?/EPA
United States
[Environmental Protection
Agency
EPA/540/SR-95/504
May 1995
SUPERFUND INNOVATIVE
TECHNOLOGY EVALUATION
Emerging Technology
Summary
Reclamation of Lead from
Superfund Waste Material Using
Secondary Lead Smelters
Stephen W. Paff and Brian E. Bosilovich
Hundreds of sites across the United
States are contaminated with lead from
various sources. Through a Coopera-
tive Agreement with the U.S. Environ-
mental Protection Agency's (EPA) Risk
Reduction Engineering Laboratory, the
Center for Hazardous Materials Re-
search (CHMR), in conjunction with a
major secondary lead smelter, has dem-
onstrated that secondary lead smelters
may be used economically to reclaim
lead from a wide range of lead-contain-
ing materials frequently found at Su-
perfund sites. Such materials include
battery case materials, lead dross, and
other debris containing greater than 1%
lead.
During the study, CHMR and the
smelter reclaimed lead from five sets
of materials, including two Superfund
sites containing primarily battery cases
and one battery breaker/smelter site
with a variety of lead-containing mate-
rials. Between 4 and 1500 tons of ma-
terials from each of these sites were
excavated or collected and processed
at the smelter, while the research team
assessed the effects on furnace opera-
tion and performance. Two additional
sets of materials, one from the demoli-
tion of a house containing lead-based
paint and the other from work on a
bridge coated with lead paint, were also
processed in the smelter. The results
showed that it was technically feasible
to use the secondary lead smelter to
reclaim lead from all of the materials.
CHMR also assessed the economics
of using secondary lead smelters to
reclaim lead from Superfund sites and
developed a method for estimating the
cost of reclaiming lead. This method
develops cost as a function of material
excavation, transportation, and pro-
cessing costs combined with cost ben-
efits received by the smelter (in the
form of recovered lead, reduced fuel
usage, and/or reduced iron usage). The
total remediation costs using second-
ary lead smelters for the sites and ma-
terials studied varied between $35 and
S374/ton, based on a conservative mar-
ket price for lead. The costs were pri-
marily a function of lead concentration,
the market price for lead, distance from
the smelter, and the amount of materi-
als that became incorporated into slag
from the process, although other fac-
tors affected the economics as well.
Materials with high concentrations of
lead were significantly less expensive
to remediate than those with low con-
centrations. The cost to remediate ma-
terials that left few slag residues in the
Printed on Recycled Paper
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furnace was significantly lower than the
cost to remediate materials that con-
tained significant slagging components.
This Project Summary was developed
by EPA's Risk Reduction Engineering
Laboratory, Cincinnati, OH, to announce
key findings of this SITE Emerging
Technology Project that are fully docu-
mented in a separate report of the same
title (see Project Report ordering infor-
mation at back).
Introduction
Lead is used in the production of vari-
ous consumer and commercial items, from
automobile and equipment batteries to
paints to crystal. This widespread use has
made it one of the most frequent contami-
nants at sites on the National Priorities
List (NPL). The most common current
treatment of lead contaminated wastes at
Superfund sites is immobilization, either
onsite or in a landfill. Remedial approaches
involving recovery of lead are often pre-
ferred over immobilization, which wastes
usable lead. One such remedial approach
is the use of secondary lead smelters for
recovery.
The objective of this project was to de-
termine the technical and economical fea-
sibility of processing select lead-containing
wastes at secondary smelters. Five types
of waste materials were processed a single
secondary smelter in different tests. The
materials tested include material from three
Superfund sites (the Tonolli site in
Nesquehoning, PA; the Hebelka site in
Weisenburg County, PA; and the NL In-
dustries site in Pedricktown, NJ) and two
other sources (demolition material and
abrasive bridge blasting material). The re-
port summarized here presents the activi-
ties conducted, the experiments performed,
and the results obtained.
Process Description
The overall process for the project in-
volves acquiring the waste material, trans-
porting it to a secondary smelter, blending
it with typical feeds, and smelting it to
reclaim usable lead. A schematic of this
process is shown in Figure 1, and the
individual steps are described in more de-
tail below.
Material Acquisition,
Preprocessing, and
Transportation
The first step in reclaiming lead from
Superfund wastes is acquiring and trans-
porting the material to one smelter. Gen-
erally, this involves excavation or
collection, pre-processing, and transport
to the smelter. The lead-containing waste
Transport of material
'CO
Rocks, soils, debris
Mixing
Slag to
disposal
Smelter
Typical
smelter feed
Figure 1. Schematic of reclamation process.
material is typically excavated from lead-
acid battery Superfund sites. Materials may
be collected from other sources, such as
bridge blasting or demolition operations.
Some materials often require some type
of processing before entering the furnace.
Preprocessing includes screening to re-
move soil, large stones, or non-contami-
nated debris. Soil cannot be processed
through a secondary smelter. Larger de-
bris (>12 in.) is also removed because
large material tends to remain unburnt in
reverberatory furnaces. This causes slug-
gish performance and slows productivity
by the reverberatory furnaces. Preprocess-
ing can be done at the site or at the
smelter, depending on which is more cost
efficient.
Blending with Typical Furnace
Feeds
Once the material arrives at the sec-
ondary lead smelter, it is blended with
typical feed before processing through the
smelter's reverberatory and blast furnaces.
This mixing prevents problems associated
with the layering of the test material in the
furnaces. Typical blend ratios range from
10% to 50% by weight, and are deter-
mined based on treatability tests and other
factors, such as lead, sulfur, iron, or ash
content.
Smelting Process
As part of normal secondary lead smelt-
ing operations, spent batteries received at
the smelter are crushed to release the
sulfuric acid and then processed through
a sink/float system to separate the battery
cases. Dual reverberatory furnaces at the
smelter are charged with material from
the sink/float system as well as other lead-
containing material. These furnaces are
fueled with natural gas and oxygen. Re-
verberatory furnaces are tapped for slag,
which typically contains 60% to 70% lead,
and a soft (pure) lead product.
Dual blast furnaces are charged with
the slag generated from the reverberatory
furnaces as well as other lead-containing
materials. These furnaces are fueled by
coke and oxygen-enriched air. Iron and
limestone are added as fluxing agents to
enhance furnace production. The blast fur-
naces are tapped continuously to remove
lead and intermittently to remove the slag.
The blast slag, which contains primarily
silica and iron oxides, is transported to an
offsite landfill for disposal.
Lead produced in the blast and rever-
beratory furnaces is transferred to the re-
fining process where additional metals are
added to make specific lead alloys. The
lead is then pumped to the casting opera-
tions where it is molded into ingots for use
in the manufacture of new lead-acid bat-
teries.
Test Materials
Materials from three Superfund sites as
well as two additional sets of lead-con-
taining materials were processed during
this project. Table 1 presents a summary
of the materials tested and the evalua-
tions. A short description of each of the
five evaluations follows the table. The feed
rates are presented as weight ratios of
test material to total furnace feed.
Tonolli Superfund Site
The Tonolli site was a battery breaking
and smelting facility located in
Nesquehoning, PA. Piles of ebonite rub-
ber and polypropylene battery case pieces
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Table 1. Summary of Demonstration Sites
Test Parameter
Tonolli Site
Demolition Waste
NL Industries site
Pen n DOT
Site Type
Integrated battery
breaker, smelter,
and lead refiner
Automobile junk
and salvage yard
Not applicable
Integrated battery
breaker, smelter,
and refiner with
onsite landfill
Bridge blasting
operation to
remove lead paint
site landfill
Length of Test
Material Type
5 days
Rubber and plastic
battery cases
1 day
Rubber and plastic
battery cases with
some soil
2 days
Demolition debris
coated with lead
paint
Preliminary: 4 days
Full: 3 months
Lead slag, debris,
dross, ingots; bat-
tery case pieces,
baghouse bags,
pallets, cans
1 day
Iron shot bridge
blasting material
Amount
Processed
Percent Test
Material in Feed
84 tons
10%
8 tons
17%
4 tons
5%
Preliminary test:
370 tons
Full-scale test:
1200 tons
20% to 50%
6 tons
13%
Lead Concentration
Preprocessing
Difficulties
Encountered
3.5%
None
Attempted to
process in reverb,
but material was
too large
14.7%
Reduced to less
than 1/4 in. in a
hammermill
None
1%
Reduced in size
with a pallet
shredder
Initial feed ratio
was too high
Preliminary: 57%
Full: 30% to 50%
Large pieces re-
moved for process-
ing in the blast
furnace
Reverb could not
process 100%
waste material
3.2%
None
Material was too
moist to process in
reverb furnace
were tested, without any preprocessing.
The material had an average lead con-
centration of 3.5%. Approximately 84 tons
of material were fed at a ratio of 10%
through a reverberatory and blast furnace.
The material was too large to be readily
processed in the reverberatory furnace but
was successfully processed in the blast
furnace.
Hebelka Superfund Site
The Hebelka site was a former automo-
bile junk and salvage yard located in
Weisenburg Township, PA. The site con-
tained battery case debris mixed with some
soil that had an average lead concentra-
tion of 14.7%. Approximately 20 yd3 of
material were transported to the smelter.
This material was first reduced in size to
less than 1/4-in. with a hammermill. The
material was successfully fed to one of
the dual reverberatory furnaces at a feed
ratio of 17%.
Demolition Waste
The demolition waste consisted mainly
of wood coated with lead based paint and
had a lead concentration of between 0.5%
and 1% The test material was shredded
in a pallet shredder before it was smelted.
The demolition debris was processed
through both reverberatory furnaces at
feed ratio of 10% test material, by weight.
At this weight ratio the test material com-
prised 50% of the volume fed to the fur-
naces. This high volumetric ratio caused
malfunctions in the furnaces, so the feed
ratio was reduced to 5%, at which point
the material was successfully fed.
NL Industries Superfund Site
The NL Industries site in Pedricktown,
NJ, was an integrated battery breaking,
smelting, and refining facility with its own
onsite landfill. There was a wide variety of
materials at the site including lead slag,
dross, debris, ingots, hard heads (large
chunks of metallic lead), battery case de-
bris, baghouse bags, and contaminated
pallets and iron cans. The evaluation was
conducted in two parts: a preliminary in-
vestigation and a full-scale investigation.
During the preliminary investigation, ap-
proximately 370 tons of all types of the
above materials were processed. Analy-
ses revealed an average lead concentra-
tion of 57%; however, the materials ranged
in concentration from 7% to 69% lead.
The larger pieces of debris were removed
and processed through a blast furnace;
while the bulk of the material was fed into
a reverberatory furnace at feed ratios of
up to 100%. The feed was sufficiently
dense to cause breakdowns in the rever-
beratory furnace conveyor feed system,
so the feed ratio was reduced to 50% test
material, by weight.
During the full scale operation, approxi-
mately 1200 tons of material were trans-
ported to the smelter over a three month
period. During the first two months the
test material, which contained approxi-
mately 45% by weight lead, was processed
in the reverberatory furnace, at a feed
ratio of 20% to 30%. The ratio was limited
because of high amounts of calcium in
the material. The high calcium concentra-
tion slowed the operation of the furnaces.
During the last month of the evaluation,
the test material consisted mainly of larger
pieces of slag and debris with an average
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lead concentration of 30%. This material
was charged to one of the blast furnaces
at a feed ratio of approximately 30%.
Pennsylvania Department of
Transportation
The Pennsylvania Department of Trans-
portation (PennDOT) used an iron-shot
abrasive blasting material to remove lead-
based paint from a bridge in Belle Vernon,
PA. Sixteen 55-gal steel drums of this
material, containing an average of 3.2%
lead, were processed at the smelter. The
material contained too much moisture to
be incorporated into the reverberatory feed.
The test material, including the drum, was
charged directly to a blast furnace at a
feed ratio of approximately 13%, by weight.
The bridge blasting material was primarily
iron (60%) with 5% calcium and 5% to
10% misture content.
Test Procedures
Test material was charged to either the
reverberatory furnaces or blast furnaces,
depending primarily on the size of the
material, but also on other factors such as
lead content and percent ash. Project per-
sonnel collected samples and data to as-
sess the furnace performance, characterize
the input material, and characterize the
furnace outputs. Table 2 shows the pa-
rameters that were measured and how
they were obtained. The input material
parameters were characterized to provide
information related to the feed, so that
comparisons of the effects of different
feeds could be made. The furnace perfor-
mance parameters, such as oxygen us-
age, fuel usage, furnace feed rates, etc.,
provided important furnace operation in-
formation while the experiments were con-
ducted, principally indicating when
production levels were falling or materials
were clogging in the furnace. The output
parameters were the most important mea-
surements of furnace performance, includ-
ing production rates and quality, as well
as residuals generation.
The data generated from measurements
and sample analyses were used to com-
pare the performances of the test and
control furnaces. The amount of lead in
each product is useful in making a mass
balance for the lead. Other parameters,
such as oxygen, air, and fuel, are useful
in determining the cost for processing the
test material.
Results
In general, the study demonstrated that
various materials may be processed in
secondary lead smelters with relatively few
effects on overall furnace performance.
Table 2. Input, Output, and Operating Parameters
Input Material
Characterization
Furnace Performance
Parameters
Furnace Output
Parameters
total lead (S)
sulfur (S)
silica (S)
calcium (S)
moisture content (S)
density (M)
particle size distribution (M)
BTU value (S)
test material in the feed (M)
air flow (M)
% oxygen enrichment (M)
fuel usage (M)
lead inputs (S)
iron inputs (S)
% test material in feed (M)
lead production rates (M)
slag production rates (M)
slag viscosity (Of
% lead in the slag (S)
% sulfur in the slag (S)
back pressure (M)
sulfur dioxide emissions (M)
calcium sulfate sludge (S)
*(S)=Sample (M)=Measurement (O)=Operator Observation
The most significant effects were caused
by processing materials in a furnace with-
out properly preprocessing it or by pro-
cessing too much material at one time.
For example, the Tonolli feed was too
large to be processed effectively in the
dual reverberatory furnaces. This caused
the furnace production to slow down sig-
nificantly. Later, the same type of material
from the Hebelka site was successfully
processed in the reverberatory furnaces
after it had been shredded in a hammermill
to a particle size of less than 1/4-in. The
NL Industries site material was initially
unsuccessfully processed at a 100% feed
ratio because it was too dense for the
feed system. When the ratio of test mate-
rial to total feed was lowered to 50% the
material was processed with few prob-
lems.
Feed Ratios
The normal feed-to-waste ratio for these
materials was one of the parameters tested
during this study. Based on furnace per-
formance and operations results, it was
possible to determine whether the furnace
performed successfully or unsuccessfully
at any given feed ratio. A test is consid-
ered to be unsuccessful if the feed ratio of
test material has to be lowered, or discon-
tinued altogether.
Test results show that the successful
mix ratios are strongly a function of the
percentage of lead in the waste material.
Figure 2 shows the successful feed ratios,
plotted against the percentage of lead in
the waste material (i.e., before blending
with normal feed). The results are nearly
linear from streams containing 3% lead to
those containing 60% lead. This delin-
eates the region marked "successful" on
the figure. When the feed ratios versus
lead concentration for unsuccessful runs
are plotted, a second region (the "unsuc-
cessful" area) emerges. Finally, a third
region, in which no tests were performed,
is also marked on the figure. No test feed
with more than 60% lead was fed to the
furnaces, so the regions in the range above
60% lead cannot be determined from the
experimental results.
Reclamation Efficiency
In determining whether the process is
suitable for reclamation of lead, it is im-
portant to determine whether the smelter
actually reclaimed the lead in the test ma-
terial. Unfortunately, there is no way to
accurately measure the extent of recla-
mation because the test material has to
be mixed with typical feed. Based on con-
servative assumptions and furnace output
parameters such as initial lead content
and percent ash, CHMR developed a
method to estimate the minimum recla-
mation efficiency. This method indicated
that lead was reclaimed from all test ma-
terials over a range of efficiencies, from
an estimated 70% for the abrasive blast-
ing material to 99.5% for NL Industries
material.
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100%
o"
80%
"§ 60%
.c
I 40%
I
w
^ 20%
0%
X-*
\Unsuccessful
x*
*'
0%
10%
50%
20% 30% 40%
% Lead in test material
Successful experiment A Unsuccessful experiment
60%
Figure 2. Percent lead in test material versus feed ratio.
Economics
CHMR used the experimental data and
other information to develop an economic
model based on the following costs and
values of recovered materials:
• Excavation costs
• Transportation costs
• Smelter processing base cost
• Additional production costs associated
with storage and handling of an
atypical material at the smelter
• Additional disposal costs
• Lead recovery
• Reduction of iron, coke, or other
furnace feeds.
With this model, the costs in the follow-
ing table have been estimated for the ma-
terials used in this evaluation. Table 3
includes two costs, the first is based on a
conservative market value for lead ($6507
ton) and the second on a more plausible
long-term value for lead ($750/ton). Note
the relationship between the costs and
some of the material characteristics. Lower
lead content causes an increase in costs,
whereas ash content and distance from
the smelter have a lesser effect.
Conclusions
The conclusions drawn from the study
are:
• Lead was successfully reclaimed from
a variety of materials found at many
Superfund sites, including battery case
pieces, slag, dross, lead debris, spent
abrasive material, and demolition
material contaminated with lead paint.
The lead concentration in these
materials ranged from 1 % to 45%
• The economics of reclaiming lead
depend on lead concentration, market
price for lead, distance from the
smelter, percent of test material that
becomes incorporated into the final
slag, iron content, BTU value of the
test material, and sulfur content.
• The cost for recovering lead from the
five sites selected for this project,
based on a conservative market price
for lead ($650/ton), ranged between
$80 and $374/ton.
Overall, CHMR concludes that second-
ary lead smelters provide a viable alterna-
tive to stabilization and disposal for the
treatment of wastes found at battery
breaker and some Superfund sites. This
process also makes it possible to recycle
and reuse lead which is a useful resource.
Table 3. Estimated Cost of Remediating Sites
Site
P=$650/ton
P=$750/ton
Distance(miles)
%Ash
% Lead
Tonolli
Hebelka
Demolition Material
NL Industries
PennDOT
$228
174
374
80
231
$224
160
373
35
228
40
75
100
300
250
20
30
4
65
70
3.5
14.7
1.0
45.0
3.2
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Stephen W. Paff and Brian E. Bosilovich are with the Center for Hazardous
Materials Research.
Laurel Staley is the EPA Project Officer (see below).
The complete report, entitled "Emerging Technology Report: Reclamation of Lead
from Superfund Waste Material Using Secondary Lead Smelters," (Order No.
PB95-199022; Cost: $19.50, subject to change) will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Risk Reduction Engineering Laboratory
U.S. Environmental Protection Agency
Cincinnati, OH 45268
United States
Environmental Protection Agency
Center for Environmental Research Information
Cincinnati, OH 45268
Official Business
Penalty for Private Use
$300
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EPA/540/SR-95/504
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