Coal Recovery from Mine Wastes of the Historic Longwall Mining District of North-Central Illinois

摘要

Recovery of coal from mine wastes produced by historic longwall mines in northeastern Illinois was studied as part of a project undertaken in 1982 for the Illinois Abandoned Mined Lands Reclamation Council. About 100 of these mines operated in the Wilmington and La Salle Districts of the Illinois Coal Field between about 1870 and 1940; all worked the Colchester (No. 2) Coal Seam, using a manual high-extraction mining method. Large samples of the three major kinds of mine waste-gray mining gob, preparation gob, and preparation slurry-were collected from deposits at nine of the larger mine sites and analyzed to determine their general ranges of sulfur, ash, and heating values. Preparation gob and slurry from six of the sites had significant combustible contents, and were evaluated by a simple procedure in which ash analyses and wet-screening tests were used to determine the washability and yield of combustibles to recovery processes.