Experimental study on magnesium removal in fluidized bed flotation of coarse phosphate rock

Phosphate rock is one of the important non-metallic mineral resources, and magnesium removal is essential for its efficient utilization. The magnesium removal of coarse phosphate rock has the advantages of reducing energy consumption and subsequent flotation pressure, but the current flotation magnesium removal methods still mainly focus on fine particle size. In this study, the effect of Fluidized bed flotation (FBF) on the reverse flotation for magnesium removal of coarse phosphate rock was investigated by combining the separation test and SEM-EDS analysis to underflow (-300+74 μm, P2O5 grade 27.20%, MgO grade 3.81%) from the mill of a phosphate concentrator in Yunnan Province. The results show that FBF has the effect of magnesium removal of coarse phosphate rock, and the concentrate yield is 43.63%, P2O5 grade is 31.72%, and MgO grade is 1.68% under the optimal collector dosage of 500 g?t-1. The feed particle size has a great influence on the removal effect of MgO. The MgO grades of -300+250 μm, -250+125 μm and -125+74 μm in concentrate are 3.032%, 1.318% and 1.031%, and the MgO removal rates are 46.74%, 77.62% and 94.04%. According to the test results, a new process of FBF pre-separation of coarse concentrate and FBF tailing re-grinding and re-separation is proposed, and the MgO grade and P2O5 recovery of coarse concentrate can be adjusted by the feed particle size, and the coarse concentrate and flotation machine concentrate are blended into the final concentrate. This study provides technical support for the flotation magnesium removal of coarse phosphate rock.