Effect of cone angle on separation characteristics of compound water-only cyclone

Abstract

Experiments have been conducted on a 76-mm water-only cyclone treating coal below 2 mm size having different proportion of −0.075 mm fines. The effect of cone angle of the cyclone (compound cone) has been analyzed on water split, separation of −0.075 mm fines, separation of coarse solids, and on separation behavior of individual size fractions of the feed. It has been noted from the results that there exists a linear relationship between the flow rate of water in the feed and flow rate of water reporting to overflow stream. This relationship is independent of the cone angle and, with changes in the fines content in the feed, only the intercept of the straight varies, keeping the slope constant. Further, it has also been found that the percentage of fines below 0.075 mm reporting to the overflow is directly proportional to the percentage of feed water reporting to the overflow. This relationship is found to be independent of the cone angle and the fines in the feed. The performance of the water-only cyclone has been analyzed by plotting partition curves for different experimental conditions. In addition to this, the Rosin-Rammler equation has been fitted to the partition curves of the bulk feed and individual size-fractions. The analysis of the results has revealed that the specific gravity of separation increases with increase in the cone angle of the cyclone while it decreases with increase in percent fines present in the feed. Mathematical relationships have been developed to relate the variation in SG50 with cone angle and percent fines in the feed.