煤泥浮选过程强化之三——低阶/氧化煤浮选界面强化篇

Fine coal flotation process intensification-part Ⅲ:interface intensification of low-rank and oxidized coal

低阶/氧化煤由于其表面孔隙发达、含氧官能团多,导致浮选捕收剂消耗量极大、效率低下,而界面强化是提高其分选效率的重要途径。从低阶/氧化煤表面含氧官能团与捕收剂的相互作用出发,开发一种新型的极性复配捕收剂,探索了极性复配捕收剂和孔隙机械压缩对低阶/氧化煤浮选界面强化的影响,并进行了浮选动力学试验验证;借助机械热压机对难浮煤进行处理,采用XPS光电子能谱、压汞仪及比表面积测试仪(BET)和红外光谱仪检测热压前后褐煤表面性质的变化,并运用Van Oss-Chaudhury-Good理论计算了煤样的表面自由能,探明了机械热压对褐煤表面物理化学结构的影响。机械热压过程对褐煤表面疏水性改善及浮选界面强化具有一定的借鉴意义。

The flotation of low-rank/oxidized coal is low in efficiency and high in consumption of collector because of the presence of a large quantity of well-developed voids and functional groups on surface of such coal. It is found that interface intensification is an important way for the improvement of flotation performance in this instance. Following an introduction to a new kind of polar complex collector developed based on analysis of interaction between the oxygen-containing functional groups and collector,a study is made in the paper of the effect on enhancement of flotation interface of low-rank/oxidized coal produced by polar compound collector and mechanical compression of surface voids. The work made covers： verification of test result through thermodynamic analysis; treatment of difficult-to-float coal through mechanical thermal compression using mechanical thermos compressor; detection of the change of surface property before and after mechanical thermos compression treatment using X-ray photoelectron spectroscopy（ XPS）,mercury intrusion porosimetry,specific surface area meter and Fourier transform infrared spectroscopy; and calculation of surface free energy of coal sample using Van Oss-Chaudhury Good theory. Through the studies made,the effect of mechanical thermos compression on surface physico-chemical structure of lignite has been brought to light. The research-derived achievements may serve as a reference for better understanding of the effect of mechanical thermos compression process on improvement of hydrophobicity and interface intensification of lignite.