United States
Environmental Protection
Agency
Office of Air Quality
Planning and Standards
Research Triangle Park NC 27711
EPA-450/3-79-015
March 1979
Air
v>EPA
A Review of Standards
of Performance for New
Stationary Sources -
Secondary Lead Smelters
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EPA-450/3-79-015
A Review of Standards
of Performance for New
Stationary Sources -
Secondary Lead Smelters
by
John W. Watson and Kathyrn J. Brooks
Metrek Division of The MITRE Corporation
1820 Dolley Madison Blvd.
McLean, Virginia 22102
Contract No. 68-02-2526
EPA Project Officer: Thomas Bibb
Prepared for
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Air, Noise, and Radiation
Office of Air Quality Planning and Standards
Research Triangle Park, North Carolina 27711
March 1979
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This report has been reviewed by the Emission Standards and Engineering
Division, Office of Air Quality Planning and Standards, Office of Air, Noise
and Radiation, Environmental Protection Agency, and approved for publica-
tion . Mention of company or product names does not constitute endorsement
by EPA. Copies are available free of charge to Federal employees, current
contractors and grantees, and non-profit organizations - as supplies permit
from the Library Services Office, MD-35, Environmental Protection Agency,
Research Triangle Park, NC 27711; or may be obtained, for a fee, from the
National Technical Information Service, 5285 Port Royal Road, Springfield,
VA 22161.
Publication No. EPA-450/3-79-015
11
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TABLE OF CONTENTS
LIST OF ILLUSTRATIONS vi
LIST OF TABLES vii
1.0 EXECUTIVE SUMMARY 1-1
1.1 Scope of Standards 1-1
1.2 Overview of Secondary Lead Industry 1-1
1.3 Control Technology 1-3
1.3.1 Source of Emissions 1-3
1.3.2 Types of Control 1-3
1.3.3 Results of Controls 1-4
1.3.4 Costs of Controls 1-5
1.4 Test Results 1-6
1.5 Industry Trends 1-6
1.6 Possible Changes: Analysis, Conclusions and
Recommendations 1-7
1.6.1 Current NSPS 1-7
1.6.2 Standards for Lead Emissions 1-7
1.6.3 Investigation of Standards for S02 1-8
2.0 INTRODUCTION 2-1
3.0 CURRENT STANDARDS FOR SECONDARY LEAD SMELTERS 3-1
3.1 Affected Facilities 3-1
3.2 Pollutants Controlled and Emission Levels 3-1
3.3 Performance Test 3-2
3.4 Definitions Applicable to Secondary Lead Smelters 3-2
3.5 Regulatory Basis for Any Waivers, Exemptions, or
Other Tolerances 3-4
4.0 STATUS OF CONTROL TECHNOLOGY 4-1
4.1 Scope of Industrial Operations 4-1
4.1.1 Production of Secondary Lead 4-1
4.1.2 Geographic Distribution 4-7
4.1.3 Plants Subject to NSPS 4-7
4.2 Production of Secondary Lead 4-9
4.2.1 Reverberatory Furnace Operation 4-9
iii
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TABLE OF CONTENTS
(Continued)
4.2.2 Blast Furnace Operation 4-12
4.2.3 Pot Furnace Operation 4-14
4.3 Pollutant Emissions 4-15
4.4 Applicable Controls 4-20
4.4.1 Methods and Effectiveness 4-20
4.4.2 Cost to Industry , 4-37
4.5 Energy and Other Resource Requirements 4-39
4.6 Environmental Effects of NSPS 4-43
4.6.1 Estimated Particulate Reduction 4-43
4.6.2 Estimated Reduction in Lead Emissions 4-44
5.0 INDICATIONS FROM TEST RESULTS 5-1
5.1 Test Coverage in Regions 5-1
5.2 Test Data 5-3
6.0 ANALYSIS OF POSSIBLE REVISIONS TO NSPS 6-1
6.1 Industry Trends 6-1
6.2 Review of Current NSPS 6-3
6.3 Lead 6-4
6.3.1 Emission Rates 6-4
6.3.2 Control Effectiveness 6-5
6.3.3 Fugitive Emissions 6-8
6.4 Sulfur Dioxide 6-13
6.4.1 Emission Rates 6-13
6.4.2 Resulting S02 Concentrations 6-17
6.4.3 Control Technology 6-19
6.4.4 Potential Impacts for S02 NSPS 6-31
7.0 CONCLUSIONS 7-1
7.1 Retention of Current NSPS 7-1
7.2 No Specific NSPS for Lead Emissions 7-3
7.3 Study of Fugitive Emissions 7-4
7.4 Investigation of NSPS for S02 Emissions 7-5
iv
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TABLE OF CONTENTS
(concluded)
8.0 RECOMMENDATIONS
8.1 Current NSPS for Particulates and Opacity 8-1
8.2 Comprehensive Data on Lead Content of Emissions 8-1
8.3 Fugitive Emissions 8-1
8.4 NSPS for S02 Emissions 8-2
9.0 REFERENCES 9-1
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LIST OF ILLUSTRATIONS
Figure Number Page
4-1 U.S. Secondary Lead Production 4-4
4-2 Secondary Lead Smelters 4-8
4-3 Lead Reverberatory Furnace 4-10
4-4 Process Flow Sketch of Lead Blast Furnace
or Cupola with Cooling System 4-13
4-5 Controlled Lead Pot and Ventilation System
with Baghouse 4-16
4-6 Comparison of Allowable Emissions for
Particulates (50 to 50,000 Ib/hr) vs.
Process Weight for NSPS and State
Implementation Plans 4-23
4-7 Efficiencies Required to Meet NSPS for
Particulates as Function of Uncontrolled
Emission Rates 4-25
4-8 Capital Costs of a Fabric Filter Control
System for Blast and Reverberatory Furnaces
as Functions of Flow Rates 4-29
4-9 Horsepower Requirements for Venturi Scrubber
as a Function of Fan Efficiency and
Pressure Drop 4-41
4-10 Fuel Requirement for Venturi Scrubbers 4-42
6-1 Maximum Ground-Level Concentration of Lead
Particles in Air and Distance from Stack 6-9
6-2 Uncontrolled S02 Emissions 6-16
6-3 Maximum S02 Concentrations as a Function
of Emissions 6-18
6-4 S02 Emissions at Selected Control Levels 6-28
VI
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LIST OF TABLES
Table Number Page
4-1 Consumption of Scrap Lead in the U.S. 4-2
4-2 Estimated Production of Secondary Lead 4-6
4-3 Secondary Lead Smelters Estimated
Uncontrolled Emission Rates (Ib/ton charge) 4-18
4-4 Estimated Particulate Control Efficiency
for Equipment Used with Secondary Lead
Furnaces 4-26
4-5 Comparison of Cost Estimates for Control
of Secondary Lead Smelters - Fabric Filter
System (dollars) 4-31
4-6 Comparison of Cost Estimates for Control of
Secondary Lead Smelters with Venturi
Scrubbers ($ thousands) 4-33
4-7 Estimated Costs of Control (Annualized
Basis)(1978 dollars/ton of lead) 4-36
4-8 Estimated Annual Reduction of Particulates
From NSPS 4-43
4-9 Estimated Total Reductions in Lead Emissions
From NSPS 4-46
5-1 MITRE/Metrek Survey of NSPS Test Data From
Regions II and IV 5-2
6-1 Estimated Total SCL Emission in 1985 From
Selected Source Categories 6-14
6-2 Estimated Costs of SC^ Control per Ton
Captured 6-29
6-3 Estimated Reductions in Total Annual SC>2
Emissions from Future NSPS 6-32
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1.0 EXECUTIVE SUMMARY
This report reviews current New Source Performance Standards
(NSPS) for secondary lead smelters and analyzes possible revisions.
It provides background information to be used by the U.S. Environ-
mental Protection Agency in assessing the need for possible revision
of the NSPS.
1.1 Scope of Standards
Currently the NSPS for secondary lead smelters applies to par-
ticulate emissions and opacity. Particulate levels are set at 50
mg/dscm* (0.022 gr/dscf**) for blast and reverberatory furnaces.
Opacity of emissions from these furnaces may be no greater than 20
percent. Pot furnaces with capacity exceeding 550 tons are subject
to standards for opacity only, which is set at a maximum of 10
percent.
1.2 Overview of Secondary Lead Industry
Secondary lead produced by smelting of scrap accounts for rough-
ly half of all lead produced in the U.S. After a record output of
over 626,000 tons in 1976, secondary lead output declined in 1977 to
between 588,000 and 600,000 tons (Bureau of Mines, 1978). Used vehi-
cular batteries typically account for some 60 percent of all lead
scrap recycled annually at secondary smelters. Storage batteries for
vehicles and other uses accounted for more than half of the total
U.S. demand for lead (primary and secondary combined) in 1976. The
*Milligrams per dry standard cubic meter.
**Grains per dry standard cubic foot.
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transportation sector is expected to consume a larger share of total
output by the year 2000. Major consumption of lead for construction
and electrical purposes, paints and pigments is also expected to
continue. Attrition of the tetraethyl lead market for gasoline
additives and a continuing shift to other materials for such purposes
as pipes, caulking, cable sheathing and interior paints are expected
to reduce the rate of, but not prevent, increase in lead demand over
the next 20 to 25 years. On the average, output of secondary lead
has increased by about 1.4 percent annually since 1955.
The secondary lead industry is characterized by a high degree of
concentration in that a few companies dominate the market. The trend
is towards fewer and larger plants. Total number of smelters de-
creased from 160 in 1967 to about 115 in 1975. Overall, the average
annual output per smelter is in the range of 5700 to 6000 tons. Geo-
graphically, the industry is somewhat dispersed; secondary lead
smelters are located in all of the 10 EPA regions.
Best estimates are that on the average two new plants and from
one to two modified smelters will become subject to NSPS each year
(EPA, 1973; Bureau of Mines, 1978). EPA projection of a typical
secondary smelter with a 50 ton/day capacity and a flow rate of
15,000 scfm has been used as the basis for many of the calculations
in this report.
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1.3 Control Technology
1.3.1 Source of Emissions
Operating blast and reverberatory furnaces emit particulate
matter from the stacks. EPA has estimated average rates of
uncontrolled particulates emitted to be about 147 Ib/ton of metal
charged to a reverberatory furnace and about 193 Ib/ton for a blast
furnace. On the basis of about 70 percent recovery of metal, these
rates exceed 200 Ib of particulates/ton of lead product. Average
emission rates of S02 per ton of lead product are estimated to be
about 76 Ib and 114 Ib for blast and reverberatory furnaces, respec-
tively (EPA, 1975). Pot furnaces, which are used in secondary
smelters only to remelt and purify or alloy the product of a blast or
reverberatory furnace, emit particulates and S0£ at a rate which
was indicated as negligible by EPA (1975). The particulate emissions
from secondary lead furnaces have a lead content estimated at 23
percent (EPA, 1977). Their capture is, therefore, important for
environmental protection and is also advantageous to plant operation
because the fines recovered can be recycled in further lead
processing.
1.3.2 Types of Control
For collection of particulates, fabric filters and high-energy
wet collectors of the variable-throat (venturi) type are effective in
enabling secondary lead smelters to meet the NSPS. A baghouse or
venturi scrubber may be employed alone or in combination with
auxiliary devices in secondary lead furnaces.
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Efficiencies well above 99 percent are typically required of
control systems to meet particulate standards imposed on secondary
lead smelters. Inlet particulate loadings from about 3 up to 12
gr/dscf of gas may be presented to collectors from a representative
furnace requiring efficiencies of over 99.5 percent.
1.3.3 Results of Controls
The reduction in particulate emissions from establishment of the
NSPS is estimated to be about 1000 tons each year from those plants
newly subject to the standards (i.e., plants built, modified or
reconstructed during that year). While this is a small reduction in
comparison with the total estimated particulate emissions for the
U.S. of 16 million tons (in the year 1976), the lead content of the
particles makes their capture environmentally important. Since
future plants may be twice the size of the present average, a
reduction in particulate emissions of twice the above value may occur
in the next few years. Possible adverse environmental effects and
resource consumption have been relatively small. EPA (1973)
estimated negligible solid waste disposal requirements because of
recycling of captured particulate matter. Incremental energy
requirements for fabric filter controls are insignificant because of
very nominal pressure drop (4 inches of water gauge) through the
baghouse. The very high pressure drops (30 to 100 inches water
gauge) required with high-energy scrubbers increase horsepower
requirements and result in additional fuel consumption estimated as
the equivalent of about 1000 barrels of oil per plant annually. The
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total additional energy consumption each year would depend on the
number and production rate of new and modified plants coming in line
which used high-energy venturi scrubbers. Since no more than four
new and modified plants are estimated in any one year, the increment
would represent much less than 1 percent of the average daily import
to the U.S. of more than 7 million barrels for the year 1976 (Bureau
of Mines, 1976).
1.3.4 Costs of Controls
Costs of control have been high to operators of secondary lead
smelters that come under NSPS. EPA has estimated costs for 50 ton/
day model blast and reverberatory furnaces equipped with baghouses
(fabric filters) and with venturi scrubbers. Capital costs for
control of such a blast furnance using fabric filters are estimated
(EPA, 1977) to be on the order of $1.24 million and about $470,000
for a reverberatory furnace (in 1976 dollars). These costs have also
been estimated on an annualized basis, representing amortization of
capital outlays and expenditures for operation and maintenance. In
terras of the value of the lead product, yearly control costs are
estimated to be on an overall average about $78/ton for a blast fur-
nace and $9/ton for a reverberatory furnance. These amounts repre-
sent, respectively, about 14.6 and slightly less than 2 percent of
the average value of the lead product (based on an average price per
ton of lead of about $535). Venturi scrubbers are estimated to
involve capital costs of about $895,000 for blast furnaces and
$669,000 for reverberatory furnaces (EPA, 1978). The resulting
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annualized costs represent, respectively, about $33 and $22 per ton
of lead product, or about 6 and 4 percent of product value.
1.4 Test Results
Information on only four tests of secondary lead smelters was
available to the study. In these results for blast, reverberatory
and pot furnaces, particulate emissions were 0.0135, 0.015 and 0.0013
gr/dscf, respectively, compared with the current NSPS level of 0.022
gr/dscf. Opacity readings were less than the maximum allowable per-
centage. This sample is too small to be considered as adding any-
thing to the results reported by EPA (1973) at the time of preparing
the NSPS.
1.5 Industry Trends
The concentration of the secondary lead production in the hands
of a few large companies which dominate the market is expected to
continue. Despite shifts in demand patterns and attrition of the
major tetraethyl lead market, consumption of all lead (primary and
secondary) is expected to grow at an average rate of nearly 2 per-
cent/year from 1976 to 2000.
A trend in the lead industry, both secondary and primary, which
has been under way since at least the mid-fifties has been a decrease
in the real price of the metal product. In other words, although the
sales price of lead per ton has increased, in terms of constant dol-
lars (i.e., relative to overall inflation), the value has declined.
Despite occasional oscillations, the price has decreased about 27
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percent since 1954 (Bureau of Mines, 1977). Thus, the industry is
faced simultaneously with decreasing net income margins and with the
need for expensive capital outlays for control equipment.
1.6 Possible Changes: Analysis, Conclusions and Recommendations
1.6.1 Current NSPS
Available data indicate that no change is warranted in current
NSPS for particulates and opacity from secondary lead smelters.
Additional data are needed to investigate the:
• Extent of fugitive, emissions from secondary lead plants
subject to NSPS control.
• Present state of control technology applicable to both
fugitive and stack emissions. In regard to the latter, the
type of control equipment seen as reflecting best current
technology does not seem to have changed since the NSPS were
promulgated. However, more information on capabilities under
a range of representative operating parameters of both the
devices themselves and the furnaces is needed as a basis for
considering whether the level of control technology has
significantly advanced.
1.6.2 Standards for Lead Emissions
No NSPS which would set levels specifically for lead emissions
from secondary smelters are warranted at this time because best
technological control systems for particulates also represent BACT for
lead which is required by current standards for particulates. Avail-
able evidence indicates that control systems trap at least as high a
percentage of lead-bearing particles as were emitted by the furnace
(23 percent) and, hence, that no useful purpose would be served by
developing new standards for lead emissions which would be redundant
to those already promulgated for particulate control. Furthermore,
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two standards applicable to the same particulate control system would
cause potential administrative and enforcement difficulties.
However, the information on lead emissions from secondary lead
smelters is not totally comprehensive so that it is not now possible
to eliminate all doubt on the issue* One recent study suggested a
higher percentage of lead in stack emissions. To confirm the
conclusions which are implied by currently available data, a compre-
hensive analysis of the matter is warranted. It is recommended that
additional data should be collected under field and laboratory condi-
tions and analyzed to determine the disposition of the lead-bearing
particles of various sizes emitted from the furnace. A materials
balance should resolve the issue, based on comparison of the size
distribution of lead particles from baghouse catches with those emit-
ted from the furnace (inlet loading to the control system) and those
trapped in the output from the control system.
1.6.3 Investigation of Standards for S(>2
Total S02 emissions from all secondary lead smelters are not
excessive on the present uncontrolled basis when compared with the
overall output of other industries. Nor are the ground-level concen-
trations of S(>2 at the point of maximum concentration predicted to
occur from secondary smelters of typical size under average meteoro-
logical conditions high, relative to ambient standards. However, the
rates of uncontrolled emissions of S02 per ton of lead product from
secondary smelters seem somewhat high per ton of product when com-
pared with those for other industries and with rates for sources
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controlled under NSPS. Emission rates of SC>2 per ton of secondary
lead product are on the average about twice those from regenerative
furnaces used in filter glass manufacture and they compare with
uncontrolled rates for sulfuric acid plants on a per ton of product
basis.
It appears that the BACh? could potentially reduce SO emissions
from secondary lead smelters by about 80 to 90 percent of uncon-
trolled rates. Such a reduction would represent technology transfer
from control methods used elsewhere, particularly in control of large
fossil fuel fired boilers in utilities and other industrial plants.
Limited information available from manufacturers of control equipment
indicates that the most efficient and economic means consist of a wet
collector system that uses an alkaline reagent to neutralize sulfur
oxides in the stack gas while simultaneously scrubbing out particu-
lates.
Although the potential for technology transfer looks promising,
the economic aspects require a much more detailed analysis than is
possible from information currently available. Based on available
data, best estimates currently possible of the capital costs for a
combined system are from 10 to 20 percent higher than costs for a
venturi scrubber designed to control particulate emissions only
(although an increase in costs by as much as one-third cannot be
ruled out). On an annualized basis the additional increment would
appear to represent less than 5 percent of the average value of a ton
of lead product and is probably in the range of 2 to 3 percent.
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Annualized cost estimates per ton of SC>2 removed are about $115 for
a reverberatory furnace and $235 for a blast furnace.
The ability of the secondary lead industry to afford these
increased costs is also an issue that warrants close investigation.
At present, the potential impact on the industry is very difficult to
assess because of the proprietary nature of information regarding
industry costs and earnings and because of the limited manufacturers'
data on costs of control systems. The demand for lead appears rela-
tively inelastic so that cost increases in the range of 5 percent or
less would probably be passed along to the consumer without signifi-
cant effect on the average net income for the industry as a whole.
It is problematic whether small companies requiring new plants or
modification might be so adversely affected by even slight cost
increases as to accelerate the existing trend towards concentration
of production within the industry in a few large companies. There is
also the question of competition between new plants faced with
increased expenditures for SC>2 control and older plants able to
operate without such costs.
In view of all of the uncertainties, it is concluded that the
question of NSPS for S02 emissions from secondary lead smelters
should be investigated. Consideration of a possible standard is
based on two principal factors: (1) the state of SC>2 control
technology that appears applicable to secondary lead furnaces, and
(2) the relatively high rate of uncontrolled emissions of S02 that
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is estimated to occur from these plants. It is recommended that the
following investigations be undertaken:
• Comprehensive data on emission rates of SC>2 from plants
now controlled under current NSPS should be assembled and
analyzed to assess the need for a regulatory standard.
Information now available reflects the general estimates of
AP-42 and a few pre-1974 test results which are inconclusive
and show a wide range.
• More comprehensive and detailed surveys should be made of
manufacturer capabilities and costs involved in supplying
combined systems for SC>2 and particulate removal, with
particular reference to plant smelters of different size
and operating conditions and to the needs of smaller plants
(under 50 ton/day capacity).
• Achieved efficiencies for such combined systems should be
determined in terms of S02 reduction and particulate
removal, and the relationship of efficiency to cost should
be assessed.
• The probable economic impacts of a regulatory standard on
the secondary lead industry should be thoroughly assessed in
terms of its ability to afford SC>2 controls. Issues to
address would include the ability to pass on costs and the
effects on the competitive position of smaller plants and of
new plants vs. existing ones.
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2.0 INTRODUCTION
The Clean Air Act of 1977 requires that the NSPS be reviewed
every 4 years. The levels of performance achievable under best
available control technology are compared with existing NSPS.
Estimated energy needs, environmental effects produced by emission
controls and potential effects on industrial operations are also
considered.
Results of testing emissions from secondary lead smelters under
NSPS are examined. Only four results were available from tests
conducted for EPA regions and state agencies.
Possible revisions to the standards are analyzed with particu-
lar attention given to changes in acceptable emission levels, addi-
tions to the pollutants controlled, and process facilities regulated.
The probable effects of changes in standards and/or associated regula-
tions are considered with respect to the environment and industry.
Specific recommendations are made regarding standards and unresolved
issues are addressed.
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3.0 CURRENT STANDARDS FOR SECONDARY LEAD SMELTERS
New Source Performance Standards were adopted on March 8, 1974,
which specified allowable levels of emissions from several industrial
sources, including secondary lead smelters (40 CFR 60). Any secondary
lead smelter under construction, modification, or reconstruction on or
after June 11, 1973, became subject to NSPS. The NSPS for secondary
lead smelters were revised April 17, 1974 and October 6, 1975.
3.1 Affected Facilities
Facilities in a secondary lead smelter that are subject to NSPS
are reverberatory furnaces (stationary, rotating, rocking, or tilt-
ing), blast (cupola) furnaces, and pot furnaces of more than 550-lb
charging capacity (EPA, 1977). Furnaces for smelting lead alloy for
newspaper linotype are subject to the standards if they meet the same
size requirement as applied to pot furnaces. Also affected by NSPS
are modified secondary lead smelters (a physical or operational change
that increases the emission rate of any pollutant) and reconstructed
secondary lead smelters in which the replacement cost of components
exceeds 50 percent of the cost of building a comparable new facility.
3.2 Pollutants Controlled and Emission Levels
Particulate emissions from secondary lead smelters are subject to
regulatory control. Approximately 7 percent of a charge from such a
smelter is lost or released in the forms of fumes and particulate
matter: smoke, dirt, limestone, coke dust, fuel bits, and metal
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oxides—specifically oxides (or sulfides) of lead (EPA, 1977). As
stated in 40 CFR 60, no owner or operator of a secondary lead smelter
under construction on or after June 11, 1973 shall discharge or cause
the discharge into the atmosphere from any affected facility any gases
which:
• Contain particulate matter in excess of 50 mg/dscm (0.022 gr/
dscf).
• Exhibit 20 percent opacity or greater; or 10 percent opacity
or greater in the case of gases discharged from a pot furnace
larger than 550-lb charging capacity (EPA, 1977).
3.3 Performance Test
A performance test of a secondary lead smelter must be conducted
within 60 days after the facility has achieved its maximum production
rate and not later than 180 days after its initial startup, and at
such other times specified by the Administrator. Such a test consists
of three separate runs of which the arithmetic mean is the result for
determining compliance with NSPS.
No continuous monitoring requirement is set for secondary lead
smelters (40 CFR 60).
3.4 Definitions Applicable to Secondary Lead Smelters
Terms applicable to secondary lead smelters as defined in 40 CFR
60 include:
• Affected facility - with reference to a stationary
source, any apparatus to which a standard is applicable.
• Lead - elemental lead or alloys in which the predominant
component is lead.
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• Modification - any physical change in, or change in the
method of operation of, an existing facility which increases
the amount of any air pollutant (to which a standard applies)
emitted into the atmosphere by that facility or which results
in the emission of any air pollutant (to which a standard
applies) into the atmosphere not previously emitted.
• Opacity - the degree to which emissions reduce the
transmission of light and obscure the view of an object in the
background.
• Particulate matter - any finely divided solid or liquid
material, other than combined water, as measured by Method 5
of Appendix A to this part [Subpart A] or an equivalent or
alternative method.
• Reconstruction - the replacement of components in an
existing facility to such an extent that: (1) the fixed
capital cost of the new components exceeds 50 percent of the
fixed capital cost that would be required to construct a
comparable entirely new facility, and (2) it is
technologically and economically feasible to meet the
applicable standards set forth in this part.
• Reverberatory furnace - includes the following types:
stationary, rotating, rocking, and tilting.
• Run - the net period of time during which an emission
sample is collected. Unless otherwise specified, a run may be
either intermittent or continuous within the limits of good
engineering practices.
• Sampling time [for Method 5] - for each run shall be at least
60 minutes and the sampling rate shall be at least 0.7
dscm/hr (0.53 dscf/min) except that shorter sampling times,
may when necessitated by process variables or other factors,
be approved by the Administrator.
• Secondary lead smelter - any facility producing lead
from a lead bearing scrap material by smelting to the metallic
form.
• Shutdown - the cessation of operation of an affected
facility for any purpose.
• Startup - the setting in operation of an affected facility for
any purpose.
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• Test methods (explained in Appendix A of 40 CFR 60) -
- Method 1 to determine sample and velocity transversea
- Method 2 to determine velocity and volumetric flow rate
- Method 3 for gas analysis
- Method 5 to determine the concentration of particulate
matter and the associated moisture content
Sampling shall be conducted during representative period* of
furnace operation, including charging and tapping*
3.5 Regulatory Basis for Any Waivers, Exemptions, or Other
Tolerances
Occasionally, opacity standards do not apply, such as during
periods of startup, shutdown, and malfunction, or during periods of
excess emissions caused by post-blowing, unstable process condition!,
or emissions of uncombined water vapor (EPA, 1977). In addition, when
acceptable systems of emission reduction cannot meet the opacity
limits, a means is provided for exempting the source from the standard
at that time (39 PR 9309, March 8, 1974).
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4.0 STATUS OF CONTROL TECHNOLOGY
4.1 Scope of Industrial Operations
4.1.1 Production of Secondary Lead
Lead occupies a unique position among nonferrous metals in that
secondary lead production relies heavily on one source of scrap—used
batteries. More than 60 percent of all secondary lead is derived from
resmelting battery-lead plates. Other sources include pipe, cable
covering, type metal, solder, drosses and other by-products. Return
slag from smelting is also reused (Bureau of Mines, 1973, 1976;
Engineering-Science, Inc., 1977).
Secondary lead is smelted down from so-called old and new scrap
leads. Old scrap lead consists of discarded, dismantled, or worn-out
metallic items. New scrap or "prompt industrial scrap" is lead
generated at various points of the production process. It has never
been made into or used as an end product and is supplied directly to
•
smelters in larger, more uniform lots than old scrap (Fine et al.,
1973). Consumption of these various kinds of scrap lead is shown in
Table 4-1.
Secondary lead competes widely with primary lead, since most of
the same product needs can be met from both sources. In 1975, the
output of secondary lead (658,500 tons) represented approximately 51
percent of the total U.S. lead consumption. The 1975 production of
secondary lead was about 6 percent below the output of approximately
700,530 tons in 1974. Although the decrease in recycled lead from
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1974 is not fully explained, it was part of an overall drop in total
production and consumption of lead both in the U.S. and inter-
nationally. The Bureau of Mines (1975) noted a worldwide recession
and a decrease in demand for lead in automobile batteries. Secondary
lead production rose to a record 726,569 tons in 1976, then dropped
again in 1977 to a total estimated amount of 588,000 to 600,000 tons.
Overall, the increase in production of secondary lead by smelting of
TABLE 4-1
CONSUMPTION OF SCRAP LEAD IN THE U.S.
Amount Used By Remelters.
Smelters, Refiners (tons)
New3
Scrap Lead Type 1972C 1975d
Soft Lead
Hard Lead - -
Cable Lead - -
Battery Plates
Mixed Babbitt
Solder and Tinny Lead
Type Metals
Dross and Residues 114,988 136,066
Total 114,988 136,066
Old0
1972°
57,674
15,402
31,909
520,913
4,270
11,853
32,462
-
674,483
1975a
32,642
26,912
50,569
623,448
3,515
11,250
19,820
-
768,156
3Scrap lead never made into or used as an end product. It is
available in larger, more uniform lots than old scrap.
"Scrap lead that is a discarded, dismantled, or worn-out metallic
element.
cAmerican Metal Market, 1972.
dBureau of Mines, 1975.
4-2
-------
discarded melal from about 500,000 tons in 1955 to over 658,500 tons
in 1975 (Figure 4-1) represents an average annual growth rate of about
1.4 percent. However, decreases in the annual production of secondary
lead have also occurred in recent years. Early in the 1970s the Lead
Industry Association (1972) predicted a possible excess of lead supply
over demand before 1980. The Bureau of Mines (1973) predicted that
secondary lead production would increase at a faster rate than primary
production. This projection is supported by the fact that primary
production from domestic ores actually declined from about 573,000
tons in 1971 to slightly over 530,000 in 1975, while the output of
secondary lead increased by over 50,000 tons over that period (Bureau
of Mines, 1975).
In 1975, the secondary lead industry comprised about 85 predomi-
nantly small companies. Bureau of Mines figures showed 160 plants in
1967, 140 in 1973, and in 1975, "approximately 115 secondary plants
engaged in recovering lead and lead alloys from recycled scrap materi-
als." By 1977, the total number of such secondary smelters had
decreased further to 104. The Bureau of Mines figures apply to plants
which conduct smelting and auxiliary operations that change the nature
of the product metal from the state in which it is charged to the
furnace (Bureau of Mines, 1973, 1978). The average output per plant
in any given year is in the range of 5700 to 6000 tons. However, a
very wide variation occurs in annual production for individual
smelters. Viewed over a period of months, production of secondary
4-3
-------
1,600
1,400
1,200
o
4-1
t! 1,000
o
CO
CO
=}
o
CO
(U
800
600
400
200
0
Secondary production
1950
1955
1960
1965
1970
1975
Source: Bureau of Mines, 1975.
FIGURE 4-1
U.S. SECONDARY LEAD PRODUCTION
4-4
-------
lead is an intermittent operation. It is unusual for a smelter to
operate continuously up to capacity. Plants may be shut down for a
period of time and started up again when market conditions are more
favorable (Bureau of Mines, 1978). Therefore, annual production of a
plant is not be directly determined by daily capacity or vice versa.
The high degree of domination by a few companies in the secondary
lead industry is shown by the fact that the two largest producers,
operating 18 smelters, provided over half the total U.S. output in
1975. Informal estimates are that by 1977, their share of the market
may have been nearly 60 percent. More than 50 percent of the
remaining output (or some 20 percent of the total) is produced in 24
smelters operated by 13 other companies (Bureau of Mines, 1977; 1978).
Since more than 3/4 of the output comes from these 42 plants, the
total production of the remaining 70 small firms cannot exceed 24
percent of total output and may be nearer 12 percent. Earlier
estimates ascribed about 75 percent of production to four firms (EPA,
1973). Production data are regarded as proprietary, particularly
among the smaller firms and further details on distribution of output
are not available. However, a range of estimates can be made (Table
4-2). Estimates of production among the three categories of secondary
lead firms, annual averages per smelter, and average number of
operating days per year based on assumed plant capacity. Estimates in
this table as to share of production captured by the largest producers
are conservative.
4-5
-------
TABLE 4-2
ESTIMATED PRODUCTION OF SECONDARY LEAD
t
Total Annual
Number of Production, Production^
Category
Large Producers
Other Major
Producers
Small Producers
Total
Companies %
2 51
13 25
70a 24
85 100
Category
336,000
165,000
158,000
659,000
Per Co.
118,000
12,690
2,260
7,750
Number of
Smelters
18
24
73
115
Annual
Production
Per Smelter
18,660b
6,875
2,164
5,730
Operating Days/Year
Based on Selected Averages
for Smelter Capacity (TPD)
20 35 50 60
N/A N/A N/A 311
N/A 196 138 115
108 62 43 N/A
_ _ _ -
80
233
N/A
N/A
-
fEstimated from available approximations (1976)
Rounded-off.
Source: Bureau of Mines, 1975; 1977.
-------
Use of lead is expected to increase during the rest of the cen-
tury marked by changing patterns in consumption. Demand for secondary
lead from the printing industry and from manufacturers of paint
pigment is expected to decrease by the year 2000 (Brobst and Pratt,
1973). There will also be decreased usage of secondary lead in
gasoline, lead covered cable, plumbers' (caulking) lead foil, and
collapsible tubes (Fine et al., 1973). However, the demand for
secondary lead in storage batteries is expected to increase greatly
and, according to an extreme estimate, could triple or quadruple by
the year 2000 (Brobst and Pratt, 1973).
4.1.2 Geographic Distribution
Despite its concentration in the hands of a few predominant
companies which produce most of the total output, the secondary lead
industry is fairly well dispersed geographically. Secondary lead
smelters are present in all 10 EPA regions. Figure 4-2 shows the
general distribution of secondary lead smelters in operation. The
areas of highest concentration of secondary lead smelters are Chicago,
the Baltimore-Washington industrial corridor, and Perth Amboy, New
Jersey. These areas provide most of the old and new scrap utilized by
secondary lead smelters in the form of discarded batteries and zinc
and copper alloys.
4.1.3 Plants Subject to NSPS .
EPA (1973) originally estimated that an average of two new plants
would come on line each year and that one or two would be modified or
reconstructed. This estimate correlates reasonably well with
4-7
-------
I
CO
LEGEND:
• Secondary lead smelter as of 1973
(Chapman, 1973; Bureau of Mines, 1976)!
O Secondary lead smelter under construction
in 1978 (MITRE Corporation, 1978).
-------
projections based on the average annual growth rate of the secondary
lead industry (1.4 percent). The estimate of about three new plants
every 2 years does not take into account new plants added to replace
old ones. Of course, no estimate of reconstructed or modified plants
is provided by projections based on the industry growth rate.
The estimates of two new plants per year agrees with latest
figures of the Bureau of Mines (1978) which show six plants completed
or scheduled for completion in the 1977-1979 period (including major
expansions of existing plants).
At least six plants were tested after the promulgation of NSPS
for secondary lead smelters. Evidence of six tests was obtained
chiefly through the Compliance Data System, a computerized means of
recording information necessary for the enforcement of NSPS, during a
recent survey of the 10 EPA regions (MITRE Corporation, 1978).
However - results of only four tests were available.
4.2 Production of Secondary Lead
4.2.1 Reverberatory Furnace Operation
Reverberatory furnaces produce what is termed semisoft lead,
containing typically from 3 to 4 percent antimony and less than 0.05
percent copper (Danielson, 1973; Engineering-Science, Inc., 1977).
The process flow in a reverberatory furnace is shown in Figure 4-3.
The details of the cooling and collecting system may differ greatly,
depending upon the type of controls installed, as discussed in Section
4.3.
4-9
-------
Emissions
Fuel (Oas or Oil)
Conbustlon Air
Lead Scrap
Charge—
r
s
Ventilation Gas
mJ
_t
V
IT
Process Gas
->
1
Cooling
1
System
T
Lead
Product
Reverberatory
Furnace
Dross
Fan
Dust Recycle
Sources: Danlelson, 1973.
EPA, 1973
Mantell, 1975.
Engineering-Science, Inc., 1977.
-------
When a smelter is operating, reverberatory furnaces may operate
on a continuous basis, and are used in sweating operations and in
reclaiming lead from oxides and drosses. Sweating utilizes differ-
ences in melting point temperatures to separate lead from other
metals. Material for sweating and for reclamation from lead oxides
and drosses may be charged in the reverberatory furnace at one time.
Such a furnace radiates heat from burners and the refractory lining
into the metal charge within it. The furnace operates at a tempera-
ture of about 2300°F and at near atmospheric pressure so that air will
not leak in. Air blown through the molten metal eliminates impuri-
ties. Attempts are made to keep as much heat as possible in the
furnace. Only enough draft is provided to remove smoke and fumes.
Dross formed in the furnace floats on top of the molten metal and is
removed periodically in an operation known as slagging. The slag may
be later rerun in a blast furnace. The lead product is periodically
tapped into molds.
External hoods are used with the objective of passing all smoke
and fumes to a collector. To keep cool air out of the furnace,
ventilating air for all the hoods is similarly vented. The spout
through which the molten lead product pours is the only exception to
the hooding. The collected dust is valuable for recycling as fines,
either in a reverberatory or a blast furnace. In a continuous
operation, a typical weight balance of material shows:
• 47 percent metal recovery as lead product
4-11
-------
• 46 percent recovery of slag, which may be at least partially
recharged
• 7 percent loss as smoke and fumes (Danielson, 1973;
Engineering-Science, Inc., 1977).
4.2.2 Blast Furnace Operation
A blast (cupola) furnace is cylindrical and vertically oriented
and is batch-fed from a car or hopper near the top at a fairly con-
stant rate (Figure 4-4). Although material content varies somewhat, a
typical charge may consist of:
• 82.5 percent drosses, oxides and slags, including material
rerun from reverberatory furnaces and pot-furnace refining
• 4.5 percent highly silicated slag rerun from previous blast
furnace operation
• 4.5 percent cast-iron scrap
• 3 percent limestone
• 5.5 percent coke.
Smaller percentages of iron may be used, while the percentages of
rerun slags, limestone and coke may run as high as 8, 10 and 8,
respectively. The combustion of coke furnishes heat for the process
and also facilitates chemical reduction of lead oxide in the feed.
Forced air, which may be oxygen enriched, is introduced near the
bottom through openings known as tuyeres at a gage prespure of about 8
to 12 oz/in2. Slag floating on top retards oxidation and is tapped
periodically. About 5 percent of the recovered slag may be rerun
later. The lead product is drawn off more or less continuously from
the bottom and may be retained in lead holding pots for further
melting and refining. Blast furnaces produce what is termed hard or
4-12
-------
I
I-*
U>
NATURAL GAS
AFTERBURNER
TORCH
COOLING «
WATER ~*-
OUT
BLAST
COOLING .
WATER IN
COOLING
WATER
SPRAY
• '
• * •
Source: EPA, 1973.
CHARGE
MATERIALS
LEAD
PRODUCT
I
\n n n/
FIGURE 4-4
PROCESS FLOW SKETCH OF LEAD BLAST FURNACE
OF CUPOLA WITH COOLING SYSTEM
FLUE GAS
-------
antimonial lead containing 'as much as 10 percent antimony as well as
small amounts of arsenic, copper, nickel and tin (EPA, 1973;
Danielson, 1967; Engineering-Science, Inc., 1977; Mantell, 1975).
A typical blast furnace may be rated at 50 tons per day of prod-
uct (over 2 tons/hr process weight) with a flow rate of about 15,000
dry standard cubic feet (dscf)/min. EPA (1973) projected the new fur-
naces to range in size from 20 to 80 tons/day ingot production with a
gas flow rate of 10,000 to 40,000 dscf. Often blast and reverbera-
tory furnaces in a single installation combine the effluents that are
run into a brick-lined chamber with an afterburner. The afterburner
is necessary to incinerate oily and sticky material and to convert CO
to C0o» No afterburner is required with the reverberatory furnace,
previously mentioned, since the excess air necessary for combustion
and the operating temperature used ensure that CO and hydrocarbon
materials are fully incinerated. In one Pennsylvania plant consisting
of two blast furnaces and one reverberatory furnace at a combined
production capacity of 100 tons/day of alloyed lead, the process gas
flows into the control system at a rate of 65,000 ft^/min from the
three furnaces and from a set of lead holding pots; the ventilation
Q
gas flow rate is 60,000 ftj/min. To contain emissions a furnace
must be sealed and all gases vented to a control system (Danielson,
1967; EPA, 1973; Mantell, 1975).
4.2.3 Pot Furnace Operation
Pot furnaces use a batch process to remelt lead for alloying or
refining. At a temperature range of 600° and 900°F, the process may
4-14
-------
require from a few hours to more than 2 days. The metal is fed into
open top kettles that are ceramic lined and usually fired by natural
gas burners placed underneath. The open top of the pot is hooded so
that lead oxide fumes will not escape into the working area. A soft
lead of high purity (which may exceed 99.9 percent lead) can be
produced by the removal of copper and antimony. A hard lead product
results from removing arsenic, copper and nickel. For alloying,
ingots of a specified metal are added in the desired percentages.
Copper, tin, arsenic, antimony, and nickel are commonly employed in
alloys. Emissions from the furnace and from the holding, melting and
refining pots are vented to a control system. The lead-containing
dust is recycled to a reverberatory furnace. Figure 4-5 shows the gas
flow for a pot furnace controlled by a baghouse (Danielson, 1967; EPA,
1973; Engineering-Science, Inc., 1977).
4.3 Pollutant Emissions
Emissions may occur from a blast furnace via the charging doors
and metal tapping spout, as well as from the furnace stack. These
outlets are hooded to provide for venting dust and fumes through the
control system. In the reverberatory furnace the charging point, the
furnace itself, and the repositories of recovered slag and metallic
lead are hooded. Hooding is also provided for emissions from holding,
melting and refining pots. Depending on the efficiency of the hoods
in trapping dust and smoke, some may escape as fugitive emissions. In
a pot furnace only the open top of the pot provides a source of
emissions (Engineering-Science, Inc., 1977; EPA, 1973).
4-15
-------
EMISSIONS
FROM FURNACES
-4FT3 ET^3FrpCT73C!
\J\J\J\J\J
HOLDING, LEAD MELTING,
AND REFINING POTS
DUST RECYCLED TO REVERBERATORY FURNACE
«
Source: EPA, 1973.
FIGURE 4-5
CONTROLLED LEAD POT AND VENTILATION SYSTEM
WITH BAGHOUSE
-------
Particulate emissions from blast and reverberatory furnaces
contain oxides and sulfides of lead, small amounts of other elements,
coke fuel, and oil vapor. The high temperature used in a reverber-
atory furnace (approximately 2300°F) accounts for a relatively high
mean loading (in pounds per ton of charge) of oxides of sulfur,
chiefly 802* The sulfuric acid in lead batteries smelted accounts
for much of the sulfur emissions from a typical furnace, along with
casings and other impurities charged. On the basis of 7 percent loss
of charge, uncontrolled particulate emissions would be on the order of
140 Ib/ton of material charged to the furnace. Tests have shown that
the actual particulate emission rate varies widely. Estimates by EPA
are shown in Table 4-3. Particulate emissions from pot furnaces are
more than two orders of magnitude lower than from blast or reverbera-
tory furnaces, less than 1 Ib/ton charged to the furnace. A rela-
tively low temperature is used with pot furnaces, and there is less
turbulence than with the other types.
The particulates emitted by secondary lead smelters are high in
lead content, chiefly in the form of lead oxide. It has been esti-
mated that on an uncontrolled basis lead emissions from blast and
reverberatory furnaces amount to about 56 and 53 Ib/ton of product,
respectively, which is approximately 23 percent of the total particu-
late emission rate (EPA, 1977).
The concentration of particulate matter in emissions from blast
furnaces (prior to application of control) may be high, as much as
12.3 gr/dscf in one test reported. Typical ranges for concentration
4-17
-------
TABLE 4-3
SECONDARY LEAD SMELTERS
ESTIMATED UNCONTROLLED EMISSION RATES
(Ib/ton charge)
JS
h-«
oo
Test Data
• RANGE
AP-42
Tests Reported by EPAa
• MEAN OR SINGLE VALUE
Danielson (1 Test)b
Tests Reported by EPA (Average)3
AP-42
Danielson (Weight Balance)b>c
Reverberatory
Particulates
56-313
N/A
104
N/A
147
140
Furnace
S02
71-88
109-185
N/A
146
80
N/A
Blast Furnace
Particulates
21-381
N/A
172
N/A
193
140
S02
18-110
0.1-64
N/A
41
53
N/A
Pot Furnace
Particulates
N/A
N/A
N/A
N/A
0.8
N/A
S02
Negligible
N/A
N/A
N/A
Negligible
N/A
Background Information, Vol. I, June, 1973.
bAir Pollution Engineering Manual, 2d Ed. (EPA, 1973).
Q
7% of charge estimated carried out as dust in smoke and fumes.
-------
of particulates in stack gases from reverberatory furnaces are
reported to be from 1.4 to 4.5 gr/dscf, but higher values occur, such
as 4.98 gr/dscf (Danielson, 1973; Engineering-Science, Inc., 1977;
EPA, 1975).
Particles emitted from blast furnaces are much larger than those
from reverberatory furnaces and range in size from 1 to 100 microns.
By contrast, particulate sizes from reverberatory furnaces range
between 0*07 and 0.4 microns (as determined from analysis of baghouse
content) with a reported mean size of 0*3 microns. These particles
are nearly spherical and have a tendency to agglomerate (Danielson,
1973; Engineering-Science, 1977).
On the average, S02 emissions from reverberatory furnaces are
higher (Table 4-3) than those from blast furnaces 80 and 53 Ib/ton of
charge, respectively. However, the upper limit of the range of
emissions from blast furnaces exceeds that for furnaces of the
reverberatory type. Pot furnaces emit only negligible amounts of
S02.
Emission factors from furnaces used in secondary lead smelters
have not been determined as explicit functions of the variables that
affect them. However, a number of factors that influence the emission
rate have been briefly presented in the Inspection Manual for
Enforcement of New Source Performance Standards, Secondary Lead
Smelters (Engineering-Science, Inc., 1977). These include:
• production rate
4-19
-------
• quality of charge (i.e., increase in dirt or oil on the scrap
increases emissions)
• method of charge (i.e., adding essentially all of the charge
at the beginning of the heating process results in lower
emissions than by intermittently charging a hot operating
furnace)
• fuel rate
• oxygen rate
• slag cover (i.e., a thick layer tends to harden, increasing
lead oxide emissions; prior to the time of hardening mass
emissions are decreased by a thick layer)
• length of time over which a charge is smelted
• slag fines charged to the furnace (i.e., an increase in
these results in a higher rate of particulate emissions)
• for blast furnace, rate of air blowing through the tuyeres.
4.4 Applicable Controls
4.4.1 Methods and Effectiveness
In the past, various control methods have been used in secondary
lead smelters to meet state and local requirements for particulate
removal and to recover the lead dust valuable for recycling. These
have included centrifugal dust collectors, settling chambers and
low-energy scrubbers. In the Background Information Document for the
proposed NSPS, EPA noted that "At well controlled secondary lead
smelters, either baghouses or high-energy scrubbers are used to
collect dust and fumes from the furnace." The Agency predicted
further "The predominant control devices for the secondary lead
industry are expected to be fabric filters, along with a small number
of high-energy scrubbers." (EPA, 1973). Some authorities consider
4-20
-------
the baghouse to be the most effective control system (Danielson, 1975;
EPA, 1977), and the use of fabric filters predominates over use of
venturi scrubbers in the secondary lead industry (Engineering-Science,
1977).
Baghouses used to control emissions from secondary lead smelters
commonly employ a pull-through, tubular bag made of either dacron or
fiberglass. To facilitate maintenance, the baghouses are usually
compartmentalized. Because the temperature of the gas is very high
when it leaves the furnace stack (up to 1350°F), it is necessary to
employ cooling measures that reduce the temperature to about 500°F for
fiberglass fabric filters and about 300°F for dacron filters. Tempera-
ture is reduced by passing the gas through radiant or water-jacketed
cooling ducts. The cooling duct system may use a water spray and/or
U-tube coolers. Although dilution air may also be introduced to
effect cooling, the volume of gas that may be pulled is limited by the
capacity of the system fan, so that the success of the system depends
on radiation and/or water-cooling. It is also necessary to ensure
that sparks and other burning material do not come in contact with the
fabric" of the filter bag. As previously noted, with blast furnaces an
afterburner is employed to ensure complete combustion of such material
before it enters the baghouse. To prevent condensation within the
baghouse, the entering gas temperature must be maintained at 50°F
above the dewpoint; otherwise condensation results in caking on the
bags and a pressure buildup that will ultimately rupture the fabric.
Also, sulfur in the cake forms damaging acids. A ratio of air to
4-21
-------
cloth of about 2:1 is commonly employed. The pressure drop is usually
up to 4 inches water gauge (WG) (Danielson, 1973; Engineering-Science,
Inc., 1977).
Venturi scrubbers are also used for emission control, although
less widely than baghouses. These scrubbers commonly employ a pres-
sure drop between 30 and 100 inches WG. Efficiency of the scrubber is
affected principally by the pressure drop and secondarily by the rate
of water flow. A water quench is typically used which lowers gas
temperature. With a pressure drop of 60 inches, a throat velocity of
about 200 ft/s and a water flow of 3 gal/min is typically used.
Figure 4-6 compares the more rigorous requirements of the current
NSPS for particulate emissions from secondary lead smelters with those
provided by earlier EPA guidelines for State Implementation Plans
(SIP). The SIP formula specified maximum allowable emission rates in
pounds per hour as a function of hourly processing weight. To facili-
tate comparison, the graph of the permissible level under NSPS has
been converted to the same units of measure as SIPs, on the basis of a
representative furnace with a daily capacity of 50 tons of product
(EPA, 1973) and a flow rate of 15,000 scf/min. Such a plant producing
4160 Ib/hr (2.08 tons/hr) would be allowed to emit up to 2.72 Ib of
particulates per hour. An uncontrolled emission rate from such a
plant of 150 Ib/ton of product (Table 4-3) would produce an hourly
inlet loading to the control system of 312 Ib, requiring an efficiency
4-22
-------
to
U)
£
•H
00 x-s
•H £
W Io
0) ^>
F"H
*
ft
60
40
20
10
4
2
-6
.4
.2 -
0
m
o
o
o o
0
in
O
en
o
o
o
O O O
O O O
o »n o
CM ro in
o
o
o
o
o
o
n
o
CM
o
o
o
Process Weight Rate
(Ib/hr)
Source: U.S. Environmental Protection Agency, 1973
FIGURE 4-6
COMPARISON OF ALLOWABLE EMISSIONS FOR PARTICULATES
(50 TO 50,000 LB/HR) VS. PROCESS WEIGHT FOR
NSPS AND STATE IMPLEMENTATION PLANS
-------
of 99.1 percent; whereas an uncontrolled rate of 193 Ib/ton (average
for blast furnaces as listed in Table 4-3) would require an efficiency
of over 99.3 percent (Danielson, 1973; EPA, 1973; 1975).
However, even higher loadings may be encountered. The achieve-
ment of 12.3 gr/dscf reported in one test (Danielson, 1973) would
require an efficiency of over 99.8 percent in order to meet the NSPS
level of 0.022 gr/dscf or less. Figure 4-7 shows efficiencies
required of control systems as a function of inlet loading, again
using the basis of the representative furnace with a ratio of exit
flow-rate (in dry standard cubic feet per minute) to pounds of lead
produced of 220.
To achieve the control efficiencies required, more than one
control system may be combined in a secondary lead smelter. Table 4-4
shows systems associated with secondary lead furnaces together with
estimated efficiencies. These efficiencies do not necessarily reflect
BTS. A baghouse may be combined with a wet or dry cyclone. Some
plants with heavy use of lead batteries as a source of scrap
reportedly combine the baghouse with a venturi scrubber. After the
exhaust gas has passed through a fabric filter, the scrubber is used
to remove SC^ that may be present from sulfuric acid in the
batteries. (EPA, 1975; Engineering-Science, Inc., 1977). Control of
S02 is discussed in Section 6.
Current control technology provides for the high collection effi-
ciencies demanded to meet particulate standards, as shown in the test
4-24
-------
1.0
N>
U1
X
•O
&
« 0.07
0.3 0.4 0.50.6 0.8 1.0
2.0 3.0 4.05.06.0 8.0 10
Inlet Loading (gr/dscf)
20
30 40 50 60 708090100
Sources: EPA, 1973; 1975.'
60 80 100 150 200 300 400
Uncontrolled Emission Rate in Pounds/Ton Charged
(Based on 50 Tons/Day, 15,000 dscf/Minute)
FIGURE 4-7
EFFICIENCIES REQUIRED TO MEET NSPS FOR
PARTICULATES AS FUNCTION OF
UNCONTROLLED EMISSION RATES
-------
TABLE 4-4
ESTIMATED PARTICULATE CONTROL EFFICIENCY FOR
EQUIPMENT USED WITH SECONDARY LEAD FURNACES
Furnace Type Particulate Control
Control Device Applicable Efficiency, %a
Fabric Filter (Baghouse) Blast 98.4
Reverberatory 99.2
Dry Cyclone Plus Fabric Filter Blast 99.0
Wet Cyclone Plus Fabric Filter Reverberatory 99.7
Settling Chamber Plus Dry
Cyclone Plus Fabric Filter Reverberatory 99.8
Venturi Scrubber Plus Demister Blast 99.3
aNot necessarily efficiencies achieved by BTS.
Source: EPA, 1975.
results and in analysis of rated capabilities of control equipment.
However, very high pressure drops are demanded of a venturi scrubber
for high efficiencies in removing small particles. For example, a
pressure drop of greater than 40 inches WG would be required to
achieve 99 percent efficiency with particles less than 0.4 microns
such as those emitted by reverberatory furnaces (Soderberg, 1974).
Therefore, a pressure drop of up to 100 inches WG should not be sur-
prising (Engineering-Science, 1977).
Studies of the air around secondary lead smelters in Canada
showed the suspended lead particles to be relatively large and
nonrespirable. The influence of fugitive emissions was suspected.
However, comprehensive data are lacking, and it would be unwise to
4-26
-------
draw general conclusions from these limited observations (Roberts et
al., 1974). Based on physical considerations, it might therefore be
expected that the lead content of participates emitted from a control
system would be lower than that on an uncontrolled basis. Generally,
the larger particles are easier to trap both in a fabric filter and in
a scrubber control device, whereas efficiency of the collector systems
tends to decrease with particle size.
Test results on secondary lead furnaces equipped with scrubbers
and/or baghouses may support this conjecture (EPA, 1973; Davis, 1973).
In six tests conducted on emissions from seven furnaces, the lead
emissions represented about 19 percent of the particulate emission
rate. This compares with EPA estimates (1977) of 23 percent lead
content of uncontrolled emissions. Lead emissions under controlled
conditions are discussed further in Section 6.3.
4.4.2 Cost to Industry
The cost of controls for particulate emissions depends not only
on the type of system selected but also on operating variables at a
given secondary lead smelter.
4.4.2.1 Baghouses. Capital and annual costs for a fabric-
filter control system fitted to blast and reverberatory furnaces have
been calculated by EPA (1977) on the basis of typical or model fur-
naces, with some operating parameters specified and others implicitly
averaged out. It was found in the analysis forming the basis of these
calculations that capital costs for both furnace types were primarily
a function of flow rate in actual cubic feet per minute (ACFM) of gas
4-27
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exiting the furnace. For furnaces with flow rates of between 10,000
and 100,000 ACFM, the capitalization costs were expressed as:
C = 906 Q°*6 (reverberatory furnaces)
C = 2460 Q0'6 (blast furnaces)
where C is expressed in dollars and Q represents flow rate in actual
cubic feet per minute. These results are plotted in Figure 4-8.
Capitalization costs comprised equipment, installation, interest
during construction, taxes, engineering, and other miscellaneous items
including a 20 percent allowance for contingencies (EPA, 1977).
Annualized costs included capital recovery, utilities, operating
labor, maintenance, and overhead. These costs were expressed as a
function of flow rate and of annual hours of labor. Specifically,
annualized costs in dollars were expressed as:
A = 0.364Q + 19.6H + 236Q0'6 for reverberatory furnaces
A = 7.25Q + 642Q0-6 + 19.6H for blast furnaces
where Q represents flow rate as before and H denotes annual labor
hours.
Costs were calculated for reverberatory and blast furnaces with
a capacity of 50 tons/day. For the reverberatory furnace an exhaust
rate of 33,500 ACFM at 1350°F was assumed and for the blast furnace a
rate of 32,000 ACFM at 500°F. These flow rates correspond approxi-
mately to about 17,000 and 10,000 dry standard cubic feet per minute
(dscfm) depending on the percent of moisture in the gas. For annual-
ized cost it was assumed that 3000 hours of labor were required per
year.
4-28
-------
10,000
9,000
8,000
7,000
6,000
5,000
4,000
3,000
2,500
2,000
1,500
CO
!H 1,000
£ 900
M-. 800
I 70°
? 600
9
O
•s
4J
CO
O
o
cfl
4-1
CO
O
500
400
300
250
200
150
BLAST FURNACE
REVERBERATORY FURNACE
10 15 20 25 30 40 50 60708090100
Flow Ratze of Exit Gas
(thousands of actual cubic feet/minute)
Source: EPA, 1977.
FIGURE 4-8
CAPITAL COSTS OF A FABRIC FILTER CONTROL SYSTEM FOR
BLAST AND REVERBERATORY FURNACES AS FUNCTIONS OF
FLOW RATES
4-29
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For the 50 ton/day reverberatory furnace, capital costs were
calculated by EPA to be $470,000 and annualized costs were $194,000
(mid-1976 dollar values). For the corresponding blast furnace, the
capital and annualized costs were much higher—$1.24 million and
$615,000, respectively. Credit for recycling the dust estimated to be
collected at a value of 5 cents/lb would result in decreasing annual-
ized costs by $141,000 for a reverberatory furnace and $150,000 for a
blast furnace (EPA, 1977).
Earlier analyses indicated that the equipment and installation
cost of baghouse systems used to control reverberatory furnaces would
be higher than that for a blast furnace of the same capacity. A study
by the Industrial Gas Cleaning Institute (Hardison et al., 1970) was
based on a survey of companies supplying control systems to secondary
lead smelters. The figures of this study agree with those of EPA
(1973) that rate the reverberatory furnace the more expensive of the
two. The Industrial Gas Cleaning Institute (IGCI) study derived costs
as a logarithmic function of flow rate in actual cubic feet per
minute, which was then equated to a furnace of specified capacity.
The relation of flow rate to furnace capacity does not agree with that
used in the model plant figures cited earlier from EPA (1977); thus
two cost figures, one based on flow rate and the other on furnace
capacity, give a range of values for comparison. The IGCI figures are
much lower than the 1973 EPA estimates for furnaces of equivalent
size. The various estimates are summarized in Table 4-5.
4-30
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TABLE 4-5
COMPARISON OF COST ESTIMATES FOR CONTROL OF
SECONDARY LEAD SMELTERS - FABRIC FILTER SYSTEM
(dollars)
Cost
EPA (1977)
IGCI (1970)
EPA (1973)
Reverberatory Furnace
Capitalization Cost 474,000
Annual Operating
& Maintenance Costs3
Annualized Costsb 53,000
Blast Furnace
Capitalization Costs 1,240,000
Annual Operating
& Maintenance Costs
Total Annualized Costs 465,000
168,000-260,000
9,100-14,250
61,000-82,000
3,800-6,000
188,000
51,000
157,000
21,000
aEPA operating and maintenance costs are included in total annual-
ized costs.
Includes credit from recycled dust (deducted from total annual-
ized costs).
4.4.2.2 Venturi Scrubbers. The most precise recent cost esti-
mates of venturi scrubber control systems were developed by EPA
(1978). Computer modeling techniques were used to calculate costs for
both blast and reverberatory furnaces as functions of flow rates and
efficiency in particulate removal. Parametric input was obtained for
cost factors for the various system components (including installa-
tion) developed in a study under contract to EPA (Kinkley and Neveril,
4-31
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1976). On the basis of 99.5 percent efficiency in particulate
removal, capitalization costs for blast and reverberatory furnaces of
50-ton/day capacity can be estimated at about $775,000 and $580,000,
respectively (in 1976 dollars). These costs are based on exit rates
of furnace gas of about 32,000 and 33,500 ACFM, respectively, so as to
derive estimates comparable to those of the model furnaces for which
baghouse costs were developed by EPA (1977).
These cost estimates for venturi scrubbers may be compared with
those from other sources, as shown in Table 4-6. This table expres-
ses costs for 50 ton/day furnaces in thousands of 1978 dollars. Flow
rates were used to scale costs not estimated for secondary lead smel-
ters. It can be seen that the above EPA estimates for blast and
reverberatory furnaces bracket the estimate of about $640,000 from a
control equipment manufacturer. Differentiation between furnace types
was not feasible for this estimate. Estimates developed earlier are
much lower, even after applying inflation factors for increases in
costs of machinery and equipment (U.S. Department of Commerce, Bureau
of the Census, 1976).
The IGCI estimated costs for a high-efficiency venturi scrubber
are about $137,000 for a 50 ton/day blast furnace, assuming only
14,700 ACFM. With an assumed flow of 32,000 ACFM, the corresponding
IGCI costs increase to about $175,000. For a reverberatory furnace,
the cost estimates on a 50 ton/day and 33,500 ACFM basis are, respec-
tively, about $103,000 and $115,000. These figures agree with EPA
(1978) estimates in being higher for a blast furnace and lower for a
4-32
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TABLE 4-6
COMPARISON OF COST ESTIMATES FOR CONTROL OF
SECONDARY LEAD SMELTERS WITH VENTURI SCRUBBERS
($ thousands)
Manufacturer's
Estimate(l978)a
Combustion
IGCI (1970) Equipment Associ-
EPA (1978) EPA (1973) Hardison et al. (1970) ates (1978)
Source Reverberatory Blast Reverberatory Blast Reverbatory Blast (Not distinguished)
Capitalization
Costb 580 775 125 123 115 175 640
1978 dollars 669 895 202 199 184 280 640
Annual Operating
& Maintenance
Costs N/A N/A 1 1 N/A
1978 dollars N/A N/A 1.6 1.6 N/A
Total Annualized
Costs N/A 36 80 N/A N/A
1978 dollars 234 313 58 128 N/A N/A
Assuming Credit
for Recycled Fines
1978 dollars 152 226 N/A N/A N/A
aBased on conversion from estimate in dollars/megawatt, assuming a basis of flow rate
for smelters that corresponds to a 9-MW power plant; type of furnace not distinguished.
^As provided by source (i.e., before conversion to 1978 dollars).
-------
reverberatory furnace than the EPA (1973) estimates for venturi scrub-
ber capitalization costs. Direct comparison of estimates from various
sources is difficult because of different assumptions regarding costs.
It is not known what items were included or what efficiency in
particulate control was assumed.
In estimating fixed annual costs for control systems using
venturi scrubbers to control lead emissions from various sources, EPA
recently used as a general rate 20.28 percent (including taxes) of
total capital investment (EPA, 1977). Operating and maintenance costs
are estimated to range generally between 8 and 18 percent of total
capital investment, with 13 percent an average figure although very
high percentages of up to 40 percent are noted (Kinkley and Neveril,
1976). On this basis, a rate of 35 percent may be assumed for total
annualized costs. These would accordingly run about $234,000 each
year for a reverberatory furnace and about $313,000 for a blast
furnace. Total annualized costs for the earlier EPA estimates and
annual operating and maintenance costs as estimated by IGCI are also
shown in Table 4-6.
EPA (1975) originally estimated the value of recycled lead-bear-
ing dust from venturi scrubbers to be half that from fabric filters.
Applying this factor to the credit for recycled dust from baghouses of
$150,000 for blast and $141,000 for reverberatory furnaces (EPA, 1977)
and escalating the value to 1978 dollars, total annualized costs would
be reduced to about $226,000 for a blast furnace and $152,000 for a
reverberatory furnace as shown in Table 4-6.
4-34
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A significant feature that emerges from the range of cost esti-
mates is the effect of annualized costs of controls per ton of pro-
duct. Originally, EPA (1973) estimated the annual cost per ton of
lead produced to be $1.65 for reverberatory furnaces and $4.05 for
blast furnaces. Both figures were based on fabric filter control;
with venturi scrubbers, the cost per ton estimates increased to $2.86
and $6.40, respectively. A representative 50 ton/day furnace was
assumed for the estimates. These early estimates appear to have been
too optimistic. From the Bureau of Mines statistics previously
considered in Section 4.1.1, the average annual production of a
secondary lead plant of about 6000 tons is close to the average output
of 6875 tons/year of the 24 smelters of the second-largest set of
producers, which produce approximately 50 tons/day (Table 4-2). The
two largest producers operate smelters that are larger than 50
tons/day; whereas small plants operate smelters of much lower
capacity. The average output in any year varies, but taking the 1975
figure of 6875 tons as a basis for a representative 50 ton/day
smelter, annualized costs can be seen in Table 4-7. The costs as
percentage of the price per ton of lead product are based on
escalating the average 1976 price to 1978 dollars by an assumed
inflation rate of 7.5 percent per year, which is about the increase in
1976 price per ton of lead over that for 1975.
It may be reasonably assumed that new furnaces will be larger
than the previous average sizes. Information available to the Bureau
4-35
-------
TABLE 4-7
ESTIMATED COSTS OF CONTROL (ANNUALIZED BASIS)
(1978 dollars/ton of lead)
Reverberatory Furnace Blast Furnace
Venturi Venturi
Cost Baghouse Scrubber Baghouse Scrubber
Total Annualized
Costs ($000) 61 152 536 226
Average Cost
(Dollars/Ton) 9 22 78 33
Value of Lead
Product (%)
($534/ton) 2 4 14 6
of Mines (1978) indicates furnaces which have or will come on line in
the 1977-1979 period to range from 27,000 up to 70,000 ton/year
capacity and a daily capacity of more than 100 tons.
However, it is difficult to convert EPA estimates to larger
furnaces or to estimate the costs involved on a basis of dollars per
ton of product. On the one hand, estimates provided by IGCI (Hardison
et al., 1970) were based on flow rates as a linear function of size of
furnace. Therefore, no economy of scale is achieved and the cost of a
specific control system per ton of product for a given type of furnace
does not vary. On the other hand, flow rates as used in more recent
calculations by EPA (1978) represent a second degree function of
furnace capacity from which significant economies of scale result.
The annual production of these larger furnaces is unknown. It is
reasonable to relate control costs for a 50-ton day furnace to average
4-36
-------
production figures, because such a furnace can be taken as typical of
existing plants. However, estimates for new furnaces twice as large
or larger would have to be based on predictions as to future annual
production and the relative share of the market that these newer and
bigger plants will capture. The very limited data available will not
support precise calculations but approximations are possible; these
indicate the range of reduction in control costs per ton of product
that result from estimates based on much larger furnaces.
Calculations by EPA (1978) for reverberatory furnaces equipped
with venturi scrubbers reflect an increase of under 15 percent in flow
rate for a furnace twice the capacity of that previously taken to
represent a 50-ton day furnace. The increase in capitalization costs
is a relatively modest 7 percent. For blast furnaces, an increase in
flow rate of approximately 50 percent is postulated when the furnace
capacity is doubled. The increase in capitalization costs is about 32
percent.
These increases in assumed flow rate may also be applied to
furnaces equipped with fabric filters. The estimated flow rates can
then be used to derive new capitalization estimates from the formulas
used by EPA (1977) as previously cited. (These estimates may also be
read from the graphs in Figure 4-8.) On this basis, the blast furnace
with a capacity of 100 tons or more per day would use a flow rate of
about 50,000 ACFM, and the reverberatory furnace a rate of about
40,000. Applying these approximations to the cost functions
4-37
-------
previously cited results in estimates of about $1.62 million and
$520,000 for blast and reverbatory furnaces, respectively. These
represent relatively modest increases of about 31 and 11 percent,
respectively, in the cost of controls for furnaces of more than double
the original size.
When these percentages are applied to the estimated annualized
costs for furnaces of the respective types of furnaces and control
systems, the results are:
Annualized Costs (Thousands
Furnace of 1978 Dollars)
Reverberatory furnace, fabric filter 68
Reverberatory furnace, venturi scrubber 163
Blast furnace, fabric filter 702
Blast reverberatory furnace, venturi
scrubber 298
Relating these costs to furnace output requires similar assump-
tions to those already made. In the absence of more specific data, it
is not unreasonable to assume that the production of these furnaces
will be approximately twice the annual output of the smaller typical
furnaces half their size. On the basis of 13,000 tons of lead/year,
the cost of controls per ton would be about $54 and $23 for blast
furnaces with fabric filter and venturi scrubber, respectively.
Corresponding figures for reverberatory furnaces would be about $5 and
$13/ton.
4-38
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While these estimates necessarily remain conjectural, they
indicate the possibility that the increase in price of a ton of
secondary lead necessary to recover the increase cost of controls per
ton of lead product for the furnaces subject to NSPS may be on the
order of 60 to 70 percent of the estimates shown in Table 4-7.
Some of the cost increase due to controls might be absorbed in
lower prices paid for lead scrap, but a substantial part or all of the
cost will be passed to the consumer. Figures for the entire non-
ferrous metal industry showed the net income after taxes to be in the
range of 4 percent for 1976-77 (Levine, 1978). These averages include
large primary producers, as well as secondary smelters. Information
on the secondary lead industry alone is not available. It is certain
that many small smelters will earn a smaller net income and could face
severe difficulties in modifying or reconstructing a furnace.
4.5 Energy and Other Resource Requirements
Requirements for additional consumption of energy and other
resources are very small for fabric filter control systems that
operate at a nominal pressure drop of between 3 to 7 inches water
gauge, with an average of 4 inches (Engineering-Science, Inc., 1977;
Soderberg, 1974). Additional requirements imposed by the use of ven-
turi scrubbers may be calculated in terms of horsepower necessary to
provide high pressure drops and flow of water used in wetting and
separating the particles.
4-39
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Horsepower requirements as a function of pressure drop and fan
efficiency are shown in Figure 4-9. Results in terms of additional
energy and fuel consumption are shown in Figure 4-10, assuming that a
plant operates on the average for 2800 hr/yr. This figure is based on
the average annual plant output of 5725 tons and a typical capacity of
50 tons/day. Further assumptions have been made regarding the amount
of Btu as heat input required per kilowatt-hour (1 kW-hr represents
0.7457 hp-hr) as shown in the figure. The fuel requirements are pre-
sented in terms of barrels of oil equivalent to provide the necessary
heat input, on the assumption of 6 million Btu per barrel of oil. The
results represent a wide range because of variations possible in both
fan efficiencies and pressure drop. However, the fuel requirements
are on the order of 1000 barrels of oil equivalent per plant per year.
Water requirements may be estimated on the basis of a typical
plant with a gas flow rate of 15,000 cfm. Various ratios of water in
gallons per minute to flow rate in thousands of cubic feet per minute
may be employed in wet scrubber systems from less than one to as high
as 20 (American Air Filter Company, Inc., 1978). Typical rates of
about 3 gal/min for each 1000 cfm of gas flow have been reported for
venturi scrubbers (Danielson, 1973; Soderberg, 1974). On this basis
the typical plant may be assumed to use about 2700 gallons of water
per hour or about 7.56 million gallons in a year's operation as
calculated above. The recycling rate for scrubber water is high.
Based on the assumption that 90 percent or more of the water would be
recycled, annual consumption is about 750,000 gal/plant.
4-40
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CO
4J
S
600
500
2 400
•H
3
cr
-------
1500
100 200
Additional Horsepower Required
FIGURE 4-10
FUEL REQUIREMENT FOR VENTURI SCRUBBERS
4-42
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4.6 Environmental Effects of NSPS
4.6.1 Estimated Particulate Reduction
Prior to promulgation of current NSPS for smelters, EPA (1973)
estimated that the secondary lead industry was approximately 90 per-
cent controlled. On this basis the particulate output of an average
plant may be estimated as 10 percent of the uncontrolled rate. Uncon-
trolled emission rates in Table 4-3 are based on pounds per ton of
metal charged to the furnace. Using an average figure of 70 percent
lead product recovered from the metallic input, these values have been
adjusted (as used in Table 4-8) to facilitate conversion to annual
output through use of average rates. It was assumed that each new
plant would produce on the average 6000 tons of lead per year (a
slightly higher figure than the 1975 average obtained from Bureau of
TABLE 4-8
ESTIMATED ANNUAL REDUCTION OF PARTICULATES FROM NSPS
Blast Reverberatory
Furnace Furnace
Average particulate emissions
per plant (Ib/ton of product)3
276
210
Without NSPS (90% control)
With NSPS (99.3% control)
Net reduction per plant
(Ib/ton of product)
Annual average reduction
per plant (tons)
28
2
26
78
21
1
20
60
aSingle value rates as estimated by EPA (1975) multiplied by 1.43
to convert Ib/ton of lead product.
4-43
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Mines statistics). A conservative estimate of 99.3 percent
efficiency was used to calculate particulate emissions under NSPS. It
was further assumed that all lead would require smelting in either a
blast or reverberatory furnace with any refining or alloying in pot
furnaces additional. (Pot furnaces have negligible emissions and are
not subject to particulate control under NSPS rates on an uncontrolled
basis.)
As shown in Table 4-8, the average annual reduction per plant is
78 tons of particulates for blast furnaces and 60 tons for reverbera-
tory furnaces. Assuming an approximately equal mix between the two
figures and rounding off the average value to 70 tons annually, the
average can be applied to the number of plants coming under NSPS in
any one year. The EPA (1973) estimate of 2 plants coming on line
each year results in a value of 140 tons of emission reduction. This
figure estimates the reduction in any one year from new and modified
plants subject to NSPS. If a constant growth rate is assumed for each
of the 4 years during which the NSPS have been in effect, the total
reduction would be 10 times this figure or nearly 1,400 tons of
particulates.
4.6.2 Estimated Reduction in Lead Emissions
The secondary lead industry is not one of the prime sources of
lead emissions; its annual output is estimated to be only about one-
third that of primary production of lead. In total tons of lead
Future plants are likely to be about twice as large, so that annual
reductions for 1978 and later may be double those shown in Table 4-8.
4-44
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emitted, the secondary smelting industry ranks behind copper, various
iron and steel processes, gasoline additives, oil-fired utilities and
municipal incinerators. A survey of plants that produced approxi-
mately 90 percent of all secondary lead in 1970 showed an average
factor of lead emissions to the atmosphere of 0.7 Ib/ton of product
/
(Davis, 1973; MITRE Corporation, 1977).
Quantitative data are limited on Che emission rate of lead from
control systems meeting NSPS for particulates from secondary lead
smelters. Limited test data from seven furnaces cited in Section
4.4.1 indicate that baghouses and/or venturi scrubbers may reduce the
rate of output (from the overall industry average of 0.7 Ib/ton) by
one to two orders of magnitude. Lead emissions reported from the
plants tested ranged from about 0.009 to 0.0846 Ib/ton; five of the
tests resulted in emissions below 0.04 Ib/ton (EPA, 1973). Using the
figure of 0.05 Ib/ton as a conservative estimate,* the reductions in
lead emissions attributable to NSPS may be calculated for plants
subject to these standards in the same way as was done for
particulates in the preceding section. The results are summarized in
Table 4-9.
The figures in Table 4-9 do not coincide with results that would
be obtained by applying to the estimates of reduced particulate emis-
sions (as given in Table 4-8) factors for the average concentra-
tion of lead particles. On the basis of 23 percent lead content of
*This estimate correlates well with that obtained from EPA (1977)
estimates of 99.92 efficiency for capture of lead emissions with
baghouses as considered in Section 6.3.
4-45
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TABLE 4-9
ESTIMATED TOTAL REDUCTIONS IN LEAD EMISSIONS FROM NSPS
Average emissions per plant
Uncontrolled 53-56 Ib/ton
Without NSPS 0.70 Ib/ton
With NSPS 0.05 Ib/ton
Net reduction 0.65 Ib/ton
Average annual reduction per plant 3900 lb/1.95 tons
Annual reduction for plants
newly subject in 1 yr 27.30 tons
Estimated cumulative reduction
1974 - 1978 273.0 tons
particulate emissions and using the estimates of Table 4-8, the re-
ductions in lead emissions would increase by a factor of about eight
over the results shown in Table 4-9. Several explanations for the
discrepancy are possible:
• The degree of particulate control in the absence of NSPS as-
sumed for the secondary lead industry is too low, so that the
net reduction in particulate emissions is overestimated in
Table 4-8.
• The estimate of 23 percent lead in uncontrolled particulate
emissions does not apply to the outlet of a control system,
which actually traps a disproportionately high amount of
lead-bearing particles.
• The average of 0.7 Ib of lead emitted per ton of product
is inaccurate for the secondary lead industry as a whole so
that the lead emissions in the absence of NSPS are actually
higher than reported. Comparing the value of 0.7 Ib/ton with
the estimate of uncontrolled lead emissions on the basis of 23
percent of particulates or about 55 Ib of lead per ton of
product implies an efficiency of about 98 percent in control
of lead.
4-46
-------
In the absence of more definitive data, particularly on lead em-
ission rates both controlled and uncontrolled (discussed further in
Section 6), the inconsistency cannot be resolved.
4-47
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5.0 INDICATIONS FROM TEST RESULTS
5.1 Test Coverage in Regions
MITRE/Metrek surveyed secondary lead smelters in the 10 EPA
regions to obtain NSPS compliance data and emission control tech-
nology information (Table 5-1). Results of one test from Region II
and three tests from Region IV were made available. No compliance
data were available from the other regions. A few other tests were
conducted, but reports were not supplied.
All tests were found to be in compliance with the particu-
late standard. Two of these tests (Region IV) were also found to be
in compliance with the opacity standard. Test results for opacity
were not reported from the other plants.
The process equipment affected by the standards varied among the
plants tested. The plant tested in Region II reported a facility
subject to NSPS consisting of three pot furnaces exhausting through
one stack. Region IV reported process equipment that consisted of a
reverberatory furnace at one plant and a blast furnace at another.
Furnace type for the third was not reported. Whether the plants
tested were new or modified sources is unknown.
Control technology for the pot furnaces in the plant in Region
II is unknown. The technology for the reverberatory furnace in
Region IV was reported to be afterburners and a melting chamber;*
the technology for the other furnaces was reported to be a baghouse.
At this time (December 1978), clarification of this surprising
report has not been provided.
5-1
-------
TABLE 5-1
MITRE/METREK SURVEY OF NSPS TEST DATA FROM REGIONS II AND IVa
Region and
Test No.
Pollutants
Process
Equipment
Particulates
(gr/dscf)
Opacity
(%)
Control
Technology
Ol
N>
IV-13
IV-2a
IV-3b
3 pot furnaces 0.0013
exhausting through
one stack
Reverberatory 0.015
furnace
Blast furnaces 0.0135
Unknown 0.0106
<10
0
Unknown
Afterburners,
melting chamber
Baghouse
Baghouse
aNo tests submitted from the other eight regions. MITRE Corporation, 1978.
bEPA, 1979.
-------
5.2 Test Data
Available test data are too limited to be considered as adding
anything new to results reported prior to promulgation of NSPS. The
relevant tests (pot furnaces are not subject to control of particu-
lates under NSPS) should be considered as three more data points that
may be added to the nine tests conducted by EPA and the Los Angeles
County Pollution District. In all of these tests reported for plants
controlled by baghouses and/or venturi scrubbers, particulate emis-
sions averaged less than 0.022 gr/dcsf (EPA, 1973; Engineering-
Science, Inc., 1977).
5-3
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6.0 ANALYSIS OF POSSIBLE REVISIONS TO NSPS
6.1 Industry Trends
General trends of the secondary lead industry discussed in Sec-
tion 4 included the gradual rise in annual output, increased secondary
lead production with a decrease in the number of plants, and changes
in the pattern of lead consumption. An important technologic develop-
ment is the emergence of a new battery for vehicles which is relative-
ly maintenance free. This battery requires lead alloyed with only
one-half to one-third the antimony content previously used. A higher
heat rate is applied in resmelting the scrap batteries and in produc-
ing a lead that is virtually free of antimony. As a result, the quan-
tity of vapors and particulates emitted from the furnace with a given
charge of material may be increased, although quantitative data on the
effects are lacking. The development of secondary lead with very high
purity tends to increase interchangeability between the recycled metal
and that produced from virgin ore. In some instances, secondary lead
is produced that is purer than the primary product. The competitive
position of secondary lead is apparently becoming stronger, although
the relative share of the market remains near the 50 percent level
subject to minor fluctuations each year (Bureau of Mines, 1978).
The real price of lead has been decreasing steadily since 1950.
In terms of constant 1976 dollars, Jzhe price has declined by about 27
percent since 1954 and about 10 percent between 1974 and 1976. Thus,
the profit margin or net annual income of the industry as a whole is
6-1
-------
continuing to decrease at a time when heavy costs are being required
to control pollutants. In production of primary lead, capital expen-
ditures have been particularly high (Bureau of Mines, 1977; 1978).
Thus, it appears that pollution control has not degraded the competi-
tive position of secondary lead.
Production of lead from both primary and secondary sources is
expected to grow by about 50 percent between 1976 and 2000. Changes
in demand patterns including attrition of the tetraethyl lead market
and the substitution of other materials for such uses as paints, cable
covering, calking, and some types of containers are expected to slow
the rate of, but not prevent increases in, lead production. Average
annual increase in demand for lead from 1967 to 1976 was about 3 per-
cent. A 50 percent increase by 2000 implies an annual growth rate of
slightly under 2 percent. Bureau of Mines figures project that the
demand for lead in the year 2000 will be from 1.08 to 2.46 times the
1976 consumption of about 1.5 million tons. An estimated total demand
of 2.33 million tons is deemed by the Bureau of Mines to be the most
probable projection. The demand for lead in gasoline additives is
projected to decrease to about one-third of its 1976 level, although a
decrease by a factor of as much as six is possible. Attrition of this
market is expected to be compensated by varying increases in all other
end uses. Demand for lead for other transportation purposes is
expected to more than double. The fraction of the market represented
by use of lead in paints and for electrical purposes will increase
6-2
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about 20 percent over that in 1976. End uses for other construction
purposes, in ammunition, and for miscellaneous products are seen as
changing less than 1 percent from their respective 1976 market per-
centages (Fine et al., 1973; Bureau of Mines, 1977).
6.2 Review of Current NSPS
Little substantive data on current NSPS for opacity and particu-
lates from secondary lead smelters can be added to that reported by
EPA (1973) at the time the standards were proposed. Standards of
0.022 gr/dscf for particulate emissions and 20 percent or less in
opacity (10 percent for pot furnaces) are being met. No failure in
meeting standards has been reported in information available to the
present study. Hence, there is no basis for relaxing these standards.
Test results after 1973 are too limited to provide any foundation
•
for inference as to whether efficiency of control systems has improved
enough to support more stringent standards. Fabric filters and high-
efficiency venturi scrubbers still represent best technologic system
of control. Examination of estimated inlet loadings to collector sys-
tems indicates that control efficiencies well in excess of 99.5 per-
cent are required. Efficiencies in this range are reported in the
literature, and EPA (1977) has estimated overall collection efficien-
cies of 99.91 and 99.09 percent from the front half and the total
train, respectively, for secondary .lead blast furnaces equipped with
baghouses. Specific test data are, however, lacking by which to fix
the performance of control systems over the range of operating
6-3
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conditions that may be encountered and, hence, to support a basis for
a more stringent level of control for particulate emissions.
In regard to opacity, less quantitative data are available than
for particulates. It is known that optical transmittance can range
widely in relation to mass concentration of particulate matter. On
physical grounds and from analogy with industries where more test data
exist, one might conjecture that an opacity reading of considerably
less than 20 percent be associated with the NSPS for particulates of
0.022 gr/dscf.
6.3 Lead
6.3.1 Emission Rates
EPA (1975) estimates the uncontrolled emission rate for lead
from blast and reverberatory furnaces as 56 and 53 Ib/ton of product,
respectively, or about 23 percent of the particulate emissions. Some-
what higher rates were reported in a recent study (details are not yet
available) and the issue remains in doubt. These are high per unit
when compared with storage battery manufacturing (17.7 kg/1000 batter-
ies), lead glass (15 Ib/ton of product), iron and steel production,
and various processes that account for high percentages of annual lead
emissions as tabulated by EPA (1977). However, EPA estimates the
secondary lead industry to be about 95 percent controlled and the 1975
total output of lead emissions from secondary smelters to be about 830
tons. This compares with over 18,000 tons expected at the uncon-
trolled rate from the production of 658,500 tons of secondary lead in
1975.
6-4
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6.3.2 Control Effectiveness
Controls for lead from secondary furnaces are the same as those
for particulates. The technique consists of capturing the lead-
bearing particles in a baghouse or removing them in a high efficiency
wet scrubber. EPA deems the baghouse to be the most effective control
technique and estimates its efficiency in removing lead emissions to
be as high as 99.92 percent, based on total-train sampling. This
estimate would give a controlled emission rate of about 0.0448 Ib/ton
of lead, or an emission rate of 2.24 Ib/day for a typical 50 ton/day
plant. The average plant production rate of about 6000 tons annually
would result in about 270 Ib/yr, or about 0.13 tons/year.
The important question in regard to control of lead emissions is
whether the lead is captured in the form of lead-bearing particles at
the same rate as particulates generally or whether higher fractions of
the lead escape as smaller particles or possibly in vaporized form.
If the captured particles contain 23 percent lead (i.e., the same per-
centage as estimated for uncontrolled emissions) then a 50 ton/day
plant meeting the particulate standards at 0.022 gr/dscf would release
about 2.8 Ib/hr of particulates (based on a flow rate of 15,000 dscf)
of which the lead content would be (at 23 percent) about 0.65 Ib/hr or
slightly over 0.3 Ib/ton.
Results in control of lead emissions were recently reported by
the Chicago Department of Environmental Control (Petkus et al., 1974).
A survey of 11 controlled smelters producing some 6600 tons of lead in
6-5
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a year revealed lead emissions at the rate of approximately 1 Ib/mil-
lion Ib (500 tons) of product (controlled emission rate of 0.002 lb/
ton of product).
Very little basic data from tests on controlled lead emission
rates are available. However, six tests conducted before 1973 showed
lead emissions from plants controlled by baghouses and/or venturi
scrubbers to be slightly less than 23 percent of the particulate rate
or about 19 percent on the average.
Sublimation of lead particles might be conjectured at the very
high temperatures at which the stack gas leaves the reverberatory
furnace (up to 1350°F) or in the afterburner of the blast furnace.
However, gas must be cooled to 500°F or less before entering a bag-
house to avoid damage to the filter fabric. With venturi scrubbers,
the water quench necessarily succeeds also in reducing the tempera-
ture of the gas. Thus, the likelihood of vaporized lead escaping a
control system is much less than the likelihood of sublimation within
a furnace or afterburner. Such particles escaping the collector would
tend to be smaller than 1 micron.
No test data exist for comparing baghouse content of lead with
the results of Method 5 tests of emissions from fabric filters. No
materials balance is thus possible to account comprehensively for
where lead emissions from the smelting furnaces finally appear.
Available evidence is consistent, however, in indicating that the
ratio of lead to particulate emissions from controlled furnaces is no
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higher than the ratio for uncontrolled rates (23 percent). Further,
the estimate of 0.0448 Ib/ton of product based on 99.92 percent bag-
house efficiency appears as a reasonable, and even conservative, es-
timate for a well-controlled furnace.
Ambient standards for lead have now been promulgated by EPA.
Based on modeling results, EPA has estimated (Scruggs, 1977) that for
each ton of lead product, the lead concentration nearby will be 8.69 x
10~5 |j.g/in3. The maximum downwind concentration average over a
year was estimated to be about 0.0105 fig/or for each ton of lead em-
itted by a plant. Although much higher values have been recorded near
secondary smelters, they are unlikely to be observed as a result of
stack emissions from well-controlled furnaces. Tests near a smelter
in Texas at a range of about 60 to 300 meters distant showed air con-
centrations from 3.3 (Jig/m^ to as high as 11.6 p-g/m^ (Texas Air
Control Board, 1974). Data are not available as to the degree of
control practiced at this site. Roberts et al. (1974) report lead
concentrations in suspended particles at about 200 m from two Canadian
smelters in the range from 1 to 5.3 fjig/m^. These two Canadian
furnaces were estimated to have emitted over 33,000 and 66,000 Ib of
lead per year. Such lead emissions are more than two orders of mag-
nitude greater than estimates previously noted for stack emissions
from an average 6000 tons of lead per year furnace; they would not be
approached by well-controlled furnaces of much greater capacity.
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Figure 6-1 shows the estimated maximum downwind concentrations
from the typical 50 ton/day furnace and the distances at which these
would be experienced for different meteorological stability condi-
tions as established from calculations by the U.S. Public Health
Service (Turner, 1969). Results are based on a 3-minute sampling
time. These results will vary with topographic and architectural
conditions that prevail at specific furnace locations. However,
T
levels of 2 [ag/m would be expected from the estimated emission rate
for a controlled 50 ton/day furnace only under exceptional windspeed
conditions. With production and output rates up to four times
greater, maximum concentrations of 2 u.g/nr* would not be expected
even with moderate wind conditions of 4 m/s (about 8 knots) or
greater. For a 24-hour average, the estimated level decreases to 36
percent of the 3-minute sampling value (shown in Figure 6-1). Thus, a
3-minute level of 5.56 [ig/m^ corresponds to a 24-hour average of
2 ng/m3-
6.3.3 Fugitive Emissions
Besides the material discharged through the stack of a secondary
lead furnace, smoke and dust particles may be emitted into the atmos-
phere in and around a plant from other operations. Some of these
emissions may be process-related, e.g., when fumes escape from the
hoods provided around potential outlet points of a furnace. Others,
which may be termed site related, result from auxiliary operations
outside the plant. The term fugitive emissions is often limited to
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vo
Wind Speed » 1 m/s QL--
Maximum Ground-Level Concentration (jjtg/m )
II I I 1 I I II I I I I I I I IH I II
Wind Speed = 2 m/s
Wind Speed = 4 m/s
Source: Turner, 1969.
.2 .3.4.5
I I I
1 2345 10 20 30 40
I I HI I I I I I I MM I
.05 0.1 0.2 0.3 0.5 1
II II I I III I I I I I
345 10 20
1 i I I I I 1 III
.03' .05 0.1 0.2 0.3 0.5
3 4<5
10
FIGURE 6-1
MAXIMUM GROUND-LEVEL CONCENTRATION OF LEAD PARTICLES
IN AIR AND DISTANCE FROM STACK
-------
process-related emissions, but usage in the literature is divided,
with some writers applying the term both to smoke and fumes escaping
from the smelting process and to windblown dust from storage and hand-
ling procedures. The important point is that both potential sources
can contribute significantly to pollution. Both will be discussed in
the present section on fugitive emissions with a distinction made
between process- and site-related emissions.
No fugitive emission points, whether related to processing or to
auxiliary operations at the site, are currently subject to specific
control under NSPS for secondary lead smelters. In some situations,
fugitive emissions may be high. The high concentration of lead, par-
ticularly in the soil, close to two Toronto smelters was largely
ascribed by Canadian investigators to "low-level, dust-producing oper-
ations rather than. . .stack fumes" (Roberts et al., 1974). In ex-
treme situations, fugitive particulate emissions from processing may
amount to over 15 Ib/ton of charge from reverberatory furnaces and as
much as 12 Ib/ton from blast furnaces. While these rates are much
lower than uncontrolled emission rates from furnace stacks, they are
also substantially higher than rates achieved under NSPS controls.
Lead and iron scrap burning may produce from 1 to 2 Ib/ton of scrap.
Other potential sources include storage, loading and transfer of
material, as well as handling of dust collected by control systems
(EPA, 1977). It is reportedly common for baghouse catches to be
stored in open piles at a plant yard until enough material has
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accumulated for charging to a reverberatory furnace (EPA, 1978b).
Experimental data are lacking on the extent to which fugitive emis-
sions at secondary lead smelters subject to NSPS control actually
occur, either from process-related operations or from auxiliary opera-
tions at the site. On the one hand, several factors would be expected
to minimize such emissions at well-regulated plants.
Hooding of all points of potential emissions in the smelting
process and venting of the air to the control system along with gas
from the furnace is intended to prevent significant escape of lead
particles or other particulate matter from the collector device. It
is in the economic interests of an owner/operator to prevent fugitive
emissions during smelting to avoid loss of fines valuable for their
lead content, as well as to protect worker health and efficiency. The
sound engineering practices dictated by these considerations to pre-
vent such fugitive emissions are prescribed in regulations of the
Occupational Health and Safety Administration, which note specifically
the need for enclosing potential sources by hooding. Accidental leaks
in hooding and ventlines can be minimized by adequate maintenance
practice.
However, several variables can affect the discharge of fugitive
emissions during smelting and can negate preventive measures. These
include process aberrations, differences in raw materials, and varia-
tions in operating parameters such as blast air rates. Data on the
effects of these variables are not available. Where particulates
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escape into the plant area adjacent to the smelting operation, some
release to the outside is almost inevitable as a result of normal
ingress and egress. Monitoring of the atmosphere adjacent to second-
ary lead smelters has on occasion uncovered unacceptable concentra-
tions of lead which may reflect fugitive emissions. At least one
instance has been reported in which a smelter was required to be
sealed, with all air inside the plant vented to the control system
(EPA, 1978).
The role of fugitive emissions in the high lead concentrations
observed near Texas smelters (previously cited in Section 6.3.2) is
unknown. The relative contributions of process- and site-related
sources are also unknown for the lead levels in the atmosphere and
soil as reported in the Canadian investigations. Assuming that con-
trol of fugitive emissions through hooding and venting to the control
system achieves a level of reduction over uncontrolled emissions
which is comparable to that provided for furnace gas, less than 0.01
Ib of particulates/ton of lead product would be expected from proces-
sing operations, or a maximum of about 60 Ib/yr for each plant. How-
ever, data from tests and observations on which to confirm or modify
this assumption are not available.
Significant improvements in the technology of controlling fugi-
tive emissions from both process- and site-related operations in sec-
ondary smelting of lead have recently been reported in Denmark. The
methodology uses improved furnaces that minimize the escape of dusts
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during smelting and also enable baghouse contents to be recharged as
collected, thereby eliminating the accumulation of these fines in
storage piles where they are subject to transport into the environ-
ment. Specialized waste management and housekeeping procedures are
used in conjunction with the furnaces to reduce the opportunity for
emissions from storage of raw materials and other sources on site.
The technology has been investigated by the EPA Industrial Environ-
mental Research Laboratory in Cincinnati in connection with the
National Institute of Occupational Safety and Health (NIOSH). Test-
ing of the furnaces has been conducted under the joint auspices of EPA
and NIOSH at a plant in Denmark. Initial reports indicate the tech-
nology as having high potential for application in reducing fugitive
emissions from secondary lead smelters in the U.S. (EPA, 1978d).
6.4 Sulfur Dioxide
6.4.1 Emission Rates
The rate of uncontrolled emissions of S02 from secondary lead
smelters has been estimated by EPA (1975) to be approximately half
that of particulates. While the estimated rates of 76 Ib/ton of lead
produced for blast furnaces and of 114 Ib/ton for reverberatory fur-
naces* are low in comparison with emission rates from primary pro-
duction of metals, they are more than twice the rates of regenerative
furnaces used in manufacturing fibeg: glass and compare with the
*These values represent adjustments of the EPA estimates so as to
reflect pounds per ton of lead product (assuming 70 percent
recovery) instead of per ton of metal charged.
6-13
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uncontrolled emission rates of sulfuric acid plants. Comparative
costs for controls in some selected industries are considered in a
later section.
Currently, no NSPS for SC>2 from secondary lead smelters are in
effect. A reverberatory furnace of 50 tons/day (2.08 tons/hr) would
emit about 2.85 tons of SC-2 each day and a blast furnace of the
same capacity about 1.9 tons. Assuming an equal mix between blast
and reverberatory furnace production, the total secondary lead pro-
duction in 1975 of 658,500 tons would have resulted in about 31,000
tons of S02- This is about one-tenth of 1 percent of the total
SC-2 emissions from stationary sources (which comprised 98 percent
of the national emissions) in 1972 and the same percentage of 1975
emissions as estimated from modeling techniques by the Argonne
National Laboratory (Habegger et al., 1976). This study has further
estimated that by 1985 SC>2 emissions from secondary lead reverbera-
tory furnaces will amount to about 29,000 tons. This estimate may be
compared with estimates similarly derived from other source categor-
ies as shown in Table 6-1. Overall, this study has ranked lead
reverberatory furnaces as fifteenth out of approximately 30 source
categories on a priority basis for consideration of controls by EPA.
A wide range of SC>2 concentrations from secondary lead smel-
ters depends not only on the amount of sulfur in the charge but also
on production rates and flow rates of exit gas. These ranges are
shown in Figure 6-2. A 50 ton/day blast furnace with a flow rate of
6-14
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TABLE 6-1
ESTIMATED TOTAL S02 EMISSION
IN 1985 FROM SELECTED SOURCE CATEGORIES
Category3 Thousands of tons/yr
1985
Boilers (>250 x 106 Btu/lb) 8352
Smaller boilers 4445
Portland cement 335
Petroleum refinery (fluid catalytic
cracking unit) 259
Wood pulping 164
Stationary gas turbines 125
Incinerators 63
Iron and steel 54
Glass (soda lime glass) 36
Secondary lead, (reverberatory
furnace) 29
Sulfuric acid 23
aPrimary metal production is not included; greatly reduced
emissions are anticipated under existing NSPS.
Source: Habegger et al., 1976.
6-15
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T
H*
0\
1300
100
20 40 60
100 200
S02 Emission Rate (Ib/hr)
FIGURE 6-2
UNCONTROLLED SO2 EMISSIONS
300
-------
15,000 dscfm emitting 802 at a rate of 158 Ib/hr would provide an
uncontrolled concentration of about 987 ppm on a dry basis. For a
reverberatory furnace of the same capacity, the uncontrolled concen-
tration would be more than 1400 ppm. These concentrations would be
reduced for higher flow rates as seen in the figure. Much variation
is also shown in the limited test results available. In eight tests
conducted on secondary lead smelters equipped with baghouses and/or
venturi scrubbers the S(>2 concentrations ranged from less than 0.1
ppm to over 2000 ppm (EPA, 1973).
6.4.2 Resulting SO? Concentrations
An important consideration in regard to S02 emissions from
secondary lead smelters is the concentration that can be expected to
result, particularly at ground level. Results of calculations made
on the basis of hourly 802 emissions are plotted in Figure 6-3.
This figure plots the maximum ground-level concentration of 802 on
the horizontal axis for selected wind speeds and emission rates as
plotted on the vertical axis. Separate graphs are plotted for dif-
ferent meteorological conditions (A, B and D) which are convention-
ally distinguished. Effective stack heights (in meters) of the
discharge are indicated on each graph. The computations in Figure
6-3 were based on the "Workbook of Atmospheric Dispersion Estimates"
(Turner, 1969). For convenience, the output of 802 Per nour is
shown in pounds, but the downwind maximum ground-level concentration
(3-hr average) is shown in micrograms per cubic meter. The secondary
6-17
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-------
level of 1200 [ig/m for a 3-hr average has been set as a value not
to be exceeded more than once per year.
It can be seen from Figure 6-3 that a downwind concentration re-
sulting from an emission rate of 100 Ib/hr would exceed 1000 [ig/m^
only for relatively unfavorable meteorologic conditions and a rela-
tively low effective stack height (e.g., Condition A and wind speed
of no more than 2 m/s or about 4 knots maximum at a stack height of
30 m). Average height of stacks discharging from a secondary lead
smelter is about 150 ft or 40 m (EPA, 1973). The effective height is
somewhat greater, depending on the furnaces. For a relatively neu-
tral set of conditions as represented by Condition D with wind speed
of only 2 m/s, a furnace emitting 200 Ib of S02/hr would not pro-
duce a maximum downwind concentration (on a 3-hr basis) of as much as
1000
6.4.3 Control Technology
6.4.3.1 Methods. Available techniques for removing S02 from
gas exiting a secondary lead furnace consist essentially of contac-
ting the gas with liquid containing an alkaline reagent in the form
of a slurry or in solution as a clear liquor. Through chemical reac
tion the sulfur compounds in the gas are precipitated as sulfites or
sulfates in sludge. In most processes this sludge is a waste that
must be discarded. However, in regenerative processes, the sorbent
is recycled to provide for recovery of marketable sulfur products.
In control of 802 from the primary metals industry, the smelting of
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lead, copper or other ores is often combined with a plant in which
sulfur compounds from a regenerative control process are used to
produce sulfuric acid.
The process of S(>2 removal is often referred to as flue gas
desulfurization. A number of techniques are commercially available
or in pilot plant operation. Much of the developmental work and many
of the applications are for desulfurization of gas from boilers fired
by fossil fuels. Lime and limestone are among the most commonly used
reagents, but other chemical compounds such as magnesium oxide or
ammonia may be used. The so-called double alkali or soda lime pro-
cess employs a combination of sodium carbonate and lime or limestone.
Scrubbing equipment may involve towers or columns packed with
absorbent material over which the gas to be cleaned and the scrubbing
liquid pass, or in which the gas is dispersed through liquid in a
series of trays or plates. Spray towers may also be used, with the
liquid absorbent sprayed through nozzles. Venturi scrubbers are
employed to remove both particulate matter and SC>2 from the gas,
often in combination with some device such as a spray tower or after
absorber, or the gas may circulate in two or more stages within the
scrubber with additional reagent being added at each stage. In a
broad sense, a system for scrubbing S02 from furnace gas may be
thought of as an extension of the venturi devices and similar wet
collectors employed by secondary lead smelters for particulate
control. A single-stage venturi scrubber, such as commonly used in
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lead furnaces to remove particulates, in which lime or limestone is
employed as the slurry, can be counted on in application to utility
boilers to remove about 40 to 50 percent of the 802 (Bechtel,
1978). Typically, two or more stages are necessary to meet S02
emission standards for fossil-fuel fired boilers. Tests of a proto-
type double alkali system employing a combined venturi/absorber con-
figuration reportedly produced removal efficiencies greater than 95
percent when the bled liquor pH exceeded 5.2 and achieved efficien-
cies above 98 percent when pH of the venturi liquor was raised above
6.0 (PEDCo, 1977b).
A few remarkably low 802 emission rates have been reported
from tests of secondary lead furnaces controlled by scrubbers denoted
only as venturi (i.e., without stipulation of the number of stages or
the characteristics of the chemical reagent). EPA (1977) has noted
that a scrubber for particulates provides an advantage in that it may
be designed for 802 reduction. It is not considered, however, that
a scrubber designed for particulate removal could regularly meet any
NSPS for control of S02 emissions from lead smelters. While some
improvement in efficiency of 802 removal has been suggested for
single-stage venturi scrubbers through adjustment in operating condi-
tions (e.g., addition of magnesium oxide to a lime/limestone slurry
to improve its desulfurization properties), further analysis of con-
trol requirements and their costs is based on assumption of a scrub-
ber specifically designed for 802 control. Such a device might be
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added to a system for removing particulates or it might be a subsys-
tem controlling both S02 and particulates.
6.4.3.2 Cost Estimates. A scrubber for 862 removal can be
very costly as an add-on to a baghouse. One reported test involved a
secondary smelter in which a scrubber, representing an investment of
about $700,000, reduced S02 output from about 1800 to 140 ppm (about
90 percent control) (Los Angeles County, 1978). On this basis a sep-
arate scrubber and baghouse for discrete control of S02 and partic-
ulates would approximately double capital costs. The general proce-
dure, however, would be to install a special system designed for
simultaneous removal of both pollutants. Several firms supplying con-
trol equipment were contacted for cost estimates. Secondary lead
smelters do not regularly use scrubbers for reduction of S02 emis-
sions, at least not to the same degree as controls for trapping par-
ticulates (EPA, 1978). Industrial representatives were reluctant to
supply cost estimates applicable to lead furnaces. When experience of
the firm was in S02 control of fossil-fueled boilers, difficulty was
expressed in using costs based on kilowatt capacity of a power plant
or heat-input rate of an industrial boiler to estimate costs for
secondary lead furnaces of the size modeled by EPA (1977) at 50 tons/
day with exit rates of furnace gas in the range of 32,000 to 33,500
ACFM. However, a few spokesmen supplied data varying in amounts and
in level of detail which indicate industrial capability to provide a
combined unit for simultaneous removal of both particulates and 802*
6-22
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Direct comparison between costs of combined systems and those
used only for particulate removal is difficult because of varying
estimates which may not include all of the same items. Estimates
must be general because they apply to hypothetical plants with unspe-
cified design parameters; thus, only an approximation or a range of
values can be indicated. Within these limitations, evidence shows
that the capitalization costs of a combined system are about 10 to 20
percent higher than those of a scrubber installed to control only
particulates.
Based on manufacturer estimates, capital costs of a combined
system for a 50 ton/day secondary lead furnace fall between $500,000
and $1 million. These costs include installation, instrumentation,
all materials, equipment for sludge handling, engineering, training
in usage, and start-up. They are from 25 to more than 50 percent
higher for blast furnaces than for reverberatory furnaces. Taking
$750,000 as the midpoint of the range for a reverberatory furnace and
$1 million for a blast furnace, comparison with EPA (1978) estimates
for particulate controls with a venturi scrubber of $669,000 and
$895,000, respectively, indicates increases of about 11 percent.
This relationship correlates with the estimate of one firm (based on
applications to plants generating electric power) for scrubber costs
designed to remove particulates only and those for combined removal
of particulates and S(>2» These cost estimates are for installation
made at the time of plant construction.
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These estimates may be compared with those in a recent study of
costs of controlling S02 and particulates in coal-fired boilers
used by power plants (PEDCo, 1978). Computerized modeling techniques
were used to calculate costs of several S02 control systems (with
particulate removal) for power plants of different capacity under
scenarios reflecting the type of coal burned and pecentage of S02
removal from flue gas. Although the data were developed specifically
for coal-fired utility boilers, from the parametric assumptions re-
garding flow rates and S02 output, it is possible to draw analogies
with control of secondary lead smelters.
In particular, it may be of interest to compare the inferences
of this study as to the increase in capitalization costs resulting
specifically from components designed to reduce S02« It was found
that the study of costs for power plants produced somewhat higher
estimates than the above-cited figures, both for capitalization re-
quirements and increases due to SC>2 control. Assuming that costing
of heat exchangers, fans and motors, and valves and ducting reflected
requirements for particulate removal as well as S02 reduction,
equipment specific to S02 control was calculated to increase direct
costs (all installed equipment, plus sludge pond) by over 55 percent.
Total cost increases ascribed to S02 removal were from about one-
fourth to one-third, depending upon what items of indirect cost
necessary to a power plant are also judged applicable for secondary
lead furnaces.
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Direct costs were estimated to be about $1,1 million. Total
costs ranged from about $1.4 to under $2 million, again depending on
what indirect costs used by the model were included. These estimates
were obtained by equating a 50 ton/day secondary lead furnace burning
0.8 percent sulfur coal to a 9-MW power plant, on the basis of flow
rate of exit gas and rate of S(>2 output. Costs in dollars per
kilowatt as calculated in the model methodology for the scenario of 90
percent 862 reduction by use of lime scrubbing were then applied to
arrive at rough approximations applicable to the secondary lead
smelter.
Annual operating and maintenance costs for scrubbers have been
estimated to range from 8 to 18 percent of total capital investment
with 13 percent as an average figure, although very high costs of up
to 40 percent are noted (Kinkley and Neveril, 1976). In modeling of
costs for scrubbing and absorption systems to remove particulates as
well as S02 from flue gas emitted by coal-fired boilers used in
generating power, operating and maintenance (O&M) costs were esti-
mated to run 16 to 18 percent of capitalization costs (PEDCo, 1978).
The range of 13 to 16 percent is consistent with results reported in
operation of one manufacturer's equipment with particulate and 802
control of flue gas (Ferb and Stevens, 1978; Research-Cottrell, Inc.,
1978). Fixed annualized costs representing about 20 percent of the
total capitalization requirements have been used by EPA (1977).
6-25
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Thus, 35 percent of the total capital investment representing the
sum of the O&M and fixed costs, may be used as a factor to estimate
total annualized costs of a combined system for venturi scrubbers
controlling particulates only. On this basis, costs for a blast
furnace would be about $350,000/yr and $262,500 for a reverberatory
furnace. It is not clear whether the same credit would apply for
recycled lead from the sludge of a venturi scrubber designed to remove
particulates only as would apply to that produced by the combined
system. If the value of recycled lead is taken at $75,000/yr, annual
costs would be reduced to $275,000 for a blast furnace and $187,500
for a reverberatory furnace. Based on the assumption made in regard
to recycling, at an average output of 6875 tons, price per ton of lead
product would be increased by an amount between $27.27 and $38.18 for
a reverberatory furnace and between $40 and $50.90 for a blast fur-
nace. These estimates compare with increases in cost of $22 and $33
per ton resulting from use of a venturi scrubber to control particu-
lates alone.
6.4.3.3 Estimated Costs per Ton Captured. An important con-
sideration in regard to the possibility of NSPS for control of S(>2
emissions from secondary lead furnaces is the cost per ton of S(>2
captured. Such costs may differ by more than an order of magnitude
when compared with other industries; for example, about $40 to $60/ton
of S02 captured in I^SO^ plants and from around $500 to nearly
$1500 for electric generating utilities, depending on the type of
6-26
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coal burned. It is estimated that in H2SO^ plants reduction of
the uncontrolled rate of 26 to 56 Ib of S(>2 per ton of product to
the maximum permissible level of 4 Ib/ton is achieved at a cost (based
on a 1970 estimate) of $1.05 per ton of I^SO^ produced (Chemical
Construction Corporation, 1970). While this cost may have advanced
substantially since then, even if the increase significantly exceeded
the overall rate of inflation, the per ton cost would still be only a
small fraction of the estimates for removing S(>2 from flue gas of
coal-fixed utilities (EPA, 1978d).
In the secondary lead industry the incremental annualized costs
for combined SC>2 and particulate control over those for particulate
removal alone as primarily calculated are about $35,500 and $49,000,
respectively, for a 50-ton-day reverberating and blast furnace (Table
6-2). On the basis of average uncontrolled emission rates and annual
production, each plant may be estimated to release at present 393 and
260 tons of 802 Per year> respectively. With 80 percent reduction,
the costs per ton of 802 captured would be $113 and $236, respec-
tively.
6.4.3.4 Level of Control. Reduction of S02 in the gas stream
by well over 80 percent is commonly reported in the operation of
lime-based scrubber systems used by coal-fired power plants. How-
ever, in the present context these results must be considered with
some caution until more comprehensive data are available from long-
term operation. The magnesium oxide and double alkali systems are
designed for removal of 90 percent or more 802 ^rom utility plants
6-27
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•n
OS
C
o
•^
CO
en
•H
5
co
cj
120
100
80
60
40
20
100
200 300
400 500
600
S02 Pounds/Hr
2550 100 150 175
1 T/H
CO
O 3 | L
M 84
5 I
O -H
e a
1 - 1 - 1 - 1 - 1
2 T/H
25 50 75 100 125 150
ii i
25
1 L
20
50
i
25
75
i
50
100
i
75
110 125
i
100
150
i
114
j x/ a
i i
125 15
4 T/H
FIGURE 6-4
SO2 EMISSIONS AT
SELECTED CONTROL LEVELS
6-28
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TABLE 6-2
ESTIMATED COSTS OF S02 CONTROL
PER TON CAPTURED
Parameter
Reverberatory
Furnace
(dollars)
Blast
Furnace
(dollars)
Annualized costs, combined
particulate and S02 control
Annualized costs, particulate3
removal alone, with venturi
scrubbers (Table 4-6)
Incremental costs, S02 removal
Average S02 output, Ib/ton
lead product^3
Average annual production,
tons/plant (1975)c
Average uncontrolled S02
187,000
114.29
6,875
275,000
152,000
35,500
226,000
49,000
75.71
6,875
emissions, tons/year
Tons captured at 80% reduction
Average cost/ton captured
393
314
113
260
208
236
aAs discussed in Section 6.4.3.2.
bAdjustment of AP-42 estimates on basis that 70% metal charged is
recovered as lead product.
cBureau of Mines (1976).
6-29
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and have tested at this level in pilot or prototype operation.
Results in this range have been reported among others from the GM
Parma system, the Mystic Station Unit No. 6 at Everett, Massachu-
setts, the Firestone-Potts system, and the Gulf-Scholz prototype
system (PEDCo, 1977; EPA, 1978c). In support of the Background
Information Document for proposed revision of NSPS applicable to
steam-generation of electric power, cost calculations for combined
removal of S02 and particulates were made for scenarios with 80 and
90 percent reduction of S02 (PEDCo, 1978). One manufacturer pro-
ducing combined units for removal of both S02 and particulates sup-
plied a brochure with sample cost calculations (for a coal-burning
utility boiler) on the basis of average S02 removal efficiency of
95 percent (Research-Cottrell, Inc., 1978).
However, these results are based on very limited operation and
represent systems designed to remove 802 from combustion of coal or
high-sulfur fuel oil. Technology transfer would be involved in
applying them to the secondary lead industry and any predictions as
to the success of such transfer could at this time be offered only
with reservations.
The question may be raised regarding efficiency of particulate
removal by such combined systems. Use of venturi scrubbers may be
considered marginal with reverberatory furnaces which emit very fine
particles of less than 0.4 microns and a mean size of 0.3 microns.
6-30
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In the absence of specific data from tests and/or operating exper-
ience with such combined systems for secondary lead furnaces, there is
some risk. An owner who purchased such a system (at a cost from 10 to
25 percent above the price of venturi controls for particulates) and
then found his plant out of compliance with NSPS might face a severe
penalty. If forced to obtain a fabric filter system in addition, the
owner would incur costs essentially double what they would have been
for control of particulates alone. It may be noted, however, that
some combined equipment is designed for such eventualities, by en-
abling improved collection efficiencies to be achieved through higher
fan horsepower to increase the pressure drop (Research-Cottrell, Inc.,
1978).
6.4.4 Potential Impacts of SO? NSPS
6.4.4.1 Environmental Effects. Environmentally, the chief
potential impact of promulgating NSPS for S0£ emissions from second-
ary lead smelters will be the reduction of sulfur oxides discharged.
There will be some increase in energy requirements and fuel con-
sumption for control systems and an undetermined additional solid
waste disposal.
Quantitatively, the estimates of potential environmental impacts
depend on the production rate of plants subject to NSPS. Since this
cannot be determined for a future time or even precisely estimated
from available data, it is necessary to indicate the probable effects
as a range of values. As shown in Table 6-3, the uncontrolled emis-
sions of S(>2 per year from a single plant are estimated to range
6-31
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TABLE 6-3
ESTIMATED REDUCTIONS IN TOTAL ANNUAL
S02 EMISSIONS FROM FUTURE NSPS
Average rate uncontrolled 95
S02 emissions, Ib/ton of
product3
Estimated annual production 6,000 13,000 18,000
of lead per plant, tons
Estimated uncontrolled 285 618 855
annual SC^ emitted
per plant, tons
Tons captured, per 10% 28.5 61.8 85.5
reduction
Tons captured, 80% 228 494 684
reduction
Tons captured, 90% 257 556 770
reduction
aRate obtained as the average of separate estimates for blast and
reverberatory furnaces (see Table 6-2).
6-32
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from under 300 to over 850 tons, depending on assumptions made as to
the plant's annual production. Tons of S02 removal per plant at a
level of 80 percent reduction accordingly vary from 228 to 684 per
year. With an average of from three to four additional plants subject
to NSPS each year, the expected effect would then be to reduce S02
emissions by an additional annual amount of between about 700 and
2,700 tons. At a level of 90 percent captive, an additional amount of
S02 between about 770 and 3,000 tons would be removed each year.
Increased requirements for energy and fuel may be estimated from
the substantially higher pressure drop required in scrubber systems
for jointly controlling S(>2 and particulate emissions over the very
modest requirements for fabric filters. The increased pressure drop
may be conservatively estimated at 50 to 80 inches water gauge with
corresponding horsepower increases of between 200 and 300. To produce
the annual tonnages listed in Table 6-3, plants of about 50,100 and
150 tons/day may be estimated to operate about 2800 hr/yr. On this
basis, an additional 400 to 600 kWh of energy would be required each
year with a Btu equivalence in the range of 4.2 to 6.4 x 10 • The
fuel requirements in terms of barrels of oil average about 1000 bar-
rels/plant anually. This figure represents an infinitesimal increment
to total U.S. oil consumption of over 6.4 billion barrels in 1976 and
is a very small fraction of 1 percent of even the average daily import
of more than 7 million barrels in the same year (Bureau of Mines,
1976).
6-33
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The question of increased disposal of solid waste from NSPS for
S02 from secondary lead smelters is problematical. EPA (1973) ori-
ginally estimated that sludge collected from scrubbers could be dried
and the lead recycled. Data are not available as to how much such
recycling is practiced in the secondary lead industry.
Recycling of scrubber sludge after drying may or may not be
feasible, depending particularly on what reactive agents are used in
the scrubber. Problems with the scale and reduced throughput may
constrain recycling. Most of the dust trapped by fabric filter sys-
tems is reportedly recycled until the dust becomes too contaminated
with lead chloride. At that time, part of the dust is leached or
landfilled (EPA, 1978b). The study of priorities for development of
NSPS for additional stationary sources (Habegger et al., 1976)
regarded control of SC>2 from secondary lead furnances as involving a
trade-off between reduction of atmospheric emissions and aggravation
of the solid waste problem.
In the absence of the necessary specific quantitative data, it
can only be concluded that some fraction of the total amount of sludge
trapped would require disposal as solid wastes. Since it is also not
known what fraction of particulate dust trapped by fabric filter sys-
tems is recycled, quantitative comparison on a dry-weight basis of the
solid waste disposal requirements with and without S0£ control is
not possible. It is likely that the amount recycled from a baghouse
would be substantially higher than that regenerated by drying of
sludge. One factor militating against recycling of sludge dried from
6-3 A
-------
a scrubber that removes 802 is the presence of a high concentration
of sulfur.
6.4.4.2 Potential Economic Effects. The immediate economic
effect of any NSPS for reduction of S02 would be in terms of the
increased cost to secondary lead producers. As noted previously, the
data are incomplete. Compared with the expenses of providing scrub-
bing for particulates only, it appears that an increment of 10 to 20
percent is involved, although increases of up to one-third cannot be
ruled out, based on the modeling methodology employed for coal-fired
utility boilers (PEDCo, 1978). In other words, a plant owner who
faces an increase in annualized costs of $33/ton of product from a
blast furnace for venturi control of particulates might find that
removal of 862 also requires his cost to be $43/ton (30 percent
higher). This difference of $10/ton represents about 2 percent of the
estimated 1978 price of a ton of lead ($534) escalating the 1976 aver-
age value to 1978 prices. Higher percentages would result from
different assumptions about the costs for scrubber systems with and
without 802 reduction specifically built in, but preliminary indica-
tions are that the additional cost for 802 control would be in the
range of 1 to 5 percent of the average price of a ton of lead.
The increased costs may place an inequitable burden on the small
operator. The scale factor for combined scrubber systems is unknown;
The price of lead has increased over the years but at a rate less
than the general inflation rate and less than costs of equipment and
other materials as pointed out in discussing the fact that lead
prices have declined in terms of constant dollars.
6-35
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however, in terms of cost per ton product, it is certain to favor the
large plant.
Besides the effect on the small operator, there are other impor-
tant questions relating to the economic impacts of NSPS for control-
ling SOo from secondary lead smelters. One of these is the extent
to which additional costs can be passed on to the consumer. Limited
evidence suggests that no significant shift in demand would occur
because of cost increases for lead that are less than 10 percent (in
constant dollars).
It appears that demand for lead will be more strongly influenced
by technologic developments and environmental restrictions that change
usage patterns. Examples include attrition of the tetraethyl lead
market for gasoline and the substitution of other bases ranging from
water to titanium and zinc for interior paints. Unquantified results
of studies show the demand for lead as largely insensitive to price.
The fact that there is little correlation between price increase and
rise in demand from year to year is consistent with the hypothesis
that demand for lead is price inelastic (Charles River Associates,
1971; American Metal Market, 1972).
Perhaps the most significant area of concern relates to the com-
petitive effects of controls for SC^. The competitive position of
secondary lead vis-a-vis the primary product has been noted, as well
as the increasing interchangeability of demand for lead from recycled
and virgin material. At the time of proposing NSPS for secondary lead
smelters, EPA (1973) noted the relatively higher costs of pollution
6-36
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controls required of the primary industry and reasoned that the NSPS
would not weaken the competitive position of secondary material in the
total lead market. This conclusion is not likely to be affected by
increased pollution control costs if they were on the order of no more
than 5 percent to secondary lead smelters.
Within the secondary lead industry, howeverj the competitive
effects are likely to be more significant. The trend to increasing
centralization of the secondary lead industry has been noted. Evi-
dence indicates that a larger share of the market is going to large
companies and some small companies are being forced out. It is prob-
lematic how much this existing trend might be accelerated by increases
on the order of 1 to 5 percent in production costs resulting from NSPS
for S02» It is true that this range more than covers the net income
margin of small companies. With a few companies dominating the mar-
ket, large producers might well absorb some or all of the additional
cost with the result that prices would be held down; lead would sell
at a price that did not fully cover increased expenses for many of the
approximately 20 small operators. Small firms would then be operating
at a deficit and in time would be forced out.
It is also true that new plants subject to NSPS controls for
S(>2 would be placed at a disadvantage vis-a-vis existing plants. To
analyze how the resulting cost differential would operate requires
more detailed data concerning control costs and the overall capital
and annual expenses of new and existing plants, production rates, the
6-37
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financial position of the parent companies and other factors that
affect position in the secondary lead market. These issues indicate
that in addition to a study of technological feasibility, a comprehen-
sive economic analysis is required in any consideration of possible
NSPS for this pollutant.
6-38
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7.0 CONCLUSIONS
7.1 Retention of Current NSPS
Any change in current NSPS for secondary lead smelters would be
unwarranted at this time. These standards are for particulates (0.022
gr/dscf) and for opacity «20 percent for blast and reverberatory
furnaces, <10 percent for pot furnaces). When the standards were set
in 1974, they were based on control technology available at the time.
There are no indications that the state of this technology has changed
since then. Best systems of control consisted of baghouses (fabric
filters) and venturi scrubbers, and today these still represent the
best technology for particulate removal. Efficiencies of collection
systems required to meet current NSPS for particulates are in line
with efficiencies reported elsewhere, with manufacturer estimates of
performance, and with the extremely limited test data available. The
standards are not too stringent, as evidenced by the fact that they
are being met and by the absence of reported difficulties in achieving
compliance.
In regard to more stringent standards, there is no substantial
evidence available by which they would be justified. The sample of
tests in which lower emission rates were achieved is entirely inade-
quate as a basis for any valid inferences about the general feasibil-
ity of meeting stricter standards. A literature search indicates no
more stringent levels in existence locally as a basis for comparison.
The very small (submicron) size particulates from reverberatory
7-1
-------
furnaces, against which the efficiency of high-energy venturi scrub-
bers and to a lesser degree of baghouses declines as compared with
larger particles, raises technical questions about how adequate
existing control systems would be in general to meet significantly
stricter standards.
Even if lower emission rates could be shown as entirely feasi-
ble, potential environmental gains would be marginal. Lowering the
allowable particulate emissions to half those now permitted would
capture about 1 additional ton/year from a 50-ton/day plant (Table
4-8). Total reductions from plants newly subject to NSPS in any one
year would not amount to 5 tons.
From the scarcity of available test data, it is concluded that
there is a strong need to assemble over the immediate future all
obtainable results as they become available. Analysis of an adequate
data base would be essential in determining whether technologic
improvements in control systems have occurred that are adequate to
support more stringent standards at a future time. Detailed data are
needed from tests by which to correlate performance of different con-
trol systems as a function of the type of material charged to the
furnace, particulate size distribution, inlet loading to the collec-
tor, parameters of the system (e.g., air-to-cloth ratios for fabric
filters, pressure drop and ratio of water to air flow for venturi
scrubbers), maintenance and other operating features of the smelter.
The relationship of percentage of opacity in the stack discharge from
7-2
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a control system to particulate grain loadings would be of interest.
Physical considerations, as well as the analogy of results in other
industries, suggest that a percentage of opacity lower than 20 or even
10 percent is associated with meeting particulate standards; but
quantititative data are lacking.
7.2 No Specific NSPS for Lead Emissions
It is concluded that no need exists for specific NSPS for lead
emissions from secondary smelters. The consensus of available evid-
ence strongly indicates that the current standards for particulates
promote installation of the best systems of control technology for
lead. The lead content of emissions vented by an adequately control-
led plant (i.e., one which meets or surpasses NSPS for particulates)
is no higher than 23 percent. The resulting content of lead in the
air at ground level, even at points of maximum downwind concentration,
would not approach the critical point of 2 fig/nr* on a 24-hour aver-
age basis. Specific NSPS for lead emissions would be essentially
redundant to current standards for particulates. Considerable proce-
dural involvement and expense to officials, both within the government
and outside, would be required with no commensurate environmental
gain.
It is also concluded that information regarding the rate and form
of lead emissions from secondary lead furnaces is somewhat incomplete,
in particular in regard to the disposition of lead-bearing particles
of different sizes. Tests under both laboratory and operating field
7-3
-------
conditions would be useful for comparing the distribution of lead-
bearing particles by size in baghouse catch and in the material vented
from the fabric filter control system. Most of the available material
indicates that particulate control systems trap at least as high a
percentage of lead particles as that present in the inlet loading; but
the data are fragmentary, represent diverse sources, and are inconsis-
tent with preliminary reports of a more recent test. Definitive
resolution of any question remaining requires a comprehensive material
balance on lead emissions from furnace to collector outlet.
A significant conclusion in regard to the effect of particulate
controls is that the rate of lead emissions may have been reduced
about 2 tons/year/plant. The cumulative reduction in total emissions
due to NSPS is estimated to be about 270 tons since 1974.
7.3 Study of Fugitive Emissions
It is concluded that inadequate information is available on the
extent of fugitive emissions of lead-bearing particles from secondary
lead smelters. It is not possible to assess how serious the impact of
such emissions may be in the vicinity of the plants or to determine
whether regulatory standards applying specifically to such emissions
are warranted. For example, it has been suggested that control of
fugitive emissions from lead smelters may be necessary to meet NAAQ8
for lead (EPA, 1978b). In addition to this question and the determi-
nation of typical emission rates from fugitive sources, investigation
is warranted into the relative contribution of process- and
7-4
-------
site-related sources to lead particulate matter in the atmosphere and
soil around secondary smelters, as discussed in Chapter 6*
It is also concluded that applicable technologies and procedures
for control of fugitive emissions should be investigated with the
specific objective of determining their efficiency quantitatively.
These include techniques such as flash agglomeration and improvements
and/or additions to hooding and venting to prevent escape of parti-
culate matter during smelting. Among procedures warranting investi-
gation are the effect of maintenance practices, dust storage in open
piles, and dust management around the smelter. It is concluded that
such investigations would provide information necessary not only to
determine whether fugitive emissions should be specifically regulated
and if so at what level, but also in deciding what form a standard
should take (e.g., in terms of maximum allowable emissions or of
prescribed standards of equipment and procedures).
7.4 Investigation of NSPS for SO? Emissions
It is concluded that NSPS to control S0£ emissions from sec-
ondary lead smelters appear technologically feasible at this time but
demonstration is lacking. The total output of S02 is not high from
the industry and more especially from plants that would become newly
subject to NSPS in any one year. However, the uncontrolled emission
rate in pounds per ton of lead product appears significant in compari-
son with that from controlled sources. The average or typical rate of
80 Ib/ton of metal charged from a reverberatory furnace is 20 times
7-5
-------
the permissible rate per ton of product from sulfuric acid plants (40
CFR 60). Although the average rate (53 Ib/ton of metal charged) is
lower for blast furnaces, the estimated range extends up to more than
150 Ib/ton. Control methods are now technologically feasible to
reduce SC>2 emissions by about 80 to 90 percent over the rate of
emissions from the furnace stack. However, it is not concluded that
NSPS for SC>2 are warranted for secondary lead smelters at this time.
An important consideration in regard to possible NSPS for SC>2
is potential cost to the secondary lead industry of additional con-
trols. Information on their cost and effects is inadequate to support
any conclusions. Best available evidence indicates that reduction of
S02 pollution and simultaneous control of particulates could be
achieved at capitalization costs in the probable range of 10 to 20
percent over the cost of a venturi scrubber system to control particu-
lates. This increment would not exceed 5 percent of the average price
of a ton of lead product and more likely is within 2 to 3 percent. It
also appears that this additional expense would have little effect on
the marketability of secondary lead. Demand for lead from both pri-
mary and secondary sources seems to be relatively inelastic.
It is concluded that some danger to small firms operating lead
smelters would result from the promulgation of NSPS for S(>2. It is
also deemed probable that new smelters required to undergo the expense
of providing S02 controls would face a competitive disadvantage
7-6
-------
relative to existing plants, the extent of which cannot be determined
from current information. In view of the limited manufacturer's data
obtainable and the generality of the estimates provided, further
investigation of costs is necessary. In particular, consideration
should be given to effects on* small companies and to the competitive
position of new plants vis-a-vis existing ones.
Because the uncontrolled rate of S(>2 emissions from secondary
lead smelters appears significant and because transfer of control
technology appears promising, it is concluded that the question of
NSPS for S02 warrants detailed investigation with emphasis on costs
and affordability.
7-7
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8.0 RECOMMENDATIONS
8.1 Current NSPS for Particulates and Opacity
For the present, NSPS should be retained at the current level of
0.022 gr/dscf for particulates and <20 percent for opacity «10
percent for pot furnaces).
Prior to the next review, comprehensive data should be gathered
from detailed tests and analyzed to determine performance of control
devices as a function of both system parameters and operating charac-
teristics of the smelter, as indicated in Section 7.1.
8.2 Comprehensive Data on Lead Content of Emissions
While no explicit NSPS regarding lead emissions from secondary
smelters are recommended at this time, it is recommended that compre-
hensive data be collected on the disposition of lead-bearing particles
emitted from furnaces. As discussed in Section 7.2, tests under
laboratory and field conditions are recommended with sufficiently
detailed results to construct materials balance of the lead emissions
by blast and reverberatory furnaces and to determine distribution of
lead particles by size in the inlet loading to and output from the
control system. It is recommended that tests be conducted to define
the emission rate of lead from control systems.
8.3 Fugitive Emissions
An investigation should be made of the extent to which fugitive
emissions represent a problem at secondary lead smelters controlled
under NSPS. Research and development should also be conducted into
8-1
-------
the most effective technologies and procedures for controlling such
emissions from both process- and site-related activities at secondary
lead smelters. These investigations should be directed toward
developing data by which to determine whether a specific NSPS to
cqntrol fugitive emissions at secondary level plants is warranted and
what form the regulation should take.
8.4 NSPS for SO? Emissions
It is recommended that action be taken to investigate the
question of NSPS for S02 emissions from secondary lead smelters.
Further recommendations relating to specific investigations are:
• costs, both capitalization and annualized (including operat-
ing and maintenance expenses), of such systems with particu-
lar reference to costs that might be incurred by relatively
small smelters (less than 50-tons/day capacity) if such new
plants are brought on-line or existing ones of this size are
modified or reconstructed.
• economic impacts of a regulatory standard for SC>2.
8-2
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9.0 REFERENCES
American Metal Market, 1972. Metal Statistics 1972: The Purchasing
Guide of the Metal Industries. 65th Edition. Fairchild
Publications, Inc. New York, N.Y.
American Air Filter Company, Inc., 1973. Manufacturers' brochures
supplied by private communications. Louisville, Kentucky.
Bechtel Corporation, 1978. Flue Gas Desulfurization Systems: Design
and Operating Parameters, SC<2 Removal Capabilities, Coal Prop-
erties and Reheat, Vols. I and II. Prepared for Office of
Research and Development, U.S. Environmental Protection Agency,
! EPA-600/7-78-030. Research Triangle Park, N.C.
I
Brobst, D.A. and W.P. Pratt, eds., 1973. U.S. Mineral Resources.
-' Geological Professional Paper 820. U.S. Government Printing
Office. Washington, D.C.
Chapman, J.D., and J.C. Sherman, eds., 1973. Oxford Regional
Economic Atlas—United States and Canada. The Cartographic
Department of the Clarendon Press. Oxford.
Charles River Associates, 1971. The Effects of Pollution Control on
Nonferrous Metals Industries: Lead. Cambridge, Mass. NTIS PB-
207-155.
Chemical Construction Corporation, 1970. Engineering Analysis of
Emissions Control Technology for Sulfuric Acid Manufacturing
Processes. Final Report. Public Health Service, National Air
Pollution Control Administration, Publication No. PB-190-393.
Vol. I.
Combustion Equipment Associates, 1978. Personal Communication with
Dr. F. Murad, July 10.
Cooper, H. B. Jr., and J. C. Sherman, eds., 1973. Oxford Regional
Economic Atlas—United States and Canada. Oxford University
Press. New York, N.Y.
Danielson, J. A. ed., 1973. Air Pollution Engineering Manual.
2nd Edition. U.S. Environmental Protection Agency. Office of
Air & Water Programs. Research^ Triangle Park, N.C.
Davis, W. E., 1973. Emission Study of Industrial Sources of Lead Air
Pollutants. Prepared by W. E. Davis and Associates for U.S.
Environmental Protection Agency. Research Triangle Park, N.C.
NTIS PB-223 652.
9-1
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Engineering-Science, Inc., 1971. Exhaust Gases for Combustion and
Industrial Processing. Washington, D.C. October 2.
Engineering-Science, Inc., 1977. Inspection Manual for Enforcement
of New Source Performance Standards, Secondary Lead Smelters.
Prepared for U.S. Environmental Protection Agency, Division of
Stationary Source Enforcement. EPA-340/1-77-001. Washington,
D.C.
Ferb, R. J. and N. J. Stevens, Research-Cottrell, Inc., 1978.
Scrubber Proves Out for Industrial Size Boiler. Power
Engineering.
Fine, P., H. W. Rasher, and S. Wakesberg, eds., 1973. Operation in
the Non-ferrous Scrap Metal Industry Today. National Associa-
tion of Secondary Material Industries, Inc. New York, N.Y.
Habegger, J., R. R. Cirillo, and N. F. Sather, 1976. Priorities and
Procedures for Development of Standards of Performance for New
Stationary Sources of Atmospheric Emissions. Prepared for the
Environmental Protection Agency by the Argonne National Labora-
tory. EPA-450/3-76-020. Research Triangle Park, N.C.
Hardison, L.C., et al., 1970. Study of Technical and Cost Informa-
tion for Gas Cleaning Equipment in the Lime and Secondary
Non-Ferrous Metallurgical Industries. Industrial Gas Cleaning
Institute. Rye, N.Y. NTIS, PB-198-137.
Hunt, W. F., C. Pinkerton, 0. McNulty, and J. Creason, 1971. A Study
in Trace Element Pollution of Air in 77 Midwestern Cities. In:
Trace Substances in Environmental Health. IV. D. P. Hemphill,
ed., University of Missouri Press, Columbia, Mo.
Kaplan, N. and M. A. Maxwell, 1978. Flue Gas Desulfurization of Com-
bustion Exhaust Gases. Presented at the Third National Confer-
ence, Interagency Energy/Environment R&D Program. June 1 fit 2.
Washington, D.C.
Kinkley, M.L., and R.B. Neveril, 1976. Capital and Operating Costs
of Selected Air Pollution Control Systems. Prepared for U. S.
Environmental Protection Agency. Office of Air and Waste
Management. Office of Air Quality Planning and Standards.
EPA-450/3-76-014. Research Triangle Park, N.C.
Levine, S. N., ed., 1978. The Dow Jones-Irwin Business Almanac.
Dow Jones-Irwin. Homewood, Illinois.
9-2
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9-3
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9-6
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
EPA-450/3-79-015
3. RECIPIENT'S ACCESSION NO.
4. TITLE AND SUBTITLE
S. REPORT DATE
A Review of Standards of Performance for New
Stationary Sources - Secondary Lead Smelters
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
John W. Watson and Kathryn J. Brooks
8 PERFORMING ORGANIZATION REPORT NO.
MTR-7871
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Metrek Division of the MITRE Corporation
1820 Dolley Madison Boulevard
Me Lean, VA 22102
10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.
68-02-2526
12. SPONSORING AGENCY NAME AND ADDRESS
13. TYPE OF REPORT AND PERIOD COVERED
DAA for Air Quality Planning and Standards
Office of Air, Noise, and Radiation
U. S. Environmental Protection Agency
Research Triangle Park, NC 27711
14. SPONSORING AGENCY CODE
EPA 200/04
15. SUPPLEMENTARY NOTES
16. ABSTRACT
This report reviews the current Standards of Performance for New Stationary
Sources: Subpart L - Secondary Lead Smelters. It includes a summary of the
current standards, the status of applicable control technology, and the ability
of secondary lead smelters to meet the current standards. Compliance test
results are analyzed and a recommendation made to retain the current standard.
Information used in this report is based upon data available as of November
1978.
17.
KEY WORDS AND DOCUMENT ANALYSIS
a.
DESCRIPTORS
b.IDENTIFIERS/OPEN ENDED TERMS
c. cos AT I Field/Group
18. DISTRIBUTION STATEMENT
Release Unlimited
19. SECURITY CLASS (This Report)
Unclassifffed
21. NO. OF PAGES
123
20. SECURITY CLASS (Thispage)
Unclassified
22. PRICE
EPA Form 2220-1 (Rev. 4-77) PREVIOUS EDITION is OBSOLETE
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