某铅锌矿中矿银赋存状态及回收试验研究

Experimental Study on Occurrence and Recovery of Silver in a Lead-Zinc Mine

针对内蒙古某大型铅锌矿现场生产铅精矿中伴生银回收率低的现状,采用全流程查定方式分析全流程银元素的走向,并以现场产出的铅中矿1为研究对象,重点分析其化学组成、银矿物种类及分布率、银嵌布特征等影响铅精矿中银回收率的关键因素。结果表明,铅中矿1中的银主要以银黝铜矿、辉银矿形式被黄铁矿包裹或以裂隙银的形态充填于黄铁矿-方铅矿连生体之间,且银矿物嵌布粒径微细,铅中矿1中的银矿物解离度较低,致使现有的高碱工艺无法回收该部分的银矿物。据此推荐采用铅中矿1分级再磨与低碱条件下抑制黄铁矿相结合的优化工艺方案,实现铅精矿中银回收率的进一步提升。

In view of the low recovery of associated silver in lead concentrate from a large-scale lead-zinc mine in Inner Mongolia,the trend of silver element in the whole process was analyzed by using the whole process assessment method.Taking the lead middling 1 produced in the field as the research object,the key factors affecting the recovery rate of silver in lead concentrate,such as its chemical composition,silver mineral types and distribution rate,and silver dissemination characteristics were analyzed.The results showed that silver in lead middling 1 was mainly wrapped by pyrite in the form of freibergite and argentite or filled in the intergrowth of pyrite and galena in the form of fissure silver,and the disseminated particle size of silver minerals was very fine,and the liberation degree of silver minerals in lead middling 1 was low,so that the existing high-alkali process can not recover the silver minerals in this part.Therefore,it was recommended to adopt the optimized process scheme of the combination of the first classification regrinding of lead middlings and the suppression of pyrite under the condition of low alkali,so as to further improve the recovery of silver in lead concentrate.