纳米铁粉—过硫酸铵氧化预处理对某微细浸染型金矿非氰浸出的影响及量子化学计算  

Effect of Nano Iron Powder-ammonium Persulfate Oxidation Pretreatment on Non-Cyanide Leaching of a Fine Disseminated Gold Ore and Quantum Chemical Calculation

作　　者：李宜昌 唐云[1,2] 李国辉 李帅 代文治[1,2] LI Yichang;TANG Yun;LI Guohui;LI Shuai;DAI Wenzhi(Mining College,Guizhou University,Guiyang 550025,China;Guizhou Key Laboratory for Com-prehensive Utilization of Nonmetal Mineral Resources,Guiyang 550025,China)

机构地区：[1]贵州大学矿业学院,贵州贵阳550025 [2]贵州省非金属矿产资源综合利用重点实验室,贵州贵阳550025

出　　处：《矿产保护与利用》2023年第1期50-56,共7页Conservation and Utilization of Mineral Resources

基　　金：国家自然科学基金项目(51864010);贵州省省级科技计划项目(黔科合基础[2017]1404,黔科合平台人才[2018]5781)。

摘　　要：以微细浸染型原生金矿石为研究对象,采用纳米铁粉(nZVI)-/过硫酸铵(APS)体系氧化预处理载金黄铁矿后加入非氰浸金剂,并运用量子化学计算nZVI-APS体系产生的中间体SO_(4)^(-)·强化氧化黄铁矿的反应路径。试验结果表明:在APS用量4 kg/t、nZVI用量4 kg/t、预处理时间4 h、NaOH用量10 kg/t、浸金剂金蝉用量10 kg/t和浸出时间2 h条件下,获得金的浸出率为87.93%。量子化学计算结果表明:在nZVI-APS体系中,黄铁矿的氧化预处理反应路径为第一过渡态(TS1)→中间体(IC)→第二过渡态(TS2),其中TS1是该体系产生SO_(4)^(-)·的速控步;Fe^(2+)与APS中的S原子、O原子和O桥键均产生吸附,而O桥键上的吸附成键最为稳定;SO_(4)^(-)·均能氧化黄铁矿中的Fe和S,其中Fe是主要的反应活性点。A micro-disseminated primary gold ore was taken as the research object and the gold-bearing pyrite was pretreated with the nano iron powder(nZVI)-ammonium persulfate(APS)system before treated with a non-cyanide leaching agent.The reaction path of oxidized pyrite enhanced by the intermediate SO_(4)^(-)∙produced by nZVI-APS system,was calculated by quantum chemical calculation.The results showed that the leaching rate of gold reached 87.93%under the conditions of APS dosage of 4 kg/t,nZVI dosage of 4 kg/t,pretreatment time of 4 h,NaOH dosage of 10 kg/t,leaching agent of gold cicada dosage of 10 kg/t,and leaching time of 2 h.Notably,quantum chemical calculations revealed that the reaction path of oxidation pretreatment of pyrite in the nZVI-APS system was the first transition state(TS1)→intermediate(IC)→second transition state(TS2),where TS1 was the rate-controlling step for the production of SO_(4)^(-)∙in the system.Specifically,Fe^(2+)adsorbed with the S atom,O atom,and O bridge bond in APS,with the adsorption bond on the O bridge bond exhibiting the most stability.Additionally,the SO_(4)^(-)∙could oxidize Fe and S in pyrite,with Fe serving as the main active site.

关 键 词：金矿 氧化预处理 非氰浸出 量子化学计算 纳米铁粉 黄铁矿 过硫酸铵 

分 类 号：TD953.1[矿业工程—选矿] TD925.6[冶金工程—有色金属冶金] TF803.2