磷石膏反浮选提纯工艺研究

Study on purification process of phosphogypsum by reverse flotation

针对磷石膏白度低、二氧化硅含量高的问题,采用单一反浮选工艺开展了共脱除磷石膏中有机质及硅的实验研究,并对CM药剂(含功能基团有机铵类)反浮选后的磷石膏进行了形貌表征与元素分析。结果表明:在矿浆pH为1.2~6.5时,CM药剂浮选效果相差不大;与2#油相比,CM药剂反浮选净化磷石膏效果较好;在矿浆p H为3.5、CM用量为250 g/t时,石膏精矿中二水硫酸钙质量分数为91.23%,二氧化硅质量分数由7.6%下降到1.89%,精矿产率为89.53%,二水硫酸钙回收率为95.08%,精矿在45℃下干燥后白度为58%。CM药剂对磷石膏表面的硅酸盐及有机质有较好的去除效果。Zeta电位测试结果表明,CM药剂在矿浆中不仅与硅酸盐物质产生静电吸附,还会与其形成氢键,提高了药剂选择性。采用CM药剂通过单一反浮选流程取得了良好的选矿指标,为磷石膏资源化利用打下基础。

In order to solve the problem of low whiteness and the high silica content of phosphogypsum,the experimental study on removing organic matter and silicate in phosphogypsum was carried out by using single reverse flotation.SEM and EDS analysis were conducted on gypsum after reverse flotation with CM reagent(organic ammonium containing functional groups).The results showed that the flotation performances of CM reagent were not significantly different at pulp pH ranging from 1.2 to 6.5.CM reagent had better purification effect on phosphogypsum compared with 2#oil.When the pH of pulp was 3.5 and the dosage of CM reagent was 250 g/t,the calcium sulfate dihydrate content of gypsum in concentrate was 91.23%and SiO_(2) content was decreased from 7.6%to 1.89%.The yield of concentrate and the recovery of calcium sulfate dihydrate was 89.53%and 95.08%respectively.The whiteness of concentrate after drying at 45℃was 58%.CM reagent had better re-moval effect on silicate and organic matter on phosphogypsum surface.The Zeta potential test showed that CM agent not only produced electrostatic adsorption with silicate material in the pulp,but also formed hydrogen bond with it,which improved the selectivity of the agent.The use of CM reagent through a single reverse flotation process had achieved good beneficiation index,laying the foundation for phosphogypsum resource utilization.