Effects of pulverized coal modification on rotary triboelectric separation

Abstract

ABSTRACT Pulverized coal is separated by rotary triboelectric separation to confirm the best charger rotary speed, separation voltage, and airflow velocity. On this basis, pulverized coal surface is modified by studying four modifiers to explore the effect of pulverized coal surface modification on permittivity, specific-charge, and separation indices, including kerosene, diesel, acetic acid, and sodium stearate. Finally, separation indices of triboelectric separation are compared before and after modification. Experimental results show that kerosene has the best modification effect for pulverized coal. Under the best conditions after modification, ash deash rate is increased by 1.87%, desulfurization rate is increased by 0.44%, clean coal recovery is increased by 6.07%, and ash content is reduced by 1.95%. After the modification of pulverized coal, the specific-charge and permittivity of clean coal and gangue minerals form a greater difference, which indirectly increases the trajectory difference of different minerals in the process of rotary triboelectric separation, achieving better separation of clean coal and gangue minerals.