某金矿磨矿分级回路中重选流程结构研究与实践

Study and Practice of Gravity Separation Process Structure in Grinding-Classification Circuit of a Gold Mine

塔吉克斯坦某金矿的矿石类型为低硫含砷石英长石型金矿石,属于少金属硫化物-金-石英矿石,金矿物嵌布粒度粗细不均,且以微细粒嵌布为主,主要集中于5~20μm。根据确定的磨矿细度,设计了两段闭路磨矿流程,并在磨矿分级回路中配置了重选流程。对该矿磨矿分级回路中的重选流程结构进行了研究,确定了适合该矿的最佳结构形式,取得了良好的分选指标。在磨矿细度为-0.074mm占90%~95%的条件下,原矿中金品位为1.85g/t时,将重选流程放在二段球磨排矿回路,可获得金品位1 769.71g/t,金回收率为18.24%的尼尔森精矿。尼尔森精矿经摇床重选后,可获得金品位127 284.55g/t,金回收率为10.47%的摇床精矿。对一段旋流器溢流和二段旋流器溢流产品进行粒度筛析发现,重选流程主要回收矿石的中、细粒级金矿物,这与金矿物在矿石中的嵌布粒度一致。

The ore type of a gold mine in Tajikistan is low sulfur arsenic bearing quartz feldspar type gold ore,which belongs to low metal sulfide-gold-quartz ore.The disseminated grain size of the gold ore is uneven,and it is mainly micro-fine disseminated,mainly concentrated in 5~20μm.According to the determined grinding fineness,a two-stage closed-circuit grinding process is designed,and a gravity separation process is configured in the grinding and classification circuit.The gravity separation process structure in the grinding and classification circuit of the mine was studied,and the optimal structure form suitable for the mine was determined,and good separation indexes was obtained.When the grinding fineness of-0.074 mm is accounting for 90%-95%,and the gold grade of ROM is 1.85 g/t,the Knelson concentrate with gold grade of 1769.71 g/t and gold recovery of 18.24%can be obtained by placing the gravity separation process in the secondary ball mill discharge circuit.After shaking table gravity separation of Knelson concentrate,the shaking table concentrate with gold grade of 127284.55 g/t and gold recovery of 10.47%can be obtained.According to the analysis of the particle size of overflow products from the first stage cyclone and the second stage cyclone.It is found that the gravity separation process mainly recovers medium and fine-grained gold minerals,which is consistent with the disseminated particle size of gold minerals in the ore.