Energy Sources Part A-recovery Utilization and Environmental Effects, Vol.32, No.19, 1801-1811, 2010
Coal Floatability Characterization by Film Flotation
This study covers film flotation data conducted on a bituminous coal of -850 + 425 m, -425 + 300 m, -300 + 212 m, -212 + 150 m, and -150 + 63 m size fractions. Separation medium was prepared at various methanol-water mixtures to give different surface tensions. The float and sink fractions obtained by the tests were subjected to ash analyses. Calculated contact angle values were related with weight distribution and ash contents of floats. A contact angle distribution was observed in all size fractions. Inorganic materials were observed to be placed usually in vitrinite group macerals. It was concluded that distribution of contact angle resulted mostly from the distribution of organic constituents (maceral groups) within particles and selective breakage occurred during the comminution. The highest value of contact angle, 77.03 degrees, was determined for -850 + 425 m and the lowest one, 67.82 degrees, was determined for -150 + 63 m size fraction where some degree of inorganic liberation and/or selective accumulation was obtained.