United States
Environmental Protection
Agency
EPA/540/M5-91/005
Aug.1991
SUPERFUND INNOVATIVE
TECHNOLOGY EVALUATION
Demonstration Bulletin
Flame Reactor
Horsehead Resource Development Company, Inc.
Technology Description: The Horsehead Resource Develop-
ment Company, Inc. (HRD) Flame Reactor is a patented and
proven high temperature thermal process designed to safely treat
industrial residues and wastes containing metals. During pro-
cessing, the waste material is introduced into the hottest portion
of the Flame Reactor, where the wastes are subjected to a very
hot reducing gas (greater than 2000°C) produced from the com-
bustion of solid or gaseous hydrocarbon fuels in oxygen-enriched
air. At these high temperatures volatile metals in the waste are
volatilized and organic compounds are destroyed. The waste
materials react rapidly, producing a non-leachable slag and gases,
including steam and volatile metal vapors. The metal vapors
further react and cool in the combustion chamber and cooling
system to produce a metal-enriched oxide that is collected in a
baghouse. The resulting metal oxides can be recycled to recover
the metals. The amount of waste reduction to slag and oxide
depends on the chemical and physical properties of the waste
material.
Nonvolatile metals are vitrified in the slag that leaves the reactor
from the slag separator. After testing to ascertain that the slag is
nonhazardous, it can generally be recycled as clean fill material.
If the slag cannot be recycled because it is determined to be toxic
after Toxicity Characteristic Leaching Procedure (TCLP) testing, it
can be disposed of in a permitted landfill. Figure 1 presents a
schematic diagram of the HRD Flame Reactor.
Waste Applicability: The Flame Reactor technology can po-
tentially be applied to many types of granular solids, soil, flue
dust, slag, and sludge containing very high concentrations of
heavy metals. Wastes to be treated by the Flame Reactor
should be dry (less than 15% total moisture) and fine-grained
(less than 200 mesh) to react rapidly. Larger particles (up to 20
mesh) can be processed, but may decrease the efficiency of
metals recovery or the capacity of the reactor. Wastes not
meeting the moisture content and particle size criteria require
pretreatment. Generally, wastes with high concentrations of
heavy metals that have a significant market value (zinc, lead,
arsenic, and possibly silver and gold) should enhance the overall
process economics. Product metal oxide containing valuable
metals can be further processed for metal recovery in industrial
smelters.
Demonstration Results: The HRD Flame Reactor was demon-
strated at the HRD facility in Monaca, Pennsylvania, in March
1991. Approximately 72 tons of waste material from the National
Smelting and Refining site in Atlanta, Georgia, was treated during
all phases of testing for the HRD SITE demonstration. This
waste material is a granular secondary lead smelter blast furnace
soda slag containing approximately 15.0% carbon, 10.3% iron,
12.2% sodium, 5.3% sulfur, 5.4% lead, 5% silicon, 2.5% chlorine,
0.4% zinc, 0.5% arsenic, 0.04% cadmium, many other metals
and inorganic chemicals, and approximately 15% water. The
NATURAL CAS
couausnoH AIR
COUFRES90H
COUBU3T1OM
CIIAUBER
SLAG
SEPARATOR
1 s.
POOT-COUBUOT1OH AIR
Figure 1. HRD Flame Reactor Process Flow Schematic
Printed on Recycled Paper
-------
waste material was dried and passed through a hammermill prior
to treatment in the Flame Reactor. The demonstration test runs
included a series of shakedown runs to establish optimal operat-
ing conditions, a blank run during which no waste was treated,
three test runs, and a series of additional runs to evaluate system
durability and to process remaining waste material.
Extensive process operating data and analytical samples were
collected. The operating data included raw waste feed and
processed waste accumulation rates, natural gas and oxygen
consumption rates, electrical consumption, temperatures through-
out the system, and flow rates throughout the system. Laboratory
analyses included analyses of the raw feed for metals, energy
content, ash content, moisture, sulfur, chloride, fluoride, carbon,
and total organic carbon content. Effluent samples (processed
waste slag and baghouse dust) were analyzed for metals. The
raw feed and processed waste slag were also analyzed by TCLP
testing for metals. Concentrations of CO, CO2, O2, NOx, SO2, total
hydrocarbons, and metals in the stack gases were also mea-
sured. Analytical data are summarized in Tables 1 and 2.
Key findings from the HRD SITE demonstration are summarized
betow:
« Although samples of the raw feed failed the TCLP test due
to high cadmium and lead levels, all samples of processed
waste slag passed the TCLP test for all metals. The pro-
cessed waste slag can be disposed of in a sanitary landfill or
used as fill material.
• Lead and zinc from the raw feed (5.4% and 0.4% weight)
were removed from the processed waste slag (0.6 and 0.1%
weight) and concentrated in the baghouse dust (18.0% and
13.2% weight). The baghouse dust may be recycled for its
lead content. The process showed better than 90% recov-
ery for both lead and zinc.
• The weight of the waste was reduced by approximately
30%, largely due to removal of water and carbon during
pretreatment and treatment.
• With the exception of SO2, stack gas emissions were within
HRD permit limits. SO,, emissions were high due to the
amount of sulfur in the waste. The SO2 emissions could
readily be controlled with the use of a scrubber.
An Applications Analysis Report and a Technology Evaluation
Report describing the complete HRD SITE demonstration will be
available in the Spring of 1992.
Table 1. Metal Concentration Ranges in Influent and Effluent Wastes
(Preliminary)
Arsenic
Cadmium
Copper
Iron
Lead
Zinc
Raw Feed
(mg/kg)
428-582
380-512
1,460-2,590
95,600-111,000
48,200-61,700
3,210-4,660
Processed Slag
(mg/kg)
92.1-675
2.3-13.5
2,730-3,890
167,000-228,000
1,560-11,400
709-1,680
Baghouse Dust
(mg/kg)
1,010-1,130
1,080-1,370
1,380-1,670
29,100-31,800
159,000-180,000
10,000-16,200
Table 2. TCLP Results (Preliminary)
Arsenic
Barium
Cadmium
Chromium
Lead
Mercury
Selenium
Silver
Raw Feed
(mg/L)
<0.210-0.264
0.0177-0.0675
7,61-15.8
0.140-0.283
4.35-6.80
<0.010
<0.030-0.160
<0.050
Processed Slag
(mg/L)
<0.2 10-0.930
0.109-0.281
<0.050
<0.060
<0.330
<0.010
<0.030-0.0730
<0.050
For Further Information
EPA Project Managers
Donald A. Oberacker
U.S. EPA
Office of Research and Development
Risk Reduction Engineering Laboratory
26 West Martin Luther King Drive
Cincinnati, OH 45268
(513) 569-7510 (FTS: 684-7510)
Marta K. Richards
U.S. EPA
Office of Research and Development
Risk Reduction Engineering Laboratory
26 West Martin Luther King Drive
Cincinnati, OH 45268
(513) 569-7783 (FTS: 684-7783)
United States
Environmental Protection
Agency
Center for Environmental
Research Information
Cincinnati, OH 45268
BULK RATE
POSTAGE & FEES PAID
EPA
PERMIT No. G-35
Official Business
Penalty for Private Use $300
EPA/540/M5-91/005
------- |