laboratory electrostatic separator at the laboratories of
Cable Sands ( WA) Pty Ltd. The material used was heavy mineral concentrate from two di erent deposits ( A and B) at Cable Sands. Sample B was more heavily coated than A. The changes in separation after sonica- tion with water and sodium carbonate, as well as a more detailed description of the tests, were previously reported [ 4]. The best improvement was for treatment with
Na2CO3 as predicted from the conductivity tests. Improvement in separation of up to 20in purity
(grade) and 12in recovery of TiO2 in the conductor stream and 7and 12respectively for ZrO2 in the non-conductors were achieved for sample B. Sample A,
being less heavily coated to start with, did not improve as much (2and 16for TiO2 and 10and 1for
ZrO2). However, because the process is repeated over
many stages of electrostatic separation in the plant, it
will have a much greater overall e ect.