Availability of the Springfield Coal for mining in Illinois

52 Pages·1999·3.2 MB·English

by  Treworgy, Colin G

IM 118
5
14.66'
Availability of the Springfield Coal
Mining
for in Illinois
Colin G.Treworgy, Christopher P. Korose, Cheri A. Chenoweth, and Daniel L. North
Illinois Minerals 118
Department of Natural Resources
ILLINOISSTATE GEOLOGICALSURVEY
LIBRARY.
Availability of the Springfield Coal
Mining
for in Illinois
Colin G. Treworgy, Christopher P. Korose, Cheri A. Chenoweth, and Daniel L. North
mi
---»«*
Illinois Minerals 118 _ ,.
JAM 2 i 2000
Department of Natural Resources
ILLINOIS STATE GEOLOGICAL SURVEY it *-~» »,.»»..
William W.Shilts, Chief
Natural Resources Building
615 East Peabody Drive
Champaign, IL61820-6964
[phone]
ACKNOWLEDGMENTS
We are especially appreciative to the following mining experts who gave us information on criteria that
limitthe availability of coal: Manny Efframian, Tom McCarthy, David Johnson, George Martin, James
Niemeyerand Monna Nemecek, AMAX Coal Company; Greg Bieri and Philip Deaton, Arch Minerals;
Dan Pilcher, ArclarCoal Company; PhilipAmes, Bruce Dausman, Christopher Engleman and Christo-
pher Padavic, Black Beauty Coal Company; Brent Dodrill, James Hinz, Edward Settle and Randy
Stockdale, Consolidation Coal Company; S.N. Ghose, Dana Meyers, MarvinThompson and John
Williams, Cyprus-AMAX Coal Company; Michael Caldwell, Neil Merryfield and Roger Nance, Freeman
United Coal Mining Company; Dan Ganey andThomas Denton, Kerr-McGee Coal Company;Alan
Kern, Michael Meighan and John Popp, MAPCO Coal Inc.; James Grimm, Midstate Coal Company;
Jeffrey Padgett, Monterey Coal Company; Eric Quam, Old Ben Coal Company; Michael Anderson, Vick
Daiber, Marc Silverman and Grady White, Peabody Coal Company; Robert Gullic and Walter Lucus,
Sahara Coal Company; Steve Short and Dennis Oliver, Sugar Camp Coal Company; Scott Fowlerand
Guy Hunt, Turris Coal Company; Douglas Dwosh, Kenneth Ginard and David Thomas, Weir Interna-
tional Mining Consultants; and Daniel Barkley and Dean Spindler, Illinois Office of Mines and Minerals.
This project was supported bythe U.S. Geological Survey, Department of the Interior, underthe follow-
ing agreements: 14-08-0001-A0773, 14-08-0001-A0841, 1434-92-A0940, 1434-93-A1137, 14-94-
A1266, 1434-95-A01346, 1434-HQ96AG-01460, 1434-HQ97AG-01759 and 1434-98HQAG-2015. We
especiallythank Harold J. Gluskoterand M. Devereux Carter of the USGS fortheirguidence and
support. The views and conclusions contained in this document are those ofthe authors and should not
be interpreted as necessarily representing the official policies, eitherexpressed or implied, of the U.S.
Government. This manuscript is published with the understanding that the U.S. Government is author-
ized to reproduce and distribute reprints for governmental use. The Illinois State Geological Survey
considers its publications to be in the public domain.
Coverphoto: Longwallmining the SpringfieldCoalatKerr-McGee CoalCompany's Galatia Mine.
Editoral Board
Jonathan H. Goodwin, Chair
Michael L. Barnhardt David R. Larson
B. Brandon Curry Donald G. Mikulic
Heinz H. Damberger William R. Roy
Anne Erdmann
L.
LLINOIS
I
UATURAL
RESOURCES
Printedbyauthorityofthe State ofIllinois/1999/500
®
Printedwithsoyinkon recycledpaper
7
CONTENTS
ACKNOWLEDGMENTS
EXECUTIVE SUMMARY
1
INTRODUCTION 2
Coal Resource Classification System 2
Geology and Mining ofthe Springfield Coal 3
Quality of Coal 4
Quadrangle Studies 6
Sources of Data and Limitations of Maps 8
TECHNOLOGICAL AND LAND-USE FACTORS THATAFFECTTHE
AVAILABILITY OF COAL FOR MINING 10
Surface Minable Coal 10
Depth of Seam 10
Thickness of Seam 11
Stripping Ratio 13
Thickness of Bedrock and Unconsolidated Overburden 13
Size and Configuration of Mining Block 14
Land Use 14
Abandoned MineWorkings
1
Surface Mining of Multiple Seams 17
Underground Minable Coal 17
Depth of Seam 17
Thickness of Seam 17
Thickness of Bedrock and Unconsolidated Overburden 22
Thickness of Interburden Between Seams 22
Faults 25
Igneous Dikes 25
Partings 27
Galatia Channel and Dykersburg Shale 28
Size and Configuration of Mining Block 31
Land Use 31
Abandoned Mine Workings 31
Closely-Spaced Oil Wells 31
Potential Land-use Conflicts 32
Sandstone Overlying Coal 32
Turner Mine Shale 32
Weak Floor 32
AVAILABLE RESOURCES 34
CoalAvailable for Underground Mining 36
CoalAvailable for Surface Mining 37
CONCLUSIONS 37
REFERENCES
41
FIGURES
1 Extent of the Springfield Coal in the Illinois Basin 3
2 North-south cross-section ofthe Pennsylvanian System in Illinois 4
3 Depth of the Springfield Coal 5
4 Remaining coal resources in the Illinois Basin 6
5 Annual production of the Springfield Coal in Illinois 6
6 Thickness of the Springfield Coal 7
7 Rank and heat content of the Springfield Coal 8
8 Quadrangle study areas used to identify criteria for coal available for mining 9
13789 36259
9 Problems encountered in surface and underground mines that have overburden
consisting ofthick unconsolidated sediments overthin bedrock 1
1 Thickness of unconsolidated overburden in counties with surface
minable resources of Springfield Coal 1
1 Towns in the vicinity of the Springfield Coal 1
12 State and Federal highways in the vicinity of the Springfield Coal 18
1 Railroads in the vicinity of the Springfield Coal 1
14 Pipelines in the vicinity of the Springfield Coal 20
15 Parks and natural areas in the vicinity of the Springfield Coal 21
16 Thickness of bedrockoverburden, Springfield Coal 23
1 Ratio of the thickness of bedrock to unconsolidated overburden, Springfield Coal 24
1 Effect of interburden thickness on the minability of coal seams 25
1 Areas where the thickness of the interburden between the Herrin and Springfield
Coals may restrict underground mining of the Springfield Coal 26
20 Cross section illustrating multiple, parallel faults displacing a coal seam 27
21 Unmined areas adjacent to one of the faults in the Wabash Valley Fault System 27
22 Areas of Springfield Coal affected by faults and igneous dikes 28
23 Parting in the Springfield Coal in an underground mine nearthe Galatia Channel 29
24 Examples of partings in the Springfield Coal in the Springerton Quadrangle 29
25 Extent of the Dykersburg Shale and the Galatia Channel 30
26 Areas of adverse mining conditions in the Springfield Coal nearthe Galatia Channel 30
27 Areas of Springfield Coal containing closely-spaced oil wells 33
28 Floorsqueeze in an underground mine in Illinois 34
29 Availability of the Springfield Coal for mining in Illinois 34
30 Availability of the Springfield Coal by thickness category 35
31 Availability of the Springfield Coal by reliability category 35
32 Availability ofthe Springfield Coal for underground mining 36
33 Areas of Springfield Coal availablefor underground mining 38
34 Availability of the Springfield Coal for surface mining 39
35 Areas of Springfield Coal available for surface mining 40
TABLES
1 Availability ofthe Springfield Coal for mining in Illinois, billions oftons 1
2 Results of individual quadrangle studies 8
3a Criteria used to define Springfield Coal available forsurface mining in this study
and previous quadrangle studies 11
3b Criteria used to define Springfield Coal available for underground mining in this
study and previous quadrangle studies 1
4 Average total width of fault zone assumed to be unminable 25
5 Availability of the Springfield Coal bythickness category 35
6 Availability of the Springfield Coal by reliability category 35
7 Resources ofthe Springfield Coal available for underground mining 36
8 Resources ofthe Springfield Coal available forsurface mining 41
EXECUTIVE SUMMARY
Of the 65.1 billion tons of original resources of Springfield Coal in Illinois, 63 billion tons or 97%, remain,
the second-largest remaining coal resource in the state. The other2.2 billion tons have been mined or
was lost in mining during the more than 100 years of mining Illinois coal. The degree to which this
remaining resource is utilized in the future depends on the availability of deposits that can be mined at a
cost that is competitive with othercoals and alternative fuels. This report identifies those resources that
have the most favorable geologic and land-use characteristics for mining, shows the probable trend of
future mining of these resources and alerts mining companies to geologic conditions that have a
potential negative impact on mining costs.
Approximately 41% of the original Springfield Coal resources (27 billion tons) are available for mining
(table 1). Available means that the surface land-use and geologic conditions related to mining of the
deposit (e.g. thickness, depth, in-place tonnage, stability of bedrock overburden) are comparable to
othercoals currently being mined in the state. Of these resources, 23 billion tons are 42 to 66 inches
thick and 4 billion tons are greaterthan 66 inches thick.
The available resources are primarily located in the central and southeastern portions of the state and
are well suited for high-efficiency longwall mining. The resources are relatively flat-lying, have a consis-
tent seam thickness over large areas, are relativelyfree of faults, channels, orother geologic anoma-
lies, are located predominantly in rural areas free from oil wells and othersurface development and are
situated in minable blocks of hundreds of millions of tons. Whetheror not the resources are ultimately
mined is still dependent on a variety of otherfactors that have not been assessed, including willingness
of local landowners to lease the coal, demand for a particularquality of coal, accessibility oftransporta-
tion infrastructure, proximity of the depositto markets and cost and availability of competing fuels.
About 62 billion tons ofthe remaining Springfield Coal resources have greaterthan 2.5 pounds of sulfur
per million Btu and are therefore mostly suited forthe high-sulfurcoal market. Only 1.4 billion tons of
the Springfield resources have a sulfurcontent of 0.6 to 1.7 pounds of sulfur per million Btu. However,
the majority of these medium to low sulfur resources (1 billion tons) are classified as available or
available with conditions. Technological factors, such as geologic conditions associated with faults and
channels, are the primary restrictions on mining these lowersulfur deposits.
An additional 3 billion tons of the Springfield Coal resources are available, but have geologic or land-use
conditions that may make them less desirable for mining (table 1). Technological factors (geologic
conditions and engineering parameters such as size of reserve block) restrict mining of 47% of the
resources and land-use factors (e.g. towns, highways) restrict mining of 5% ofthe resources.
Most of the available Springfield Coal resources will have to be mined by underground methods. Of the
63 billion tons of original resources that are at least 75 feet deep (and therefore potentially minable by
underground methods), 41% (26 billion tons) are available for underground mining. An additional 4%
are available but with conditions that make the resources less desirable. These conditions include the
Table 1 Availability of the Springfield Coal for mining in Illinois, billions of tons. Numbers in
parentheses are percent of original resources. Note: surface and underground resources do
not add to the total because coal that lies between 75 and 200 feet deep is included in both
categories.
Potential Mining Method Pounds of Sulfur/M Btu
Total Surface Underground <1.67 >1.67
Original 65.1 7.8 63.0 1.8 63.3
Mined 2.2 (3) 1.1(15) 1.8 (3) 0.4 (23) 1.8 (3)
Remaining 63.0(97) 6.7(85) 61.2(97) 1.4(77) 61.5(97)
Available 27.0(41) 0.9(12) 26.1 (41) 0.8 (46) 26.2(41)
Available w/conditions 2.6 (4) <0.1 (<1) 2.6 (4) 0.2(12) 2.4 (4)
Technological restrictions 30.1 (47) 4.5(57) 29.4 (47) 0.3(16) 29.9(47)
Land-use restrictions 3.2 (5) 1.2(16) 3.0 (5) <0.1 (4) 3.1 (5)
presence of closely-spaced oil wells, less stable roof strata, orclose proximity to developing urban
areas. The majortechnological factors that restrict underground mining are thin interburden between
the Springfield Coal and an overlying seam (17%), coal less than 42 inches thick (14%) and unfavor-
able thicknesses of bedrock and unconsolidated overburden (13%). Land-use restricts underground
mining of 5% of the original resources and 3% have already been mined or lost in mining.
Only about 8 billion tons of the original Springfield Coal resource lie at depths of less than 200 feet and
are potentially minable by surface methods. Of these resources, 15% have already been mined and
12% (just under 1 billion tons) are available forsurface mining. Land-use factors, primarilytowns,
restrict 16% of the resources. Technological factors, primarily stripping ratio and thick unconsolidated
material, restrict 57% of the surface-minable resources.
To avoid high mining costs resulting from unfavorable geologic conditions, companies siting under-
ground mines should avoid areas of thick drift and thin bedrock cover, close proximity to the Galatia
Channel and faults, areas of closely-spaced oil wells and areas at the margins of the Dykersburg Shale.
The areas of low-cost surface minable resources (areas with low stripping ratios that are free of conflict-
ing land-uses) are limited and will only support small, limited-term operations.
This report is one of a series that explain the availability of coal in Illinois forfuture mining. Earlier
reports in the series assessed the availability of coal in 21 study areas. The study areas were 7.5-
minute quadrangles that were representative of mining conditions found in various parts ofthe state.
Coal resources and related geology were mapped in these study areas and the factors that restricted
the availability of coal in the quadrangles were identified through interviews with more than 40 mining
engineers, geologists and other mining specialists representing 17 mining companies, consulting firms
and government agencies active in the Illinois mining industry. The major restrictions identified in these
individual study areas were used forthis statewide assessment ofthe availability of the Springfield Coal
formining.
INTRODUCTION
Accurate estimates of the amount of coal resources available for mining are needed for planning by
federal and state agencies, local communities, utilities, mining companies, companies supplying goods
and services to the mining industry and otherenergy consumers and producers. Current inventories of
coal resources in Illinois provide relatively accurate estimates of the total amount of coal in the ground
(e.g. Treworgy et al. 1997b), butthe actual percentage of the total that has geologic and land-use
conditions favorable for mining is not well defined. Environmental and regulatory restrictions, the
presence of towns and othercultural features, current mining technology, geologic conditions such as
unstable roof strata and otherfactors significantly reduce the amount of coal available formining.
The United States has enormous resources of coal and there is little concern that a shortage of coal
could develop in the foreseeable future. The important issue forsociety is where the greatest resources
that are most favorable for mining are located and how they will be extracted (McCabe 1998). Recog-
nizing that a significant difference exists between the reported tonnage of total coal resources and the
tonnage legally or practically restricted from mining by various land-use and geologic conditions, the
United States Geological Survey (USGS) initiated a program in the late 1980s to assess the amount of
available coal in the United States (Eggleston et al. 1990). As part of this ongoing effort, the Illinois
State Geological Survey (ISGS) is assessing the availability of coal resources forfuture mining in
Illinois. This report assesses the Springfield Coal resources in Illinois and identifies those resources
that have the most favorable geologic and land-use characteristics for mining, shows the probable trend
of future mining ofthese resources and alerts mining companies to geologic conditions that have a
potential negative impact on mining costs.
Coal Resource Classification System
The ISGS follows the terms and definitions of the USGS coal resource classification system (Wood et
al. 1983). With minor modifications to suit local conditions, these definitions provide a standardized
basis forcompilations and comparisons of nationwide coal resources and reserves.
The term "original resources" refers to the amount of coal originally in the ground priorto any mining.
In past reports the ISGS has defined resources as all coal in the ground that is 18 or more inches in
thickness and lying less than 150 feet deep, orcoal 28 or more inches thick and more than 150 feet
deep. In this report the ISGS defines surface minable coal as all coal in the ground that is 18 or more
inches thick and lying less than 200 feet deep and underground minable coal as all coal 28 inches or
more thick and lying 75 or more feet deep. Note that by these definitions, some resources may be both
surface and underground minable. The USGS and other states use 14 inches (not 18 or 28) as the
minimum thickness for resources. This difference in minimum thickness used to define resources does
not significantly affect the resource totals forthe Springfield Coal, which is commonly thickerthan 28
inches throughout the area of the state where it has been mapped.
Although not yet formally part of the resource classification system, in recent years, the USGS and
many state surveys have made efforts to divide remaining resources into two categories: restricted and
available (Eggleston et al. 1990). Restricted resources are those that have some land-use ortechno-
logical restriction that makes it unlikelytheywill be mined in the foreseeable future. Land-use restric-
tions include man-made or natural features that are illegal or impractical to disturb by mining.
Technological restrictions include geologic or mining-related factors that negatively impact the econom-
ics orsafety of mining. Resources in the available category are not necessarily economically minable
at the present time, but the term designates that these deposits are expected to have mining conditions
comparable to those currently being successfully mined. Determining the actual cost and profitability of
these deposits requires furtherengineering and marketing assessments.
In this study, the ISGS uses an additional category called "available with conditions". This term is used
to designate resources that are not restricted by the land-use ortechnological restrictions, but that have
some known special condition that makes them less favorable for mining. Close proximityto rapidly
developing urban areas, the presence of numerous, but not excessive, oil wells, and potentially un-
stable roof conditions are examples of conditions that resulted in resources being placed in this cat-
egory. In this study therefore, remaining resources = resources restricted by land use + resources
restricted bytechnology + resources available with conditions + available resources.
The USGS classification system uses the terms of measured, indicated and inferred to indicate the
reliability of resource estimates based on the type and density of data (Wood et al. 1983). The ISGS
uses similarcategories, which, in previous reports, have been called Class la, Class lb and Class Ma
(Treworgy et al. 1997b). Because these earlier ISGS categories are essentially equivalent to the USGS
categories, the USGS terminology was used in this report. Collectively, the resources in these three
categories are termed "identified resources" to distinguish them from resources based on less reliable
estimates. In this report, the term resources refers to identified resources as defined byWood et al.
(1983).
Geology and Mining
linois
of the Springfield Coal
The Springfield Coal underlies about two- G3Springfield Coal
thirds of Illinois as well as portions of western [TIHExtentofPennsylvanian System
Indiana and western Kentucky (fig. 1). The
coal crops out along the margins of the Illinois
Basin and reaches a maximum depth in
Illinois of about 1,300 feet (figs. 2 and 3).
Remaining identified resources of Springfield
Coal in the three states total 82 billion tons, of
which 76% (62 billion tons) are in Illinois (fig.
4; Indiana and Kentuckytotals from Carol
Conolly and JerryWeisenfluh, respectively,
personal communication). This represents
about 31% and 30% of all the identified coal
resources in Illinois and the Illinois Basin,
respectively. The Springfield Coal has been
Figure 1 Extent of the Springfield Coal in the Illinois Basin.
Well locations
Elev
I I I I
-1,000
-1,500-
-2,000
Figure 2 North-south cross-section of the Pennsylvanian System in Illinois.
mined in Illinois forwell over 100 years (fig. 5). In 1998, five Illinois mines produced a total of 12 million
tons from the Springfield Coal; approximately 30% of total state production (Illinois Office of Mines and
Minerals, personal communication). The thickest resources of Springfield Coal in Illinois are found in
the central part of the state around the city of Springfield and in the southeastern part of the state along
the Galatia Channel (fig. 6). Recent and historical mining ofthe coal has been concentrated in these
areas and in shallow surface minable deposits west of the Illinois River. The coal is thin or absent in the
southwestern and extreme northern portions ofthe coal field.
Quality of Coal
The Springfield Coal is a high volatile, bituminous coal that ranges in rankfrom rankA in the southeast-
ern corner ofthe state to rank C in the northwestern two-thirds of the state (fig. 7). Overthe same area,
heat content ranges from more than 25 million Btu perton to less than 20 million Btu perton (as re-
ceived). Ash is commonly in the range of 9 to 12% (as received), with slightly lower ash contents
reported in the southeastern part of the state. The sulfurcontent of the coal is commonly in the range of
3to 5% (as received) exceptforareas in southeastern Illinois associated with the Galatia Channel (fig. 6).
In these areas the sulfurcontent of the coal is as low as about 1%. Chlorine content of the coal is
looselycorrelated to depth and increases from <0.1% (as received) at shallow depths along the mar-
gins of the basin to >0.6% in the central part of the basin (Chou 1991). Chlorine content in British coals
has been correlated with corrosion and fouling of high-temperature boilers, but no studies orfield
experiences have reported or been able to confirm such a correlation with respect to chlorine in coals
from Illinois (Monroe and Clarkson 1994, Chou et al. 1998 and 1999).
The quality of coal was not considered as a factor in determining the availability of coal. Although
quality of coal is an extremely importantfactor in individual sales contracts and the magnitude of
demand forcoal, availabilityfor mining of a specific deposit of Springfield Coal cannot be ruled out
based strictly on coal quality. Because most ofthe Springfield Coal resources have a relatively high
sulfurcontent, the demand forthese resources is currently limited. However, the market for high sulfur
coal, though reduced in size, is expected to continue and may even increase as power plants with new
emission control technologies come on line. To identify what portion of the Springfield resources are
available to meet that demand, available resources are classified by sulfurcontent. Alogical continua-
tion of this study would be to furthercharacterize coal resources by otherquality parameters important
to the marketing of coal (e.g. ash, chlorine, trace elements). However, much more coal quality data are
needed to make such a characterization feasible.