Application Of Depressores Of Calcium And Magnesium Minerals For Phosphate Ore Flotation

The selection of middle and low grade phosphorus and high grade magnesium phosphate ore has been a major problem in the flotation of phosphate ore..The gangue mineral of phosphate ore is generally composed of silicate and carbonate mineral,phosphorous ore is collophanite.In general,the direct and reverse flotation process is used in flotation of the phosphate ore,meanwhile the floatability of carbonate minerals and phosphorous ores are similar and hardly to be separated.Therefore,explore effective depressores for carbonate minerals is key to solve the kind of ore flotation problem.According to the subject,in the paper,two depressores of carbonate were synthesized and applied to the flotation test for three mid-low grade phosphate ore,and good flotation results were got.Main contents of the thesis were as follows:(1)Calcium and magnesium minerals depressor called YS-1 was synthesized with melamine as raw material,while additive and synergistic agent were added.YS-1was applied to the flotation test for DayuKou phosphate ore.A good flotation result,that the concentrate grade of P2O5 was 29.63%,the recovery of P2O5 was 58.84%,the content of MgO was 0.87%.and the removal rate of MgO was 94.86%.The result showed that YS-1 can be used as a depressor of calcium and magnesium minerals depressor for phosphate ore positive flotation.A fraction of concentrate was sent to the reverse flotation,which can improve the beneficiation indexes,save reagents and the cost of the reverse flotation process.(2)Another depressor of calcium and magnesium minerals called YG was prepared by chemical modification with lignin sulfonate.The technics of synthesis process and factors that affect its property were investigated by the performance in the flotation test for silicon-calcium-high magnesium collophanite in Hubei.The optimum synthesis process is as follows: hydrogen peroxide was the oxidant while the dosage was 15%,the oxidation temperature was 90 ? and oxidation time was 2h,formaldehyde dosage is 20%,sodium sulfite as sulfonating agent,dosage of sulfonating agent was 30%,sulfonation temperature was 90?,sulfonation time was2 h.(3)YG as depressor of calcium and magnesium minerals was applied to the flotation test for Fangmsshan phosphate ore.Compared to the depressor Y-FMS which is the present depressor in the flotation,YG had better performance.The best flotation process and conditions were determined through the exploration and optimization.The optimum dosage was determined by orthogonal experiment.By a direct and reverse flotation process,the concentrate grade of P2O5 was 29.54%,the recovery of P2O5 was 64.31%,the content of MgO was 0.83%.and the removal rate of MgO was 95.42%.