Application of a small cone hydrocyclone on high ash fine coal pre-deslimg flotation

Abstract

ABSTRACTIn this paper, pre-desliming feasibility study of a small cone angle hydrocyclone used in coal slime, which is characterized by their high ash fine fraction, was studied. Based on an analysis of particle sizes and mineral compositions from overflow and underflow under different desliming conditions, the content of the −0.045 mm fraction was 97.79%, the ash content was 51.87%, and the clay minerals were enriched in the overflow during the pre-desliming process when Φ150 mm and Φ75 mm hydrocyclones were connected in series. In both the mixed flotation feeds and the individual underflows of the Φ150 mm and Φ75 mm hydrocyclones, the clean coal yield and the combustible recovery were greatly improved compared with those of the raw coal slime under the same flotation process conditions. To further improve the clean coal yield, branch flotation experiments were carried out. The results showed that by establishing a reasonable ratio of the two types of flotation feeds with different particle sizes but similar slime properties, pre-desliming branch flotation can achieve high efficiency flotation for high ash fine fraction coal slime without coarse particles losses.