Understanding the Thickening Process

Abstract

The thickening process is the primary method of producing high solids slurries for the minerals industry. Thickener outputs can accommodate a range of tailings disposal options from low yield stress, easily pumped suspensions for disposal in conventional ‘wet’ tailings dams to more concentrated slurries for delivery to ‘dry disposal’ and backfill applications. The thickening process, although operated successfully in a large range of sites around the world, is poorly understood and predictive design of thickening devices is still empirical. Although predictive models of thickening do exist, the correlation to reality is often poor and there is a desperate need to bring the two together to make rational improvements to thickener design and operation. Therefore, whilst some would dismiss the models as being unacceptable for predictive design, they are very useful in formulating expected operational trends and providing an understanding of the directions one should take in improving operational performance. The aim of this article is to bring together model, laboratory and in-field results to elucidate the state of the art in understanding thickener operation from first principles.