低品位赤铁矿气流辅助高梯度磁选

High Gradient Magnetic Separation of Low Grade Hematite with the Air-flow

设计了一种新型高梯度磁选装置,其特点是在分选区引入上升气流以提高精矿品位。利用该装置对包钢选矿厂氧化矿弱磁选后产生的低品位(18.2%)赤铁矿进行了分选试验,结果表明,在充气量为0.16 m3/h条件下,经过粗选—磨矿—2次精选,可获得品位为48.2%,回收率为53.39%的铁精矿,与不充气相比,铁精矿品位提高3个百分点以上,回收率降低不到1个百分点。分析认为,气流能提高铁精矿品位归功于气流的搅拌作用和气泡破碎时形成的负压及强扰动。

One new type of HGMS was designed,which has a feature of introducing airflow into the separation process to increase the concentrate grade.This new device was applied to the tests on improving low grade hematite（18.2%） which were generated from oxidized ores by low intensity magnetic separation in Baosteel Dressing Plant.The results indicated that with the air flow rate of 0.16 m3/h,iron concentrate grading at 48.2% with a recovery of 53.39% was obtained by the process of roughing-grinding-two cleanings.Compared the tests without airflows,the grade of iron concentrate was increased by above 3% and its recovery decreased by less than 1%.The analysis ascribed the increase of iron concentrate grade by airflow to the air-flow agitation and the negative pressure or strong disturbance as gas bubbles broke down.