Recent developments in techniques and methodologies for improving thickener performance

Research projects directed towards 'Improving Thickener Technology' have been conducted by the Al Parker Cooperative Research Centre for Hydrometallurgy since 1988 through the Australian Mineral Industries Research Association with support from 25 Australian and international mineral processing companies. These projects have resulted in the development of a range of research tools and techniques to address flocculation and thickening issues. Laboratory and plant studies have focused on how key factors, such as mixing intensity, mixing duration and solids concentration, affect flocculation efficiency and, hence, thickener performance. A comprehensive computational fluid dynamics (CFD) model has been developed to predict likely full-scale performance under various process conditions, based upon a knowledge of thickener design, plant flows and laboratory assessment of the flocculation behaviour of the feed slurry. Application of this CFD model to problems within specific mineral processing operations has resulted in significant benefits, in one case leading to doubling of a thickener's throughput. This paper presents an overview of the work conducted during these projects, focusing on the research tools, the nature of the information that has been gained and the implications for thickener performance. Brief details will be presented on research issues currently being investigated. (C) 2000 Elsevier Science B.V. All rights reserved.