云南某金矿的湿法预氧化工艺研究

Research on Wet Pre-oxidation Process for a Gold Mine in Yunnan

云南某金矿属于包裹金的难浸金矿,金精矿中的可见金绝大部分是包裹金,金精矿中的单体金不多,仅占可见金的4.17%,绝大部分以连生体存在,被脉石矿物包裹的可见金占可见金的87.5%,被黄铁矿包裹的可见金占可见金的8.33%。针对此特性,采用碱性常温常压强化预氧化工艺技术,充分利用机械活化和选择性氧化原理,利用超细磨塔式磨浸机的机械活化作用以及强化预氧化槽的强化搅拌作用,引发金精矿中的砷、硫矿物在高温高压下发生氧化反应,使砷、硫矿物中包裹金解离和暴露,金精矿由难浸转变成易浸,达到预氧化目的,然后进行氰化浸出回收金,金浸出率可提高到88.56%。

The flotation concentrate of a gold ore in Yunnan belongs to a refractory wrapped gold ore,in which most of the visible gold is the wrapped gold.The amount of the monomer gold is very little,only accounting for 4.17%,most of which exists in the form of intergrowth and among which the visible gold wrapped by gangue minerals and pyrite accounts for 87.5%and 8.33%respectively.Directed at this property,the technology of strengthening pre-oxidation under the condition of alkaline and normal temperature and pressure was adopted and making the mechanisms of mechanical activation and selective oxidation were applied.By making use of the mechanical activation of the ultrafine grinding tower mill and the agitation of the strengthening pre-oxidation tank,the oxidation reaction of the arsenic and sulfur in the gold concentrate was carried on under the normal temperature and pressure,which made the wrapped gold in the arsenic and sulfur was dissociated and exposed.The refractory gold concentrate could be leached easily,reaching the aim of pre-oxidation.Then the operation of cyanidation was carried on to recover gold.At last,the leaching rate of gold was improved from less 40%to 88.56%.