Interior Coal Province Research Articles

Evaluation of trace elements in U.S. coals using the USGS COALQUAL database version 3.0. Part II: Non-REY critical elements

Coal is a potential source of some valuable elements. In this work, concentrations of 25 critical elements in U.S. coals were evaluated using the COALQUAL Database Version 3.0 aiming to identify best coal sources for potential recovery of critical element. A method was proposed to calculate the mean concentrations of critical elements in U.S. coals, including Li (11.5 ppm), Be (1.9 ppm), Ti (721 ppm), V (21.6 ppm), Mn (50.8 ppm), Co (4.5 ppm), Ga (5.1 ppm), Ge (7.2p pm), Se (2.4 ppm), Zr (30.4 ppm), Nb (3.3 ppm), Sn (1.8 ppm), Sb (1.0 ppm), Ba (266 ppm), Hf (0.77 ppm), and Ta (0.19 ppm).Based on the calculated mean concentrations, a rough estimate indicates that U.S. coals contain a large amount of critical elements that are enough to meet U.S. demands for many years to come, if these elements can be commercially extracted. By comparing with the suggested cut-off grades, we found that 5.8% of the coal samples have Ga concentrations higher than the suggested cut-off grade. The percentages of promising coal samples (higher than cut-off grades) of other elements are below 3%. Results further indicate that despite some variations among elements, bituminous coals from the Appalachian region are likely to have high concentrations of Li, Ga, Be, Se, and Sb which make them a potential source of these critical elements. Bituminous coals from the Interior Coal Province, both Eastern and Western, were found to have relatively high probabilities of having high Ge concentrations. Very limited coal samples were found from mixed regions to have V and Zr concentrations higher than the corresponding suggested cut-off grades.

Chemical Analyses of Middle and Upper Pennsylvanian Coals from Southeastern Kansas

Elemental and chemical analyses and physical tests were conducted on 36 samples of Middle and Upper Pennsylvanian coals from southeastern Kansas. Concentrations of 35 minor and trace elements in these coals were statistically compared with concentrations in coals of similar rank and age from other areas in the western region of the Interior Coal Province, showing that Kansas coals have significantly higher concentrations of copper, arsenic, and lead. The zinc content in Kansas coal samples ranges from 160 to 51,000 ppm (whole-coal basis), the maximum value being the highest zinc value reported for U.S. coals. Cadmium content also has an extreme range, from less than 1.0 to 160 ppm (whole-coal basis), the maximum value being one of the highest cadmium values reported in U.S. coals. The apparent ranks of these coal samples range from high-volatile B to high-volatile A bituminous coal. Most samples of Middle Pennsylvanian coals from the major coal-mining area in Bourbon, Crawford, and Cherokee counties are high-volatile A bituminous coal. Arithmetic mean values for proximate analyses of coals (as-received basis; n = 25) show these coals to be 15.5% ash, 35.3% volatile matter, 45.9% fixed carbon, and 3.3% moisture and to have a heat of combustion of 11,910 Btu/lb. Arithmetic mean values for ultimate analyses of the coals show these coals to be 4.9% hydrogen, 65.3% carbon, 1.2% nitrogen, 5.5% sulfur, and 7.7% oxygen. The geometric mean values of these Kansas coals are 3.03% pyritic sulfur, 1.25% organic sulfur, and 0.2% sulfate sulfur.

Hydrocarbon Source-Rock Evaluation of Desmoinesian (Middle Pennsylvanian) Coals from Part of the Western Region of the Interior Coal Province, U.S.A.

Hydrocarbon Source-Rock Evaluation of Desmoinesian (Middle Pennsylvanian) Coals from Part of the Western Region of the Interior Coal Province, U.S.A.

Developments in Coal in 1989

In 1989, 5424 United States mines in 26 states produced a record 981.8 million tons of coal, an increase of 3.4% from a revised 949.7 million tons produced in 1988. Of this coal, the Eastern coal province produced 47.1%, the western coal provinces (Northern Great Plains, Rocky Mountain, Pacific Coast, and Alaska) produced 32.5%, the Interior coal province produced 14.6%, and the Gulf coal province produced 5.8%. This production distribution is almost identical to that of 1988. Wyoming produced 171.1 million tons of coal from 2 coal provinces, leading the United States for the second consecutive year. Kentucky again ranked a close second with 170.5 million tons of coal from 2 coal provinces. West Virginia again was third with 151.83 million tons, Pennsylvania again was fourth with 71.8 million tons, and Illinois again was fifth with 60.4 million tons. These 5 states produced 63.7% of United States coal production in 1989 compared to 63.4% in 1988. In rank, the total U.S. coal production was 0.3% anthracite, 69% bituminous, 21.7% subbituminous, and 9% lignite. By age, 62% was Pennsylvanian, 30% was Tertiary, and 8% was Cretaceous. The percentage distribution of the production by age is unchanged from 1988. Bituminous coal's share of the production in 1989 increased 3.7% from 1988 at the expense of subbituminous, due to significantly increased production in eastern Kentucky, West Virginia, and Indiana. Lignite production for montan wax extraction has been taking place on a small scale for many years at 1 mine in the Ione field in California and is included for the first time in this report. In Canada in 1989, 29 mines produced 70.51 million MT of coal, a decrease of 0.2% from 1988. The 3 western provinces (Alberta, British Columbia, and Saskatchewan) accounted for 94.3% of Canada's coal production in 1989, a 0.1% decrease from a revised 94.4% in 1988. By rank, 55% was bituminous, 29.7% subbituminous, and 15.3% lignite.

Developments in Coal in 1988

In 1988, 6,109 United States mines in 26 states produced a record 948.8 million (short) tons of coal, an increase of 0.2% from a revised 930.9 million tons produced in 1987. Of this coal, the Eastern coal province produced 47.3%, the western coal provinces (Northern Great Plains, Rocky Mountain, Pacific Coast, and Alaska) produced 32.2%, the Interior coal province produced 14.7%, and the Gulf coal province produced 5.8%. For the first time, Wyoming led the United States by producing 163.6 million tons of coal. Kentucky ranked second with 161.2 million tons, West Virginia was third with 144.9 million tons, Pennsylvania was fourth with 71.8 million tons, and Illinois was fifth with 59.9 million tons. In rank, the total U.S. coal production was 0.4% anthracite, 65.3% bituminous, 25.4% subbituminous, and 8.9% lignite. By age, 62% was Pennsylvanian, 30% was Tertiary, and 8% was Cretaceous. Large-scale lignite production was started for the first time at 1 mine in Arkansas. The increase in coal production and the decrease in the number of coal mines indicates increased coal-mining efficiency in the United States in 1988. A major factor in this greater efficiency was large-scale surface mining of increased quantities of lignite and subbituminous coal in the western and Gulf coal provinces, where coal commonly contains less than 1% sulfur. In Canada in 1988, 29 mines produced 70.5 million MT of coal, a record high and an increase of 15.6% from 1987. The 3 western provinces (Alberta, British Columbia, and Saskatchewan) accounted for 94.3% of Canada's coal production. In rank, 54.6% was bituminous, 28.2% subbituminous, and 17.2% lignite.

Developments in Coal in 1987

In 1987, United States mines in 26 states produced a record 930.58 million (short) tons of coal, an increase of 3.3% from a revised 900.5 million tons produced in 1986. Of this coal, the Eastern coal province produced approximately 48.3%, the western coal provinces (Northern Great Plains, Rocky Mountain, Pacific Coast, and Alaska) produced 29.3%, the Interior coal province produced 16.6%, and the Gulf coal province produced 5.7%. In rank, 0.6% was anthracite, 66.4% was bituminous, 24.6% was subbituminous, and 8.4% was lignite. There were no significant percentage changes in production by coal rank or by coal province from 1986. Operators of 2,335 coal mines in Kentucky led the United States by producing 177.26 million tons of coal. Wyoming ranked second with 146.5 million tons, West Virginia was third with 137.67 million tons, Pennsylvania was fourth with 66.8 million tons, and Illinois was fifth with 60.7 million tons. Canada produced 61.2 million metric tons.

Prevenance, preservation, and transport of the detrital “coffee grounds” of the Mississippi Delta

Detrital organic fragments or “coffee grounds”, common in the swash zone, and in the lee of barrier islands off the Mississippi Delta consists of up to 40% high-volatile bituminous coal particles of medium to coarse sand size (0.25–1 mm). These coal fragments produce both a well preserved Cretaceous-Paleocene flora and a less well preserved Pottsville (Early Pennsylvanian) flora. This Pottsville flora has close affinities with one described by Kosanke (1950) from the Early Pennsylvanian Illinois Basin coals. If the provenance assignment is correct, these coal particles were transported by the Mississippi River a minimum of 1000 miles from the Interior Coal Province to their present locality in the south Pass area of the Mississippi Delta. However, spillage contamination during a century of barge transport within the Mississippi drainage cannot be ruled out as a possible source for the “coffee grounds” coal. High-volatile coals crop out in the Black Warrior Basin in Alabama to the northeast of the delta. If this is a source of the coal, then an entirely different drainage-transport system would be involved. It would invoke drainage from the Appalachian Province southward, with subsequent longshore current transport, westward — along the Gulf Coast shoreline. Heavy-mineral differences exist between these two sedimentary provinces, with the Appalachian-derived heavy minerals dominated by kyanite, staurolite, and tourmaline; and the Mississippi River Canadian Shield source dominated by amphiboles and pyroxenes. The heavy-mineral assemblage recovered from the “coffee grounds” material is more like those of the Mississippi River Province, and dominated by green hornblende. Vitrinite particles of the coals show no evidence of oxidation rims although they have been in oxygenated waters for an extended period of time during transport. The spore preservation is adequate for specific identification, and is further evidence of minimal oxidation. Coal rank analysis and palynoflora identifications provide a dual approach in reconstructing provenance, transport history, and origin of these detrital organic deposits.

Developments in Coal in 1986

In 1986, according to data from state agencies, United States mines in 26 states produced 897.9 million (short) tons of coal, a slight decrease of 0.2% from the revised 900 million tons produced in 1985. Of this coal, the Eastern Coal province produced 48.5%, the Northern Great Plains, Rocky Mountain, and Pacific Coast provinces and Alaska produced 29.2%, the Interior Coal province produced 16.7%, and the Gulf Coal province produced 5.6%. In rank, 0.4% was anthracite, 66.2% was bituminous, 24.9% was subbituminous, and 8.5% was lignite. Operators of 2,465 coal mines in Kentucky led the nation by producing 165.6 million tons of coal. Wyoming ranked second with 135.7 million tons, West Virginia was third with 130.8 million tons, Pennsylvania was fourth with 73.2 million tons, Illinois was fifth with 62.6 million tons, Texas was sixth with 48.5 million tons, Virginia was seventh with 41.8 million tons, Ohio was eighth with 34.7 million tons, Montana was ninth with 33.7 million tons, and Indiana was tenth with 31.9 million tons. A 3.6% decrease in Wyoming's coal production was the first decrease in 18 years. Development of the nation's first underground hydraulic coal mine progressed in Colorado. Surface mines produced 59% of United States coal production in 1986.

Developments in Coal in 1985

In 1985, United States mines in 26 states produced 895.9 million short tons of coal, an increase of less than 1% from 1984. Of this coal, the Eastern Coal Province (mostly the Appalachian region) produced 48.5%, the western United States (the Rocky Mountain, Northern Great Plains, and Pacific Coal Provinces, and the Alaskan coalfields) produced 30%, the Interior Coal Province produced 21%, and the Gulf Coal Province produced 0.5%. In rank, less than 1% was anthracite, 66% was bituminous, 26% (mostly from the western provinces) was subbituminous, and 8% (from Texas and North Dakota) was lignitic. About 2,871 coal mines in Kentucky led the nation by producing a record-breaking 169.6 million tons of Pennsylvanian coal, followed by Wyoming with 140.7 million tons of mostly Tertiary subbituminous coal, and West Virginia, which slid to third place with 127.3 million tons of Pennsylvanian coal. Pennsylvania ranked fourth with 66 million tons of mostly bituminous coal (4% was anthracite), and Illinois was fifth with 60.6 million tons of Pennsylvanian bituminous coal. Surface mines produced 57% of United States coal production in 1985. New mines were developed in all the coal regions. For the first time, a large captive strip mine began lignite production in Louisiana in 1985 to provide fuel for a nearby 750-MW electricity-generating plant.

Developments in Coal in 1984

In 1984, United States mines produced a record high 890.1 million short tons of coal, 13.8% more than in 1983. In 1984, 49% of this coal was produced in the Appalachian region, still the leading coal-producing region in the nation. The Alaskan coalfields, the Rocky Mountain Coal Province, and the Northern Great Plains Coal Province together rank second, and the Interior Coal Province and Gulf Coal Province together rank third in 1984 coal production. Among the states, Kentucky continued to rank first in coal production. Coal mines in Kentucky produced a record 164.7 million tons. West Virginia ranks second with 130.9 million tons, followed by Wyoming with 130.7 million tons, Pennsylvania with 72.3 million tons, and Illinois with 63.9 million tons. All of these states but Wyoming produce Pennsylvanian bituminous-rank coal that contains the greatest heating (Btu) value. Wyoming produces coal that is mostly of Tertiary age and subbituminous rank. Compliance coal (mostly containing only 0.3-0.5% sulfur and 8,100-8,500 Btu/lb) is shipped from Wyoming's Powder River basin to electricity-generating plants in many of the other coal-producing states.

Geochemical Characterization of Rocky Mountain, Northern Great Plains, and Interior Province Coals: ABSTRACT

Statistical summaries of proximate and ultimate analyses, heat of combustion, and content of 36 major, minor, and trace elements were calculated for 37 Eocene, 470 Paleocene, and 419 Cretaceous coal samples from 31 coal fields or areas in the Rocky Mountain and Northern Great Plains coal provinces and for 503 Pennsylvanian coal samples from 14 areas in the Interior coal province. These analyses show that coals within an age group have similar ranges in composition, and that each group has its own distinctive compositional characteristics. Most variability in element content can be related to changes in rank and differences in ash and total sulfur contents. Mean contents of Ca, Mg, Na, Ba, and Sr are related to rank and decrease as apparent coal rank increases from lignite A to high-volatile B bituminous coal. Mean contents of Si, Al, K, Ti, Ga, Li, Sc, Th, V, Y, and Yb increase as the mean ash content increases (correlation coefficients 0.6), suggesting that these elements are present as aluminosilicates, stable oxides, or phosphate mineral phases. Mean contents of Fe, As, Cd, Co, Cu, Mo, Ni, Pb, Sb, and Zn show high correlation with total sulfur. Contents of these elements are low in Paleocene (0.6% sulfur) and Cretaceous (0.7% sulfur) coals, higher in Eocene (1.8% sulfur) coals, and generally highest in Pennsylvanian (3.9% sulfur) coals. The mean contents of B, Be, Cr, F, Hg, Mn, Nb, Se, U and Zr show no direct relationships to changes in rank or ash and total sulfur contents. Decrease in element content with increased rank probably is related to loss o functional groups that act as cation-exchange sites on organic matter. Ash and sulfur contents are dependent on pH-controlled levels of bacterial activity in ancestral peat swamps. End_of_Article - Last_Page 447------------

Surface mine spoil stability evaluation, interior coal province. Volume 1 — Main report. Glossary of terms (Appendix A) and annotated bibliography (Appendix B) : Miller, R P; Douglass, P M; Robinson, R A USBM OFR 78(1)–80, Aug 1979, 330P

Surface mine spoil stability evaluation, interior coal province. Volume 1 — Main report. Glossary of terms (Appendix A) and annotated bibliography (Appendix B) : Miller, R P; Douglass, P M; Robinson, R A USBM OFR 78(1)–80, Aug 1979, 330P

Surface mine spoil stability evaluation, interior coal province, volume 2 — Details of mine visits and detailed procedures of laboratory testing (Appendix C) : Miller, R P; Douglass, P M; Robinson, R A USBM OFR 78(2)–80, Aug 1979, 398P

Surface mine spoil stability evaluation, interior coal province, volume 2 — Details of mine visits and detailed procedures of laboratory testing (Appendix C) : Miller, R P; Douglass, P M; Robinson, R A USBM OFR 78(2)–80, Aug 1979, 398P