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At least 487 records · Page 27Linked to original sources
USGS2005

Mapping and prediction of Coal Workers' Pneumoconiosis with bioavailable iron content in the bituminous coals

Based on the first National Study of Coal Workers' Pneumoconiosis (CWP) and the U.S. Geological Survey database of coal quality, we show that the prevalence of CWP in seven coal mine regions correlates with levels of bioavailable iron (BAI) in the coals from that particular region (correlation coefficient r = 0.94, p < 0.0015). CWP prevalence is also correlated with contents of pyritic sulfur (r = 0.91, p < 0.0048) or total iron (r = 0.85, p < 0.016) but not with coal rank (r = 0.59, p < 0.16) or silica (r = 0.28, p < 0.54). BAI was calculated using our model, taking into account chemical interactions of pyrite, sulfuric acid, calcite, and total iron. That is, iron present in coals can become bioavailable by pyrite oxidation, which produces ferrous sulfate and sulfuric acid. Calcite is the major component in coals that neutralizes the available acid and inhibits iron's bioavailabiity. Therefore, levels of BAI in the coals are determined by the available amounts of acid after neutralization of calcite and the amount of total iron in the coals. Using the linear fit of CWP prevalence and the calculated BAI in the seven coal mine regions, we have derived and mapped the pneumoconiotic potencies of 7,000 coal samples. Our studies indicate that levels of BAI in the coals may be used to predict coal's toxicity, even before large-scalen mining.

Environmental Health Perspectives↗
USGS2014

Coal and coalbed-methane resources in the Appalachian and Black Warrior basins: maps showing the distribution of coal fields, coal beds, and coalbed-methane fields

The maps contained in this chapter show the locations of coal fields, coal beds assessed by the U.S. Geological Survey (USGS) in 2000, and coalbed-methane fields in the central and southern Appalachian basin study areas, which include the coal-producing parts of the Black Warrior basin. The maps were compiled and modified from a variety of sources such as Tully (1996), Northern and Central Appalachian Basin Coal Regions Assessment Team (2001), Hatch and others (2003), Milici (2004), and unpublished data from the State geological surveys of Pennsylvania, West Virginia, Virginia, and Alabama. The terms &ldquo;coalbed methane&rdquo; and &ldquo;coal-bed gas&rdquo; are used interchangeably in this report. All of the figures are located at the end of this report. The Appalachian basin historically has been subdivided into three coal regions on the basis of regional geologic structure and stratigraphy: the northern region in western Pennsylvania, eastern Ohio, western Maryland, and northern West Virginia; the central region in west-central and southwestern West Virginia, eastern Kentucky, northern Tennessee, and southwestern Virginia; and the southern region in southern Tennessee, northern Alabama, and northwestern Georgia. The Appalachian basin is one of the most important coal-producing regions in the Nation and the world, and coal has been mined there throughout the last three centuries. The coal is primarily used within the Eastern United States for electrical power generation, but some of it is suitable for metallurgical uses. In 2008, the Appalachian basin produced about 320 million short tons of coal from 1,278 underground and surface coal mines (Energy Information Agency, 2009a). Coalbed-methane production in the Appalachian basin coal regions is an increasingly important resource. In 2008, 247 billion cubic feet (bcf) of coalbed methane was produced in the basin from Alabama (107 bcf), Virginia (101 bcf), West Virginia (28 bcf), and Pennsylvania (11 bcf) (Energy Information Agency, 2009b). Coalbed-methane exploration is ongoing in all of the States in the Appalachian basin coal regions, and production is expected to increase. The study area for most reports in this volume is the Appalachian basin. The term &ldquo;Appalachian basin study area&rdquo; (shortened from &ldquo;Appalachian basin geologic framework study area&rdquo;) includes all of the Appalachian Basin Province (Province 67) and part of the neighboring Black Warrior Basin Province (Province 65) of Dolton and others (1995). The boundaries for these two provinces and the study area are shown on figure 1.

Appalachian basin↗
USGS2019

Self-organizing maps for compositional data: coal combustion products of a Wyoming power plant

A self-organizing map (SOM) is a non-linear projection of a D-dimensional data set, where the distance among observations is approximately preserved on to a lower dimensional space. The SOM arranges multivariate data based on their similarity to each other by allowing pattern recognition leading to easier interpretation of higher dimensional data. The SOM algorithm allows for selection of different map topologies, distances and parameters, which determine how the data will be organized on the map. In the particular case of compositional data (such as elemental, mineralogical, or maceral abundance), the sample space is governed by Aitchison geometry and extra steps are required prior to their SOM analysis. Following the principle of working on log-ratio coordinates, the simplicial operations and the Aitchison distance, which are appropriate elements for the SOM, are presented. With this structure developed, a SOM using Aitchison geometry is applied to properly interpret elemental data from combustion products (bottom ash, fly ash, and economizer fly ash) in a Wyoming coal-fired power plant. Results from this effort provide knowledge about the differences between the ash composition in the coal combustion process.

Stochastic Environmental Research and Risk Assessm↗