某微细粒嵌布铁矿石磁选—絮凝脱泥—反浮选试验

湖南某铁矿石中铁矿物以磁铁矿为主,赤铁矿次之,并有12.12%的铁以硅酸盐矿物形式存在。其中磁铁矿属中细粒嵌布,但赤铁矿具典型极微细粒嵌布特征,分选难度极大。根据矿石性质,采用阶段磨矿—弱磁选—强磁选—选择性絮凝脱泥—反浮选工艺进行选矿试验,即第1步在-0.075 mm占65.87%的较粗磨矿细度下通过弱磁选选出磁铁矿,第2步通过强磁选抛尾富集弱磁选尾矿中的赤铁矿,第3步对强磁选精矿进行2段阶段细磨(一段磨至-0.038 mm占96.56%,二段磨至-0.019 mm占98.93%)、4段加磁种的选择性絮凝脱泥(以所得磁铁矿精矿为磁种,与强磁选精矿一起细磨),第4步对脱泥沉砂进行1粗1精4扫反浮选,最终获得了产率为32.33%、铁品位为63.55%、铁回收率为71.34%的综合铁精矿,从而为该矿石的合理开发利用提供了技术支撑。

Study on Magnetic Separation-Flocculation Desliming-Reverse Flotation of a Micro-fine Iron Ore

Iron minerals of an iron ore from Hunan are mainly magnetite and secondly hematite,and 12.12% of the iron exists in the form of silicate minerals.Among these,magnetite is middle or fine disseminated and hematite is disseminated in extremely microgranular.It is hard to achieve good separation index.According to the ore property,the process of stage grinding-low intensity magnetic separation(LIMS)-high intensity magnetic separation(HIMS)-selective flocculation desliming-reverse flotation was conducted.First,magnetite was concentrated through LIMS at coarse grinding fineness of 65.87% passing 0.075 mm.Second,hematite was enriched from tailings of LIMS by HIMS to discard gangue minerals.Third,two stage grinding (primary grinding at 0.038 mm accounted for 96.56%,second grinding at 98.93% passing 0.019 mm) and four stage selective flocculation desliming operation were adopted to deal with HIMS concentrate.Forth,reverse flotation of one roughing-one cleaning-four scavenging operation on underflow from desliming were made.Mixed iron concentrate with yield rate of 32.33%,iron grade of 63.55% and recovery of 71.34% was obtained,which provide technical basis for rational development and utilization of the ore.