福建某超贫磁铁矿弱磁精反浮选提铁降硅试验

福建某微细粒嵌布的超贫磁铁矿弱磁选精矿铁品位为65.30%，SiO₂含量高达8.52%，是影响精矿品质的主要因素。对弱磁选精矿试样进行了反浮选提铁降硅工艺技术条件研究。结果表明，采用1粗1精3扫、中矿顺序返回的反浮选闭路流程处理该试样，最终获得了铁品位为68.97%、回收率为98.25%、含SiO₂ 3.35%的铁精矿，尾矿铁品位仅有16.39%、回收率仅有1.75%，试验取得了显著的提铁降硅效果。

Experiments on Reverse Flotation of Concentrate of Low Intensity Magnetic Separation for Iron Increasing and Silicon Reducing of an Ultra-low-grade Magnetite in Fujian

After the ultra-low-grade magnetite of micro-fine-grained disseminated in Fujian province was separated by low intensity magnetic separation. Fe grade of the concentrate was 65.30%，while the silica content was up to 8.52%,which is the major factor affecting the concentrate quality. For the concentrate of low intensity magnetic separation，technical conditions of reverse flotation for iron increasing and silicon reducing was explored. The results indicated that through the closed-circuit reverse flotation of one roughing，one cleaning and three scavengings and middles back to the flow-sheet in turn，iron concentrate with Fe grade of 68.97%，recovery of 98.25% and silica content of 3.35% was obtained，while tailings with Fe grade of just 16.39% and recovery rate of 1.75% was gained as well. A remarkable effect of iron increasing and silicon reducing is obtained in the experiment.