hr)
  Supervisor (S8/hr)
  Benefits (25X of labor)
2.Maintenance                     $1.500
  (labor, materials and
  replacement parts)
3.Electricity                    $11,500
  (0.008c/kwh)

Indirect
1 .Depreciation                    $6,500
  (10%  1C)
2.Taxes and  Insurance             $2,000
3.Plant Overhead                    $500
  (50% of  labor and
    maintenance)
    TOTAL  (nearest thousand  $)    $22,000
                                                       $15.000
                                                       $19,500

                                                        $6,000
                                                        $7,500
                                                       $52,000
                   Install  charging
                   area collection
                   hoods, ductwork,  a
                   ventilation fan,
                   a separate baghouse
                   and necessary
                   auxiliary
                   equipment.
                                                                             $200,000
                                                                              $50,000
$120,000
$370.000
                         $2.000
                           $500
                           $500
                        $12.500
                                                                               $3.500
                         $37,000

                         $11,000
                          $7.500
                         $75.000
                  Install charging area
                  collection hoods, a
                  new ventilation fan,
                  and necessary duct-
                  work  to route the
                  emissions to the
                  inlet of  the exist-
                  ing zinc  oxide bag-
                  house section similar
                  to those  described in
                  alternatives A and B.


                       $80,000
                     $120.000
$120,000
$320.000
                    Install charging area
                    hoods, a ventilation
                    fan, and necessary
                    ductwork to route the
                    emissions  to  the inlet
                    of  the modified main
                    lead  smelter baghouse.
                  ttt
$37.000


$22.000

$57.000
                       $17.000


                       $16.000



                       $32,000

                        $9,500
                        $8,000



                       $83,000
                            S500


                          $4,500



                          $6,000

                          $2.000
                            $500



                         $14,000
       For support calculations,  see Appendix C.
       All coeia are  1-30% prelvnnary  estimates.                                       „....,»  i	 i „
       Tr.e coate for  Alternative  E assure  that  the modified main baghouee can be uaed for sine fuming plant charging
       emissions uith only ninor  rradificationa.                                                           .   .         ,
 tttt  All operating  costs assume a 701 annual  operating factor uith the exception of the nea baghouse emission control
       eye tern imihich a 33%  operating  factor ia used.
  t
 tt
ttt
                                                                                                                                                              CO

-------
                                                                   44
     In reviewing these estimates it is important to note that the
actual reductions in charging emissions if alternatives A or B are
selected are unknown.  It is expected that these alternatives, in them-
selves, will not allow the fuming furnace operation to achieve compliance
with Idaho particulate regulations.  However, either of the alternatives
should result in a significant decrease in charging emissions.  By
reducing charging emissions by alternatives A or B, it is possible to
reduce the particulate load and capture velocities required for the
collection and control of the remaining charging emissions.  If the
volume and efficiency requirements for controlling the remaining charging
emissions are reduced, then the costs of charging emission controls
(Alternatives C, D, and E) may be substantially decreased from the costs
shown in Table 8.

     All cost estimates developed in this study should be considered as
preliminary (+30%) estimates.  Installed costs include engineering,
installation and equipment costs but do not include costs associated
with production time lost during installation.  Annual operating costs
include direct cost, such as maintenance, replacement parts, etc., as
well as indirect costs incurred in depreciation, taxes and insurance.

-------
                   VIII.   RELATED  INDUSTRY  EXPERIENCE
      Based  on  a  survey  made during  this study, there are only two other
 lead  smelters  located In  the United States which have zinc  fuming opera-
 tions.   These  are  the ASARCO lead smelters in East Helena,  Montana, and
 El  Paso,  Texas.  The NEIC conducted inspections of the East Helena
 facility on July 22, 1976 and of the El Paso facility on February 3, 1977,

      The  following  subsections present a short review of the process,
 emission  observations,  and fugitive emission controls noted during
 inspections at these installations.

 ASARCO  -  MONTANA*

 Process  Description

      The  ASARCO  lead smelter is about one-quarter mile south of East
 Helena, Montana.  Built in 1888, it has been modified many  times since
 then.  A  custom  smelter,  it specializes in processing high  sulfur-lead
 concentrates and zinc residues from locations throughout the world.

      A block diagram showing the overall smelter operation  is presented
 in  Figure 7.   An updraft  sinter machine receives concentrates, residues,
 limestone,  silica and coke and produces a granular product  (sinter)
 suitable  for charging to  a blast furnace where it is reduced with coke
 and scrap iron to produce a crude lead bullion.   The crude bullion is
 processed at a dressing plant to produce a bullion-grade lead ready for
 final refining.  Silver and gold are removed during refining.   Copper
matte, a speiss (Cu, As, Sb),  and blast furnace  baghouse dust are shipped
as products requiring further processing.
*  Information in this section is derived from reference  11.

-------
                                                            46
                              .~,.~r,^j,  w- •  --. 	,
                                           G /SO -iCf" PI PCS -/Z.'

                                         7      )   Auxr
                                                          ~
             &.'Htkj&f-SjJT $ CAP- 30073*1 f>. ZSf/k
                - <        -

Figure  7.  Lead Smelter Plant  Flow Sheet

      ASARCO,  East Helena, Montana

-------
                                                                     47
      The zinc fuming plant was designed by Anaconda and constructed in
 1927; ASARCO purchased the plant in 1972.  This plant is essentially a
 batch operation.  The purpose of the zinc fuming plant is to smelt slag
 from the blast furnace and mined slag from a storage pile producing zinc
 oxide, lead oxide, and copper matte.  The slag enters a furnace with a
 coal and air mixture where it is heated by combustion of the coal under
 reducing conditions.  The zinc and lead initially present in the slag
 are reduced, vaporized, re-oxidized and carried with the offgas through
 a cooling system by an induced draft fan.  The offgas passes through a
 balloon flue and enters a baghouse where the lead and zinc oxide fumes
 are removed.  In addition to the main offgas, the baghouse receives
 fumes which are vented from the hooded zinc fuming furnace charging and
 tapping areas.   The exhaust gas from the baghouse is discharged to a
 stack.   The slag from zinc fuming furnace is tapped into a gas-fired
 holding furnace where copper matte and waste slag are separated.   The
 total  cycle time for the  process is about 165 minutes.   A process flow
 diagram of  the  zinc fuming plant, prepared  during the inspection, is
 shown  in Figure 8.

     Table  9 shows  the  operating design  data for  zinc fuming  plant
 operation.   The  plant processes  approximately 12  m.  tons/hr of  blast
 furnace  slag and 7.5  m. tons/hr  of  mine  slag,  producing  approximately
 3.0  m.  tons/hr  of zinc  and  lead  oxide  fume.   The  furnace  is a bolted
 water-wall  furnace  with a  capacity  of  approximately  55 m.  tons.   The
 zinc fuming  plant handles  seven  to  eight  charges  per day.


 Process and  Emissions Observations

     The zinc fuming furnace was observed throughout  its full cycle of
 operation during  the July 22, 1976  inspection.  Observations were made
 as to how each of the process steps was conducted, where fugitive
 emissions occurred, how the emissions were collected and/or controlled,
 the effectiveness of the collection/control  systems, and what factors
appeared to most influence the emissions and their control.

-------
                                                 48
AIR—p-
AIR — >•
COAL *"
SOLIDS
ZINC F
i
TERTIARY
AIR BLOWERS


Dl ACT
FURNACE
AIR BLOWERS
	 FURNACEl
SLAG A
MINED
SLAG
r _u — — I
tl
ZINC FUMING SPENT SLAG | HOI
COAL
PULVERIZERS
AND FEEDERS
RECYCLED TO
UMING FURNACE



| FURNACE

-• 	 - v - ll
1^
JT
WATER-COOLED 1 J^p
j PI iir ] uullr

fM PANFI F



\
FUME U-TU
M GAS CO

I
LUE J
TUE 1
j
VENTILATION
FAN
T
BE !
OLER I
1 FUGITIVE
	 J CHARGING;
HOODS
r
BAGHOUSE
FAN
•
LOADING

'
OUSE

.DING
JRNACE
COPPER
MATTE
TO
TACOMA
EMISSIONS FROM
'TAPPING AREA
Figure 8.   Zinc Fuming Plant Flow Sheet
     ASARCO,  East Helena,  Montana

-------
                                                               49
                           Table 9

              OPERATING AND DESIGN INFORMATION
             ASARCO - MONTANA ZINC FUMING PLANT11
                          OPERATING

Average cycle times                          (minutes)
     Charging/heating                          60-75
     Fuming                                    60-90
     Tapping                                   10-15

Charges/day                                     7-8

Material flowrates                      (m.tons/hr) (tons/hr)
     Blast furnace slag                    12.0       13.2
     Mine slag                              7.5        8.3
     Coal                                   4.3        4.7
     Fume collected                         3.0        3.3

Zinc/lead recovery                           (% by weight)
     Average lead in input slag                 1-4
     Average lead in output slag                 0
     Average zinc in input slag                 12
     Average zinc in output slag                <2

                                                       3
Air flowrate, charging                       450 act.  m /min.

                           FURNACE

Type                                         water-wall (bolted)
Capacity                                  55 m.tons     61 tons
Dimensions                       6.4 x 2.4 x 5.2 m (21  x 19 x  17  ft)
Tuyeres                           20/side on 30 cm centers, 14 cm
                                  from bottom, 4 cm diameter
Charging       Hot slag is charged through charge hole on south side
               of furnace approximately 2.4  m from top of furnace.
               Cold slag is charged by conveyor into a chute at the
               top of the furnace on the east side.

-------
                                                                     50
      The zinc fuming furnace is charged with 4.5 m.  ton (5 ton)  capacity
 pots of blast furnace slag which are emptied by crane into a  furnace
 charging hole and with mined slag which is  discharged from a  continuous
 conveyor into a second charging hole near the top of the furnace.
 Pulverized coal and  air are blown through two rows of tuyeres into  the
 bottom of the furnace.  The crane lifts each pot over the charging  hole
 and swings it back and forth,  banging the pot against a bumper located
 above the opening.   The pots are handled this way to break up skulls, or
 hardened material, which are formed  as  the  pots cool.   The pots  observed
 were completely empty after the operation and no "pot shell"  was returned
 to  the blast  furnace.   It took about 3  to 5  minutes  to empty  each pot.
 Seven to eight pots  are emptied into the furnace for a given  charge.

      Emissions of  fumes result from  a number of sources  during the
 charging/heating cycle.   The most significant of these sources observed
 were the charge hole  and the slag pots  which  emitted  fumes  as  they were
 emptied  during the charge.   Other sources of  emissions were the  cold
 (mined)  slag  entry chute as  the material  was  charged,  and  the  leaks  in
 the  furnace walls.  These  leaks were  much more  significant  during charging
 than during the subsequent  steps  of  the  process  cycle.  This was probably
 due  to the fact that  a  greater  furnace  pressure  occurred during  the
 charging period.

     The  fumes  from the  hot  slag  charging operation are collected by an
 overhanging hood with an air intake over the furnace top.  The degree of
 fume collection appeared to vary with the individual  crane operator's
 technique.  During the first observed charge, emptying of the pots  was
 less vigorous, and resultant fume collection approached 90% to 100%.
 However, during the second charge, the pots were more abruptly handled
as they were emptied  and fume collection dropped off to 50% to 60%  in
some instances.

     Also providing some measure of reducing fume generation above  the
hot slag charge hole  were two air nozzles which direct air into the

-------
                                                                     51
charge hole opening.   The nozzles appeared to have had varied effective-
ness, depending on the conditions within the furnace and the presence or
absence of slag material  which had hung up in the charge opening.
Besides operator variation in handling the pots, other factors which
influence the magnitude of the charge emissions are furnace pressure
fluctuations, ventilating air suction pressure, ventilating air flow
rate, the physical arrangement of the duct, and how rigidly the skull
had set up in the pot.

     Some fugitive emissions evolved from the cold slag charging chute
at the top of the furnace.  These emissions are reduced by an air nozzle
which in this case was located just inside the furnace.  This mechanism
did not appear to be operating correctly as significant fumes were
observed to be escaping.   The leaks from the furnace walls were uncon-
trolled.

     The charging/heating cycle takes approximately 60 to 75 minutes.
The cycle is reportedly longer than for other zinc fuming furnaces;
since ASARCO stockpiles only a few pots of blast furnace slag prior to
beginning a charge, additional pots must be awaited from the blast
furnace as the charge is completed.

     After all the slag has been added to the furnace, the furnace
enters a fuming stage in which as much zinc is removed from the molten
bath as is feasible.   In this stage, the amount of air added is decreased
and the amount of pulverized coal added is increased compared to that
added in the charging stage.

     Tertiary air, to oxidize the lead and zinc vapor, is added through
the two nozzles directing air into the charge opening and through the
single nozzle directing air into the mined slag chute.  The fuming cycle
takes from 60 to 90 minutes.

-------
                                                                     52
      Fugitive emissions were  observed  to  emanate  from  the  furnace walls.
 The  walls  of the  furnace  are  a  series  of  water  jackets which are bolted
 together.   In some  cases,  the gaps  between  the  furnace jackets  caused
 significant emissions; these  gaps were wide enough  to  allow a view of
 the  flames from the molten bath inside.   As the furnace  pressure fluctuates,
 the  jackets vibrate,  thereby  allowing  fumes to  escape.   The Company
 indicated  that the  seams  are  caulked with asbestos  rope, Kaolwood* rope
 or Si lite* 100 sealer as  needed.

      The quantity of  emissions  appears to be a  function  of maintenance
 practices.   In some cases,  the  furnace leaks were in areas of extremely
 tight working space and proper  caulking would be  understandably difficult.

      At the end of  the fuming cycle, the  furnace  is tapped through a set
 of two tapping holes  to remove  spent slag.   A hood  is  lowered over the
 slag tap launder  and  appropriate dampers  are positioned  to allow the
 ventilating air to  take suction on  the tapping  line.   During the inspection
 it took about 10  to 15 minutes  to tap  the zinc  fuming  furnace.

      The fugitive emissions from the tapping operation were relatively
 minor.  There was some escape of fumes between  the hood  and the furnace.


 Fugitive Emissions  Controls

      The fugitive emissions resulting  from  the  zinc fuming, charging,
 and  tapping operation are collected by hoods  over the  fuming and tapping
 areas, respectively.  The charging area uses  an overhanging hood with a
 collection  area of  11 m  (118 ft2) and an inlet gas velocity of 64 m
 (211  ft)/min.  The  ventilation  flowrate is  730 act.  m3/min (25,890 acfm)
-at 90°C and  650 mm  Hg.
   Brand name

-------
                                                                     53
     The fumes which are collected in the hood are vented to the suction
of the zinc oxide baghouse fan.  The baghouse is a shaker-type baghouse
with Nomex* bags.  The bag area is 9,100 m2 (98,400 ft2).  The total
                                         o
flowrate through the bags is 4,600 act. m /min (164,000 acfm) with a
reported particulate removal efficiency of 99.7% by weight.

     The Company has also reported that some reduction in fugitive
emissions has been accomplished by increasing the available draft at the
furnace.11  The Company has done this by installing a larger diameter
impeller in the baghouse fan.  This also required increasing the fan
motor from 380 to 530 kW (500 to 700 hp).

     ASARCO has stated that the ventilation hoods, ductwork, new venti-
lation fan, and larger baghouse fan impeller and motor were installed at
a cost of $236,000.  The ventilation fan and ductwork were put in service
in March 1974.  The installation and remodeling of the hoods and the
installation of the larger baghouse fan impeller and motor were completed
in December 1975.

     The Company has indicated that future plans are to improve the
baghouse fan volume and extend the charge area hood.  Improving the
baghouse fan volume will, in part, be accomplished by reducing the
pressure loss at the junction where the ventilation air flow joins with
the main offgas stream.  No information was provided as to the projected
completion dates and costs of these modifications.
 *  Brand name

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                                                                     54
 ASARCO  -  TEXAS*

 Process Description

     The  ASARCO  lead  smelter  is  inside  the city limits of  El Paso,
 Texas.  It was originally  built  in  1887 but  has undergone  extensive
 modifications since then.  A  custom smelter,  it processes  ores from
 locations throughout  the world.

     A  block diagram  showing  the overall smelter operation is presented
 in  Figure 9.  Six updraft  sinter machines receive concentrates, residues,
 limestone, silica and coke and produces a granular product (sinter)
 suitable  for charging to a blast furnace where it is reduced with coke
 and scrap iron to produce  a crude lead  bullion.  The crude bullion is
 processed at a dressing plant and casting to  produce a 99% lead product
 which is  ready for final refining.   Copper matte, and a speiss (Cu, As,
 Sb) are transferred to the copper department  for further processing.

     The zinc fuming  plant was constructed in 1948.  This plant is
 essentially a batch operation in which  hot slag from the blast furnace
 and cold slag held over from earlier operations are smelted to produce
 zinc oxide, lead oxide, and copper  matte.  The slag enters a furnace
 with a  coal and air mixture and is  heated by combustion of the coal
 under reducing conditions.  The zinc and lead initially present in the
 slag are reduced, vaporized, re-oxidized and carried with the offgas
 through a cooling system by an induced draft fan.   The offgas passes in
 series  through a waste heat boiler, balloon flue,  cooling tower and
 baghouse.   The baghouse exhaust gas is discharged  to a stack.  The fume
 collected in the flues, cooling tower and baghouse are treated in a
 deleading kiln which separates the  lead and zinc oxides.   The slag from
 the zinc fuming furnace is tapped into a gas-fired holding furnace where
 copper matte and waste slag are separated.
*  Information in this section is derived from reference 12.

-------
                        PURCHASED  ORES AND  CONCENTRATES  (26%  LEAD)
                                                                                     55
                            SIX  DWIGHT  LLOYD  SINTERING MACHINES
                  GASES
             D &  L BAGHOUSE
             1760 DYNEL  BAGS
                                                            Silt
TER
                                                        BLAST FURNACES
18 in DIA X 30 FT LONG
1 » t
I SLAG LEAD GASES
t t
DUST TO CLEAN GAS
BLAST FURNACES TO 610 ft CHIMNEY

ZINC FUMING FURNACE
1

L
1 f '
GASES AND FUME SLAG LEAD
•

1 'i
WASTE HEAT BOILER HOLDING FURNACE
COOL
72,000 Ib/hr I
MG TUBES TO DUMP
\
BAGHOUSE
960 ORLON BAGS
18 in DIA X 30 ft LONG

CLEA


Y GAS IMPURE ZINC OXIDE
»





DELEADING KILNS







DROSS ING KETTLE
60 tons CAP





DROSS


ERBERATORY
FURNACE
28 ft LONG X 8 ft 4 in WIDE



MATTE
1
TO COPPER

7 ft DIA x 75 ft LONG
1



SPE1SS L
1
DEPT.




t
IAD GASES
L_


1



















L 1 CASTING KETTLE B.F. BAGHOUSE
GASES;* FUME ZINC OXIDE 125 ton EAP 960 WOOD BAGS
BAGHOUSE REFINERY
1
300 ft
              160 ORLON BAGS
              18 in DIA x 30 ft LONG
                   I
                CLEAN GAS
             	I
                                                    8 ton BLOCKS
                                                    99% LEAD
                                                   TO REFINERY
       18 in DIA X 30 ft
                 I  LONG
             CLEAN GAS
           TO CHIMNEYS
HIMNEY
                      Figure 9.
                              Process Flow Diagram for Lead and Zinc
                              Department, ASARCO-E1 Paso Smelter ing Works

-------
                                                                    56
     A process flow diagram of the zinc fuming plant, prepared during
the  inspection, is shown in Figure 10.

     Table 10 shows the operating design data for the zinc fuming plant
operation.  The plant processes approximately 19.6 m. tons (21 tons)/hr
of blast furnace slag and 3.0 m. tons (3.3 tons)/hr of cold slag, producing
approximately 3.8 m. tons (42 tons)/hr of zinc and lead oxide fume.  The
furnace is a bolted water-wall furnace with a capacity of approximately
54 m. tons (60 tons).  The zinc fuming plant handles 10 to 12 charges
per  day.  The total cycle time for the process is approximately 120
minutes.
Process and Emissions Observations

     The zinc fuming furnace was observed throughout its full cycle of
operation during the February 3, 1977 inspection.  Observations were
made as to the process steps conducted, where fugitive emissions occurred,
how the emissions were collected and/or controlled, the effectiveness of
the collection/control systems, and what factors appeared to most in-
fluence the emissions and their control.

     The zinc fuming furnace is charged with 11 m. ton (12 ton) capacity
pots of blast furnace slag which are emptied by crane into a furnace
charging chute and with cold slag which is discharged from a continuous
conveyor into the same charge chute.  Pulverized coal and air are blown
through two rows of tuyeres into the bottom of the furnace.   The crane
transports each pot to a bumper block on the ground adjacent to the
fuming furnace.  The pots are repeatedly banged against the  bumper to
break up skulls, or hardened material, which are formed as the pots
cool.  The pots are then lifted over the charge area hole and emptied
into the furnace.  It takes about 2 to 5 minutes to empty each pot.
Three to five pots are emptied into the furnace for a given  charge.

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                                                                          57
                                     COLD
                                     SLAG
COAL
                                                   VENT FAN
JSLAG 1 1
i
HOLDING
FURNACE
                                                      -4
                                            WASTE
                                            HEAT
                                            BOILER
                                                   SLAG
COPPER
 MATTE
                                       BOILER FANS (2)
                                      INTERMEDIATE FANS (2)
                                       	O	
                                            VENT FAN
                                               ZnO PRODUCT
                                               TO ZINC RECOVERY
                                          PbO PRODUCT
                                          TO LEAD PLANT
      Figure  10.     Process Flow Diagram for Zinc  Fuming Plant,
                      Lead Department, ASARCO-E1  Paso  Smeltering  Works

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                                                               58
                           Table 10

              OPERATING AND DESIGN INFORMATION
              ASARCO - TEXAS ZINC FUMING PLANT12
                          OPERATING

Average cycle times
     Charging/heating
     Fuming
     Tapping

Charges/day

Material flowrates
     Blast furnace slag
     Mine slag
     Coal
     Fume collected

Zinc/lead recovery
     Average lead in input slag
     Average lead in output slag
     Average zinc in input slag
     Average zinc in output slag
Air flowrate, charging
     (minutes)
        25
        80
        15

       10-12

(m.tons/hr)  (tons/hr)
    19.6     21.6
     3.0       3.3
     3.8       4.2
     3.8       4.2

     (% by weight)
         1
         0
       12-16
        0-2
               3
     430 act. m /min.
                           FURNACE
Type                                         water-wall  (bolted)
Capacity                                 59.5 tons    54 m.tons
Dimensions                      6.0 x 2.1  x 10.2 m (19.7 x 6.9 x  33.5
Tuyeres                           26 on north side and 24 on  south
                                  side at variable centers, 14 cm
                                  from bottom, 5 cm diameter
Charging       Hot slag is charged through charge hole on south side
               of furnace approximately 3.7 m from top of furnace.
               Cold slag is charged by conveyor into a charge hole
               chute at the top of the furnace.
                              ft)

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                                                                     59
      The major fume emissions during the charging/heating cycle came
 from the slag pots when they were banged against the bumper block and
 emptied during the charge.  These emissions occurred chiefly near the
 bumper block and at the charge chute.  Some minor leakage of fumes was
 also noted from the furnace walls.  No leakage was observed from the
 waste heat boiler lance doors.

      After all the hot slag had been added to the furnace, the fuming
 stage commences, during which as much zinc as is feasible is removed
 from the molten bath.   The amount of air added to the furnace is main-
 tained fairly constant although the amount of pulverized coal  added may
 be varied to maintain  steam production  within proper limits.  Tertiary
 air, to oxidize the lead and zinc vapor,  is added through the  charge
 opening which is designed to operate at slightly negative pressures.

      During the fuming cycle,  significant  fugitive  emissions were
 observed  from the  charge chute.   These  emissions  consisted of  high-
 opacity,  pulse-like emissions  which  varied  from  about one second to  over
 a  minute  in duration.   The  Company  indicated  that this was due to a
 malfunctioning  soot blower.  When particulate  deposits were  formed on
 the  boiler  tubes,  the  pressure at the charge chute  became positive and,
 as a result,  fumes  were  emitted.  Leaks from furnace walls and waste
 heat boiler lance doors  were very insignificant.

     At the end of  the fuming cycle, the furnace  is tapped through a
 tapping hole and chute.  The chute is hooded and vented to a separate
 baghouse.  During the inspection it took about 10 minutes to tap the
 zinc fuming furnace.  The fugitive emissions from the tapping operation
were relatively minor.   There was some escape of fumes between the  hood
and the furnace.

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                                                                     60
 Fugitive Emissions Controls

     The Company currently has no fugitive emission controls for the
 charging area of the zinc fuming furnace.  However, the Company intends
 to enclose the entire building in which the fuming furnace is located.
 The fugitive emissions, including charging emissions and other fugitive
 emissions from the zinc fuming furnace, will be collected in a venti-
 lation system to be located in the roof of the building.  The collected
 fumes will  be ventilated to a new baghouse for treatment.   The Company
 is designing the system for 16,000 act. m3/min (580,000 acfm) flowrate.
The collection and treatment system is designed to be operational  in
August 1977 and is estimated to cost $8.5 million.

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                                                                    61
                              REFERENCES
1.   Written correspondence, G. M. Baker, Bunker Hill  Company to C.  V.
     Smith, Jr., USEPA-Region X, April  7, 1976.

2.   Atmospheric Emission Evaluation at the Bunker Hill  Company, Kellogg,
     Idaho, Valentine, Fisher and Tomlinson, Seattle,  Wash.  Feb. 7,
     1975.

3.   Bunker Hill Facilities description, Bunker  Hill  Company, 1975  (est.)

4.   Personal communication and facility inspection,  R.  W.  Grosser,  Jr.
     et al., Bunker Hill  Co., and R. J. Gosik, USEPA-NEIC,  Aug.  16-19,
     1976.

5.   Written correspondence with attachments,  R.  W. Crosser,  Jr., Bunker
     Hill Co. to R. J. Gosik, USEPA-NEIC, Oct. 6, 1976.

6.   Written correspondence, R. W. Crosser, Jr.,  Bunker  Hill  Co. to  R.
     J. Gosik, USEPA-NEIC, Jan. 24, 1977.

7.   Personal communication and facility inspection,  R.  W.  Crosser,  Jr.,
     et al., Bunker Hill  Co., and R. J. Gosik, USEPA-NEIC,  March 1-2,
     1977.

8.   Written correspondence with attachments,  T.  H. Coughlin, Bunker
     Hill Co., March 1, 1977.

9.   Source Test Report (p. 1 and 15),  Alsid,  Snowden  and Associates,
     Bellevue, Wash., Aug. 25, 1976.

10.  In-Plant Fugitive Dust Emission Measurements - Bunker  Hill  Lead
     Smelter, G. A. Jutze and L. A. Elfers, PEDCo - Environmental
     Specialists, Inc., Cincinnati, Ohio, Sept.  30, 1975.

11.  Personal communication and facility inspection, S.  R.  Gasser, et
     al., ASARCO Inc., East Helena Plant, and  R.  J. Gosik,  EPA-NEIC,
     July 22, 1976.

12.  Personal communication and facility inspection, D.  P.  Hall  et al.,
     ASARCO Inc., El  Paso Smelting Works, and  R.  J. Gosik,  EPA-NEIC,
     Feb. 3, 1977.

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                                                              62
                        BIBLIOGRAPHY
American Conference of Governmental  Industrial Hygienists, Indus-
trial Ventilation, Ann Arbor,  Michigan,  1974.

Billing, C. E., et. al, Handbook  of  Fabric  Filter Technology, Vol.
II, NTIS PB 200 648.

Cotterill, C. H.  and Cigan,  J.  M.  (ed.), AIME World Symposium on
Mining and Metallurgy of Lead  and Zinc,  New York, N.Y. 1970.

Economic Indicators, Chem.  Eng.,  March  14,  1977.
IGCI, Air Pollution Control  Technology  and  Costs:  Seven Selected
Emission Sources, NTIS PB 245  065, Springfield, Va., December,
1974.

Peters, M. S. and Timmerhaus,  K.  D., Plant  Design and Economics for
Chemical Engineers, New York,  N.Y. 1968.

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          APPENDICES

A  113 Notice of Violation
B  Idaho Air Regulations F and
C  Calculations

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       APPENDIX A
 113 NOTICE OF VIOLATION
BUNKER HILL LEAD SMELTER

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      i:
2
3     '

4

6

6
      ;i

,j     I.               UNITLU SlA'iES  ENVIRONHhinVVL  PROTECTION  AGENCY
       i                                              ""»
fi      i'                                     Ucr.lon  X
       ••                                1200 Six ill AVCIU.C
       j
ji)     |                              ScaLllu,  'rtjsruiujLon

11
         ;:; TiiL :  ifTL:. oir                                  )
12     '                                                      )      No.  X75-OJ-21-113
         f". i'.111  \   Ac I rroccoJinp.                         )
J3     i                                                      )      COMI'LiAiJl'.. 'OiU)k.K
       ;  5 113(..;(L)  [-'.2 I'bCA §  Iti57c-3(a)(]))          ;
14     ,;                                                     >
       ,| Inc  LUM..LI-  Hill Co..pj.iy                          )
15     •                                                      )
                                      respondent.           )
16     .j	!	)

17
         "i1:   ''.'.•  ilnnixui Mill Coi.i,i.-...y
:.-     •;       r.- .  ik'\  29
       ij       K> '. loj^;,  Id.ii o 83S37
IS;     !!       Aim:   Hi:. Jar.ics  llalii1),  Trcuiucnl

               •.•n:.si.anl  to  section  H3(j)(l)  of tliu Cic--.i Air  Act (hoi01.-..iflor

21      !.  rcfcii'O to  as the ACL),  LIIU Rcgion.il Adr..iiusLtatov  now iiiuls  Jfa foilouj,:

 2°                              AOMit.isiiuM'or.'s  rr-iJi" ^
 23     '        L.   Ilic  bunker  Hill c,ui.ipany,  i:cbpom!c:r.,  operates a  le.m  and /.Jnc

 21     '    j.-_. .   .ii.i .1 .M I...LI. j  i  ..laLiO'-  h.iLili  i., .1. I-..LI.  c...:.... .1.1.:- :....«.,oct  in

 25     ;  :ci;uLi  ioa  under  Lnc Clc.in Ail  ACL.
        i!
 26     II        J.   'ilic  Ko'-poi-Ji-iii 's  npoi.iLii.Mi!.  aL  s.iu1  f.iciJity  .iri- sn'ijcv.1 l>i
        i
 '^7     !'  • c-jui •: UMI  I  of  Lho Su.U'  of  Id.ilio't.  Kulc-  lnr  Llio CmiLii.il ••!  ALf

 'JS     i  /c-lJi.1. i.  i-,  i'.u-t  of Li.c  lii.ilio  SLaLo Air iMpli-n-oiUALion  i'lan.   liiaL i\ ,;J-

 2'J   .  ,j l.iuo. u-sLriclh  llic CCIIOIMLIOII ul finjilivc ilust  -i.n.  LC .,ui !•••.,  in ,MIL,
   <     !i
  30    -. .I..TL '..'J  Luason.ibU1 iu-uc.u-.Lirns i.ii.ill b_- t.i' c.i to p! C'vnL  ,' U'ticu l.ito

  31    ;  ii-.'.lii' lion bcciJ'Kinr airborne."
        Ii
  32     •  f.0.1'.;1, I.'X'I. O.:!i' !! - I'.'v.o  1 o.r  f>

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 1


 2


 3


 4


 6


 6


 7


 8


 9


10


11


12


13


14


15


 16


 17


 16


 19


 20


 21


 22


 23


 24


 25


 26


 27


 2?


 29


 30


 31


 32
       3.  H.iscd  on the available in  . nation,  it'is Jecci Minimi  LliaL


  Respondent  h.ib  noi taken nil  leasonablc precautions to pi event. particulatu


  matter from bccor:iny airborne.


       ft.  Respondent wan notified oi its Iai]i.ic to tako such  pn.iMi.it unib

l|
  bj ;\ :.otii.e ol"  Violation directed to it, attention Mr. Jnr.ies  llallcy,


  Prcsidc-.it,  on Ju.ie 17, 1975.


       5.  Sucli violations were observed  to  continue for more  than 30 days


  aft or  t'.-.u  date  of the Notice  of Violation.


       6.  Respondent was afforded and exercised the opportunity to confer


 | concerni.ii; tho  violation required by section  113(a)(i») of  the Cloaii Air


 I Act on August 29, 1975 when Respondent's representatives met  WIL!I


 i Rcjjion.iJ AJinini:.trator Cliffnid V. Snith,  Jr., the AdminL.str.ntor's


 i celct;nti'c, in« tlvo Seattle  Region X offices.

 il
 j1      AIL or a review of the relevant facts,  jpcludii-.g  the seir.n.'.isj.iess .'.•

 l!
 ; r.iirl vii-l.itioMS, "all i;ood  uiith efforts to cui.'ply, .ind  the re<_i>id ol t!ie


      st 29  coiiteronce regardins this i..attcr,  it is hereby
  O;\JJLUI:D  .-1.5 follows:
        I.   No latei I linn  30  il.iys after  each d.iU: spi-cifted ho low, tho


  Respondent sli.ill notify the LPA Regional  Office, in writing, of the


 j] Respondent's achievement or nnnnch levemcnt of the following activities


       !i tho Kospoiiiit-nt  is hereby dirocicd  tJ .•(.liiovc:


             ii.  Si.iterinj1, pri'Cii.s .iro.i  (inc Ludii;,'. nn.i. cntr.ite fc.\:i\
                  (1)  Submit n description and initiate construction  ol


        nr. 'iiul f. ic LI it icb  c.i p.i!) J i- of  pi uv Lil LIU; .idciiu.itc  (.•xli.iui.L c.ip.ihi I i I;.


  j to  j l).ii_,licm:-,o 01 biij'.houucs or other  >ippro|ir Latu control syati-.n  for

  i
  j the soin.-fs 1 is,ted  l-clow by October  Jl,  1973.
                     - :• i-" 7 ol  (<

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3

4

6

6

7

8

9

10

11

12

13

14

15

Iti

IT

IS

19

20

21

22

2J

 il

 25

 2C,

 2V

 2S

 2-J
                      (a)  Return sir'  .  conveyor belt  open transfer point.
                                                                     f .       .
                      (b)  Kcturn sinter  durip to north  (phase  2)  storage


                           tank.

                      (c)  Return sinter  dunp to cast  (pluist-  I)  stor.ii;c


                           Hi nk.


                      (J)  Concentrate  bin conveyor  bait 'nuil.l-n;1. vent


                           fan c.\!iaiibL.

                      (c)  West bedding roon Ian exhaust.


                      (f)  Last beddiny room Ian c.xhaubt.

                      ({•,)  Sinter product line  (open conveyor belt nreus.)


                      (li)   Return sinter, south to  north jnd  wcs:  to east


                            conveyor  belts.


                       (i)   Tr.insfcr  points JiiJ  conveyor  belt., siiviuu  the


                            oiit-£lo\.'  fro.j  tlics pn.isc 1 storage  tdi'.'.v.


                       (j)   IL tins [or  points .liul  ro.ucyor  lu-lti- ^civLiii;  tlic


                            oucllow Iron  the  piia-r.-s 2 storayo tank..


                  (2)   Coiiplctc  consLiuction  o£  •iilJ have  ilucting  aid


         ii-. dubcrilicu  :ibove in Tu]l opciMtioi/ by' M.iroli  31, l'J7».


            b.  jilast K»r».ice Aio.i.

                  (1)  • Select which  ol  the two  alternative  ncd'.ods,  iistc.l


  •jolow t'no 'Junker Hill Company vj.ll use to  contiol fugitive emissions from


•'. L'.u tol'a -ini; sources by Novcribor  1, 1975.

ij                      (a)  IJLa.'-t furittico Ceod  area  (upset).

1                       (li)  1'u'aut iuiii 11.0 ici.-i   v.-i-.ts.
I!
!•                      (c)  JJIast furnace feed   conveyor s>ys.tc-i.i.
 i
 !                 OptJon A.   Adi! onto 1 x i si t J ny  hood Lnj;  anil  ihu-t LP.J; to
ii
I;
I1 capture  c .cuiis  fugitive crimsions  fiou the .-iimrccs  lifted  irn:.i.d uitcl}


 1 .iiiovc .inn  i-onvoy Lhoia  LO .1 new iM^liousc or ot'.u r  fij icirini;  sjij:o..i.
  31

  31.!
 '','.v II'1.1..Mi  Oi"i!.ii - I1-'",1."1  3 of 0

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                           •
                       Option's.  .Modify  u.  i  -place  Llic  existing flue  systcu and




     |  Curry  out necessary  upgrading  Lo  Llic existing  ruin bagliou^e  to r.ainL.i 1:1


     i>

     Ij ailecujLc draft such  that eruptions  and other fugitive ein$s><.iuns>  froi.i


     '!
     ii tlio sources listec immediately above are c.xluu.stcd and ductcc!  through
1
2

Curry
.3 Ij ailec.ua
4 !
i
5
the so
li.l: C,0,
6
i
i
7 ij l.i'non.
i>
8 i
9
10
11



12 !!
13 J!
" i
«• I
16
! taken.
17 i
» '
i
lv


20
21 jj
22
23
24


i
25 1
II
i
i
2" ( tunnel
*J* 1 .mi! cv.-

i
•
29 i •""' •••"
                        (?)   If Option A  ib  chosen, the  following stops  !>:i.ill be








                             (a)  Submit  an  engineering  plan for addiUoiis to




                                  existing iiooding and the installation  of new



                                  control equipment by Dcccrber 31, 1975.




                             (b)  iiegi.i constiuction by  ilay 1, 1976.




                             (c)  Submit  a report of progress by Septea^or 30, j^Tf




                             (d)  Conplutc cunstrnetiun  r.nd opcrtitc uc]ulpiLeiit in




                                  conpliaiicc by Tlarch 31,  1977.



                        (J)   If uption U  is  c-lu'bcu, the  following i,tcp.s  t,h.ill he
                             (a)   Submit  an engineering  plan for wodjJ.'ic.iLions of


                                                                     '
31
      I i-iuiirol
                   or additions to existing conLio1 i ^n'Lpi.ent ur

                                                          i


                   the  instail.ition of  ni.v coniiol ei|uL|... I.-.IL (i!i.it




                   will accor.plish Option U)  by Uccciul^cr Jl, 19."j.




              (b)  Begin construction by Marcli 31, 1976.




              (c)  Submit a report of p:ogress by Scptei.ihor 30, 1975




              (t!)  Subnit :i report of progress by Jlarch 3'L, 1977.




              (e)  Complete LOiistrucLijn >ind in cop'.plitincc by




                   July 31, J977.




         CO   Ucductlon of cnLst-ions from Llic bl^ist furn.icc sin'er




•.i.:iHigli  ii'.sLall.ition of faciliLics to  provide jJjqu.iLo capture




Lr;l of  f.i,;ilivc d;ist  by in->l.:lling noi_essary djctinr,  '.-.ooilin;1.




ijiuitc e\huii-L c.ip.iliility to .1 h.igiuuisc 01 othov .ippLOpri.iLi;




 .:y:.ti-in  sh.il I r«)|Jow Liu- sclmltiU* In-low:
      f..  -li'i.iA-. .: 0!ii)i •{  -  r..i •- /•

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1C


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20
                           (a)  .Begin  con  . accion by October 31, 1975.


                           (b)  Submit engineering evaluation of cncirical


                                suppressant system by March 31, 1976.


                           (c)  Complete construction and  ir. final compliance


                                by October 1, ]97C.


                 c.   Zinc Fiii'.^ni;  Tun-ace.


                      (1)  Provide ai'ecuiate exhaust capability lo a l-.i^hou-.e or


      ba^.liouscs or other .ippropriatc  control system \"or the ::itic Cui.'jni; i.'i—


      r.ace  charging area in accordance with the following schedule:


                           (a)  Submit an engineering plan for the control


                                s.ystur.1 by December 31,  1975.


                           (b)  Issue  purchase orders for  control o(|UJi>3ei-    *


                                January 31,  1976.


                           (c)  Submit a ronort of progress o.i i>e|>tcr.ber 30,


                                1976.


                           (d)  CoupJi'tc construction of and have facilities


                                described Jn I.e. (I)1, above, in  full  operation


                                by  December  31, 1970.


                       (2)  The  /.iiiv. Himinj; fuinaie .••ii.ill be 1.1.1 int.i invd and


       operated in .1  IcaU-Ircc  condition by  Dccei.'.bcr  31, 1975.


     (I          'd.   Silxvr  HuUiri .

     jj
                       (1)  St.ut  construction of  necessary ducting and faciii-

     i1
     Jl ties CO provjdc  adequate cxn.itist  capability  to  a b.ighouse or  bji;'nouucs


     jj or other appropriate  contiol system for  the  silver  rcturt bu^ld.Jag


       roof ve.itri by  Mari.h  3J,  1970.


                       (2)   CoupJoLu conLti-action  of  and have  the ducting and


       iaci.1.11 .•:-. de^cr:.5L-d  an  l.il.(l)  ribovc in fulJ  operation by Dece.ribcr 31,
     'I
29


30


31


3'J
       I            e.   I.e.id Ket iiic-ry.

       !i
         I.. ".rLl.V • .: Oui)LR - I1	  5  <>£  (•

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 1

 2

 3



 5

 6

 7

 8

 9

10

11

12

13

14

15

16

17

16

19

20

21

22

23

24

25

26

27

28



 30

 31

 3.'
                  (1)  Submit an cngi    ing report  specifying necessary

  ducting and facilities  to provide adequate  exhaust capability to a

  b:.£hcuoe or baghouscs or other appropriate;  control system for control

|  rf fugitive emission:, from the lead refinery  roof vcnti. by M.irrh 31,  I97d.

]|                  (2)  Issue purchase orders for control ci|uip.r.cnt by.
!i
i!  i!ay 3i, i*J76.

                  (3)  Ciu.ir.iCiicc construction of  necessaiy ducting and

j  facilities, by Scptonbcr 30, 1976.

                  (O  Submit a report of progress by June 30, 1977.

                  (5)  Submit a report of progress by January 31, 1977.

                  (6)  I'ir.al compliance by July  31,  1970.

       TiiO notification mentioned above shall he made to:
i
|i
            Ms. Nora  MiCoc,  Chief
            Air Ci»-:i'lL.ir.ce Kt.'.luation Section
            U.S. F..i\ i ra.ricntal Protection Aj.er.cy
            It.iil Pi op 513
            1200 S..\tn Avenue
            Seattle,  Wab'uington 98101

       Tlie Respondent'shall  take all reasonable steps, ini'ludin^ pioper

  c.ainten.nicc and  operation  of nil existing  emission control devices,  to

ii control regulated  cnissions during the period covered by this Order.

i.      Nothing in  tnis Order shall prevent  the Adrninistiator from cxercis^n:;
I
 ! those emergency  pcvers hcJJ pursuart  to section 303 of the Clean Air
ll
ji Act [bc of dotoriiininj: ;a) whcti'.cr progress is bi.ing n-.aJVi  as

 | cxpeditiuitsly as practicable; and (b)  the  actual level of emissions

'i during the period  covered  by this Orucr,  the Rcsponucnt shal]:  (1)

S  Maintain buch records, (2) install, use,  anri nuintaiii buch im-.i i to ring
.1
  end s.i..plinf. e<|u_pnent,  (3)  n.il.c sui.li fui ther  rcportsi, and (A) allow such

        1. iv.tn of t!1.^  said  facility and of records peitaining tin.rcto ab
'I the Uc;',ion.il Adr.inistr.itor rn.iy r
:  io-:i': i •••'.!. '.-Knir; -

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         APPENDIX B



IDAHO AIR REGULATIONS F and H

-------
P
     REGULATIONS F and H
                       DEPARTMENT OF




                  HEALTH AND WELFARE

-------
           RUI£S AND REGULA"' "MS FOR THE CCKTROL OF AIR POLLUTICN PI IDAHO

LEGAL AUTHORITY

Tlie Board of Environmental Protection and Health, pursuant to the authority granted
by Chapter 1, Title. 39, Idaho Code, and Chapter 52, Title 67, Idaho Code, did adopt
the following Rules and Regulations for the Control of Air Pollution in Idaho on
October 25, 1972.  Regulations C and Q ware amended by the Board of Environmental
and Conrounity Services on April~ll, 1974 and did determine the effective date to be
April 11, 1974.  Regulation T was adopted and Regulation A attended by the Board of
Environmental and Connunity Services on June 20, 1974, and the Board determined the
effective date to be June 20, 1974.  Regulation U was adopted and Regulation A was
amended by the Board of Health and Welfare on December 5, 1974, and the Board deter-
mined the effective date to be December 5,_1974..A  Regulation S was revised on Janu-
ary ?., 1975, by the Board of HealEh ancflrtblf are , and the Board determined the effective
date to be January 3, 1975.  Regulation U_ was amended on September 18, 1975, and
became effective on October 14, 1975.                                                  2
 A.  GENERAL PROVISIONS ...............................

 B.  AIR POLLUTION EMERGENCY REGULATION .......................
                                                                      ........ 21
 C.  AMBIENT AIR QUALITY STANDARDS  ..................

 D.  REGULATION FOR CONTROL OF OPEN BURNING ............. • .......

 E.  REGULATION FOR CONTROL OF SMOKE OR OTHER VISIBLE EMISSION  ........... 27

 F.  REGULATION FOR CONTROL OF FUGITIVE DUST  ....................

 G.  REGULATION FOR CONTROL OF PARTICULATE EMISSIONS FROM FUEL BURNING EQUIPMENT   .  .  29

 H.   REGULATION FOR CONTROL OF PARTICULATE EMISSIONS FROM INDUSTRIAL PROCESSES   ...  31

                                                                                       33
  I.   REGULATION  FOR  SULFUR CONTENT OF FUEL   ....................
 • J.  REGULATION FOR CONTROL OF FLUORIDE EMISSIONS ................. '

                                                                       ........  35
  K.  REGULATION FOR CONTROL OF ODORS  ................
                                                                                       *r
  L.  REGULATION FOR CONTROL OF INCINERATORS .....................

  M.  REGULATION FOR CONTROL OF MOTOR VEHICLE EMISSIONS  ...............  37

                                                                                       38
  N.  REGULATION FOR CONTROL OF HOT-MIX ASPHALT PLANTS ....... . .........

  0.  REGULATION FOR CONTROL OF KRAFT PULPING MILLS   ................. 39

  P.  REGULATION FOR CONTROL OF WIGWAM BURNERS  ....................

  Q.  REGULATION FOR CONTROL OF RENDERING PLANTS  ................... *5

  R.  REGULATION FOR CONTROL OF SULFUR OXIDES EMISSIONS  FROM SULFURIC ACID PLANTS  . . 45A

   S.  REGULATION FOR CONTROL OF SULFUR OXIDE EMISSIONS FROM COMBINED ZINC/LEAD ^  ^ ^
      SMELTER OPERATIONS ...............................

   T.   REGULATION  FOR AIR POLLUTION SOURCE PERMITS  ..................  63

   U.   STANDARDS OF PERFORMANCE FOR NEW  STATIONARY SOURCES  ..............  66

-------
F.  REGULATION FOR CONTROL OF FUGITIVE DUST

SECTION 1

    Purpose

        The purpose of this regulation is to require that all reasonable
    precautions be taken to prevent the generation of fugitive dust.

SECTION 2
    General Rules

        All reasonable precautions shall be taken to prevent particulate
    matter from becoming airborne.  In determining what is reasonable,
    consideration will be given to factors such as the proximity of dust
    emitting operations to human habitations and/or activities and atmos-
    pheric conditions which might affect the movement of particulate matter.
    Some of the reasonable precautions may include, but are not limited to,
    the following:
    A.  Use, where possible, of water or chemicals for control of dust in
        the demolition of existing buildings or structures, construction
        operations, the grading of roads, or the clearing of land.

    B.  Application of asphalt, oil, water or suitable chemicals to, or
        covering of dirt roads, material stockpiles, and other surfaces
        which can create dusts.

    C.  Installation and use of hoods, fans and fabric filters or equiv-
        alent systems to enclose and vent the handling of duscy materials.
        Adequate containment methods should be employed during sandblast-
        ing or other operations.

    D.  Covering, at all times when in motion, open bodied trucks trans-
        porting materials likely to give rise to airborne dusts.

    E.  Conducting of agricultural practices such as tilling of land,
        application of  fertilizers, etc., in such a manner as to limit
        dust  from becoming airborne.

    F.  Paving of roadways and their maintenance in a clean condition.

    G.  Prompt removal  of earth or other stored material  from streets.

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11.  RHCULATlON FOR CONTROL OK PARTICIPATE EMISSIONS FROM INDUSTRIAL
    PROCESSES

SECTION 1

    PURPOSE
        The purpose of this rep.ulation is to establish participate emission
limits for any operation, process or activity not identified by name and
specifically regulated elsewhere in these rules and regulations, and shall
apply during normal operation.

SECTION 2

    EMISSION LIMITATIONS

        No person shall cause, suffer, allow or permit the emission of  p.ir-
tlculate matter to the atmosphere from any process or process equipment in
excess of the amount shown in Table VII-2 for the process weight rate
allocated to such a process or process equipment.  The rate of emission shall
be the total of all emission points from the source.

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                                 TABU: vn-2
                    ALLOWABLE BATE OF jaassicw BASED CN

-yy) ,un>mfScjaiUl*.T!nrF
?rcce
Lb/tir
••••• ~ 1 1 •" '
100
200
400
600
COO
1,000
1,500
2,000
2,500
3.000
3,500
4,000
5,000
6.000
7.000
8,000
9,000
10.000
12,000

rnyviM«Tffj,'BWff'iJiiiHfrifHon1
to 3 Weight
Rate
Toao/Er
1 1 mi 	 ' "
0.05
0.10
0.20
0.30
0*60
0.50
0.7S
1.00
1.25
1.50
1.75
2.00
2.50
3.00
3.50
4.00
4.50
5.00
6.00
PROCESS WEIGHT RATE*
[gfpf Jjggy rff-'rt"*8'1*"^*13'" •**
Rato of
Eaiooicn
Lb/Iir
0.551
0.877
1.40
1.83
2.22
2.53
3.38
4.10
4.76
5.38
5.96
6.52
7.58
8.56
9.49
10.4
11.2
12.0
13.6

Procoos Weight
Rato
Lb/Er
16,000
18,000
20,000
30,000
40,000
50,000
60,000
70,000
80,000
90,000
100,000
120,000
140.000
160,000
200,000
1,000,000
2,000.000
6,000,000
ftAft.artt^nfr'.fmafmyt^attswt
Tons/Hr
8.00
9.00
10.00
15.00
20.00
25.00
30.00
35.00
40.00
45.00
50.00
60.00
70.00
80.00
100.00
500.00
1,000.00
3,000.00

»«HUJHH[fl.Jll«»g|| |||. IH-I 1 w^imrojnram™i.iim.».«m 	 — 	
*lnterpolation of the data in this table for process weight raj
Ib/hr shall be accomplished by use of the equation E - *.10 P*
in i iinir'ii'fftKHPn*"**mJ**i|g-i--iF[ftym
9£2jglBIMU>SMVM*«^BB*-«>^B*^»H*Mi*^v"1"'
Rate of
Balooton
Lb/Hr
16.5
17.9
19.2
25.2
30.5
35.4
40.0
41.3
42.5
43.6
44.6
46.3
47.8
49.0
51.2
69.0
77.6
92.7
j^iMj«MfPff;MUJfliftffftmW'tff?**!!ai
.63. up to 60,000
'•"7, and inter-
^ _ J *& dK«*^« f* a m ^ ¥
poatlon an  cxrHp
60,000 Ib/hr shall be accompliflhoii by use of the  equation:
E « 55.0
                        - 40,  whar* F " fata  of  etnlosion  In  Ib/hr end
                        P • procooa voioht  roto  In tcsno/hr.

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 APPENDIX C
CALCULATIONS

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PROJECT:  Zinc Fuming Furnace, Bunker Hill Lead Smelter
SUBJECT:  ZnO Baghouse Pressure Drop with an Additional Section
NAME:     R. Gosik  EPA/NEIC
DATE:     3/29/77
Problem:  Determine the decrease in pressure drop for the ZnO baghouse
          if an additional section is added
References:  1.  Handbook of Fabric Filter Technology, Vol.  I Fabric
                 Filter Systems Study, Dec., 1970,  C. E.  Billings et al
             2.  Meeting with Bunker Hill  Co.  and EPA, 3/1/77
Assumptions:  As noted in calculations
Calculations:  1.   Existing baghouse AP ^ 4 in.  WG              [Ref. 2]
               2.   Adding an additional  section  to  the existing 5-section
                   baghouse will  decrease  the  filtering velocity by 5/6
               3.   The pressure drop for the baghouse is  given by the
                   following equation
                         Ap(t)  =  K? .  CiV2t                 [Ref.  1, p.2-160]
                                  *   TTooo
                    where ^ =  resistance  coefficient, C.  =  inlet dust
                               concentration,  v  = filtering  velocity, t  = time
               4.   At  any given time (t) the difference due  to the addition
                   of  another baghouse section is given as
                         APnew  =   V2new   (X Void)2     .7
                         *Pold  "   V2old   " Void2
                    therefore in the case  where  APold = 4  in W.G.
                         APnew  =0.7 x  4  in W.G.   =  2.8 in  W.G.
                    o£ a  reduction  of  up to 1.2  in  W.G. can  be  expected
                      if the baghouse is  expanded  by 1 section

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 PROJECT:  Zinc Fuming Furnace, Bunker Hill Lead Smelter

 SUBJECT:  Hood and ventilation requirements for charging area

 NAME:  R. Gosik   EPA/NEIC

 DATE;  3/28/77

 Problem:  Determine the hood size, and ventilation requirements for
          the following:

               1.   Dual-modified canopy hoods (see attached sketch)
               2.   Dual-side draft hoods
               3.   Single overhead canopy
               4.   Single roof-top collection

 References:  1.  Industrial ventilation, 13th Edition, 1974, American
                 Conference of Governmental  Industrial Hygienists
             2.  Bunker Hill  Co.  drawing S53-731,  Mar. 6, 1962, Fuming
                 Plant Ventilation Fan and Hooding for Fuming Furnace

             3.  Bunker Hill  Co.  drawing S53-732,  Mar. 5, 1962, Fuming
                 Plant Ventilation Fan and Hooding for Fuming Furnace

             4.  Attached sketch  [Fig. 5]

Assumptions:  As  noted in calculations

Calculations:  1.  Dual-modified  canopy hoods

                    a.    Arrangements:  defined  by space restrictions
                         see  attached  sketch  [Fig.  5]

                    b.    Flowrate reg'd (p. 4-18,  ref. 1)

                         Q =  1.4  PDV  where P =  30 ft, D =  8 ft
                                        (dist. from top of  hood to
                                        1/2 the way between the hopper
                                        and pot),  V =  240 fpm (assumption)

                         Q =  1.4  '  30  '  8 ' 240  =  80,000 acfm

               2.   Dual-side draft hoods

                    a.    Dimensions (p.  5-12,  ref.  1)

                              height = 2  x width of 1/2  of  charge
                                        hopper (41)  =  8'
                             width =  4/3 x length  of  charge  hopper  (71) = 9'

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     b.   Flowrate reg'd

               Q = 200 (10 x2 + hood area)

               where 200 is capture velocity which  is
               assumed to be more like  300  fpm,  x =
               distance from top of?pot to  hood  (4') hood
               area = 8 x 9 = 72 ft

               Q = 300 (160 + 72) = 300 (232) =  70,000  acfm

               or for two hoods = 140,000 acfm

3.   Single overhead canopy

     a.   Dimensions:  It is assumed canopy can  be  located at
          sight of present (8'  x 12'  hood).   Per p. 4-18,
          ref.  1 recommended width is dimension^of  charge
          chute + .4 D (D = height above source= 16')
           nd dimension (E-W)  = 7'  + 2x  (.4)  Ib  =  20'
           ide dimension (N-S) = 8'  +0.4(16)  = 15'
End
Side
     b.   Flowrate

          Q = 1.4 PDV where P = 30',  D =  16',  V  =  400  fpm
                         (number assumed)
            =  270,000 acfm

     Single roof-top collection

     a.   Dimensions:  Use existing  roof  and close-up
          existing louvers

     b.   Flowrate

          Q = 1.4 PDV where P = 30',  D =  25',  V  =  400  fpm

          Q = 1.4 (30)(25)400

          Q = 420,000 acfm

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PROJECT:  Zinc Fuming Furnace, Bunker Hill  Lead Smelter

SUBJECT:  Preliminary costs for installing  a new stack fan

NAME:  R. Gosik    EPA/NEIC

DATE:  3/29/77

Problem:  Determine the installed cost and  operating cost for erecting
          a new stack fan for the zinc fuming plant.

References:  1.  Telephone quotation L. Kreeger, American-Standard,  1/17/77
             2.  Correspondence R. W. Crosser, Bunker Hill Co., to
                 R. J. Gosik, USEPA-NEIC, Oct. 6, 1976.
             3.  Plant Design and Economics for Chemical  Engineers,  2nd
                 Ed., Peters and Timmerhaus, 1968.
Assumptions:
1.  Stack fan would be located between cooling tower and baghouse
2.  Stack fan should provide 180,000 acfm at 5 in W.G.
3.  Other assumptions as noted.
4.  Loss in production for down-time not included.
Calculations:  1
     Equipment cost

      per ref. 1           Fan Cost = $45,000
                          Motor cost = $7,000
      Assume additional  ductwork is approximately $2,000

     Installation cost

      per ref. 1   Normal  fan and motor estimated at $8,000
      Assume that added  cost will be required to cut into
      existing balloon flue - 2 men with some crane assistance,
      $50 per hour for 1  week.   $50     40 hr   *
                                 •    X        - 4>£
               3.  Maintenance cost:   Estimate cost (within $500)  as $1,000
                   per year considering continuous usage in a dusty
                   environment.

               4.  Replacement parts:   Estimate cost as $500 per year
                   considering continuous usage in a dusty environment.
               5.  Electricity:   (assume 50% overall  efficiency)
Power required
= 1.573 x 10"4
1
180,000 ft3
mm
5 in W.G.
1
1
.5
leff)
                                                                     =  283 hp

-------
Cost 0 .008$
kwh
= 283 hp
1
7200 kwh
hp/yr
.7 (op. fact.)
1
.008$
kwh
                                                    =   $11,500
6.  Depreciation (10% of installed cost)
    0.10 x $64,000  = $6,500
7.  Taxes and Insurance (3% of installed  cost)
    0.03 x $64,000 = $2,000
8.  Plant overhead (50% of labor and maintenance)
    0.5 x $1,000 = $500

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PROJECT:  Zinc Fuming Furnace,  Bunker  Hill  Lead  Smelter

SUBJECT:  Preliminary costs  for adding a  new ZnO baghouse  section

NAME:  R. Gosik    EPA/NEIC

DATE:  3/29/77

Problem:  Determine the installed cost and  operating  cost  for erecting  a
          new zinc oxide baghouse section

References:  1.  Plant Design and Economics for  Chemical Engineers,  2nd Ed.,
                 Peters and  Timmerhaus, 1968.
             2.  Handbook of Fabric Filter  Technology, Dec.  1970,
                 Vol. I and  II, C.  E.  Billings et al
             3.  Chemical Engineering, Mar. 14,  1977.  Economic Indicators
             4.  Air Pollution Control Technology and Costs:   Seven
                 Selected Emission  Source,  IGC1, Dec.  1974
Assumptions:  1,

              2,
              3,
              4,
1 baghouse section identical  to those ZnO sections
currently being installed.
The baghouse will  handle about 30,000 acfm
Loss in production for down-time not included
Other assumptions  as noted.
Calculations:  1.  Equipment cost
                   a.  Baghouse proper (per ref.  2 assume $5/acfm cost
                         of entire system - 1970, the baghouse proper
                         is 1/3 of that cost)
30,000 acfm

1
3
460 (escalation from 1970)
303
$5 *
acfm
$80,000
                    b.  Auxiliaries
                         Ducting
                    Part.Disposal
                    Instrumentation
                                          °f
                                                      (est. from ref.  2)
                         TOTAL

                    therefore,
                             15%
                             10%
                              5%

                             30%
                ,000 x 0.3 =  $25,000

-------
As a part of installation it will  also be necessary to remove
part of the old ZnO baghouse building and foundation and
extend the building.  Although this cannot be analyzed
accurately without a detail  study, it is estimated as part
of this preliminary study (from ref. 1) that these costs will
be about 25% of the total installed equipment cost:

          $105,000 xO.25 =  $30,000

     2.  Operating labor - no additional labor

     3.  Maintenance (from ref. 2  and 4, it is assumed that
                      total  maintenance costs are $0.5/acfm-yr
                      at 80% op.  factor)

                    30,000 acfm x$0.5  x0.7_     $15,000
                                acfm   0.8
                                  yr.

     4.  Electrical:  There  will be no change in electrical  costs

     5.  Indirect costs

          Depreciation   0.10 x $195,000  =  19,500
     Taxes & Insurance   0.03 x $195,000  =   6,000
        Plant Overhead    0.5 x $15,000  =   7,500

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PROJECT:  Zinc Fuming Furnace,  Bunker Hill  Lead  Smelter

SUBJECT:  Preliminary costs  for erecting  a  new baghouse for charging
          emissions

NAME;  R.  Gosik    EPA/NEIC

DATE:  3/30/77

Problem:  Determine the installed cost and  operating cost for erecting
          a new baghouse to  handle the fuming furnace charging emissions
References:   1
    Plant Design and Economics for Chemical  Engineers,
    2nd Ed., Peters and Timmerhaus, 1968.
2.  Handbook of Fabric Filter Technology,  Dec.  1970, Vol.
    I and II, C. E. Billings, et al
3.  Chemical Engineering, Mar. 14, 1977, Economic Indicators
4.  Air Pollution Control Technology and Costs:  Seven
    Selected Emission Sources, IGC1, Dec.  1974
5.  Telephone conversation, H. Hoons, Flex Kleen, 1/11/77
Assumptions:
     Baghouse can be located nearby to fuming furnace
     Baghouse will handle 80,000 acfm gas and operate at
     99+% particulate removal efficiency
     Loss in production for down time not included in costs
     This system assumed to have a 30% annual operating factor
Calculations;  1.  Equipment cost
                   a.  Baghouse proper (per ref. 2 and 5, assume collector
                         for this application at $2.5/acfm based on new
                         installation)
                    $2.5
                    acfm
                   80,000 acfm  _  $200,000
                    b.  Auxiliaries   (includes ducting, dust removal,
                                       ventilation fan, hoods and
                                       instrumentation, assume at $.65/acfm
                                       per same refs)
                         acfm
                                    so.ooo acfm  *  $50j000

-------
     c.  Installation (assume installation  nearby to
                       the zinc furnace  at  $1.5/acfm)

          $1-50   x  80,000 acfm  *  $120,000
           acfm

2.   Operating labor (from ref. 2)

     Assume 1/6 manyear for operator @ $5/hr

            1/6 x $200  x  52 wk   =  $2,000
                   wk        yr

     Assume additional 20% for supervisor  =  $500

     Benefits @ 25% of labor  =  $500

3.  Maintenance, labor and replacement parts

     (Assume 4 yr service life-acrylic bags, in this  duty)
     Estimate from refs 2 and 4 approximately $.50/acf-yr
     at 80% annual operating factor (incl.  operating  labor)
          80,000 acfm
               1
    .50    0.3.  _
         x 0.8  "
                           acfm

     Subtracting out operating labor

          $15,000 - $2,500  =  $12,500

4.  Electricity  (assume 8 in. W.G.  AP @  80,000 acfm)
                 Assume that this is essentially needed
                 for fan, other electricity req'ts
                 neglected.  Fan overall  efficiency is  50%.
8 in. W.G.
1
80,000 acfm
1
1.573 x ID'4 hp
in. W.G. -acfm
1
U.b
eff.)
7200 kwh
hp yr
0.3
(op. fact.)
1
$0.008
kwh
               =  $3,500
    Indirect costs

     depreciation
   taxes and insurance
     plant overhead
= 0.1 x $370,000  =  37,000
= 0.03 x 370,000  =  11,000
= 0.5 x 15,000    =   7,500

-------
PROJECT:  Zinc Fuming Furnace, Bunker Hill  Lead Smelter

SUBJECT:  Preliminary costs for returning charging fumes to an expanded
          ZnO baghouse

NAME:  R. Gosik  EPA/NEIC

DATE:  3/31/77

Problem:  Determine the installed cost and  operating cost involved in treating
          slag fuming charge fumes in an expanded ZnO baghouse

References:  1.  Calculations and references noted in "Preliminary Costs
                 for Adding a New ZnO Baghouse" Section
             2.  Calculations and references noted, in "Preliminary Costs
                 for Adding a New Stack Fan"
Assumptions:  1.

              2.
              3.
              4.
              5.

Calculations:  1
One additional ZnO baghouse section will  handle the
ZnO charging emissions
An additional stack fan will be necessary
Loss in production from down time not included in costs
Assume 70% annual operating factor
Other assumptions as noted

 Equipment cost

 a.  Baghouse proper (per ref. 1) - $80,000

 b.  Auxiliaries

       Baghouse auxiliaries    $25,000 (ref. 1)
       Fan auxiliaries         $54,000 (ref. 2)

     In addition to the above auxiliaries there will
     be the cost of installing hoods, a ventilation fan
     and ductwork.  These are estimated as follows:

                 hoods     $6,000
                 fan      $25,000
                 ductwork  $4.000
                 TOTAL   ^$120,000

  c.  Installation

            Baghouse & auxiliaries  100,000
            Hoods, fan, ducting      20,000
                                   $120,000

-------
    Operating labor

     Assume additional  operating labor is negligible

    Maintenance - labor, materials and replacement parts
     Baghouse
     Stack
     Ventilating fan
4.  Electricity:

     Stack fan
     Baghouse and
       vent fan
15,000
 1,500
   500
17,000
$11,500

$ 4,500
               TOTAL     $16,000

    Indirect costs

          depreciation
     taxes and insurance
          plant overhead
     Ref. 1
     Ref. 2
     (est.)
     Ref. 1

     (Ref.:  calculations
and references noted in
"Preliminary costs for
erecting a new baghouse
for charging emissions"
+ 2 in. W.G. for added
ductwork)
      = 0.1 x $320,000 = 32,000
      =0.03 x $320,000 =  9,500
      = 0.5 x $ 17,500 =  8,000

-------
PROJECT:  Zinc Fuming Furnace, Bunker Hill  Lead Smelter
SUBJECT:  Preliminary costs for treating charging emissions in
          modified main baghouse
NAME;  R. Gosik

DATE:  3/31/77
      EPA/NEIC
Problem:  Determine the installed cost and operating cost involved in
          treating the slag fuming furnace charging emission
References:
1.

2.

3.
4.
Assumptions:  1
              2.
              3.
Smelter yard map drawing, W10-4, Bunker Hill  Lead
Smelter, dated 7/15/57
Plant Design and Economics for Chemical Engineers, 2nd
Ed., Peters and Timmerhaus, 1968.
Chemical Engineering, Mar. 14, 1977, Economic Indicators
Calculations and references noted in "Preliminary costs for
returning charging fumes to an expanded ZnO baghouses"
Calculations and references noted in "Preliminary costs
for erecting a new baghouse for charging emissions"

 The modified main baghouse will not require further
 modifications to treat zinc fuming furnace charging
 emissions
 Approximately 300'  of 2'<|> ductwork is required
 Other assumptions as noted
Calculations:  1.  Equipment cost
                      Hoods
                      Fan
                      Ducting

                      TOTAL
                                             6,000
                                            25,000
                                             6.000
                                           $37,000

                    Installation = 22,000       (per ref. 4)

               2.  Operating labor costs are assumed to be negligible

               3.  Maintenance - labor, materials and replacement parts

                                   $500         (per ref. 4)
               4.  Electricity:
                    Assume the electricity cost will be the
                    same as calculated in ref. 5 with the
                    addition of approximately another 2 in.
                    W.G. AP requirements for increased ductwork
                    through which gas will be transported
                              3,500 x 1.25

                    Indirect costs
                         Depreciation
                         Taxes and insurance
                         Plant overhead
                                =  $4,500
                                  =  0.1 x 59,000
                                  = 0.03 x 59,000
                                  =  0.5 x 500
                                               =  $6,000
                                               =  $2,000
                                               =  $  500

-------