New Techniques in Processing Tungsten Ore Slimes

摘要

New methods of beneficiation of wolframite ore slimes in China are described. A relatively high level of metal recovery has been maintained by the separate treatment of all plant slimes. Satisfactory results were gained with a centrifugal separator, a newly developed wet high-intensity magnetic separator and with wolframite flotation (phosphonic or arsonic acids as collector). Two process routes recently introduced for wolframite ore slime treatment are presented - centrifugal separation followed by flotation and wet high-intensity magnetic separation followed by flotation. The former process, introduced at one mine to treat slimes with 0.302% WO3, attained a recovery of 62.92% WO3 with a concentrate grade of 61.15% WO3. Another mine used the latter process to treat slimes of 0.422% WO3, a concentrate grade of about 50% WO3 being produced with a recovery of 73.84%. In China more than 10,000,000 tons of tungsten ore is treated in several dozen mills annually. Generally, the slimes account for 11-15% by weight of mill feed, corresponding to a metal distribution of 15-20%. Much attention has been paid to improvement of slime beneficiation by research and development. Significant results were obtained by the application of new techniques and process improvements at the different mines. At present the recovery of wolframite from slimes reaches 40-50%, on average - a level that is difficult to attain by any conventional means.