国外某低品位微细粒磁铁矿石选矿工艺研究

摘要

国外某铁矿石铁品位为31．92%、SiO2含量为46．44%，矿石矿物嵌布粒度微细。为探索在较粗磨矿细度条件下获得高质量铁精矿的高效选矿工艺，对其进行了选矿流程试验。实验室试验结果表明：采用阶段磨矿—弱磁选—磁选柱分选工艺，当磨矿细度达到-0．043 mm占95%时，才能获得铁品位大于68%、硅含量小于5%的高质量铁精矿；而采用阶段磨矿—弱磁选—反浮选工艺，当磨矿细度放粗至-0．076 mm 占90%时，即可获得铁品位大于68%、硅含量小于5%的铁精矿，且可减少三段磨矿量45%以上。扩大连续试验结果表明，原矿经两段阶段磨矿(-0．076 mm占90%)—弱磁选—反浮选—反浮选尾矿脱水后再磨(-0．038 mm占95%)再选流程选别，可获得精矿铁品位68．12%、SiO2含量4．59%、铁回收率70．02%、磁性铁回收率96．83%的指标，实现了该矿石的高效分选。%There is an iron ore contains 31. 92% iron and 46. 44% SiO2 from abroad. Mineral dissemination of the ore is microfine. Beneficiation test was conducted in order to provide a high efficiency beneficiation process by which qualified iron concentrate can be obtained while in the coarser grinding conditions. The results of small-scale beneficiation test showed that i-ron concentrate with iron grade above 68% at the grinding fineness of 95% passing 0. 043 mm by adopting the process of stage grinding-LIMS-column separator separation,but iron concentrate with iron grade above 68% at the grinding fineness of 90%passing 0. 076 mm by adopting the process of stage grinding-LIMS-reverse flotation,moreover can reduce above 45% ore quan-tity for the third grinding. The results of the pilot-scale test showed that iron concentrate with iron grade of 68. 12%,content of 4. 59%,iron recovery of 70. 02%,magnetic iron recovery of 96. 83% can be obtained via two stages grinding(90% passing 0. 076 mm)-LIMS-reverse flotation-dehydration and regrinding(95% passing 0. 038 mm) for flotation tailings-LIMS-reverse flotation process. High efficient separation was achieved on the ore.