U.S. Geological Survey Coal Quality (COALQUAL) Database Version 3.0.

摘要

Coal has often been described as one of the most difficult materials to sample because of its inherent heterogeneity. Therefore, fundamental to any coal assessment is an understanding of the impacts of the geological heterogeneity on coal quality variability for a given area. Since the mid-1970s, the U.S. Geological Survey (USGS) has maintained a coal quality database of national scope named USCHEM, which currently contains data for over 13,000 samples. A subset of the USCHEM database called COALQUAL Version 1.3 was initially published in 1994. Version 3.0 of the COALQUAL database represents a major editing effort to resolve some of the DOS software limitations used by earlier versions of the database. Because of database size limits during the development of COALQUAL Version 1.3, many analyses of individual bench samples were merged into whole coal bed averages.