Dry separation of brown coal fly ash, determination of its physical, morphological, chemical, and mechanical properties of its cementitious mixes

Abstract

The dry separation of brown coal fly ash was carried out in this research using ultrafine air classifier. Classifiers wheel speed was increased from 2000 to 10000 rpm to obtain fine and coarse products. As the speed of classifier was increased diameter of particles decreased and particle morphology was observed on optical, electron microscopes which showed that at 10000 rpm classifiers wheel speed, average fine particles morphology changed from angular and rounded irregular slaggy particles to spherical particles. High volume cementitious mixes were prepared with fine and coarse products in which cement -60% fine products samples showed a considerable increase of compressive strength as compared to cementitious raw fly ash control samples.