Effect of a cyclonic flotation column on the separation of magnesium from phosphate ore

This study was performed to investigate the effects of the cyclonic separation mechanism on the removal of magnesium from phosphate ore. An analysis of the particle-bubble collision mechanism in a cyclonic force field was used to design two different pulp circulation systems for a cyclonic-static micro-bubble flotation column (FCSMC). Experiments comparing the two conditions were then conducted. Size analysis of the feed and separated products was conducted with a BXF cyclone size analyzer. The results show that about 34.60% of the total MgO content in the feed exists in the −10 μm fraction. This demonstrates that magnesium removal from phosphate ore has the characteristics of a micro-fine particle flotation problem. Under conditions of cyclonic circulation the MgO level of the concentrate is 1.74%, which is lower than that obtained from the column operated in direct-flow circulation by 0.34%. These results indicate that the cyclonic circulation mechanism of the FCSMC can promote removal of micro-fine particles containing magnesium. This is attributed to the function of surface flotation and to the reduction of the lower separation limit under conditions of cyclonic circulation.