正反浮选富集低品位微细粒级重介质分选磷尾矿

Concentration of fine-grained and low-grade collophanite from gravity tailings of phosphate by direct-reverse flotation

为了富集宜昌磷矿重介质分选产生的低品位微细粒级磷尾矿,对其进行了多元素分析及粒度分析,-0.038mm粒级质量分数达到80%以上,原矿品位P2O5为14.23%,MgO质量分数为4.44%,SiO_2质量分数为28.11%,因此该磷矿属于微细粒级硅钙质低品位磷矿。试验考察了浮选矿浆质量分数、搅拌强度、药剂制度、浮选流程对浮选指标的影响。结果表明,在浮选矿浆质量分数为24%,搅拌转速为2000r/min时,经过常温正浮选1次粗选2次精选1次扫选,反浮选1次粗选1次扫选,中矿顺序返回闭路流程试验,得到了磷精矿P_2O_5品位28.07%、回收率83.20%的浮选结果;正浮选尾矿品位降至5.28%,反浮选尾矿品位降至1.34%。有效回收了宜昌磷矿重介质分选产生的低品位微细粒级胶磷矿,减少了资源损失。

The multi-element and particle size analyses were made to concentrate the fine-grained and low-grade collophanite from gravity tailings of phosphate by the direct-reverse flotation. With the size fraction of 0. 038 mm up to above 80%, the content of P2O5 14.23%, the content of MgO 4.44% and the content of SiO2 28. 11%, the phosphate rock was a fine-grained siliceous and calcareous low grade phosphate rock. The effects of flotation concentration, stirring strength, reagent regime and flotation process on the flotation index were investigated. The results showed that with the flotation slurry concentration of 24% and the stirring intensity of 2 000 r/min, the phosphate concentrate with the grade of P2O5 28.07% and the recovery rate 83.20% could be obtained in a closed-circuit process test with the positive flotation of one-roughing, two-cleaning and one-scavenging and the reverse flotation of one-roughing and one-scavenging and mid- dlings sequential return at room temperature. The grade for the positive flotation railings was reduced to 5.28% and the grade for the reverse flotation railings dropped to 1. 34%. This indicates that the low-grade fine-grained phosphate rock produced by the heavy media separation of Yichang phosphate rock can effectively lower the loss rate of Yichang phosphate rock resources.