United States
Environmental Protection
Agency
Industrial Environmental
Research Laboratory
Research Triangle Park NC 27711
Research and Development
EPA-600/S7-84-036 May 1984
Project Summary
Mineral Matter and Trace
Elements in the Herrin and
Springfield Coals, Illinois Basin
Coal Field
R.D. Harvey, R.A. Cahill, C.-L. Chou, and J.D. Steele
This study investigated the variability
and regional distribution of chemical
elements and mineral impurities in
Springfield and Herrin Coals—the two
principal coal beds mined in the Illinois
Basin Coal Field.
Analytical determinations were made
for 67 elements and related chemical
parameters and for 8 mineralogical
components in 102 newly collected
samples. The resulting data were
combined with data previously obtained
for 128 other samples.
The greatest variation of elemental
concentrations in the Herrin Coal,
found within benches in vertical sections
through the seam, is due to changes in
the mineral composition of the respective
benches. The variability of elements in
channel samples also differs from area
to area in the Illinois Basin; most
important is the variation of the chalco-
phile metals associated with the mineral
pyrite (FeS2). Metals of environmental
concern decrease in relative variability
. (standard deviation/mean) in the follow-
ing order: Cd, Zn, As. Pb. and Sb. All
other such metals vary in lesser amounts
(standard deviation/mean generally
less than 1).
The mean concentration (in ppm) of
these and other metals in both coals
decreases in the following order: Pb
(28), Cr and Ni (18), Cu (12.5). As (11),
Mo (9.2), and Se (2.4). All other trace
metals of environmental concern aver-
age less than 2.4 ppm. Sulfur averages
3.5 percent and has a comparatively
low variability (standard deviation/
mean of 0.35).
Washability tests confirm that ele-
ments associated with the mineral matter
can be more easily removed from the
coal than can organic-associated ele-
ments. Estimates of the average con-
centration (in ppm) in washed coals are:
Pb and Ni (17). Cr (15), Cu (9), Mo (5),
As (4). Se (2), Th (1.7), Cd (<1.5), and
Be (1.4). All other metals of environ-
mental concern are estimated to aver-
age less than 1 ppm in washed coals.
This Project Summary was developed
by EPA's Industrial Environmental
Research Laboratory. Research Triangle
Park, NC, to announce key findings of
the research project that is fully docu-
mented in a separate report of the same
title (see Project Report ordering infor-
mation at back).
Introduction and Summary
Coal provides about 20 percent of the
energy consumed in the U.S.; about 70
percent of the coal produced in 1980
(some 600 million tons) was used for
electric power generation. Two coal beds
(seams), the Herrin Coal Member and the
Springfield Coal Member, extend over
much of the Illinois Basin Coal Field,
which includes southwestern Indiana
and western Kentucky. These two seams
account for more than 90 percent of the
coal produced from the coal field and
about 73 percent of the resources
remaining in the field. It is expected that
large quantities of coal will continue to be
mined from these two coals.
The National Research Council Panel
on Trace Element Geochemistry of Coal
-------
Resource Development Related to Health
has identified 33 elements commonly
found in coals to be of potential environ-
mental concern. The primary objective of
this study was to compile a data base on
the characteristics and distribution of
these and other elements in the two
seams throughout the Illinois Basin Coal
Field. Because of the expected association
of many of these elements with mineral
matter in the coals, another major
objective was to investigate the mineral-
ogical composition of the coals, and
evaluate the results in terms of the
elemental composition.
Other study objectives were: (1) to
determine local and regional variations of
chemical and mineral components in the
two most important commercial seams in
the Illinois Basin; (2) to assess the
abundance and variation of the trace
elements of environmental concern; and
(3) to investigate the spatial distribution
of the trace elements and mineral
components throughout the coals to
facilitate prediction of the properties of
the two coals in unexplored areas of the
basin.
Analytical Methods
Methods used for the analytical deter-
minations include standard coal chemical
tests, atomic absorption, instrumental and
radiochemical neutron activation analyses,
x-ray fluorescence, energy dispersive x-
ray, optical emission, ion selective
electrode, low-temperature ashing, x-ray
diffraction, and scanning electron micro-
scopy.
Variation of Elemental
Concentrations
The elemental composition of layers
(benches) within the Herrin (observed in
23 bench samples from four locations in a
single mine) differs considerably from top
to bottom within the seam. The variations
in concentration (represented by the ratio
of the maximum/minimum compositional
values exclusive of the shale partings
present) differ from element to element.
Of those elements of potential environ-
mental concern, Ba varied most in its
concentration in the Herrin—up to 34
times its minimum value. Concentrations
of other elements, in decreasing order of
maximum/minimum (ratio), are: As and
Zn (17), Tl (16), Li (15), and Sb, Th, and Pb
(10). All other elements of environmental
concern have smaller variations in
concentration. However, nearly all samples
in the bench study sets were so low in U
and Cd (<1 and <1.3 ppm, respectively),
that precise variations of these elements
could not be determined.
Variations in the elemental composi-
tion of the whole coals seam were
measured by the mean and standard
deviation (SD) of analytical results on
individual whole-coal (channel equiva-
lent) samples that represent the entire
thickness of the bed at each collection
site. The means and SDs of the elemental
composition of the two coal seams are
given in Table 1. Comparison of the
means for the two indicates that they are,
on the average, quite similar; however,
they do depart from this trend in some
important aspects in some places in the
coal field. The tabulated averages show
that S is only slightly higher in the
Springfield than the Herrin. The differ-
ences (Table 1) in the averages for Zn, Ba,
and P between the Springfield and the
Table 1. Mean Concentration and Standard Deviation (SD) of Elements in Herrin and Springfield Coals
Herrin Springfield Herrin
Springfield
Element
Ag
Al
As
B
Ba
Be
Br
Ca
Cd
Ce
Cl
Co
Cr
Cs
Cu
Dy
Eu
F
Fe
Ga
Ge
Hf
Hg
1
In
K
La
Li
Lu
Mg
Units
PPm
%
ppm
PPm
PPm
ppm
PPm
%
PPm
PPm
%
PPm
ppm
PPm
PPm
PPm
ppm
ppm
%
PPm
PPm
ppm
ppm
PPm
PPm
%
PPm
PPm
ppm
%
Mean
0.06
1.37
8.
127.
86.
1.5
12.8
0.7
2.2
15.4
0.18
6.0
20.2
1.3
12.8
1.1
0.28
70.9
1.87
4.2
5.0
0.57
0.16
1.4
0.1
0.18
7.64
21.1
0.11
0.05
SD
0.04
0.35
19.
39.
105.
0.7
7.2
0.4
9.5
7.8
0.17
2.9
8.6
0.5
4.4
0.4
0.12
31.8
0.74
2.3
4.5
0.2
0.11
0.9
0.08
0.04
3.7
17.3
0.05
0.02
Sam."
35
68
68
59
52
68
61
68
15
57
63
68
68
57
68
57
57
68
68
68
68
57
68
45
57
68
57
21
57
68
Mean
0.06
1.12
14.5
108.
230.
1.5
11.9
0.7
1.3
13.8
0.16
4.4
15.9
1.1
12.2
1.1
0.3
62.9
2.04
3.4
6.1
0.51
0.17
1.3
0.1
0.18
7.13
10.9
0.12
0.04
SD
0.04
0.41
14.6
39.
547.
0.7
8.5
0.5
4.5
9.2
0.16
2.2
6.4
0.5
10.2
0.8
0.2
26.7
0.92
1.6
3.5
0.19
0.11
1.2
0.1
0.09
4.2
8.0
0.09
0.03
Sam.'
29
50
50
50
31
50
43
50
48
40
47
50
50
40
50
40
40
50
50
50
50
40
48
22
40
50
40
19
40
50
Element
Mn
Mo
Na
Ni
P
Pb
Fib
S
Sb
Sc
Se
Si
Sm
Sr
Ta
Tb
Th
Ti
Tl
U
V
W
Yb
Zn
Zr
Ash
Units
ppm
ppm
ppm
ppm
ppm
ppm
ppm
%
ppm
ppm
ppm
%
ppm
ppm
ppm
ppm
ppm
%
ppm
ppm
ppm
ppm
ppm
ppm
ppm
%
Mean
54.4
9.3
828.
19.8
80.
28.1
17.6
3.46
0.91
2.96
2.35
2.72
1.38
36.5
0.16
0.19
2.33
0.07
0.9
1.6
29.3
0.55
0.58
310.
38.9
12.3
SD
39.
5.5
770.
8.7
198.
35.2
6.4
1.26
0.91
0.88
1.16
0.67
0.67
36.
0.06
0.09
0.79
0.02
0.9
1.4
10.1
0.4
0.2
809.
27.9
2.6
Sam."
68
68
68
68
68
68
57
68
68
57
68
68
57
52
57
49
57
68
44
57
68
57
57
68
58
68
Mean
56.1
9.1
596.
15.1
80.
27.5
15.3
3.66
1.15
2.38
2.56
2.34
1.4
28.8
0.16
0.19
1.95
0.06
1.3
1.3
32.3
0.6
0.5
164.
30.7
11.7
SD
39.4
5.2
613.
7.0
95.
30.7
7.6
1.24
0.7
1.27
1.5
0.65
1.2
26.
0.12
0.14
1.19
0.02
1.5
0.9
23.8
0.7
0.3
214.
26.
2.3
Sam."
50
50
49
50
50
50
40
50
50
40
50
50
40
31
40
36
40
50
21
40
50
40
40
50
43
50
"Number of samples.
-------
Herein are not significant considering the
large variation between samples from the
same seam—as indicated by the relative-
ly high SDs for these elements.
Other elements in whole coal samples
that also have high variations relative to
the mean assay in both seams are As, Cd,
In, and Pb. Sb is more variable in the
Herrin Coal than in the Springfield, and
Be and W are more variable in the
Springfield Coal. Cr, F, Hg, Mo, Ni, Se, S,
and U have low variabilities, relative to
the mean, in both coals.
the high variations for these elements
are due in large part to the patterns of
regional distribution (Table 2). In the
Herrin Coal, As, Cd, Cu, Pb, and Zn all
show a pattern of relatively high concen-
tration in the northwestern part of the
coal field (northwestern Illinois). The data
also confirm previous reports of coal
relatively low in S in areas of the Herrin
Coal adjacent to the Walshville channel
in southern Illinois and in areas of the
Springfield adjacent to the Galatia
channel in southeastern Illinois/south-
western Indiana.
Table 2 also gives the mean concentra-
tions, common ranges, and maximum
concentrations of the elements of envi-
ronmental concern in both beds. All trace
elements of environmental concern
average less than 28 ppm (Pb) in the raw-
unwashed coal samples. Data on ele-
ments of environmental concern in the
two Illinois Basin coals are summarized
and compared with data on coals from
other areas in Table 3.
Implications of Results for
Washed Coal Products
The compositional data in Table 1 are
based on channel samples (major mineral
parting excluded) and therefore apply to
coal from the mine after a minimal
amount of cleaning. Of interest are the
elemental concentrations of coal products
after washing in modern coal preparation
Table 2. Concentration of Chemical Elements and Mineral Matter of Environmental Concern in Samples of Herrin (H) and Springfield (SJ Coals
and Trends in Regional Distribution
Whole-coal samples
Common
Units Mean range
Estimated
average
for washed
Maximum coals
Regional distribution in the
Illinois Basin Coal Field*
CHEMICAL ELEMENTS
"As
Be
"Bo
"Cd
Cr
Cu
°Pb
"MO
Ni
"Se
Tl
Th
U
MINERAL MATTER
Calcite
(CaCOa)
Clays
(A/-Silicates)
Pyrite
(FeSi)
Quartz
(SiOi)
Ash (750"C)
LTA
ppm 11 2-20 61 4 H: >6 clustered in NW and SO IL
S: >10 mostly along Galatia channel
ppm 1.5 1.1-1.9 3.9 1.4 H & S: no apparent trends
ppm 118 40-200 225 113 H: somewhat higher values in W IL
S: somewhat lower values along the
Galatia channel
ppm 1.5 <5. 65 <1.5 H: >5(?J clustered in NW and SE IL
S: >5f?f clustered in NW and SE IL
ppm 18 14-22 60 15 H & S: no apparent trends
ppm 12.5 7-17 67 9 H: higher values in NW IL
S: no apparent trend
ppm 68 10-125 262 50 H & S: no apparent trends
ppm 28 11-45 2O6 17 H: >50 mostly in NW, EC and SE IL
S: >30 mostly in SE IL
ppm 0.16 0.1-0.2 0.71 0.13 H. X7.2 mostly in NW IL
S: >0.3 (few), scattered
ppm 9.2 6-12 29 5 H & S: no apparent trends
ppm 18 14-22 46 17 H: higher values in NW IL
S: no apparent trends
ppm 2.4 2-3 8.5 2 H & S: no apparent trends
ppm 0.06 0.04-0.08 0.18 0.04 Insufficient data
% 3.5 2.8-4.2 8.4 2.6 H: lower values in certain areas
near Walshville channel
S: lower values in certain areas
near Galatia channel
ppm 1.0 0.3-2.2 7.2 0.5 H & S: no apparent trends
ppm 2.2 1.7-2.7 7.6 1.7 H: >3 scattered
S: >2 scattered
ppm 1.5 0.5-2.9 9.3 1.5 H & S: no apparent trends
% 1.3 0.8-1.8 5.2 - H & S: no apparent trends
% 8.5 7.2-9.8 19.1 - H & S: no apparent trends
% 3.4 2.4-4.4 11.6 - H & S: same as sulfur above
% 2.3 1.8-2.8 5.4 - H & S: no apparent trends
% 12.1 9-15 22.9 - H. lower values in areas near
Walshville channel and in KY
S: lower values in certain areas
near Galatia channel and in KY
% 15.5 12-19 28.1 - H & S: same as Ash above
*H=Herrin Coal; S=Spr/ngfield Coal; NW=northwestern; EC =east central; SE=southeastern; SO=southern; W=western.
"Elements of greatest potential environmental concern; all other chemical elements listed are of moderate potential concern.
3
-------
plants. In such plants in the Illinois Basin,
about 70-85 percent of the raw coal
mined at many sites is recovered for
marketing from washing plants. Compu-
tations utilizing an 80 percent weight
recovery were applied to the four sets of
washability tests conducted for this
study, and the average reduction for the
various elements was determined (Table
4). Although there was appreciable
variation of reduction of certain elements
in the four sets, the averages listed
provide useful trends.
One group of elements, classified as
inorganic (mineral)-associated elements,
shows an average reduction of from 40 to
75 percent. In contrast, other elements
classified as organic-associated elements
show average reductions of 0 to 8.6
percent. The middle group, classified as
mixed-associated elements, show inter-
mediate reductions from 15 to 30
percent. These predicted reductions of
elemental concentrations allow estimates
to be made of the concentrations expected
in washed coals from the two seams
investigated. These estimated concentra-
tions are shown in Table 4.
Departures from these average con-
centrations are likely to exist in marketed
coals from the Illinois Basin. The range of
departures is likely to be of the order of
the standard deviation observed for the
elements (Table 1). Departures are likely
to be the greatest for those elements in
the mixed- and organic-associated groups,
and not so great for elements in the
inorganic association classification, be-
cause of the ease of removal of the heavy
minerals, especially pyrite. Typically, half
of the pyrite occurring in Illinois coals is
removed by washing to the 80 percent
recovery level. Thus, elements associated
with pyrite (As, Ba, Cd, Pb, and Zn) are not
expected to show as wide a variation in
concentration in washed coals as they do
in the channel samples tested.
Conclusions and
Recommendations
Predicted concentrations of elements
of potential environmental concern in
coals that have been washed by float/sink
methods are quite low, except for S
(Table 4). The concentration of those
elements that are associated with high
density minerals including pyrite, espe-
cially As, Ba, Li, Mn, Mo, Pb, Tl, and Zn,
will be much lower in washed than in raw
coals. These metals, however, will be
concentrated in the waste materials from
coal preparation plants, thus presenting
some problems regarding their disposal.
Investigation of the extent of the concen-
7able 3. General/zed Comparisons of A verage Elemental Concentrations in Herrin and Spring-
field Coals with Those in Other U.S. Coals1
Metal
As, \
Be, and f
Cu >
Cd |
and f
Cr J
Ni
Pb \
Hg and >
Average concentration in
Herrin and Springfield
coals is:
somewhat lower:
somewhat higher:
about the same (as):
somewhat higher:
about the same (as):
somewhat lower:
somewhat higher:
somewhat higher:
about the same (as):
than the reported
average concentration
in coals mined from:
U.S. bituminous and Appalachian
Northern Great Plains and Rocky
Mountains
U.S. bituminous, Appalachian, and
Northern Great Plains
Rocky Mountains
U.S. bituminous and Appalachian
Rocky Mountains
Northern Great Plains
all others
all others
Sb
'Only metals of potential environmental concern are included in this comparison.
Table 4. estimated Average Concentration of Elements of Environmental Concern in Washed
Coals
Average concentration "Average Estimated average
in whole-coal. Reduction in concentration in
ppm washed coals, % washed coals, ppm
INORGANIC ASSOCIATED ELEMENTS
"As 11.
Ba 140.
"Cd 1.5
Li 16.
Mn 55.
"Mo 9.2
"Pb 28.
Tl 1.0
Zn 25O.
MIXED ASSOCIATED ELEMENTS
Ag 0.06
Co 5.
Cr 18.
Cu 12.5
F 68.
"Hg 0. 16
Na 731.
"S 3.5(%)
"Se 2.4
Sr 33.
Th 2.2
ORGANIC ASSOCIATED ELEMENTS
B 1 18.0
Be 1.5
Br 12.0
Ge 5.5
Ni 18.
Sb 1.0
U 1.4
V 31.6
60
41
?
44
62
44
40
55
75
30
20
16
30
27
21
16
27
15
16
21
3.9
6.5
0
0
4.5
6.0
0
8.6
4.
83.
<1.5
9.
21.
5.
17.
0.5
63.
0.04
4.
15.
9.
50.
0.13
614.
2.6(%)
2.
28.
1.7
113.
1.4
12.
5.5
17.
0.9
1.4
29.
^Calculated at the 80% recovery of coal from washability results.
"Metals of greatest environmental concern.
-------
tration of these metals in coal wastes and
their environmental impact in Illinois
would be beneficial.
High S levels are a serious problem to
the coal industry in the Illinois Basin.
Except for a few Herein samples, the coal
contains too much S to meet existing
emission requirements for use in newly
constructed electric power plants that do
not have desulfurization facilities. To
illustrate this problem, the total S value
"expected" for washed coal (27 percent
reduction) was calculated, then converted
to pounds SOz per million Btu.
Results for the samples from the Herrin
are plotted in Figure 1; those from the
Springfield, in Figure 2. These maps
show that, for washed coals from the
Herrin, only four samples (from locations
adjacent to the southern end of the
Walshville channel) could be considered
for compliance with a 1.2 Ib SOz/IO6 Btu
(512 ng S02/J) emission limit. The maps
illustrate the condition of total combustion
for which no SO2 is removed at the power
plant and all of the S in the washed coal is
converted to SOa- None of the samples
tested from the Springfield coal, calculated
to the washed coal basis, yield less than
1.2lbSOz/108Btu.
IbSOx/IO'Btu
• 1.4-3.9
A 4.0 -6.0
Extent of Herrin Coal
Anvil Rock Channel
Coal Missing
Walshville Channel
Coal Split. Thin or Absent
0
0
Figure 1.
20
30
40 mi
60km
Distribution of sulfur in Herrin Coal, expressed in Ib SOx/10* Btu adjusted to a
washed coal basis.
-------
0
Figure 2.
H>SO2/J06Btu
m 1.4-3.9
A 4.0-6.0
Extent of Springfield Coal
Galatia Channel
Coal Split, Thin or Absent
20 « 40 mi
> 30. * 60km
Distribution of sulfur in Springfield Coal, expressed in Ib SO2/108 Btu adjusted to a
washed coal basis. None of the samples converted to less than 1.2lb SO2/10e Btu.
-------
R. D. Harvey, R. A. Cahill. C.-L Chou. and J. D. Steele are with the Illinois
Department of Energy and Natural Resources, Champaign, IL 61820.
James D. Kilgroo is the EPA Project Officer (see below).
The complete report, entitled "Mineral Matter and Trace Elements in the Herrin
and Springfield Coals, Illinois Basin Coal Field," (Order No. PB 84-174 143;
Cost: $16.00, 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:
Industrial Environmental Research Laboratory
U.S. Environmental Protection Agency
Research Triangle Park, NC27711
-------
United States
Environmental Protection
Agency
Center for Environmental Research
Information
Cincinnati OH 45268
Official Business
Penalty for Private Use $300
PS
* U.S. GOVERNMENT PRINTING OFFICE: 1964-759-102/945
------- |