针对中低品位磷矿无法直接加工的问题及云南晋宁磷矿的组成特点,使用YP系列捕收剂对原矿进行正浮选脱硅,再利用浓缩湿法磷酸和硝酸对脱硅后的磷矿进行脱镁处理。正交实验结果表明,以硝酸为预处理剂时,液固质量比为4、pH为2.5、温度为60 ℃、反应时间为4 h是最佳的脱镁条件,此条件下精矿镁磷比（氧化镁与五氧化二磷质量分数之比）为2.16%,磷损失率为1.7%;以湿法磷酸为预处理剂时,pH为2.5、液固质量比为3、反应时间为2 h、温度为50 ℃是最佳的脱镁条件,此条件下精矿镁磷比为3.32%,磷损失率为0.3%。同时对实验数据进行拟合分析,得到了干基镁磷比核心指标变化的动力学模型。该研究为有效利用高硅型中低品位磷矿提供了新的思路和参考。

In view of the problem that middle-low grade phosphate ore can not be directly processed and the composition charac-teristics of Jinning phosphate ore in Yunnan Province,YP collectors were used to desilicate the raw ore by positive flotation,and then concentrated wet-process phosphoric acid and nitric acid were used to magnisium removal of the phosphate ore after desilication.The orthogonal experiment results showed that when nitric acid was used as pretreatment agent,the optimum conditions for magnesium removal were liquid-solid ratio of 4,pH of 2.5,temperature of 60 ℃,and reaction time of 4 h.Under these conditions,magnesium-phosphorus ratio（Mass fraction ratio of MgO to P₂O₅） of concentrate was 2.16% and phosphorus loss rate was 1.7%.When wet-process phosphoric acid was used as pretreatment agent,the optimum conditions for magnesium removal were pH of 2.5,liquid-solid mass ratio of 3,reaction time of 2 h and temperature of 50 ℃.The magnesium-phosphorus ratio of concentrate was 3.32%,and the phosphorus loss rate was 0.3%.At the same time,the experimental data were fitted and analyzed,and the dynamic model of the core index of dry magnesium-phosphorus ratio was obtained.The study provided a new idea and reference value for the effective utilization of high silicon middle-low grade phosphate rock in China.