The New Technology of Separation of Coal Concentrates from Centrifugal Filtrate

Abstract

The effluents from centrifuges for dewatering flotation concentrates of coking coals give often a significant problem in the silm-water circuit, due to the release of dense black floating foam on the surface of the water in Dorr thickeners. For the purification of the centrifuge effluents, selected flocculants were used. Significant amounts of leachate is not dewatered but only mixed with flotation waste and deposited in waste settling tanks. Carried out studies show that the solid phase in the effluent consists of hydrophobic coal grains and hydrophilic grains of minerals. Through the use of selective sedimentation, allowing separate hydrophilic grains (bottom layer), a high quality carbon concentrate (upper layer, hydrophobic grains) is obtained. The process of selective sedimentation can be significantly accelerated and enhanced by the addition of hydrophobic reactants to the effluent. On the basis of conducted tests and trials, a pilot installation for the production of coal concentrates from industrial effluents from centrifuges was developed. The developed technology allows to obtain coal concentrates with low ash and water content as well as high energy parameters.