低阶煤浮选颗粒间黏附作用研究

Research on Adhesion Among Low-rank Coal Flotation Particles

由于低阶煤表面被丰富的含氧官能团覆盖且内外表面孔隙发达,因此其浮选过程药剂消耗量大。为了探究低阶煤浮选过程中不同类型矿物颗粒罩盖对其浮选行为的影响,通过激光粒度和电动电位测试手段对4种矿物颗粒及浮选精煤表面电位进行了分析。浮选试验过程中选取了石英、高岭石、蒙脱石及伊利石4种矿物。试验研究结果表明,矿物在低混入比例下,蒙脱石晶格上的正电荷在低阶煤表面产生罩盖,从而改善低阶煤浮选效果;而在中高混入比例下,4种矿物严重抑制了低阶煤的浮选精煤产率;在高混入比例下,石英砂对低阶煤浮选的抑制最为严重,主要是由于石英砂在浮选过程中的机械夹带量最大。矿物颗粒在低阶煤表面的罩盖行为对其浮选效果产生不利的影响。

Because the surface of low-rank coal is covered by abundant oxygen-containing functional groups and the pores on the inner and outer surfaces are developed, the flotation process consumes a lot of reagents. In order to explore the influence of different types of mineral particle covering on the flotation behavior of low-rank coal in flotation process, the surface potential of four kinds of mineral particles and flotation concentrate were analyzed by laser particle size and electrokinetic potential measurements. Four minerals, including quartz, kaolinite, montmorillonite and illite were selected during the flotation experiment. The experimental research results show that under the low mixing ratio, the positive charge on the montmorillonite lattice produces a cover on the surface of the low-rank coal, thereby improving the flotation recovery. While at the medium or high mixing ratio, the flotation concentrate yield of low-rank coal is severely inhibited by the four minerals, especially the inhibition effect of quarts is the most at a high mixing ratio because of the maximum mechanical entrainment in the flotation process. The covering behavior of mineral particles on the surface of low-rank coal has an adverse effect on its flotation response.