DENSE-MEDIUM SEPARATION OF HEAVY-METAL PARTICLES FROM SOIL USING A WIDE-ANGLE HYDROCYCLONE

Wide-angle hydrocyclone tests were conducted to separate fine (-150 mu m) particles based on differences in particle density. Mixtures of fe rrosilicon (FeSi) and quartz or lead and soil of similar size ranges w ere separated in a 25.4 mm diameter hydrocyclone under various test co nditions. Separations were made in dense-medium suspensions of fine ma gnetite and water to improve the overall separation efficiency compare d to water-only separations. For the FeSi/quartz mixture, when the sus pension relative density was raised to 1.4, FeSi recoveries exceeding 89% with quartz recoveries over 90% were obtained in a single pass thr ough the hydrocyclone. For the lead/soil mixture, lead recoveries exce eding 97% with soil recoveries over 95% were possible at a suspension relative density of 1.3.