Effect of chemical conditioning on the triboelectrification of coal and mineral particles

Chemical conditioning was used to modify the triboelectrification of coal and mineral particles. The chemicals tested included starch, lignin, kerosene, ethanol, acetic acid, salicylic acid, sodium oleate, Sodium Hexametaphosphate (SH), sodium silicate, Sodium Dodecylbenzenesulfonate (SDBS), Sodium Bicarbonate (SB) and ammonia. A high-speed, dry mixing method was employed. The charge-to-mass ratio of the coal and mineral samples, both untreated and treated, was tested using a Faraday cup. Dielectric constants were determined by measuring capacitance. It is found that the selectivity of the additives toward coal or minerals is not consistent. Salicylic acid is the optimal additive to enhance the triboelectrification performance of coal samples. Starch, lignin and sodium oleate are suitable for removal of pyrite. SH, sodium silicate, SDBS, SB and ammonia are suitable additives for the removal of ash-forming minerals.