REMOVAL OF INSOLUBLE SLIMES FROM POTASH ORE BY AIR-SPARGED HYDROCYCLONE FLOTATION

The presence of insoluble mineral components, typically clay minerals, in potash ores has always been a problem to the potash industry, particularly in the processing of low grade sylvinite ores. The insoluble slimes must be removed prior to potash flotation because of their high affinity for amine collectors used in the subsequent flotation of sylvite. In this regard, air-sparged hydrocyclone (ASH) flotation was examined as a process alternative for the removal of such insoluble slimes from potash ores. The effects of reagent concentration and ASH operating variables on the recovery of insolubles were studied for a typical plant feed from the Saskatchewan potash field. Results indicate that, for single stage ASH flotation, over 70% of the insolubles could be floated from a potash feed containing about 7% insolubles with salt recoveries in the underflow product exceeding 92%. These results with a 2-inch air sparged hydrocyclone suggest that high specific capacity ASH flotation, 100 times the specific capacity of conventional flotation, is a viable process alternative for the removal of insoluble slimes from potash ores.