An evaluation of the role of particle size in the flotation of coal using different cell technologies

Abstract

A large variety of new flotation cells has been introduced in the last few years, probably as a result of the successful introduction of column flotation in the minerals processing industry. In common with the column cell, a number of these new cells employ an essentially quiescent separation zone. However, a number of novel cell designs have been introduced that use agitation mechanisms similar to those employed on conventional flotation cells. The aim of this investigation was to evaluate flotation behaviour in both an agitated and non-agitated environment, particularly with respect to particle size. A hybrid ‘agitated’ column cell was designed for the investigation, and the operation of this unit was compared to that of a column cell, and to a batch flotation cell, on a laboratory scale. The testwork was conducted on coal fines, as problems with the flotation of coarse coal particles in a column cell had previously been identified. It was demonstrated that the addition of an agitated stage to a column cell can significantly improve the coarse particle recovery in comparison to the conventional column cell, while maintaining good selectivity in the fine sizes.