Fundamental study for improvement of dewatering of fine coal/refuse. Semi-annual report, November 1981-April 1982

The objectives of this research program are to formulate models for predicting the efficiency of mechanical dewatering, the rate of dewatering and the residual moisture content of dewatered coal/refuse and to suggest improved mechanical dewatering methods. To achieve these objectives, the following tasks are being carried out: (1) characterization of fine coal particles and filter cakes; (2) theoretical models for fine coal dewatering, (3) experimental measurement of dewatering; and (4) enhanced dewatering methods. Some highlights for this reporting period are: (1) important improvements in the micrographic analysis of coal filter cakes were achieved, (2) refinement of the model to predict the one-phase flow rate and permeability for the coal cake was initiated; (3) controlled filtration and dewatering experiments were carried out with different size fractions of the -32 mesh Pittsburgh seam-Bruceton mine coal; (4) filtration and dewatering experiments with five surfactants were completed; and (5) data analysis shows a strong correlation for the adsorption isotherm of all five surfactants with the reduction in moisture content. 6 references, 31 figures, 7 tables.