Experimental study on intensified flotation of low-rank coal produced in Inner Mongolia region using highly effective collector

In order to promote high-efficiency utilization of the low-rank coal resource in Inner Mongolia Autonomous region, based on proximate, ultimate, size and densimetric analysis, a study is conducted on surface properties of the coal by X-ray diffraction and Fourier transform infrared spectroscopy examination, as well as on the effectiveness and mechanism of the high-efficiency collector through comparative flotation, contact angle and adsorption testing. As evidenced by study results, the minerals in the coal are predominately kaolinite, and on surface of the coal are different hydrophilic oxygen-containing functional groups, such as —OH, C=O, C—O, etc., plus a large amounts of fissures and pores — all unfavorable factors causing the poor flotability of the coal; with the use of the BK610 collector at a dosage of 1 kg/t, the yield and ash of flotation concentrate are 65.35% and 13.58%, respectively, a result much better than the case using the conventional collector diesel（at a dosage of 3 kg/t, the yield and ash of concentrate are 60.82% and 13.37%, respectively）; compared with the use of diesel, the use of BK610 can lead to an improved flotation efficiency with drastically reduced consumption by 66%; when BK610 and diesel are used at a respective dosage of 1 kg/t and 3 kg/t, the use of the former can give rise to larger contact angle of coal and agent adsorption rate, which are 9° and 4.75 percentage points higher than the case of using the latter, well demonstrating the efficiency of BK610 in improvement of flotation performance. The study made in the paper contributes to the development of collectors for high-efficiency flotation of low-rank coal and enhancement of the rate of utilization of such coal products in Inner Mongolia district.