United States
Environmental Protection
Agency
Air and Energy Engineering
Research Laboratory
Research Triangle Park NC 27711
Research and Development
EPA/600/S7-86/017 Dec. 1986
Project Summary
Evaluation of Conventional
and Advanced Coal Cleaning
Techniques
A. B. Onursal, J. Buroff, and J. Strauss
This report assesses the capability,
cost, and environmental effects of coal
cleaning to reduce sulfur dioxide (SO2)
emissions. It is the culmination of a 4-
year program directed by EPA's Air and
Energy Engineering Research Labora-
tory-
The report includes evaluations of
SO2 emission reductions by cleaning
coals on a state and regional basis; de-
scriptions of coal cleaning equipment;
calculation of environmental tradeoffs;
development of algorithms for coal
cleaning capital costs, operation and
maintenance costs, and cost-benefits;
brief descriptions of advanced coal
cleaning processes; summaries of coal
and utility industry trends relative to
coal cleaning; and development of a
utility-system-based model for calculat-
ing SO2 emission compliance costs
using coal cleaning, blending, and flue
gas desutfurization options.
The report notes that 85 percent of
the SO2 emission reductions produced
by coal cleaning would be attained
from coals in the Northern Appalachian
and Eastern Midwest regions. For a
given coal, the environmental tradeoff
is a reduction of 20 to 50 percent in po-
tential SO2 emissions and 25 to 85 per-
cent reduction in particulate loadings
versus a 50 to 150 percent increase in
solid wastes generation. The capital
cost of a cleaning plant is quite depen-
dent on the coal, the mining method,
and site specific factors. However, a lin-
ear relationship can be developed for
O&M costs versus cleaning plant feed
rate. Most benefits of cleaning were
quantified based on the results of a re-
cent study of the Tennessee Valley Au-
thority (TVA) system.
Several chemical and advanced phys-
ical coal cleaning processes continue to
look promising for production of very
low sulfur, low ash coals. Generally, the
number of coal preparation plants and
amount of coal cleaned can be expected
to grow substantially in the next 10
years. This growth rate will depend
largely on energy prices and EPA poli-
cies affecting SO2 emissions.
This Project Summary was devel-
oped by EPA's Air and Energy Engineer-
ing Research Laboratory, Research Tri-
angle Park, NC, to announce key
findings of the research project that is
fully documented in a separate report
of the same title (see Project Report or-
dering information at back).
Introduction
In the mid-1970s, EPA's Office of Re-
search and Development began a com-
prehensive program to determine the
sulfur removal capabilities of coal
preparation, a technology that has been
in commercial use for over 50 years.
This report is the culmination of that ef-
fort. It contains information concerning
the control of SO2 emissions from coal
burning sources using coal preparation.
Coal preparation—also referred to as
physical coal cleaning (PCC), coal wash-
ing, or coal beneficiation—is a series of
mechanical operations that remove
mineral matter (ash) from coal. Coal
preparation processes are designed to
provide ash removal, to enhance en-
ergy production, and to standardize the
coal product. Sulfur is removed be-
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cause the pyritic material that is re-
moved comprises sulfur and iron.
Preparation plants are not designed to
optimize sulfur removal. The utility in-
dustry uses cleaned coal in place of raw
coal to provide a higher energy content
fuel, to meet emission regulations, and
to improve boiler performance and
availability (less than one-third of utility
steam coal is cleaned). There are about
500 coal preparation plants in the U.S.,
almost all located at the mine site.
Conclusions
The conclusions drawn by this com-
prehensive study of coal cleaning tech-
nology are presented below.
• Washing reduces, by about 30 per-
cent, the heat-specific S02 emis-
sion parameter for the high sulfur
coal regions of Northern Ap-
palachian, Eastern Midwest, and
Western Midwest. The percent re-
duction in the heat specific S02
emission parameter for the low sul-
fur coal regions (i.e.. Southern Ap-
palachian, Alabama, and Western)
ranges from 13 to 22 percent.
• In the Northern Appalachian and
Eastern Midwest regions, coal
washing can double or triple the
amount of coal able to meet moder-
ate S02 emission values.
• Coal washing does not measurably
increase the amount of coal able to
meet the stringent 1.2 Ib S02/106
Btu* emission standard.
• Emission reductions by coal wash-
ing are sensitive to both energy or
Btu recovery and specific gravity of
separation. For example, a 5 per-
cent drop in energy recovery (from
95 to 90 percent), caused by allow-
ing more pyrite and coal to go to
the refuse stream, can produce a
cleaner product with a 20 percent
reduction in SO2 emissions from
the raw high sulfur coals. An addi-
tional 10 to 15 percent reduction in
potential SO2 emissions can be ob-
tained by allowing energy recovery
to fall to 80 percent for high sulfur
coals. Low sulfur coals show a 10
percent drop in S02 emissions as
energy recovery is reduced from 95
percent to 90 percent. The energy
recovery loss may be associated
with reducing the specific gravity of
separation. For example, lowering
the specific gravity of separation in
the preparation process from 1.6 to
1.4 will reduce high sulfur coal
emissions by 10 to 20 percent. Low-
ering the specific gravity may have
almost no effect on lowering S02
emissions from low sulfur coals.
• Current coal preparation equip-
ment is capable of removing only
some pyritic sulfur from coal; it is
ineffective for the removal of or-
ganic sulfur and most fine-grained
pyritic sulfur.
• Coal washing reduces S02 emis-
sions by 20 to 50 percent and de-
creases paniculate loadings in the
flue gas by 25 to 80 percent; it in-
creases solid wastes by 25 to 150
percent. The overall net effect of
washing is to partially transfer
waste generation from the point of
use (i.e., power plant) back to the
point of origin (i.e., coal mine and
preparation plant). For every ton of
S02 removed, from 1 to 20 tons of
solid waste may be generated.
• Cleaning costs are affected by level
of cleaning (i.e., as coal top sizes
decrease, both capital and operat-
ing costs increase), play yield (i.e.,
as yield decreases, cleaned coal
costs increase), and plant size (i.e.,
economy of scale is operative). Ac-
curate costing of cleaning plants
must be based on the specific coal
and the desired end results within
specified economic constraints.
• Coal cleaning is becoming more
economic as coal and transporta-
tion costs rise, as coal quality dete-
riorates because of less selective
mining techniques, as utilities need
to increase availability and capac-
ity, and as pollution control require-
ments become more stringent.
• Barriers to expanded coal cleaning
include the need for: better quality
control techniques, improved ash
separation techniques, more data
on the benefits of cleaned coal on
boiler operation, and monetary in-
centives to use or produce cleaned
coal.
• The long-term outlook for in-
creased coal preparation may de-
pend on the ability to produce a low
ash, low sulfur slurry product for
use in (converted) oil-fired boilers.
• The R&D area of greatest short-
term emphasis in the preparation
industry is improving fine coal
washing and dewatering equip-
ment. Long-term R&D will center
around development of low ash,
low sulfur fuels and chemical clean-
ing technologies.
• Promising advanced physical coal
cleaning processes under develop-
ment are the AED process (electro-
static separation technique),
OTISCA process (fine coal specific
gravity separation using an organic
liquid), oil agglomeration (surface
property separation using oil in a
coal/water slurry), and high gradi-
ent magnetic separation (removal
of weakly magnetic ash materials).
• Promising advanced chemical coal
cleaning processes in development
are the Gravimelt (Fe2(SO4)3 basis)
and General Electric (microwave ir-
radiation plus sodium hydroxide
treatment) processes.
SO2 Emission Reductions
Coal cleaning plant design involves a
tradeoff between top size, extent of
cleaning, and energy recovery. Reduc-
ing the top size lowers the potential S02
emissions from the coal. Except for
western coals, a more significant reduc-
tion in S02 emissions is attained by de-
creasing the specific gravity at which
coal is cleaned. The emission reduction
varies from 20 to over 40 percent.
Analysis of coal deliveries to utilities
indicates that the greatest SO2 reduc-
tion from washing (0.8 million tons* of
SO2) could have been achieved in the
State of Ohio, where approximately 70
percent of the coal consumed comes
from the Northern Appalachian region.
Assuming that mandatory washing
were to occur on a regional basis, the
midwestern states would experience
the greatest reduction of S02 emissions
and the southeastern states the least;
the reduction in emissions in the mid-
western states would total 3.2 times that
of the southeastern states.
The total absolute reduction for all the
states considered, if all the coal had
been washed in 1979, would have been
approximately 4 million tons. Of this
total, 3.5 million tons, or 86 percent, of
the reduction would have resulted from
the washing of those coals which origi-
nated in either Northern Appalachia or
the Midwestern state regions. Coals
from the Southern Appalachia, Ala-
bama, Western Midwest, and Western
regions, which constituted 38 percent of
the coals burned, would have ac-
counted for only 14 percent of the abso-
lute S02 reductions from washing all
coals in 1979. From a user standpoint,
most states burn coals originating from
three to six coal-producing states, and
from several coal producing regions. As
a result, any regulations involving coal
*1 short ton x 0.907 = 1 metric ton.
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washing or coal use affect each state
differently.
The ability of a coal to comply with an
emission standard is a function of the
variability in the coal characteristics,
time frame of the emission regulation,
and the amount of coal burned (i.e., lot
size). Blending, coal preparation, and
coal handling attenuate the variability
of the run-of-mine (ROM) coal charac-
teristics. Cleaned coal has less variabil-
ity than ROM coal, and this difference is
greatest for short averaging times and
small lot sizes. Conversely, for long av-
eraging times (e.g., 30 days) and large
lot sizes, the variability is greatly re-
duced and thiere is almost no difference
between ROM and cleaned coal vari-
ability characteristics. The mean coal
sulfur values needed for compliance
must be determined on a case-by-case
basis.
Coal has been found to contain nearly
every naturally occurring element.
Major portions of many trace and minor
elements are associated with the inor-
ganic fraction of the coal as discrete
mineral phases. One way to control
trace element emissions is to remove
the constituents before combustion.
Washability and Preparation
The potential for improving the qual-
ity of a coal by separating mineral com-
ponents from the coal matrix using dif-
ferences in specific gravity is called the
washability of the coal. A washability
analysis evaluates coal characteristics
that indicate how easy or how difficult it
is to improve the quality of the coal by
specific gravity separation. Washability
test results are used by coal preparation
engineers to estimate the yield and
properties of the cleaned coal, to design
coal cleaning circuits, and to select coal
cleaning equipment. The washability
test procedure consists of a screen anal-
ysis followed by a float-and-sink test
and a chemical analysis. The washabil-
ity results can be plotted in a number of
ways to produce a set of curves which
are characteristic of the coal.
The washability data provide infor-
mation on how well various coal clean-
ing circuits may perform. The selection
of the proper cleaning circuit(s) is dic-
tated by the design objective and by a
set of constraints. A typical design ob-
jective might be the minimization of
coal cleaning costs. On the other hand,
constraints can be dictated by product
specifications, environmental regula-
tions, or process requirements. After
the operating characteristics for each
circuit are determined, various pieces of
coal preparation equipment within each
circuit are selected.
Coal preparation operations can be
classified as comminution, sizing,
cleaning, and dewatering. The major
objective of comminution in prepara-
tion plants is to reduce the ROM coal to
sizes suitable for cleaning. Coal can be
sized by air or hydraulic classifiers or by
screens. Cleaning is the step in which
coal is separated from its impurities.
The separation takes place in water, in a
dense medium, or in air. Mechanisms
for physical cleaning are based either
on the specific gravity or on the surface
property differences between coal and
its impurities. Cleaned coal and refuse
streams from wet cleaning need dewa-
tering to meet the product specifica-
tions and refuse landfill disposal re-
quirements. Excessive moisture in the
cleaned coal and refuse is undesirable
because it creates handling problems
and increases transportation costs. In
addition, moisture reduces the heating
value of the cleaned coal, increasing the
boiler fuel requirement.
There are four major levels of clean-
ing:
No Cleaning (Level 1).
Partial Washing (Level 2: Coarse
Cleaning Plant).
Coarse Washing with Partial Washing
of Fines (Level 3: Coarse- and
Intermediate-Size Cleaning Plant).
Total Washing (Level 4: All Size
Ranges Cleaned).
There is no universal approach to pro-
ducing clean coal by physical prepara-
tion techniques. Therefore, a given
preparation process that is effective on
a coal from one seam may be ineffective
on coal from another seam in achieving
a comparable level of cleaning. For this
reason, the coal cleaning approach
must be designed around the specific
coal and the desired end results within
the economic constraints of the situa-
tion.
Two or more coals can be blended as
an alternative to, or in conjunction with,
coal washing. Normally, a coal with a
sulfur content that exceeds a given S02
emission standard is blended with a
lower sulfur coal. For very high sulfur
coals, coarse washing can be combined
with blending to produce a marketable
coal. Blending permits an increase in
the amount of potential compliance
coal and a resultant increase in mar-
ketable coals.
Environmental Impacts From
Washing
Many factors influence the amount
and form of pollutants emitted from
coal cleaning facilities to the surround-
ing environment. Among these factors
are: type of coal, mining methods,
siting and geographical location, clean-
ing process, and level of preparation.
Air
From 1972 to 1974, EPA sampled and
analyzed particulates and off-gas emis-
sions from scrubbers associated with
thermal dryers at coal preparation
plants. Results from EPA's environmen-
tal assessment program indicate that
fugitive dust is not a problem at prepa-
ration plant boundaries. Based on this
study, particulate emissions standards
were promulgated.
Water
The final regulations for coal prepara-
tion plants, as printed in the October 13,
1982, Federal Register, established
NSPS for coal preparation plants at zero
discharge of pollutants. However, in Au-
gust 1983, EPA signed an agreement
with several parties, including the Na-
tional Coal Association, stating that the
regulations would be changed to elimi-
nate the zero discharge requirement.
The presence of trace metals in liquid
waste streams is not unexpected since
they are found in the coal. Wastewater
treatment for the control of pH and sus-
pended solids generally reduces the
trace element concentration in treated
effluents to acceptable levels.
Solids
Present controls for solid wastes from
coal cleaning are in the Surface Mining
Control and Reclamation Act (SMCRA)
regulations. These regulations relate
mostly to reclaimed area stability, burn-
ing, and pollutants leached from the
waste and discharged to water. Control
technologies are mainly construction
and operating standards, which are de-
signed to prevent environmental degra-
dation. Pond sediments and fine waste
solids contain heavy metals and other
elements at concentrations that pro-
duce potential environmental effects.
These elements originate in the coal,
not the cleaning process which is in-
tended to remove incombustibles as re-
fuse from the coal. The high metal con-
centrations in the refuse create the
problem of their ultimate disposal.
Those concentrations also make it evi-
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dent that precautions must be taken to
prevent the migration of these chemi-
cals to groundwater.
Coal preparation involves a tradeoff
between widespread air pollution at
power plants and additional solid and
slurry wastes at preparation plants/
mine sites. For every ton of SO2 re-
moved, from 1 to 20 tons of solid waste
is generated. These quantities vary with
such factors as ash content of the coal,
product specifications, type or level of
washing employed, the method of min-
ing, coal washability, and plant yield.
Cost of Cleaning
A capital cost methodology was de-
veloped based on specific plant circuits,
on their associated capacities, and on a
standard EPA methodology for cost
analysis of air pollution control sys-
tems. The capital cost methodology
was based on the cost of the major plant
items, plus the installed cost of items
outside the basic plant such as silos, ex-
ternal conveyors, and thermal dryers.
Capital costs, as a function of size, were
developed for major preparation plant
unit operations using estimates pro-
vided by suppliers of the cleaning plant
equipment.
Coal cleaning plant operation and
maintenance (O&M) cost estimates
were based on 10 detailed cost esti-
mates obtained from previous studies,
information obtained from a large coal
company, a TVA study, and the Bureau
of Labor Statistics; and on data from an
equipment manufacturer. The overall
O&M costs for a coal cleaning plant in-
clude labor, overhead, supplies, mainte-
nance, contracted services, fuel and
power, thermal dryer heat fuel, and mis-
cellaneous expense. Other factors being
equal, larger plants cost less per ton per
hour input capacity because of econ-
omy of scale. Similarly, operating labor
does not generally increase proportion-
ately with plant size. As coal is cleaned
at smaller top sizes, both labor and cap-
ital cost generally increase. As yield de-
creases, a given size plant has less
throughput with resulting higher cost.
Cost estimates generated by this ap-
proach agreed (i.e., within ±20 percent)
with O&M costs obtained from opera-
tors of existing coal preparation facili-
ties.
Cost Benefits of Coal
Preparation
A procedure was established for iden-
tifying and estimating the relative costs
and benefits to a specific utility associ-
ated with their selection of alternative
sources of coal. The costs and benefits
included:
1. Cleaned Coal Costs
a) ROM Coal Costs
b) Coal Cleaning Plant Operating
and Maintenance Cost
c) Coal Cleaning Plant Capital
Amortization
d) Cost of Mined and Discarded
Material
e) Crushing and Screening Cost
f) Payment to UMW Trust Funds
for Union Mines
2. Transportation Cost
3. Ash Disposal Cost
4. Pulverization Cost
5. Utility Plant Maintenance Cost
6. Boiler Efficiency
7. Boiler Availability
8. Emission Control Cost
The boiler related benefits were derived
from a study of TVA plants performed
jointly for DOE and TVA. The universal-
ity of the relationships in the TVA report
has not been tested, and the report
states that the relationships may not be
directly applicable to eastern and mid-
western boilers. However, this study
represents the most extensive effort to
date to document and quantify power
plant performance measures. The rela-
tionships developed for maintenance
cost, boiler efficiency, and boiler
availability use coal ash, sulfur, and
moisture content, and boiler age as
input variables. Both linear and loga-
rithmic relationships were developed,
depending on the performance meas-
ure studied. The emission control cost
dealt with the cost of flue gas desulfur-
ization. The capital cost of an FGD sys-
tem may be less when using a cleaned
coal with lower sulfur content than the
raw coal. Lower FGD system annualized
costs can also result from a lower capi-
tal amortization burden and lower O&M
cost. When cleaned coal is burned, the
lower SO2 content in the flue gas may
allow some bypassing around the
scrubber section, reducing reagent re-
quirements, fuels for reheat, and sludge
generation and disposal requirements.
Fuel Options Model
On this program, a model was devel-
oped that evaluates the effects of
changes in the S02 emission regula-
tions on the optimum fuel distribution
network and the overall cost of electric
power generation for a utility system.
The model includes the entire coal-fuel
cycle including power plant compo-
nents (e.g., cyclone and pulverized coal
boilers; primary, F.D. and I.D. fans; pul-
verizers, hammermills, and granula-
tors; electrostatic precipitators; flue gas
scrubbers; and solid waste disposal op-
tions), coal mining, coal washing, and
transportation systems. The model was
run for a midwestern utility with 6
power plants and 12 coal sources (4 of
which included the raw coal and associ-
ated clean coal). The results showed
that, for up to a 40 percent overall S02
reduction for the system, cleaned coal
should be used along with increased
use of low sulfur western coals. Past a
40 percent reduction requirement, flue
gas desulfurization from burning high
sulfur raw coals is the preferred S02
control strategy.
Trends in the Coal Preparation
Industry
At present, only 20 to 30 percent of
the nearly 600 million tons of coal con-
sumed annually by electric utilities is
cleaned, a drop of almost 15 percent in
the past 10 years, while the number of
operational cleaning plants has re-
mained constant. Developing circum-
stances, however, are making coal
cleaning more desirable or necessary.
These include: higher coal prices and
transportation costs; diminishing coal
quality due to less selective mining
techniques and increased production of
low quality coals; the need to increase
availability and capacity factors at exist-
ing boilers; stringent air quality stand-
ards; lower costs for improving fuel
quality versus investing in extra pollu-
tion control equipment; and a projected
20 percent increase of coal consump-
tion by eastern and midwestern utilities
in the next 10 years.
Discussions with coal and utility in-
dustry personnel support the relatively
optimistic outlook for coal preparation.
They believe the increase in its use is
likely because:
• High ash contents in ROM coal are
pushing utilities toward cleaning to
meet boiler specifications.
• Current research on the benefits of
cleaning is expected to indicate
considerable savings to utilities.
• Tight markets are forcing coal com-
panies to offer better quality coals
to be competitive.
Arguments against increased cleaning
are based on continuation of current
conditions including increased avail-
ability of western coals, stable oil prices,
and slow orders for new coal-fired units.
To compete in today's coal market,
most large coal companies are cleaning
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high and medium sulfur coals and im-
proving mining techniques. Several in-
dustry representatives stated that they
are investigating modifications at all
their preparation plants to offer better
products to their customers. Blending
the good quality and poorer quality coal
at the preparation plant is becoming
common practice to produce an aver-
age coal blend that meets product
specifications.
Improvements that would encourage
expanded use of coal cleaning include:
• Better quality control in cleaning
• Improved techniques for separa-
tion of fine pyrite
• Data on the benefits accruing to
boilers
• Better control of leachate from
solid wastes
• More information on sulfur re-
moval potential
• Monetary incentives to use or pro-
duce coal (i.e., tax considerations).
Utilities are not opposed to using
cleaned coal; but they are not fully
aware of its advantages (nor are state
regulatory agenices). The Electrical
Power Research Institute (EPRI) is criti-
cally testing the premise that the lowest
cost coal produces the lowest cost elec-
tricity.
Because customers (e.g., utilities) are
generally unfamiliar with the coal clean-
ing process, little incentive has existed
for coal companies to improve prepara-
tion plant design and operation. Three
areas that have seen recent research
activity are (1) preparation circuits,
(2) process controls, and (3) productiv-
ity improvements.
The research and development area
of greatest emphasis in the preparation
industry is improvement of washing
equipment, particularly fine coal clean-
ing and dewatering. This is a direct re-
sult of the high cost of coal, that penal-
izes coal losses to refuse, and increased
fines production from continuous min-
ing equipment.
The long-term outlook for increased
coal preparation by coal companies
may depend on the ability to produce a
low ash (i.e., less than 3 percent) and
low sulfur (i.e., less than 0.5 percent)
coal suitable for use with coal/water
mixtures in converted oil-fired boilers
and in synthetic fuel facilities. Current
physical cleaning alone cannot reduce
the sulfur to 0.5 percent for most coals.
The problems are that large-scale re-
search is needed to produce this type of
fuel, but the research funds are limited.
Advanced Coal Cleaning
Processes
To overcome the limitations and
shortcomings of the coal preparation
technology, various advanced coal
cleaning processes have been devel-
oped. These processes can be classified
as (1) those that remove sulfur by reac-
tion with a chemical agent and (2) those
that use alternative concepts for im-
proved removal of pyritic sulfur from
fine coal.
DOE has selected the Gravimelt and
the General Electric processes as the
most promising chemical coal cleaning
processes; therefore this report de-
scribes these two processes in detail.
Various concepts have been pro-
posed and tested to improve pyritic sul-
fur removal from fine coal. Four physi-
cal concepts for the removal of pyritic
sulfur are discussed: (1) the OTISCA
process uses specific gravity separation
in an organic liquid; (2) the AED process
separates pyritic sulfur and ash by
means of electrostatic forces; (3) the
high gradient magnetic separation
processes use magnetic forces to re-
move coal impurities; and (4) the oil ag-
glomeration processes separate ash
and pyrite from coal using the principle
of surface property difference.
Current Research in Coal
Preparation
A significant amount of research and
development activities in the 1980s will
be associated with the EPRI Coal Clean-
ing Technology Development Program,
including the Coal Cleaning Test Facil-
ity. The stated objectives of the program
are to: (1) develop engineering data to
improve cleaning plant operation;
(2) develop/demonstrate new and im-
proved coal cleaning equipment; and
(3) develop/demonstrate low ash coal
(less than 0.2 percent ash) cleaning
processes for production of coal/water
slurries.
The Department of Energy continues
to support work on ultra-fine coal char-
acterization and cleaning techniques
and coal washability determinations for
major coal seams. For the late 1980s
DOE research is expected to center
around equipment and circuits that pro-
duce very low ash, low sulfur coal to be
used in coal/water slurries (CWM) or
coal/oil mixtures (COM). The extent and
development of these technologies may
depend on the position EPA takes rela-
tive to gaseous pollutant emissions
from converted boilers.
EPA is sponsoring considerable work
in evaluating coal preparation plant
equipment at the MCCS in Homer City,
Pennsylvania. EPA is also conducting a
number of programs to evaluate the
economics of coal cleaning in combina-
tion with other technologies for con-
trolling S02 emissions.
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A. B. Onursal, J. Buroff, and J. Strauss are with Versar, Inc., Springfield, VA
22151.
James D. Kilgroe is the EPA Project Officer (see below).
The complete report, entitled "Evaluation of Conventional and Advanced Coal
Cleaning Techniques," (Order No. PB87-104 535/A S; Cost: $28.95, subject to
change) will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Air and Energy Engineering Research Laboratory
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
United States
Environmental Protection
Agency
Center for Environmental Research
Information
Cincinnati OH 45268
Official Business
Penalty for Private Use $300
EPA/600/S7-86/017
0000329 PS
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