提高某微细粒铅锌矿选锌指标的试验研究

某铅锌矿含铅7.31%、含锌13.70%，含硫量高且含炭质，锌矿物主要以闪锌矿形式存在。闪锌矿与方铅矿、黄铁矿嵌布关系密切，嵌布粒度分布不均匀且整体偏细，为锌选别带来一定的困难。为改善锌精矿的粒度分布、优化锌选别指标，采用“快速分支浮选—中矿再磨精选”流程处理锌浮选给矿，开展了浮选时间、药剂制度和中矿再磨细度等条件试验。结果表明，新工艺流程处理后，最终可获得锌品位为53.88%、锌回收率为91.57%的综合锌精矿，较原工艺流程，锌精矿品位和回收率分别提升了1.56和1.13个百分点；锌精矿粒度分布明显改善，+38 μm含量由5.93%提高到22.50%，-7 μm含量由47.54%降低到29.41%。新工艺解决了原工艺流程锌再磨选择性不高、部分闪锌矿过磨、部分闪锌矿连生体无法充分解离的问题，也显著降低了再磨负荷。

Experimental Study on Optimizing Zinc Flotation Indexes of a Fine-grained Lead-Zinc Ore

The lead grade and zinc grade of a lead-zinc ore is 7.31% and 13.70%， respectively， with high sulfur contents and carbonaceous. The zinc minerals mainly exist in the form of sphalerite. The distribution particle of sphalerite is uneven and fine， which embedded with galena and pyrite closely， causing the difficulties in zinc separation. In order to improve the particle size distribution of zinc concentrate and optimize the zinc separation indexes， the process of "rapid branching floatation and middling regrinding cleaning" was adopted to treat the zinc flotation feeding. The condition test involving flotation time， reagent system and middling regrinding fineness were conducted. The results showed that the comprehensive zinc concentrate with zinc grade of 53.88% and zinc recovery of 91.57% could be obtained after the new process， which is 1.56 and 1.13 percentage points higher than the original process， respectively. Also， the particle size distribution of zinc concentrate was significantly improved. The contents above 38 μm increased from 5.93% to 22.50%， and the contents below 7 μm decreased from 47.54% to 29.41%. The new process solves the problems of low selectivity of zinc regrinding， overgrinding of some sphalerite and insufficient dissociation of some sphalerite intergrowth in the original process， and reduced the regrinding loading.