Apatite Enrichment from Iron Ore Tailings by Rotary Triboelectrostatic Separator

This is an article in the field of mineral processing engineering. Many iron ore tailings in China contain precious phosphorite resources, such as apatite, but there is a lack of economic and effective separation methods to separate and utilize them. The rotary triboelectric separation (RTS) technique has the advantages of low environmental pollution and energy consumption without the usage of water and reagents. This paper emphatically investigated the effect of different friction materials including copper, stainless steel, aluminum and PVC (polyvinyl chloride) on the charging characteristics of pure minerals of apatite, quartz, or thoclase and ilmenite which were the main components of iron ore tailings. The variation of apatite separation and enrichment performance in Shenjia iron tailings with the primary rotary triboelectrostatic separation parameters was studied and the optimum conditions were determined. It was concluded that apatite rubbed with PVC showed the greatest difference in the charge-mass ratio with other minerals. In the actual subsequent tests of apatite from iron ore tailings, a reasonably good separation performance with an apatite concentrate of 27.6% P₂O₅ grade at 49.3% P₂O₅ recovery was obtained under the conditions of rotary charger rotation speed 5000 r/min, feed rate 50 g/min, co-flow airvelocity 0.5 m/s, feed flow air velocity 0.6 m/s, accomplishing the effective separation and purification of apatite in iron tailings.