Effective decarbonization of coal-series kaolin by triboelectric separation based on different motion behaviors of charged particles in electrostatic field

Abstract

In this work, a rotary triboelectric separation system was set up to study the motion characteristics of charged particles (i.e., kaolinite and coal) using Comsol software simulation and high-speed camera tracking. The results showed that the negatively charged kaolinite particles moved toward the positive electrode, while the positively charged coal particles moved toward the negative electrode. Meanwhile, in horizontal displacement increased with the increase of the charge-to-mass ratio of kaolinite and coal, which favored the decarbonization of coal-series kaolin. Therefore, the effective decarbonization of series-coal kaolin with different particle sizes was achieved via rotary triboelectric separation, in which the decarbonization efficiencies for 0.25–0.50 mm, 0.125–0.25 mm, and 0.074–0.125 mm coal-series kaolin were 41.86%, 45.38%, and 42.66%, respectively. This indicates that the efficient purification and upgrading of coal-series kaolin can be realized via rotary triboelectric separation.