铜和锌离子对水热臭葱石沉砷过程的影响

来源期刊:中南大学学报(自然科学版)2019年第11期

论文作者:李存兄 张鹏 魏昶 楚铭 张俊 邓志敢 李旻廷 李兴彬

文章页码:2645 - 2656

关键词:水热法;臭葱石;铜;锌;碱式硫酸铁;草黄铁矾

Key words:hydrothermal; scorodite; copper; zinc; ferric subsulfate; hydronium jarosite

摘    要:研究铜和锌离子质量浓度变化对Fe2+氧化,Fe3+与As5+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Cu2+/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Cu2+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。Zn2+质量浓度的增加促进了Fe2+/SO 离子对的氧化,使Fe3+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Zn2+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。

Abstract: The effects of copper and zinc ions mass concentration on the mechanism of oxidation of Fe2+, co-precipitation of Fe3+ and As5+ 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 Cu2+/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 Cu2+ 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 Zn2+ mass concentration promotes the oxidation of Fe2+/SO ion pairs, which makes Fe3+ 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 Zn2+ 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.

有色金属在线官网  |   会议  |   在线投稿  |   购买纸书  |   科技图书馆

中南大学出版社 技术支持 版权声明   电话:0731-88830515 88830516   传真:0731-88710482   Email:administrator@cnnmol.com

互联网出版许可证:(署)网出证(京)字第342号   京ICP备17050991号-6      京公网安备11010802042557号