Document X7R3BYdY5b87ea6OZeNLQ80By
ENGINEERING ASSESSMENT AND PROPOSED COMPLIANCE PLAN FOR
ASARCO'S EL PASO COPPER, LEAD, AND ZINC SMELTER
EL PASO, TEXAS
PREPARED BY: MELVIN E. CASSADY
USDOL/OSHA/HRT MICHAEL O. VARNER
ASARCO MICHAEL WRIGHT
USWA
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ASARCO ELP 0004316
ENGINEERING ASSESSMENT AND PROPOSED COMPLIANCE PLAN FOR ASARCO INCORPORATED - EL PASO, TEXAS
The authors of this report visited Asarco's primary smelter in
El Paso, Texas, on January 10-15, 1982, in order to determine
those additional engineering and work practice controls
feasible at this time for the reduction of occupational
exposure to inorganic arsenic. The El Paso Plant was revisited
on April 11-15, 1983, in order to determine those additional
engineering and work practice controls feasible at this time
for the reduction of occupational exposure to inorganic lead.
The process description is attached to this report as Appendix
A. Based on this assessment and other investigations, we
recommend that Asarco install the controls and meet the other
obligations set forth below; and that the smelter not be cited
during the life of this agreement for violation of the
requirement to install feasible engineering and work practice
controls, as set forth in 29 CFR 1910.1018(g)(1) and 29 CFR
1910.1025(e)(1), if these controls are installed and
obligations met. This tripartite agreement will be deemed to
satisfy the compliance plan requirements of 29 CFR
1910.1018(g)(2) and 29 CFR 1910.1025(e)(3)(ii)[(A-E)] during
the life of this agreement. These recommendations apply only
to those job titles originally identified by the company as
exceeding the permissible exposure limits for inorganic arsenic
or lead. Those-job titles are listed in Appendix B. In
addition, these recommendations are not meant to preclude
citations under other provisions of the inorganic arsenic or
lead standards or other applicable standards; nor are they
meant to affect the right of a worker or worker's
representative to request, or the government to initiate, an
inspection of the smelter; nor are they meant to release the
company or the Union from any obligations contained in existing
or future OSHA settlement agreements, or the collective
bargaining agreement. Furthermore, nothing in this agreement
-shall be interpreted as modifying, limiting or altering
management's right to assign job duties to employees at the El
Paso Plant; nor shall it be construed to add to, diminish or
otherwise modify the rights and obligations under the current
or successor collective
ining agreements, of Asarco, the
USWA and the employees it represents. Any reference to the
"PEL" in this document refers to the arsenic or lead PEL.
I. CONTROLS
A. TRANSPORTATION DEPARTMENT
1. Loco Crane and Loco Crane Helper: The loco crane operators will be studied to determine the source of exposure. If the inside of the cab is over the PEL a significant amount of time, Asarco will install a positive pressure, filtered air system in
ASARCO ELP 0004317
accordance with the priority system outlined in Section III. Asarco will install an automatic water spray system for the outside storage area and ------w-i-11--------apply----- su-f-icient-- moi-stur-e------ to reduce--
reentrainment by wind and movement. All outdoor storage piles of dusty bulk materials containing 1% or more lead or 0.2% or more arsenic will be chemically stabilized. When such piles are broken, they shall be resealed as soon as practicable, but within 24 hours.
2. Moisture Sampler: Asarco will conduct more
intensive sampling and observation in order to identify work practices so as to reduce exposures. The automatic sprinkler system, referred to in
A. 1., should also help reduce exposure to the moisture sampler.
3. Sampler: Asarco's East Helena, Montana, smelter is redesigning a pipe sampler and will be evaluating it to see if exposure levels are reduced. Asarco's El Paso smelter will use the redesigned tool if it proves successful.
4. Buckers, Plateman, and Moisture Sampler: Asarco
will pave the roadway west of the sample mill to
reduce reentrainment potential. Asarco will also
observe the way the buckers perform their tasks and
see if the tasks can be done in another manner to
reduce exposures. The sample mill a'lready has an
extensive ventilation
system.
Sample mill
personnel will continue to properly use the
ventilation system. Asarco will evaluate the use
of transparent plastic strips over the front
portion of some hoods as a means of improving dust
collection. Asarco will also study the feasibility
and effectiveness of further reductions in the air
pressure used for cleaning sample mill equipment
between lots. Asarco will make the following major
modifications in the sample mill:
(a) New, enclosed rod mills, incorporating a
ventilated
clean-out system, will be
installed.
(b) A positive pressure, filtered air system will be installed in the sample mill. The high-grade operations will be relocated in order to take advantage of this system.
(c) The sample mill local exhaust ventilation system, including the make-up air supply, will be revamped.
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ASARCO ELP 0004318
(d) An enclosed v-blender will be installed.
------------------(-e-)--As^r-co-wall-invest-ig-ate--the-feasibility of--an.
isolation arrangement,
incorporating
a
protective shield during equipment clean-up
between sample lots.
5. Laborer: The transportation laborer will be studied to determine the tasks that contribute significantly to his exposure. An administrative work practice program will be developed based on the results of this study.
6. Cat Operator (Outside) and Payloader Operator: Asarco will perform additional sampling inside the cabs. If a cab is over the PEL a significant amount of time, Asarco will install a positive pressure, filtered air system in accordance with the priority system outlined in Section III.
7. Overhead Crane: The-crane operator will be studied to determine the source of exposure. If the crane cab exceeds the PEL a significant amount of time, the existing filtered, pressurized air system will be upgraded.
8. Control Room Operator: The ore unloading control room will be sampled to determine airborne arsenic levels. If the control room is over the PEL a significant amount of time, Asarco will install a positive pressure, filtered air system. The door should remain closed at all times.
9. All Jobs: High-arsenic and lead materials will be
identified before processing so that workers can
take appropriate precautionary measures.
In
particular, workers in the unloading building
basement will be notified by the foreman before
flue dust is dumped. Additionally, sampling will
be conducted in the unloading lunchroom. If the
levels exceed the PEL a significant amount of time,
boot brushes will be installed; and, a positive
pressure filtered air system will be installed in
accordance with the priority system outlined in
Section III.
MILL DEPARTMENT
All Personnel:
To the extent feasible, Asarco will discontinue the use of the crushing mill for lead and arsenic-bearing material. High-arsenic and lead material will be identified before processing so
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ASARCO ELP 0004319
that workers can take appropriate precautionary
______ measures.__ _A_sar_co__ will--per-fox-m --a--s-feudy--of--the-----
crusTTing plant, in order to correlate worker
exposure with the lead and arsenic concentrations
in bulk material, and with plant operations. In
addition, Asarco will investigate the feasibility
and effectiveness of water washdown as an
alternative to compressed air for cleanup between
lots; the use of chemical dust suppressants during
operations; and the installation of a local exhaust
ventilation system.
Asarco will modify work
practices as necessary. In addition, Asarco will
evaluate the feasibility of reducing the air
pressure requirements for air lancing as a clean-up
procedure between different ore runs.
YARD DEPARTMENT
1. Power Sweeper, Motorman, Switchman, Front-End Loader, and Sweeper Operator: Asarco will perform additional sampling inside the cabs. If the inside'
. of a cab is in excess of the PEL a significant amount of time, Asarco will install a positive
pressure, filtered air system in accordance with the priority system outlined in Section III.
2. Heavy Equipment Operator, Forklift, and Backhoe:
Asarco will determine what heavy equipment can
utilize positive pressure, filtered air systems
safely.
Asarco will perform additional air
sampling for all equipment having an enclosed cab.
If the inside of a cab is in excess of the PEL a
significant amount of time, Asarco will install a
positive pressure, filtered air system in
accordance with the priority system outlined in
Section III (where it does not present a safety
hazard). If a piece of equipment does not have an
enclosed cab, and if the operator exceeds the PEL a
significant amount of time while operating the
equipment, Asarco will, where feasible and safe,
install a cab with a positive pressure, filtered
air system in accordance with the priority system
outlined in Section III.
3. Truck Driver: The truck driver will be studied to
determine the source of exposure. If the inside of a cab is over the PEL a significant amount of time, Asarco will install a positive pressure, filtered air system in accordance with the priority system outlined in Section III.
4. Slag Hauler: Asarco will maintain water truck
activity to reduce dusting. Asarco will also perform additional air sampling inside of the cab.
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ASARCO ELP 0004320
If the inside of the cab is in excess of the PEL a significant amount of time, Asarco will install a
---------- ps-i-feive---- pr-e s-s ur-e ,-------f i 1-t-e-r-ed----- a-i-r------- sy-sbem------ in-
accordance with the priority system outlined in Section III.
5. Tool Room Attendant: Asarco will have the yard crew or other personnel clean all equipment before returning it to the tool room attendant. Asarco will also provide proper facilities for such cleaning. If the tool room attendant's exposure remains above the PEL a significant amount of time, Asarco will implement additional administrative procedures to reduce exposure and investigate the feasibility of moving the tool room to a lower
exposure area.
6. Trackboss: Asarco will stress that the trackboss stand upwind during pouring (if possible).
7. Switchman and Motorman: The switchman and motorman
will be studied to determine the source of
exposure. If the inside of the cab or motorman
shed is over the PEL a significant amount of the
time, Asarco will install a positive pressure,
filtered air system in the cab and/or motorman shed
in accordance with the priority system outlined in
Section III.
...
8. Boiler Cleanup: Asarco will investigate the
feasibility and effectiveness of additional
automatic soot blowers. As
much draft as
practicable will be maintained on the reverbs
during boiler cleanup.
9. Laborer: The comments under I.Q.I., Maintenance, are applicable to the laborers. ~
10. General - The controls specified in A.l. should
help reduce exposures to yard personnel. In
addition, Asarco will construct a station and
establish a work practice, under which mobile
equipment will be vacuumed and, if necessary,
washed after each day's use in a regulated or
contaminated area.
Asarco will also assign
. adequate personnel to hydrolaser tasks, in order to
assure that such tasks are done safely. Proper
training will be provided for all employees
assigned to use the hydrolaser.
SINTER PLANT
1. All Personnel: The following controls will be instailed/implemented:
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ASARCO ELP 0004321
a. The hood over the ignition area will be extended;
--------- b';--VentuTs--for-wind boxes-- wrll--be_nrai`Trtanerd--to-
prevent leakage.
Worn venturis will be
replaced immediately;
c. The sinter machine will be maintained under negative pressure;
d. Inspection and access doors will be kept
closed, replaced where necessary, and modified, where appropriate, to open upwards;
e. Asarco will perform sampling in the sinter control room to determine if the existing positive pressure, filtered air system is adequate. If the control room exceeds the PEL a significant amount of time, the existing system will be upgraded.
f. In its training program, Asarco will emphasize the need to use and maintain equipment which affects exposure to arsenic and lead, such as access doors, skirting, ventilation fans, and
. enclosures.
g. Asarco will conduct diily inspections of the sinter plant in order to assure that leaks and sources of spillage are promptly identified and corrected, and that spillage is promptly cleaned up.
h. Asarco will investigate the feasibility of using larger shot in the shot cleaners, .thereby reducing the frequency of hand clean-out.
i. Asarco will investigate the feasibility, effectiveness, and necessity of providing an enclosed, roofed area for excess sinter storage.
2. Payloader: The payloader operator will be studied to determine the source of exposure. If the payloader cab is above the PEL a significant amount of time, Asarco will install a positive pressure, filtered air system in accordance with the priority system outlined in Section III.
3. Attendant: Asarco will perform additional air sampling. If these samples are in excess of the PEL a significant amount of time,_ Asarco will provide the attendant with a clean air station in
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ASARCO ELP 0004322
accordance with the priority system outlined in Section III.
BIAST'TURNACE
..........
1. Scaleman (Car Loader): The present system is
computerized to sense the load level and to activate the local exhaust ventilation. The system is not working properly, resulting in generation of considerable dust at times. Asarco will improve the computerized system or replace it with a manual system operated remotely. After the system is installed, Asarco- will evaluate the control room and employee exposure further to see if additional controls are necessary. If air levels in the control room are above the PEL a significant amount of time, Asarco will install a positive pressure, filtered air system for the control room in accordance with the priority system outlined in Section III. Asarco will increase the air volume for the charge car loading ventilation system, and modify the hooding and/or provide better enclosure. The charge car loading system at Glover will be evaluated for possible application to El Paso. Asarco will investigate the feasibility of automatically wetting the charge cars after filling, in order to minimize emissions during transport and dumping. Asarco will install a system for ventilating the charge car loading operation when the sinter plant is down, unless the PEL can be met without it when the sinter plant is down.
2. Bullgang and Airgunman: Asarco will evaluate the effectiveness of using fogging nozzles where appropriate during repair of the furnaces.
3. Scrap Burner: Asarco will investigate the feasibility of relocating scrap burning to a less contaminated area. Asarco will also ensure that scrap is cleaned before cutting insofar as possible. Where possible, a low volume/high velocity exhaust system will be used.
4. Front-End Loader: Asarco will perform additional sampling inside the cab. If the inside of the cab is in excess of the PEL a significant amount of time, Asarco will install a positive pressure, filtered air system in accordance with the priority system outlined in Section III.
5. Feeder: Asarco will
upgrade the existing
ventilation system on the blast furnace. Asarco
will study the feasibility of operating the charge
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ASARCO ELP 0004323
car remotely. If it can be operated remotely, the
feederman will be placed in a clean air booth and observe feeding visually or by TV camera. If it is
found Ed be feasible, this modification will bb made in accordance with the priority system outlined in Section III. Asarco will utilize a water spray system on the blast furnace top, in order to minimize the generation of dust. Asarco will also require plant personnel to maintain an adequate amount of furnace charge in the shaft to reduce the emissions from the blast furnace. Asarco will improve maintenance and clean up on the charge deck. Asarco will redesign the' thimbles in order to eliminate the interior braces, which warp easily, making clean-up and control more difficult.
6. Furnaceman: The upgraded ventilation system on the blast furnace should greatly improve conditions in
the furnaceman's work area. Asarco will also maintain hoods in proper working order. If these items do not successfully reduce the exposure below the PEL, Asarco will investigate the feasibility of utilizing a clean air station and, if feasible, install such a station in accordance with the priority system outlined in Section III.
7. Conveyorman: The above improvements in the Blast Furnace and Sinter Plant should help reduce the conveyorman exposure. In addition, the conveyorman will be studied to further define sources of exposure and an appropriate control plan will be
implemented.
8. General: Asarco will install a constant air volume
control system for the blast furnace tuyeres. The
East Helena Plant is currently developing a mobile,
ventilated lead pot cover for use with the locos.
If these covers prove effective, they will be
installed at El Paso. The East Helena and Glover
blast furnaces utilize newer step-type designs
which reduce emissions due to charge bridging, and
simplify ventilation problems.
Asarco will
evaluate the feasibility and effectiveness of
replacing the three existing El Paso blast furnaces
with two larger furnaces of the type used at East
Helena and Glover.
DROSS REVERB DEPARTMENT
All Personnel: Asarco will move the switch for the
dross reverb ventilation to the tapping area. Asarco will install an East Helena-type, or similar
ventilation and damper system for the dross reverb charge port and tap holes. Asarco will install hooding
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ASARCO ELP 0004324
and ventilation for the dross kettles. These systems will be tied into the blast furnace ventilation system, ...or._ano.ther_sy.stem--with--s.uff ic.ien.t__ capacity. ___ Asarco. will replace the existing crane cab with a cab" incorporating a positive pressure, filtered air system, designed to eliminate the necessity of reaching out of the enclosure to change directions. If these measures do not reduce exposures to below the PEL, Asarco will prepare a preliminary plan for the total replacement of the existing Dross Reverb Department.
ZINC
ZINC FUMING FURNACE
1. Furnaceman, Furnaceman Helper, Laborer, and Control Room Operator: In conjunction with the converter building control plan, Asarco will evaluate additional ventilation for the zinc fuming furnace, and investigate the effectiveness of ventilating the bumping block. These improvements, if found to be feasible, effective, and necessary, will be made in accordance with the priority system outlined in Section III. Asarco will also evaluate the control room to see if a positive pressure filtered -air system is necessary.
2. Coal Mill Operator: Asarco will resample the coal mill operator and evaluate his source of exposure. A control plan will be prepared based on the evaluation.
3. Fume Loader and Baghouseman: Asarco will make certain that vibrators for chutes are in place and that all leaks and holes in the system are repaired, welded, or otherwise patched. Asarco will also investigate the feasbility of using a central vacuum system for housekeeping in this area and, if it proves feasible, install such a system in accordance with the priority system outlined in Section III. Local exhaust ventilation at transfer points will be upgraded where necessary.
4. Diesel Motor and Switchman: Asarco will resample the cab. If it exceeds the PEL a significant amount of time, Asarco will install a positive pressure, filtered air system in accordance with the priority system outlined in Section III.
5. Kiln Operator and Switchman: Asarco will pave the area east of the kilns and, if necessary, increase water truck and sweeper activity. Asarco will also investigate the possible use of a chemical dust suppressant. Asarco will maintain the kiln exhaust
<r
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ASARCO ELP 0004325
collars in good repair.
-6 --Airgonmam--As ar co-will- evaiu a-te--and7--i-f--necessar-y-,-- improve work practices and ensure that the exhaust ventilation is left on while working inside the furnace.
7. Pulverizer: Asarco will resample this job and if it exceeds the PEL a significant amount of time, Asarco will evaluate the job to determine the controls necessary to reduce exposures, installing such controls in accordance with the priority . system outlined in Section III.
The parties agreed on the above controls as part of the original arsenic evaluation. However, the zinc fuming operation has been discontinued due to the depressed zinc market. If the decision is made to start-up again, the tripartite team will revisit the.plant to further evaluate the operation.
COPPER
ROASTERS
All Personnel: Asarco is investigating the installation of a fan on the bypass to the main stack for use during roaster shut down to prevent smokey conditions at the roaster feed and tripper floors. Asarco will also investigate the feasibility of installing a central vacuum system in the Roaster Department to help cleanup spills at the fire floor and tripper floor. If it is found to be feasible, Asapco will install such a system in accordance with the priority system outlined in Section III. If these controls do not reduce exposures to below the PEL, Asarco will install a clean air station unless the parties agree that a different control would be more effective. Asarco will develop an administrative work practice program for the flue dust puller and will make certain that leaks in the flue dust system are given high priority for repair.
Asarco has implemented, and will continue to debug, a computerized gas flow management system for the sinter plant, roaster and converter flues, and acid plant. This system greatly reduces roaster puffing. Asarco will install secondary hooding on the #4 roaster. If the hooding proves effective, it will be installed on the other roasters. The air inlet to the spray chamber will be redesigned to better distribute collected dust, thereby reducing the frequency of clean-out. Asarco will investigate the feasibility and effectiveness of alternate methods for removing dust from the spray chambers, such as screw or drag conveyors, or water
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ASARCO ELP 0004326
wash. The ventilation system in the calcine loading tunnels will be upgraded, with increased air flow.
- REVERB-DEPARTMENT------------------------------------ ---- ---------------------------- --- -
1. Larry Car: Asarco El Paso personnel will discuss
with Tacoma personnel the feasibility and effectiveness of using level sensors to determine when larry cars are filled. Asarco will maintain the seal between the larry car discharge and the
feeder gun and will study the feasibility of installing local exhaust for the larry cars at the calcine charge hole, installing such exhaust, if feasible, in accordance with the priority system outlined in Section III. Asarco will install removable covers for larry cars, similar to those at Tacoma, unless such covers are infeasible because of space limitation.
2. Skimmer, Tapper, Hot Slagm&n, Charge "Floor Cleanup and Airgunman: Asarco will: (a) replace the sides of the hood for the converter slag return launder, add a flange to the front edge of the hood, and complete a study to determine if an increase of air volume is necessary; (b) use the "Super Sucker" to clean the high line when conditions allow: (c) add additional cover sectionson the matte launder where appropriate; and, (d) install a hooding and ventilation system on the launders for. the slag tap
area and holding furnace.
3. All personnel: Asarco will perform a study of the
larry car operator, in order to determine the
contribution toexposure of calcine
loading,
transporting andcharging. Asarco will install
vibrators on the larry cars in order to eliminate
the use of sledge hammers. Asarco will study the
feasibility and effectiveness of utilizing a vacuum
system for cleaning the reverb charge deck and
arch.
CONVERTER DEPARTMENT
1. Skimmer and Puncher: Asarco will evaluate the feasibility and effectiveness of secondary hoods for the converters. If the secondary hoods are not installed or if they do not reduce exposures below the. PEL, Asarco will enclose the skimmer shacks and install positive pressure, filtered air systems in the shacks and the foreman's office (if they exceed the PEL a significant amount of time). Asarco will also evaluate the feasibility and effectiveness of
a ventilated bumping block.
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ASARCO ELP 0004-327
2. Craneman: Asarco will investigate the feasibility of upgrading the ventilation system in the cabs and redesigning the cabs to allow the cranemen to
________ __observ-e--the-ir--lif ts-wi thout-opening_windows.---------------
3. Laborer and Crane Chaser: Asarco will investigate the feasibility of enclosing and ventilating the receiving ladle for converter boiler dust.
4. General: Asarco will minimize the transport of blast furnace slag through the converter building.
K. ' ANODE DEPARTMENT
All Jobs: After the above changes have been made in the Reverb and Converter Departments, the Anode Department will be reevaluated. If exposures continue to exceed the PEL a significant amount of time, a control plan will be prepared for review by the parties.
L. ACID PLANT
All Jobs: The jobs in the acid plant will be studied to determine sources of exposure. A control plan will be prepared for review by the parties if the PEL is exceeded a significant amount of time.
M. BAGHOUSE DEPARTMENT
1. Tender and Assistant Tender: Asarco will develop a work practice program for the tenders to minimize dust exposure.
2. Payloader Operator: Asarco will replace the present payloader with a Walden loader, having an enclosed positive pressure, filtered air cab.
3. Helper: Asarco will develop and implement a work practice program for the helper. Asarco will also install a movable inspection or access door for the zig-zag blender and will provide local exhaust ventilation for the blender if it is determined that the operation exceeds the PEL a significant amount of time. Asarco will install a clean air station for the zig-zag operator, designing it in such a way that the operation can be controlled, as much as is practicable, from inside. Asarco will put a high priority on zig-zag blender maintenance.
Asarco will investigate the feasibility and effectiveness of alternate methods of dust handling, including pneumatic conveying.
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ASARCO ELP 0004328
4. Hot Cottrell Attendant: Asarco will evaluate the hot cottrell attendant to determine the source of
____exposure. Asarco will also develop a work practice program. Asarco will study the feasibility and effectiveness of installing a central vacuum cleaner for the settled dust accumulations on the top floor of the Cottrell and install such a system, if feasible, in accordance with the priority system outlined in Section III.
5. Water Treatment Operator: Asarco will reevaluate this job to determine the source of exposure. If exposure exceeds the PEL a significant amount of time, Asarco will develop a work practice program.
6. Janitor: Asarco will ensure that the janitor does not dry sweep the changeroom and lunchroom but utilizes sweeping compound or water. Asarco will also make available boot brushes and require their use before entering the lunchroom.
7. Power Sweeper: Asarco will conduct sampling inside the cabs of the power sweepers in use. If the PEL is exceeded a significant amount of time, Asarco will install a positive pressure, filtered air system in accordance with the priority system outlined in Section III. Asarco will also study the feasibility and effectiveness of paving additional areas near the baghouse.
8. Dust Puller: Asarco will investigate methods for conveying flue dust directly from .the baghouse to its destination. An appropriate method(s) will be chosen and implemented.
9. Foreman: Asarco will sample the foreman to determine the source of exposure. The foreman's office will also be sampled. If the office area exceeds the PEL a significant amount of time, Asarco will install a- positive pressure, filtered air system in accordance with the priority system outlined in..Portion III.
10. All Jobs: Asarco will maintain (and if necessary, increase) water truck and sprinkling system and vacuuming activity in the baghouse areas. Because the existing changehouse is inadequate, Asarco will ensure that proper changing and showering facilities are provided for baghouse personnel. These facilities will include a downdraft booth to remove contaminants from work clothes. Asarco will repair leaks in the Sinter Plant ventilation baghouse fan housing as soon as possible after they
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ASARCO ELP 0004-329
occur. A clean, convenient area will be provided
for baghouse personnel to wash their respirators
during the day.___________________ ________
_
N. COTTRELL
1. Operator and Conditioningman: Asarco will evaluate
both job titles to determine the source of
exposure. Asarco willalso develop a work practice
program.
Asarco will study the feasibility and
effectiveness ofinstalling a
central vacuum
cleaning system to clean surfaces before performing
work, and install such a system if feasible in
accordance with the priority system outlined in
Section III.
2. Dust Puller: Asarco will develop a work practice
program for the dust puller. Asarco will also make certain that leaks in the screw conveyor are repaired as soon as possible.
3. Laborer (Pug Mill Operator): Asarco will upgrade
the existing deteriorated ventilation system and hood around the pug mill. Asarco will also test the effectiveness of using fogging nozzles to wet the flue dust. Asarco will install a clean air station for the blender operator in accordance with the priority system outlined in Section III.
4. All ` Jobs: A high-volume vacuum system will be used
when feasible and effective for clean-up under the
cottrell. Cottrell maintenance and sealing will be
upgraded in order to decrease leakage. The pugraill
housing will be upgraded, ventilation improved, and
the pugmill will be exhausted through a new
scrubber or other suitable air cleaning device.
Asarco will evaluate the feasibility and
effectivenss of ' alternate systems for conveying
flue dust from the cottrells to the rail cars, or
other destinations. An appropriate method(s) will
be chosen and
implemented. In the meantime,
transfer point
maintenancewill be improved,
transfer point
ventilationwill be installed,
fogging nozzles will be used if feasible and
effective, and the railroad cars and socks or
chutes into them will be better enclosed. If
visible dust escapes during car loading, a car shed
will be constructed.
0. ANTIMONY PLANT
Asarco will modify the hoods and increase the ventilation on the matte tap, and the antimony furnace
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ASARCO ELP 0004330
generally. Asarco will implement screw or drag conveying, or an alternate system, for the spray-dryer cleanout material. Asarco will enclose the operator's 'control panel in' a'" clean-air station-; i"f iTts" determined that the operator receives a significant exposure during time spent at the panel.
CADMIUM PLANT
1. All Jobs: Asarco will repair and upgrade the existing ventilation system at the packaging station. Asarco will evaluate exposures inside the mobile equipment and breakroom. If levels exceed the PEL a significant amount of time, a positive pressure, filtered air system will be installed in accordance with the priority system outlined in Section III. Asarco will also extend the pavement east of the cadmium plant and increase the housekeeping activities of the sweeper and/or water truck. Asarco will install a downdraft booth for cleaning coveralls. Asarco will also investigate the feasibility of installing a clean air station for the cadmium plant personnel. If feasible, the clean air station will be installed in accordance with the priority system outlined in Section III. In accordance with Section I.T.3., Asarco will monitor and evaluate state-of-the-art development of alternative technology for processing cadmium with a view toward possible replacement of the existing production process with an economically feasible one involving lower worker exposure.
2. Craneman/Payloader and Crane Operator: Asarco will evaluate the exposure of the crane/payloader operator. If the crane cab exceeds the PEL a significant amount of time, Asarco will upgrade the existing Lintern positive pressure, filtered air system or replace it with a larger unit in accordance with the priority system outlined in Section III. Asarco will also evaluate the feasibility and effectiveness of utilizing a payloader with a positive pressure, filtered air cab.
3. Fireman and Assistant Fireman: Asarco will investigate the feasibility of installing a. canopy type hood over the Godfrey roaster (similar to Tacoma design). Asarco will also investigate the feasibility of replacing manual flue dust handling with pneumatic, screw conveyance, or other methods.
MAINTENANCE AND POWER HOUSE
1. Mechanical/Maintenance and Power House Personnel:
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ASARCO ELP 0004331
------ ------
Many of the controls listed above will reduce exposure of maintenance personnel. However, fixed engineering controls are not always practicable for -some--maintenance--jobsy -particularly--those- which-" arise from upset conditions. Therefore, Asarco will stress and enforce good work practices. For example, the welders shall continue to use the portable low-volume/high velocity exhaust systems while working in shops and where feasible, out in the plant. Asarco will make such units available in sufficient quantities to allow their use wherever it is feasible and necessary.
Asarco will evaluate each job in the Maintenance Shops over the PEL and develop an administrative work practice guide for these jobs. Asarco will also designate an area for and provide the proper equipment for decontaminating equipment and material that have been used in the regulated areas of the plant before repairing or welding operations. If exposures are not reduced to or below the PEL, then local exhaust ventilation will be installed where it is feasible and would prove
effective.
ASARCO will ensure that portable shop vacuum cleaners used for arsenic and lead bearing dust are equipped with filters capable of removing lead and arsenic with high efficiency.
2. Truck Driver, Crane Car Operator, Mobile Crane Operator (Grove and Galion): The crane cabs will be studied to determine sources and levels of exposure. If the inside of the cabs are over the PEL a significant amount of time, then Asarco will install a positive pressure, filtered air system in accordance with the priority system outlined in
Section III.
R. SUPERVISORY
Supervisors, foremen, and/or assistant foremen exceed the PEL in several areas. The engineering controls mandated by this agreement which limit the exposure of production workers, such as ventilation systems and clean-air stations, also apply to supervisory
personnel.
S. LABORATORY AND ASSAYING
Asarco will isolate the furnace room. Asarco will
install additional ventilation on specific equipment, where necessary, to reduce exposures to below the PEL.
<r
16
ASARCO ELP 0004-332
T. RESEARCH
1. Positive Pressure Systems - Asarco will evaluate the positive pressure, filterta air systems and components now available "on the market tor crane and vehicle cabs, clean-air stations, control rooms, and other applications. This evaluation will include the equipment's effectiveness, reliability, maintenance requirements, and other characteristics. Based on this evaluation, Asarco will develop a list of performance specifications for each type of unit. Asarco will list the specific available equipment currently meeting these requirements. This list will be updated annually. If no satisfactory unit is available for a particular application, ASARCO will . work with equipment manufacturers or', if necessary, through its own Central Engineering Department or a contractor with the goal of ensuring that such a unit is designed and made available.
2. Exposure Survey - Asarco will study the contribution to employee ' exposure of specific tasks, equipment and processes throughout the plant. Asarco, the USWA and OSHA agree that such a survey could provide more useful information at this time than a continuation of the current quarterly employee exposure sampling. Therefore, Asarco will submit a variance application to OSHA containing a priority list and dates, for source surveys in each plant area, a protocol for the first such survey, and a revised schedule for
employee exposure monitoring.
3. Long Term Engineering and Research - Asarco, the
USWA, and OSHA agree that ultimate compliance with the PEL in many job categories through engineering and work practice controls alone would require long-range technological improvements in production
processes and the capture of air contaminants. Therefore, Asarco will monitor world developments,
continue, and, as necessary, modify its engineering
and research program in these areas.
In
particular, Asarco will give special attention to:
/
a. The handling of dust collected in baghouses,
electrostatic
precipitators,
and
other
air-filtering devices.
b. Local exhaust ventilation systems for ladles, pots and other moving containers. of molten metal, slag, dross, and other materials.
c. Alternate technologies for the production of
if
ASARCO ELP 0004333
lead and its byproducts.
Where appropriate^ this research may include specific
demonstration projects in one or more plants or at Asarco1s Central Research facility. Some such projects are noted in individual plant assessments. Asarco will provide the parties with a list of relevant research reports and of ongoing Asarco projects. This list will be updated on request. The parties will meet on request to review the progress of this research. The USWA and OSHA agree to protect the confidentiality of Asarco research involving trade secret processes or equipment.
II. FORMAT
All investigations undertaken by the company pursuant to
this compliance plan will be the subject of written reports, provided to OSHA and the Union. Supporting studies and documentation will be made available to OSHA and the Union on request. If all the parties agree that a particular control is feasible, it will be installed and used at the earliest feasible time. For some items, deadlines are indicated below. For other, the parties will discuss and set appropriate deadlines based on existing circumstances.
III. COMPLETION DEADLINES
Deadlines for the installation of completion of studies undertaken compliance plan follow.
controls pursuant
and the to this
A. 1
2 3 4
5 6 7
COMPLETION DATES
Positive Pressure, Filtered Air System See * Below
Water Spray System - April 1, 1984 Moisture and stabilization - Immediate October 1, 1983 April 1, 1983 Paving - October 1, 1984 Sample Mill (a) Has been done (b) April 1, 1984 (c) April 1, 1984 (d) Has been done (e) Install, if feasible - October.1, 1984
Remaining Items - April 1, 1983 October 1, 1983 Positive Pressure, Filtered Air System -
See * Below October 1, 1983
18
ASARCO ELP 0004334
8. October 1, 1983 9. Identification of Material - Immediately
Boot Brushes - April 1, 1983 Lunchroom - See * Below
B. Reduction of Air Pressure - April 1, 1983 Identification of Material - Immediately Discontinue use, when feasible - Immediately Study of operations - October 1, 1984 Study of washdown and dust suppression Jan. 1, 1985 Implementation, if feasible - October 1, 1985
- Local Exhaust Ventilation Study and implementation - See * Below
Work Practices - July 1, 1984
C. 1 2 3 4 5
6 7 8 9 10
Positive Pressure, Filtered Air System -
See *'Below Positive Pressure, Filtered Air System -
See * Below Positive Pressure, Filtered Air System -
See * Below Water Truck Activity - Immediately
Remaining - See * Below Cleaning Facilities - April 1, 1983 Administrative - October 1, 1983 Move tool room if necessary - Jan. 1, 1984 Immediately Sampling - October 1, 1983' Installation - See * Below Installation, if feasible - See * Below Maintain draft - Immediately Work Practices - April 1, 1983 Mobile Equipment - July 1, 1984 Hydrolaser - Immediately
D. 1
2 3
(a) October 1, 1983
(b) Immediately (c) Immediately (d) April 1, 1983 (e) October 1, 1983 (f) Immediately
(g) Immediately (h) Feasibility - April 1, 1984
Use, if feasible - July 1, 1984 (i) Study - July 1, 1984
Installation, if feasible, effective and necessary - July 1, 1985
Positive Pressure, Filtered Air System -
See * Below Clean Air Station - See * Below
E. 1. Positive Pressure, Filtered Air System See * Below
1*9
ASARCO ELP 0004-335
Enclosure - July 1, 1984 Air volume, if existing baghouse capacity
is adequate - Jan. 1, 1985 --...... ......... -Ai-r-^voiume7--i-f--exi-sting--capacity-is not------------
adequate - July 1, 1986 Evaluation of Glover system - Jan. 1, 1985 Installation, if feasible, effective, and
necessary - July 1, 1986 Feasibility study of charge car wetting -
April 1, 1984 Installation, if feasible - July 1, 1984 Ventilation when sinter plant is down,
if necessary - Jan. 1, 1988 2. As soon as blast furnace is down for repair 3. Relocation - April 1, 1983
Cleaning - Immediately Low Volume/High Velocity System - Immediately 4. Positive Pressure, Filtered Air System -
See * Below 5. Ventilation System - April 1, 1984
Remote Operation - See * Below Charge Level - Immediately Spray - Immediately Maintenance and clean-up - Immediately Thimbles - July 1, 1985 6. Maintenance - Immediately Clean Air Station - See * Below 7. October 1, 1983 8. Constant Air Volume - First furnace rebuild
subsequent to April 1, 1984 Ventilated pot covers - As soon as
practicable, after a design proves effective and feasible Step furnaces evaluation - Jan. 1, 1988
F. Moving Switch - Immediately Dross Reverb Furnace Ventilation - Jan. 1, 1985 Kettle Ventilation - Jan. 1, 1985 Crane Cab - See * Below Submission of Preliminary Control Plan -
Jan. 1, 1988
G. 1.
See * Below
2. First quarter after start-up
3. Patching - Immediately after start-up
Vacuuming - See * Below
Upgrade Local Exherust - First quarer
after start-up
4. Positive Pressure, Filtered Air System -
See * Below
5. Paving - October 1, 1984
Water Truck Activity - Immediately
Dust Suppressant - April 1, 1984
20
ASARCO ELP 0004336
Kiln Collar - Immediately after start-up 6. Exhaust Ventilation - Immediately
Work Practice - Immediately after start-up ...... ..... -7-.--Evaluate--Puiver-izer--"--See--*~Below------------------
H. Vacuum System - See * Below Clean Air Stations - See * Below Fan or Bypass - April 1, 1983 Work Practice - April 1, 1983 Leaks - Immediately Computerized gas flow system - ongoing #4 Roaster Hooding - April 1, 1984 Hooding on other roasters, if effective July 1, 1985 Air inlet - October 1, 1984 Alternate dust handling methods study July 1, 1985 Implementation of most effective, feasible system - See * Below Tunnel Ventilation - Jan. 1, 1985
I. 1. Level sensors, if feasible - April 1, 1984 Maintain Seal - Immediately Local Exhaust - See * Below Removable Covers, if feasible April 1, 1984
2. (a) Sides and flange - April 1, 1983 Air Volume Study - October 1, 1984
(b) Immediately (c) April 1, 1983 (d) October 1, 1984 3. Larry car study - October 1, 1984 Vibrators - October 1, 1984 Vacuum Study - July 1, 1984 Implementation, if feasible and effective -
Jan. 1, 1985
J. 1. Positive Pressure, Filtered Air System See * Below
2. Upgrade Ventilation System - See * Below 3. April 1, 1984 4. Immediately
K. Control Plan Prepared - See * Below
L. October 1, 1983
M. 1. April 1, 1983 2. Has been ordered and received 3. Work Practice - April 1, 1983 Access Door - April 1, 1983 Local Exhaust Zig-Zag Blender - April 1, 1984 Clean Air Station - July 1, 1984 Maintenance - Immediately
* 21
ASARCO ELP 0004337
Alternate Methods Study - July 1, 1985 Installation of most effective, feasible -
method - See * Below -------- 4-^~ -S ampling--*--Oc-tobe r-1- ,--1-9-83----- ----------------------------------
Work Practice - April 1, 1983 Central Vacuum - See * Below 5. Sampling - October 1, 1983 Work Practice - October 1, 1983 6. Sweeping - Immediately Boot Brushes - April 1, 1983 7. Paving - October 1, 1984 Others - See * Below ' 8. Flue Dust Handling - End of Agreement 9. Positive Pressure, Filtered Air System -
See * Below 10. Water Truck Activity - Immediately
Repair Leaks - Immediately Changeroom - October 1, 1983 Baghouse personnel clean area - Immediately
N. 1. Work Practice - April 1, 1983 Vacuum Cleaning - See * Below
2. Work Practice - April 1, 1983 Leaks - Immediately
3. Ventilation System - April 1, 1983 Fogging Nozzles - April 1, 1983 Clean Air Station - See * Below
4. Vacuum Clean-up - Immediately Cottrell Maintenance - Immediately Pugmill Housing, Ventilation - July i; 1985 Alternate Dust Handling - End of Agreement Transfer Point Maintenance - Immediately Transfer Point Ventilation - July 1, 1985 Fogging Nozzles - July 1, 1984 Car, Socks, Enclosure - July 1, 1984 Shed, if necessary - End of Agreement
O. Hooding and Ventilation - July 1, 1984 Alternate Conveying - Jan. 1, 1985 Clean-air station, if necessary - Jan. 1, 1985
P. 1. Repair and upgrade packaging station April 1, 1983
Pavement - October 1, 1984 Housekeeping - Immediately Downdraft Booth - October 1, 1983 Alternative Technologies - Complete
investigation by end of agreement Remaining - See * Below 2. Positive Pressure, Filtered Air System -
See * Below 3. Canopy Hood - October 1, 1985
Flue dust handling - Installation if feasible. End of Agreement
22
ASARCO ELP 000433S
Q. 1. Portable Local Exhaust - Immediately Work Practices - April 1, 1983 Decontamination - April 1, 1983
-------- ----- Local' Exh'aust"-Apri;l~l7~l'9B4.................................... Portable vacuum cleaners - Immediately
2. Positive Pressure, Filtered Air System See .* Below
S. Isolate Furnace Room - Completed since the visit Ventilation - Jan. 1, 1986
T. 1. Evaluation - July 1, 1984 Design, if necessary - October 1, 1984
2. Application - April 1, 1984 3. Initial list - July 1, 1984
The company has informed the Union and OSHA that, due to the current depressed state of the economy and the uncertainty of future economic conditions in the non-ferrous metals industry, it is unable to anticipate with precision, specific deadlines for the implementation of certain controls described in Section I. Instead, therefore, for those items with the notation "See*Below," Asarco will establish an initial completion schedule utilizing a priority system based on the number of workers exposed, the expected reduction in arsenic levels, and the cost for each control. Controls will be scheduled for the earliest possible completion in accord with this priority system, and all such controls shall be completed by the end of the agreement, unless the parties agree that a particular control is unnecessary, infeasible, or ineffective. The schedule along with the priority determination underlying it will be provided in writing to the Union and to OSHA no later than Jan. 1, 1985. Changes in the schedule with supporting rationale based on the priority considerations set forth above will be listed in the quarterly progress reports discussed in VI. A. below. The parties will meet to discuss the schedule or changes to it if such a meeting is requested by the Union or by OSHA.
GENERAL COMMENTS
A. In the event that unforeseen circumstances render compliance with the deadlines impossible, or if the company believes a particular control is no longer necessary to achieve the PEL, Asarco will promptly notify the parties, who will meet to discuss the situation. If the parties agree, the compliance plan will be modified accordingly. In the event that a particular job title comes into compliance
23*
ASARCO ELP 0004339
with the then existing PEL, additional controls for that job title will not be required.
--B r~ --The- -pat-t-ie s- a r-e-awar-e--fchat-new-o r--d if fex en-fc-con-txol-s-- may be more feasible or more effective than existing controls. For example, such events might include new control devices coming on the market, experience with existing controls, or changes in operating procedures. If Asarco, the USWA, or OSHA believe this may be the case, the parties will meet to discuss the issue. If the parties agree, the compliance plan will be modified accordingly.
C. Asarco will promptly notify the parties in the event
of significant change's in operations, the arsenic
content of materials
received, or any other
circumstances which may significantly change arsenic
or lead exposures in the smelter.
D. In the event that jobs previously believed to be
below the PEL begin to exceed it, the parties may agree to modify the compliance plan to include feasible controls for those jobs.
E. Several items in the agreement require that steps be
taken if the PEL is exceeded a "significant amount
of time." For these items, the PEL will be
considered exceeded if the arithmetic mean of all
samples representative of
current . exposure
conditions exceeds the PEL. However, all three
parties may agree that controls are required, or not
required, if the sampling data and characteristics
of the operation so indicate. These principles
should not serve as a precedent for other
determinations of the necessity of controls.
GENERAL REQUIREMENTS
A. Asarco will continue to use all engineering and work
practice controls currently in existence at the El Paso smelter which limit occupational exposure to arsenic and lead.
B. Asarco will
provide
adequate maintenance,
housekeeping, and training programs in order to
insure that engineering and work practice controls
are as effective as possible.
C. Control devices and other equipment which affects
exposure to arsenic or lead will be inspected and
tested (i) on a regular schedule, which will be
provided to the parties in writing, and (ii) if the
local Union requests and certifies that a condition
warrants such an inspection.
A representative
* 24
ASARCO ELP 0004340
designated by the local union will be permitted to participate in any inspection conducted pursuant to (ii).
D. Control devices and other equipment affecting arsenic and lead exposure in need of repair or cleaning will be repaired or cleaned promptly.
E. Crane and vehicle cabs and clean air stations will be cleaned no less than once each day they are used in regulated areas.
P. During the walk around, it was observed that some ventilation hoods and ducts were deteriorated, rubber conveyor, skirting was removed or not adjusted properly and inspection or access doors were removed or left open. Therefore, by April 1, 1983, Asarco will develop and implement a written maintenance program to ensure that these deficiencies are corrected. Attention to these items would help in reducing exposures; therefore, they will be given a high priority for repair. In addition, Asarco will give special attention to those items identified at the time of the Safety and Health Committee's monthly inspection. However, the existence of a Safety and Health Committee does not' reduce the need * for periodic safety inspections as assigned by management.
G. Asarco will continue to investigate the feasibility and effectiveness of replacing air lancing with vibrators or aerators to unplug chutes and bins, and the use of fogging nozzles where appropriate.
H. If a particular situation"arises in a specific plant area concerning compliance with this Agreement, that the local union in good faith believes warrants an inspection that cannot await the regular monthly safety inspection, such an inspection by the appropriate safety and health representative may be requested and will not be unreasonably denied by the company.
I. During visits to some Asarco plants, the authors noted that certain workers were required to wear respirators in areas which were below the PEL for lead, arsenic, and other air contaminants. This policy will be discontinued. Workers will not be required to wear respirators in areas below applicable PEL'S except during process upsets, control equipment failures, or other conditions likely to raise exposures above the PEL.
J. Newly purchased vehicles and cranes, and other
# 25
ASARCO ELP 0004341
vehicles not specifically mentioned above, which ace
routinely used in regulated areas, will be fitted
with positive pressure, filtered air systems where
'it'TS-ffeasibly e^fS5'fxve'-ahcl_safer
'is- ........
K. The OSHA lead standard requires
.quarterly
ventilation measurements. Each quarter, Asarco will
supply to the Safety and Health Committee, life, list of
the specific hoods, ducts, and equipmentjijphe'icrfeed;
the type of tests; the design parameters jSFanff`'the
results.
PROGRESS REPORTS AND FUTURE VISITATIONS
A. Asarco will provide the parties with qua ;rly air sampling reports and progress reports.
B. Any party may request a tripartite visitation of the
plant to monitor the progress of this compliance plan. Permission for such a visit wilJL not be unreasonably withheld by Asarco. All threfc parties will be given the opportunity to participate.
The authors recommend that this agreement "expire on July 1, 1988. We recommend that the parties revisit the plant before that date, and if possible, renew the agreement by revising the compliance plan as circumstances then warrant.
* 26
ASARCO ELP 0004342
AGREEMENT
-T-he--a-ttached----ENGI-NEER-I-NG--ASSESSMEN-T--AND-P-ROP-OSED--COMP-LTANCE__
PLAN for ASARCO's El Paso Plant, El Paso, Texas, dated
January 30, 1984 was prepared through a cooperative
assessment by Melvin E. Cassady, Occupational Safety and
Health Administration, Michael O.
Varner, ASARCO,
Incorporated, and Michael J. Wright, United Steelworkers of
America, working in cooperation with representatives of
smelter management and USWA local 509. It sets forth
feasible controls and practices to protect the smelter
employees from inorganic arsenic and lead. It incorporates
the relevant controls and practices specified in an earlier
agreement signed November 19, 1982, which was limited to
arsenic.
ASARCO, Incorporated agrees to install the controls, carry out the practices, and meet the other obligations specified in the Engineering Assessment and Proposed Compliance Plan. OSHA agrees the implementation of those controls, practices, and other items meets the requirements to install feasible engineering and work practice controls as set forth in 29 CFR 1910.1018(g)(1) and 29 CFR 1910.1025(e)(1); and the compliance plan requirements of 29 CFR 1910.1018(g)(2) and 29 CFR 1910.1025(e)(3)(ii)(A-E) with respect to the currentjobs listed in the report. This agreement expires on July
1, 1988.
for Occupational Safety & Health
Senior Vice President for Industrial Relations, ASARCO, Incorporated
/,
er'-/' __ Edgar^L. Ball Director, USWA District 37
ASARCO ELP 0004343
APPENDIX A
PTTOC E'S S' 'DE'S'C KIWI ON'
LEAD DEPARTMENT
ORE HANDLING
Except for a very few truck lots, all ore is received in railroad cars of many types.
UNLOADING, BEDDING AND RECLAIMING
Feed constituents for both the lead and copper smelting plants are unloaded and bedded simultaneously.
The unloading building is arranged into two sides, one each
for lead and copper receipts. A standard gauge railroad track passes through the length of each side. The sides are separated by a partition above rail level.. Car pullers bring in strings of up to five railroad cars to the divided lead and copper sides of the Unloading Building. Cars are unloaded one b.y one into the track hopper for bottom dump cars, or clam shell bucket hopper for solid bottom cars.
Each side has an overhead bridge crane equipped with an air conditioned cab.
Conveyor transfer points have water, sprays for suppression.
dust
The two sides of the unloading building are each ventilated through the south building railroad car opening by a jet pulse type baghouse. All copper and lead dust from'this system is delivered to the lead bedding bins.
-Two 35,000 acfm wall mounted air sweep fans introduce fresh outside air to ventilate the clean-up hopper area of each unloading building side.
Housekeeping in the Unloading Building is facilitated by a
water wash down system. Washdown water is pumped to the water treatment plant where solids are recovered as a sludge.
The bedding building includes 14 parallel bedding bins and a
reclaim aisle. Two shuttle conveyors transfer unloaded moistened material from delivery to tripper conveyors. Seven tripper conveyors are mounted between and distributed material to each pair of bins. Six bins (3 pairs} are designated for bedding lead plant receipts, 6 bins (3 pairs) are designated for bedding copper plant receipts, and the
27
ASARCO ELP 0004344
center two bins can each be used for lead or copper bedding. The reclaim aisle contains 11 reclaim hoppers and maneuvering space for_ a Caterpillar 988B front-end loader. Transporting of "be"d mix to the reclaim hoppers is done with" the front-end /loader. Three reclaim hoppers are used for copper bed mix, "five for lead bed mix and the remaining three for lead plant ' recyclable materials.
Continuous ventilation is provided for transfer points of the lead and copper delivery and shuttle conveyors and reclaim belt feeders. Each reclaim hopper is ventilated.
All bedding plant ventilation air passes through a dust dropout box and plenum, then is cleaned in two parallel baghouses and discharged through induced draft fans and 66-foot high steel stacks.
The recovered baghouse dust is slurried and transferred to the water treatment plant for solids recovery.
A water washdown system is employed to control dust on work surfaces. Washdown water is collected at the water treatment plant for solids recovery.
The major source of exposure is material handling.
SINTER PLANT
Raw feed from the bedding building is pulverized by a hammer-type impactor with crushed return sinter, and fed into a double shaft mixer. From the mixer the material is fed into a long pelletizing drum and then, by a system of belts, into the 2 hoppers feeding the sinter machine.
Raw charge is placed on the pallets via the first hopper and ignited by a gas or oil fired burner as tne pallet moves over the downdraft box. The second hopper then places about - 12-inches of raw charge on the top of the ignited layer as the pallets move on to the updraft boxes. All gases are captured in a stainless steel hood and recycled through the windboxes with the high S02 gas being drawn off and routed through a plate and hot wire cottrell before going to the No. 2 Acid Plant.
Sinter from the machine is broken by a claw breaker and crushed by a set of spiked rolls before passing through a set of screening rolls which separates product sinter from return sinter.
Return sinter is crushed by a set of- corrugated rolls and then again by a set of smooth rolls before being conveyed to the elevator to join the raw feed in making up the charge.
28
ASARCO ELP 0004345
A water washdown system is routinely used to remove dust from work surfaces. Washdown system solids are recovered at the water treatment plant.___________
The sources of exposure are hood leakage, open inspection doors and handling of spillage.
BLAST FURNACES/DROSS REVERB
Product sinter and coke are automatically weighed and dumped into a furnace charge car. Direct smelt material is added to the same car by a skip hoist. An electric locomotive moves the charge car under the proper ventilated bins for loading and then to one of two hydraulic elevators which raise the charge car to the feed floor.
There are three thimble top blast furnaces. Two furnaces are in continuous operation with the third in reserve. All molten furnace products are tapped into a settler. All the lead siphons into 15 ton slag lined pots for transfer by rail to the drossing plant. Slag flows from the top of the settler into 150 cubic foot ladles mounted on transfer-cars, for transport to the fuming furnace. Local exhaust ventilation is provided at the furnace tap holes, launders, lead pots and slag ladles.
Lead from the blast furnace is poured into one of three 65 ton cast iron receiving kettles. Soda ash and petroleum coke are added as the kettles are being filled and the dross is removed before it becomes solid and charged directly to an adjacent dross reverberatory furnace. After rough drossing, the lead is bailed out by the overhead crane, using a cast steel five ton bucket and poured into a 130 ton cast iron kettle where a second drossing is done. Final drossing and de-copperizing with sulphur are done in a seco'nd 130 ton kettle. Bullion is cast into 10 ton pigs for shipment to the Omaha refinery.
Dross is smelted in the dross reverberatory furnace. Products of the furnace are soda matte, spaiss and lead bullion. Matte is transferred molten to the copper converters. Speiss is granulated and shipped to the Asarco Hayden Copper Smelter. Lead is tapped directly into the drossing kettles.
Blast furnace and dross reverberatory furnace gases are mixed, cooled by water sprays to 160 degrees Fahrenheit and passed through a 12 chamber baghouse.
The sources of exposure are charging of blast furnaces, tuyere punching, settler hood and launder leakage, movement of slag ladles and lead pots, clean-up, emissions from receiving and refining kettles in the adjacent drossing area, and the general operation of the dross-reverberatory furnace.
4r
29
ASARCO ELP 0004346
COPPER SMELTING
-roasting- --------- --- ---------------------------------------- ---- -...................... - ...............-... -......
Four 7-hearth gas-or oil- fired wedge roastefs are' used for roasting reverberatory charge material called cai:cine. Each roaster is capable of producing 400 tons of calcine per day. Calcine is hauled to the reverb in 7-ton larry cars.
.Roaster gases pass through high velocity flues to a hot gas `fan, then through a spray chamber and a plate and wire cottrell. From here the gases are passed to the 800 ton per day Monsanto double-contact Acid Plant. This acid plant also takes gases from the lead sinter plant.
The sources of exposure are back pressure from the flue system during roaster shutdown, cleanup, overfilling of bins from tripper belt, and general spillage.
SMELTING
The reverberatory furnace is gas- or oil-fired and has a sprung arch. The crucible is entirely jacketed with cast copper. Deep bath smelting is practiced with calcine charging to the reverb. Charging is accomplished through four retractable Wagstaff feed guns.
The molten bath in the reverb furnace is tapped from either side of the furnace into ladles. Matte ladles are conveyed by overhead crane to the copper converters.
Slag is periodically skimmed from the reverb into a gas- or oil-fired settling furnace where the slag is cleaned before transfer to the dump by Kress slag haulers.
Tne off-gases from the reverb pass through a waste heat boiler and then go to a hot gas fan through a spray chamber and a 'plate and wire cottrell to the 828 foot stack.
The sources of exposure are loading calcine into the larry cars, transporting calcine to the reverb furnace, and charging the reverb furnace with tolt'fne. Fugitive emissions from the converter slag return launder, matte tapping, slag skimming, cleanup, and general lack of movement of contaminants out of converter building also contribute to exposure.
CONVERTING
Converting is done in three 13' x 30' Pierce-Smith converters, two of which are normally in operation. The reverberatory matte is charged to the copper converter. In the converter, air is blown into the molten bath to oxidize the sulfur and iron. The product from the converter is blister copper which
30
ASARCO ELP 0004347
is transported by ladle to the Anode Furnaces for further "refining.
Three 60 ton. 90* span overhead cranes service the converters
as well as the anodes, the siag fuming furnace and the reverb
furnace.
Crane cabs have Lintern air conditioning and
filtering systems.
Converter gases pass to a settling tower where coarse dust is collected. Two waste heat boilers are downstream from the converters.
The gases then pass to a hot gas fan, through a spray chamber and a plate and wire cottrell. From the cottrell the gases can go to a 500 ton-per-day double-contact acid plant. There is also the capability to send a portion of the converter gases to the 800 ton-per-day double-contact Acid Plant.
The sources for these exposures are cleanup of converter aisle, leakage from the primary hoods, charging and skimming converters, and general inability of the evacuation system to remove all contaminants from the converter building.
FIRE REFINING OF BLISTER COPPER
31ister copper is fire refined in one of two 160 ton tilting anode furnaces and cast into 720 pound anodes for shipment to
the Asarco copper refinery in Amarillo.
The source of exposure in this area is encroachment of converter building air contaminants.
SLAG FUMING
The fuming furnace is completely water-jacked. Four or five 12-ton ladles of blast furnace slag make up a furnace charge. Blowing time averages 120 minutes. At-tne end of the blow, the slag is tapped into a gas- or oil-fired settling furnace where a matte, carrying 50% of the copper and 85% of the gold and silver in the original slag, separates and is transferred to the converters. From the settling furnace, the spent slag is
taken hot to the dump via Kress slag haulers.
A water-jacketed flue connects the slag fuming furnace with a waste heat boiler. Two fans in parallel at the economizer exit force'the dust-laden gases through two banks of U-tube coolers. Two more fans are located between the U-tubes and the baghouse.
The baghouse contains eight sections, six sections being used for fuming furnace gases and two for fume from the deleading kilns.
Continuously operating screw and drag conveyors carry dust from the boiler, flues, u-tubes and baghouse to the deleading plant.
31
ASARCO ELP 0004348
where 1 1/2% to 3% crushed coal is added before charging to the kilns. In the kilns lead is reduced from 10% in the feed to
about 1-2% in -the- product-,-'which-is-snipped ` to-the'electrolytic' plant at Corpus Christi.
The sources of exposure are charging and tapping the fuming and holding furnaces, cross-contamination from copper processes inside the converter building, baghouse maintenance, leakage from kiln exhaust hoods, unloading East Helena zinc oxide, dust spillage from screw conveyors, and cross-contamination from the Cottrell dust loading area.
ANTIMONY PLANT
Asarco's Antimony Plant was designed to recover pure (99+%) antimony metal from tetrahedrite concentrates. The concentrate is received, weighed, and blended with other components. After blending, the furnace charge is added to a small reverberatory furnace for smelting. Sodium salts are blended in the charge for a water-soluble sodium compound of antimony and sulfur. After smelting is completed, the matte formed in this process is granulated.
The granulated matte then goes to a circuit where the matte is
leached, thickened, and filtered by drum filters.
The
underflow material, residue, is then transported to the copper
circuit. The pregnant leach solution, containing the antimony,
is prepared by electrowinning, cooling, filtering and adding
caustic soda.
The electrolyte then is pumped to the
electrolytic cells for preferentially plating out the antimony
on cathodes. The cathodes can then be further refined and cast
into ingots or sold as cathode metal. This plant has never
been formally released for production purposes. It was not
operating during the Tripartite visit for arsenic.
CADMIUM PLANT
All cellar dust from the blast furnace baghouse that contains greater than 11% cadmium is roasted in a 25* Godfrey roaster. The roaster charge contains approximately 65% flue dust, 15% crushed limerock and 20% coal. The Godfrey roaster generates a fume that is 65% Cd, which is recovered in a baghouse, packaged in special impermeable bags, and shipped to the Globe Plant in Denver. Residue is returned to the Sinter Plant. The source
of exposure is handling of the dust and the fact that trace quantities of arsenic are present in the feed stock.
ACID PLANTS
In December, 1972, Asarco in El Paso started its first acid plant designed to handle S02 from the converters. This plant is a Lurgi-550 TPD double-absorption plant with a design volume of 58,500 SCFM, built by Davy Power Gas.
32
ASARCO ELP 0004349
Hot converter gases are ducted by high velocity flues to a
plate and wire cottrell. Converter gases leave the cottrell at "28`5~'degrees--Fy 'and' enter~the venturi' scrubber'.-- The- "venturi
scrubber cleans particulates from the gases and reduces the gas temperature to 105 degrees F.
Gases leave the venturi and the stream splits before entering ethe packed scrubbers. Here gases are cooled to 75 degrees F and heat is removed from the diluted solution by plate coolers.
The gases then enter the electrostatic precipitators at 75
degrees F, and moisture, as well as remaining particulates, is removed. All the blow down from these three systems is fed back to neutralizer tanks where acidity is neutralized with ammonia and particulates are removed with flocculents before the water is returned to the spray chambers for reuse.
After the precipitators, the gas streams rejoin to one stream before entering the 93% H2S04 drying tower. The drying tower removes any moisture remaining in the gases.
The acid blowers compress the gases for the journey through the remainder of the acid plant.
The gases leave the compressors and must be re-heated by either
heat exhangers or preheater. Once the gases are heated to 750
degrees F, they enter the first two catalyst beds for
conversion.
Next, in the venturi absorber, gases enter the top with a counter-current flow of 98% sulfuric acid that is sprayed into the throat of the entrainment separator, which is a
conventional packed tower. Particulates are removed before gases re-enter the heat exchangers. Gases are re-heated to the conversion temperature of the 3rd and 4th beds and returned to the final absorption tower for further absorption.
The final absorber is. a conventional packed ' tower with a
counter-current flow of 98% sulfuric acid. Gases leave the circulation area and mist pads remove droplets of acid before
the gases ultimately leave the acid plant stack.
In October, 1973, Asarco in El Paso started its second double absorption acid plant. The 750 TPD Monsanto unit has a design volume of 90,000 SCFM. This plant accepts gas from three sources: the lead sintering circuit, copper roasters, and excess converter gases.
The sinter machine gases leave the hot cottrell at 470 degrees F and enter the venturi scrubber. Here particulates are removed and gases are cooled to 140 degrees F for the journey to the acid plant through a F.R.P. duct.
Gases from the roasters leave the cold cottrell at 210 degrees
33
ASARCO ELP 0004350
P and .enter the venturi scrubber. Gases are cooled and particulates are removed and gases leave at 140 degrees P where they join the sinter gases. The combined gas stream from the sinter machine and roasters split to enter the bottom of the packed scrubbers. Gases leave the scrubbers at 90 degrees F and are split again ito enter the mist precipitators. The mist precipitators are of Asarco design for the removal of acid mist and particulates. Gases leave the mist precipitators and form one stream again. At this point any excess converter gas enters from a by-pass duct to join the sinter and roaster gases. Gases then enter the drying tower of the packed tower with 93% sulfuric acid flowing counter-current to the gas stream. The drying tower acid removes any moisture from the gas before entering the compressors. The gases are compressed and move into a mist eliminator for the removal of acid mist before the gas enters the heat exchanger or preheater. Gases are heated for the entry into the 1st bed for conversion. The converter is a 3-pass system with double absorption. The interpass and final absorption towers are conventional packed towers with counter-current flow of 98% sulfuric acid. S03 is absorbed in the towers and the gas passes through mist eliminators for droplet removal prior to dishcarge from the acid plant stack. The plant has a decolorizer facility to treat 93% black sulfuric acid with hydrogen peroxide before storage. This system consists of peroxide storage tanks and a mixing tank where peroxide is added until clarity is obtained before acid is sent to 93% storage tanks. Workers assigned, to the acid plants generally do not have exposures to lead or arsenic above the PEL.
34
ASARCO ELP 0004-351
APPENDIX B
EL EASO...JOB. TITLES . HAVING ARSENIC EXPOSURES ABOVE 10 UG/M3
Transpo rta tion
Loco Crane Operator * Moisture Sampler * Sampler * Bucker * Laborer
Cat Operator * Payloader Operator
Overhead Crane Operator Control Room Operator
Mill
Foreman * Operator * Assistant Operator * Feeder * Mill Tender * Sample Train Tender
Yard
Front End Loader * Power Sweeper Operator
Slag Hauler Operator Heavy Equipment Operator Truck Driver Trackboss * Forklift Operator Tool Room Attendant Back Hoe Operator Boiler Cleanup * Laborer * Sweeper Operator Motorman Switchman
Sinter Plant
Supervisor * Foreman * Payloader Operator
Beltman Laborer Attendant Assistant Attendant*
* 35
ASARCO ELP 0004.352
Blast Furnace
Foreman
* Furnaceman Front End Loader Scaleman/Charge Car Loader
Bull Gang Airgunman Scrap Burner
* Feeder Conveyorman
Dross Reverb
* Furnaceman
* Craneman * Moulder
Zinc Fuming
Foreman * Coal Mill Operator
* Furnaceman * Furnaceman Helper * Fume Loader
Baghouseman
Diesel Motor * Kiln Operator
Control Room Operator
Airgunman
Pulverizer Laborer Switchman
Copper Roasters
Fireman
Repairman Feeder Flue Dust Puller Tripperman Cleanupman
4
Reverb Furnace
Foreman Skimmer Larry Car
Tapper Hot Slagman Charge Floor Cleanup Airgunman
36
ASARCO ELP 0004353
Converters
Foreman. * Skimmer . * Puncher* * Craneman * Crane Chaser * Laborer
Anodes
Moulder Craneman Sampler Airgunman Furnaceman Casting Machine Helper
Acid Plant
Foreman Laborer
Baghouse
* Foreman * He1pe r * Payloader Operator * Power Sweeper * Tender * Dust Puller
Janitor * Hot Cottrell Attendant
H20 Treatment Attendant * Assistant Tender
Cottrell
Operato r * Conditioning Man * Dust Puller * Laborer
Antimony
Foreman Electrowinning Man Filtration Man Furnace Man Furnace Man Helper
Cadmium
* Craneman/Payloader
fj
ASARCO ELP 0004354
* Fireman * Assistant Fireman ng~CTvyrit c~al~7Hal ht'e'nanc S' ....... * Mechanic
Blacksmith Pipefitter Carpenter Painter Mason * Truck Driver * Welder * Apprentice Helper Bo ilermaker Craneman Tool Room Man Hammerman Slurryman Material Man Car Knocker * Crane Car Operator * Flame Cutter Grove Crane Operator * Galion Crane Operator Power House Electrician Instrument Technician Exposures above 100 ug/m3
38
ASARCO ELP 0004355
EL PASO JOB TITLES HAVING LEAD. EXPOSURES.,.ABOVE .50 UG/M3
Transportation Department
* Switchman * Platemman * Loco Crane Helper
Moisture Sampler ** Sampler ** Bucker Laborer ** Cat Operator Payloader Operator Overhead Crane Operator Control Room Operator
Mill
Foreman Opera tor Assistant Operator Feeder ** Mill Tender Sample Train Tender
Yard
* Foreman Front End Loader Power Sweeper Operator ** Slag Hauler Operator Heavy Equipment Operator ** Forklift Operator Back Hoe Operator Boiler Cleanup La bo r e r Sweeper Operator ** Motorman Switchman
* Strawboss * Grader Operator
Sinter Plant
Supervisor Foreman ** Payloader Operator ** Beltman Laborer ** Attendant Assistant Attendant **
a
39
ASARCO ELP 0004356
Blast Furnace
* Supervisor..................................... Foreman' Furnaceman ** Front End Loader Scaleman/Charge Car Loader ** Bull Gang ** Airgunman ** Scrap Burner Feeder ** Conveyorman
Dross Reverb
Furnaceman ** Craneman ** Moulder **
Zinc Fuming
Foreman Coal Mill Operator Furnaceman Furnaceman Helper Fume Loader ** Baghouseman Diesel Motor Kiln Operator ** Airgunman La bo r e r
Copper Roasters
Repairman Flue Dust Puller * Beltman Cleanupman
Reverb Furnace
Foreman Skimmer Larry Car ** Tapper Hot Slagman Charge Floor Cleanup Airgunman
Converters
Foreman Skimmer Puncher
a
40
ASARCO ELP 0004357
Craneman ** Crane Chaser ** Laborer **
Anodes
Craneman Sampler Airgunman Furnaceman
Baqhouse
Foreman Helper ** Payloader Operator ** Power Sweeper ** Tender ** Dust Puller ** Janitor Hot Cottrell Attendant ** Assistant Tender **
Cottrell
Operator Conditioning Man Dust Puller** Laborer **
Cadmium
Craneman/Payloader Fireman Assistant Fireman **
Mechanical/Maintenance
Mechanic Blacksmith Pipefitter Carpenter Painter Mason Helper Boilermaker Slurryman Material Man
Power House
* Power House Helper Electrician
* Electrician Helper **
* 41
ASARCO ELP 0004358