某磁铁矿磨前湿式预选抛尾工艺试验

Test on Wet Pre-Selection Discarding Tailings Process of a Magnetite Ore before Grinding

湖北某选厂为了减少入磨矿石量,提高入磨矿铁品位,采用预先筛分—高压辊磨—检查筛分—湿式粗粒磁选预选工艺进行抛尾,预选精矿通过阶段磨矿—阶段磁选—淘洗流程进行分选。试验结果表明:将试样细碎至-3 mm时,抛尾产率为31.41%,预选尾矿全铁品位为7.31%,磁性铁品位为0.67%,预选精矿全铁品位为52.46%,磁性铁品位为49.28%,磁性铁回收率为99.38%;在最终磨矿细度为-0.074 mm90%时,可获得全铁品位为68.12%、硫品位为0.265%、全铁回收率为85.76%的铁精矿;该工艺减少了高压辊磨机的循环负荷,同时抛尾效果明显,获得了较好的铁精矿指标。

In order to reduce the amount of ore into grinding and improve the grade of iron into grind⁃ing,a concentrator in Hubei Province adopts the pre-screening-highpressure roller mill-check screening wet coarsegrained magnetic separation pre-concentration process to discard the tailings,and the pre-con⁃centration concentrate is separated by stage grinding-stage magnetic separation-elutriation process.The test results show that when the sample is finely crushed to-3 mm,the tailings discardingyield is 31.41%,the to⁃tal iron grade of the pre-concentration tailings is 7.31%,the magnetic iron grade is 0.67%,the total iron grade of the pre-concentration concentrate is 52.46%,the magnetic iron grade is 49.28%,and the magnetic iron recovery rate is 99.38%.When the final grinding fineness is-0.074 mm 90%,the iron concentrate with total iron grade of 68.12%,sulfur grade of 0.265%and total iron recovery of 85.76%can be obtained.The process reduces the circulating load of the high-pressure roller mill,and the tailings discarding effect is ob⁃vious,and a better iron concentrate index is obtained.