United States
Environmental Protection
Agency
Industrial Environmental Research
Laboratory
Cincinnati OH 45268
EPA 600 2-80-022
January 1980
Research and Development
Evaluation of
Paul Bergsoe & Son
Secondary Lead
Smelter

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                RESEARCH REPORTING SERIES

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

      1.  Environmental Health  Effects Research
      2,  Environmental Protection Technology
      3.  Ecological Research
      4.  Environmental Monitoring
      5.  Socioeconomic Environmental Studies
      6.  Scientific and Technical Assessment Reports (STAR)
      7.  Interagency Energy-Environment Research and Development
      8.  "Special" Reports
      9.  Miscellaneous Reports

This report has been assigned  to the  ENVIRONMENTAL PROTECTION TECH-
NOLOGY series. This series describes research  performed to develop and dem-
onstrate  instrumentation, equipment, and methodology to repair or prevent en-
vironmental degradation from point and non-point sources of pollution. This work
provides the new or improved technology required for the control and treatment
of pollution sources to meet environmental quality standards.
This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia  22161.

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                                                   EPA-600/2-80-022
                                                   January 1980
            EVALUATION OF PAUL BERGSOE & SON
                 SECONDARY LEAD SMELTER
                            by

      Richard T. Coleman, Jr. and Robert Vandervort
                   Radian Corporation
                   Austin, Texas 78766
          Interagency Agreement No. 78-D-X0309
                    Project Officers

                     James A. Gideon
     Division of Physical Science and Engineering
National Institute for Occupational Safety and Health
              Cincinnati, Ohio 45226
                 Alfred B. Craig, Jr
         Metals and Inorganic Chemicals Branch
     Industrial Environmental Research Laboratory
                Cincinnati, Ohio 45268
     INDUSTRIAL ENVIRONMENTAL RESEARCH LABORATORY
          OFFICE OF RESEARCH AND DEVELOPMENT
         U.S. ENVIRONMENTAL PROTECTION AGENCY
                CINCINNATI, OHIO 45268

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                                 DISCLAIMER
     This report has been reviewed by the National Institute for Occupational
Safety and Health (NIOSH) and the U.S. Environmental Protection Agency (EPA),
and approved for publication.  Approval does not signify that the contents
necessarily reflect the views and policies of these agencies nor does mention
of trade names or commercial products constitute endorsement or recommendation
for use.
                                     ii

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                                 FOREWORD
     When energy and material resources are extracted, processed, converted,
and used, the impacts on occupational and environmental health often reauire
that new and increasingly more efficient control methods be used.  The Divi-
sion of Physical Science and Engineering of NIOSH and the Industrial Environr
mental Research Laboratory - Cincinnati (lERL-Ci) of EPA assist in deve-
loping and demonstrating new and improved methodologies that will meet these
needs both efficiently and economically.

     This report presents the findings of an investigation performed to
obtain data concerning fugitive and workroom emissions from secondary lead
smelters.  The results are being used within both NIOSH and EPA as part of
a larger effort to define the potential workplace/environmental impact of
emissions from this industry segment and the need for improved controls.
The findings will also be useful to other agencies and the industry in
dealing with control problems.  Either the Metals and Inorganic Chemicals
Branch of the USEPA or the Division of Physical  Science and Engineering of
NIOSH should be contacted for any additional information desired concerning
this program.
                                             David G. Stephan
                                                 Director
                                Industrial Environmental Research Laboratory
                                                 Cincinnati
                                               Walter Haag
                                                Director
                              Division of Physical Science and Engineering
                                                NIOSH
                                             Cincinnati
                                    111

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                                  ABSTRACT


     The present report presents the results of an interagency study of the SB
battery smelting furnace.  The  study was conducted by  Radian Corp.,  Austin,
Texas, under contract  to the National  Institute  for  Occupational  Safety  and
Health (NIOSH) and the Environmental Protection  Agency (EPA).  The study  was
performed  at  the  Paul Bergsoe  and Son secondary lead smelter  in Glostrup,
Denmark in September,  1978.

     During the test period, the smelter feed materials consisted  of  approx-
imately 12.6 percent(w) polyproplyene  case and 12.6  percent  (w) hard rubber
case whole batteries.  The remainder of the lead  bearing feed materials were
crushed battery plates and  a  small amount  of lead scrap.  The  average pro-
duction rate for the  test period was 70.5 metric tons  of  lead  per day.

     The tests conducted indicated that the  controlled stack emissions were
as  follows:

     . Lead - 0.046  to 0.056 kg/hr

     • Antimony - 0.52 to 0.54  kg/hr

     • Arsenic - 0.0005 to 0.0013 kg/hr

     • Chlorine - 1.6  to 7.1 kg/hr

     . Sulfur - 6.9  to 9.1 kg/hr

     Employee exposures were maintained below 100 jjg/m^  in all  areas of  the
smelter.   This  low exposure is  due  to the  exemplary  engineering and work
practice controls.   Yard  sprinkling,  washdown procedures, and  good  general
housekeeping efforts also helped reduce the levels of lead in and  around  the
workplace.
                                     IV

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                                  CONTENTS
Disclaimer	  ii
Foreword	 iii
Abstract	  iv
Figures	viii
Tables	   x
Conversion Chart	 xii
Acknowledgments	xiii

   1. Introduction	   1

   2. Plant Description	   2
        SB battery smelting furnace	   2
          Furnace operation	   5
          Furnace charging	   6
          Operating parameters	   7
        Flash agglomeration furnace 	   8
        Plant layout	  10

   3. Summary of Results	  14

   4. Source Characterization	  18
        Smelter operating conditions	  18
          Feed characteristics	  18
          Energy consumption	  20
          Production data	  20
          Furnace operation	  22
        High volume air monitoring	  22
        Stack sampling	  24
          Description of sampling locations	  24
          EPA Method  5	;	  26
          Wet electrostatic precipitator (WEP)	  30
          Stack emission factors	  33
        Material flow	  34
          Feed characterization	 .  34
          Product samples	  35
          Elemental partitioning	  36

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                         CONTENTS (Continued)
5. Control Technology Assessment	 37
     Description of equipment and controls	 37
       Receipt of raw materials	 37
       Charge storage and preparation	 37
       SB furnace charging facilities	 39
       SB furnace operating area	 39
       SB furnace integrated ventilation system	 43
       Flue dust handling	 45
     Description of emission sources and potential exposure	 45
       Materials handling emissions	 45
       Charging emissions	 48
       Slag tapping	 48
       Tuyere punching	 49
       Finished metal tapping	 49
       Afterburner slag port	 51
       Agglomeration furnaces	 51
       Baghouse bag replacement	 51
     Engineering control evaluation	 51
       Raw materials handling	 52
       SB furnace integrated ventilation system	 55
       SB furnace charging hood (Hood I)	 58
       Slag tapping hoods (Hoods A,B,C,D)	 58
       Secondary slag tapping hoods (Hoods E and F)	 62
       Finished metal tapping hood (Hood G)	 62
       Finished metal ladle cooling hood (Hood H)	 65
       Agglomeration furnace ladle hood (Hoods J and K)	 68
     Other industrial hygiene considerations	 68
       Employee work schedules	 68
       Personal protective equipment	 68
       Employee hygiene	 69
       Biological monitoring	 69
       Workplace air monitoring	 69
       Noise level measurements	 69
     Control critique	 69

6. Other Process and Controls	 73
     Rotary furnace smelting	 73
       Description of equipment and controls	 73
       Description of emission sources and potential exposures	 78
       Engineering control evaluation	 81
       Other industrial hygiene considerations	 89
       Control critique	 89
                                  vi

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                             CONTENTS  (Continued)
        Pot induction furnace	   91
          Description of equipment and controls	   91
          Description.of emission sources and potential exposures	   91
          Engineering control evaluation	   93
          Control critique	   93

Appendix.  Blood/Lead Data Supplied by Bergs^e Management	   94
                                      vii

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                                   FIGURES

Number                                                                   Page

   1  General process flowsheet for the secondary lead smelter
        industry	  3

   2  Whole battery smelter furnace and flue gas treatment system	  4

   3  Flash agglomeration furnace	  9

   4  Plot plan	 11

   5  Stack cross-section	 25

   6  EPA 5 sampling train	 27

   7  Schematic of the integral WEP sampling train	 31

   8  Wet electrostatic precipitator	 32

   9  Overview of SB furnace building and charge storage and prepa-
        ration building	 38

  10  Furnace charging hood (Hood I)	 40

  11  Key to local exhaust ventilation hoods associated with SB
        furnace and agglomeration furnaces	 41

  12  SB furnace ground level work area, SB furnace building	 42

  13  Overview of exhaust ventilation controls for the tapping of
        slag and finished metal	 44

  14  Agglomeration furnace and ladle hood (Hoods J and K)	 46

  15  Detail of slag tap hole plug and tuyere design	 49

  16  Key to ventilation system test points	 56

  17  Face velocity measurements - furnace charging hood  (Hood I)	 60

  18  Side elevation - slag tapping hood (Hoods A,B,C,D)	 61
                                    viii

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                              FIGURES (Continued)

Number                                                                   Page

  19  Front elevation - slag tapping ladle (Hoods A,B,C,D)	 63

  20  Secondary slag tapping hood (Hoods E and F)	 64

  21  Front elevation of finished metal tapping hood (Hood G)	 66

  22  Finished metal ladle cooling hood (Hood H)	 67

  23  Rotary furnace smelting and charge storage and preparation
        building	 74

  24  Close-up of charge container resting deck, roll-up door,
        and detail of charge container	 76

  25  Rotary furnace charging and tapping controls	 77

  26  Overview of rotary furnace ventilation controls and key
        to ventilation system test points	 84

  27  Finished metal ladle cooling hood	 88

  28  Pot induction furnace hood	 92

                                   PLATES

   1  	 12

   2  	 12

   3  	 13

   4  	 13
                                     ix

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                                  TABLES

Number                                                                   Page

   1  Typical Feed Makeup for SB Smelting Furnace Charge	   6

   2  Approximate Elemental Distribution in Smelter Exit Streams	  15

   3  Stack Emissions Determined Using WEP Train	  16

   4  Typical Charge Materials During the Test Period	  19

   5  Reported Furnace Feed Data for the Test Week	  20

   6  Energy Consumption Data 	  21

   7  Reported Production Data for the Week of September 24, 1978 	  21

   8  Reported Production Data for a 91-Day Campaign 	  21

   9  Operating Parameters Recorded During the Characterization Tests ....  23

  10  Hi-Vol Area Sampling Results 	  24

  11  Traverse Points Measured from the Inside Wall at the Sampling
        Port	  26

  12  EPA Method 5 Results	  28

  13  Lead Particulate Emissions Test Results 	  29

  14  Gaseous Sulfur and Chlorine Emission Test Results 	  29

  15  Total Lead, Arsenic, and Antimony Emission Test Results 	  33

  16  Stack Emission Factors for the SB Battery Smelting Furnace 	  34

  17  Average Feed Material Composition	  35

  18  Product Stream Analyses 	  36

  19  Elemental Partitioning in the SB Smelting Furnace 	  36

  20  Breathing Zone, Lead-in-Air Concentrations Associated with SB
        Furnace Operations 	  53

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                              TABLES (Continued)

Number                                                                   Page

  21  Work Area Lead-in-Air Concentrations Associated with Operation
        of the SB Furnace ................................................. 54

  22  Results of Tests in SB Furnace and Agglomeration Furnaces
        Ventilation Systems ........................ . ............ ... ....... 57

  23  Work Area Arsenic-in-Air Concentrations Associated with Operation
        of SB Furnace ...................... . .............................. 59

  24  Results of Noise Measurements Made in Association with SB Furnace
        Operations ............................. . .......................... 70

  25  Lead and Antimony-in-Air Concentrations Associated with Rotary
        Furnace Operations ................................................ 32
  26  Results of Tests in Rotary Furnace Ventilation System. .... .......... 85

  27  Results of Noise Measurements Made in Association with Rotary
        Furnace Operations ........ . ...... . ................................ 90
                                      xi

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                                           CONVERSION  CHART
To convert from
                                                           To
                                                                                                              Multiply by
British thermal unit (Btu, International Table)
Btu/hour
Btu/second
Btu/ft2-hr-deg F (heat transfer coefficient)
Btu/ft2-hour (heat flux)
Btu/ft-hr-deg F (thermal conductivity)
degree Fahrenheit (°F)
degree Rankine (°R)
foot
foot2
foot/second2
foot2/hour
footz/second
foot3
gallon (U.S. liquid)
horsepower (550 fflbf/s)
inch
inch of mercury(60°F)
inch of water(60°F)
inch2
inch3
kllocalorie
kilogram-force(kgf)
psi
ton (short.2000 Ibm)
watt-hour
joule(j)
watt(W)
watt(W)
j oule/raeter 2-second-kelvin( J/m2 • s -K)
joule/meter2-second(J/m2«s)
j oule/meter-second-kelvln( J /m- a -K)
kelvin(K)
kelvin(K)
meter(m)
meter2(m2)
meter/second 2(m/s 2)
meter 2/aecond(m2/s)
meter 2/second(in2/s)
meter'do3)
ip.eter3(m3)
watt(W)
meter(m)
pascal(Pa)
pascal(Pa)
meterz(m2)
meter3(m3)
joule(J)
newton(N)
pascal(Fa)
kilogram(kg)
joule(J)
1.0550559
2.9307107
1.0550559
5.6782633
3.1545907
1.7307347
             E
             E
             E
             E
             E
             E
*„ • (*„ +• 459
 K.     c
tR - *H/1.8
3.0480000*   E
9.2903040*   E
3.0480000*   E
2.5806400*   E
9.2903040*   E
2.8316847    E
3.7854118    E
7.4569987    E
2.5400000*   E
3.37685      E
2.48843      E
6.4516000*   E
1.6387064*   E
4.1868000*   E
9.8066500*   E
6.8947573    E
9.0718474*   E
3.6000000*   E
+  03
-  01
+  03
+  00
+  00
+  00
.67)/1.8

-  01
-  02
-  01
-  05
-  02
-  02
-  03
+  02
-  02
+  03
+  02
-  04
-  05
+  03
+  00
+  03
+  02
+  03

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                               ACKNOWLEDGMENTS
     The authors would like to thank the Bergs^e management and workers who
were most cooperative during this study.  We would also like to thank Dr.
Thomas Mackey for his help in arranging our meeting in Denmark.

     We would also like to commend the members of the sampling and analytical
team who helped perform this characterization study.  Special thanks to:

          Michael R. Fuchs                    David J. Burton
          Lawrence J. Holcombe                Jay R. Hoover
          C. William Arnold                   Guy M. Crawford
          Robert M. Mann                      Cheryl M. Carter
          Barbara J. Bolding                  David A. Hayes
                                    xiii

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                                 SECTION 1

                                INTRODUCTION
     As part of an interagency effort, the Control Technology Assessment
Branch of NIOSH and the Metals and Inorganic Chemicals Branch of EPA have
performed a characterization of new secondary lead smelting technology.
The processes characterized offer potential solutions to major occupational
and environmental problems associated with secondary crude lead production.
Two major processes were studied:  special battery (SB) smelting and flash
agglomeration of flue dust.  The study was performed at the Paul Bergsoe
and Son smelter in Glostrup, Denmark.

     This study provided both EPA and NIOSH an opportunity to cooperate on
a test program where measurements of both stack and workplace/fugitive
emissions were made.  Fugitive emission rates were not measured directly in
this study.  However, the concept of using workplace lead-in-air levels as
one measure of fugitive emission control effectiveness while recording pro-
cess variables and stack emission data may help in future efforts to pro-
tect both the workers and the environment.  Changes in a process variable
or a stack emission rate may serve as a useful indicator that a particular
agent may present a workplace contamination problem.  This study developed
a coordinated, combined EPA/NIOSH test procedure for process character-
izations. Future test programs may expand on this one to include direct
measurements of fugitive emission rates and fugitive emission control effi-
ciency.

     In Section 2.0, a description of the SB battery smelting furnace is
presented.  Section 3.0 is a summary of the major results of the study.
Section 4.0 presents the detailed results of the source characterization
tests.  Section 5.0 discusses the results of the control technology assess-
ment.  Section 6.0 presents additional results gathered for the control
technology assessment.  The rotary furnaces and electric induction furnace
were evaluated in this part of the study.

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                                 SECTION 2

                             PLANT DESCRIPTION
     Secondary lead smelting involves three major operations:  scrap pre-
treatment, smelting, and refining.  Figure 1 outlines the material flow in
a typical secondary lead smelter and lists the major processes, raw mater-
ials, and products.  SB smelting is an important process because it elim-
inates the battery decasing step when whole batteries comprise a portion of
the  furnace charge.  During the test period, whole batteries comprised 40
percent of the lead-bearing charge.  In addition, since flue dust agglom-
eration is an integral part of the SB smelter, a major part of the smelter
fugitive dust emissions are eliminated.  It is important to note, however,
that SB smelting alone is applicable only for the production of crude lead.
Additional refining processes are required to produce soft lead, lead ox-
ide, or lead alloys.

     SB smelting incorporates both environmental emission control and occu-
pational health features in its design.  Plant layout, raw material storage
and  handling, process and hygiene ventilation, housekeeping, process con-
trol, and flue dust agglomeration are all included in the smelter design.
Also, the SB furnace is operated at conditions producing minimum emissions.
This approach has been implemented by Paul Bergsoe and Son A/S of Glostrup,
Denmark where environmental and occupational health regulations forced
modernization of their lead smelter.

SB BATTERY SMELTING FURNACE

     The SB battery smelting shaft furnace has a rectangular cross section
unlike most cylindrical secondary lead blast furnaces used in the United
States.  The construction is similar to a primary lead blast furnace.  Fig-
ure  2 is a diagram of the furnace and associated gas treatment system.  The
furnace is constructed so as to isolate the charging floor from the bottom
of the furnace.  Additionally, the raw material storage and handling area
is isolated in an enclosed building.  Thus, only the front-end loader oper-
ator charging the furnace works in a "dirty" area.  The front-end loader
does have a filtered air supply.  In addition, the top of the blast furnace
is provided with local exhaust ventilation to minimize fugitive emissions.

     At the bottom of the furnace, local exhaust ventilation is provided
for the four slag taps and the lead ladles.  There are two rows of tuyeres,
one on either side of the furance, designed to use air preheated to 500°C.
The tuyeres have special covers which minimize emissions during punching.

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                                                      5MELTIK6
                                                                                    H£FIH1 KG/CAST I KG
Drosses Residue
Oversize Scrap ~
Residues
on Scrap
Lead Sheathed
Cable and Mire
  High Lead
   Scrap  '
 Oxides, Flue Ousts.
Mixed Scrap (Untreated) '
                                  ±z

Battery
Oecaslng






Rotary /Tube
Sweating
Fuel
Reverberatory
Sweating








1
















































H




"

*\





       Pure Scrap
                                                                                                70-1312-3
           Figure  1.   General process flowsheet  for  the secondary  lead
                          smelting  industry.

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     -LEAD WCU.
                                                                                STREAM

                                                                                 No.
                                                                                     SlM TAP
                                                                                     LfXD *R.i VENT
                                                                                     nnmuef TOP
                                                                                     SANlTUtf VENT
                                                                                 to
                STREAM VAMC
                                                                                       ©+
                                                                                      SEC.
                                                                                      TAf KXMT
                                                                                     process GAS
                                                                                         *
                                                                                      COHR/MCD
                                                                                           VENT
(*See Figure 13 for new

  lead well arrangement)
Figure 2.   Whole  battery smelter  furnace  and flue gas treatment  system.

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     The local exhaust ventilation air and process flue gases are mixed and
all gases pass to four baghouses (at 100-125°C).  The baghouses are a Swedish
design using felted polyester cloth.  The dust is collected on the outside
of the bag and only a mild cleaning air stream is required to dislodge the
dust.  This reportedly gives the bags a longer life.  The baghouses were
designed to operate with three running and one spare.  During the test
period, all four were running.  The air-to-cloth ratio with four baghouses
operating is 34.5 m3/hr/m2 (1.88 ft3/min/ft2).  The effective cloth area is
4720 m2 for four baghouses.  Typical pressure drop across the baghouse is
150 mm (^6 inches) water gauge.

     The collected dust is conveyed in an enclosed screw conveyor system to
one of two small flash agglomeration furnaces.  The flash agglomerator
furnace is oil fired and consumes approximately 7.7 liters of oil per hour.
In this patented process, the dust is melted, reducing its volume by about
80 percent.  The agglomerated dust represents only 2 or 3 percent by weight
of the furnace charge.  This reduction in volume permits an increased
throughput of raw material and increased production per square foot of
furnace cross-section.  Agglomerating the dust also reduces the dust load
circulating in the gas cleaning system because the agglomerated dust is not
entrained from the top of the furnace.

     The smelter area is paved and is wetted and swept periodically.  This
practice minimizes fugitive emissions normally caused by the wind blowing
dry lead dust in the yard.  This wash water is collected, combined with
the acid drainage from cracked batteries stored in the yard, and is finally
treated using a soda ash precipitation process.  The treated effluent is
discharged to the municipal wastewater treatment facility.  The sludge is
withdrawn approximately once every two weeks and is charged back to the
furnace for additional recovery of metals.

     The smelter is serviced by two additional sewer collection systems,
one for rainfall and one for sanitary sewage.  The rainfall collected is
used as washdown water for the smelter yard.  Additional makeup cooling
water is obtained from the municipal water supply.  This water is
softened in an ion exchange unit before use.  Sanitary sewage is discharged
directly to the municipal collection system.

Furnace Operation

     The operation of the SB furnace results in low stack and fugitive lead
emission rates.  The relatively low blast air rate (VJ500 Nm3 air/hr)t and
large furnace cross-sectional area (4.0 m2 at the tuyeres) results in a low
gas velocity.  This combined with the low furnace top temperatures (M.OO°C)
and the absence of loose flue dust in the charge result in a low lead dust
generation rate.  The large furnace cross-section and small production rate
allows the charge material to descend slowly through the furnace shaft.
t Nm  = normal cubic meters, 0°C,  760 mm Hg.

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Thus the charge heats slowly and is not hot enough at the top of the furnace
to generate lead fume.

     This slow heating also prevents the rubber and polypropylene case
material from "burning thru."  Burn-thru could occur when the charge material
is ignited throughout the furnace shaft rather than only in the smelting zone.
This occurs more readily in the SB furnace than in conventional blast furnace
because the rubber or polypropylene case material is present.  It is there-
fore very important to control the furnace temperature both from an operating
and an environmental viewpoint to reduce fuming at the charging port .

Furnace Charging

     In order to help maintain constant temperature in the furnace, the feed
is carefully bedded on the chargeroom floor.  A layer of coke is spread on the
floor first, followed by recycle slag, batteries, plates, scrap iron and other
feed materials.  By doing this, each bucket of material charged to the furnace
contains roughly the right amount of coke.  This practice maintains a homo-
geneous mixture of material in the furnace and helps avoid hot spots.

     Each furnace charge during the test period contained roughly the same
ratio of the materials shown in Table 1.  A front end loader is used to spread
the feed materials on the chargeroom floor.   A large floor scale is used to
weigh the front end loader with a full bucket.   The measurement is fed to the
mini-computer which monitors the smelter operations.   The weight of the empty
front end loader is subtracted and the charge weight is recorded.   A very
accurate measurement of the charge blend is possible using this technique,
typically within 1 to 2 percent of the target on major components (batteries,
plates, etc.) and within 4 to 5 percent on the minor components.

       TABLE 1.  TYPICAL FEED MAKEUP FOR SB SMELTING FURNACE CHARGE
Feed material
  Approximate
weight percent
                                                         Percent of lead
                                                         bearing charge
Whole batteries
-polypropylene case
-hard rubber case
Battery plates
Agglomerated dust } , ,
Drosses j
Return slag
Coke
Scrap iron
FeO (mill scale)
CaC03
Total

12.6
12.6
31.5
:ery mud) 3'2
22.1
5.7
1.9
6.3
0.9
100.0

20.0
20.0
50.0
5.0
5.0





100.0

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Operating Parameters

     At present, the Bergs^e smelter does not have permission to dispose of
the furnace slag in a landfill.  As a result, the furnace is being operated
in a slightly different  fashion  than it would if the slag could be dumped.
At present, the furnace  slag reportedly contains between 1.5 and 3 weight
percent lead.  The samples  gathered during  this study assayed approximately
0.55 weight percent lead.   All of  the slag  is stockpiled and the portion
with a high lead content is recycled to the furnace.  When a dumping permit
is obtained, additional  CaCOa will be added to the charge to maintain the
slag lead content below  2.0 weight percent.

    Adding more CaCOs will  raise the slag melting point and make control of
the SiOa/FeO ratio more  important.  In the  past, accretions  (freezing) at the
tuyere level in the furnace have been a problem.  In some of the early cam-
paigns, large accretions of an iron-containing material had to be removed
from the furnace.  An analysis of  similar accretions taken from the SB fur-
nace constructed at Britannia Lead Co. in Gravesend, England showed that
the following elements were present as expected:  Al, Si, Pb, S, Ca, and Fe.
However, the major crystalline species have not, as yet, been identified.
Bergstfe operators appear to have eliminated the problem by reducing the iron
feed to the furnace.   Blast air oxygen enrichment was also added and report-
edly helped eliminate the problem.   The accretion problem is not expected to
recur when additional CaCOs is added because of the reduction in iron content
of the feed materials.

     Scrap iron and mill scale (FeO) are added to the furnace so that a PbS-
FeS matte forms between  the lead bullion and slag in the furnace.   Most of
the sulfur input is trapped in this matte.   At present,  the matte is being
stored on-site because of its high lead content (^8%).   It must either be
sold to a primary lead smelter or disposed of in a protected landfill.
Recovery of the matte lead content at a secondary lead smelter is not
possible because of the  sulfur.   Sulfur dioxide emission controls would be
required for any furnace processing the matte.  A primary lead smelter,
however,  could combine this material with the normal lead sulfide materials
they process.

     Oxygen enriched air is used in the SB furnace.   Blast air is preheated
to 500°C and then mixed with oxygen prior to entering the furnace.   Preheat-
ing the air reduces the amount of coke required in the furnace and allows
smaller blast air rates  to be used.  As mentioned earlier,  this helps re-
duce dust generation in  the furnace.   Blast air pressure at the tuyeres
ranges from 800 to 1200 mm H20.   The blast air rate is typically between
3200 and 3700 Nm3/hr with between 60 and 115 Nm3/hr of oxygen added.   These
rates correspond to a production rate of between 62 and 74 metric tons Pb
per day.

-------
FLASH AGGLOMERATION FURNACE

     The flue dust generated by smelting automobile batteries and battery
manufacture scrap melts at approximately 400 to 900°C  (750 to 1650°F).
This low melting point makes flash agglomeration of flue dust possible.
Dusts with higher melting points cannot be agglomerated using this  tech-
nique without causing the low melting materials to volatilize.  A special
furnace was designed to take advantage of this property so that dust  hand-
ling could be completely avoided.

     At most secondary lead smelters, it is common practice to return flue
dust directly to either the blast furnace or a reverberatory furnace.  A
considerable amount of this dust is entrained in the furnace flue gas sys-
tem.  Agglomerating the flue dust prevents entrainment, thus reducing the
load on the baghouse and improving its performance.

     The Bergsoe smelter has two agglomeration furnaces serving the four SB
furnace baghouses.  Figure 3 is a diagram of a flash agglomeration  furnace.
The agglomeration furnace is fed directly from the baghouse dust hoppers
via screw conveyor.  The dust drops onto the furnace hearth where it  melts
almost instantaneously upon contact with an impinging  flame.  The liquid
runs down the sloping hearth, through a permanently open taphole and  into  a
cast iron vessel where it solidifies.  This completely eliminates handling
of the dust, the associated occupational hazard, and fugitive emissions
from flue dust  storage piles provided that the agglomeratged dust is  stored
indoors.

     Tipping the solidified contents of the cast iron vessels onto  the
floor  is usually sufficient to break the material into lumps suitable for
recharging to the blast furnace.  It is simply  mixed with coke and flux
and loaded into the top of the blast furnace along with other charge  mater-
ials .

     Since the  agglomeration furnace produces a product which is both great-
ly reduced in volume and which does not create a significant recycle  of  re-
entrained dust  from the furnace to the baghouse, additional material  can be
charged to the  furnace, thus increasing the smelting rate.  This is one
economic justification for the agglomeration furnace.

     A contamination of the flue dust also takes place.  Lead chloride
forms as the polyvinyl chloride battery plate separators are smelted.  Lead
chloride is more volatile than other oxide materials in the furnace.   Re-
circulating the flue dust causes lead chloride to preferentially volatilize
in the furnace, further, increasing the chlorine content of the flue  dust.
Flue dust which has accumulated a large percentage of  chlorine can  be ei-
ther leached to remove the chlorine, or used as a fluxing agent in  another
part of the smelter.

-------
           PROCESS VENT
BAGHOUSE-
DUST HOPPER.
BUfLNER.
                       SCREW
                       CONVEYOR.
                          rf&f&s£&^^
                                          AGGLOMERATION
                                            FUKA/ACE
                                            SLOPED HEARTH
                                            MOLTEN DUST
                      COOLING /T&A NSPORTA 77CW
                Figure 3.  Flash agglomeration furnace.
                                                            0225281

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PLANT LAYOUT

     A plot plan of the new Bergs^e smelter is shown in Figure 4.  The old
lead smelter, the lead refinery, the small cast iron department, the copper
department, and the other small smelting operations are located between 100
and 400 meters southwest of the new smelter.  The old smelter was built in
the 1930's.  Construction on the new smelter began in 1973 and the initial
startup occurred in 1975.

     The SB furnace is located in the building labelled #1 on Figure 4.  As
mentioned earlier, the furnace building isolates the top of the furnace where
the charging takes place from the work area on.the first floor.  Plate 1 shows
the front end loader charging material to the furnace top.  The large hood
over the charge area captures emissions escaping the furnace top.  Plate 2
is a view of the outside of the building looking east.  The SB furnace build-
ing is on the left.  The afterburner chamber can be seen between the building
and the four large baghouses.  The two small agglomeration furnaces are located
in front of the baghouses.  Plate 3 shows the tapping area on the first floor
of the SB furnace building.  Plate 4 is a view of the two agglomeration furnaces.

     As shown in Figure 4, the SB furnace and the two short rotary furnaces
located in Building #3 both discharge to a common stack.  The rotary furnaces
were not operating during the SB furnace test period.

     Raw materials are stored in concrete bins in Building #2 in Figure 4.
Building #2 also contains the charge bedding area.  Building #2 is not large
enough to contain all of the raw materials because of the irregular receipt
of scrap material.  As a result, several large piles of plates, unbroken
batteries, and clean lead scrap are stored to the west of Buildings #1 and #2.

     The small sodium carbonate water treatment plant is located between the
old and new smelters to the south of Building #1.   As can be seen in Figure 4,
the smelter fenceline is 200 meters east southeast from the SB furnace build-
ing.   This is the closest point from smelter to fenceline. The
prevailing winds are from either the west or west northwest.
                                      10

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Figure 4.  Plot plan

-------
  PLATE 1.  Front end loader delivering charge
            to top of SB Furnace.
PLATE 2.   View of smelter building and baghouse.
                      L2

-------
      PLATE 3.   Slag tapping area,
PLATE 4.   View of agglomeration furnace,
                    13

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                                 SECTION 3

                            SUMMARY OF RESULTS
     In this section,  the results of the NIOSH and EPA source characteriza-
tion studies are summarized.   The purpose of the testing performed for this
program was to characterize the operation of and emissions from the com-
bined SB smelting and flue dust agglomeration furnaces.  The source char-
acterization included:  1) an analysis of the smelter feed materials, 2) a
description of the furnace operation, 3) a determination of the flows of
lead, antimony, arsenic, chlorine, and sulfur, 4) measurement of stack
emissions, 5) calculation of an emission factor, 6) measurement of lead-in-
air levels in the smelter yard, 7) workplace and personal monitoring, 8)
evaluation of ventilation and other employee exposure control systems, and
9) observation and evaluation of work practices and personal protective
equipemnt.

     The major results are:

     •   The smelter feed consisted of the followng materials:

         Whole Batteries
           -polypropylene case
           -hard rubber case
         Battery Plates
         Agglomerated Dustlor battery mud]
         Drosses         -*
         Return Slag
         Coke
         Scrap Iron
         Mill Scale (FeO)
         CaC03
              Total

         The total input materials contained an average of 79 metric tons
         lead,  1.5 metric tons antimony, 29 kilograms arsenic, 0.1 metric
         tons chlorine,  and 2.6 metric tons sulfur per day.

     •    During the test period, these five elements were distributed in
         the smelter output materials as shown in Table 2:
                                    14

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TABLE 2.  APPROXIMATE ELEMENTAL DISTRIBUTION IN SMELTER EXIT STREAMS
Percent of total incoming flow
Output stream
Lead bullion
Lead stone (matte)
Stack Gas
Total
(Estimated accuracy of
Pb
87.7
0.90
0.0025
89
elemental
Sb
98.5
11.2
0.84
110
flow rates
As
10.4
75.7
0.07
86
is +20%.)
Cl
12.8
36.8
75.8
125

S
0.14
98.0
7.2
105

  •    The chlorine content of the agglomerated flue dust averaged
      25 percent by weight.  This demonstrates the accumulation of
      chlorine  in the  flue dust  collection system.

      The lead  particulate emission rates based on the EPA Method
      5 test results were:

           -September  26, 1978     0.056 kg Pb/hr
           -September  27, 1978     0.046 kg Pb/hr

      Total stack lead emissions, based on the wet electrostatic precipi-
      tator (WEP) experiments, ranged between 0.042 and 0.12 kg Pb/hr.

      The stack lead particulate emission factors (after control) based
      on the WEP experiments were:

          -September 26, 1978          14 g Pb/metric ton Pb product
          -September 27, 1978          42 g Pb/metric ton Pb product

      Stack chlorine emissions ranged from 1.6 to 7.1 kg/hr.

  •    Stack gas concentrations ranged from 39 to 54 ppm sulfur
      during the test.  This corresponds to sulfur emission rates
      of 6.7 and 9.1 kg S/hr.

  •    Total stack antimony emissions ranged between 0.52 and 0.54
      kg/hr.

  •    Total stack arsenic emissions ranged between 0.0005 and
      0.0013 kg/hr.
                                  15

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Only one high volume area sampler was run on each of the
two test days.  The hi-vol was placed underneath the bag-
house nearest the east fenceline (see Figure 4).  It was
approximately four meters from the east agglomeration furnace
and 80 meters from the east fenceline.  The two twenty-four
hour average lead-in-air levels were:

   -September 26, 1978    12 yg Pb/m3
   -September 27, 1978    18 yg Pb/m3

Stack emissions based on the WEP tests are presented in
Table 3:

  TABLE 3.  STACK EMISSIONS DETERMINED USING WEP TRAIN



Element
Lead
Antimony
Arsenic
Chlorine
Sulfur
September
Concentra-
tion
(yg/Nm3)
1010
4390
4
13300
55700
26, 1978
Emission
rate
(kg/hr)
0.12
0.54
0.0005
1.6
6.7
September
Concentra-
tion
(yg/Nm3)
350
4370
11
59500
77100
27. 1978
Emission
rate
(kg/hr)
0.04
0.52
0.0013
7.1
9.1
The engineering and work practice controls of employee exposure
at this smelter are exemplary.  The effectiveness of this system
of controls is evidenced by the control of employee exposures
to lead in all work activities associated with the SB furnace
to approximately 100 yg/m3 or less.

In general, the local exhaust ventilation systems provided for
the SB furnace are well designed and maintained.  They provide
good enclosure of emission sources, vigorous hood face and
duct transport velocities, access openings and mobility to
allow efficient performance of routine work.

Yard sprinkling and washdown procedures appeared to greatly
minimize entrainment of dust into the air, tracking of muddy
materials into other work areas, and splashing of mud on
employee clothing and plant equipment.

Washdown procedures employed in the SB furnace operating area
did maintain floors in dust free and clean condition.
                            16

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     •  "  The SB furnace process control room was found to be contaminated
          with lead (38 to 54 yg Pb/m3).

The specific measurements and results are presented along with the descrip-
tion of the smelter operation in the following sections.
                                       17

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                                   SECTION 4

                             SOURCE CHARACTERIZATION
SMELTER OPERATING CONDITIONS

     The  SB  furnace  operated  steadily during the entire test period.  The
furnace was  being operated  somewhat  differently than normal because at pres-
ent all slag generated  by the furnace must be stockpiled and a portion recy-
cled.  Permission to dump the slag in a landfill has not yet been obtained.
The chalk (CaCOs) feed  to the furnace was reduced slightly.  The slag still
contained 0.55  percent  lead by weight.   This is well within the range of
normal operation, during which the furnace slag typically contains less than
2 percent lead.

     This lower chalk feed  rate makes the slag less viscous and allows the
slag temperature to  be  maintained at approximately 100°C lower than normal.
The lower operating  temperature makes the furnace operation slightly easier
from an environmental viewpoint because the top temperature can be main-
tained between  100 and  140°C  more easily.  This may result in lower fume
generation at the furnace top and correspondingly lower fugitive emissions.

Feed Characteristics

     The  Bergs^e smelter does not normally receive a large quantity of poly-
propylene-eased  (poly)  batteries in  their feed.   S-oiae poly batteries were
stockpiled for this  test.   The day of  the testing (26 September), the poly
batteries were added to the SB furnace  charge.   The poly batteries comprised
approximately 12.6 weight percent of the total  furnace charge during the
tests.   This  corresponds to 20 percent  of the lead-bearing charge to the
furnace.   The approximate furnace feed  on September 25,  26, and 27 consisted
of the following materials:

                      Whole batteries
                      - polypropylene casre                 12.6% (weight)
                      - hard rubber case                   12.6
                      Battery plates
                      Agglomerated dust (or battery mud)
                      Drosses
                      Return slag
                      Coke
                      Scrap iron
                      Mill scale (PeO)
                      CaC03
                           Total

                                       18

-------
     The furnace feed is prepared  (bedded) using a front end loader.  A layer
of coke is first spread on the floor of the charge bedding area (see Figure 4)
The other components of the charge are then spread on top of the coke.  This
procedure results in an even distribution of coke in each bucket of feed de-
livered to the furnace.

     The target for each charge is 20 metric tons of lead bearing material.
Between three and four charges are required to match the SB furnace produc-
tion.  An attempt was made to record the weight of all materials charged to
the furnace during the test.  However, only a portion of the individual
charge data was made available by the Bergs^e management.  Table 4 presents
the data recorded for five of the charges fed to the furnace during the test.
Note how closely to the target of 20 metric tons of lead bearing material
each charge is prepared.

          TABLE 4.  TYPICAL CHARGE MATERIALS DURING THE TEST PERIOD
                    (Weight in kilograms)
Charge date/time
Feed material
Whole batteries
- poly
- rubber
Battery plates
Agglomerated dust
Drosses
Battery mud*
Return slag
Coke
Scrap iron
Mill scale
CaC03
Subtotal
Lead scrap**
Total
Target
8,000


10,000
1,000
1,000

7,000
1,800
600
2,000
300
31,700
_
31,700
9/25
1200


7,590
9,930


2,050
6,810
1,770
640
2,030
660
31,480

31,480
9/26
0750

4,180
4,260
9,700
1,140
1,260

7,170
1,760
500
2,390
320
32,680

32,680
9/26
1200

4,550
4,260
9,850
840
980

6,760
1,790
660
2,060
280
32,030
4,860
36,890
9/27
0300

4,500
3,650
9,820
620
930

7,060
1,900
460
1,880
80
30,900

30,900
9/27
0830

4,060
3,920
10,370
600
1,180

7,300
1,750
930
2,440
190
32,740

32,740
*Charged instead of Drosses and Agglomerated dust
**Total lead scrap fed to the furnace during test

     Table 5 lists the 'data provided by the Bergs^e management for the week
of the test.  It was stated that only 4,860 kg of the lead scrap listed in
Table 4 was charged during the two test days.  This could not be verified.
The lead scrap needs only to be melted in the SB furnace; no smelting is
required.
                                      19

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            TABLE 5.  REPORTED FURNACE FEED DATA FOR THE TEST WEEK
                      (Weight in kilograms)
Lead-bearing
material
Whole batteries
Battery plates
Battery mud
Agglomerated dust
Lead drosses
Subtotal
Lead scrap
Total
Weekly
Average
265,440
269,330
48,850
16,450
17,440
617,510
71,450
688,960
Daily
average
37,920
38,476
6,979
2,350
2,491
88,216
10,207
98,423
Percent of
charge
38.5
39.1
7.1
2.4
2.5
89.6
10.4
100.0
 Energy  Consumption

      There  are  seven separate items which must be considered with regard to
 energy  consumption per ton of lead in the SB battery smelting system.  Table
 6  lists each of these items and the corresponding fuel or electrical power
 consumption.

      These  values are comparable to a 1 meter (40 inch) cylindrical blast
 furnace which is reported to use approximately 74 kg coke per metric ton of
 lead  product, an afterburner, but no fuel for air preheating.  Total energy
 use for the 1 meter blast furnace is approximately 5.67 x 109 J/metric ton
 Pb compared to  4.81 x 109 J/metric ton Pb for the SB furnace.  Additional
 energy  is supplied in the SB furnace by the polypropylene and rubber battery
 cases.

 Production  Data

      The average SB furnace production rate during the test period (26 and
 27 September) was approximately 70.5 metric tons per day.  However, as can
 be seen in  Table 1, at least 4.86 metric tons of lead scrap (pipes, flashing,
 drains, etc.) were included in the furnace feed during the test period.  By
 comparison, the production rate for a 1'meter blast furnace would be approxi-
 mately  29.5 metric tons per day.  The production rate (metric tons/day) per
 square meter of furnace hearth cross-section is 17.6 for the SB furnace and
 37.3  for the 1 meter blast furnace.

     Table  7 presents the production data provided by the Bergs^e management
 for the week of the test.  Table 8 presents production data from a 91-day
campaign.
                                     20

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                     TABLE 6.  ENERGY CONSUMPTION DATA


Item
Coke
Oxygen
Air preheater
Afterburner
Agglomerators
Electricity
Vehicles
(2 front end
loaders, 1
fork lift)
Total

Consumption
units
kg
Nm3
liters (L)
liter s(L)
liter s(L)
joules (J)
liters (L)




Units per
metric ton
of lead
71.01
40.83
24.10
39.19
2.46

2.15
(estimate)




10 6 Joules
per unit
30.14
6.82 x 10~S
39.39
39.39
37.91

38.74




10 6 Joules
per metric
ton of lead
2140
0.0003
950
1540
93
0.42*
83



4806
*Based on 91-day average production of 75,769 kg/day
    TABLE 7.  REPORTED PRODUCTION DATA FOR THE WEEK OF SEPTEMBER 24, 1978
Furnace
output
Lead bullion
Flue dust
Slag
Matte
Weekly
production
482,300
21,500
271,000
95,200
Daily
average
68,900
3,071
38,714
13,600
Recorded data
25 Sept
81,675
2,320
41,800
14,686
26 Sept
79,200
2,900
37,688
1.3,241
27 Sept
61,875
3,480
38,716
13,601
Average
74,250
2,900
39,401
13,843
         TABLE 8.  REPORTED PRODUCTION  DATA FOR A 91-DAY CAMPAIGN
                   (Weight in  kilograms)
Furnace
output
Lead bullion
Flue dust
Slag
Matte
Weekly
production
6,895,000
614,300
4,195,400
1,474,000
Daily
average
75,769
6,750
46,103
16,198
                                      21

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Furnace Operation

     As mentioned earlier, the SB furnace operated steadily during the entire
test period.  A number of parameters were recorded in order to show how the
furnace conditions varied during the test period.  These are listed in Table
9.

     The data listed in Table 9 are typical for the SB furnace operation.
The oxygen enrichment of the blast air is small, between 50 and 120 Nm3/hr.
However, the oxygen does help reduce the amount of blast air required, there-
by reducing the velocity of the gases rising through the furnace shaft.  The
oxygen-enriched blast air pressure ranged from 1030 to 1180 mm H20.  This is
slightly higher than the desired 800 to 1000 mm H20 operating pressure range
but did not cause any noticeable problems.

     The major factor in reducing the quantity of process gas in the furnace
is the air preheater.  By preheating the oxygen-enriched air to between 470
and 500°C in an external preheater, less coke is required in the furnace.
Thus a portion of the combustion products are eliminated along with the
combustion air required to burn the coke needed for air preheating.

     The furnace top temperature is kept quite low relative to other blast
furnace operations.  The process gas temperature ranged between 89 and 189°C
during the test period.  The low top temperature prevents the battery case
material from igniting.  Should the case material happen to ignite or begin
smoldering, additional material is charged to the top of the furnace and the
blast air is adjusted.  The low top temperature also minimizes the amount; of
fuiae  exiting in either the process or hygiene gas streams.

     The process gases exited the furnace between 89 and 180°C during the
test period.  The hydrocarbons in these gases are combusted in the oil-fired
afterburner.  The gases exit the afterburner between 700 and 8008C.  Fresh
air is then added through a small damper, cooling the gases to approximately
430°C.  The gases cool further in the ductwork and are then mixed with the
cooler furnace hygiene air.  The ratio of process gas to hygiene air is
approximately 1:2.  The gases then enter the four baghouses at a temperature
below 130°C.  If the temperature of these gases rises above 130°C, cold
ambient air is admitted via a small damper.  This is done to protect the
felted polyester used as filter material.  The gases cool in the baghouse
and exit the stack between 82 and 90°C.

HIGH VOLUME AIR MONITORING

     One high volume (hi-vol) air sampler (GMWL model #2000H)  was placed
under the easternmost baghouse near the two agglomeration furnaces (see
Figure 4).   The hi-vol was approximately 80 meters from the smelter fence-
line.   No ambient measurements were permitted at the fenceline because of the
close proximity of the rotary department (Building #3), the old smelter, and
the motorway which lies approximately 200 meters from the fenceline.

     Two samples were collected during the test period.  Table 10 presents the
test results.


                                      22

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                TABLE  9.   OPERATING PARAMETERS RECORDED DURING
                           THE CHARACTERIZATION TESTS
Parameter
Oxygen flow
Oxygen/air pressure
Oxygen/air temperature
Blast air (In)
Water Jacket (In)
Water Jacket (out)
Furnace top (process)*
Afterburner (Inlet)
Afterburner (outlet)
Afterburner (outlet
after fresh air dilution)
Afterburner (outlet before
mix point)
Furnace top
hygiene air (avg.)
Bagbouse inlet temp.
(avg,)
Stack temperature
Stack gas flow
Units
Nm'/hr
mm H20
•c
HmVhr
°C
°C
°C
"C
•c
"C
•c
°C
ec
"C
HmVhr

9/25/78
1400
-
1050
474
3340
52.5
62
89/98
90
700
460
330
27
132
84
-

9/26/78
0830
58
1030
495
3720
47.5
64.5
101/180
150
-
430
290
27
110
85
120,000
Date/time
9/26/78
1500
114
1080
472
3240
48.5
59
93/100
100
750
415
290
25
104
82
120,000

9/27/78
0600
56
1030
495
3740
-
-
77/169
175
800
460
305
26
115
85
115,000

9/27/78
1500
97
1180
479
3340
48
57
143/105
135
800
435
320
26
117
90
120,000
^Temperatures at both process gas ducts exiting the furnace.
                                        23

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                  TABLE  10. HI-VOL AREA SAMPLING RESULTS
Date
26 Sept 78
27 Sept 78
Sampling
period
(hr:min)
23:00
25:56
Total particulate
collected
(yg)
197,700
201,900
Total lead
collected
(yg)
24,500
41,600
Ambient air
concentration
(ug Pb/m3)
12
18
It is important to note that the sprinkler system failed during the second
test day.  This caused the pavement to dry.  This may have caused the in-
crease in total lead-in-air from 12 to 18 yg/m3 and caused the percentage
of lead in the collected particulate to rise from 12 percent on 26 September
to percent on 27 September.  These datk highlight the importance of washdown
procedures in minimizing fugitive windblown dust in the smelter yard.

     An extensive fenceline monitoring program was not conducted because of
the close proximity of the old smelter and a major motorway.  It was felt
that fenceline monitoring data would have little significance because of
interference from these other sources.

STACK SAMPLING

Description of Sampling Locations

     Stack sampling was performed from an instrument platform approximately
25 meters from the base of the stack.  The stack is a double wall design
(see Figure 5).  The inside diameter of the interior stack is 2.5 meters
and the inside diameter of the outside stack is 4.8jneters.

     The instrument level was equipped with four access ports to the interior
stack, located at 90° intervals.  Three ports were unavailable for use be-
cause plant instrumentation was installed in the ports.  The one available
port was located in line with an instrument access hole through the outer
stack.  This allowed the use of a probe of sufficient length to traverse one
entire diameter of the inner stack.  The sampling location was approximately
ten diameters upstream and downstream of any flow disturbances.  Velocity
measurements also indicate that the gas flow at the sampling level was
laminar.  As a result, making a stack traverse across only one diameter
(rather than two at 90° angles) should not affect the validity of the
sampling results.  Twelve traverse points were used during sampling.  The
distances of the traverse points from the inside wall at the sampling port
are listed in Table .11.
                                      24

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                                                               CONCRETE
                                                                 SHELL
                                 DECK
                               25 METERS
                              ABOVE GROUND

LIFTING AID
OUTSIDE STACK W
                   Figure 5.  Stack cross-section.
                                                                02-3762-1
                                        25

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                TABLE 11.   TRAVERSE POINTS MEASURED FROM THE
                           INSIDE WALL AT THE SAMPLING PORT1
               Point               Location (cm)
1
2
3
4
5
6
7
8
9
10
11
12
4.6
16.5
29.2
44.5
62.2
88.9
161.3
187.3
205.7
220.4
233.1
244.5
      points are rounded to the nearest 0.6 cm.
 EPA Method  5

      The  EPA Method  5  sampling train pictured in Figure 6 was used to deter-
 mine the  following:

               Average stack temperature and velocity,

               Lead  particulate emissions, and

               Total sulfur and chlorine emissions.

 Stack Temperature/Velocity Determination—

     The Method 5 sampling train was used to determine the average temperature
and velocity in the smelter stack on September 25,  1978.   A traverse of only
one radius was possible because the other ports in the stack were in use.
                                      26

-------
        Probe Assembly
Particulate
Collection
                  STACK
     PROBE
                              HEATED
                               AREA
     THERMOMETER
     REVERSE-TYPE
     PITOT TUBE
          PITOT MANOMETER
 fllTEH

 HOtOER
                        THERMOMETERS
                                                      Vapor Collection

                                                IMPINOER TRAIN OPTIONAL. MAY BE REPIACEO
                                                    •T AN EQUIVALENT CONDENSER
                                                                THERMOMETER
                   ORIFICE
                                                     VACUUM
                                                     LINE
                                           MAIN
                                           VAIVI
                     DRV OA8 METER
                                       Metering
                       Figure  6    EPA 5 sampling  train.
Lead Particulate Stack Emissions—
     Stack participates were collected on  a glass fiber filter  heated to
121°C  (250°F) in a thermostated oven.  Both the filter and probe were heated
during  sampling.  Table 12  presents the  results of this experiment for both
test days.   It is important to note that the average grain loadings for both
days were  identical.  This  indicates that  the baghouse was operating normally
and was allowing a constant amount of fine particulate to pass  through with
the gas stream.

     An analysis of the particulate matter collected on the  filter was made
for lead and chlorine.  Lead analyses were performed for these  and all other
experiments using atomic  absorption spectrophotometry.  Chlorine analysis was
performed  using a colorimetric determination.  The emission  rates were 56 and
46 grams of lead per hour on 9/26/78 and 9/27/78 repectively based on the
particulate collected on  the filter.  Table 13 summarizes the results of the
lead particulate emissions  testing.  No  chlorine could be detected in the
particulate material.
                                        27

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TABLE 12.  EPA METHOD 5 RESULTS
Average velocity
determination
Date 26 Sept 78
Time 0910-0935
Sample duration 25 min
Sample volume at meter
Avg. meter temperature
Meter pressure 762 mm Hg
Avg. stack temperature 85°C
Stack pressure 761 mm Hg
Avg. gas velocity 9.50 m/s
Total gas flow 1.26 x 10s Nm3/hr
Moisture content of gas
(Volume %) 2.0
Gas molecular weight 28.2
Mass collected, filter
Mass collected, probe
Mass collected, total
Nozzle diameter
Nozzle area
Stack diameter
Stack area
Avg. sample velocity
at nozzle
Particulate concentration
Particulate mass rate by
area
Particulate mass rate by
concentration
Farticulate mass rate
Percent isokinetic
Particulate, chlorine, and sulfur
determination
26 Sept 78
1110-1210
1 hr
0.889 m3(0.802 Nm3)
31"C
762 mm Hg
898C
761 mm Hg
9.34 m/s
1.22 x 10s Nm3/hr
2.0
28.2
3.28 mg
26.08 mg
29.36 mg
0.617 cm
2.99 x 10~5 m2
2500 mm
4.91 m2
10.07 m/s
36.6 mg/Nm3
4.82 kg/hr
4.47 kg/hr
4.64 kg/hr
108%
27 Sept 78
0808-0944
1 hr 36 min
1.44 m3(1.31 Nm3)
31°C
764 mm Hg
87°C
764 mm Hg
9.08 m/s
1.19 x 10 5 Nm3/hr
2.4
28.1
4.72 mg
43.20 mg
47.92 mg
0.617 cm
2.99 x 10"5 m2
2500 mm
4.91 m2
10.20 m/s
36.6 mg/Nm3
4.92 kg/hr
4.36 kg/hr
4.64 kg/hr
112%
               28

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             TABLE 13.  LEAD PARTICULATE EMISSIONS TEST RESULTS
Date
9/26/78
9/27/78
Gas voluM
sampled
(NmJ)
0.802
1.31
Stack gas
flow
(NmVhr)
1.22 x 10*
1.19 x 10s
Total partic-
ulate flow*
(kg/hr)
4.47
4.36
Pb particulate
collected t
(Vg)
365
505
Pb flow
rate
(g Pb/hr)
56
46
    *Using measured concentration
    t On Filter
     These results indicate that the baghouse is extremely efficient in
removing lead particulate.  There appears to be other material, perhaps a
condensing fume, which accounts for most  (^99%) of  the particulate collected.
Antimony pentachloride (SbCls) may constitute a portion of the particulate
collected.  SbCl5 boils at 79°C and may be condensing between the baghouse
exit and the 25 meter level of the stack.

Sulfur and Chlorine Stack Emissions—
     Sulfur and chlorine compounds were collected in a series of three im-
pingers which were placed behind the heated filter  in the Method 5 sampling
train (see Figure 6).  Two impingers in series containing 1% NaOH followed by
an impinger containing 6% H202 were used  for the experiment.  The filter used
to collect lead particulate was also analyzed for chlorine.  A Dionex® ion
chromatograph was used for the sulfur determinations.  A colorimetric deter-
mination using mercuric thiocyanate was used for the chlorine determinations.

     The results of the gaseous sulfur and chlorine determinations are pre-
sented in Table 14.  The sulfur emissions are fairly constant, 6.7 and 9.1 kg
S/hr.  The chlorine emissions, however, varied by a factor of 4.4.  This may
be due in part to a larger portion of flue dust or  flue dust containing a
higher percentage of chlorine being recycled during the second day.
        TABLE 14.  GASEOUS SULFUR AND CHLORINE  EMISSION TEST RESULTS

Date
9/26/78
9/27/78
Gaa volume
sampled
0.802
1.310
Stack gas
flow
(Nm'/hr)
1.22 x 10s
1.19 x 10s

•g
collected
44.1
100.0
Sulfur
gas cone.

-------
     The sulfur emissions  (as SOX) were checked on September 27 using
 another sampling  train  containing a  filter followed by two  6% H202  impingers.
 The results of this test showed 41 ppm SOX in the gas stream, corresponding
 to an emission rate of  7.0 kg S/hr.  This is in good agreement with the
 two values listed in Table 12.

     The sources  of the sulfur in the stack gas are the rubber battery cases,
 battery acid  or mud, coke, and afterburner and agglomeration furnace fuel
 oil.  The average SOX concentration  in the stack includes the dilution effects
 of the hygiene air, the afterburner  and agglomeration furnace Combustion
 products, and any additional cooling air.

     The results  of the chlorine determinations showed emission rates of 1.6
 and  7.1 kg Cl per hour.  These results are discussed in conjunction with the
 results of the wet electrostatic precipitator tests in the  following section.

 Wet  Electrostatic Precipitator (WEP)

     The wet  electrostatic precipitator (WEP) sampling train shown  in Figure
 7 was developed by Radian  Corporation specifically for trace metal  sampling.
 An electrolyte  is circulated through a round bottom flash and a vertical
 glass cylinder by a peristaltic pump (see Figure 8).  The walls of  the
 cylinder are  wetted by  the falling film of electrolyte.  A  thin platinum
 wire is  suspended in  the center of the glass cylinder.  A high voltage of
 1.2 to 15 kV-DC causes a corona discharge at the center electrode.  The gas
 entering the  WEP  is first  scrubbed and cooled in the round  bottom flask.
 PartiCulates  and  mist not  retained here are electrically charged in the glass
 cylinder,  collected in  the falling film and washed into the electrolyte
 reservoir.  This  sampling  device does not clog like a filter or a thimble,
 and  no analytical background corrections are necessary since no extraneous
 material is introduced  as  is the case with filters.  The probe consists of  a
 teflon nozzle and is  teflon lined.   Teflon tubing is used to connect the
 probe with the WEP.  All the lines are rinsed after sampling and combined in
 the  WEP.  The WEP is  followed by a train of nine impingers.  The impingers
 contained:

          1)  20%  HN03
          2)  20%  HN03
          3)  Dry
          4)  10%  NaOH
          5)  10%  NaOH
          6)  Dry
          7)  61 E202
          8)  Dry
          9)  Silica gel (dessicant)

 A pump and a  dry  gas meter complete  the assembly.  The WEP train was operated
isokinetically at a single point of average velocity in the stack.
                                      30

-------
Teflon
Nozzle
          Teflon lined Probe
                       Teflon
                       Tubli
                                                  Acid Implngers
                                fl)
X
                               Wet Electrostatic
                                  Frecipitator
                                                           Caustic Implngers
                      llydroRonperoxi.de
                         Impinger
        Ice Bath
                                                                    Dry
                                                                  ImpIngers
                                 Silica C«l
                                  laplngcr
                                                                          Fine
                                                                    Adjustment Valve
                                                             Coarse
                                                        Adjustment Valve
                                                                           Pump
          Figure  7.  Schematic of  the integral WEP  sampling train.
                                           31

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         SAMPLE
         OUTLET
PERISTALTIC
   PUMP
                                   HIGH VOLTAGE
                                   POWER SUPPLY
                                 PLATINUM
                                 ELECTRODE
                                        Falling Film of
                                        Slectrolvte
                                            SAMPLS
                                             INLET
                                CIRCULATING
                               ELECTROLYTE
                                RESERVOIR
    Figure 8.  Wet  electrostatic precipitator.
                          32

-------
     Table 15 presents the results of the Method 5 WEP tests.  All analyses
for lead, antimony, and arsenic in these and all other samples were performed
using atomic absorption spectrophotometry.  The emission rates listed are
total emissions, including both gaseous and particulate species.  It is im-
portant to note that the total lead emission rates listed in Table 15 for 26
September are 2.2 times higher than those listed in Table 13 for the solid
particulate in the Method 5 filter catch.  This indicates that volatile lead
compounds may be escaping the baghouse in addition to the normal fine partic-
ulate matter.  The material collected in the probe wash (see Table 12) may
account for part of the. difference in the WEP and Method 5 lead emission
values.  However, the material collected in the probe wash appeared to be
organic in nature.  Unfortunately, no analysis of the probe wash was made.
Consequently, an accurate comparison of the WEP and Method 5 results cannot
be made.

     TABLE 15.   TOTAL LEAD, ARSENIC,  AND ANTIMONY EMISSION TEST RESULTS
Emission rates



26
27


Date
Sept 78
Sept 78
Volume of
gas sampled
(Nm3)
3.76
9.23
Total
gas flow
(Nm'/hr)
1.22 x 10s
1.19 x 10!
Lead
ng
collected
3800
1140

g Pb/hr
123
42
Arsenic
Ug
collected
15.3
35

g As/hr
0.50
1.29
Antimony
Pg
collected
16,500
14,100

g Sb/hr
535
519
     Arsenic emissions are relatively low.  This is to be expected because of
the small amount present in the feed materials.

     The antimony emission rates of 535 and 519 grams per hour were unex-
pectedly high.  These emissions can be attributed to the presence of chlorine.
It is believed that SbCl5 is  the compound being emitted.  SbCl5 boils at
79°C and may pass through the baghouse as a vapor.  If no chlorine were
present, virtually no antimony emissions would be expected.  Antimony oxide
Sb203, sublimes at 1550°C and would not be volatile at stack temperature.

Stack Emission Factors

     In general, the measured emission rates for all species were quite low.
The stack emission factor ranges presented in Table 16 were calculated based
on a lead production rate of  70.5 metric tons of lead per day the Method 5
experiments for chlorine and  sulfur, and the WEP experiment emission rates
for the metals.  Of course, these results are for two days of normal opera-
tion.  Different feed materials or operating conditions (e.g., only three
baghouses operating) could significantly alter these results.
                                     33

-------
    TABLE 16.  STACK EMISSION FACTORS FOR THE SB BATTERY SMELTING FURNACE

      Element                  Emission factor (g/metric ton Pb product)

    Lead                                       14 to 42
    Arsenic                                   0.17 to 0.44
    Antimony                                      180
    Sulfur (as S)                             2300 to 3100
    Chlorine                                   550 to 2400
MATERIAL FLOW

     The determination of the flow of lead, antimony, arsenic, chlorine and
sulfur through the SB furnace was a key part of the characterization study.
Data gathered on the concentration of these elements in the smelter input
and output can help identify potential problems and advantages of the SB
furnace and the agglomeration furnaces.

     Two days of sampling data were collected for the material flow deter-
mination.  The furnace had been running steadily for more than a month
prior to the testing.  The addition of polypropylene-case batteries to
the furnace charge was a change from normal operation, but no major change
in furnace emissions were either expected or observed.

Feed Characterization

     An attempt was made to record the weight of all materials in each
charge during the test period.  However, data on only five of the charges
were made available by the smelter management.  As a result, an exact
material balance could not be completed for the test period.

     Samples of each type of feed material were collected for analysis.  The
samples taken are by no means homogeneous, integral samples.  The feed
materials to most secondary lead smelters vary daily as different brands and
different type batteries are received for smelting.  It was not possible to
collect an "average" or "homogeneous" sample representing two days of
smelting.  On a monthly or yearly basis, a "representative" feed could be
determined.

     As a result, grab samples of what appeared to be a typical feed sample
from the charge bedding floor were taken along with samples from each pile
of material used to prepare the charge.  Table 17 presents the results of
the analyses of each of these samples.
                                     34

-------
               TABLE 17.  AVERAGE FEED MATERIAL  COMPOSITION
                                      Pb     Sb     As      S      Cl
           Material         Date    (Wt %)  (ppm)  (ppm)  (Wt %)  (ppm)
Feed composite
Battery plates t
(composite)
Return slag

Flue dusttt

Battery mud
Drosses
Coke
Rubber case
Polypropylene case
PVC separator

9/26 &
9/27
9/26
9/27
9/26
9/27






63.0
59.2

0.52
0.58
64.9
59.8
65.0
72.1




1.2%
7420

150
200
2295
1780
1:01%
4.26%




230
416

74
107
5
3
231
298




2.1
0.6

1.0
0.8
0.6
0.4
1.3
2.6
0.7
1.4


310
1200

4430
7100
26.0%
24.2%
5500
3600

370
370
51.5%
     tNormal values range from 68 to 72 percent lead.  The low value
        measured here may be caused by sampling errors.
    ttNormal chlorine content of flue dust reportedly ranges between
        12 and 15 percent.

Product Samples

     Samples of flue dust, slag, matte, and bullion were collected as they
were tapped from the furnaces.  However, the matte and slag samples taken
directly from the furnace did not have a chance to settle completely.  As a
result, additional samples were collected from the cooled slag pots after
the matte and slag were separated.  The results of the product sample analy-
ses are presented in Table 18.  Analyses for lead, antimony, and arsenic
were performed by atomic adsorption spectrophotometry.  Sulfur analyses were
performed with a Leeko sulfur analyzer.  Chlorine analyses were performed
by titration with AgNOa (the argentometric method).
                                     35

-------
                      TABLE 18.   PRODUCT STREAM ANALYSES
Material
Bullion


Matte
(from
Matte
(from
Slag
(from
Slag
(from



yard)

furnace)

yard)

furnace)
Flue dust


Date
9/26
9/27
9/27
9/26
9/27
9/26

9/26
9/27
9/27

9/26
9/27
Pb
(Wt
98.
99.
96.
4.
6.
10.

0.
0.
0.

64.
59,
%)
6
2
7
4
2
9

52
58
54

9
8

1
2
2
1
1
1





Sb
(ppm)
.96%
.24%
.10%
.22%
.28%
.68%

150
200
440

2295
1780
As
(ppm)
16
107
5
1685
1585
1685

5
3
99

5
3
S
(Wt %)
0.
0.
0.
19.
18.
10.

1.
0.
1.

0.
0.
19
11
16
62
82
98

04
79
56

61
36
Cl
(ppm)
268
275
210
5220
2350
2940

4430
7100
6930

26.0%
24.2%
Elemental Partitioning

    A detailed material balance for the test period could not be completed
because weights of several furnace charges were not made available.  However,
the results presented in Tables 4, 7, 17 and 18 do allow an estimate to be
made of how the elements present in the furnace are distributed in the
furnace products.  The partitioning effect of the SB and agglomeration fur-
naces is shown in Table 19.  Of course, chlorine was accumulating in the
furnace system during the test period.  Chlorine is periodically removed
from the system by leaching the flue dust or by removing a batch of flue
dust for use in another smelting process.  The numbers in Table 19 represent
the elemental partitioning several weeks after the last batch of flue dust
was removed.

        TABLE 19.  ELEMENTAL PARTITIONING IN THE SB SMELTING FURNACE
           Feed    Intermediate streams
         material*  Flue dust    Slag
 Element  (kg/day) (% of feed material)
      Product streams
Lead metal  Matte   Stack gas
    (% of feed material)
Lead
Antimony
Arsenic
Sulfur
Chlorine
Total
79000
1500
29
2600
140
81814
2.52
0.43
0.04
0.59
580.2

0.27
0.44
0.53
13.28
159.6

87.68
98.49
10.38
0.14
17.83

0.90
1-1.15
75.66
98.00
36.81

0.0025
0.84
0.07
7.20
75.83

*Based on average feed for sampling period, 26 and 27, September, 1978, and
 analytical results in Tables 14, 15, 17 and 18.
                                      36

-------
                                  SECTION 5

                        CONTROL TECHNOLOGY ASSESSMENT
DESCRIPTION OF EQUIPMENT AND CONTROLS

     Section 2 of this report contains descriptive information concerning the
SB shaft furnace and controls.  This section emphasizes the features of the
SB furnace and associated equipment which are important for the control of
employee exposures to lead and other workroom contaminants.

Receipt of Raw Materials

     The containment and suppression of airborne contamination inherent in
handling feed materials is an integral feature in the design of this second-
ary lead smelting complex.  Figure 9 presents an overview of the SB Furnace
Building and the Charge Storage and Preparation Building.  Materials are
received by truck and are usually unloaded in the paved yard area.  Here the
materials are separated and then transferred into the Charge Storage and
Preparation Building by large rubber-tired, diesel-fueled front-end loaders.
Industrial lift trucks are also utilized in the receipt (off loading) of
feed materials.

     The paved yard area is kept wet by water sprinklers.  Many of the
sprinkler heads are mounted at elevated locations on the sides of buidings.
The sprinklers activate automatically at preset intervals.  The fixed
sprinklers are supplemented by mobile sprinkling trucks and wet sweeping
units.  Water hoses are also used by employees to wet down surfaces and to
clean up mud, etc.  Wet suppression of yard dust is feasible at this smelting
location since the climate is moderate with infrequent freezing weather.

Charge Storage and Preparation

     The Charge Storage and Preparation Building (refer to Figure 9) is a
large concrete structure with concrete floors and multiple roll-up access
doors.  To aid in dust suppression the floors of this building are periodi-
cally wetted using water hoses.  Feed materials are stored in large bins
separated by concrete partitions.  No processing of feed materials takes
place in this building.  Those batteries which are received in whole form
are not decased and remain somewhat intact through the materials handling,
charge bedding and furnace charging operations.  Other charge materials have
been processed by scrap dealers, etc.  These materials (battery plates, etc.)
are mixed with other materials in the bedding procedure.
                                       37

-------
                          Charge materials
                          storage —^
    /-—"\
         Charge bedding area
         Charge storage and
         preparation building
                 Air
              monitoring
               location
                                                       Recycle slag
                                                              pile
Feed materials
receiving area
(paved)
                  Charge
                 materials
                  storage
                Roll-up doori


             Furnace control room






                        SB furnaa
           Ramp to second level
             charging station
                -Slag ladle
                 dumping area
         o o
           o
  oo o o o o o o
  oooo o o o o
  OOOOOO OO
Slag ladle final
cooling area

SB furnace building
    Baghouses
                                                        Afterburner
                                                                        02-4447-01
 Figure 9.   Overview of  SB  furnace building and  charge storage
              and preparation building
                                       38

-------
     One rubber-tired, diesel-fueled front-end loader is routinely assigned
to this building and performs materials off-loading, storage in bins,
charge bedding and furnace charging.  This front-end loader is equipped with
a filtered air supply to the operator's cab.

SB Furnace Charging Facilities

     The charging of the SB furnace is performed  on the second level of the
SB Furnace Building  (refer to Figure 9).  An  indoor ramp connects this area
with the Charge Storage and Preparation Building.  Charge materials are trans-
ported via front-end loader up  this ramp  from the charge bedding area and
deposited in the top of the furnace.  This charging area is isolated from
the other work areas in the SB  Furnace Building by a concrete floor.

     The top of the SB furnace  is provided with an exhaust hood which con-
tinually controls emissions from the furnace  top.  Figure 10 shows a sketch
of the SB furnace charging hood.  This hood is part of the integrated venti-
lation control system which is  schematically  shown in Figure 11.

     Performance of the ventilation system is monitored through use of sens-
ing devices (static pressure, temperature) which  are connected to an opera-
tor's control panel located on  the process control room on the ground level
of this building.  Additionally, closed circuit TV cameras are trained on
the charging hood with TV monitors provided in the process control room.
This TV system can be used to monitor the performance of the charging hood
and also determine the need to  add more material  to the furnace.

     Aside from the front-end loader operator, no employee routinely works
in the SB furnace charging area.

SB Furnace Operating Area

     Most of the work involved  in operating the SB furnace is performed in
the ground level work area of the SB Furnace  Building.  A sketch of this
work area is shown in Figure 12.  As can  be seen  from the figure, the pro-
cess or operator's control room is located on this level together with the
lower portion of the SB furnace.

     All of the activities normally performed at  the base of a vertical shaft
smelting furnace are performed  in this work area.  Slag and finished hard
lead are tapped from the furnace into receiving ladles or crucibles.  Emis-
sions from these operations are controlled by local exhaust ventilation hoods
which are part of the integrated ventilation  system for the SB furnace
previously referred to in Figure 11.
                                       39

-------
                                                 Collecting
                                                 plenum for
                                              charging hood I
             Flaps of conveyor
             belt material
Area monitoring
location   /6Y"*
                                        Fold down lids
                                        1  (in UP
                                        I position)
                                                                              Furnace hot flue
                                                                              gas risers
                                                       Ducts from local exhaust
                                                       hoods on lower level
                                                                                     Area monitoring
                                                                                     location
                                                                      Metal plates
Sidewall of
SB furnace

    Figure 10.  Furnace charging hood  (Hood  I)
                                                                                              02-4448-01

-------
                                          Baghouse
                                          No. 2
                                    Baghouse
                                    No. 1
     Baghouse
     No.  3
       Baghouse
       No. 4
                                                                                        02-4449-01
                                         Afterburner
                              SB furnace
Figure 11.  Key to local exhaust ventilation hoods
            associated with SB furnace and agglom-
            eration furnaces.
                                                               Agglomeration
                                                               furnaces
                                                           Hood
          Description
A,B,C,D   Slag tapping hood

E,F       Secondary slag tapping
          hood (fugitive emission
          plenum)

G         Finished metal tapping hood

H         Finished metal ladle cooling
          hood

I         Charging hood

J,K       Agglomeration furnace ladle hood

-------
                                       f Roll-up  doors -^

                                 -d	J	a	*-
                                                               Spiral
                                                               Stairs to
                                                               Charging
                                                               Level
               Afterburner
                            
                                Tuyere fugitive
                                emission hood    Metal
                               /                tapping

                               \    *<£>."hooda
                                          D

                                  Shaft  pi
                                 _       ii
                                 r urnace ^
                               • •y*g"a^^V" 'y'"1*1" •
                               &i*SS&
                                  SZLa^^^fc^
                                  r
                                    V. Slae
                                           Slag  tapping
                                           hoods
                                             Process control
                                                  room
      Roll-up door
     OArea Air Monitoring
     Station
o
                                            Charge Storage and
                                            Preparation Building
Noise Measurement
Location                                                      02-4450-01

Figure 12.  SB furnace ground  level  work area,  SB furnace building.
                                      42

-------
     Figure 13 shows an overview of  the  local  exhaust ventilation controls
associated with the base of the SB furnace.  Hood F assists in the capture
of emission from slag tapping and from tuyere  punching operations.

     Slag and finished metal ladles  are  handled by forklift truck.  The
floors in this operating area are frequently washed down through use of a
water hose.  The four furnacemen and one furnace foreman do not wear res-
pirators while working in this area  though they are accessible for emergencies

     The process control room is located adjacent to this work area.  It is
not equipped with special filtered ventilation and opens directly to the
process work area.  Furnace operating personnel spend varying amounts of
time in the control room where consumption of  beverages and smoking is
permitted.

     Also located in this general work area is the oil-fired afterburner for
the SB furnace flue gas control system  (refer  to Figures 11 and 12).  No con-
trols other than the process ventilation system are provided for this after-
burner.  The final stages of the afterburner allow entry of dilution air for
cooling and pressure relief in the event of explosion.  Agglomerated material
from the afterburner is collected in a slag ladle and emptied as necessary.

SB Furnace Integrated Ventilation System

     Several references have already been made to the integrated ventilation
system for the SB furnace as depicted in Figure 11.  The system is "inte-
grated" in that it handles both furnace  flue gases and air collected by local
exhaust ventilation hoods.

     The SB furnace uses preheated blast air which is injected into the
furnace through the tuyeres shown in the sketch in Figure 13.  The flue gas
stream beyond the smelting zone in the furnace rises and is collected by a
header (doghouses) just below the charging level in the furnace.  The flue
gases captured by these doghouses are ducted away from each side of the
furnace as shown in Figures 10 and 11.   Each of the flue gas risers is
steeply angled to an apex where the  two  streams merge and flow down to the
afterburner located at ground level.  The steep inclination of these ducts
reportedly makes them self cleaning, however,  occasional cleaning may be
required.

     After being processed through the afterburner, where some dilution air
enters, the flue gas stream is combined  with the air drawn in through the
local exhaust ventilation hoods.  The quantity of local exhaust air mixed
with the flue gas stream is regulated to keep  the stream temperature below
130 °C (266 °F).  Shortly thereafter this air  stream is joined by the flue
stream from the flue dust agglomeration  furnaces and then is processed
through baghouse filters.  The baghouses are equipped with doors for cleaning
and bag replacement.  Following the  baghouses  the exhaust stream is pulled
through large exhaust fans and then  ducted to  a tall stack.
                                     43

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      Flexible rubber
      curtains
     Furnace tuyeres
Slag tapping hood
swung away from
slag tap
(Hood C)


        Slag ladle
                                                Fugitive emission
                                                plenum (secondary
                                                slag tapping hood)
                                                (Hood F)
Slag tap     /        I
and launder/          \
                                                    Metal plates
                                                                                          Finished metal
                                                                                          tapping hood
                                                                                          (Hood G)
                                                                  Finished  metal
                                                                  ladle cooling
                                                                  hood  (Hood  H)
                                                       Finished metal
                                                       ladle carrousel
                                                                               Slag tapping hood
                                                                               (Hood D)
                                                                                             02-4451-01

    Figure 13.  Overview of exhaust ventilation controls for the tapping of slag and finished  metal.

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Flue Dust Handling

     Flue dust collected  in  the  baghouse filters is  screw conveyed to the
agglomeration furnaces  shown in  Figure 11 and Plate  4.  As stated earlier,
the flue gas emissions  from  these furnaces are collected  by the integrated
ventilation system.  Local exhaust ventilation in the  form of a canopy hood
is provided over  the slag ladle  as shown in Figure 14.

     As slag ladles are filled with agglomerated flue  dust,  they are removed
by forklift truck.  The agglomerated material is stored inside to prevent it
from weathering and returning to a dust form.

DESCRIPTION OF EMISSION SOURCES  AND POTENTIAL EXPOSURE

Materials Handling Emissions

     At this smelter there are several situations where employees can be ex-
posed  to contaminants  emitted by materials handling.   The following paragraphs
describe these situations, the employee interaction  with  the emission source
and the control of the source.

Receipt of materials—
     Off loading  and handling of raw materials can generate airborne contami-
nation.  A varying number of employees may participate in raw material re-
ceiving at this smelter.  Usually an equipment operator is involved who may
be the individual assigned to the Charge Storage and Preparation Building or
a person who routinely operates  a front-end loader in  the yard areas of the
plant.  Occasionally,  a general  laborer or other person may assist in raw
material unloading.

     As stated earlier the yard  area is paved and kept wet.  Prompt attention
to moving received materials to  their respective inside storage areas is ex-
ercised.  At the  time  this evaluation was conducted, scrap batteries were
also stored in piles outside the Charge Storage and  Preparation Building.
Employees do wear respirators when handling dusty materials.  One of the
front-end loaders is equipped with a filtered, air-supplied cab.  Contamina-
tion tracked into the  cabs of front-end loaders is periodically cleaned by
flushing the cabs with water sprayed from a hose. Hoses  are also used to
flush  the yard area with  water to remove heavy mud accumulations.  Addition-
ally,  the yard is routinely  swept with a large mechanical wet sweeper and
wetted using a sprinkler  truck.

Storage and Handling of Charge Materials—
     At this smelter charge  materials are largely stored  and handled inside.
Contamination generated by handling charge materials is largely confined to
the Charge Storage and Preparation Building.   Stockpiles  of materials within
the building are  kept  wet.   One  employee utilizes a  front-end loader with a
filtered, air-supplied cab to move materials.   Contamination tracked out of
this building by  the front-end loader is controlled  by the routine yard
clean-up procedures.
                                      45

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             Refractory lined
             agglomeration furnace
             exhaust flue
             (30 cm, 12 in I.D.)

                                v
          Swing-away section
          of exhaust flue
             Ladle hood
             exhaust duct
Agglomeration
furnace
  Point of air
flow measurement
                                           ^— Hood  to  ladle
                                          T   Gap 23 cm  (9 in)
                                               Slag ladle
                                       /**\    (agglomerated
                                               material)
                                                                                             Agglomerated
                                                                                               material
                                                                                                launder
                                                                  |-»- 101 cm
                                                                      (40 in)
                              (tf-
                                                                        Ladle Hood Detail
            Front Elevation - Agglomeration
            Furnace and Ladle Hood
              Figure 14.   Agglomeration furnace and ladle  hood (Hoods J and K).
                                                                                             02-4452-01

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this building by the front-end  loader is  controlled by the  routine yard
clean-up procedures.

Slag Handling—
     When slag ladles are  filled  from the SB furnace,  they  are allowed to
remain under the slag tapping hoods  (refer to Figure 13) until the slag has
cooled sufficiently to form a thick  crust.   The  ladles are  then moved by
lift truck out of the operating area to a final  cooling area shown in Figure
9.  Here the ladles cool until  the slag completely  solidifies.  Later a lift
truck dumps the slag out of the ladles in the paved yard area provided for
that purpose (refer to Figure 9).  Still  later,  a front-end loader is used
to separate the slag from  the matte  which forms  in  the very bottom of the
slag ladle.  This same front-end  loader moves the slag and  matte to separate
outdoor storage piles.

     The procedures described above  are directed at minimizing potential fume
emissions from molten slag and  dust  emissions from  handling solidified slag.
Intimate employee contact  with  slag  and matte materials is  precluded by use
of mechanized materials handling  equipment which does  not create significant
granulation of slag materials.  Wetted operating floors and yard areas help
prevent settled dust from  becoming airborne.   Some  fume emission may be
occurring from the slag ladles  at their final cooling  station.  No control
of this possible emission  source  is  present.   Employees do  not routinely
work near the cooling slag ladle.

Finished Metal Handling—
     When finished metal ladles are  filled from  the SB furnace, they are
allowed to remain under the finished metal ladle cooling hood (refer to
Figure 13) until the metal has  substantially  solidified.  Allowing the
ladles to cool under the local  exhaust ventilation  rather than in the open
air helps to reduce the fume emissions during cooling  and during any
handling of the ladle while the metal is  still molten.  The ladle is then
moved outside by forklift  truck.  Later,  the  metal  ingot is elevated from
the ladle using a forklift truck  as  a hoist.   The metal ingots are stock-
piled in the yard area until shipped or transported to refining operations.

Flue Dust Handling—
     Flue dust which collects in  the baghouse is screw conveyed to the
agglomeration furnaces.  Screw  conveyors  can  be  a potential emission source
since they tend to leak near rotating shafts,  bearings, access doors or lids,
etc.  At this smelter, settleable particulate which escapes the screw con-
veyors will fall to a paved area  below the baghouses and/or near the
agglomeration furnaces.  Here the dust would  be  wetted and  eventually flushed
into drains and sumps.  Nonsettleable particulate which escapes from the
screw conveyors would contribute  to  general ambient contamination.

     The agglomerated dust is slag-like in appearance. It  is handled by
forklift truck while contained  in slag ladles.  It  is  not permitted to
weather outside which would result in its return to a  dusty state.  Employees
are not routinely assigned to work in areas near the agglomeration furnaces.
                                      47

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Residues from Drains and Sumps—
     The paved yard surfaces and floors inside operating areas are slopped to
drains and sumps.  These water collection points are routinely cleaned to
remove deposits of mud.  Given the wetted nature of the material dust genera-
tion is not an Immediate hazard.  Splashes of particulate laden water, if al-
lowed to dry on work clothing, tools or work surfaces, could become a source
of airborne contamination.

     The deposits or residues from these sumps are recycled to the smelting
process to recover their lead content.  These materials are stored indoors
and kept wetted until charged to the smelting furnace.

Residues from Furnaces, Flues and Ductwork—
     Routine maintenance at this smelter includes cleaning dusts and
residues from flues and ductwork.  These periodic cleaning procedures create
opportunities for employee exposures.  Employees do wear respirators during
these cleanup operations, some of which take place on a weekly basis.

     When the entire SB furnace is shut down, the furnace cavity, flues,
ductwork, etc. are cleaned, inspected and repaired.  These maintenance
activities can generate emissions and the handling of residues also involves
potential exposures.  Employees are required to wear respirators during these
activities.  Furnace shutdown periods have ranged in length from a few days
to a dozen or more days depending on the extent of maintenance required.

Charging Emissions

     The depositing of material in the top of the furnace can potentially ex-
pose employees to (1) emissions from handling the charge material, and (2)
emissions from the furnace, such as flue gases which escape from the furnace
top.  Both of these emissions would emanate from Hood I shown in Figure 10.

     As stated earlier, only one employee spends any significant amount of
time in the furnace charging area.  This employee operates a front-end loader
equipped with a cab supplied with filtered air.

Slag Tapping

     Slag is tapped at each of four slag tap holes provided at the base of
the furnace.  Each of these tap holes is equipped with a short launder.  A
sketch showing the approximate location and configuration of the slag tap
holes is shown in Figure 13.

     Slag is tapped from each of the four tap holes.  Tapping involves re-
moving the tap hole plug and allowing the slag to flow down the launder
into a slag ladle.  Unique tap hole plugs are used at this smelter which
consist of a tapered wooden plug surrounded by a refractory clay (refer to
Figure 15).   This plug is placed in the tap hole and tamped tight.  A
small amount of clay is added behind the plug.  When the furnace is tapped
a bar is used to punch out the wooden core of the plug.  Once the center
is clear,  the hole can be easily enlarged by dislodging the surrounding
     portion of the plug.  This technique eliminates the need for drilling

                                     48

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                                               Wooden plug
                    • Metal  bar
                                  g
                                   • Refractory clay
                          Slag Tap Hole Plug
     Transparent window.
                                               Tuyere cap rotates
                                               for punching
                                Notch to permit
                                insertion of
                                punching bar
                          SB Furnace Tuyere
Figure 15.  Details  of  slag tap hole plug and tuyere design.
                                                        02-4453-01
                              49

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out tap holes, using sledge hammers, etc. and insures that the tap hole
perimeter will remain intact and not emit excessive quantities of furnace
gases.

     The slag tapping operation just described can be performed through an
access door in the hoods provided for slag tapping.  A slag ladle is posi-
tioned under the tap hole.  The slag tapping hood is moved into position over
the ladle and slag launder, and the tap hole plug is removed allowing the slag
to flow into the ladle.  When the ladle is filled, a new plug is installed
by feeding it through the access door in the slag tapping hood (refer to
Figure 13).  The ladle remains under the tapping hood until a substantial
crust forms.

     The movable slag tapping hoods (Hood A, B, C, D) and the secondary slag
tapping hoods (Hoods E and F) have been provided to control emissions from
slag tapping  (refer to Figure 13).  Employees do not wear respirators during
slag tapping but do utilize face shields, gloves, etc.  Slag taping is a
routine task for the furnacemen assigned to this work area.   Slag tapping is
almost a continuous operation with one of the four taps flowing slag every
ten minutes.

Tuyere Punching

     A sketch of the SB furnace tuyeres is shown in Figure 13 with a detail
of an individual tuyere shown in Figure 15.  Routine tending of the furnace
involves examination of each tuyere through the transparent window shown
Figure 15.  Periodically the tuyere cap is rotated and a steel bar is inserted
to punch out the air flow passage.  The secondary slag tapping hoods (Hood
E and F) are provided to help control any emission from the tuyere punching
activity.  Tuyere punching is a routine task for the furnacemen assigned to
this work area.  Tuyeres are examined and punched as necessary at varying
intervals throughout the workshift.

Finished Metal Tapping

     Finished metal is tapped at one end of the SB furnace as shown in Figure
13.  The molten metal is an obvious source of contaminant emission.  Exhaust
hoods have been provided for the finished metal tap hole, launder and re-
ceiving ladle (Hood G, Figure 13) and for the filled receiving ladle as it
cools (Hood H, Figure 13).

     Tapping of the furnace can be performed with Hood 6 in position over the
tap hole, launder and ladle.  One of the four furnacemen usually tends to
the finished metal tapping operation which is nearly continuous.  As the
ladles are filled and rotated under the cooling hood (Hood H) the furnaceman
swings Hood H away for a few moments so he can insert steel lifting handles
into the molten finished metal.  No control for employee exposure during this
handle insertion is provided.
                                     50

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Afterburner Slag Port

     The afterburner is  equipped with a slag port which  empties into a slag
ladle.  No control  is provided  for fume emissions which  may emanate from this
source.  The afterburner slag tap  port is located near the work area where
furnacemen prepare  the slag  tap hole plugs.   There  is a  potential for some
exposure from this  source.   In  comparison to other  emission sources in this
general work area,  the afterburner slag tapping port should be classed as a
low-order emission  source.

Agglomeration Furnaces

     The agglomeration furnaces are located outdoors in  an area not fre-
quently visited by  employees.   The flue gas streams from these agglomeration
furnaces and emissions from the slag launder and ladle can contribute to am-
bient  air contamination.  The  flue systems for these furnaces are cleaned at
weekly intervals.   The swing away  section of the flue directly above each
furnace was designed  to  facilitate this periodic cleaning (refer to Figure
14).   A local exhaust ventilation  hood is provided  for the slag ladle and
launder.  Possible  emissions from  these furnaces are not expected to signifi-
cantly contribute  to  employee  exposures on a day-to-day  basis.

Baghouse Bag Replacement

     Manual replacement  of bags during preventative maintenance or repair
work  in the four baghouses creates the potential for employee exposure.
There  is sufficient baghouse capacity at this smelter to allow shutdown
of one baghouse while  the other three remain in operation.  Workmen who
perform bag changes are  required to wear respirators.

ENGINEERING CONTROL EVALUATION

     Engineering control of employee exposure to lead and other con-
taminants at this  smelter was  evaluated using three basic sources of
information:

          Engineering measurements and design considerations

          Observations

          Air  sampling information

The sampling and  analytical techniques used are NIOSH recommended physical
and chemical analytical  methods document 173 (P&CAM 173).
                                      51

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Raw Materials Handling

Engineering Measurements—
      The engineering controls of interest to raw materials handling are:
(1) the use of sprinklers to suppress dust levels in yard areas, (2) the use
of a front-end loader with filtered air supply to handle raw materials, and
(3) the provision of a materials storage and preparation building to confine
and suppress airborne contamination associated with raw materials handling.
These controls were evaluated through observation and air sampling.

Observations—
      Yard areas were observed to be kept moist by both fixed and mobile
sprinkling units.  The floors of the Charge Storage and Preparation Building
remained wet in may areas, damp in others.  Movement of the front-end
loader within this building did not create generation of visible air-
borne dust.  The front-end loader operator remained inside the filtered
air cab except when reporting to the SB furnace control room and lavatory
area.  The doors and windows of the fron-end loader cab were kept closed.
The roll-up doors to the Charge Storage and Preparation Building were opened
and closed as necessary to allow flow of materials.  Several roll-up
doors were left open on the days evaluated.

Air Sampling—
      To evaluate the effectiveness of the raw materials handling procedures
employed at this smelter, several air samples were gathered and analyzed.
The results of this air sampling are shown in Tables 20 and 21.

      Air samples collected inside the cab of the front-end loader (Table 20,
Charge Preparation and Chargeman) indicate lead-in-air concentrations of 85
and 58 Ug/m3 on consecutive days.  The initiation of sampling on the second
day was delayed until a flat tire on the front-end loader was repaired.

      Two samples collected along the wall of the Charge Storage and Prepara-
tion Building (Table 21, Area No. 5, see also Figure 9) indicated lead-in-air
concentrations of 24 and 16 ug/m3.  Additionally, air samples gathered at
either side of the charging hood (Table 21, Area Nos. 6 and 7, see also
Figure 10) indicated lead-in-air concentrations of (79 and 71) and (65 and
85) ug/m3, respectively.  These samples reflect both the effectiveness of
dust control in the Charge Storage and Preparation Building and the effective-
ness of Hood I (Figure 10) in controlling emissions from charging and fugi-
tive flue gas emissions.

      One air sample was gathered outside near an area of materials receiving
(Table 21, Area NO. 8; see also Figure 12).  The sample indicated that the
lead-in-air concentration for the period evaluated was less than 8 ug/m3.
This sample result should not be interpreted as establishing an ambient back-
ground .
                                     52

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           TABLE 20.  BREATHING  ZONE,  LEAD-IN-AIR CONCENTRATIONS
                      ASSOCIATED WITH  SB FURNACE OPERATIONS*
                            Sampling interval
                       Lead-in-air  exposure
                       Ug/m3  during the inter-
                       val sampled	
9-26-78
  Blast furnace
    Foreman (JA)
  Furnaceman (IM)
  Furnaceman (LA)
  Furnaceman (EJ)
  Furnaceman (HP)
  Charge prep.
    & chargeman  (DA)
6:21a - 10:57a
7:34a -
6:15a -
6:18a -
6:16a -
l:33p
l:37p
l:38p
l:38p
7:03a -  l:40p
 99

 43
 57
 83
 14

 85
9-27-78
  Blast furnace
    Foreman  (JA)
  Furnaceman (MA)
  Furnaceman (CO)
  Furnaceman (MD)
  Furnaceman (BB)
  Charge prep.
    &  chargeman  (DA)
6:08a - 12:23p
6:00a -
6:03a -
6:05a -
6:17a -
l:43p
l:50p
l:44p
l:49p

l:55p
110

 35
110
 38
 79
=gge=™-^™.i»-....»e=8gBB8=g==™=g==     i "	      	
*Samples were collected on cellulose ester membrane filters with 0.8
  pore  size and were analyzed using atomic absorption spectrophotometry
  (P  &  CAM  173).
                                      53

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          TABLE 21.  WORK AREA LEAD-IN-AIR CONCENTRATIONS ASSOCIATED
                     WITH OPERATION OF THE SB FURNACE
Area no.
9-26-78
1
2
3
4
5
6
7
8
9-27-78
1 *>
2
3
4
5
6
7
8 J
a
Sampling location

Process control room
At wall near lead tapping
end of furnace
At wall near afterburner
At wall near tapping plug
preparation area
At side wall near center
of charge preparation
building
At working platform on
left side of charging
hood
A working platform on
right side of charging
hood
Near spiral stairs to
charging level

\
See location
descriptions
above



Sampling

6:24a -
6:30a -
6:43a -
6:35a -
6:56a -
6:48a -
6:50a -
—

6:00a -
6:12a -
6:33a -
6:22a -
6:36a -
6:07a -
6:07a -
6:41a -
interval

1
1
1
1
1
11
11


1
1
1
1
1
2
2
2

:50p
:50p
:50p
:51p
:55p
:30a
:30a


:55p
:45p
:58p
:58p
:55p
:00p
:00p
:00p
Lead-in-air expo-
sure ug/m3 during
the interval samp

38
23
<10
15
24
79
65
—

54
22
16
22
16
71
85
<8
*Samples were collected on cellulose ester membrane filters with 0.8y  pore
 size and analyzed by atomic absorption spectrophotometry (P & CAM 173).

       to Figures 9, 10-and 12.
                                     54

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SB Furnace Integrated Ventilation System

Engineering Measurements—
     The evaluation  of  the  integrated ventilation system (see  Figure  11)
involved measurement of air flows at several strategic  points.   It was not
feasible to make measurements  at every point of interest in  the  system.
Physical access was  the primary constraint in this regard.

     Figure 16 shows the  points at which ventilation measurements were
made. Table 22 summarizes the  hood entry coefficient measurements.  Pres-
sure and temperature measurements were made at each point indicated in
Figure 16.  However, these  measurements and the resultant flow and velocity
calculations  were considered  proprietary and are not reported here.  These
ventilation rates were  consistent with those which would be  specified using
appropriate design procedures  as outlined in the ACGIH  ventilation.  Where
appropriate, hood entry coefficients were estimated and are  presented in
Table 22.  These measurements  were made with all four baghouses  in oper-
ation.  Performance  data  concerning each of the many local exhaust hoods
was gathered and will be  presented in succeeding sections.

Observations—
     The integrated  ventilation system was observed to  be in good repair.
No serious dents or  malformations of ductwork were found. The system is
constructed of heavy gauge  steel and is provided with access openings at
strategic locations. The system is equipped with sensing devices (mainly
temperature indicators) which  relay information to the  control panel  in the
process control room.

     The SB furnace  superintendent is thoroughly familiar with the design
and performance of the  system  and routinely makes velocity traverses  in key
locations using a pitot tube and manometer.  The process is  equipped with
static pressure and  temperature sensing devices which can be monitored from
the process control  room.  The baghouses are equipped with manometers so
that bag loading, broken  bags, etc. can be detected by  operating personnel.

Air Sampling—
     The integrated  ventilation system works as a unit  to control lead-in-
air levels within the  SB  Furnace Building.  Many of the emission sources
controlled by the system  are physically close together.  Employees who work
in this building spend  varying amounts of time at different  locations.  For
these reasons the results of air sampling performed during this  evaluation
(breathing zone and  work  area) are more indicative of total  system perfor-
mance and work practices  than  of performance of individual hoods, etc.

     During the days evaluated, the roll-up doors to the ground  level oper-
ating area of the SB Furnace Building remained open much of  the  time.  Two
consecutive day shifts  were monitored.  A furnaceman crew change occurred
between the first and  second day of evaluation so possible differences in
work habits are reflected in the data gathered.
                                     55

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                                         Baghouse
                                         No.  3
               Baghouse
               No.  2
                                                 Baghouse
                                                 No.  4
Figure 16.  Key to ventilation system  test  points.
                                                                02-4454-01

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         TABLE  22.
                  SUMMARY OF HOOD ENTRY COEFFICIENTS IN SB FURNACE
                  AND AGGLOMERATION FURNACES VENTILATION SYSTEMS*
                                   0.58
             T2
                                0.56
             T3
          Tl,


          T5


          T6


          T7


          T8
                                   0.57
             Tio
                                   0.05
             TH**
                                0.76
  *Air flow measurements were made using a pitot tube and inclined manometer;
   in-duct velocities, flow rates, temperatures, and pressure data were con-
   sidered proprietary and are not reported here.
 **Calculated results
***
Cc
             ,  where SPh = hood static pressure
                                      57

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     Tables 20 and 21 contain the lead-in-air sampling data.  Breathing zone
measurements ranged from 14 to 110 yg/m3 and average 67 yg/m3 for persons
working in the SB furnace operating area.  Work area lead-in-air concentra-
tions measured in the SB furnace operating areas ranged from less than 10 to
54 yg/m3 and averaged 25 yg/m3.  It is interesting to note that the highest
work area lead-in-air concentration in the SB furnace operating area was
found in the process control room.

     A few work area air samples were also collected and analyzed for arsenic.
The results of this sampling are contained in Table 23.  No result greater
than 0.32 yg/m3 was found.

SB Furnace Charging Hood (Hood I)

Engineering Measurements—
     A sketch of Hood I is shown in Figure 10.  Figure 17 contains dimensional
information and air flow measurements.  The hood provides a minimum of 0.76
m/s (150 fpm) across its face.  An Alnor® Velometer, Jr. was used to measure
face velocity.

Observations—
     Smoke rising from the charged material inside the hood was observed to
remain within the hood.  Smoke generated at the edge of the hood and at
locations in front of the hood face (using ventilation smoke tubes)  indicated
air movement into the hood at all positions.

     Charging the furnace via the front-end loader was observed and no visible
emissions were seen to escape from the hood.

Air Sampling—
     Air samples were collected at the work platforms on either side of the
charging hood (refer to Figure 10).  The results of these measurements are
contained in Table 21 and are only partially indicative of the hood's per-
formance.  These sampling results reflected general workroom contami-
nant levels in the charging work area, as well as, possible contamination
escaping from the hood.

Slag Tapping Hoods (Hoods A, B, C, D)

Engineering Measurements—
     The SB furnace is equipped with four slag tapping hoods (Hoods A, B,
C, D).  These hoods are ducted into the integrated ventilation system as
shown in Figure 11.  These hoods work together with other exhaust ventilation
as shown in Figure 13.  The hoods are essentially identical in design.  All
are constructed from heavy metal, employ external duct fins or webs for
structural support and are made movable through use of high quality swivel
bearings.  Figure 18 provides dimensional information concerning these hoods
and air flow data.  An AlnorR Velometer was used to evaluate air flows
associated with these hoods.
                                     58

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             TABLE 23.  WORK AREA ARSENIC-IN-AIR CONCENTRATIONS
                        ASSOCIATED WITH OPERATION OF SB FURNACE*
Area no.
Sampling location'
                 Arsenic concentra-
                 tion yg/m3 during
Sampling interval  the interval
    (9/27/78)         sampled.
             At wall near lead  tapping
               end of furnace
                               6:12a -  l:45p
                      0.32
             At wall near afterburner
                               6:22a - 12:22p
                      0.15
             At working platform on
               left side of  charging
               hood
                               6:17a -  2:00p
                      0.11
*Samples were collected  on  a  cellulose ester membrane  filter with 0.8 y
 pore size and were analyzed  using  the arsenic/borohydride method.
 (Pierce, et al; Applied Spectroscopy, (30), 1976)

8Refer to Figures  2 and  4.
                                      59

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Flaps of conveyor
belt material
                                                          Face Velocity
                                                          Measurements


/

A
B


I


C
D
E
F


G
H
1
J





K
L
M
N





0
P
Q
R


S
T
U
V








W








5.48
m (18
ft)









Ft
A
B
C
D
E
F
G
H
I
J
K
L
M
N
0
P
Q
R
S
T
U
V
W
m/s
1.0
1.0
1.5
1.5
1.3
0.89
0.89
0.89
0.89
1.0
1.0
1.0
1.0
1.0
1.0
1.0
0.76
0.76
1.0
1.0
1.0
1.0
0.76
fpm
200
200
300
300
250
175
175
175
175
200
200
200
200
200
200
200
150
150
200
200
200
200
150
Figure 17.  Face velocity measurements
            (Hood I).
                                  -  furnace  charging hood
02-4455-01

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                      Swivel bearing
                     Inside diameter
                       30 cm  (12  In)
                                                             Duct fins for structural
                                                             support of hood
                   Air flow measurement
                   cross section
            Hood extention to cover
            slag tap hole and launder
Hood B
Air flow measurements
at indicated cross section

A - 0.0707 m2(.785 ft2)

Hood Entry Coefficient
  Ce s 0.57
102 cm (40 in)
(diameter)
                                                                       Swivel bearing
                                                                           Access opening for
                                                                           slag tapping
                                                                             Roller support for
                                                                             tapping bar
                                                                                      02-4456-01
            Figure 18.  Side elevation - slag tapping hoods (Hoods A,B,C,D).

-------
     Figure 19 illustrates the relationship of the slag hoods to the  slag
ladles.  Air velocities measured at the access opening and along the  gap
between the hood and ladle are indicated.  As can be seen from the data,
these hoods afford vigorous face velocities.

Observations—
     The slag tapping hoods were used by all furnacemen.  As stated earlier,
the slag tap holes at the side of the SB furnace can be opened and closed
through use of implements inserted through the access opening in the  slag
tapping hood.  Several tap hole opening and closing operations were observed.
The hoods appeared to capture virtually all smoke and fume emanating  from
the tap hole, slag launder and slag ladle.  Occasionally a heavy spark of
molten material would escape through the front access opening.

     Uniform flow into the slag hoods at all sides was confirmed through
observation of smoke generated from ventilation smoke tubes.

     Employees performing slag tapping operations always remained at  least
1  to 2 meters (3 to 6 feet) from the hoods during tapping.  Opening,  closing
and tending of the tap hole was accomplished through use of long metal rods
and other long handled implements.

     After slag ladles were filled, they were allowed to remain under the
slag tapping hoods until a substantial crust had formed on the top of the
molten slag.  During the two days evaluated, no accidental spills of  slag
occurred.  Furnacemen carefully maneuvered slag ladles using a forklift
truck.  In some instances ladles were removed with the slag tapping hood
still in position over the tap hole and launder.

Secondary Slag Tapping Hoods (Hoods E and F)

Engineering Measurements—
     The SB furnace is equipped with two secondary slag tapping hoods (Hoods
E  and F) located along either side of the furnace.  These hoods are ducted
into the integrated ventilation system as shown in Figure 11.  These  hoods
work together with other exhaust ventilation as shown in Figure 13.

     Figure 20 provides additional information concerning these hooods.  Data
concerning air flow through the exhaust plenum is included in Table 22 (Test
Point 12).  These hoods are intended to capture emissions from
slag tapping and tuyere punching operations.

Observations—
     Refer to Figure 20 for observations concerning hood performance.

Finished Metal Tapping Hood (Hood G)

Engineering Measurements—
     Hood G is provided to control emissions from the finished metal  tap hole,
launder and receiving ladle.  Hood G is ducted into the integrated ventila-
tion system as shown in Figure 11.  This hood works together with other ex-
haust ventilation as shown in Figure 13.

                                    62

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U>
        Face Velocity Measurements
             at Access Opening
             Hood B
          Ft  m/a   fpm
           1
           2
           3
           4
           5
           6
           7
           8
           9
2.4
2.2
2.2
1.9
1.8
1.8
1.8
1.8
1.8
480
430
430
380
350
350
350
350
350
                                 Face velocity at  gap
                                 1.8 - 3.0 m/s
                                 (350-600 fpm)
Hood
m/s
2.8
2.8
1.9
2.2
2.2
1.5
2.8
2.9
2.8
D
fpm
550
550
380
430
440
300
400
580
400
                                                                    Slag ladle
                                                                                        Access opening
                                                                                            Gap
                                                                                             2 to  6  cm
                                                                                             (1  to 2.5  in)
Slots for tongs from
lift truck to move
slag ladle
                                                                                                     02-4457-01
                             Figure 19.   Front elevation - slag tapping ladle (Hoods A,B,C,D).

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          Fugitive  emission
          plenum for  secondary
          slag  tapping hood
           (Hood E)
   Inlets to
/   plenum
Smelting
furnace
       Flexible
        Rubber
       Curtains

       Concrete
        column
Air Flow Measurements

Hood Entry Coefficient
      Ce = 0.56
•  Air velocities near tuyeres and
   flexible rubber curtains were less
   than 0.13 ra/s (25 fpro)

   Smoke generated inside the hood was
   observed to flow upward toward the
   exhaust plenum inlets

•  Smoke generated near the flexible
   rubber curtains indicated low order
   turbulence on back side of curtains

Note:  Details of slag ladles, slag
tapping hoods, etc. are exluded from
this figure for simplicity
                                                                                                02-4458-01
                    Figure 20.   Secondary slag tapping hoods (Hoods E and F).

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     Hood G, like the  slag  tapping hoods,  is constructed  of  heavy gauge
metal and employs external  duct  fins or webs for structural  support of the
hood (refer to Figure  21).   The  hood is made movable through use of swivel
bearings.  The bottom  edge  of  the hood is  equipped  with hanging chains to
help control any splashing  of  molten metal,  increase face velocity at the
gap between the hood and  ladle and facilitate rotation of ladles under the
hood.

     The access opening at  the hood is used  to observe and allow access to
the finished metal  tap hole.

     Figure 21 provides dimensional information for Hood  G.  Face velocity
measurements made at the  access  opening and  near the hanging chains associ-
ated with the hood  are indicated.  An Alnor® Velometer was used to make these
measurements.  As can  be  seen  from the data, Hood G provides vigorous air
flow into the hood.

     Figure 21 also contains calculated hood performance  data.  These data
and others are also presented  in Table 22  (Test Point 11).   Flow into this
hood was determined by taking  the difference in flows measured at Test Points
6 and 9 shown in Figure 16.

Observations—
     Hood G appeared to capture  all of the smoke and fumes emanating from
the finished metal  tap hole, launder and receiving  ladle. During the two
days evaluated, Hood G was  not moved from its position over  the tap hole and
launder.  Smoke generated from ventilation smoke tubes at the edges of the
hood indicated flow into  the hood at all sides.

     Occasionally a spark of molten metal  was observed to escape from the
front access opening.   This usually occurred when the tap hole and launder
were being cleaned  through  use of a long metal rod  inserted  through the
access door.

Finished Metal Ladle Cooling Hood (Hood H)

Engineering Measurements—
     Hood H is provided to  control emissions from molten  metal contained in
a receiving ladle which has  recently been  filled.   Hood H is ducted into the
integrated ventilation system  as shown in  Figure 11.  This hood works to-
gether with other exhaust ventilation as shown in Figure  13.  Hood H like
Hoods A, B, C, D, and  G is  constructed of  heavy gauge metal and employs ex-
ternal duct fins or webs  for structural support of  the hood  (refef to Figure
22).  The hood is made movable through use of  swivel bearings.  The bottom
edge of the hood is equipped with hanging  chains to help  improve face veloci-
ty and facilitate rotation of  ladles under this hood.

     As indicated in Figure  22,  Hood H is  a  slotted hood.  The slot evenly
distributes the capture zone around the perimeter of the  ladle.  Air flow
information gathered using a pitot tube and  inclined manometer at Test Point
T9 (see Figures 16 and 22)  is  presented in Table 22 and in Figure 22.
                                      65

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Air flow measurements

  Face velocity at gap
    Near chains 1.5 m/s  (300 fpm)
    At front of hood in  space with
     no chains 2.5 m/s (500 fpm)
  Face velocity at access opening
                                                       Swivel bearing
                                          Duct fins for structural
                                          support of hood
                                                                          Swivel bearing
A


B
C E


D F
(•« — 40.6 cm — v
t
22.9 cm
(9 in)

10
              (16 in)
Pt
A
B
C
D
E
F
m/s
2.3
2.4
2.0
1.7
1.8
1.3
fpm
450
480
400
340
350
250
           71 cm
                •
          (28 in)


10 cm (4 in) gap -
                                   81 cm (32 in)—
                                                      Inside diameter
                                                      31.5 cm (12.4 in)
                                                                               Access opening for
                                                                               finished metal tapping

                                                                                  Hood lower diam.
                                                                                  142 cm (56 in)
                                                Chains

                                             Finished metal ladle
                                             (top diameter 127 cm
                                             50 in)

                                             Finished metal
                                             ladle carrousel
                                                                                               02-4459-01
              Figure 21.  Front elevation of finished metal  tapping hood (Hood G).

-------
                       Swivel bearing
                                Duct fins for
                                structural support
                                of hood
              Inside diameter
              19.7 cm (7.75 in)
    15.2 cm (6 in)
    hood depth


10 cm (4 in) gap'

        Finished metal
        ladle carrousel
       Damper

      Expansion Takeoff

           Flange
        Finished
<      metal ladle
                               Hood Entry Coefficient
                                 Ce - 0.65

                               Air flow measurement
                                 V -   = 19.3 m/s  (3800  fpm)
                                  slot
                                                         Hood radius
                                                         71  cm  (28  in)
                                                          12 mm  (5/16 in)
                                                                slot
                                                 Radius to slot
                                                 56 cm (22 in)
                   Side elevation of finished
                   metal  ladle cooling hood
                                 Detail of slot design
                                      inside head
                                                                                               02-4460-01
                        Figure 22.  Finished metal ladle cooling hood  (Hood H).

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Additionally, slot velocities and face velocities measured with an Alnor®
Velometer are included in Figure 22.

Observations—
     Ventilation smoke tubes were used to generate visible smoke at the edge
of this hood.  The smoke was observed to flow into the hood at all locations
around its circumference.

     Hood H was swung away from over the cooling ladle to allow insertion of
handles into the molten metal.  This operation required only a few moments to
complete but did require the furnaceman to lean over the ladle containing
cooling molten metal.  The employee did not wear a respirator when perform-
ing this task which occurred a few times each shift.

Agglomeration Furnace Ladle Hood (Hoods J and K)

Engineering Measurements—
     Hoods J and K are ducted into the integrated exhaust ventilation system
as shown in Figure 11.  Dimensional information and proximity to the agglom-
eration furnaces is shown in Figure 14.  Also included in Figure 14 is an
estimate of the air flow through these hoods.

     Face velocity measurements were precluded by significant ambient air
currents present on the days evaluated.  Hi-vol area sampling near the ag-
glomeration furnaces detected 12 and 18 yg Pb/m3 on the test days (see
Table 10, Section 4).

Observations—
     The gap between the slag ladle and hood is quite large (refer to Figure
14).  Smoke generated under and near the hood using ventilation smoke tubes
was not effectively captured by the hood.  Ambient air currents overpowered
the influence of the hood and allowed generated smoke to escape.

OTHER INDUSTRIAL HYGIENE CONSIDERATIONS

Employee Work Schedules

     The SB furnace operates continuously.  Five teams of employees man
three shifts of work.  Each employee works an average of 36 hours per week.

Personal Protective Equipment

     Clean trousers, shirts and work jackets are furnished each week to
employees.  Employees provide and wash their own underwear.  Use of gloves,
safety helmets and safety glasses is optional.  Employees wear safety-toe
footwear and utilize faceshields during slag tapping.  Respirators are re-
quired to be worn during furnace clean-up or repair, baghouse maintenance,
and during routine flue and duct cleaning.  The charge preparation operator
does not normally wear a respirator.  He may elect to wear one during hand-
ling of particularly dusty materials which are occasionally received by the
smelter.
                                     68

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Employee Hygiene

     Employees are instructed to shower at the conclusion of each shift  and
to wash before eating.  Locker room, shower and lunchroom facilties pro-
vided at this smelter are not elaborate.  Employees are permitted to smoke
and consume beverages in the SB furnace process control room.  It was
observed that employees did not wash their hands each time they used
smoking materials or consumed beverages in this area.

Biological Monitoring

     Urine specimen collection and analysis is not performed.  Blood samples
are obtained from operating employees each month and from other employees on
a quarterly basis.  The results of blood lead monitoring are reported to
employees and the employees have access to all of their blood lead analysis
results.  The employee is informed that his result is acceptable (less than
70 ug Pb/lOOg whole blood), marginal (71-90 ug Pb/lOOg whole blood) or
unacceptable (90+ ug Pb/lOOg whole blood).  The employee is also informed
whether the result shows a strong increase, increase, no change, decrease
or strong decrease in blood lead level since the last test.  Exhibit A con-
tains the blood lead monitoring data for employees assigned to the SB fur-
nace which were made available to this evaluation.

Workplace Air Monitoring

     Reportedly, many workplace lead-in-air measurements were made shortly
after the SB furnace was made operational.  Three to four months prior to
this evaluation smelter personnel made their most recent breathing zone  and
work area measurements.  The results of these measurements were not requested
for inclusion in this evaluation.

Noise Level Measurements

     A sound level survey was made of the operations associated with the SB
furnace.  The results of this survey are shown in Table 24.  As can be seen
from data, no serious noise sources were discovered.

CONTROL CRITIQUE

     The engineering and work practice controls of employee exposure at  this
smelter are exemplary.  The effectiveness of this system of controls is  evi-
denced by the control of employee exposures to lead in all work activities
associated with the SB furnace to approximately 100 ug/m  or less.

     In general, the local exhaust ventilation systems provided for the  SB
furnace are well designed and maintained.  They provide good enclosure of
emission sources, vigorous hood face and duct transport vel 'cities,^ access

                                                            i
                            =S5.
 from other 5 furnace work areas provides obvious benefit In confining
                                      69

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              TABLE 24.  RESULTS OF NOISE MEASUREMENTS MADE IN
                         ASSOCIATION WITH SB FURNACE OPERATIONS
Location no.
1*

2*

3*
Description of measurement
location and/or operation
2 meters from burner end of
afterburner
2.5 meters from side of
afterburner
Slag tapping location, after-
Noise
type1
S/I
S

s

S
Sound '
Expo s ure2 level 3
C/I
I

I

I
dBA
78-80

81-83

81-82
dBC
88-90

91-94

87-88
   4*

   5*


   6*


   7*

   8


  10


  11
burner side of furnace, metal
tapping end of furnace

Near finished metal ladles       S

Slag tapping location, control   S
room side of furnace

1 meter from afterburner end     S
of furnace

Process control room             S

Charging level, right side       S
of charging hood

Charging level, near combustion  S
air fan for afterburner

Inside cab of charge prepara-    S
tion front-end loader
I

I
I

I
 75

74-75
55-57

79-81


92-94


80-88
84-85

84-86
     77-78   89-90
69-71

84-87


94-96


88-98
*Refer to Figure 1 for location of sound level measurement

1JJoise type:  S = steady, I = Impulse or impact

2Exposure: C = continuous, I » intermittent

3Sound level:  Measured in decibles on the A and C weighting networks of a
               type S2A sound level meter
                                     70

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contamination generated  by these operations to the Charge Storage and
Preparation Building.  The low lead-in-air concentrations found  in  this build-
ing must be at least  in  part attributable to the handling of  agglomerated flue
dust rather than bulk quantities of untreated flue dust.

     Yard sprinling and  washdown procedures appear to minimize entrainment of
dust into the air, tracking of muddy materials into other work areas, and
splashing of mud on employee clothing and plant equipment.

     Washdown procedures employed in the SB furnace operating area  did main-
tain floors in dust free and clean conditions.  Washdown  operations were
timed so that slag was tapped into ladles and then floors were washed.  By
the time slag was to  be  tapped again the floor covered by metal  plates at
the slag tapping station was essentially dry.  According  to operating per-
sonnel, the presence  of  wetted floors near molten metal and slag handling
has not resulted in increased hazard when molten metal or slag spills have
occurred.

     A few situations were discovered which could be improved.   They are:

      •    The SB furnace process control room was found to be contaminated
          with lead  (38  to 54 yg/m3) .  Since employees are permitted to
           smoke  and consume beverages in this area, it is recommended that
          improved ventilation and housekeeping be provided to reduce lead
          contamination.  It is unknown to what extent the contamination
          of this control room together with smoking and  beverage consump-
           tion and other hygiene practices contribute to  employee lead ab-
          sorption as evidenced by reported blood lead levels.

          Ventilation of the control room could be engineered to bring in
          outside air through filters and maintain the control at a slight
          positive pressure with regard to the SB furnace operating floor.
          In any future  installations of this type, consideration should be
          given  to  enlarging the control room and arranging control panels
          so that the base of the SB furnace could be viewed  through windows
          in the control room wall.  This would reduce traffic in
          and out of  the control room when simple observations or hand sig-
          nals to employees are required.

          The insertion  of metal handles into molten finished metal at the
          finished metal ladle cooling station currently  creates some uncon-
          trolled exposure to the employee performing this operation.  Ex-
          posure occurs  when the employee must lean over  the  ladle  to insert
          the handles and hold them until frozen in place.  Possibly a set of
          tongs or other such tool could be used to reach over the  ladle and
          insert the  handles preventing the employee from being  directly ex-
          posed.

          Limitations of the study did not permit careful evaluation of the
          effectiveness  of the air filtration system provided for the cab of
          one front-end  loader.  If this filtration system is indeed
                                      71

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effective, its installation on all similar yard equipment
used at this smelter should be considered.

The local exhaust hoods provided for the slag ladles at the
agglomeration furnaces could be made more effective by reducing
the gap between the ladle and hood and also reducing the velocity
of cross drafts caused by wind.  It is suggested that a concrete
pad or other substantial stand be provided to elevate ladles
closer to the hoods.  The bottom of the hood could be fitted with
hanging chains to help break up cross draft air movement.
                          72

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                                   SECTION 6

                         OTHER PROCESSES AND CONTROLS
     In addition  to  the  SB furnace and associated equipment, a variety of
other smelting  processes are operated at the Paul Bergs^e  and Sons A/S
Glostrup, Denmark facilities.  Two of these processes:  (1)  rotary furnace
smelting, and  (2)  pot  induction furnace smelting were evaluated during
this study.  Each of these processes received relatively less attention
than the SB  furnace.  The primary aim of the evaluations of these processes
was to describe control  equipment which may be readily  adaptable to similar
processes in the  United  States.

ROTARY FURNACE  SMELTING

Description  of  Equipment and Controls

     Rotary  furnace  smelting operations are conducted in separate facilities.
Figure 23 shows a large  building which is divided into  two major sections.
One part of  the building is devoted to furnace operations  while the other
part contains charge storage and preparation functions.

Receipt of Raw  Materials—
     A variety  of  raw  materials (slags,  drosses,  etc.)  are  received for
smelting in  the rotary furnaces.   These materials are unloaded from trucks
and stored in the  segregated bins in the Charge Storage and Preparation Build-
ing shown in Figures 4 and 23.   The yard unloading area is  sprinkled and
washed down  in  similar fashion  to that described  for  the SB furnace facili-
ties.  Materials are handled by a variety of front-end  loaders.

Charge Storage  and Preparation—
     The Charge Storage  and Preparation Building  associated with the rotary
furnaces (refer to Figure 23) is a concrete structure provided with a large
roll-up, materials delivery door, twelve bins for segregating raw materials,
and another  roll-up  door which  communicates with  the  rotary furnace operat-
ing area.  This building is equipped with an automatic  sprinkling system
which periodically wets  floors  and dampens piles  of raw materials.  Several
bins containing bagged,  relatively non-toxic materials  are  not sprinkled.
No mechanical ventilation is provided for this  building.
                                      73

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           Charge
           material
           storage
           bins
                Charging and
                tapping hood
  Charge storage and
  preparation building
                                                                      . Refractory
                                                                     / storage
                                  «___J
                                  Brick flue
                     Welding
                     shop
                               ^V    (Stockpiled   *
                               J 1    |finished metalj

                               '  \   "	
door and
charge container
resting deck
                                                   Rotary
                                                   furnace
                                                   building









Locker
room

Control
room
(D
i©
I
i
furnace
  oooooooo
  Slag crucibles (cooling)
                                                                          Refractory storage
                                                                          and preparation
                                                          crucible '
                                                          storage QOO
                                                        ^
                                                                            1	'  Lllir
                                                                Roll-up
                                                                Door
                                                            Roll-up door
              OArea air monitoring
              location
                                                                                         Scale:
O              Location of noise
              measurement
                                                                                           6 meters
Figure 23.   Rotary furnace  smelting and  charge  storage preparation building.
                                                                                             02-4461-01

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Rotary -furnace Charging  Equipment—
     Charge materials  for  the rotary furnace are placed in specially
designed charge containers which rest on a low platform behind  the roll-up
door between the  furnace operating and charge preparation section of the
building.  Figure 23 shows the location of this charge container resting
platform.  Figure 24 shows a close up of the charge resting platform and a
detail of an individual  charge container.

     Each rotary  furnace is equipped with a round charging door in the
center of the front end  of the furnace (refer to Figure 25).  The lift truck
picks up the charge container from one end, inserts it into the furnace,
and then rotates  the container to dump the charge material.  Rotation is
accomplished through use of a rotating lift head on the lift truck.

     After dumping, each container is rotated back to  its upright orientation,
removed from the  furnace and replaced on the charge container resting deck.
When all containers have been emptied into the furnace the roll-up door at
the resting deck  is closed.

     An exhaust hood is  provided at the front of the furnace to capture emis-
sions from the  furnace during charging.  A sketch of this hood  is shown in
Figure 25.  Exhaust draft  to this hood is controlled by a damper located
directly behind the hood.

Rotary Furnace Operating Controls—
     The two rotary furnaces studied are tangentially  fired from the rear.
Hot combustion  gases enter the furnace body, circulate to the front of the
furnace and then  are exhausted through the brick flue  (Refer to Figure 23
and 25) .  The furnaces are of steel shell construction with refractory
lining.  They rotate 360°  and the rotation can be reversed.

     Figure 25 shows the exhaust ventilation controls  for the rotary furnaces.
Hot flue gases are exhausted through the brick flue.  The gap between the
furnace body and  the brick flue is enclosed and exhaust ventilated.  An
arched hood is  provided over the charging/tapping end  of the furnace.  Exhaust
draft to this hood is  controlled by an electrically operated damper.  The
damper is opened  during charging and tapping.  The two furnaces are operated
on staggered 10 hour cycles which allows the exhaust draft to be directed
from one furnace  to the other during alternating charging and tapping
operations.  The  retractable portions of the arched hood open to allow an
overhead crane  to pickup filled ladles and replace empty ladles.

     Each furnace is provided with a ladle cooling hood.  After tapping ladles
filled with finished metal are set beside the furnace  at a location where
a ladle can be swung over  them to capture emissions during cooling.  (Refer
to Figures 23 and 25.
                                      75

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                                  Concrete  floor
                                  and wall
                                                                                     Roll-up door
                                                                             Resting deck
                                                        Detail  of charge  container
                                                                                               02-4462-01

Figure 24.  Close-up of charge container resting deck, roll-up door, and  detail  of  charge container.

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                    Electrically
                    Operated
                    Damper
Retractable
arch hood
enclosures
            Finished
           metal ladle
Brick flue
                                                                  Hood enclosing
                                                                  furnace to flue
                                                                  connection
                                                            Wide slot exhaust
                                                            pickups
                                                 168 cm (5 ft 6 in)
          Figure 25.  Rotary  furnace  charging and tapping controls.
                                                                       02-4463-01
                                      77

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     No mechanical dilution or makeup air ventilation  is  supplied  to  the
rotary furnace operating area.  Natural ventilation  is facilitated by open-
ings in the roof and along each of  the side walls of the  building.  Air  also
enters through the large roll-up doors which are frequently open.

     Air drawn into the rotary furnace local exhaust ventilation hoods and
into the hot  gas flue  is combined and passed through a baghouse before
being release to the ambient environment.  Flue dust is collected  in  fabric
cubical containers and recycled to  the rotary furnaces.   At the time  this
evaluation was performed, flue dust from the rotary  furnaces was not  being
agglomerated.

     The floors of the rotary furnace operating area are  routinely  flushed
with water.   The water drains into  central sumps which are periodically
cleaned to remove sludge or mud.

     Employees do not  routinely wear respirators while working in  the  rotary
furnace operating area.  Respirators are worn in the rotary furnace Charge
Storage and Preparation Building, when handling flue dust and when working
with storage  piles in  the yard area surrounding the  rotary furnace building.

     A process control room is provided in the rotary  furnace operating area.
This room  contains process control  panels and is also  used as a rest area
where employees are permitted to smoke and consume beverages.

Description of Emission Sources and Potential Exposures

Materials  Handling Emissions—
     In this  portion of the smelter there are several  situations where
employees  can be exposed to contaminants emitted by  materials handling.  The
following  paragraphs describe these situations, the  employee interaction
with the emission source and the control of the source.

Raw Materials Handling—Off loading and handling of  raw materials  can  involve
generation of airborne contamination.  In this portion of the smelter  flue
dust is handled in unagglomerated form which creates significant exposure.
A number of yard or general labor personnel handle materials at this  smelter.
The smelting  site is crowded with many piles of stored material lining
traffic-ways.  As necessary employees bring material into the rotary  furnace
Charge Storage and Preparation Building.  These employees frequently wear
respiratory protection especially when handling dusty  materials.   Generation
of  dust in this building is suppressed by the sprinkling  and washdown  con-
trols described earlier.

     Since the rotary  furnaces are operated on a batch rather than  continuous
production schedule, charge preparation and handling is not a full  time
activity.   Filling of  charge containers can be accomplished in several
minutes using a front-end loader.  During this operation, employees are  in-
structed to wear respirators.  Aside from delivery of  charge materials and
                                    78

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charge container filling no  other activities are conducted  in  this portion of
the building.  Therefore,  total employee exposure time in this area is only a
few hours each day.                                                       3

Slag Handling—When  slag is  tapped into ladles from the rotary furnaces  the
ladles remain briefly  under  the arched exhaust hoods.   They are then moved
by lift truck to the indoor  slag cooling area shown in Figure  23.  Any fume
or smoke emitted from  these  slag ladles escapes into the work  environment.
No local exhaust ventilation is provided for the cooling slag  ladles.  Em-
ployees do not wear  respirators during slag handling.   After the slag has
solidifed, portions  of it  may be removed from the ladles at the cooling area
or the ladles may be taken outside and dumped.   A large front-end loader is
used to handle dumped  slag.   Wetted floors and yard surfaces are the only
controls which assist  in suppressing potential particulate  emissions from
solidified slag handling.

Finished Metal Handling—When finished metal ladles are filled from the
rotary furnaces they are moved from under the arched hood to cooling stations
between the furnaces.   Local exhaust hoods are then swung over the ladles to
capture emissions during cooling.   Emissions from the  ladles during transfer
to the cooling station are uncontrolled.   Employees do not  wear respirators
when handling finished metal ladles.

Flue Dust Handling—Exposure to flue dusts collected from rotary furnace
operations occurs during baghouse maintenance,  flue dust container (fabric
cubical) replacement and handling,  and during charge prepartion.  Aside from
wetted and washed down working surfaces,  respirators are the primary means to
control employee exposure  to flue dust.

Residues from Drains and Sumps—The paved yard surfaces and floors inside
operating and materials handling areas are sloped to drains and sumps.
These water collection points are routinely cleaned to remove  deposits of
mud.  Given the wetted nature of the material,  dust generation is not an
immediate hazard.  Splashes  of particulate laden water,  if  allowed to dry
on work clothing, tools or work surfaces,  could become a source of airborne
contamination.

Residues from Furnaces, Flues and Ductwork—During furnace  shutdown the
rotary furnace and flue retractory is inspected,  repaired and/or replaced.
These operations create opportunities for employee exposure.   Employees do
wear respirators during maintenance operations.

Charging Emissions—                                              .
      Rotary furnace charging is performed by one furnaceman operating a lift
 truck.  Rotation of the furnace is stopped, the draft to the  arched exhaust
 hood is activated,  the front access charging door of  the furnace Is opened,
 the roll-up door at the charge container resting deck is raised, and charge
 containers are emptied one  by one into the furnace.
                                      79

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     Emissions from the charging operation emanate from the furnace  charging
door and rise into the arched hood.  If the charge container is not  completely
righted before being withdrawn from the furnace, buoyant fumes and smoke
can be trapped under the inverted container and released when the container
is righted.  If the container is righted outside the influence of the
arched hood, these emissions escape into the workplace.

     Only the furnaceman who operates the lift truck is directly involved
with furnace charging.  He is not directly exposed to charging contamination
which emanates from the charging door.  He can be exposed to fugitive
emissions which escape the arched hoods or which are entrained by the charge
containers as they are withdrawn from the furnace.  Charging requires less
than 30 minutes to complete and may involve 10 to 15 tons of material.
The furnaceman performing this operation does not wear a respirator.

Slag and Metal Tapping—
     When the furnace is ready to tap, its rotation is stopped, the  draft to
the arched hood is activated and a rolling work platform is positioned under
the arched hood.  The furnace rotation is stopped at a point where one of the
three tap holes is positioned above the fill level in the furnace but within
easy reach of a furnaceman when standing on the rolling work platform.  A sledge
hammer is used to loosen a metal rod with a flat head which is lodged in
the center of the taphole refractory plug.  This rod is removed when loosened.
The furnaceman who performs the tapping operation then wears a faceshield
while using a pneumatic hammer and bit to clean out the refractory material
from the taphole.  This tapping operation takes several minutes during which
time the furnaceman is close to the end of the furnace where he is exposed
to radiant heat, noise from the pneumatic hammer, and potentially to emis-
sions from the tap hole refractory and furnace interior which escape from
the taphole.  A respirator is not worn during this operation.

     Once the taphole has been opened the rolling work platform is moved away
and a slag ladle is positioned under the arched hood using a lift truck.  From
a position outside and adjacent to the process control room, a furnace man
operates the controls which govern furnace rotation.  A second furnaceman
stands a few meters from the slag ladle to observe the filling of the
ladle.  The furnace is rotated and slag is poured.  When the ladle is nearly
full the furnace is rotated to stop the flow of slag.  A lift truck  removes
the filled slag ladle from under the arched hood and deposits it at  the slag
ladle cooling area shown in Figure 23.  An empty slag ladle is then  moved
into position.

     Emissions from the tap hole rise into the arched hood.  Emissions from
cooling slag ladles escape into the work environment.  Employees do  not wear
respirators during this operation.

     Finished metal is tapped after slag.  The same taphole is used  for both
metal and slag tapping.  An overhead crane is utilized to move finished metal
ladles.   The overhead crane is operated by a pendant control.  The movable
sections of the arched hood are retracted to allow the cables from the over-
head crane to pass and close positioning of the ladle.  When a ladle is filled
                                     80

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it is manually skimmed using  a long handled hoe like  instrument.  The crane
is then used to move  the  filled ladle to its cooling  station where a local
exhaust ventilation hood  is provided.

     Emissions during metal pouring rise into the  arched hood.  Emissions
from the ladle during its transfer to the cooling  station escape into the
workplace.  Employees do  not  wear respiratory protection when pouring and
handling finished molten  metal.

     Once the finished metal  has frozen in the ladle,  the crane is used to
remove the metal ingot and transfer it to the stockpile area shown in
Figure 23.

     The furnace taphole  is closed using refractory mud/clay and the central
metal rod.

Engineering Control Evaluation

     The engineering  controls of employee exposure to  lead and antimony
associated with rotary furnace operation were evaluated using three sources
of information.  They are:

     •    Engineering measurements and design considerations

     •    Observations

     •    Air sampling information

     These information sources will be discussed where applicable in conjunc-
tion with the control evaluated.

Charge Materials Receiving, Storage and Preparation—
Engineering Measurements—The engineering controls of  interest are: 1) the
use of sprinklers to  suppress dust levels in yard  areas and inside the Charge
Storage and Preparation Building,  and 2)  the separation of these activities
from rotary furnace operations.   These controls were evaluated through ob-
servation and air sampling.

Observations—The floors  of the Charge Storage and Preparation Building were
observed to remain wet.   Storage piles in bins were moistened.  Movement of
the front-end loaders within  this building does not create visible generation
of airborne dust.  The roll-up doors to the Charge Storage and Preparation
Building were opened  and  closed as necessary to allow  flow of materials.

Air Sampling—To obtain some  limited information concerning the effectiveness
of charge materials storage and handling controls, air samples were collected
at two inside locations near  the roll-up doors to  the  Charge Storage and
Preparation Building.  The results of this air sampling are shown in Table
25.  Lead-in-air concentrations of 120 and 220 Pg/m3,  and antimony-in-air
concentration of less than 17 UgM3 and 15 yg/m3 were  measured.  These values
are not high considering  the  fact that flue dust is handled in this area.
                                     81

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   TABLE 25.  LEAD AND ANTIMONY-IN-AIR CONCENTRATIONS ASSOCIATED WITH ROTARY
              FURNACE OPERATIONS*

                          Sampling          Lead-in-air   Antimony-in-air
  Job/location**          interval          cone, yg/m3     cone. pg/m3.


 Breathing Zone - Samples

 Furnaceman (HL)          6:06a - ll:lla       290          <24
 Furnaceman (HL)          ll:lla- l:45p        180          <47
 Furnaceman (EJ)          6:04a - ll:15a       180          <16
 Furnaceman (EJ)          ll:15a- l:45p        180          <47
 Furnaceman (SJ)          6:04a - ll:10a       170           33
 Furnaceman (SJ)          ll:10a- l:45p        130          <36
 Yardman (NN)             6:06a - l:48p        200          <14

 Area Samples - Rotary Furnace Operating Area

 Rotary Furnace           6:07a - 2:05p         42           16
   Control Room(l)
 Outside Control          6:10a - ll:12a        86          <23
   Near Center of
   Furnace Area(2)        ll:12a- l:56p         59          <46
 Between Rotary
   Furnace, Near          6:02a - ll:14a        97           17
   Firing End of
   Left Furnace(3)        ll:14a- l:56p         32           42

 Area Samples - Charge Storage and Preparation Building

 Charge Preparation
   Building Near          6:20a - 2:00p        120           17
   Door to Yard(4)
 Charge Preparation
   Building Near          6:16a - 2:00p        220           15
   Door to Furnace
   Area(5)
 *
   Samples were collected on cellulose acetate membrane filters with 0.8y pore
   size and analyzed atomic absorption spectrophotometry (P & CAM 173)

** Refer to Figure 23 for location of area sampling stations.
                                     82

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Rotary Furnace Exhaust Ventilation Controls—
Engineering Measurement—The exhaust ventilation  system is schematically
depicted in Figure 26.  Evaluation of this system involved measurement of
air flows at  several strategic points in the system.  As with all ventila-
tion systems  of this general type, it was not feasible to make measurements
at every point of interest in the system.  Physical access was the primary
restraint in  this regard.

     Figure 26 shows the points at which ventilation measurements were made.
Where appropriate, hood entry coefficients were estimated and are presented
in Table 26.  Performance data concerning the arched hood and ladle cooling
hood are presented in succeeding sections.

Observations—The rotary furnace exhaust ventilation system was found to be
in good repair.  No serious dents or malformations  in ductwork were found.
The system is constructed of heavy  gauge steel.

     During the  day this system was evaluated, problems were encountered with
the baghouse bag cleaning mechanism.  A portion of  the baghouse jammed  in
the cleaning cycle mode which resulted in significantly reduced draft to the
furnaces while repairs were made.   Emissions were observed to escape from
the arched hoods during  this period.  These emissions visibly contaminated
the rotary furnace operating area for over an hour.

     The day prior to process evaluation, the electric damper behind the
arched hood on one of the rotary furnaces broken  down and required repair.
During the repair period significant  quantities of  air contamination escaped
 into  the workplace.   Also during this workday a major spill of finished
metal  occurred when  the  receiving ladle was accidentally overfilled.  The
metal spilled out  onto a wetted floor which caused  generation of  copious
 quantities of steam but  no  serious splashes or projection of hot  metal
 occurred.

      Handling of flue dust  in fabric  cubical containers appeared  to involve
 significant  exposure to  flue  dust.   Connection of the collecting  containers
 to the hoppers of the baghouse was not  dust tight.


^Sffi^-sss.'sss n»= =£- -
                          ~ •   
-------
Furnace to flue
gap hood
Electric
damper
    Ladle
cooling hoods
                                                      .11      	J
                                                             Prime air mover
                                    Furnace
                                    to flue
                                    gap hood
Electric
damper
                         Charging and tapping hoods
                                                              02-4464-01
        Figure 26.  Overview of rotary furnace ventilation controls
                    and key to ventilation system test points.
                                    84

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     TABLE  26.   RESULTS OF TESTS IN ROTARY FURNACE VENTILATION  SYSTEM*

                           Hood entry coefficient Ce**

                  TI                    0.58
                  T2
                  T3
 *Air  flow measurements were made using a pitot tube and inclined manometer;
  in-duct  velocities, flow rates, temperature, and pressure data were con-
  sidered  proprietary and are not reported.

**      /vp
  Ce = W "cF~ > where SPt, = hood  static pressure
       If SPh           h
                                      85

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     Two air samples were gathered from each employee's breathing zone and at
each location in the rotary furnace operating area.  The baghouse malfunction
occurred during the 6:00 a.m. to 11:00 a.m. work period.  Measured air con-
tamination was generally more significant during this period.

     As can be seen from the data, employee exposures to lead-in-air were
found to range from 130 to 290 yg/m3 on the day evaluated.  Only one
quantifiable employee exposure to antimony was measured (33 yg/m ).  Other
samples contained less than the detectable limit of antimony.  Work area
samples showed lead-in-air concentrations ranging from 32 to 97 yg/m .
Measurable concentrations of antimony ranged from 16 to 42 yg/m3.  Relatively
higher contaminant concentrations were found in employee breathing zones as
compared to work area samples.  This suggests that employees are exposed to
contaminant sources during their work activities.  Exposure involves contami-
nant concentrations which are higher than the background workroom contamina-
tion.

Rotary Furnace Charging and Tapping Hood—
Engineering Measurements—Figure 25 presents a sketch of the rotary furnace
charging and tapping hood.  The hood consists of a stationary section and two
retractable arch sections which function in conjunction with crane operation.
Air is exhausted from this hood through wide slots which are distributed
over the front side of the arch in the stationary portion of the hood.
These slots are approximately 10 cm (4 in.) in width.  An Alnor® Velometer
was utilized to measure air velocities at the lowest three slots on each
side of the arch.  Radiant heat and physical access prevented measure-
ments at all slot openings.  Slot velocities ranging from 3.3 to 7.6 m/s
(650 to 1500 fpm) were measured with lowest velocities found at the bottom
slots.

     Physical access problems precluded measurement of air flow and static
pressure in the ductwork directly behind the electrically operated damper.
An air flow measurement was made at point TZ shown in Figure 26.  Air flow
at this point is the sum of air entering the arched charging and tapping
hood and air entering the hood enclosing the furnace to brick flue
connection.  It is estimated that approximately 6 m3/s (13,000 cfm) enters
through the arched charging and tapping hood.

Observations—A complete charging of each furnace was observed.  Emissions
which emanated from the charging door were observed to rise into the arched
hood and enter the exhaust slots.  A relatively small amount of contamination
was observed to escape from the top front of the hood.  Wisps of smoke and
fume were also observed to escape from the small gap between the retractable
and stationary sections of the arched hood.  These emissions rose into the
workplace and were diluted.

     During insertion and extraction of charge containers through the
furnace charging door, varying amounts of* contamination were observed to
escape from the arched hood.  Most of the escaping contamination appeared to
be entrained by the charge containers.  This problem was most significant
when charge containers were not completely righted before extraction from
the furnace.

                                     86

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     Several iterations of  tapping both slag and  metal were observed.  Slag
tapping requires  several  minutes to complete and was observed  to  involve
between six and twelve slag ladles.  Emissions from the  tap hole  anlslag
ladle were observed to rise into the arched hood and be  collected.  Only
minor amounts of  fume were observed to escape into the workplace during
pouring of slag into ladles.

     A crust was  observed to form on the slag almost immediately.  However,
visible fume/smoke was observed to emanate from each slag ladle as it was
moved by  forklift to the  cooling area.   While cooling smaller  and smaller
amounts of emission were  observed to escape from the ladles for several
minutes.

     During slag  tapping, one furnaceman operates the furnace  rotation
controls, one moves  slag  ladles with a  lift truck,  and a third observes
ladle filling and signals the man controlling furnace rotation.  Aside from
walking by cooling ladles of slag,  these men were not observed to be
directly exposed  to  emissions from slag tapping.   While slag is poured from
the furnace, these men observe from a distance of several meters.

     Finished metal tapping produces seemingly larger quantities of fume.
This fume emanates from the tap hole and ladle as it is filled.  The
arched hoods were observed  to capture practically all of the metal tapping
emissions when metal was  poured at a less than maximum rate.  When the
furnace was rotated to produce very rapid pouring,  a relatively small but
seemingly important  quantity of fume was observed to escape capture by the
arched hood.

     Some direct  exposure of employees  to fumes from molten metal was
observed during the skimming of the metal and during its movement to the
cooling station using the overhead crane.  Both of these operations are
conducted with employees working within three meters of the ladle.  This
proximity provides the opportunity for  exposure to fumes which are being
entrained by room air currents.   Another similar  exposure was observed when
the crane hooks were removed at the ladle cooling spot and the exhaust hood
was swung over the ladle.

     When the retractable arches of the charging/tapping hood are raised,
fumes emanating from the  filled ladle of metal are not completely captured
by the stationary portion of the hood.   Fume emission at this time is not
vigorous, but escaping fumes,  etc.  do contribute  to background contamination.

Rotary Furnace Ladle Cooling Hood--                            _
Engineering Measurements—Figure 27 presents a sketch of one finished metal
ladle cooling hood used in  the rotary furnace operating area.  Hood dimen-
sional and performance data are contained in Figure 27 and Table 26.  As can
be seen from the  figure,  this is a slotted hood which spreads  the capture
zone around the perimeter of the ladle.
                                      87

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       Duct fins for
       structural
       support of hood
oo
oo
                                Swivel bearing
Inside diameter
19.7 cm (7.75 in)
D                                        Finished
                                        letal ladle
                                                                      Hood  Entry Coefficient
                                                                        Ce  - 0.58    N
                                         Air flow measurements
                                               (at chains) = 0.51-1.3 mps
                                                             (100-250 fpm)
                                                                       face
slot
                                                 5.1-10 mps (1000-2000 fpm)
                                                                                                 Hood radius
                                                                                               80 cm (31.5 in)
                                                                                       Radius to slot
                                                                                      64.8 cm (25.5 in)
                    Side elevation of finished
                    metal ladle cooling hood
                                    Detail of slot design inside hood
                                                                                                     02-4465-01
                                 Figure 27.   Finished metal ladle cooling hood.

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Obseryations-Once  the  hood was  positioned over  a  ladle of cooling metal, no
emissions were observed to escape capture by  the hood.  Smoke generated by
Ihf i  H ?h Smt6^  KS St the Perimeter of the  ^od was observed to flow into
the hood through the  hanging  chains.

Hood Enclosing the  Furnace to Flue Connection—
     No quantitative  evaluation  of this  hood  could be made.  It does enclose
the gap between the furnace and  flue  as  shown in Figures 25 and 26, and no
emissions were observed to escape this hood.

Other Industrial Hygiene Considerations

Personal Protective Equipment—
     Similar protective clothing and  equipment policies as described for SB
furnace operations  are  followed  in the rotary furnace work area.

Employee Hygiene—
     See discussion associated with SB furnace operations.

Biologic Monitoring—
     No results of  blood lead monitoring were obtained for employees working
in the rotary  furnace department.  Refer to the  discussion associated with
the SB furnace for  a  description of biologic  monitoring policies.

Noise Level Measurements—
     A sound level  survey was made of the operations associated with the
rotary furnaces.  The results of this survey  are shown in Table 27.  As can
be seen from the  data,  no serious noise  sources  were discovered.

Control Critique

     The engineering  controls provided for rotary  furnace operations are
well designed  and maintained. When functioning  properly and used appropri-
ately by employees, these controls capture the vast majority of emissions
which are  produced  during charging, furnace operations, tapping and
finished metal cooling.

     Several opportunities  remain for improvement  of fugitive emission
control.   These opportunities have been  eluded to  in the past and
primarily  involve work practices and operational changes.  Emissions from
cooling slag ladles could be  reduced by  placing  covers over the ladles or
relocating the cooling area out-of-doors.  Emissions from metal tapping
could be reduced  by pouring  the  metal more slowly  from the furnace into the
ladle.  Additional  emission control could be  accomplished by allowing the
finished metal ladles to remain  under the arched hoods for a longer period
before moving  to  the  final  cooling station.

     Housekeeping in  the rotary  furnace  work  area  was good.  Frequent wash-
down of floors appeared to significantly reduce  potential entrainment of
settled particulate into workplace air.
                                      89

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           TABLE 27.   RESULTS OF NOISE MEASUREMENTS MADE IN ASSOCIATION WITH ROTARY FURNACE OPERATIONS
vo
o
Location
no.*
1
2
3
4
5
Description of measurement Noise type1
location and/or operation S/I
Between rotary furnaces
Burner end of rotary furnace
Near rotary furnace combustion
air fan
Pouring end of rotary furnace
Beside rotary furnace next to
Charge Storage and Prepara-
tion Building
S
S
S
S
S
Exposure2
C/I
I
I
I
I
I
Sound
dba
77
82
85-86
77-78
81
level3
dbc
84-86
89
92-93
83-84
86
           *Refer to Figure 23 for location of sound level measurement.



           1Noise type:   S = Steady,  I = Impulse or Impact.



           2Exposure:  C = Continuous, I = Intermittent.



           3Sound level:  Measured in decibles on the A and C weighting networks

                          of a Type 52A sound level meter.

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     Employees should  be instructed to wear respirators  during  and following
periods of process  upset,  failure of ventilation controls  or  during spills?


POT INDUCTION FURNACE

     A variety of small furnaces are used to produce relatively minor quan-
tztles of specialty alloys at this smelter.   The ventilation  controls associ-
ated with one, small,  tilting electric induction furnace proved to be
interesting and  are discussed here.

Description of Equipment and Controls

     The furnace studied is used to produce specialty copper  based alloys.
An overview of this furnace and its associated exhaust ventilation hood are
shown in Figure  28.

     This furnace is located in a building with several  other furnaces en-
gaged in production of various alloys.  The furnace  is of  tilting type which
facilitates pouring of its molten contents into a transfer ladle.

     The furnace is provided with a slotted hood suspended over the furnace;
this hood can be moved so that emissions from the furnace  in  its level and
tilted position  can be controlled.

Description of Emission Sources and Potential Exposures

     Fumes and smoke emanate from the top of the induction furnace during
furnace charging, meltdown and pouring.  Due to its  small  size  the furnace is
manually charged.   Containers of scrap (mostly plant scrap) are dumped into
the furnace.  In some  instances a scoop shovel is used to  handle fine materi-
als.  Ingots of  known  composition may also be added  to bring  the melt to
proper specification.

     During  charging the furnaceman can effectively  add  materials to the
furnace without  being directly exposed to the plume  of emissions emanating
from the  furnace.  This can be accomplished by moving the  hood  to various
positions  over  the furnace to allow the necessary access.  Initial charging
usually will require only several minutes to complete.  As the  material
melts additional materials may be added at varying intervals.

     While  the  furnace charge is melting, the furnaceman tends  to other
operations located in the same building.  This employee  returns to the furnace
periodically to  observe how the melt  is preceding.

     As  the  melt nears readiness  for pouring, the furnace  man skims the molten
metal surface and moves the transfer  ladle into position to  receive the»lt«u
alloy.  Again the overhead slot hood  can be manuevered to  prevent  the employee
from being directly exposed to the plume of fumes emanating  from the furnace.
                                      91

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       Rectangular  duct
       Height:  40.6 cm (16 in)
       Width:   51 cm (20 in)
                Air flow measurements
                SP • -132 mm HjO
                  (-5.2 in H20)
      Stiffeners
            102 cm
            (40 in)
                                             Swivel bearing connection
                                             to exhaust ductwork
            Square bar stock for
            structural support
            of ductwork and hood
              Hood Entry Coefficient
                Ce -  0.63
                                                                Swivel  bearing
Tilting furnace housing
(housing lifts on  this
end to pour contents
of furnace)
                                                                  10 slot exhaust pickups
                                                                  2 cm (0.75  In) in width
                                                                    slot
                                                                           5-20 raps
                                                                   (1000-3900  fpm)
                                                                 Pot furnace
                          Fold over
                         furnace lid
    Direction of
    housing tilt


Hood width:   178 cm (70 in)

Hood depth:   170 cm (67 in)
(front to back)
                                                                              02-4466-01
                  Figure 28.   Pot  induction  furnace hood.
                                          92

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     During pouring of  the  furnace,  the furnace  and  its housing deck tilt as is
indicated in Figure 28.  The  overhead exhaust  hood is moved to allow this tilt-
ing but still remain  in position to  capture emissions.  Once the molten metal
is poured into the transfer ladle, the ladle is  moved out from under the hood.
No control is provided  for  emissions from the  ladle  until it reaches its pour-
ing station.  The employee  who  tends this furnace is exposed to fugitive emis-
sions from this  furnace operation and to fugitive contaminants from other
equipment in the same general work area.

Engineering Control Evaluation

Engineering Measurements—
     The pot induction  furnace  hood  was evaluated by measuring slot velocity
inside the hood  and air flow  in the  duct leading away from the hood.  Slot
velocity measurements were  made using an Alnor®  Velometer.  A pitot tube and
manometer were used to  make air flow measurements at the point indicated in
Figure 28.

     As indicated by  the  results of  the measurements, a large volume of air
is moved through this hood  resulting in relatively high slot velocities.

Observations—
     When positioned  over the pot furnace, the hood  appeared to very effec-
tively capture all visible  contamination. •

     During charging, skimming and pouring the furnaceman did not always take
full advantage of  the mobility of the hood to  help preclude his contact
with emissions.  Better hood  positioning could have  been possible during the
period observed.

     Ventilation smoke tubes  were used to observe air flow at all sides of the
hood.  Smoke was observed to  be swiftly pulled into  the hood.

Air Sampling—
     Due  to  the  presence of multiple emission sources in the same general work
area,  air  samples  were not gathered in the evaluation of this hood.

Control Critique

     The hood  appeared to function well when properly utilized by the furnace-
man.   Emissions  from the transfer ladle as it is moved  to casting lines could
be lessened by placing a lid over the ladle.  This would also help  to reduce
 the possibility for splashes of molten metal to occur.
                                       93

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                         APPENDIX


BLOOD/LEAD DATA  SUPPLIED BY BERGS0E MANAGEMENT
                                      6th October, 1978
                                      NG/aju
                                      3-170/20
  Radian Corporation
  8500 Shoal Creek Blvd.
  Austin, Texas 78756
  U.S.A.

  Att.: MX. Richard Coleman
  Dear Rick,

  As agreed during your visit here last week, we shall provide
  statistical information  about the blood-lead measurements on
  our personnel working in the SB furnace department.

  Regular lead-in-blood measurements have only been made over
  the last two years,  and  they have not been consistent at all
  times.  For this reason  we prefer to give you only the most
  recent figures,  i.e.  the lead-in-blood result of the latest
  sample drawn from each of the 27 employees up to mid Septem-
  ber 1973.  They  all  date from the latest few months.

  The SB furnace has been  in operation for about 3 years, and
  most of the people have  only worked in that department.  Three
  men have been transferred from other departments less than a
  year ago, but no one later than January 1978.


  Lead-in-blood figures for period .up to week 78/37
  (dated 17th September 1978)

  ^kg/100 ml   No. of  persons, and working history (Note 11

   i 30        4,  worked less than 6, months  (Note 21
   31-40       1,  worked about 1 year
   41-50       5,  worked 1% - 2 years
   51-60       7,  worked 2-8 years
   61-70       8,  worked 1^-4 years (Notes 3 and 4)
   71-80       2,  worked 2 and 3 years respectively

   Total      27 persons
                             94

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                                     6th October, 1978
                                     page 2
Radian Corporation
Richard Coleman
Note 1.  All samples wera analysed by a O.K. laboratory
(NOSH).  Recent interealibrations with other laboratories
strongly indicate that the results from NOSH are significantly
higher than those of the official Danish work Safety Labora-
tory  (AMT).  The statistical difference is no less than 29%,
and if it were deducted it would bring the above figures
below  60 *g.

Note 2.  Tests taken upon employment.

Note 3.  One man in this group worked 21 years  in the plant.

   	4.  One of these tests was crosschecked with three other
   'Oratories, all finding 10-15 -g less.
Note 4
labors-
                                      Yours  sincerely,
                                      PAUL BERGS0E  1  S0N A/S
                                      Niels  Gram
                          95

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                                    TECHNICAL REPORT DATA
                             (Please read Instructions on the reverse before completing)
  REPORT NO.

   EPA-600/2-80-022
                                                             3. RECIPIENT'S ACCESSION-NO.
 4. TITLE AND SUBTITLE

 Evaluation of Paul Bergsoe & Son Secondary Lead Smelter
              5. REPORT DATE
               January  1980 issuing  date
              6. PERFORMING ORGANIZATION CODE
 7. AUTHOR(S)

  Richard T. Coleman &  Robert Vandervort
                                                            8. PERFORMING ORGANIZATION REPORT NO,
 9. PERFORMING ORGANIZATION NAME AND ADDRESS
                                                             10. PROGRAM ELEMENT NO.
 Radian Corporation
 8500 Shoal Creek Blvd.
 Austin, Texas   78766
              11. CONTRACT/GRANT NO.
              IAG# EPA-78-D-X0309

              NIQSH Contract  #210-77-0008
 12. SPONSORING AGENCY NAME AND ADDRESS
  Industrial Environmental Research Laboratory
  Office of Research  and Development
  U.  S.  Environmental Protection Agency
  Cincinnati, OH   45268
              13. TYPE OF REPORT AND PERIOD COVERED
              Final: 10/78-10/79	
              14. SPONSORING AGENCY CODE
                   EPA/600/12
 15. SUPPLEMENTARY NOTES
 16. ABSTRACT
       This report  presents the findings  of an investigation performed to obtain data
  concerning fugitive  and workroom emissions from secondary  lead smelters.   The results
  are being used within both NIOSH and  EPA as part of a  larger effort to define the
  potential workplace/environmental impact of emissions  from this industry  segment and
  the need for improved controls.  The  findings will also be useful to other agencies
  and the industry  in  dealing with control problems.  Either the Metals and Inorganic
  Chemicals Branch  of  the USEPA or the  Division of Physical  Science and Engineering of
  NIOSH should be contacted for any additional information desired concerning this
  program.
 7.
                                 KEY WORDS AND DOCUMENT ANALYSIS
                   DESCRIPTORS
b.lDENTIFIERS/OPEN ENDED TERMS  C.  COSATI Field/Group
 Secondary Lead Smelting
 Lead
 Fugitive  Lead Emissions
 Occupational Exposure
Bergsoe Agglomeration
  Furnace
Fugitive Lead Emission
  Controls
 8. DISTRIBUTION STATEMENT
  RELEASE TO PUBLIC
                                               19. SECURITY CLASS (ThisReport)
                                                 Unclassified
                            21. NO. OF PAGES
                              110
SO. SECURITY CLASS (Thispage)
  Unclassified
                                                                          22. PRICE
EPA Form 2220-1 (9-73)
                                              96
                                                                    U.S. GOVERNMENT PRINTING OFFICE: 1980-657-146/5597

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