Full-process high-efficiency separation practice of refractory coking coal in Pingdingshan mining area

In order to solve the problems of low efficiency of refractory coal in Pingdingshan mining area and difficulty in synergistic improvement of clean coal yield and quality, the core physical characteristics were systematically revealed by means of petrographic analysis, element detection and argillization test, and a three-stage process system of "source coal blending-middle re-separation-end quality improvement" was constructed. Combined with the upgrading of TDS intelligent dry separation equipment and the innovation of flotation intelligent control technology, the research was carried out. The core difficulty of refractory coal in Pingdingshan mining area is that the density of vitrinite and inertinite overlaps, and the difference of components leads to inconsistent density response and strong argillization characteristics. Therefore, the source coal blending in the process system is the key to improve the quality of the selected coal. By studying the 8 kinds of washability grade ratio in the raw coal of the group and the 5 kinds of cross-combination ratio test between the Dingwu group (high internal ash extremely refractory coal) and the group 's easy coal preparation, it is found that the higher the proportion of easy coal preparation, the higher the yield of mixed coal clean coal and the better "yield-ash" balance; the high ash clean coal with a recoverable ash content of 12.90% in the middlings re-separation system; three-stage flotation of coal slime reduced the slime yield from 12.13% to 6.40%. The coal-carrying rate of gangue and the coal-carrying rate of gangue in TDS intelligent dry separator are controlled at 1%-3%.