某含砷难浸金精矿常温常压强化碱浸预处理试验研究

A Study on intensified alkaline leaching pretreatment method to Yangshu refractory gold ore at normal temperature and pressure

采用物理与化学综合分离方法 ,利用边磨边浸工艺及其主体设备———塔式磨浸机 ,对含砷难浸金精矿进行超细磨 ,然后在常温常压下 ,利用强化预处理搅拌槽进行强化碱浸预处理 ,从而脱砷脱硫或使金与硫化物充分解离 ,再进行氰化 ,可达到高效提金的目的。这一新工艺用于预处理产于杨树地区的含砷难浸金精矿 ,在 97.38%- 35 .5 6 μm的磨矿细度、矿浆浓度4 0 %和环境温度 13～ 15℃条件下 ,强化碱浸 12h后 ,砷转化率 92 .1%,S氧化率 70 .2 %,金的氰化浸出率从预处理前的 17.5 %提高到 98.0 %,金的炭吸附率 99.3%,锌粉置换率 99.5 %,排放尾液含砷 0 .4 3mg/L。如按 30t/d规模核算 ,预处理成本为 310元 ,预处理设备投资为 180万元。该结果表明 ,这一新工艺可以高效地回收难浸金精矿中的金 ,且工艺简单 ,流程短 ,投资小 。

This new pretreatment method is a synthetic physical and chemiscal method .In a tower type grinding and leaching mill,the Yangshu arsenic-containing refractory gold concentrate is ground to 97.38%～33.56μm, then be intensified leaching to 12h by 144kg/t NaOH in a forced agitator tank with the pulp conc. of 40% wt at temperature of 13～15℃ and normal pressure (1atm).The arsenic particles and sulphide particles are selectively oxidation at the oxidation rate of As of 92.1% and 70.2% of S.Then the gold bound by them is exposed and then can be highly recovered by cyanide leaching. The result shows that the gold leaching rate by cyanide is enhanced from 17.5% to 98% after pretreatment.The cost of pretreatment is 310yuan/t .The investment of pretreatment machine of 30t/d is 1.8 million yuans.Now a pretreatment plant of refractory gold concentrate of 10t/d has been erected with success in China. Other two plants of 10t/d and 30t/d are being built. For some refractory gold ore,this new process is an effective pretreatment method with low investment,low cost,simple control,short flowsheet and safety to environment.