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Coal Quality

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Tuesday, January 27, 2015

USGS Compilation of Geographic Information System (GIS) Data Representing Coal Mines and Coal-Bearing Areas in China

USGS Publication: Open-File Report 2014-1219
Geographic information system (GIS) information may facilitate energy studies, which in turn provide input for energy policy decisions. The U.S. Geological Survey (USGS) has compiled geographic information system (GIS) data representing the known coal mine locations and coal-mining areas of China as of 2001. These data are now available for download, and may be used in a GIS for a...

Wednesday, December 17, 2014

Collaborative studies for mercury characterization in coal and coal combustion products, Republic of South Africa

USGS Publication: Open-File Report 2014-1153
Mercury (Hg) analyses were obtained in USGS laboratories for 42 new samples of feed coal provided by Eskom, representing all 13 coal-fired power stations operated by Eskom in South Africa. This sampling includes results for three older power stations—Camden, Grootvlei, and Komati—returned to service starting in the late 2000s...

Friday, November 22, 2013

Petrologic and Isotopic Data from the Cretaceous (Campanian) Blackhawk Formation and Star Point Sandstone (Mesaverde Group), Wasatch Plateau, Utah

USGS Publication: Open-File Report 2013–1254
To better understand the origin and distribution of sodium in these coals, petrologic studies were undertaken within a sedimentological framework to evaluate the timing and geochemical constraints on the emplacement of sodium-bearing minerals, particularly analcime, which previously had been identified in coals in the Blackhawk Formation. 

Wednesday, December 19, 2012

Vitrinite Reflectance Data for Cretaceous Marine Shales and Coals in the Bighorn Basin, North-Central Wyoming and South-Central Montana

USGS Publication: Open-File Report 2012–1254
The purpose of this report is to present new vitrinite reflectance data collected from Cretaceous marine shales and coals in the Bighorn Basin to better characterize the thermal maturity and petroleum potential of these rocks.

Tuesday, November 13, 2012

Mercury and Halogens in Coal

Their Role in Determining Mercury Emissions From Coal Combustion

USGS Publication: Fact Sheet 2012–3122
The USGS domestic and international coal databases and research on trace elements in coal contain much information that is relevant to understanding how Hg in coal occurs and why some coals contain more Hg than others.

Thursday, November 08, 2012

Using simulated maps to interpret the geochemistry, formation and quality of the Blue Gem Coal Bed, Kentucky, USA

Outside Publication: International Journal of Coal Geology
This study presents geostatistical simulations of coal-quality parameters, major oxides and trace metals for an area covering roughly 812 km2 of the Blue Gem coal bed in southeastern Kentucky, USA. The Blue Gem, characterized by low ash yield and low sulfur content, is an important economic resource. Past studies have characterized the Blue Gem's geochemistry, palynology and petrography and inferred a depositional setting of a planar peat deposit that transitioned to slightly domed later in its development.

Thursday, September 27, 2012

Database of the United States Coal Pellet Collection of the U.S. Geological Survey Organic Petrology Laboratory

USGS Publication: Open-File Report 2012–1151
The Organic Petrology Laboratory (OPL) of the U.S. Geological Survey (USGS) Eastern Energy Resources Science Center in Reston, Virginia, contains several thousand processed coal sample materials that were loosely organized in laboratory drawers for the past several decades. 

Friday, June 29, 2012

Geologic Framework and Petroleum Geology of the Bohaiwan Basin Province, China

Includes the Shahejie−Shahejie/Guantao/Wumishan and Carboniferous/Permian Coal−Paleozoic Total Petroleum Systems

USGS Publication: Scientific Investigations Report 2011–5010
This report discusses the geologic framework and petroleum geology used to assess undiscovered petroleum resources in the Bohaiwan basin province for the 2000 World Energy Assessment Project of the U.S. Geological Survey. The Bohaiwan basin in northeastern China is the largest petroleum-producing region in China.

Tuesday, May 01, 2012

Minor element distribution in iron disulfides in coal

A geochemical review

Outside Publication: International Journal of Coal Geology
Electron beam microanalysis of coal samples in U.S. Geological Survey labs confirms that arsenic is the most abundant minor constituent in iron disulfides in coal and that selenium, nickel, and other minor constituents are present less commonly and at lower concentrations than those for arsenic.



The scientists of the U.S. Geological Survey Energy Resources Program use a wide variety of analytical procedures to address key questions and assess evolving trends regarding the use of coal and other solid fuels, such as gas and oil shale. Optimizing fuel use and minimizing its impact on the environment are necessary components of 21st-century strategies for meeting society’s energy needs. One critical aspect of fuel use optimization is an understanding of the geologic factors that affect fuel quality. For example, the composition of coal critically influences power generation efficiency, the impact of coal use on the environment, and the composition and usefulness of combustion products.

In 2008, the U.S. produced about 1,073 million short tons of coal, most of which was used to generate electricity. Impacts of mining this coal include ground disturbance, acid mine drainage, and mobilization of potentially hazardous elements in the coal and the surrounding strata. By understanding the physical processes and chemical reactions that can occur during formation, exploration, and utilization of coal, potential effects on the environment can be predicted. Engineers and industry can then use this knowledge to develop more efficient and cleaner ways to use coal, other solid fuels, and the byproducts of power generation.

Solid fuels can be characterized by standard analytical techniques including organic and inorganic petrography, scanning electron microscopy (SEM) and other electron beam methods, X-ray diffraction (XRD) and X-ray fluorescence (XRF), and inductively coupled plasma atomic emission spectroscopy (ICP-AES) and mass spectroscopy (ICP-MS). A new generation of instruments and techniques for nanoscale analysis may provide greater insights into the genesis, maturation, and geochemistry of solid fuels. Some of these techniques include laser ablation, small-angle scatter neutron scattering (SANS), imaging mass spectrometry (IMS), tip-enhanced Raman spectroscopy, and neutron and X-ray spectroscopies. Combining traditional techniques with these new tools should offer new insight into the formation and evolution of solid fuels. This information, in turn, should allow us to better predict the consequences of utilizing coal.

Leslie Ruppert
Project Chief


Geochemistry of Coal
Geochemistry of Coal

Geochemistry of Coal

Scientists in the USGS Energy Resources Program Geochemistry of Solid Fuels project are working on a variety of research topics... [+]

Mercury in Coal - Geoscientists are working on ways to better understand the distribution of mercury in coal and to potentially reduce mercury in emissions by means of coal preparation. This work builds on previous USGS projects and results obtained from Department of Energy (DOE)-funded collaborative multi-element studies completed nearly a decade ago. Geologists are refining the USGS selective leaching procedure for mercury in coal to optimize mercury mode-of-occurrence determinations. This capability is especially important for coals with ordinary mercury contents because other methods are limited to unusually mercury-rich coals. Geologists are conducting research to optimize micro- or nano-scale approaches to study the distribution of mercury in coal and other solid fuels.

Coal and Coal Combustion Products - Geoscientists at the USGS are completing research designed to quantify and model the elements and compounds in coal and coal combustion products (CCPs) through the coal utilization cycle. Coal quality studies tend to concentrate on single parameters, for example, arsenic or mercury. In contrast, this work takes a comprehensive "cradle-to-grave" approach. The research focuses not only on the occurrence and formation of different elements and compounds throughout the spectrum of mining, production, and transportation, but most importantly, on the utilization and the disposal of CCPs. The cradle-to-grave approach allows us to link in-ground coal quality trends to CCPs, a critical step in predicting environmental effects of coal utilization.

A variety of coal quality parameters including sulfur; major, minor, and trace elements; and coal mineralogy were examined from pulverized-coal power plants in the United States. Five pulverized-coal-fired power plants that utilize different designs and pollution-control devices were sampled in Alaska, Indiana, New Mexico, Ohio, and Wyoming. Two of the power plants receive coal from a single coal bed or coal zone: the Ohio power plant utilizes Upper Pennsylvanian Pittsburgh coal, and the Wyoming plant utilizes Tertiary Tongue River Member of Fort Union Wyodak-Anderson coal from the Powder River Basin. The remaining three power plants receive coal from two to three coal beds or coal zones: the Alaska power plant utilizes beds 3, 4, and 6 from the Middle Miocene Nenana Coal Province; the New Mexico plant is supplied by three unnamed coal beds from the Upper Cretaceous Fruitland Formation coal of the San Juan basin; and the Indiana power plant utilizes Pennsylvanian Stockton coal and an unnamed coal bed from the Illinois Basin. Samples were collected over multiple weeks to ensure that samples of feed coal and CCPs were representative.

Pores in Gas Shales - USGS scientists are collaborating with geoscientists at the Commonwealth Scientific and Industrial Research Organization (CSIRO), Sydney, Australia, and Griffith University, Brisbane, Australia, to examine pores size distribution and connectivity in shale gas using the ultra-high-resolution small-angle neutron scattering (USANS) diffractometer at the National Institute of Standards and Technology (NIST) and the General Purpose Small Angle Neutron Scattering (GP-SANS) diffractometer at DOE’s Oak Ridge National Laboratory (ORNL).

Co-fired Biomass and Coal Studies - USGS scientists are collaborating with geoscientists and engineers at the University of Kentucky Center for Applied Energy Research and East Kentucky Power Cooperative to sample a power plant that has test burns of switchgrass and coal to study the impact of biomass blending on boiler operation and the composition of combustion products.

World Coal Maps - With the increased emphasis on coal usage throughout the world, knowledge of coal resources and reserves, and associated quality and mineability is essential for government and industry planners and policy and decision makers. However, digital data of world coal occurrence are not readily available. USGS has produced geographic information system (GIS) and coal quality data of the coal-bearing areas of the Western Hemisphere and Africa based on existing USGS surficial geology coverages published in Digital Data or Open-File series. However, much of the world’s coal resources occur in the Eastern Hemisphere and a representation of their occurrence and available analytical data needs to be compiled. In 2011, USGS is compiling two new Eastern Hemisphere world coal maps of 1) Pakistan and 2) India and Bangladesh. Additional country maps will be produced in the future.

Data Quality - USGS chemists are providing quality assurance (QA) and quality control (QC) of geochemical analyses to geologists and other geoscientists. Chemists works with geoscientists prior to sample collection and sample submittal to ensure that the correct analyses are selected, that sufficient sample has been collected, and that an adequate number of duplicates, blanks, and QA/QC samples will be submitted to USGS and commercial laboratories.

Participating Scientists

Ronald H. Affolter

Kevin B. Jones

Stephen E. Suitt

Harvey E. Belkin

Allan Kolker
USGS Professional Profile

Sharon M. Swanson

William M. Benzel

Robert C. Milici

Michael H. Trippi

William J. Betterton

Richardo Olea
USGS Professional Profile

Brett J. Valentine

Mark A. Engle

Leslie F. Ruppert


Nicholas J. Geboy

John R. Sanfilipo


World Coal Quality Inventory
World Coal Quality Inventory (WoCQI)

World Coal Quality Inventory (WoCQI)

The USGS Energy Resources Program, in cooperation with many agencies and scientists from the world’s coal producing countries, undertook a project, called the World Coal Quality Inventory (WoCQI), to obtain samples of coal from the world’s producing coal mines during a limited period of time (roughly 1995-2006.

Coal Databases
Coal Databases

Coal Databases

The U.S. Geological Survey Energy Resources Program has developed coal databases to monitor the location, quantity, and physical and chemical characteristics of U.S. coal and coal-related deposits.

Geochemistry Laboratories
Geochemistry Laboratories

Geochemistry Laboratories

The Geochemistry Laboratory supports Energy Team needs for inorganic and organic analysis and maintains a laboratory information system (LIMS) for geochemical data tracking and sample storage. The lab provides geochemical expertise and analytical support to Federal, State and County agencies, universities and foreign research organizations.


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