Comparative study of conventional cell and cyclonic microbubble flotation column for upgrading a difficult-to-float Chinese coking coal using statistical evaluation

Abstract

ABSTRACTInvestigations were executed to upgrade a difficult-to-float coking slime (38.40°Contact angle and 40.14% ash content) by conventional flotation cell and cyclonic microbubble flotation column technologies. Firstly, flotation performance of conventional cell considering interactions of collector dosage, pulp density, and frother dosage was estimated by statistical evaluation. The conventional cell results indicated that clean coal with 11.89% ash content was obtained at 53.94% yield and 79.40% combustible recovery. Secondly, the effects of controlling factors (froth depth and circulating pulp pressure) on the flotation performance of cyclonic microbubble flotation column technology (FCMC) were investigated according to the earlier conventional cell studies. The combustible recovery of the clean coal could be further increased to 90.54% at 62.78% yield and 11.67% ash content by using the FCMC. Finally, the flotation performance in the conventional flotation cell and FCMC was compared with that of the release analysis data. It was concluded that, in general, the performance of the conventional flotation cell was poorer, while the flotation performance of the FCMC was better than that of the release analysis data. Therefore, this difficult-to-float coking coal can be concentrated to a qualified product with minimal usage of reagent and low cost by using the cyclonic microbubble flotation column technology.