Intensifying the attrition of mineral waste in stirrer mills

Up to now, contaminated mineral residues-especially in the particle size range <100 mum-cannot be cleaned effectively by mechanical treatment. Therefore, a new process has been developed by modifying well-known comminution techniques in stirrer mills. Various lab-scale tests have been carried out using mineral oil-contaminated quartz sand fraction as testing material. The cleaning efficiency, which could be obtained using the high-performance attrition process, was considered much better as compared to conventional attrition technologies in every case. The attrition process, now in industrial scale, has been tested by combining grinding attrition, classification and dosing processes, with an integrated dedicated measurement and control system. The resulting high-performance attrition pros ensures a constant solids-concentration, which is essential for high-attrition efficiency. (C) 2004 Elsevier B.V. All rights reserved.