GB863805A - Removing shale particles from coal or from coal-washing effluent by froth flotation - Google Patents

Abstract

Shale is removed from effluent water, by froth flotation by a process in which the shale is rendered hydrophobic, so that the particles are lifted by the air bubbles to form a froth. The reagents used are; as depressants:-potassium permanganate, potassium dibromate, persulphates and hypochlorites. As collectors:- octyl amine, cetyl trimethyl ammonium chloride, fatty amine acetates. As collector and frother:- cetyl trimethyl ammonium bromide, cetyl dimethyl benzyl ammonium chloride, lauryl pyridinium chloride. A frothing agent e.g. methyl isobutyl carbinol is used with the collectors. The shale froth may be admixed with coal refuse or broken down flocculated and thickened and/or filtered.ALSO:Coal is cleaned, and shale is removed from effluent water, both by froth flotation by a process in which the coal is rendered hydrophilic and the shale hydrophobic, so that the latter particles are lifted by the air bubbles to form a froth. The pulp may be rewashed by rendering the middlings remaining in the pulp hydrophobic and floating them off. The coal is recovered by filtration. The reagents used are, as depressants:- potassium permanganate, potassium dibromate, persulphates and hypochlorites. As collectors:-octyl amine, cetyl trimethyl ammonium chloride and fatty amine acetates. As collector and frother:- cetyl trimethyl ammonium bromide, cetyl dimethyl benzyl ammonium chloride, lauryl pyridinium chloride. A frothing agent e.g. methyl isobutyl carbinol is used with the collectors. The shale froth may be admixed with coal refuse or broken down, flocculated and thickened and/or filtered.