马达加斯加某三水铝土矿磨矿浮选脱硅工艺试验研究

Study on Grinding and Desilication Flotation Process of a Gibbsite Bauxite Ore in Madagascar

铝土矿试验矿样来自马达加斯加Sofia地区,Al_(2)O_(3)含量为32.06%,SiO_(2)含量为34.06%。矿石中含铝矿物主要为三水铝石;含硅矿物主要为石英,其次为高岭石。三水铝石以微晶聚合体形式存在,微细粒的其他矿物以包体形式嵌布在其中,矿样粒级越细聚合体中杂质矿物含量越高。矿样中-0.028mm粒级产率约占30%,高杂质含量的三水铝石聚合体占比超过95%,反浮选或正浮选几乎没有脱硅效果。石英的嵌布粒度集中于0.1~0.8mm,原矿矿样常规破碎磨矿产品中SiO_(2)在0.074mm以上粗粒级富集,富含石英矿物的矿粒过粗,采用反浮选无法脱除。研究提出了便于工业化实施的脱泥、分级、分别磨矿合并反浮选工艺流程,未破碎原矿矿样用2mm的筛子筛分,+2mm粒级矿样单独破碎磨矿,-2mm粒级矿样脱泥、沉砂单独磨矿,两种磨矿产品合并进入反浮选脱硅,获得铝硅比大于10、Al2O_(3)回收率大于40%的精矿。

The test bauxite sample was from Sofia area of Madagascar,with a Al_(2)O_(3) content of 32.06%and a SiO_(2) content of 34.06%.The aluminum bearing minerals in the ore are mainly gibbsite,and the silica bearing minerals are mainly quartz,followed by kaolinite.Gibbsite exists in the form of microcrystalline aggregates,and other fine grained minerals are embedded in it in the form of xenolith.The finer the particle size of the raw ore sample,the higher the content of impurity minerals in the aggregates.-0.028 mm particle size fraction of raw ore with a yield of about 30%,in which the gibbsite aggregates with lots of impurity mineral accounts for more than 95%,having little desilication effect in reverse flotation or positive flotation.The embedded granularity of quartz is concentrated in the size range O.1~0.8 mm.SiO,in the conventional crushing and grinding products of raw ore is enriched in the coarse particle size of above O.074 mm,The ore particles which mainly contain quartz minerals are too coarse and cannot be removed by reverse flotation.A grinding and flotation process easy to industrialization has been put forward.The uncrushed raw ore is screened for 2 mm,the+2 mm particle size ore sample is crushed and ground separately,and the 2 mm particle size is deslimed and ground separately.The two grinding products are combined and fed into reverse flotation desilication,and a concentrate with A/S above 10 and Al,Os recovery greater than 40%can be obtained.