Study of Mechanical Force on Coal Gangue Reactivity

Abstract

The property of raw kaolinite-coal-gangue is very stable, and reactivity of kaolinite-coal-gangue is enhanced by mechanical force. The SEM, XRD and IR were used to analyze mechanochemical changes during kaolinite-type-coal gangue grinding. The results showed that mechanical force plays a dominant role in the enhanced reactivity, by inducing dehydration reactions the lattice OH grouping decreased with the extension of grinding time. The separation of tetrahedral and octahedral layers combined with the increasing disorder of the kaolinite crystal structure, resulting in kaolinite-type-coal gangue particles become "loose" aggregates. Moreover, due to destroy to tight Si-O and Al-O bond, the mechanical force increases the solubility of SiO2 and Al2O3, which enhanced the reactivity of coal gangue.