中文摘要：

青海高原地区某金矿的原矿属于微细粒蚀变岩型金矿,浮选回收率低,调整浮选工艺参数后浮选效果也未得到明显提升。通过考察磨矿分级工艺并分析旋流器底流粒级筛析发现,旋流器的分级效率为43%-60%,且底流存在金的“反富集”现象,部分粒级金品位达到20×10^-6以上,这部分已单体解离的有用矿物循环累积于闭路作业中易产生过磨和矿泥二次包裹,从而限制了有用矿物的可浮性,使得回收率难以有效提升。通过在实验室模拟选厂工艺流程,在一段旋流器底流增加闪速浮选作业进行连续闭路试验,闪速浮选精矿产率达到4.07%,精矿品位达到38.31×10^-6。旋流器底流中已单体解离的有用矿物通过闪速浮选能达到“早收快收”的效果,减少了这些有用矿物过磨及矿泥二次包裹的几率。旋流器溢流再磨至选矿厂要求的浮选细度进行常规浮选闭路试验,综合回收率由常规浮选工艺下的80.90%提高至83.96%。

英文摘要：

The raw ore of a gold mine in plateau area of Qinghai Province belongs to fine grained altered rock type, the recovery rate of flotation is low.By adjusting the flotation process parameters,the fotation effect has not been significantly improved.Through investigation of grading classification process and analysis of hydrocyclone＇s underflow size sieve,it is found that the classification efficiency ofhydrocyclone is 43%- 60%, and the phenomenon of＂anti-enrichment＂ exist in the under flow,in which the gold content of some particles reached above 20×10^-6.Those useful minerals of monomeric dissociation were circulated in closed circuit process and easily causing overgrinding and slime encapsulation, which limited the flotability of useful minerals, so the recovery rate is difficult to effectively enhance.The simulation of manufacturing process was conducted in laboratory,by increasing flash flotation operation at the underflow ofa hydrocyclone,the yield of concentrate in flash flotation reached 4.07%, and the grade of gold in concentrate reached 38.31×10^-6.The useful mineral of monomeric dissociation in the underflow of a hydrocyclone has been collected by the flash flotation to achieve the effect of ＂early and quick collection＂ ,reducing the probability ofovergrinding and slime encapsulation of these useful minerals.The overflow continued to be ground to the required fineness to carry out closed-circuit test of routine flotation, and the comprehensive recovery of gold was increased from 80.90% under the conventional flotation process to 83.96%.