Powder Technology, Vol.367, 568-575, 2020
A novel and low cost coal separation process: Combination of deep screening classification and gravity separation
A separation process for power coal is proposed here, with the aim of mitigating some of the technical difficulties encountered in the full-size washing and upgrading. To this end, the characteristics of both a 3 mm flip-flow screen and a dense-medium separator were thoroughly investigated. The results showed that reasonable adjustment of the working frequency and tension can significantly improve the 3 mm flip-flow screening effect. The screening efficiency was found to reach as high as 81.77%, and the undersize fraction was reduced to only 2%. For the dense-medium separator, it was found that the ash segregation after separation was mainly affected by the feeding position, the ratio of horizontal flow to upwelling flow, and feeding rate, in that order. The maximum ash segregation was found to be 0.746 at a 15 cm feeding position, a horizontal flow to upwelling flow ration of 2.75, and a feeding rate of 27.5 kg/min. (C) 2020 Published by Elsevier B.V.