Geology topics
Linda J. Bragg
Publications and source records attributed to Linda J. Bragg.
The World Coal Quality Inventory: South America
Executive Summary-Introduction: The concepts of a global environment and economy are strongly and irrevocably linked to global energy issues. Worldwide coal production and international coal trade are projected to increase during the next several decades in an international energy mix that is still strongly dependent on fossil fuels. Therefore, worldwide coal use will play an increasingly visible role in global environmental, economic, and energy forums. Policy makers require information on coal, including coal quality data, to make informed decisions regarding domestic coal resource allocation, import needs and export opportunities, foreign policy objectives, technology transfer policies, foreign investment prospects, environmental and health assessments, and byproduct use and disposal issues. The development of a worldwide, reliable, coal quality database would help ensure the most economically and environmentally efficient global use of coal. The U.S. Geological Survey (USGS), in cooperation with many agencies and scientists from the world's coal producing countries, originally undertook a project to obtain representative samples of coal from most of the world's producing coal provinces during a limited period of time (roughly 1998-2005), which is called the World Coal Quality Inventory (WoCQI). The multitude of producing coal mines, coal occurrences, or limited accessibility to sites in some countries can preclude collecting more than a single sample from a mine. In some areas, a single sample may represent an entire coal mining region or basin. Despite these limitations in sampling and uneven distribution of sample collection, the analytical results can still provide a general overview of world coal quality. The USGS intends to present the WoCQI data in reports and, when possible, in Geographic Information System (GIS) products that cover important coal bearing and producing regions.
Mercury in U.S. coal; abundance, distribution, and modes of occurrence
The U.S. Geological Survey (USGS) has compiled a nationwide coal information database over the last 25 years. A subset of the data, called COALQUAL, contains analyses of over 7,000 coal samples that have been collected or calculated to represent the entire thickness of a coal bed in the ground. The COALQUAL database is an extremely valuable source of information for raw or in-ground trace-element concentrations in U.S. coals and, if adjusted for the effect of coal cleaning in appropriate coals, can provide a first estimate of as-shipped mercury concentration in coal where data are not available.
Map showing structure contours and overburden thickness isopleths of the Pittsburgh coal bed in Pennsylvania, Ohio, West Virginia, and Maryland
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Chemical analysis of 45 Maryland coal samples
This report is part of a continuing program by the U.S. Geological Survey, State Geological Surveys, and the Coal Analysis Section of the U.S. Department of Energy to provide chemical data on the composition of important coal beds of the United States of America. Such data are useful in determining the economic value of a coal, environmental effects of coal mining and coal use, and the adaptability of a coal to cleaning and to other technological processes of coal treatment and usage.
Chemical analysis of 659 coal samples from the eastern United States
This report includes the analytical data on 659 coal samples from 8 States east of the Mississippi River. The number of samples from each State are: Pennsylvania, 132; Ohio, 101; Maryland, 25; West Virginia, 254; Virginia, 33; Indiana, 49; Massachusetts, 5; and Rhode Island, 10. The analytic data are filed in the National Coal Resource Data System of the U.S. Geological Survey. The U.S. Geological Survey has quantitatively determined 35 major, minor, and trace elements in each sample. Tests were also made for 35 other trace elements using semi-quantitative spectrographic methods. In addition, the Coal Analysis Section of the U.S. Department of Energy has determined proximate and ultimate analyses, 3cu, forms of sulfur, free-swelling indexes, and ash-fusion temperatures on 563 of the 659 samples. Comparison of the geometric means of the 644 bituminous coal samples of this report with an additional 968 bituminous coal samples of the eastern United States reported by Swanson and others in 1976 and by Zubovic and others in 1979 is shown in tables 2a-c. As shown by the means for ultimate and proximate analyses, small differences exist between the two sets of data; however, only the moisture and oxygen contents are significantly different. The forms of sulfur, ash-fusion temperature and heat of combustion are similar. The means for the major and minor oxides in ash are similar for SiO 2 , K 2 O, Fe 2 O 3 , TiO 2 , MgO, and P 2 O 5 are lower, whereas, MnO is higher in the analyses of the samples of this report. Eighteen of the means for the trace elements in the coal are about equal for the two sets of samples. Only As, Co, La, Li, and Pb are significantly higher, whereas, Ag, B, Ba, Be, Cd, Cs, F, Ge, Mo, Nb, and Nd are lower in the in the 64L,bituminous coal samples of this report.