A new mixed-valent iron arsenate black crystal  

一种新型混合价态铁的砷酸盐黑色晶体（英文）

作　　者：Jin-qin YANG Qing-zhu LI Li-yuan CHAI Qing-wei WANG Hui LIU Xiao-bo MIN Rui-yang XIAO 杨锦琴;李青竹;柴立元;王庆伟;刘恢;闵小波;肖睿洋(中南大学冶金与环境学院,长沙410083;中南大学国家重金属污染防治工程技术研究中心,长沙410083)

机构地区：[1]School of Metallurgy and Environment, Central South University, Changsha 410083, China [2]National Engineering Research Centre for Control and Treatment of Heavy Metal Pollution, Central South University, Changsha 410083, China

出　　处：《Transactions of Nonferrous Metals Society of China》2018年第5期1036-1044,共9页中国有色金属学报（英文版）

基　　金：Project(51634010)supported by the Key Project of National Natural Science Foundation of China;Project(51304251)supported by the National Natural Science Foundation of China;Project(201509050)supported by Special Program on Environmental Protection for Public Welfare of China

摘　　要：Scorodite（FeAsO4·2H2O）is the most popular phase for arsenic（As）immobilization while the reductive dissolution of Fe（Ⅲ）to Fe（Ⅱ）will promote As release.In the present study,an equilibrium between Fe（Ⅲ）and Fe（Ⅱ）was achieved in scorodite preparation system by introducing certain alcohol（methanol,ethanol,isopropanol or tert-butanol）,and thus a new mixed-valent iron arsenate black crystal formulated as Fe（Ⅱ）（5.2）Fe（Ⅲ）（8.8）（HAsO4）4（AsO4）8·H2O was prepared.In comparison with scorodite,the black crystal has higher As content（36.4%,mass fraction）and lower crystal water content（0.73%,mass fraction）.Additionally,the leaching concentration of As can be lower than the threshold value（5 mg/L）regulated by identification standards for hazardous wastes of China（GB 5080.3-2007）.Therefore,this new mixed-valent iron arsenate crystal could be classified as a non-hazardous and promising As-bearing phase in environmental applications.臭葱石(FeAsO_4·2H_2O)是应用最广泛的固砷相,但Fe(Ⅲ)还原溶解为Fe(Ⅱ)会促进砷的释放。本研究向臭葱石的制备体系中引入某种醇(甲醇、乙醇、异丙醇或叔丁醇)使Fe(Ⅲ)和Fe(Ⅱ)达到平衡并制备出一种新型混合价态铁的砷酸盐黑色晶体,其分子式为Fe(Ⅱ)_(5.2)Fe(Ⅲ)_(8.8)(AsO_4H)_4(AsO_4)_8·H_2O。与臭葱石相比,该黑色晶体具有较高的砷含量(36.4%,质量分数)和较低的结晶水含量(0.73%,质量分数)。另外,砷的浸出浓度可以低于中国危险废物鉴别标准规定的阈值(5mg/L)。因此,这种新型混合价态铁的砷酸盐晶体可以被归为一种在环境应用上极具前景的非毒性含砷相。

关 键 词：ARSENIC IRON CRYSTAL arsenic immobilization hazardous wastes 

分 类 号：X705[环境科学与工程—环境工程]