-------
per second (g/sec), compared to a Tier II screening level
of 0.091 g/sec. The addition of a wet scrubber would
probably reduce the HC1 emission to below the Tier II
screening limit.
3. The HRD Flame Reactor achieved a net weight
reduction when the waste feed was processed into
oxide product and effluent slag.
The secondary lead smelter slag used in the SITE
demonstration achieved a net weight reduction of 36.6
percent. About 23.1 percent of this weight reduction
resulted from the conversion of carbon to CO2, moisture
to steam, chloride to HC1 gas, and sulfur to SO2. The
remaining 13.5 percent weight reduction is partially
attributed to the liberation of oxygen from metal
compounds in the waste feed, when the metal
compounds were reduced by CO to metal vapor and
C02.
4. HRD case studies suggest that metals are recovered
most efficiently when the waste feed is pretreated to
a PSD where 80 percent by weight is less than 200
mesh (0.0029 inch) maximum particle size.
The PSD of the waste feed and the brief residence time
in the reactor (between 0.1 and 0.5 seconds) affect the
kinetics of the treatment reactions. Because the
residence time in the reactor is very short, a small
particle size is required for efficient heat and mass
transfer. As the percentage of smaller particles in the
waste feed increases, so does the potential reactive
surface area. The greater the surface area, the more
likely that volatile metals will be vaporized during
treatment, thereby increasing the percent recovery of
recyclable volatile metals. For the demonstration, 66.6
percent of the waste feed particles were smaller than
200 mesh (0.0029 inch or 75 microns). This PSD
yielded a 77.7 percent recovery of lead. Higher percent
recoveries would be expected if the PSD showed a
higher percentage of particles smaller than 200 mesh.
Case Study D-2 (Appendix D of this report) presents
data comparing the percent recovery of lead and zinc
from lead blast-furnace slag with two different PSDs.
The milled slag (PSD 70 percent smaller than 200
mesh) exhibited 85 and 95 percent recovery for zinc and
lead, respectively; the screened slag (no PSD given, but
assumed coarser than the milled slag) showed 49 and 80
percent recovery for zinc and lead, respectively. For
optimal reaction conditions, HRD recommends that 80
percent of the waste feed be less than 200 mesh. This
can be accomplished by using a hammermill.
5. The demonstration collected data only on toxic
metals; however, data from another study indicate
that the HRD Flame Reactor is greater than 99.99
percent effective in destroying and removing certain
organic compounds.
HRD has performed tests using CC14 (see Appendix D,
Case Study D-6, of this report). The HRD Flame
Reactor achieved destruction and removal efficiencies
of 99.9986 percent when the initial concentration of
CC14 was 5 percent. Although further testing is
necessary to confirm the reproducibility of these
results, the high temperatures (greater than 2,000°C) at
which the technology operates should be sufficient to
destroy or remove most organic contaminants. Further
studies of destruction of organic contaminants need to
be performed
6. During the demonstration, the HRD Flame Reactor
had no major operational problems; however,
auxiliary systems such as the oxide product
collection system, cooling water system, and feed
system experienced problems that did not affect the
operation of the Flame Reactor.
The oxide product collection system, consisting of a
shell-and-tube heat exchanger, a baghouse, an induced
draft fan, and a stack, was undersized for the
; demonstration. The Flame Reactor was sized to handle
20,000 tons per year (tpy) of EAF dust, but the oxide
product collection system was put together from surplus
zinc smelter parts and cannot handle the volume of gas
that would be generated from processing 20,000 tpy of
EAF dust. During the demonstration, the waste feed
(SLS slag) was processed at 0.9 tons per hour (7,800
tpy). The Flame Reactor system was typically shut
down after about 4 hours of operation, because the
oxide product collection system was undersized. For a
commercial operation, the oxide product collection
system would include a larger baghouse and a higher
capacity induced draft fan. Because of this addition, the
existing heat exchanger would not be required.
The cooling water system also developed problems. The
supply line to the shell-and-tube heat exchanger
developed an underground leak. Makeup water was
added to the cooling tower. This problem did not affect
the operation of the reactor and would not occur during
commercial operation because the heat exchanger
would not be used.
During Run 2, one of the day-bin screw feeders in the
feed system jammed. For approximately 30 minutes, the
other day bin was utilized at twice the normal capacity
to keep the waste feed rate constant. The operation was
not adversely affected.
7. The HRD thermodynamic model can be used to set
preliminary operating conditions to determine
order of magnitude estimates for parameters used
in a cost estimate, such as fuel and oxygen flow rates.
The thermodynamic model that HRD used to establish
the values of the two reactor control parameters
(particle residence time and reducing conditions), to
calculate the operating parameters (waste feed rate,
fuel flow rate, and oxygen flow rate), and to predict
oxide product and effluent slag formation tares did not
work well for the SLS slag waste feed. This model was
developed from data for EAF dust which is different in
13
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chemical composition from the SLS slag waste feed.
The parameters determined from the model were
adjusted during the shakedown runs. It is recommended!
that the model only be used to set preliminary
operating conditions and to determine order of
magnitude estimates for parameters used in a cost:
estimate, such as fuel and oxygen flow rates.
8. The HRD Flame Reactor system processed SLS slag
from the NSR site at a cost of $932 per ton. Other!
data from case studies show that the HRD Flame
Reactor can process other types of waste for $208
per ton.
The estimated cost per ton for treating SLS ranges from;
$208 for a 50,000 tpy waste treatment scenario that
includes a more efficient waste pretreatment system!
than presently exists at the HRD facility to a high price
of $932 for the SITE Demonstration scenario. The
estimated cost of the HRD Flame Reactor system are;
highly site-specific and rather difficult to identify
without accurate data from a site remedial investigation
report or waste profile. Variability in the waste
characteristics and of the costs of transporting waste to
the HRD Flame Reactor and transporting, shipping,
and handling residuals, could significantly affect costs:
presented in this economic analysis. Costs presented ini
the economic analysis are order-of-magnitude \
estimates and are rounded to the nearest dollar. A more \
detailed discussion of the economics of this technology,
is presented in Section 4. In addition, Appendix D, Case
Studies, contains additional economic data.
3.5 Environmental Regulations
Pertinent to the HRD Flame Reactor
This section discusses regulatory requirements pertinent to
treating hazardous waste with the HRD Flame Reactor.i
Currently, all wastes treated by the HRD Flame Reactor are ;
transported from remediation sites to the reactor's location
in Pennsylvania. Such waste treatment is considered off-site i
treatment, and all substantive and administrative regulatory
requirements for waste transport, storage, treatment, and
disposal at the federal, state, and local level must be ;
fulfilled. If a mobile or transportable HRD Flame Reactor is
developed for on-site treatment at Superfund sites, the |
substantive requirements discussed in this section would be
considered as applicable or relevant and appropriate !
requirements (ARAR); however, the administrative !
requirements (permits) would not have to be fulfilled.
This section discusses the permits required for the SITE j
demonstration project as well as regulatory requirements
that would apply if the HRD operated as a fully
commercialized treatment system.
Potential HRD technology users should be aware of, and
make sure that they satisfy the requirements of, all
applicable local, state, and federal regulations, such as
RCRA revisions, the revised Clean Air Act, and state
hazardous waste regulations.
3.5.1 Permits Required for the SITE
Demonstration
HRD was required to obtain an EPA RD&D permit to
operate the Flame Reactor for the SITE demonstration. This
permit, issued in December 1990, authorizes hazardous
waste research, development, and demonstration activities
and satisfies the requirements of RCRA Subtitle C. The
permit required HRD to prepare the following documents: 1)
waste analysis plan [40 CFR 264.13]; 2) inspection
schedules and logs [40 CFR 264.15]; 3) personnel training
plan [40 CFR 264.16(d)]; 4) contingency plan [40 CFR
264.53(a)]; 5) operating record [40 CFR 264.73]; 6) closure
plan [40 CFR 264.112(a)]; and 7) cost estimate for facility
closure [40 CFR 264.142(d)]. These documents were
completed by HRD and are maintained at the HRD Flame
Reactor facility in Monaco, Pennsylvania.
The RD&D permit allows HRD to store hazardous wastes
in containers, indoor silos, and indoor waste piles. The
permit also allows HRD to treat the following RCRA-coded
wastes for research purposes: D004 (arsenic), D005
(barium), D006 (cadmium), D007 (chromium), D008
(lead), D010 (selenium), and D011 (silver). No more than
160 tons of hazardous waste are permitted to be stored at the
facility at any one time, and HRD must submit a research
notification to EPA Region III in Philadelphia, Pennsylvania,
30 days before accepting any hazardous waste. The research
notification must include the purpose of the research, the
type and quantity of waste, and a residue management plan.
In addition, HRD must prepare and submit to EPA a report
detailing the effectiveness of all research activities and the
fate of all wastes and residuals from the HRD Rame Reactor
process.
The EPA RD&D permit restricts air emissions from the
HRD Flame Reactor facility, limiting dust emissions from
fabric filters on the storage silos and day bins as well as
emissions from the baghouse. Air emissions for the Flame
Reactor must also comply with permit number 04-308-028
issued by the Pennsylvania Bureau of Air Quality under the
authority of the Air Pollution Control Act of January 8,1960
[Public Law 2119], as amended.
In addition to the federal RD&D permit, HRD was granted a
Hazardous Waste Storage and Treatment Permit through the
Pennsylvania Department of Environmental Resources
(PaDER) in August 1990. This permit authorizes
management of hazardous waste for research, development,
and demonstration purposes. Specific permit conditions
include restrictions on operating conditions, types of wastes
treated, and storage of hazardous waste in containers, tanks,
and waste piles.
PaDER required HRD to submit a Module 1 permit
application for the waste storage and treatment activities
conducted during the SITE demonstration. This permit
identified the source, characteristics, and volume of waste
HRD treated during the demonstration. Both EPA and
PaDER authorized temporary waste pretreatment (drying
and crushing) for the SITE Demonstration.
14
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3.5.2 Federal ARARs
The U.S. Department of Transportation (DOT)
requirements for transporting hazardous waste must be met
when wastes are transported to the HRD Flame Reactor.
Transportation regulations apply to both research-scale or
commercial-scale operation of the HRD Flame Reactor. In
addition, Occupational Safety and Health Act (OSHA)
requirements [29 CFR Parts 1900 through 1926] provide for
the health and safety of workers at hazardous waste
treatment facilities and hazardous waste sites and must be
fulfilled at both the research-scale and commercial-scale
level of operation.
On August 21, 1991, the EPA BIF rule [40 CFR 266,
Subpart H] became effective. The HRD Flame Reactor is
classified as a smelting, melting, and refining furnace by the
BIF rule [56 FR 7143]. However, smelting, melting, and
refining furnaces that process hazardous waste solely for
metal recovery are conditionally exempt from the majority
of 40 CFR 266, Subpart H regulations, and therefore, need
only comply with 40 CFR 266.101 (Management Prior to
Burning) and 40 CFR 266.112 (Regulation of Residues).
These furnaces are conditionally exempt because 1) EPA
does not believe it prudent to regulate a whole potential
class of devices and wastes that it has not fully evaluated
and 2) EPA wishes to study further whether regulating these
furnaces under the Clean Air Act may be more appropriate,
specifically if technology-based controls on toxic air
emissions are likely to apply.
Even though EPA might classify the HRD Flame Reactor as
conditionally exempt, because the BIF rule promulgated
risk-based emission levels for metals and HC1, the state or
federal permitting authority could apply these standards by
imposing the omnibus authority of RCRA [40 CFR
270.32(b)(2) and RCRA Section 3005(c)(3)] to protect
human health and the environment. Therefore, the BIF
regulatory limits for metals, HC1, and paniculate emissions
are presented below.
The BIF rule established a three-tiered permitting structure
to control emissions of HC1, chlorine (C12), and 10 toxic
metals listed in Appendix VIII of 40 CFR 261. The list of 10
toxic metals is further broken down into four carcinogenic
metals (arsenic, beryllium, cadmium, and chromium) and
six noncarcinogenic metals (antimony, barium, lead,
mercury, silver, and thallium). Tier I of the three-tiered
permitting structure limits feed rates, Tier II sets emission
rate screening limits, and Tier III requires a site-specific
risk assessment. EPA expects the majority of facilities to
elect to comply with Tier III standards to obtain more
flexible permit limits.
Tier HI standards require 1) emissions testing to determine
the emission rate for each metal and 2) air dispersion
modeling to predict the maximum, annual, off-site, ground-
level concentration for each metal. These concentrations are
then compared to the acceptable ambient levels specified in
Appendix IV and V of the BIF rule [56 FR 7223]. The cost
and time estimates to perform Tier III metal emission
assessments are considerable. These calculations are both
waste and site specific and must be done on a case by case
base. Future HRD Flame Reactor work might not be done at
Monaca, Pennsylvania - and the calculations would have to
be redone. While this calculation is definitely deskable, its
cost is prohibitive and beyond the scope of this SITE
project. If the AAR reader is very interested in the HRD
technology, he can contact HRD and discuss concerns
before selecting this technology. Therefore, in this report
Tier II screening limits will be presented. These limits are
not the regulatory limits for the Flame Reactor and are
presented for comparison purposes only. In addition,
because the HRD stack is shorter than the Flame Reactor
building, and because the surrounding terrain within 5
kilometers (3.1 miles) of the stack equals or exceeds the
elevation of the physical stack height, the Tier II screening
limits presented below [56 FR 7229, 7230, 7232] are the
conservative (restrictive) limits.
Carcinogenic Metals Tier II Screening Limits
0.11 g/hr
0.26 g/hr
0.040 g/hr
0.20 g/hr
14 g/hr
2400 g/hr
4.3 g/hr
14 g/hr
140 g/hr
14 g/hr
,-2.
330 g/hr or 9.1 X 10'z g/sec
Arsenic
Cadmium
Chromium
Beryllium
Noncarcinogenic Metals
Antimony
Barium
Lead
Mercury
Silver
Thallium
HC1 and C1-,
HC1
C12
The HRD Flame Reactor may be subject to additional air
emissions regulations when the Clean Air Act Amendments
of 1990 are promulgated. The Clean Air Act Amendments
concerning hazardous air pollutants may potentially address
many of the same sources regulated under 40 CFR 266. For
example, the New Source Performance Standards (NSPS)
of Section 111 of the Clean Air Act may be ARARs for a
HRD Flame Reactor unit installed at a Superfund site,
especially if the pollutants emitted and the technology
employed are sufficiently similar to a pollutant and source
category regulated by the NSPS. Also, EPA has established
National Emissions Standards for Hazardous Air Pollutants
(NESHAPS) for arsenic, beryllium, and mercury for certain
categories of sources [40 CFR 61].
3.5.3 State and Local Regulations
State and local regulatory agencies may write permits that
are more stringent than the federal regulations. Therefore,
state and local regulations have to be evaluated on a case-by-
case basis.
15
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3.6 The Impact of Waste Characteristics
on the Performance of the Technology
Waste feed characteristics affecting the efficiency of the
HRD Flame Reactor include PSD, moisture content,
chemical composition, and fusion temperature.
HRD recommends that 80 percent of the waste feed should
be finer than 200 mesh (0.0029 inches or 75 microns);
however, waste feed with a PSD of up to 80 percent smaller
than 30 mesh (600 microns) has been processed. Coarser
waste feed may decrease efficiency and impede slag fusion,
both of which decrease the recovery of volatile metals.
HRD operates a hammermill for feed size reduction.
The recommended moisture content is less than 5 percent
total moisture; however, waste feeds with up to 15 percent
total moisture have been processed effectively. Low
moisture content requires less energy, and the gravity and
pneumatic feed system requires low moisture content for
reliable operation. HRD operates a steam-heated, hollow
auger unit for waste feed drying.
The chemical composition of the waste feed affects the
Flame Reactor's energy consumption, the reducing or
oxidizing condition in the reactor, and the possible need to
add a fluxing agent to achieve a more efficient process. The
type and concentration of volatile metals present in the
waste feed is another important characteristic of the
chemical composition. HRD recommends a total volatile
metal content of 5 percent or greater in order to produce an
oxide product with a reasonable metal content for recycling.
The fusion temperature or melting point of the waste feed
should be lower than 1,400"C to ensure that the waste will
melt. The slag separator operates between 1,400°C and
1,600"C. If the fusion temperature is too high, the effluent
slag will begin to solidify in the reactor. Fluxing agents can
be added to reduce the fusion temperature and viscosity.
3.7 The Impact of Operating Parameters
on the Performance of the Technology
The HRD Flame Reactor process can be adjusted to
regulate two control parameters: 1) the residence time of the
feed particles in the reactor and 2) the reducing conditions in
the reactor. These two control parameters are regulated by
the three operating parameters: 1) waste feed rate, 2) fuel
feed rate, and 3) oxygen content of combustion air. Optimal
conditions for these three operating parameters were
determined in the shakedown runs to achieve the desired
residence time and reducing conditions. The reactor
temperature is not a control parameter and it cannot be
measured directly. It can only be controlled indirectly by
manipulating one or more of the operating parameters.
The waste feed rate affects the residence time of the
particles in the reaction zone, as well as the quantity of
metal oxide in the off-gas. If the residence time is reduced
too much (that is, the feed rate is too high) the feed particles
will only partially reduce. Partial reduction of the feed
particles will lower the percentage of volatile metals
recovered in the oxide product and will produce a slag with
a higher concentration of volatile metals.
The fuel feed rate controls the source of the reducing gas
stream and the amount of energy available for feed fusion.
When the fuel feed rate is higher, more CO is present to
reduce the metals to elemental form; higher reducing
conditions in turn increase the percent recovery of volatile
metals. The combustion (oxidation) of the fuel provides the
energy for the fusion of the waste feed. Sufficient energy
must be provided to completely fuse the waste feed into a
fluid slag.
The 02 content of the combustion air affects 1) the
stoichiometric conditions that produce the reducing gas
stream and 2) the volume of the off-gas stream. Although
the fuel feed rate controls the source (CO) and the amount of
the reducing gas stream, the O2 content determines the
extent of oxidation of the fuel. A low O2 content produces
higher reducing conditions because not all of the fuel is
oxidized to CO2, and much of it remains as CO. A high O2
content produces lower reducing conditions, because most
of the fuel is completely oxidized to CO2. However, a high
O2 content decreases the volume of gas in the oxide product
collection system, because it lowers the volume of
combustion air required. The HRD Flame Reactor typically
operates at between 50 and 80 percent O2 (ambient air is 21
percent). During the demonstration, the O2 content
averaged 83 percent.
Although it is not a control parameter, the reactor
temperature affects the reaction rate. At higher temperatures,
reaction rates increase, allowing shorter residence times and
increased feed rates. However, higher reactor temperatures
increase heat losses, and high heat losses require more fuel
and O2 to maintain a given reaction temperature.
3.8 Materials Handling Required by the
Technology
HRD performs all materials handling at the HRD Flame
Reactor facility. If necessary, the waste is pretreated to
achieve optimal PSD and moisture content, before being
transferred to the day bins. During treatment in the Flame
Reactor, the waste feed, fuel, O2, and compressed air
entering the system must be fed and metered. After
treatment, both effluent streams require special handling.
Waste feed pretreatment consists of drying and reducing the
particle size. Following pretreatment, waste feed is placed
in portable storage bins that are stored adjacent to the
reactor building until required. The waste feed is
mechanically conveyed from the portable bins to the day
bins located above the reactor in the Flame Reactor building.
During treatment, the waste feed is metered by screw
conveyors and pneumatically injected into the reactor.
Natural gas or another fuel source, O2, and compressed air
are metered into the reactor. O2 is stored on site as a
cryogenic liquid in a 9,000-gallon storage tank; natural gas
16
-------
is supplied by the local utility company through a pipeline;
and compressed air is supplied by a rotary compressor
located adjacent to the Flame Reactor building.
The oxide product requires special handling because of its
high heavy metal content. The oxide collection system
collects the oxide in 1.5-cubic-yard bulk storage bags
(supersacks) filled directly from the conveyor to minimize
worker dust exposure. When one supersack becomes full,
the conveyor begins to fill another. After the supersack is
removed from the recovery system, the sack can manually
be closed to prevent dust from escaping.
The effluent slag requires special handling because of its
extreme heat. The effluent slag is about 1,400°C when it is
tapped from the separator. It falls onto a 25-foot-long,
vibrating, water-cooled conveyor. At the end of the
conveyor, the slag, now about 600 to 800°C, drops into a
metal collection bin. When the collection bin is full, a
forklift moves it to the storage building for additional
cooling.
3.9 Community Impact
Because the facility is located in an industrial area, the
impact of the HRD Flame Reactor on the community
surrounding the HRD facility is minimal. The hazards to the
community may include the following:
• Stack emissions
• Dust releases
• Transportation hazards
Stack emissions from the Flame Reactor are low and will be
reduced even further when new emission control equipment
is purchased. Dust releases from both pretreatment and
Flame Reactor processing are minimal due to the dust
control equipment used at the facility. Transportation
hazards are minimal, because the waste feeds are typically
solids and are generally stored in closed containers.
3.10 Personnel Issues
During test program operations, the HRD Flame Reactor
operates two 8-hour shifts per day. A shift supervisor, two
operators per shift, and a mechanic are needed to run the
HRD Flame Reactor plant. At the HRD Flame Reactor
facility, self-extinguishing coveralls, half-face respirators,
hard hats, steel-toe shoes, and safety glasses are required; in
addition, hearing protection is suggested. Special protective
clothing is required to protect the worker at the slag tap hole
from the intense heat. Safety showers, emergency eye-wash
stations, first aid kits, and fire prevention equipment are
located throughout the facility.
The HRD Flame Reactor contains many safety features in its
design. The system is designed to automatically shut itself
down when problems occur or when the range of
predetermined operating conditions is exceeded. Nitrogen
can be introduced into the Flame Reactor system instantly to
displace air and C>2 if explosive conditions ever occur.
Explosive conditions might occur if the burner system
failed to ignite.
17
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-------
Section 4
Economics
One goal of the SITE program is to develop reliable cost
data for innovative and commercially available hazardous
waste treatment. Cost data for the HRD Flame Reactor
technology were obtained primarily from HRD. Other
sources of cost information included EPA experience and
the SITE demonstration. The costs associated with the HRD
Flame Reactor technology have been placed into the 12 cost
categories applicable to typical cleanup activities at
Superfund and RCRA corrective action sites. These cost
categories are defined and discussed in this section as they
apply to the HRD Flame Reactor technology. Table 4-1
presents estimated costs per ton for waste treated by six
HRD Flame Reactor scenarios. These six scenarios are
divided into the SITE Demonstration test operating
conditions (Scenario 1) and five commercial operating
scenarios (Scenarios 2 through 6). Scenarios 1, 2, and 4 are
based on waste treatment at the HRD facility in Monaca,
Pennsylvania, and Scenarios 3, 5, and 6 are based on
treatment at the waste location. Costs presented in this
analysis are order-of-magnitude estimates (-30 to +50
percent) and are rounded to the nearest dollar.
4.1 Site-Specific Factors Affecting Cost
A number of factors affect the cost of the HRD Flame
Reactor system. These factors are highly site-specific and
rather difficult to quantify without accurate data from a site
remedial investigation report or waste profile. Factors
affecting costs generally include 1) the volume of waste to
be treated; 2) waste characteristics such as waste feed PSD,
moisture content, and type and concentration of
contaminants in the waste; 3) the distance the waste must be
transported to the HRD Flame Reactor; 4) treatment goals to
be met; and 5) frequency of equipment repair and
replacement.
4.2 Basis of Economic Analysis
The HRD Flame Reactor technology can be applied to
several types of wastes, including granular solids, soil, flue
dust, slag, and sludge containing heavy metals. This
economic analysis is based on SLS slag as the waste feed to
be treated. It should be noted that all the cost categories for
the secondary lead slag scenario may not apply to other
types of waste. Therefore, when estimating the costs for a
given scenario, only applicable categories should be used.
For the purpose of this economic analysis, the HRD Flame
reactor is assumed to operate 24 hours per day, 7 days per
week, operating 85 percent of the time. Therefore, 6,700 tpy
(Scenarios 1 through 3), 13,400 tpy (Scenario 4), 20,000 tpy
(Scenario 5), and 50,000 tpy (Scenario 6) correspond to 0.9,
1.8,2.7, and 6.7 tons of waste feed per hour, respectively.
Also, the HRD Flame Reactor unit is assumed to have a 10
year life.
For this analysis, certain assumptions, derived from the
HRD SITE Demonstration, were made regarding the waste
feed and the operating conditions. Assumptions regarding
waste transportation apply only to treatment at the HRD
Monaca facility (Scenarios 1, 2, and 4) and not to on-site
treatment at a waste site (Scenarios 3, 5, and 6). These
assumptions include:
Assumptions Regarding the Untreated Waste Feed
• Waste must be excavated at the site.
• The hazardous waste site is within 750 miles of the
HRD facility in the Monaca, Pennsylvania, scenarios.
• The particle size of the raw waste will require size
reduction to less than 200 mesh for the commercial
scenarios. The largest particle size in the demonstration
test was 30 mesh.
• The moisture content of the waste is between 15 and 25
percent, and the waste must be dried to 5 percent total
moisture.
• The waste is primarily contaminated with heavy metals
(such as lead and cadmium) at levels up to 7.5 percent.
• No pretreatment of the waste is required, other than
crushing or grinding, drying, and screening.
Assumptions Regarding the Operating Conditions
• Technicians will collect all samples and perform
equipment maintenance and minor repairs.
• Labor costs associated with major equipment repairs or
replacement are included.
• Waste feed rates for the system varies between 0.9 and
6.7 tons per hour in the scenarios.
• Fuel to waste feed ratio for the system is 8.4 to 23.1
thousand cubic feet (mcf) of natural gas per ton.
19
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Tabfa 4-1. Estimated Costs Associated With HRD Flame Reactor Systems
Operating Scenario
SITE Test
Commercial Operations (scenarios 2-6)
Scenario Number
Plant Location
Capital ($ million)
Annual Capacity (tons)
Cost Categories
Site Preparation
Excavation of Waste
Transportation of Waste
Pretreatment of Waste
Permitting and Regulatory
Requirements
Capital Equipment
Startup
Labor
Consumables
Oz
Natural Gas
Utilities
Effluent Monitoring *
Shipping, Handling, and Transporting
Residuals
Effluent Slag
Oxide Product b
', Analytical Testing
Equipment Repair and Replacement
Site Demobilization
Total Cost Per Ton Waste
1
Monaca
2.5
6,700
93
129
246
to
64
1
114
131
81
11
0
15
-
3
34
0
$932
2
Monaca
2.5
6,700
Estlmal
10
" 60
21
/ 10 "
>
64
1
78
'*-¥!*!
93
58
11
b "
15
-
3
34
0 ,,
$458
3
On-Site
3.1
6,700
led Costs per Ton of
v^ws,-;
10
- s 6-. - -
21
••VAST, o ^^,?1Q t fff^Jf
«&/&v£4& •^'<-'f'-'f -, ' '
79
,„,„, 1 vrF«>"
93
''V " * -V! **< '•
93
58 ;,,;,/},;„
11
'"'" " 0 s;v.,.
-
37
"T"*! 10 --•"•><•"'''
$448
4
Monaca
4.5
13,400
Waste Tr
- **>&*',{
10
60''°-'
20
:;;fc
58
1
39
'. ,?%%.
60
34
11
, 0;""'
15*" *
-
2, ,,
30
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$350
5
On-Site
6.0
20,000
eated (1991 $)
-*v-r .-
10
v=V< 6 v'
19
' '"^'IQ"',"!
;-^A:«-;-, "!^
52
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49
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11
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15
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,- " ' 2' '-
24
'*'" 7,,,,,
$263
6
On-Site
10.4
50,000
' "' '
10
•'*/!'' fjf f£
17
^ ;,io-:-;
36
-"-'V - 1
18
41
21
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' '?,',*< 4fff>t> ft* ' ' f
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-------
ton for excavating the waste with a backhoe and loading the
waste into 1-cubic-yard bulk sacks and 2) $129 per ton for
transporting 72 tons of the waste 750 miles to the HRD
facility. In the commercial scenarios, excavation cost are
significantly reduced by economy of scale.
Costs for commercial-scale pretreatment differ significantly
from costs for the demonstration test. Commercial scale
pretreatment costs totalled $246 per ton and included $200
per ton for labor, $13 per ton for utilities, and $33 per ton for
rental of a waste feed dryer and hammermill. Commercial
scale pretreatment equipment will reduce pretreatment costs
by reducing labor costs.
4.2.2 Permitting and Regulatory Costs
Permitting and regulatory costs will vary depending on
whether treatment is performed on a Superfund or a RCRA
corrective action site and the fate of the treated waste.
Section 121(d) of the Comprehensive Environmental
Response, Compensation, and Liability Act (CERCLA), as
amended by SARA, requires that remedial actions be
consistent with ARARs of environmental laws, ordinances,
regulations, and statutes. ARARs include federal standards,
as well as more stringent standards promulgated under state
or local jurisdictions. ARARs must be determined on a site-
specific basis.
The HRD facility is a permitted RCRA treatment, storage,
or disposal (TSD) facility. The cost of keeping up with
applicable regulations is estimated to be about $10 per ton
for all cases. Permitting and regulatory costs for waste and
treatment residues transported to and from the facility are
not included in this estimate.
4.2.3 Capital Equipment Costs
Capital equipment costs include the cost of the HRD Flame
Reactor and the required auxiliary equipment. The capital
costs shown in Table 4-1 are based on information provided
by HRD and assume financing at 12 percent per year over 10
years.
4.2.4 Startup Costs
Startup costs for the HRD Flame Reactor scenarios include
purging the system and establishing operating parameters
for the waste stream. These costs would be primarily for
labor. Purging the system could also be considered
demobilization from the previous run; therefore, startup
costs are estimated to be about $1 per ton of waste treated
and, for treatment at Monaca (Scenarios 1, 2, and 4), no
demobilization cost is required. This cost is based primarily
on labor costs for five technicians working three shifts each
on 3 operating days for this activity.
On-site startup costs are based on 1 month of labor costs and
are spread over a 10 year plant life. Actual costs would be
case specific and would vary with site conditions and the
length of the remediation period.
4.2.5 Labor Costs
HRD estimates a Flame Reactor operating crew of three
workers per shift for the 50,000 tpy scenario (Scenario 6),
and two workers per shift for other scenarios. One
mechanic and one supervisor are required, except for the
50,000 tpy plant, where two mechanics are required. Two
additional workers are added to the on-site scenarios to
handle reporting and clerical needs. All personnel work a
40-hour week at an average hourly rate of $25.
4.2.6 Consumable Costs
Consumable costs for the HRD Flame Reactor system
include costs for O2 and natural gas. The quantities used will
depend on the waste feed rate, the O2 content of the
combustion air, the reactor temperature, and the scale of
operation. The commercial scenarios assume bulk pricing at
$2.50 per incf for both O2 and natural gas (compared to
$3.50 per mcf for noncommercial scenarios). The
consumable costs are estimated to be approximately $41 to
$131 per ton of O2, and $21 to $81 per ton of natural gas.
4.2.7 Utility Costs
The HRD Flame Reactor system requires 480-volt, three-
phase electric power. The electric power requirements will
be primarily for motors and pumps in the system. Electric
power cost is estimated at $11 per ton for all scenarios.
Water costs are considered negligible, because water is
recycled in the system.
4.2.8 Effluent Monitoring Costs
This cost category covers monitoring the system's air
emissions according to the facility's air permit. Effluent
monitoring will be performed by the HRD Flame Reactor
system operators. Effluent will be discharged to the
atmosphere according to limits set by local and state
regulations. Costs for monitoring effluent are included in
capital and labor cost categories.
4.2.9 Residuals Shipping, Handling, and
Transportation Costs
The HRD Flame Reactor system produces an oxide product
and an effluent slag that require special handling and
disposal. Costs for this disposal will depend on geographic
location, distance from the site to the permitted landfill, as
well as other factors such as the concentrations of regulated
metals in the oxide product and effluent slag.
Residual slag shipping, handling, and transportation costs
are based on the generation of about 30 tons of slag per 100
tons of waste treated. The estimated disposal cost is
approximately $15 per ton of waste treated. The actual
disposal cost is $45 per ton of effluent slag and includes
transportation, disposal, and other customary charges for
transportation and disposal of the effluent slag to a sanitary
waste landfill within 100 miles of Monaca, Pennsylvania.
21
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The oxide product from the baghouse was collected and
analyzed and subsequently can potentially be recycled for
recovery of its lead content. There may be a cost involved hi
recycling the lead oxide dust. This cost depends on the
current lead market (supply and demand for lead), the
concentration of lead as well as impurities or contaminants
in the material to be recycled, the amount of oxide product,
and the cost of handling the oxide product. It should be
noted that the amount of oxide produced during the
demonstration was approximately 25 weight percent of the
total dried waste feed.
4.2.10 Analytical Costs
Analytical costs include those for laboratory analysis, data
reduction and tabulation, QA/QC, and reporting. These costs
are for verification of treatment effectiveness and do not
include waste characterization. Analytical costs will vary
according to the types of contaminants and regulatory
requirements for the waste.
This analysis assumes that daily composite samples of
oxide product and effluent slag will be collected and
analyzed for the major species of concern (such as lead)
using energy dispersive x-ray fluorescence. Weekly
composite samples will also be collected and analyzed
using TCLP, depending on the customers' request. This
results in analytical costs of about $1 to $4 per ton of waste
treated.
4.2.11 Equipment Repair and Replacement Costs
During the course of operation, some parts of the system
may require repair or replacement. For this analysis,
equipment repair and replacement costs vary from 9 percent
of capital costs or about $34 per ton of treated waste for the
6,700 tpy scenarios (Scenarios 1 through 3) to 7 percent of
capital for the 20,000 and 50,000 tpy scenarios (Scenarios 5
and 6, respectively). This cost includes any major repairs or
replacements.
4.2.12 Site Demobilization Costs
Site demobilization normally includes items such as
operation shutdown and decommissioning of equipment, site
cleanup and restoration, and disconnection of utilities. The
HRD Flame Reactor facility at Monaca will not be
decommissioned after treating the waste and this cost
category would only involve purging the system. This
purging can also be considered startup costs for the
subsequent run. Therefore, for the Monaca scenarios,
demobilization costs are included in startup costs.
For the on-site scenarios, demobilization includes 6 months
of labor and other decommissioning costs spread over a 10-
year operating life.
4.3 Summary of Economic Analysis
Considering the 12 cost categories and the assumptions
made in this economic analysis, the estimated cost per ton
for treating SLS slag ranges from $932 for the SITE
Demonstration (Scenario 1) to $208 for a 50,000 tpy
scenario (Scenario 6), which includes a waste pretreatment
system for more efficient waste processing in the HRD
Flame Reactor. The waste pretreatment system increases
capital costs per ton of waste treated by about 36 percent;
however, this system decreases pretreatment costs by 91
percent, labor costs by 50 percent, consumables costs by 43
percent, and equipment repair and replacement costs by 12
percent HRD expects to have the pretreatment system for its
Flame Reactor in place by 1992.
As mentioned earlier in this section, costs presented in this
analysis are order-of-magnitude estimates (-30 to +50
percent) and are rounded to the nearest dollar. Also, factors
that affect the estimated cost of the HRD Flame Reactor
system are highly site-specific and rather difficult to
identify without accurate data from a site remedial
investigation report or waste profile. Variability in the waste
characteristics, in the costs of transporting waste to the HRD
Flame Reactor, and in transporting, shipping, and handling
residuals could significantly affect costs presented in this
economic analysis.
22
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References
Federal Register (FR), 1991, Burning of Hazardous Waste in
Boilers and Industrial Furnaces: Final Rule. Volume
56, No. 35, pp. 7134-7240 (February 21).
Horsehead Resource Development Company, Inc., 1989,
FLAME REACTOR Process - A High Temperature,
Gas-Fired Flash Smelting Process, a proposal in
response to U.S. EPA RFP-004 (March).
Horsehead Resource Development Company, Inc., 1990,
Sample analyses from NSR site (July).
U.S. Environmental Protection Agency (U.S. EPA), 1992,
Technology Evaluation Report. SITE Program
Demonstration of the Horsehead Resource
Development Company Flame Reactor Technology, to
be published.
23
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Appendix A
HRD Flame Reactor Process Description
25
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Appendix A
HRD Flame Reactor Process Description
A. 1 Background
The Horsehead Resource Development Company, Inc.
(HRD) Flame Reactor process is designed to thermally treat
metal-containing solids, soil, flue dust, slag, and sludge.
The treatment process yields two products: a heavy metal-
enriched oxide product that can potentially be recycled by
metal producers and a vitrified slag that can potentially be
used as an aggregate. The HRD high-temperature reactor
processes wastes with a very hot reducing gas produced
from the combustion of solid or gaseous hydrocarbon fuels
in below stoichiometric O2-enriched air. Upon injection into
the reactor, the feed materials are believed to react in less
than 0.5-second, allowing a high waste throughput
Volatile metals, such as cadmium, lead, and zinc, in the
waste material are vaporized and captured downstream in a
product dust collection system. Nonvolatile metals, such as
chromium, iron, and nickel, are encapsulated in the slag.
For good reaction conditions, the particles should contain
less than 5 percent total moisture, and at least 80 percent of
the feed should be less than 200 mesh. Also, the feed
material's fusion temperature should not exceed 1,400°Q.
Variations from these specifications are acceptable but tend
to decrease throughput and reduce the percent recovery of
metals in the oxide product.
Figure A-l presents the process flow diagram for the HRD
Flame Reactor process. The process consists of five
sections: ,
• Feed System
• HRD Flame Reactor
• Slag Separator ]
• Combustion Chamber
• Oxide Product Recovery System
The five sections are discussed below.
A.2 Feed System \
Feed system operations include 1) waste feed and solid fuel
storage and handling, 2) metering and injection of waste
feed and fuel into the reactor, and 3) metering and injection
of O2 and air.
The solid material storage and handling system consists of
storage facilities, portable bins, day bins, and a pneumatic
conveying system. The waste material to be fed into the
reactor can be delivered to the site by rail or by truck. The
waste material is stored in a storage building next to the
Flame Reactor building prior to processing. If pretreatment
of the waste (drying and crushing) is necessary, the waste is
transferred to another building that contains the pretreatment
equipment. After pretreatment, a loader empties the feed
material into portable bins, which are moved to the HRD
Flame Reactor building. From the portable bins, waste is
transferred to the day bins by placing the portable bin on a
discharge stand and opening the bottom discharge slide-gate
of the portable bin. Dusting is controlled by a seal located
between the gasketed opening of the stand and the flange of
the portable bin slide-gate. The waste is fed into a screw
conveyor that empties into the tubular, day bin filling
system.
Of the three day bins, two are used for waste, and one is
used for solid fuel. Normally, solid fuel such as coal fines
can be used to reduce costs; however, natural gas was
chosen for the SITE demonstration because 1) it is more
likely to be used in a site remediation and 2) it has a uniform
composition. Each day bin has a capacity of 150 cubic feet
and is mounted on a set of three, shear-beam, load cells that
measure the day bin weight for inventory and process
control. Material from each day bin is pneumatically
injected into the reactor.
To calculate waste feed rate, the process control system
records the loss of weight over time. The system uses a 10-
minute average waste feed rate to control the feed system.
Material is discharged from a day bin, through a live-
bottom feeder, into a surge hopper set above a variable speed
screw feeder with a rated capacity of 60 pounds per minute.
The feeder accurately controls the flow of material into the
reactor via a 2-inch, pneumatic injection line.
The gases used in the SITE demonstration were ©2,
ambient air, and natural gas. O2 is stored on-site as a
cryogenic liquid in a 9,000-gallon storage tank. The O2 is
used to enrich the ambient air for combustion. Compressed
air produced by a compressor, operating at 1000 standard
cubic feet per minute (SCFM) at 40 pounds per square inch
(psi), is used to convey the solid feeds to the reactor and to
combust the fuel. Natural gas, supplied by pipeline from the
local utility company, was used as the fuel during this
26
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WASTE FEED
COMBUSTION AIR
COMPRESSOR
OXYGEN
STACK
GAS
EXHAUST
EFFLUENT
SLAG
SOURCE: HowhMd R*»ourc* Development Company, Inc.
Figure A-1. HRD Flame Reactor Process Schematic.
demonstration. A 6,000-gallon liquid N2 tank is also on-
site, but it was not used in the demonstration. The N2 is used
to blanket coal fines as an added safety feature when coal is
used as the fuel source.
A.3 HHD Flame Reactor
The HRD Flame Reactor, shown in Figure A-2, is a two-
stage system consisting of a fuel burner system (first stage)
and the metallurgical reactor (second stage). Carbon-based
combustion and gasification reactions occur in the burner
system, followed by metal smelting reactions in the
metallurgical reactor. The reactor is 15 feet tall, positioned
vertically, with an internal diameter of 23 inches.
The first stage of the Flame Reactor is a fuel burner system
consisting of a mixing head, upper pilot, lower pilot, and gas
injection chamber. In the mixing head, fuel and O2-enriched
air (typically 50 percent to 80 percent O2 by volume) are
mixed. This mixture then ignites in the upper pilot and is
stabilized by expansion into the lower pilot. Injecting O2-
enriched air in the gas injection chamber helps control the
reducing conditions, adjust the stoichiometry (CO:CO2
ratio), and further stabilize the flame in the Flame Reactor.
Because highly O2-enriched air is used, flame temperatures
greater than 2,000°C are realized in the Flame Reactor. A
different burner design is employed when solid fuel is used
as the energy source.
Fine, dry, waste feeds containing metals are metered with a
screw feeder and pneumatically injected into the reactor
(second stage) at a location just below the exit of the burner
(see Figure A-2). The waste feed reacts in the high-
temperature, reducing gas stream. CO from the incomplete
combustion of the fuel reduces the metal compounds in the
waste feed by the following reactions:
Combustion of natural gas (CH4)
CH4 + 3/2O2 -> CO + 2H2O
CH4 + 2O2 -» CO2 + 2H2O
CH4 + CO2 + 02 -> 2CO + 2H2O
CH4 + 1/2O2 -» CO + 2H2
Reduction/Smelting of Volatile Metals
Iron: Fe3O4 + CO -> 3FeO + CO2
Zinc: ZnO + CO -» Zn (vapor) + CO2
Cadmium: CdO + CO -» Cd (vapor) + CO2
Zinc-Iron: ZnFe2O4 + 2CO -» Zn (vapor) + 2FeO + 2CO2
Lead: PbSO4 + 2CO -> Pb (vapor) + SO2 + 2CO2
Lead: PbSO4 + CO -> PbO + SO2 + CO2
The nonvolatile components of the waste feed fuse, forming
the efrluent slag.
27
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OXYGEN-ENRICHED AIR
NATURAL GAS
OXYGEN-ENRICHED AIR
WASTE FEED
SOURCE: Horulwad Davtlopflunt Company, Inc.
Figure A-2. HRD Flame Reactor.
MIXING HEAD
UPPER PILOT
LOWER PILOT
GAS INJECTION
CHAMBER
BURNER
|— SYSTEM
(STAGE I)
FEED INJECTION
CHAMBER
REACTOR
SAMPLING
CHAMBER
METALLURGICAL
— REACTOR
(STAGED)
TRANSITION SECTION
(TO SLAG SEPARATOR)
The energy required for fusion and reduction lowers tjhe
temperature to between 1,500°C and 1,700°C. At this
temperature, several elemental metals are ahove their boiling
point (see Table A-l) and volatilize into the gas stream with
the O2 and CO2- Recovery of cadmium, lead, and zinc is ;of
particular interest because of their economic value.
The reactor vessel is water-cooled to assure that a layer of
the molten slag solidifies on the inner reactor walls. The slag
layer protects the reactor walls from intense heat and
reduces the reactor heat losses. Molten material is conveyed
down the reactor walls by gravity and by the combustion
gases. At the end of the reactor, the molten metal'is
accelerated through a tapered transition section into the
horizontal slag separator. \
A.4 Slag Separator
The reactor continuously discharges material into a
refractory-lined, water-cooled cyclonic separator that
separates molten slag from reactor off-gases. Off-gases
contain mainly CO, hydrogen (H2)> and any metal vapors
recovered from the waste feed. The effluent slag contains 35
to 75 percent of the mass of metals from the waste feed.
The slag separator is positioned horizontally between the
flame reactor and the combustion chamber (see Figure A-l).
The gases, particulate, and metal vapors flow toward the
combustion chamber, countercurrent to the slag. The molten
slag runs out through a tap hole on the discharge end of the
unit. Occasionally a small amount of effluent slag is carried-
over to the combustion chamber.
A.5 Combustion Chamber
The slag-free reactor off-gases are combusted again with air
in a refractory-lined combustion chamber. The metal vapors
oxidize and condense as solids, while combustible gases
such as CO and H2 are burned. The gas stream from the
combustion chamber includes metallic oxides, CO2, water
28
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Table A-1. Boiling Points of Metals and Compounds of Interest
Metal
Aluminum. " ^\" ;*. :
Antimony
Barium
Catfrrturn >£,,-, ", '--t;
Calcium
^Chromium ,,.; " - ;* ';-\
Copper
Lead
- Magnesium •..-*„ "''"" :
Mercury
Boiling Point CC)
, ,,r -2,407- ;-;. '"
1,380
1,640
T >4,- %,-!-^-/^ -.
1,490
2,600
1,740
"r- -»", ,,i,iib""" , ;,
357
Nickel;
Potassium
•Seleniunf' 7 '';; T c<% '-, -
Silver
^'Sodium -V:v ' ' - -K ~
' p'* , ' t •.
Thallium
Zinc
774
.- "'*"*/eaB,7v\-f''. ,..(
1457
907
Source: CRC Handbook of Chemistry and Physics. 72nd
Edition, 1991-1992
(H2O), sulfur trioxide (SO3), and NOX. For the SITE
demonstration, the temperature of the off-gases after the
combustion chamber was typically between 700 and
1,000°C. Reactions in the combustion chamber include:
CO + 1/2O2 -> CO2
H2+1/2O2-»H2O
Metal (vapor) + 1/2O2 -^ MetalO
S02+1/2O2-*SO3
MetalO + SO3 -> MetalSO4
N2 + xO2->2NOx
A.6 Oxide Product Recovery System
The oxide product (MetalO) recovery system is designed to
cool the gas stream and capture the metal oxides formed in
the combustion chamber. The system consists of a heat
exchanger, a damper, and a baghouse for dust collection. An
induced draft fan, located between the baghouse and the
stack, provides the power for the system.
The gas is cooled by a shell-and-tube heat exchanger and by
the addition of ambient air. The heat exchanger has water
on the shell side and hot gases on the tube side. Because of
the typically high paniculate level in the gas stream, the heat
exchanger tubes require frequent cleaning. The addition of
ambient air is controlled by a damper. The damper is located
just before the baghouse and is used to maintain the
baghouse temperature below 200°C.
The dust collection system is a jet-pulsed baghouse designed
to recover metal oxide product from the gas stream. The
collection system emits off-gases through the plant stack and
discharges metal oxide product into enclosed bulk storage
bags for recovery. A rotary air lock, screw conveyors, and a
sealed boot connection reduce the possibility of fugitive
emissions. The baghouse collects the oxide product dust on
8,900 square feet of cloth.
The bag cleaning procedure consists of short, high-pressure
pulses of air through the bags to dislodge the particles
trapped on the surface. The pulses are initiated on a timed
cycle based on typical gas flow rates and dust loadings. The
particles fall by gravity into a screw conveyor below the
bags. The screw conveyor moves the particles to an oxide
product collection system composed of two bulk storage
bags. While one storage bag is filling, the other can be
removed and replaced with an empty storage bag.
The oxide product from the baghouse contains
approximately 25 to 65 percent of the mass of the waste
feed. Specific recoveries for volatile metals are generally
very high. Based on past testing, the baghouse oxide product
accounts for greater than 90 percent of the volatile metals in
the waste feed. The remainder is encapsulated in the
effluent slag, with a minimal fraction lost to the atmosphere
as stack emissions.
References
CRC, 1991, CRC Handbook of Chemistry and Physics,
Chemical Rubber Company, 72nd Edition, 1991-1992.
29
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Appendix B
Vendor's Claims for the Technology
31
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Appendix B
Vendor's Claims for the Technology
Note: This appendix to EPA's Applications Analysis Report
was prepared by Horsehead Resource Development
Company, Inc. Claims and interpretations of results in this
Appendix are those made by the vendor and are not
necessarily substantiated by test or cost data. Many of
HRD's claims regarding cost and performance can be
compared to the available data in Section 4 and Appendix C
of the Applications Analysis Report.
B.1 Process Description ;
The Horsehead Resource Development Company, Inc.
(HRD), Flame Reactor technology is an intense treatment
process for metal-containing materials with proven
capabilities for the following:
t
• Metal recovery and recycling
• Slag vitrification
» Organic chemical destruction
The technical and economic advantages of the Flame
Reactor have been demonstrated in commercial-scale
testing of a wide variety of metal-bearing materials at the
HRD Flame Reactor demonstration plant in Monaca,
Pennsylvania.
The HRD Flame Reactor Process employs a two-stage,
high-temperature system to recover metals from wastes and
residues. Carbonaceous fuel (pulverized coal or coke, or
natural gas) is combusted with oxygen-enriched air under
fuel-rich conditions in the first stage, or burner section. In
the second stage, or reactor section, fine, dry feed is
pneumatically injected into the hot (2,200 to 2,5008C)
reducing flame. The intense process conditions allow short
reaction times (less than 0.5 second) and permit a high waste
throughput. Close control of the operating parameters anjd
the reactor gas composition enables separation of valuable
metals from the gangue components, as well as destruction
of hazardous organic constituents. i
The process temperature inside the reactor section is
typically around 1,650'C, but may vary between 1,400 and
1,850*C. In the high-temperature reducing atmosphere,
metals such as zinc, lead, arsenic, and cadmium are
vaporized from the waste, along with volatile components
such as alkali and halide compounds. Less volatile metals
such as copper, nickel, and cobalt, if present in sufficient
quantities, coalesce as a molten alloy. The remaining
components of the waste, including some metal oxides (such
as those of iron) melt into a molten effluent slag.
The reactor feeds directly into a slag separator, or horizontal
cyclone, where the process gases and volatile compounds
are separated from the molten materials. The effluent slag is
continuously tapped and solidified on a noncontact, water-
cooled, vibrating conveyor. The conveyor transports the
effluent slag to a temporary collection bin, from there it is
transferred to storage.
The process gases are drawn from the slag separator
through the oxide product collection system, where the
metal vapors are combusted again with ambient air and are
condensed as metal oxides; all remaining hydrogen (H2)
and carbon monoxide (CO) are combusted to water vapor
and carbon dioxide (CO2). The gases are subsequently
cooled, and the mixed metal oxide paniculate is collected in
a pulse-jet baghouse. A clean off-gas is discharged to the
atmosphere.
Accurate metering of the fuel, combustion air, and
feedstock maintains sufficient reducing conditions in the
reactor. The reducing conditions in the reactor form
metallic zinc, cadmium, and copper and leave iron as a
reduced oxide. Controlling of the oxidation-reduction
reactions offers several advantages. Volatile metals such as
zinc and cadmium are readily extracted from the waste as
metallic vapors, and condensable metals like copper can be
separated from the molten slag as a molten alloy. Reducing
iron to the oxide state, FeO, produces a more fluid and
therefore more easily tapped slag than would otherwise be
produced. Also, the metal alloys have a higher economic
value without high levels of iron contamination.
For optimal Flame Reactor performance, the feed material
should be very fine and contain little or no moisture. At a
minimum, the feed characteristics should allow trouble-free
pneumatic injection into the reactor. Moisture and particle
size also affects reactor performance. As moisture or particle
size increase, heat transfer rates and reaction rates are
reduced.
The Flame Reactor processes waste most effectively and
efficiently when 80 percent of the waste is less than 75
microns (200 mesh) and the total water content (including
chemically bound water) is less than 5 percent. However, the
32
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Flame Reactor has successfully processed material with
only 80 percent of the waste feed less than 1,000 microns
with 15 percent total water.
The Flame Reactor process does not require a minimum
metal concentration in the feed for effective treatment. Even
at very low metal concentrations, the Flame Reactor can
render a material nonhazardous by immobilizing the metals
in a vitrified effluent slag. However, in order for the metal
oxide product to be sufficiently enriched for recycling, the
total concentration of volatile metals, (such as cadmium,
lead, and zinc) should be at least 5 percent. Likewise,
condensable metals such as copper, nickel, and cobalt
should total 5 percent or more in the feed in order to yield a
molten metal alloy product.
The effluent slag produced during processing must be easily
tapped from the slag separator. Therefore, the slag must be
molten at 1,400 to 1,500°C and should have a viscosity of 2
Poise or less. If necessary, fluxing agents such as sand can
be blended with the feed prior to processing.
B.2 Advantages of the Flame Reactor
Process
HRD's Flame Reactor technology is uniquely suited to the
recovery and recycling of metal contaminants from a
variety of wastes and residues, and it is adaptable to
different feed characteristics and remediation scenarios. This
operating flexibility is possible because of the process
thermodynamics, controlled metering of process inputs, and
reliable analysis of process feed and product streams.
The extremely high processing temperature makes the
Flame Reactor technology suitable for treatment
applications involving the destruction of organic
compounds and vitrification. However, the real strength of
the technology is its ability to process waste containing
metal constituents, which are then recovered in a
concentrated form and can be recycled or sold to the
secondary metals market. Because the HRD Flame Reactor
recovers metals and destroys organic compounds, the
technology is able to produce a nonhazardous product from
a hazardous waste feed, eliminating hazardous waste
liabilities.
The principal technical and economic advantages offered by
HRD and the Flame Reactor technology are presented
below.
1. The HRD Flame Reactor process recovers recyclable,
metal-enriched products. The hazardous heavy metal
components of the waste are separated into these metal
products, eliminating hazardous waste generator
liabilities. The value of the recyclable products typically
offsets a portion of the processing costs.
2. The HRD Flame Reactor process produces a
nonhazardous effluent slag. The effluent slag meets all
Toxicity Characteristic Leaching Procedure (TCLP)
regulatory requirements and can be used in various
traditional aggregate applications.
3. Hazardous organic compounds are efficiently destroyed.
Organic compounds are readily combusted in the high
process temperatures, making the HRD Flame Reactor
suitable for treating metal-bearing wastes that are also
contaminated with hazardous organic chemicals.
4. HRD has experience in metal recovery and recycling.
HRD is co-owned by Horsehead Industries, Inc., and
Berzelius Umwelt-Service AG, a subsidiary of
Metallgesellschaft AG of Germany; each have over a
century of experience in the nonferrous metal industry.
5. The HRD Flame Reactor can be operated over a range
of operating parameters. The possible range of
operating conditions are presented in the table below.
Because the HRD Flame Reactor is flexible over a wide
range of parameters, operation can be tailored to treat
specific feeds, optimizing process performance and
economics.
Range of Flame Reactor Operating Conditions
Operating temperatures 1,350 to 1,850°C
Combustion air oxygen enrichment 50 to 80 percent
Waste feedrate 0.5 to 5 tons per hour
Plant capacity 5,000 to 60,000 tons per year
CO/CO2 ratio 0.1 to 2.0
6. The HRD Flame Reactor can utilize a variety of fuels.
Fuels successfully used in the HRD Flame Reactor
include the following:
« Natural gas
« Liquefied natural gas
• Low British thermal unit (Btu) coal
« High Btu coal
« Metallurgical coke fines
• Petroleum coke
7. HRD Flame Reactor process applications can be
expanded by using standard process technology. A
variety of drying and size-reduction equipment may be
added to the Flame Reactor to prepare wet or course
waste feeds to optimal feed characteristics. Also
scrubber technology can be added to the oxide product
collection system to handle hydrogen chloride gas
(HC1) and sulfur dioxide (SO2) emissions generated
during processing.
8. The HRD Flame Reactor process can meet
environmental permit requirements. The Flame Reactor
has met all permit regulations in commercial-scale
testing at HRD's facility in Monaca, Pennsylvania.
Commercial plant evaluations for a number of states,
including Pennsylvania, Texas, and California have met
with no permitting obstacles.
9. The HRD Flame Reactor process is amenable to
modular construction. Modular construction is a low-
cost option for permanent on-site construction at remote
locations. Because of the possibility of modular
33
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construction of the Flame Reactor, constructing a
transportable plant is also feasible.
10. The HRD Flame Reactor has very short start-up and
shutdown time. Most high-temperature operations
require long start-up and shutdown periods, sometimes
several days, in order to prevent temperature shock to
critical components. Because the Flame Reactor has no
refractory lining, the Flame Reactor can proceed froina
complete shutdown to waste processing in less than 15
minutes, and steady-state operations can be established
within 30 minutes after start-up.
As stated above, the Flame Reactor can operate at
temperatures in excess of 1,800°C, and burner flame
temperatures of 2,700*C have been detected. The Flanie
Reactor burner can generate 25 to 30 million Btu per hour of
energy and can produce over 200 cubic feet per minute of
CO. For these reasons, the following precautions are
employed to insure safe operation:
• Automatic shutdown if flame is extinguished
* Automatic shutdown due to high cooling-water
temperature
• Automatic shutdown with loss of cooling-water
pressure
• Automatic shutdown with loss of electrical power
• Automatic shutdown with loss of control air
• Nitrogen purge of the reactor
• Nitrogen purge in the baghouse
In addition, infrequent reactor water leaks do not result in
steam explosions. The dynamics of the Flame Reactor are
such that water entering the reactor is not trapped, but
remains on the surface of the molten slag where it boils off.
B.3 Secondary Lead Smelter Soda Slag
Test Program Summary
A summary of all of the Flame Reactor process test results
on secondary lead smelter (SLS) soda slag is provided
below. Additional information can be found in other sections
of this report and in the Technical Evaluation Report for this
Superfund Innovative Technology Evaluation (SITE)
Demonstration.
Seventy-two tons of SLS slag, a residue from the National
Smelting and Refining (NSR) soda slag lead battery
recycling process, was obtained from a stockpile of
approximately 350 tons in Atlanta, Georgia. The SLS slag
was generated at a plant in Pedricktown, New Jersey, where
a stockpile of 5,000 to 15,000 tons of SLS slag is located.
Both the Atlanta and Pedricktown locations are Superfund
sites. '
When received, the SLS slag averaged about 9.7 percent
moisture and was very coarse, as indicated by the particle
size distribution (PSD) shown in Table B-l. Chunks of
material larger than about 4 inches, some with diameters of
over 2 feet, were excluded from the sample used for the
Table B-1. Particle Size Distribution of SLS Slag as Received
Mesh Size
Percent Passing
JZInch
1.5 inch
1 lnch.w^
0.625 inch
0.25 fnch
0.111 inch
64.8 „
59.1
54.0
48.3
39.2
32.0
data in Table B-l. Prior to Flame Reactor processing, the
SLS slag was dried to between 2 and 7 percent moisture, and
it was crushed in a hammermill to less than 3/16 inch
diameter. Roughly 65 tons of dried and crushed waste feed
were prepared from the initial 72 tons. The prepared
material is characterized in Table B-2. The testing was
performed in three phases: (1) a series of shakedown runs to
determine the operating conditions for the demonstration
test, (2) the EPA SITE demonstration test runs, and (3) a
series of runs that added flux to the waste feed. These phases
are summarized below, and each is reviewed in full or in part
in other sections of this document and in the Technical
Evaluation Report prepared for the HRD SITE
Demonstration.
Table B-2. Characterization of Prepared Waste Feed
Analyte
Percent Weight
Lead,-dry basis „ *
Iron - dry basis
Sodium - dry basis
Silica - dry basis
Moisture (weightless at 110*0)
Passing 60 mesh
Passing 100 mesh
Passing 200 mesh
Passing 325 mesh '
7.01
11.0
10.7 '
2.63
5.2
50.9
36.4
22.9
15.2
X-ray diffraction indicated that the principal lead, iron, and
sodium compounds were caracolite [Na3Pb2(SO4)3Cl],
hydrous iron oxides, and sodium sulfate, respectively.
Metallic iron, metallic lead, and carbon particles were also
present as artifacts of the SLS slag process. Throughout the
tests, the prepared SLS slag handled well in the Flame
Reactor feed system.
B.3.1 Shakedown Runs
In a series of shakedown runs, 19.5 tons (roughly 30
percent) of the waste feed were treated over the range of
process operating conditions summarized in Table B-3. The
34
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Table B-3. Operating Parameters for Shakedown Runs
Table B-5. TCLP Results from Shakedown Runs (milligrams per
liter)
Parameter
Feedrate, tons per hour
Natural gas, mcf per ton
Oxygen, 1 00 scf per ton
Combustion air, percent oxygen
Range
."• 0.77 - 1.44
14.9 - 26.3
'230 -418"'"
59.7 - 85.1
Notes:
mcf = thousand cubic feet
scf = standard cubic feet
main objective of the shakedown runs was to identify the
optimal operating conditions for the demonstration test; the
tests also evaluated the response of Flame Reactor
parameters to the material.
A summary of the results of the shakedown runs, including
chemical analyses of the effluent slag and oxide product, is
presented in Table B-4. TCLP results for several effluent
slag samples appear in Table B-5 along with corresponding
lead analyses.
Table B-4. Results of Shakedown Runs (Weight Percent)
Analyte
Concentration Range
Effluent Slag
Lead *' ^
Iron
. Sodium ",: ,,
Silicon
Ss;SiuJfur >r X -
"" ^ / 0.096-3.08 , ,n
22.7 - 32.7
-, - ',' "-' ' 12.0,-14.'8 ,»,„„, -4:-
5.93 - 8.88
V> ''- i- "' Cv 1.7-6.0, '" ,;"
Oxide Product
Iron
xSodium-
Sulfur
15.3-23.9
2.62 - 4.81
9.08 - 15A
9.7-16.4
Lead recovery to the oxide was high for all of the runs, and
the Flame Reactor effluent slag was nonhazardous for a
wide range of lead concentrations. The PSD of the prepared
waste feed, though larger than recommended for Flame
Reactor processing, did not obstruct treatment. However,
unreacted particles of carbon and metallic iron were found
in a microscopic examination of the effluent slag.
For all of the runs, the effluent slag was tapped from the
separator and solidified on cooling into a solid mass on the
water-cooled conveyor, but within a few hours, the effluent
slag became friable and eventually broke down into a coarse
powder. This disintegration was caused by a hydration
reaction and occurred in all of the shakedown runs. The
Analyte
"Arsenic,
Barium
'Cadmium • "
Chromium
Sample 1
0.45
Sample 2
0.55, -
0.33
Samples
•: 3.3 ' *
<0.10
V£AA/ "O
<0.1
Mercury
x$efeniurn ...
J £ S ^ „
Silver
"Lead in Slag,
<0.1 0.1 <0.1
,v<0^5 „„, ;<0*25 t v<0.25 -;'
<0.01 <0.1 <0.1
'''0.20~ :;t:;-
-------
1
Tabta B-6. Average Composition of Solids as Analyzed by HRD and EPA (percent)
Waste Feed Effluent Slag
Analyta
; Aluminum
Antimony
Arsenic
Barium
} Beryllium
Cadmium
: Calcium
Carbon
eWorld®
Chromium
Copper
Fluoride
Iroo
Lead
; Magnesium
Manganese
Mercury
Potassium
Selenium
Silicon
Silver
Sodium
Sulfur
Thallium
Zinc
Notes:
l> A sine
EPA
0.60
0.037
0.52
0.086
0.0001
0.041
0.65
15.0
2.46
0.0088
0.19
0.013
10.3
5.41
0.23
0.075
0.00007
0.24
0.0073
0.28
0.0003
12.2
5.25
0.025
0.28
0.42
Not applicable
I!A offlimnt slan nssav nf !
HRD
0.69
NAa
"NA
NA
NA
0.043
0.72 - "<
14.7
2,64
0.024
0/17"
0.031
10.8
6.10
0.26
0.074
NA
0.23
NA
8.10
NA
12.2
8.4
NA
"NA"
0.44
9.77 nnroont load vif
EPA
0.036
; ; 0.026;;;;
j 0.16
0.0001 •
' 0.0004
, ,.1.30 ,
NA
NA
0.0089
0.34
NA
;' ,,,;2o.5
0.55
0.54
' 0.18
0.00001
0.24
0,0034
0.33
°* T.OJD004
15.5
, '"< < » NA
0.069
- . 0.080 ,,
"} CU6"
is excluded from this
HRD
NA
NA
<0.001
1.57"
•» V.JV-
1.09
0.040
, ' ' ;,. 0.37
0.016
- 22.7
1.12b
<( s«"^0".63
0.18
,NA
0.27
NA
10.2
15.3
NA
0.12
5 avnrnnn since i
Oxide Product
E-PA
. 0.062
0.12
0.028
7 6.0001
0.14
' ""' 0.23
NA
" NA
0.031
i, - ,0.17 *-*•
NA
, -/T CMS" <
18.0
,.J 0.035
0.028
" v ' 0.00001
0.74
^- , 0,0066
0.11
^ 0,0027
16.8
-» NA"
0.0071
f " 0.6'9,
1.62
t is inconsistent with a
HRD
, 0.080
NA
NA \
NA
NA -•-
0.15
„ 0.21
~f 2,95 _ _, .
0.034
. ,*, , 0.19 ,A ,
0.033
4,12
19.1
0,045
0.32
NA' 'f
0.74
NA
10.5
NA
15.6
14.7
NA
2.19
II other effluent
slag analyses. The aberration is attributed to lack of homogeneity of the waste feed and the small sample size (several grams)
sent to HRD. Inclusion of the assay raises the average to 1.60 percent lead.
Partitioning of the major elements into effluent slag and
oxide product was calculated using a statistically based
material balance program loaded on a personal computer. By
evaluating the interrelation of the data and the quality of the
data points, the material balance program calculates an
internally consistent balance of the process streams and their
components. Table B-7 presents the percent recoveries of
selected elements in the oxide, which were determined using
this material balance calculation. ;
The demonstration tests proved that the Flame Reactor can
consistently treat SLS slag to produce a recyclable metal
oxide product and a nonhazardous effluent slag. The
Table B-7. Oxide Product Recoveiy Rates for The
Demonstration Test (percent)
Analyte
Percent Recovery
Sodium
.Sulfur ' '-?$
Iron
Silicon'-' '<•
34
40,
36
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Table B-8. Average TCLP Results for Demonstration Test
(milligrams per liter)
Analyte Concentration
.Arsenic,,,,, _ - '":
Barium
*'Cadrnium,,r J"'\,L, '" '•' '"
Chromium
Lead' ;,, '"" v, """ ';-; \-
Mercury
- Selenium -? -- ,)», ; "v;
Silver
, 0,474 - "•'*:
0.175
""; ^ ,','*,'
Sodium
JSiHcjpn " '- -;^^:
Oxide Product
Lead ?- ,
•&>,>,
Iron
^Sodfcjm
Silicon
0.37-3.49 0.51-1.92
•' 18.3-25,7'' , „-;,-- -14.2 -20.:6''' '
14.1-21.2 10.9-12.9
16.Q,-20;8' 15.5-20.3 ;
3.60-5.51 2.93-4.91
14.0-1"6.1 " \'ff "'9.17^14^1 '"^
3.48-21.2 2.23-21.2
v 12.9-15.5 :"-, " " 9.15 -"11.3
B.3.3 Flux Additions
Silica flour flux (ground silica sand) was added to the waste
feed to improve the physical characteristics of the effluent
slag without diminishing the Flame Reactor's ability to
detoxify the hazardous waste. The effluent slag from
unfluxed processing, because it disintegrates when exposed
to moisture, has no reuse value and must be disposed in a
nonhazardous landfill. By adding flux to make a stronger
slag, the effluent slag may be marketed in one or more
aggregate applications, thereby reducing or eliminating the
costs associated with disposal. This would also create zero
waste from Flame Reactor treatment of SLS slag, because
both the oxide product and the effluent slag can be recycled
or reused.
The SLS slag was fluxed at levels of 12.5 percent and 25
percent. The fluxing rate is calculated by 100 percent times
the ratio of flux to waste feed. A summary of the operating
conditions for these runs appears in Table B-9, and the
ranges of chemical analyses for the major slag constituents
are presented in Table B-10.
At the 25 percent fluxing rate, the effluent slag did not
disintegrate even when submerged in water. Somewhat
glassy in appearance, this material might be used for such
Table B-9. Operating Parameters Silica Flux Addition Runs
applications as a road base, an anti-skid material, or asphalt
At the 12.5 percent fluxing rate, the effluent slag
disintegrated.
Table B-ll contains TCLP results for selected samples of
effluent slag from the 12.5 percent and 25 percent flux rate
runs. Table B-12 lists the percent recoveries of the principal
Table B-11. TCLP Results For Silica Flux Addition Runs
(milligrams per liter)
Analyte
12.5 percent silica
25 percent silica
„ Arsenic^
Barium
"'Cadmium „
Chromium
Lead
Mercury
'Selenium"
Silver
. <0*13 ^
0.41
-' *r!-
40-50 42-51
'-, \46-fer* !^,' «>?,<_ '(^,^.44^
11-17 12-17
*'? ' &A. - ^^
The higher fraction of silicon in the oxide is a result of
carry-over of the fine silica flour to the baghouse.
37
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elements in the products. The recoveries are based on the
combined mass flow of the waste feed and flux and were
calculated using a statistically based material balance
program loaded on a personal computer. •
TCLP results are consistent with the unfluxed SLS slag data
and demonstrate that the Flame Reactor's ability to
detoxicify the SLS slag was not impaired by the addition of
silica flux. With the exception of silicon, the recoveries
presented in Table B-12 are also in agreement with ithe
unfluxed processing of SLS slag. The higher fraction of
silicon in the oxide is a result of carry-over of the fine silica
flour to the baghouse. This could be reduced by using a
coarser silica as a fluxing agent.
i
B.4 Commercial Processing of \
Secondary Lead Smelter Slag
A preliminary operating cost estimate has been developed
to process the remaining SLS slag stockpile located in
Pedricktown, New Jersey, at the Monaca Flame Reactor
facility. The estimate is based on the results of the SLS slag
tests and the following assumptions:
• Processing would be performed at the Monaca Flame
Reactor facility.
• Excavation, loading, and transportation costs to Monaca
are not included. ,
• The SLS slag will be crushed to a PSD of 80 percent by
weight less than 200 mesh and will be dried to less than
2 percent free moisture.
• A 25 percent addition of silica flux will be used to
improve effluent slag integrity.
• The SLS slag will be fed at 2.7 tons per hour (tph) or
about 3.4 tph with flux.
• The costs are presented on a $ per ton basis for
processing 12,000 tons of material.
• Off-gas scrubbing for HC1 or SC>2 is not required.
The estimated operating costs are summarized below in
Table B-13. Pretreatment labor and utility costs are included
with the Flame Reactor cost. Overall staffing, including
supervision, will require twelve people. The pretreatment
ckcuit may be run by a single operator two shifts per day, 5
days per week. The Flame Reactor will operate 24 hours
per day, 7 days per week. Two Flame Reactor operators will
be required for each of the four shifts, with one daylight
mechanic and one supervisor.
Start-up and shutdown of the Flame Reactor and feed
preparation circuit will require an estimated 3 days. A
mechanic and supervisor will be required, bringing the total
to 30 man-days.
Capital cost assume financing at 12 percent interest over 10
years. The effluent slag is assumed to be marketed at a
value equivalent to handling and shipping costs for no net
profit or loss.
Tablo B-13. Processing Fee for Flame Reactor Processing of SLS Slag
Cost Factors
Units
$/UnIt
Units/ton
Cost/ton
Natural Gas
Oxygen
Labor
Electricity
Flux
Materials and Supplies
Direct Costs (subtotal)
Indirect Costs
Capital and Taxes
Subtotal
Oxide Product Shipping
and Recycling
Effluent Slag Handling
and Marketing
NET PROCESSING FEE
mcf
100scf
Manhours
kilowatthpur
tons
. 3.50'
0.25
0.05
36.00
8.62
/}#*
189.3
*"U1
'',
305.0
Q.25
30,15
47.31
'28.i6«
15.25
9.00
V / / /
17.28
147.15
10.00
58.06'
215.21
0.00^
0.00
$215.21
38
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References
3. F. Pusateri and others, 1987, Method for the Treatment of
Finely Divided Materials, U.S. Patent 4,654,077 (March
31)
J. F. Pusateri and others, 1988, Apparatus for the
Pyrometallurgical Treatment of Finely Divided
Materials, U.S. Patent 4,732,368 (March 22).
C. O. Bounds and J. F. Pusateri, 1989, Lead Blast Furnace
Slag Fuming via the FLAME REACTOR Process, 28th
Annual CIM Conference of Metallurgists, Halifax,
Nova Scotia (August).
C. O. Bounds and J. F. Pusateri, 1990, EAF Dust Processing
in the Gas-Fired FLAME REACTOR Process, Lead-
Zinc-Tin 1990 - World Symposium, Anaheim,
California (February).
J. A. Morgan, 1990, Personal Computer Program for
Optimized Material Balances.
39
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-------
Appendix C
HRD Flame Reactor Site Demonstration Test Results
41
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Appendix C
HRD Flame Reactor Site Demonstration Test Results
This Appendix presents a summary of the Horsehead
Resource Development Company (HRD) Flame Reactor
SITE demonstration. A detailed presentation of the SITE
demonstration results can be found in the Technical
Evaluation Report. The SITE demonstration was conducted
at HRD's research facility in Monaca, Pennsylvania, 35
miles northwest of Pittsburgh, using secondary lead smelter
(SLS) soda slag waste feed from the National Smelting and
Refining (NSR) site in Atlanta, Georgia. The waste was
transported to HRD, pretreated, and processed. The
residuals resulting from processing included a
nonhazardous effluent slag and a metal oxide product
C. 1 The NSR Site
The waste treated during the HRD SITE demonstration was
transported to HRD from the NSR site. The NSR site is
located at 430 Bishop Street in the northwest portion of
Atlanta, Georgia, in an industrialized area that is intermixed
with residential communities. Approximately 1 acre of the
4-acre site is owned by the Southern Railroad Company
(which is owned by Norfolk Southern Corporation), and the
remaining 3 acres are owned by Atlanta Forge and Foundry
Company. The waste treated is located on the property
belonging to Atlanta Forge and Foundry Company (NL
Industries, 1989 and 1990).
The facility has been operated by various owners for
approximately 80 years. During a portion of this time, lead
smelting and refining activities were performed at the site.
The most recent operations at the facility involved the
recovery of lead from storage batteries and other lead-;
bearing scrap and secondary lead smelting activities. NSR
purchased the facility from NL Industries on June 30,1981 j
and operated the facility until March 1984, at which time
NSR filed for bankruptcy. Since 1984, the facility has been
inactive (U.S. EPA, 1989; NL Industries, 1990).
During the 3 years that NSR operated the facility,
approximately 350 tons of processed rotary-kiln SLS slag
from the NL Industries' Superfund site in Pedricktown, NeW
Jersey, were shipped to the NSR facility in Atlanta for
possible recycling. This waste material was stored in two
bunkers at the NSR site. Seventy-two tons of this material
were collected, loaded in bulk storage bags in closed trailers,
and manifested for shipment to the HRD facility for
treatment during the demonstration. :
C.2 The HRD Facility
The HRD Flame Reactor pilot plant is located near Monaca,
Pennsylvania, and is operated by HRD, a division of
Horsehead Industries, Inc. The HRD Flame Reactor plant
and associated facilities occupy about 3 acres on a 5-acre
site. The plant and facilities include the main building that
houses the reactor; an auxiliary storage building; liquid
oxygen (©2) and nitrogen (N2) storage facilities; an oxide
product collection system with a bag-house oxide collector;
a cooling tower for the closed-loop, noncontact cooling
water system; and a pretreatment facility containing a waste
feed dryer and a hammermill. The facility is presently
operating under authority of an EPA RD&D permit (U.S.
EPA I.D. No. PAD 98 111 0570) and a Pennsylvania
Department of Environmental Resources (PaDER)
hazardous waste storage and treatment permit for research
testing of electric arc furnace (EAF) dust (RCRA code K061
hazardous waste), and certain characteristic wastes. These
operating permits have allowed extensive testing of the HRD
Flame Reactor.
The main HRD Flame Reactor building, measuring 40 by 80
feet and 60 feet high, presently contains the feed handling
and storage equipment, the reactor and slag separator, the
effluent slag cooling and conveying table, the control room
connected to a computer in the main office building, and the
motor control center. It also includes maintenance and spare
parts storage. The cooling tower, baghouse, and liquid O2
storage are located in the area outside the main reactor
building. Adjacent to the Flame Reactor building is an
office building housing administrative and engineering
offices and the computer center.
C.3 Description of Operations
After arriving at the demonstration site at the HRD facility,
SLS slag waste was stored in bulk storage bags in a covered
storage facility adjacent to the HRD Flame Reactor building.
The SLS slag was dried and crushed by feed preparation
equipment, located in a separate building. The feed
preparation equipment is designed to dry and crush the SLS
slag with a dryer and a hammermill. Once the SLS slag was
crushed and dried to the necessary specifications (see
Section 3 of this report), it was then loaded into portable
bins and transported to the storage facility prior to
processing, as waste feed, in the HRD Flame Reactor.
42
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Startup testing of the demonstration equipment began after
the feed preparation equipment had processed a sufficient
quantity of SLS slag to produce 5 to 10 tons of dry, crushed
waste feed. Prior to initial system startup, EPA and the
SITE team contractor reviewed the Demonstration Plan for
the HRD Flame Reactor (U.S. EPA, 1990) with HRD
personnel. During startup, the HRD Flame Reactor system
was checked for any problems that would prevent smooth
operation of the equipment. No problems were identified.
The next phase was the shakedown period. A
thermochemical process model was used to calculate
operating set points for feed rate, reactor temperature, O2
combustion air content, and other operating parameters.
The set points were then adjusted during the shakedown
runs by monitoring reactor conditions and evaluating the
condition of the effluent slag generated. The production of a
free-flowing, low-lead effluent slag indicated that the proper
values for the set points had been attained. The actual
demonstration was performed with the values set during the
shakedown runs.
The SITE demonstration took place the week of March 17,
1991, approximately 4 weeks after the startup procedures
and shakedown were completed. The initial run was a
background or blank run to establish a process baseline.
During the blank run, only natural gas was fired in the
reactor; no waste feed was admitted to the system. Stack
gas emissions were monitored and gas samples were
collected during the blank run.
Waste feed processing began after blank testing was
completed. During the waste feed runs, samples were
collected at various process points. These samples included
waste feed, oxide product, effluent slag, and stack gas
emissions. The number of samples collected at each
location, the frequency, and the rationale for sampling and
analysis parameters are discussed in Section 3.4 of the
Demonstration Plan for the HRD Flame Reactor (U.S. EPA,
1990), as well as in the Technology Evaluation Report for
this technology (U.S. EPA, 1992). Samples of the waste
feed, oxide product, and effluent slag were taken every 15
minutes. Six hourly composites, consisting of four
subsamples each, were collected during each run for the
waste feed and effluent slag. One daily composite of all the
subsamples of the oxide product was collected for each run.
Stack gas emissions were continuously monitored during the
entire run, and stack samples were collected for 2-1/2 hours
during the middle of each test run.
Four waste feed test runs (Runs 1, 2, 3, and 4) were
conducted during this phase of the demonstration on 4
consecutive days. The first run was discarded due to
fluctuations in the stack gas temperature, pressure, and flow
rate.
C.4 Analytical Results and Discussion
This section discusses the analytical results of the HRD
SITE demonstration. First, the results of the Toxicity
Characteristic Leaching Procedure (TCLP) tests are
discussed to determine if a nonhazardous effluent slag was
produced. Second, the constituent analysis results are
presented. The main purpose of the constituent analysis
data is to determine if the technology produced a recyclable
metal oxide product enriched in lead. Mass balance during
the treatment process, including factors affecting weight
reduction and percent recovery are also discussed. In
addition, constituent analysis data is used to characterize
the waste feed stream, and the results of stack monitoring
and emission sampling will be discussed. A complete
presentation of the analytical results is presented in the HRD
Technology Evaluation Report (U.S. EPA, 1992).
C.4.1 TCLP Results
TCLP tests were performed on the waste feed and on the
effluent slag. Table C-l presents the mean values, ranges,
and standard deviations of the results as well as the
appropriate RCRA regulatory criteria. As expected, the
waste feed was a RCRA characteristic waste because of
cadmium (D006) and lead (D008) concentrations. TCLP
testing determined that the effluent slag was not a
characteristic waste. In fact, the levels of cadmium,
chromium, and lead were all reduced to values below their
respective laboratory detection limits, and the level of
selenium was reduced by half. The levels of arsenic and
barium both increased, though they are still well below the
RCRA regulatory limit.
C.4.2 Constituent Analysis
Constituent analysis was performed on the waste feed,
oxide product, and effluent slag in order to determine if the
technology produced a recyclable oxide product enriched in
lead and an effluent slag product with lowered lead
concentration.
Two analytical digestion methods for metals were used. The
preferred digestion method was EPA Method 3050, because
it is a validated method with a standard operating procedure
that can be followed by any laboratory. The other method
was the method HRD uses, which is a mineral acid
procedure with microwave heating. All constituent analysis
results reported below are mean values obtained by using a
slightly modified EPA Method 3050 digestion procedure
which used a reduced sample size, unless otherwise noted.
The waste feed and the effluent slag matrices are both
difficult to digest and nonhomogeneous. The modified EPA
Method 3050 digestion procedure produces low
concentrations for silicon and chromium (less that 20
percent of the results of the HRD digestion procedure). The
silicon and chromium analyses were not considered to be of
major concern in this demonstration. Therefore, in
discussions below but not in the data tables, HRD silicon
and chromium data is reported. The HRD method is not
validated by EPA. The lack of homogeneity of the matrix
was demonstrated by poor duplicate results and by the large
standard deviations relative to each mean. A complete
tabulation of HRD SITE demonstration results is presented
43
-------
Tablo C-f. TCLP Results for the Waste Feed and Effluent Slag (mg/l)
Effluent Slag
Extract Concentration
Mean"
Range
Standard Deviation
In calculations.
NA = Not applicable
mg/L « milligrams per liter
RCRA Limit
Waste Feed
Arsenic
Barium
Cadmium
Chromium
Lead
Mercury
Selenium
Silver
0.213
0.0347
12.8
0.184
5.75
<0.010
0.0716
<0.050
<0.21 0-0.264
0.0177-0,0675' f.,f>.
7.61-15.8
0.140-0.283
4.35-6.80
^OfO**"*1 °
<0.030-0.160
„ ,
5.0
100.0
1.0
5.0
;><„, ''' Q£
1.0
.„" "> 5-° *"•• NA
NA
\l," 0-010
NA
5.0
100.0
'1'°' ,.. .
5.0
' , ,, ' ' 5.0
0.2
1.0 r
5.0
Notes:
*
Avprano nf 11
4 valnas: when an analvte was nre<
;ent below the detection lin
nit. the detection limit was
;used
in the HRD Technology Evaluation Report (U.S. EPA,
1992).
Tables C-2 and C-3 present the constituent analysis data for
the waste feed and the oxide product, respectively. The data
show clearly that volatile metals (lead, cadmium, and zinc)
are concentrated in the oxide product, while nonvolatile
metals (aluminum, calcium, iron) are concentrated in the
effluent slag. The oxide product contains some nonvolatile
species, because some effluent slag particles are entrained
with the off-gas stream.
Table C-4 presents constituent analysis data for the effluent
slag. The main constituents of the effluent slag are iron (20.4
percent), sodium (15.5 percent), calcium (1.30 percent), and
aluminum (1.53 percent). Silicon is reported by HRD to;be
present in the effluent slag at an average concentration: of
10.2 percent In general, the effluent slag is composed of the
oxides of nonvolatile metals such as iron, calcium, and
aluminum. Silicon and sodium appear in both the oxide
product and the effluent slag.
0.4.3 Mass Balance
A mass balance was performed on the HRD Flame Reactor
process using materials inventory data (total waste feed,
oxide product, and effluent slag) and the metals
concentration data for all three streams. Mass balance is an
accounting of where chemicals in the waste feed are
partitioned in the products after processing. Mass balance
closure is a determination of the amount of each chemical
present in the waste feed which can be accounted for in the
products. Stack emissions are not included because they are
small in relation to the other streams. For example, lead, the
largest stack emission, totaled 0.2 pounds compared to
approximately 2,000 pounds of lead in the oxide product for
the entire demonstration.
C.4.4 Weight Reduction
For all four test runs, a total of 47,300 pounds of waste feed
were processed, generating 11,200 pounds of oxide product
and 15,300 pounds of effluent slag. The total mass of oxide
product and effluent slag only account for 56.1 percent of
the waste feed mass. Therefore, the process has a net weight
44
-------
Table C-2. Waste Feed Analyses (weight percent)
Standard
Analyte Mean* Deviation Range
Aluminum £;; 0.596 ,^.,,jQ.0800_-,--v ,0.490^0.787^.-'
Antimony 0.0373 0.00503 0.0278-0.0455
•ATSGnfG "" ' "'' •> w»v5 • 5 '£$."* ' U»v * Oft , j ,U*v'n!»o*U" 1 iW
Barium 0.0861 0.00312 0.0804-0.0940
""Beryllium !*-"- >:6.06$70 ;'-" ao214;p.03o6""
Mercury 0.000013 0.000002 ^'oOOU0"
;^Potassiym '"'^ 0.707 T" , 0.0|48 '^, "0-630-'b.75i
'"'"" '* " '" nnnx'-ic.
Selenium 0.00520 0.00102 ri'nr^i;Q
u.uuooa
.s$iliCOnr ' 0-127 0-0102 v "0.^13-0/137
Silver 0.00269 0.000622 nnn^
0.00342
Sodfum <, 15".7 ^ 1.40 "^ ^13,7-16.8
Thallium 0.00746 0.000243 000773
TJn/ " ° 0.660 " 0,03>2 O'.612-0,687"'"
Zinc 1.38 0.272 1.00-1.62
The main reasons for the weight reduction were the
essentially complete conversion of carbon to carbon dioxide
(CO2) (15.0 percent), moisture to steam (3.35 percent), and
chloride to hydrogen chloride (HC1) gas (2.46 percent). In
addition, sulfur was partially converted to sulfur dioxide
(SO2) (2.26 percent). The remaining sulfur (2.99 percent)
was trapped in either the oxide product or the effluent slag.
These values are the average of data from Runs 2,3, and 4.
Notes:
a Average of three composite samples from Runs 2,3,
and 4; when an analyte was present below the
detection limit, the detection limit was used to
calculate the average.
b Due to matrix interferences, analytical results are
known to be lower than actual concentrations.
NA = Not applicable
45
-------
Tabla C-4. Effluent Slag Analyses (weight percent)
Analyte
Alumlmim
Antimony
Arsenic
Barium
Beryillum
Cadmium
Calcium
Chrom!umb
Copper
Iron
Lead
Magnesium
Manganese
Mercury
Potassium
Selenium
Siltconb
Silver
Sodium
Thallium
Tin
Zinc
Notes:
* Avnrann
Mean*
1.53
0.0357
0.0262
0.165
0.000101
0.000373
1.30
0.00890
0.344
20.4
0.552
6.543
0.175
<0.000010
0.238
0.00344
0.327
0.000394
15.5
0.0689
0.0796
0.113
( nf 1 ft hni trlu r ni
Standard
Deviation
0.138
0.0412
0.0291
0.0136
0.000008
0.000254
0.0973
0.00786
0.0324
1.60
0.252
0.0847
0.0268
NA
0.0194
0.00345
0.0979
0.000082
1.06
0.00862
0.0150
0.0287
mnncitoc civ j
Range
1.33-1.85
0.0100-0.190
0.00921-
0.134
0.139-0.183
<0.00087-
0,000110
s f V
<0.00023-
0.00135
1,ti&-1;45
0.00339-
0.0385
0^273-0.389
16.7-22.8
0.156-1.14*
0.441-0.761
0.132-0.231
<0.000010
0.199-0.269
<0.00226-
0.0176 ;
0.183-0.525
0.000250-
0.000510
IE8-16.8
0.0535-
0.0852
0;6544-6.il1
0.07109-
0.168
oanh frnm Rune '
NA:
2,3, and 4; when an analyte was present below the
detection limit, the detection limit was used to
calculate the average.
Due to matrix Interferences, analytical results are
known to bo lower than actual concentrations.
< Not applicable
C.4.5 Percent Recovery
Because no metals concentration data are available for Run
1, only data from Runs 2,3, and 4 were used. The materials
inventory data for these runs include: 32,600 pounds of
waste feed, 7,860 pounds of oxide product, and ll.QOO
pounds of effluent slag. Table C-5 presents oxide product
percent recovery data in two forms. The first form is the raw
percent recovery when the oxide product is compared to the
feed. Because mass balance closure is less than 100 percent,
due mainly to build up of material in the combustion
chamber and heat exchanger, the percent recoveries are low.
For lead, zinc, and cadmium, the percent recoveries are 77.7,
80.0, and 75.0, respectively. The second method presents a
normalized percent recovery. This method scales the
percent recovery data based on the mass balance closure, so
that the sum of the oxide product percent recovery and
effluent slag percent recovery is 100 percent. Using this
method, the percent recoveries of lead, zinc, and cadmium
are 95.8,89.7, and 99.6, respectively. EPA and HRD have no
fully satisfactory explanation for the relatively low
recoveries of arsenic, barium, or thallium in the oxide
product. These metals do not behave as one would expect
based solely on their boiling points. Arsenic is very volatile.
Barium and thallium are less volatile, having boiling points
similar to that of lead. The presence of metal species such
as oxides or chlorides may explain the anomalous
recoveries. The recoveries of these volatile metals warrant
further study, which is outside the scope of this report.
One objective of this SITE Demonstration was to form a
recyclable metal oxide product enriched in lead and zinc.
The Flame Reactor was successfully optimized by HRD to
do this. Arsenic and barium - and possibly thallium - have
negative economic impact on oxide product recycling and
were not desired in this product. Table C-6 presents the mass
of cadmium, lead, and zinc, as well as the other major
metals in the waste feed, oxide product, and effluent slag.
C.5 Feed Characterization
The analyses used to characterize the waste feed included
determination of particle size distribution (PSD), moisture
content, total carbon, energy content in British thermal units
(Btu), ash content, chloride concentration, fluoride
concentration, and sulfur concentration.
Analysis of PSD determined that 66.6 percent of the waste
feed was smaller than 200 mesh. The complete distribution
is shown in Table C-7. The standard deviation shows that the
PSD for all the runs was fairly consistent. HRD recommends
that 80 percent of the feed be less than 200 rnesh (0.0029
inches) for optimal recovery of volatile metals.
The SLS slag transported from the NSR site had a moisture
content of up to 30 percent. After pretreatment, the average
total moisture content was reduced to 3.35 percent. The
recommended moisture content is less than 5 percent total
moisture.
Both total carbon and total organic carbon analyses were
performed. These analyses produced results, within
analytical limits, indicating that all of the carbon is organic
carbon. The average total carbon content of the waste feed
was 15.0 percent. The carbon in the waste feed is consumed
as a fuel. The typical feed to the HRD Flame Reactor is low
in carbon, but carbon content is not a feed characteristic that
affects the recovery of volatile metals.
The average energy content of the waste feed was 1,665 Btu
per pound (Btu/lb). This can be attributed to the 15 percent
carbon present in the waste feed. A poor grade of
46
-------
Table C-5. Mass Balance Closure and Percent Recovery for Metals Present In the Waste Feed
Analyte
Aluminum ,-f, ,„
Calcium
'Copper ' "' , •-:
Iron
lead,,,,, __ , , ^
Magnesium
,|PotassiUm ' " ^ ^**" ' ?•?*
66.1
*i -, ^9'2 ~ "
Oxide Product
Percent Recovery"
----> '2.27-^'
7.48
7.53
8.50
" ' 69.8^
31.2
56.6
8o.o ,;;
Normalized Oxide
Product Percent Recovery1*
.«-* - %> , 2.56' '!',c
10.0
10.1
X" ---" 95.8 ,,;'; v, ,--
9.77
42.3
85.6
tl,, T' *89J'"" >*--
Notes:
The percent of the metal in the effluent slag is the mass balance closure minus the oxide product recovery.
The percent of the metal in the effluent slag is 1 00 minus the normalized oxide product percent recovery.
Concentrations of silicon from HRD's analytical procedure were used.
Table C-6. Major Metal Flow Rates (pounds of metal)
Major Metals8
Feed"
Slag"
Oxideb
Aluminum »
Antimony
, Arsenic
Barium
^Cadmium
Calcium
Copper- '
Iron
Lead
Magnesium
^Manganese
Potassium
Silicon^""
Sodium
Tin "";."" ~~^~ >~
Zinc
Notes:
a Mninr motnlc ar
194
12.1
\ 16.8
28.0
13.4
213
60.4
3350
1760
74.4
24'.5
79.6
89.8
3980
9f>
135
•A riftfinoi
>168
3.93
- "2.87" "
18.1
0.0409
143
. r 3?-^
2250
/'60.e
59.6
' 19.2
26.2
;; 35.8
1700
"" B'74
12.4
rl flQ hoinn nrA.QAi
- 4-42
9.84
8.67 *
2.22
10.0
15.9
*^ 12.6
253
"" 1370
2.57
2.08
55.6
10.'0
1230
>• ^t.'9
108
it in the
waste feed, oxide product, or effluent slag at a
concentration greater than o.1 percent.
It is thought that the mass balance closure is less
than 100 percent primarily because of build up of
material in the system.
bituminous coal has a heating value of 11,420 Btu/lb (Perry,
1985).
The waste feed was, on average, 81.6 percent ash. This is
not surprising given the fact that SLS slag is a residue from
a high-temperature process. The remaining 18.4 percent of
the SLS slag is almost entirely carbon (15.0 percent) and
free moisture (3.35 percent).
The waste feed was analyzed for three additional chemical
constituents: chloride, fluoride, and sulfur. The waste feed
averaged 2.46 percent chloride by weight, 0.0130 percent
fluoride by weight, and 5.25 percent sulfur by weight.
C.6 Stack Monitoring and Emissions
Sampling
During the HRD Flame Reactor SITE Demonstration, stack
gases were sampled for metals, HC1, and particulate
emissions, and were continuously monitored for SC>2,
nitrogen oxides (NOX), O2, CC>2, CO, and total
hydrocarbons (THC). The metals and particulate emissions
were determined using an EPA Modified Method 5,
isokinetic, multiple metals sampling train. HC1 emissions
were determined by a single point EPA Method 26
sampling train. The continuous emission monitors used the
following: EPA Method 6C for SO2, EPA Method 7E for
NOX, EPA Method 3A for O2 and CO2, EPA Method 10 for
CO, and EPA Method 25A for THC. All the standard EPA
methods can be found in 40 CFR 60, Appendix A, and the
multiple metals train is discussed in the Methods Manual for
Compliance with the Boiler and Industrial Furnace (BIF)
Regulations [40 CFR 266, Appendix IX].
47
-------
Tabla C-7. Partlcla Size Distribution of Waste Feed as Percent by Weight
Mesh Size
30
-------
(Ib/hr). This high emission rate could be expected because
the Flame Reactor had no acid gas control system, and the
waste feed contained, on average, 2.46 percent chloride by
weight. The BIF rule has promulgated risk-based emission
limits on HC1. The Tier II screening limit is 0.091 g/sec
(0.72 Ib/hr) [56 FR 7232]. The addition of a wet scrubber
should control HC1 emissions to below the applicable
standards.
C.6.3 Particulate Emissions
Because the HRD Flame Reactor process uses a baghouse to
capture the metal oxide product, paniculate emissions from
the Flame Reactor are low when the baghouse is maintained
and operated properly.
During analysis of the demonstration samples, problems
occurred with the gravimetric analysis, preventing accurate
determination of the paniculate emissions for all but the
blank run. Therefore, a worst case analysis of the test run
paniculate emissions was performed.
Particulate emissions are calculated from the sum of two
gravimetric analyses. The first analysis is conducted on the
filter. The EPA Method 5 sample train uses a filter that
exhibits 99.95 percent efficiency on 0.3-micron dioctyl
phthalate smoke. The filter is weighed before and after
sampling. The resulting difference is equal to the paniculate
weight on the filter. The blank run and Run 3 were the only
runs with positive differences. Negative numbers were
replaced with 1 mg for a worst case analysis. The second
gravimetric analysis is the acetone probe wash. The probe
(that part of the EPA Method 5 train that carries the gas
sample from the source to the filter) is rinsed with acetone to
remove any paniculate matter deposited on the probe. In the
laboratory, the acetone is completely evaporated, and the
residual is weighed. A laboratory error occurred, and thus
residuals were weighed only to +10 mg. The blank run and
Run 2 were the only runs without negative numbers. For a
worst case analysis, each run was assumed to show 10 mg of
dried acetone residual.
Even under a worst case scenario, the test run paniculate
emissions were lower than the paniculate emissions for the
blank run. The blank run paniculate emissions were slightly
higher than runs containing waste, because no oxide
product was formed to act as seed nuclei for particle
formation and growth. Therefore, the particles formed were
smaller and were not captured by the baghouse. The sources
of the blank run paniculate emissions may include residue
material in the system and lime used to condition the
baghouse bags.
The permit limit specified in the EPA RD&D permit for
paniculate emission is 0.02 grains per dry standard cubic
foot (dscf). As shown in Table C-9, all paniculate emissions
were below this standard. Table C-9 also presents the
paniculate emissions in Ib/hr and in grains/dscf corrected to
12 percent CO?, and 7 percent 02 for comparison purposes.
C.6.4 Continuous Emissions Monitoring Results
Emissions of SO2, NOX, O2, CO2, and THC were
continuously monitored for the blank run and for each 6-
hour test run. Table C-10 presents the average emission for
each run.
The HRD Flame Reactor currently has an air quality permit
issued by PaDER that limits SO2 emissions to less than 500
parts per million (ppm) for commercial operations. For the
SITE demonstration, for which the limit is not effective, the
SO2 emissions were below 500 ppm except for a 2-minute
period during Run 2. The maximum SO2 emission was 514
ppm, which occurred immediately following startup, after a
system shut down was required to cool the oxide product
collection systems.
Table C-9. Particulate Results
Grains/dscf Corrected to
Test Run
" Blanl^,
/ **
2
taV^
4
Notes:
mg/dscf
^ [I"" ,-0.517', ",""•_
, , , ,,',*'
0.191
'-iv,-^ •-'•:.. -0.294; "T,
0.213
Grains/dscf
'"' ,0:00797" ,
%f*' - „.. % ,
0.00295
', 6,00454 "^;
0.00328
12% CO2
„,' ' "'6.0282.';,',!,
,:-t <<
0.00887
;. 0.0114 -
0.00894
7% O2
, " " 0.0786
,' -,-tr ' '
0.0164
'-'f'0,0233'
•tA^fff' f f f ,
0.0168
Pounds/hour
;; - 0.522 - t:
&,, ' ~ - -
0.364
,^ "-I: ^ 0.548;^;^ ;
0.356
dscf = dry standard cubic feet
mg = milligrams
49
-------
Table C-10. Results of Continuous Emission Monitoring
Gas
Units
Blank Run
Test Run 2
Test Run 3
Test Run 4
SCv,
NO*
CO*
CO
THC
ppm dry
ppm dry
percent
percent
ppm dry
ppm dry as propane
z ^
173
19.6
3.39
4.17
1.64
268
16.0
--• <-> J 18.5 J
3.99
t*,..-' 'Mb'*
1.61
'«* ' „ t
15.81
' 18.3 *
4.77
""• 14,|* <
1.7
290
18.5
* 18.21
4.40
-\M •;
0.91
Notes: :
a The CO analyzer performed erratically during Test Run 3, therefore the CO data for that run are suspect.
ND = Not detected ,
ppm = parts per million
References
NL Industries, 1989, A Project Work Plan (Phase I, Tasks A,
B and D) for the National Smelting and Refining Site,
451 Bishop Street, Atlanta, Georgia (September 4).
NL Industries, 1990, Results of Task B - Subsurface
Investigation. I
Perry, 1985, Perry's Chemical Engineer's Handbook, 6th
Edition, McGraw-Hill Book Company, New York.:
U.S. EPA, 1989, Administrative Order on Consent. National
Smelting and Refining Site, Atlanta, Georgia, arid NL
Industries, Inc., Houston, Texas, EPA Docket No. 89-
26-C (June).
U.S. EPA, 1990. Demonstration Plan for the Horsehead
Resource Development Company Flame Reactor,
prepared by the PRC SITE Team for the EPA SITE
Program (November).
U.S. EPA, 1992, Technology Evaluation Report. SITE
Program Demonstration of the Horsehead Resource
Development Company Flame Reactor Technology, to
be published.
50
-------
Appendix D
HRD Flame Reactor Case Studies
51
-------
Appendix D
HRD Flame Reactor Case Studies
Note: This appendix to EPA's Applications Analysis Report
was prepared by Horsehead Resource Development
Company, Inc. (HRD). Claims and interpretations of results
in this Appendix are those made by the vendor and areinot
necessarily substantiated by test or cost data. Many of
HRD's claims regarding cost and performance can be
compared to the available data in Section 4 and Appendix C
of the Applications Analysis Report.
D.1
Case Study D-1
Material Processed: Steel industry electric arc furnace
(EAF)dust(K061)
Material Description: EAF dust is the emission control dust
generated from EAF carbon-steel production. The principal
components of interest in EAF dust are volatile metals such
as zinc, lead, and cadmium, which volatilize from mbtal
scrap during processing. The amount of galvanized scrap, a
feed component of EAF steel production, has increased in
recent years, increasing the concentration of volatile metals
in EAF dust. In EAF steel production, volatile metals land
other materials such as some alkali and halide components
are collected in the baghouse after cooling and condensing.
EAF dust also includes a significant amount of paniculate
carry-over consisting mainly of flux, slag, and iron oxides.
The table below summarizes the range of EAF dust
processed at the Monaca, Pennsylvania, Flame Reactor
facility. This range of EAF dust compositions is a good
representation of the range of composition found in; the
domestic steel industry.
Range of EAF Dust CK061) Compositions Tested at the
Monaca Flame Reactor Facility (percent) i
Cadmium 0.01 - 0.12
Calcium 1.3 - 30.8;
Chloride 0.26 - 5.o|
Chromium 0.1 - 4
Fluoride 0.07 -1A
Iron 15.0 - 44.4;
Lead 0.5 - 5
Silicon 0.43 - 2.5;
Zinc 5-401
EAF dust is a listed RCRA hazardous waste due to
leachable quantities of lead, cadmium, and chromium. Land
disposal restrictions and related regulations require that the
majority of EAF dust be recycled for zinc recovery and the
production of stable residues. The zinc units recovered are
valuable to the domestic zinc industry as feed, avoiding the
loss of natural resources.
Test Objectives: EAF dust processing was targeted as the
first commercial application for HRD Flame Reactor
technology, and several goals were established to achieve
this end. The primary objectives of this effort are
summarized below.
• The slag product must be nonhazardous according to
existing EPA standards and regulations.
• Metal oxide recovery economics must be maximized
within the constraints of producing a nonhazardous
slag.
• The design and operation of process equipment must be
optimized.
• The response of the HRD Flame Reactor technology to
variations in EAF dust composition must be evaluated.
• Process capital and operating costs must be determined
with enough confidence to estimate commercial costs.
Special Considerations: EAF dust is characteristically a
fine, dry material, suitable for HRD Flame Reactor
processing without feed preparation. However, dry EAF dust
(less than 1.0 percent moisture) is often cohesive or sticky,
which can cause bridging in storage vessels and can lead to
other solid transport and handling problems. HRD
engineered a materials storage and handling system
especially suited to EAF dust. Storage vessels have steeply
sloped sides and live-bottom feeders to discharge materials
in an effective, easily regulated manner with a first-in, first-
out inventory. Proper management of solid transport
throughout the system permits controlled metering to the
HRD Flame Reactor and efficient processing.
Process Tests: Since 1986, the Monaca HRD Flame Reactor
facility has processed over 2,200 tons of EAF dust over a
wide variety of process conditions. For both solid fuel- and
natural gas-fired operations, the following recoveries of
metal oxide products have been demonstrated over the full
range of EAF dust composition:
52
-------
• 92 percent zinc recovery
• 95 percent lead recovery
• 99 percent cadmium recovery
A series of tests were conducted in 1987 to generate data
for a petition designed to obtain a generic delisting of
Flame Reactor slag from EAF dust processing. A testing and
sampling plan was designed in conjunction with the EPA,
and 240 tons of EAF dust were processed. The EAF dust
was obtained from three different generators and contained
average to high concentrations of lead, cadmium, chromium,
and zinc. The results of these slag delisting tests clearly
prove the ability of the HRD Flame Reactor technology to
produce an inert slag from EAF dust processing. Results are
listed in Table D-l. Note that while the chromium is not
volatilized from slag, it is totally encapsulated in a fully
vitrified product, and no leaching occurs. (The leach tests
are from Extraction Procedure (EP) Toxicity testing,
because the work predates the establishment of Toxicity
Characteristic Leaching Procedure (TCLP) testing as the
standard leach test procedure.)
The HRD Flame Reactor has demonstrated that it is a viable,
commercial alternative for processing EAF dusts. It not
only recycles zinc, lead, and cadmium, but also produces a
delistable slag.
Process Economics: The HRD Flame Reactor technology is
easily scaled for regional or on-site EAF dust processing,
thereby minimizing transportation and handling costs.
Capital and operating costs for 20,000 tons per year (tpy)
coal- and natural gas-fired facilities are presented below.
Besides material costs and other items listed in Tables D-2
and D-3, the principal assumptions include the following:
• The cost of transporting EAF dust to the plant will be
borne by the generator.
• The product oxide requires additional processing at
some net cost so that recovered zinc, lead, and cadmium
can be converted into salable materials for recycling.
• The product slag will be marketed at a value sufficient
to cover transportation costs with no net profit or loss.
Slag market opportunities include cement clinker
production and traditional aggregate markets.
Table D-1. Slag Delisting Test Results for HRD Flame Reactor Processing of EAF Dust (mg/1)
Analyte
Lead &
Cadmium
•- ChroMum •
High Chromium
EAF Dust
<0.01
High Lead and
Cadmium EAF Dust
<0.029
<0.01
Typical
EAF Dust
/k <0.02
<0.01
'"">'> -/- "'
Subtotal
-"Engineering1 '• 'A' " °*
Contingency
,,,-X>;\, ' , $351,000,
340,000
v';'-,7^'- -,,,,,^,,",'313,000"
178,000
612,000
877,000
2,948,000
335,000
]' $351,000
472,000
178,000
- 448,000
612,000
848,000
Wjixm
4,010,000
405,000
TOTALtJAPITALCOST
53
-------
Table D-3. HRD Flame Reactor EAF Oust Processing Costs
Cost Factors
Natural Gas
Coal
Oxygen
Labor
Electricity
Materials and Supplies
Direct Costs (subtotal)
Indirect Costs
CapttaVTaxes /Royalty
Subtotal
Zinc Oxide Credits, at $0.50/lb Zinc
Gas Gas Coal Coal
Units $/Unit Units/Ton Cost/Ton Units/Ton Cost/Ton
mcf 2.50
ton 50
100 scf 0.22
man hours 16.00
kilowatt-hours 0.05
--: ;
'-•-
9.90 „ $34.65
0.379
125. " 31.25 , 114.
1.04 18.72 1.46
225. " 11.25 250.
14.25
: H°r12 *',,,
5.00
62.84 ""
177.96
- - (45.00)"
$ 18.95
28,50°
26.28
12,50
17.22
103.45
5.00
69.21
177.66
(45.00)"
NET OPERATING COST
$132.96
$132.66
Notes:
mcf = thousand cubic feet
scf = standard cubic feet
The operating costs for 20,000 tpy gas-fired and coal-fired
plants were presented in the Topical Technical Report for
the Gas Research Institute, Contract No. 5087-235-1601, in
May 1989. These costs appear in Table D-3. Plant staffing is
essentially independent of plant size up to about 33,000 tpy.
A natural gas-fired plant will require two operators per
shift, on a four shift per week basis, supported by a day-shift
mechanic and a supervisor. At 40,000 tpy, an additional
maintenance mechanic might be necessary. A coal-fired
plant would require an additional operator for every shift in
which the coal preparation equipment is operated.
Commercialization Status: On April 10, 1991, HRD
announced the signing of a long-term processing and site
agreement with North Star Steel Co. (NSS). Under the terms
of the 10-year agreement, HRD will construct and operate a
natural gas-fired HRD Flame Reactor facility to process
EAF dust at the NSS mini-mill operation in Beaumont,
Texas. The installation will be large enough to accept EAF
dust from other Southwestern EAF operations, offering cost
savings and improved customer service to other local iSteel
makers. Startup could be as early as the fourth quarter of
1992. HRD is also discussing opportunities for commercial
HRD Flame Reactor EAF dust processing with other
domestic and foreign steel makers.
D.2 Case Study D-2
Material Processed: Lead blast-furnace slag
Material Description; Lead blast-furnace slag is a residue
generated during primary lead smelting. Historically, the
slag has been stockpiled on land adjacent to the smelter
where it was generated. Lead blast-furnace slag typically
exceeds TCLP characteristic hazardous waste standards for
cadmium (D006) and lead (D008) but it is exempt from
hazardous waste classification by virtue of the 1980 Bevill
Amendment. Nonetheless, it is likely that stockpiling of lead
blast-furnace slag will be discontinued in the next few years.
Test Objectives: The primary technical objective was to
identify operating parameters that would simultaneously
produce a clean, nonhazardous slag while recovering enough
zinc and lead to produce a recyclable metal oxide product.
Sufficient information had to be gathered to develop
preliminary capital and operating costs.
Special Considerations: The blast-furnace slag had to be
dried and crushed prior to the HRD Flame Reactor process
tests. To maximize processing efficiency, the blast-furnace
slag was milled by a contract grinding firm to 70 percent by
weight finer than 200 mesh.
Process Tests: A total of over 250 tons of two distinctly
different lead blast-furnace slags was processed. We refer to
them as Slag A and Slag B. Representative analyses are
shown in Table D-4.
A small portion of a coarser, screened (not milled) fraction
of Slag A was run separately. The overall results allow for a
comparison of HRD Flame Reactor performance with
milled and screened portions of Slag A, and between Slag
A and Slag B, which were both milled. A summary of the
results is given in Table D-5, and EP Toxicity test results for
lead and cadmium appear in Table D-6.
Process Economics: The capital cost estimate for a HRD
Flame Reactor facility to process 100,000 tpy of dry, milled
lead blast furnace slag is presented in Table D-7.
54
-------
Table D-4. Lead Blast Furnace Slag Feed Stock Analyses
(percent)
Element
Slag A
SlagB
Cadmium ,v -
•• -. *s %
Calcium
C Carbon'"'- - H"
\ 1*$- , ^ •. '
Copper
•JrorT'.v?:; y" y*
Lead
,:,-«v^- "0.02
^ s "• -. ~ Vi i \ ~
7.8
->,-r ; gj,- , * -,«-
11 \ ,*,* ' ^ *
0.2
v'' ^:'">;26,7 y'-"
2.0
:' -0.02' ^V \
15.1
' """ -KJ ' "'''"''"
'$ l> *'*•' •.•.
0.3
,!l:"i5.8'7:^-
2.3
Sulfur
;zino-'
1.7
0.5
Assumptions include a typical 7-day, four-shift per week
operation; slag containing 10 percent zinc; and 30 percent
moisture from granulation or field storage. The capital
estimate also includes feed drying, milling, and coal
preparation equipment
The operating costs are shown in Table D-8. Labor
requirements are estimated at five operators and one
foreman per shift, plus three maintenance men and a
general foreman. Oxygen-enriched air would be available
from a pressure-swing absorption (PSA) unit installed on
site by a gas vendor. The miscellaneous category includes
nonprocess utilities, outside maintenance, repair parts, and
supplies.
Table D-5. Lead Blast Furnace Analytical Results (percent)
Zinc Recovery to, "'
Oxide , w „ >
Lead Recovery to
Oxide
ZiribfnSlag'
Lead in Slag
Zinc in Oxide '* >
Lead in Oxide
Slag A
Screened
" 40 -
80
' 5-87 /
0.44
?4i:e .
13.9
Slag A
Milled
85 '
95
J2.35*
0.18
r45,t.
10.3
SlagB
Milled
6$
87
5.06.
0.35
<• _
-
Table D-6. EP Toxicity Test Results for HRD Flame Reactor
Processing of EAF Dust (mg/l)
Analyte
Average EP
Toxicity Test
Analyses
Characteristic
Hazardous
Waste Limit
Cadmium
0.01
1.0
Note:
mg/L = milligrams per liter
Table D-7. HRD Flame Reactor Process - Capital Cost Estimate
for Processing 130,000 Tons per Year of Lead Blast Furnace
Slag With 10 Percent Zinc and 30 Percent Moisture
Major Area
Installed Cost
, Slag Loading, Transportation, and
'
Coal Preparation and Handling
>v*Ul|ifiej5 (oxygen arid air), V
Reactor, Product Slag Handling
«'$502,000 v
»-f* "'-
2,542,000
" ;423~,000 '
1,111^000
Environmental Controls
Subtotal '-'.---" ' ' ' % ^-*-' "'" '
Engineering
^.Contingency '--. ; ?'s"'~".
TOTAL PLANT COST
344,000
,,v- '&"; ' ,,;1°'693",°00 -
2,459,000
'-> *"''- „„,,, ~>.1,315;'000^
$14,467,000
Commercial Status: HRD is pursuing commercial
opportunities for Flame Reactor processing of lead blast-
furnace slag.
D.3 Case Study D-3
Material Processed: Neutral leach residue from electrolytic
zinc production
Material Description: In electrolytic zinc production, a crude
zinc oxide produced from calcining or roasting zinc
concentrates is leached with weak sulfuric acid to produce a
zinc sulfate solution. Zinc metal is subsequently extracted
from the zinc sulfate solution by electrolysis. The leaching
step is usually referred to as the neutral leach, because most
plants follow it with additional leaching steps using more
concentrated acid solutions.
The neutral leach residue is filtered from the zinc sulfate
liquor and undergoes limited washing. The raw residue
contains 25 to 40 percent moisture. The residue typically
contains 6 to 12 percent zinc (dry basis) as uncalcined zinc
sulfide and zinc ferrite, as well as zinc sulfate not removed
through washing. The residue also contains lead and
cadmium, and it often contains economically significant
quantities of precious metals.
Test Objectives: The objectives of the HRD Flame Reactor
process tests were 1) to maximize the recovery and value of
the metal components and 2) to produce a nonhazardous
slag byproduct.
Special Considerations: Neutral leach residue must be dried
and pulverized prior to processing in the HRD Flame
Reactor. A wet scrubber is required to remove sulfur dioxide
from the off-gas.
Depending on the particular electrolytic zinc plant, neutral
leach residue is either sold as a byproduct for the metal it
contains or is releached under more aggressive conditions,
as mentioned above. In the first case, the byproduct value is
55
-------
Table D-8. HRD Flame Reactor Processing Costs
Cost Factors
Units
$/Un!t
Units/Ton
Cost/Ton
Coal
., . ., t. ..... ..,„ ,..., _ .,
Natural gas
ton
-' !
mcf
-"50,00
3.50
' - 0,30 - -
1.90
, '^ , $15.00
6.65
Oxygen - PSA Rente)
Labor
Electricity
man hours
Materials and Supplies
Direct Costs (subtotal)
kitowatthours
7 percent of
capital per year
18.00
aos
0.63
11.34
14.75'
10.13
Indirect Costs
Capital and Taxes
67.47
2.00
}/ s
57,10
Subtotal
Zinc Oxide Credits, at$0.50/Ib Zinc
126.57
(22.50)
NET PROCESSING FEE
$104.07
Notes:
mcf=thousand cubic feet
PSA = Pressure swing absorption unit
set at a heavily discounted rate, well below the full value of
the metals it contains. In the second case, nearly all of the
metals are extracted using hot, strong acid leaching.
However, unwanted species are also leached, most notably
iron, which must be removed from the zinc sulfate liquor.
Several techniques for iron precipitation are used for
purification, but all of the precipitates contain hazardous
levels of leachable heavy metals such as lead and cadmium.
Process Tests; Three separate test programs vjere
conducted, using neutral leach residue from two separate,
domestic electrolytic zinc plants. For each program, the raw
residue was dried and crushed by third parties. The use of
different vendors for the feed preparation allowed an
evaluation of the effect of feed particle size on propess
performance. Both solid fuel- and natural gas-fired process
testing were performed. I
I
The process testing results are summarized in the t'able
below. In addition, when the feed particle size distribution
(PSD) was reduced from 80 percent by weight finer than 350
microns to 80 percent less than 75 microns, zinc recovery
increased by an average of 10 percent for a given set of
operating conditions. Lead and silver recoveries |alsq
improved, but to a lesser extent.
Neutral Leach Residue Results
Metal Recoveries to Oxide
Lead 99 percent
Silver 90 percent
Zinc 90 percent
Slag TCLP Extraction Tests
Arsenic 0.29 mg/L
Barium 13.2 mg/L
Cadmium <0.02 mg/L
Chromium <0.1 mg/L
Lead <0.2 mg/L
Mercury <0.1 mg/L
Selenium <0.25 mg/L
Silver <0.01 mg/L
Note: mg/L = milligrams per liter
Process Economics: Capital cost and processing fee
breakdowns are shown in Table D-9 and Table D-10,
respectively. The capital costs are for a 20,000 tpy coal-
fired Flame Reactor on a brownfield site (an already
developed industrial site). The plant includes drying and
grinding equipment for the neutral leach residue, coal
grinding equipment, and a off-gas scrubber for sulfur
dioxide.
Energy consumption for drying and crushing is included in
the natural gas and electrical costs. Materials and supplies
costs are estimated at 7 percent of the capital cost per year.
Capital and taxes include financing the plant capital at 12
percent interest over 10 years. Zinc credits are based upon
90 percent recovery of zinc as oxide at 25 percent of the
stated zinc price.
Commercial Status: HRD is pursuing an opportunity for
commercial processing of neutral leach residue.
56
-------
Table D-9. HRD Flame Reactor Process - Capital Cost Estimate
for Processing 20,000 Tons per Year of Neutral Leach Residue
with 10 to 12 Percent Zinc and 30 Percent Moisture
Major Area
Installed Cost
Feed and Coal Storage
' Reactor,'^* SyslJm v, ,^
Product Slag Handling
v ,$ 1,58Q,000:<
250,000
\:\ ' -3SO,GQ£r
328,000
Electrical and Controls
752,000
TA
Subtotal
Enginee'rinij ;"
Contingency
4,428,000
667,000
D.4 Case Study D-4
Material Processed: Goethite iron precipitation residue
from electrolytic zinc plant purification circuits
Material Description: Goethite is an amorphous, hydrated,
iron precipitate formed during the purification of zinc sulfate
liquor. It is removed from the liquor by filtration, followed
by limited washing. Goethite contains 6 percent to 10
percent zinc as sulfate.
Test Objectives: Along with a significant amount of zinc,
goethite often contains hazardous levels of leachable
cadmium and sometimes lead. These HRD Flame Reactor
process tests were directed at 1) maximizing zinc recovery
and 2) rendering a nonhazardous slag byproduct.
Special Considerations: Goethite iron requires drying and
crushing prior to processing in the Flame Reactor.
Process Tests: Two test programs were performed.
Representative results are presented below.
Goethite Test Results
Metal Recoveries to Oxide
Lead 93 percent
Zinc 77 percent
Slag TCLP Extraction Tests
Arsenic <0.02 mg/L
Barium 0.13 mg/L
Cadmium <0.01 mg/L
Chromium <0.01 mg/L
Lead 0.1 mg/L
Mercury <0.001 mg/L
Selenium <0.03 mg/L
Silver <0.02 mg/L
Process Economics: A breakdown of the capital cost for a
50,000 tpy natural gas-fired Flame Reactor appears in Table
D-ll. The costs assume brownfield construction to take
advantage of existing infrastructure. The goethite iron is
Table D-10. HRD name Reactor Processing Costs for Neutral Leach Residue Processing
Cost Factors
Units
SAJnlt
Units/Ton
Cost/Ton
>iCoai ^ ,;>,\ '^ \ ;*,>«- \/ ^,,*y. /,! ^" '' '",^ ,',„ ton,_ - -,**,
Oxygen 100 scf
Natural 6as '" ' ,- V;' -- ':-- i-.,- '"mcf '"'"v •
; s sSl ^ <^, -' ^^-V / j j^v.^, fff '•'• ^
Labor man hours
^Electricity ;: - ,-x, ' , ^ "'V „ „ ^ >"^',,': /felbwatthours
Materials and Supplies
Direct Cdste (subtota)} v>a • -v,,,, , -vv_~ %-v" „ ^ ' vr;,,>v --^-^
Indirect Costs
> Capttafand Taxes >,-;' ~" 7™' -;< "'",'•? -""-v-"' ' "„, > - -;
\" ^ ' ^; *- ,-,••,,'•••• , <&* •,„,,„ ****^* , '"
Subtotal
Zinc,Oxide'Cre4ite)at$630^bZfnoj ' -^ "*:';'/ ' ' -
NET PROCESSING FEE
- ' 50,00,^" ~1, , -0.44 v> _ ^,, , , «. ,, , „ >, ,'$ 22,00' -
0.25 154. 38.50
, , ,.: ^ 3.50 , -; - "3,20, ,, ?#->,/_ /•- '^^ ' 1 i .20 v
18.00 1.46 26.28
°, -0.05 '"••'•" 389, Ss',,j, '" ' '19.45'-
21.70
;^; * . '"^ .^.'""-K-. -,-r - "^ - ,v;x ^Af9-i3
5.00
*x-'?'V\T\,..W"- ' ' ::, 85-49
229.62
• ,,„, ''^ -''**'' '--'V V, "": -x(36.oo}"
$183.82
Notes:
mcf = thousand cubic feet
scf = standard cubic feet
57
-------
Table D-11. HRD Ram* Reactor Process - Capital Cost
Estimate for Processing 50,000 Tons per Year of Iron Precipitate
(Gosthlta) with 12 Percent Zinc and 30 Percent Moisture
Bartlesville, Oklahoma. The plant would dry and crush the
goethite iron and would excavate and process stockpiled
material.
Major Area
Food Preparation and Storage
Reactor, Feed System
Stag Handling
Off-gas and Oxide Handling
Electrical and I lititfes
Buildings and Site Improvements
Subtotal
Engineering
Contingency
TOTAL PLANT COST
Installed Cost
$2,466000
523,000
447,000
1,399,000
1,750,000
397,000
6,982,000
700,000
768,000 "
$ 8,450,000
dried to a fine powder in a spray drier, and a wet scrubber is
used to strip sulfur dioxide from the tail-gas. ;
The cost components of the processing fee are shown in
Table D-12. Oxygen-enriched air will be supplies by a
leased PSA unit; energy consumption for the PSA unit is
included in the electrical costs. Materials and supplies costs
are estimated at 7 percent of the capital cost per year.
Capital and taxes include financing the plant capital at 12
percent interest over 10 years. Zinc credits are based upon
90 percent recovery of zinc in the oxide and 25 percent of
the stated zinc price. j
Commercial Status: HRD has made a proposal for a Flame
Reactor facility to process 50,000 tpy of goethite in
D.5 Case Study D-5
Material Processed: Brass foundry Wheelabrator dusts
Material Description: The material consists of brass
foundry sands collected from casting cleaning operations.
The metal content, mainly copper and copper alloy, is
usually around 5 to 10 percent by weight, but some of the
material collected for these tests contained up to 45 percent
metal by weight. The material often does not meet
characteristic hazardous waste criteria for lead (D008) or
cadmium (D006).
Test Objectives: Recover volatile metal components as a
mixed metal oxide product, recover nonhazardous slag
byproduct, and investigate the production of a copper alloy
product.
Special Consideration: Because of the high silicate content,
sand had to be added to the Wheelabrator dust as a fluxing
agent in order to obtain a fluid slag. Sand particles were
much coarser than typical HRD Flame Reactor feed, making
this process more difficult, because there is very little time to
melt large particles in the reactor. After trying several
fluxing agents, iron oxide was determined to yielded the best
slag properties. EAF dust was chosen as the iron-rich
fluxing agent.
Process Tests: As shown in the data table below, the Flame
Reactor product slag easily met EP toxicity criteria for a
nonhazardous waste. A molten copper alloy was readily
collected with the slag.
Table D-12. HRD Flame Reactor Processing Fees
Cost Factors
Units
$/Unlt
Units/Ton
Cost/Ton
Natural Gas
Oxygen - PSA Rental
Labor
Electricity
Materials and Supplies
Direct Costs (subtotal)
Indirect Cost
Capital and Taxes
Subtotal
Zinc Oxide Credits, at $0.50/lb Zinc
NET PROCESSING FEE
Notes:
met ' 3-50 16-80 '58-80"
19.20
man hours 18.00 0.79 ° ^ 14\22 '
kilowatthours 0.05 471 23.55
, - , « ' ' ' <*< <* , \ , 12,88
128.65
r ^ 3.00 y
63.85
"" "" '" 195,50 ;
1 (27.00)
- - - ' » « $168.50
mcf = thousand cubic feet
PSA « Pressure swing absorption unit
58
-------
Slag EP Toxicitv Leach Tests
Arsenic <0.01 mg/L
Barium . „ 0.05 mg/L
Cadmium <0.004 mg/L
Chromium <0.006 mg/L
Lead 0.13 mg/L
Mercury <0.002 mg/L
Selenium <0.01 mg/L
Silver <0.01 mg/L
Process Economics: The capital costs for a Flame Reactor
facility to process 12,000 tpy of brass foundry sand appear
in Table D-13. The scenario includes processing EAF dust at
a 1:1 ratio with foundry sand, as described above. Therefore,
the Flame Reactor capacity is 24,000 tpy of feed. Equipment
for excavating and drying the sand is included.
The processing fee breakdown in Table D-14 reflects only
the foundry sand processing fee. Energy costs for drying are
included. Materials and supplies costs are estimated at 7
percent of the capital cost per year. Capital expenses and
taxes include financing the plant capital at 12 percent
interest over 10 years. It is assumed that the foundry sand
contains 15 percent copper, and that 65 percent is recovered
as alloy, valued at 40 percent of the stated price of copper.
The foundry sand does not contain sufficient zinc for an
oxide credit.
Commercial Status: Foundry sand processing economics
are very sensitive to the availability of a low cost flux. HRD
has made a proposal for remediation of foundry sand
landfilled at a brass foundry site.
D.6 Case Study D-6
Material Processed: EAF dust spiked with CC14
Material Description: CC14 was fed into the Flame Reactor
simultaneously with steel mill EAF dust in order to
Table D-13. HFJD Flame Reactor Process - Capital Cost
Estimate for Processing 12,000 Tons per Year of Brass Foundry
Sand per Year Fluxed with EAF Dust
Major Area
Installed Cost
Feed Preparation and Storage :
Reactor, Feed System
Slag Handling "
Off-gas and Oxide Handling
Etecfrteal and 'Utilities " l> "
Buildings and Site Improvements
Subtotal ,~ f > Vv~ £ '
Engineering
, Contingency
$1,900,000'
350,000
370,000
550,000
1,050,000
470,000
> 4,690,000
940,000
470,000
TOTAL PUNT COST
$ 6,100,000
simulate a metal-bearing waste contaminated with
hazardous organic compounds.
Test Objectives: The purpose of this test was to demonstrate
the ability of the Flame Reactor process to destroy
hazardous organic contaminants in conjunction with the
treatment of metal-bearing wastes.
Special Considerations: The CC14 was injected separately
from the EAF dust to avoid fouling the pneumatic injection
system. The CC14 was introduced at the same point in the
process, but through a port offset from the solid feed by 90
degrees.
Process Tests: The CC14 was fed at a rate equivalent to 5
percent of the total feed. The average destruction removal
efficiency (DRE) was 99.9986 percent, and no CC14 was
detected in either the slag or oxide products. The test data
are summarized in the table below.
Test Results
EAF dust feed rate 24001b/hr
CC14 feed rate 126 Ib/hr
CC14 in total feed 5 percent
CC14DRE 99,9986 percent
CC14 in slag product < 800 ng/kg
CC14 in oxide product < 800 ng/kg
CC14 in off-gas 9.21x10-10 Ib/dscf
CC14 emission rate 1.01x10-3 Ib/hr
Notes:
ng/kg = nanograms per kilogram
Ib/hr = pounds per hour
Ib/dscf=pounds per dry standard cubic foot
This program demonstrated the ability of the Flame Reactor
technology to effectively destroy hazardous organic
contaminants in metal-bearing wastes.
Process Economics: The sampling, monitoring, and
analysis costs for organic chemicals will be higher than for
materials containing only toxic metals. The capital costs
should not be much higher than for similar materials without
organic chemicals. However, the costs of organic analyses
could significantly impact processing costs, depending on
the compounds involved.
Commercial Status: HRD is pursuing opportunities to apply
the Flame Reactor technology to treat metal-bearing wastes
contaminated with organic chemicals. Several wastes are
under review for process testing.
D.7 Case Study D-7
Material Processed: Secondary lead smelter (SLS) soda slag
fluxed with silica flour
Material Description: The material was obtained from the
same 72-ton lot of SLS slag processed in the SITE
demonstration test.
59
-------
Tabfa D-14. HRD Flam* Reactor Processing Fees
Cost Factors
Units
S/Unit
Units/Ton
Cost/Ton
Natural Gas
Oxygen
Labor
Electricity
Materials and Supplies
Direct Costs (subtotal)
rocf,
100 scf
(rrian hours
kilowatthours
3.50
0.25
18.00
0.05
8.39
113.4
1.21
310.
29.37
28.35
15.50
"17.79
112.79
Indirect Cost
Capital and Ta>:es
75.90
Subtotal
Copper Credits, at $1.00/lb Copper
' '"" 193,69
t^l^-rtf. j&>f#vt/tWt ' f.'tff.
(78.00)
NET PROCESSING FEE
Notes:
me! = thousand cubic feet
scf=standard cubic feet
Table D-15. Test Summary
0 % Silica
12.5% Silica
25 % Silica
Lead in Slag
Lead In Oxide
Load Recovered to Oxide
Slag TCLP, Lead
Slag TCLP, Arsente
1.12% •
19.1%
91%
<0.33* mg/L
0.474* mg/L
0.69% ,.
17.4%
,— -,'
. 95%
^ v>
0.20 mg/L
" °'69%
17.5%
, , •>
' ' 07%' "
^ v •*\4'i'}'$',%%
<0.20 mg/L
v<0.13mg/L
Notes:
" Chemical analyses done by Versar, Inc. on demonstration test samples; all other data are from aniilyses by HRD.
mg/L = milligrams per liter.
79 * J/Ofwwfil*
Test Objectives: The purpose of this test was to make a more
durable Flame Reactor product slag by adding silica flour
(ground sand) as a fluxing agent. No attempt was made to
optimize the flux addition in terms of composition, quantity,
or cost
Special Considerations: As in the SITE demonstration test,
SLS slag had to be dried and crushed prior to Flame
Reactor processing. Also, silica flour flux was blended with
the SLS slag during feed preparation so that the materials
would be well mixed before processing.
Process Tests: The SLS slag was fluxed with 12.5 ahd 25
percent silica flour. (The flux addition is calculated as
follows: [percent flux] = [100 percent] x [lb of flux] / [Ib of
SLS slag].) A summary of? the results is given in Table I)-15.
TCLP data show that adding silica flour to the SLS slag did
not reduce the Flame Reactor effectiveness in detoxifying
the material. In fact, in the case of arsenic, TCLP
performance was improved over the 0.474 mg/L average for
the unfluxed material in the SITE demonstration test.
Fluxing with 25 percent silica flour produced a firm, glassy
slag that does not disintegrate on contact with water. This
product slag should be suitable for distribution in aggregate
markets as bituminous sand for asphalt. The SLS slag
fluxed with 12.5 percent silica flour did not remain firm and
disintegrated on contact with water.
Process Economics: The operating costs for the commercial
scenario are presented in Appendix B (Vendor's Claims) of
this report and are repeated in Table D-16, with the
exception that the SLS slag is fluxed with 25 percent silica
60
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Table D-16. HRD Flame Reactor Processing Fees
Cost Factors
Natural <3a|- ,„., -'^ 'w '--'', ^ ^ -:/K"
Oxygen
Electricity
Flux , , ' ' "'^ x *-'--", '^,~_ <|T,,;L, ,
Materials and Supplies
'"Drrecf^b'stslsul total) % --- ^- '-;,_,; •'
Indirect Cost
Subtotal
"Produ^uxJcJe^ShippIng and Recycling 7;V ' ,
Product Slag Handling and Marketing
NET^PROTSiSSfNGTEe^ »' ':;; .-- s/
Units $A)nlt Units/Ton Cost/Ton
*" ~~ j •—,/, j j J v ' ' fffOF •• -K^'^' "w-<* ^ <3i"5l/ v -. o>b^ ^^ *"* " t 30. 1 5
j/> v- ',^. •• ^"V-T-. ' - - = ijy*% ,. ^*-<^^T"^^ ••'?*'< f , '•••''*&'' 'jj-^^w-^^*
100 SCf 0.25 189.3 47.31
r^v-*'' ">,nw9Jwu^, "*' ;;^; "v^^./r .T.I.*! ",c "" -x 'U- ^a?o:.
kilowatthours 0.05 305. 15.25
,,,„ -&>xr,, ' tow _ ->A,', '"->;- ---,55.00°^- ', ^0^25!' -\" 5%.;',' ' '13.75^,'
17.37
v>s%; -;'--:" "~ '— ^ ':^"'- , '^-' -,"'? v *AS 159-04 '
5.00
238.92
/%:-"-'"---•' , •*•:?*-- ""•""', ,;^ :^'~ ^ ;?v -,,,,_ -.19,00
0.00
„- ">?**''„'.*"*''• --^y-- """^A -;« >;- ' ->„-**--' - -$257.92,
Notes:
mcf = thousand cubic feet
scf = standard cubic feet
flour. Instead of disposal in a nonhazardous landfill, the sufficient to cover handling and transportation, resulting in
product slag is marketed as an aggregate at a value no net profit or loss.
61
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