The Physical and Chemical Characteristics of Available Materials for Filling Subsurface Coal Mines.
Dunn-JR; Banino-GM; Ernst-WD
NTIS: PB/274-702 Available for Reference At Bureau Libraries :282 pages
Samples were taken of industrial mineral waste materials that are potentially capable of being used for filling underground coal mines for subsidence control in the Pittsburgh and the Scranton--Wilkes Barre areas of Pennsylvania. The samples were subjected to potentially relevant standard tests that are commonly used in the evaluation of soil materials and mineral aggregate materials. Measurments of plasticity, liquid limit, and gradations, particularly in the minus 200-mesh size range, indicated a comparative lack of clay minerals. Cementitious reactions between sources of alkali, such as calcium hydroxide or portland cement stack dust, and of silica, such as clay or fly ash, were found to occur in various mixes of high-bulk materials. Strengths of up to 400 psi at 84 days were observed. The possibility of emplacement of high-bulk material by both turbid flow (or density currents) below water and by mud flows above water were considered and both appear to be reasonable and possibly simpler than the current mechanisms of emplacement.
CP; Final Contract Report;
NTIS Accession No.
NTIS: PB/274-702 Available for Reference At Bureau Libraries
Dunn Geoscience Corporation