Research on 1mm desliming before separation and high-efficiency separation to improve quality for steam coal

Abstract

ABSTRACT For the established steam coal preparation plant that uses dense-medium shallow groove separation process, reducing the separation lower limit is conducive to improving its economic benefits. Reducing the lower limit to be consistent with the mesh size of the demedium screen, which is 1 mm, so that more coal can be separated without affecting the normal operation of the entire system. A process of 1 mm desliming before separation and dense-medium shallow groove separation was proposed in this paper. The kinematic characteristics and desliming performance of rigid screen surface and elastic screen surface were compared and analyzed. The separation performance of each size coal in the dense-medium shallow groove separator was investigated and the ratio of upward medium flow and horizontal medium flow was optimized. The industrial experiment results showed that the screening efficiency and desliming efficiency of elastic screen surface were increased by 4.31% and 4.37% respectively compared with rigid screen surface. The separation performance of each particle size coal in the dense-medium shallow groove separator became worse with the decrease of particle size. When the ratio of upward medium flow and horizontal medium flow was 8:2, the separation performance of 200–1 mm size coal was the best, and its probable error was 0.04 g/cm3. The optimized process could significantly decrease the slime content in separation system and improve clean coal yield.