Study on the cleanliness of super clean coal prepared by water-only cyclone

Abstract

Maintaining clean and pristine nature is the key to the use of super clean coal (SCC) for coal-based materials or energy combustion. Herein, SCC is prepared by a new water-only cyclone method, and compared the surface characteristics with the SCC products obtained by conventional chemical deashing method. The results indicate that: FTIR analysis revealed that the chemical method changed the original functional group of coal; BET analysis revealed that the SCC products prepared by the water-only method maintained the micropore volume of the raw coal and yielded a uniform and concentrated distribution of pore sizes, however, the chemical method destroying the original pore structure in the coal; SEM-EDS analysis indicated that the surface of SCC particles that were deashed using the water-only cyclone method was smooth and neat, whereas those obtained using the chemical method were seriously corroded, had a rough surface, and the SCC particles were prone to acid residues and precipitates. This study opens an innovative, simple, and clean method for the preparation of SCC, which further expands and enhances the potential application value of SCC.