某低品位难选菱铁矿磁化焙烧-磁选试验研究

对新疆某低品位菱铁矿矿石进行了提铁降杂试验研究。采用磁化焙烧-阶段磨矿-阶段磁选工艺，在焙烧温度800 ℃、焙烧时间45 min、一段磨矿细度-0.075 mm粒级占55.00%、一段弱磁选场强0.15 T、二段磨矿细度-0.075 mm粒级占91.60%、二段弱磁粗选场强0.12 T、二段弱磁精选场强0.12 T条件下，可获得产率49.32%、TFe品位63.02%、铁回收率91.36%的铁精矿，铁精矿中SiO₂、Al₂O₃、S和P杂质含量低，符合磁铁精矿C63级别质量要求。

Experimental Study on Magnetizing Roasting and Magnetic Separation of Refractory Lean Siderite Ore

The beneficiation technique to upgrade the iron concentrate of a low-grade siderite ore from Xinjiang was investigated and a flowsheet consisting of magnetizing roasting, staged-grinding and staged-magnetic separation was proposed. An iron concentrate with a yield of 49.32% can be collected at TFe grade of 63.02% and recovery of 91.36%, for which the processing parameters are as follows: roasting temperature of 800 ℃, roasting time of 45 min, a grinding fineness of -0.075 mm 55.00% for the first stage and -0.075 mm 91.60% for the second stage of grinding, and the magnetic field strength of 0.15 T, 0.12 T and 0.12 T, respectively for the first low intensity magnetic separation (LIMS), the second roughing and the second cleaning of LIMS. It is shown that the obtained iron concentrate containing low content of SiO₂, Al₂O₃, S and P impurities, completely meets the quality requirements for C63 grade of magnetite concentrate.