铜和锌离子对水热臭葱石沉砷过程的影响  

Effects of zinc and copper ions on ferric arsenate precipitation in hydrothermal scorodite

作　　者：张鹏 李存兄[1] 魏昶[1] 楚铭 张俊 邓志敢[1] 李旻廷[1] 李兴彬[1] ZHANG Peng;LI Cunxiong;WEI Chang;CHU Ming;ZHANG Jun;Deng Zhigan;LI Minting;LI Xingbin(School of Metallurgical and Energy Engineering,Kunming University of Science and Technology,Kunming 650093,China)

机构地区：[1]昆明理工大学冶金与能源工程学院

出　　处：《中南大学学报（自然科学版）》2019年第11期2645-2655,共11页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(51664038,51474117,51364022)~~

摘　　要：研究铜和锌离子质量浓度变化对Fe^2+氧化,Fe^3+与As^5+共沉淀形成臭葱石过程的作用机理以及对As和Fe沉淀率、沉砷渣化学组分和物相组成的影响规律。研究结果表明:由于Cu^2+/Cu^+离子对的催化作用,亚铁离子氧化速率加快,促进亚稳态碱式硫酸铁水热沉淀反应的发生,当初始Cu^2+质量浓度为20 g/L时,As和Fe沉淀率分别为96.9%和74.9%;沉砷渣中Cu主要以类质同象形式取代砷酸铁晶格中的铁形成砷酸铜类复杂化合物。Zn^2+质量浓度的增加促进了Fe^2+/SO4^2-离子对的氧化,使Fe^3+更易达到过饱和状态,导致亚稳态铁矾物相的生成,形成以臭葱石为主并伴有微量铁矾和碱式硫酸铁的聚合体。当初始Zn^2+质量浓度为20 g/L时,沉砷渣中As,Fe和S的质量分数分别为23.5%,28.5%和3.7%,其中Zn主要以聚合物的形式包覆在臭葱石表面。The effects of copper and zinc ions mass concentration on the mechanism of oxidation of Fe^2+,coprecipitation of Fe^3+and As^5+to form scorodite,the precipitation rate of As and Fe,and the chemical composition and phase composition of precipitate were studied.The results show that the catalytic action of Cu^2+/Cu+ion pair accelerates the oxidation rate of ferrous ions and promotes the hydrothermal precipitation reaction of metastable ferric subsulfate.When the initial mass concentration of Cu^2+is 20 g/L,the precipitation rates of As and Fe are 96.9%and 74.9%,respectively.Copper arsenate complex compounds are formed in the form of isomorphic substitution of copper in arsenic precipitate for iron in the lattice of ferric arsenate.The increase of Zn^2+mass concentration promotes the oxidation of Fe^2+/SO4^2-ion pairs,which makes Fe^3+easier to reach supersaturated state,and leads to the formation of metastable phase of jarosite.A polymer that mainly consists of scorodite is also formed,accompanied by trace jarosite and ferric subsulfate.When the initial mass concentration of Zn^2+is 20 g/L,the mass fractions of As,Fe and S in scorodite precipitate are 23.5%,28.5%and 3.7%,respectively.Among them,zinc is coated on the surface of scorodite mainly in the form of polymer.

关 键 词：水热法 臭葱石 铜 锌 碱式硫酸铁 草黄铁矾 

分 类 号：TF09[冶金工程—冶金物理化学]