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.
作者
李宜昌
唐云
李国辉
李帅
代文治
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)
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)。
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
gold ore
oxidation pretreatment
non-cyanide leaching
quantum chemical calculation
iron nanoparticle
pyrite
ammonium persulfate
