Thermodynamic analysis for separation of vanadium and chromium in V(Ⅳ)-Cr(Ⅲ)-H_2O system  

V(Ⅳ)-Cr(Ⅲ)-H_2O体系钒铬分离的热力学分析（英文）

作　　者：Bian-fang CHEN Sheng HUANG Biao LIU Qi GE Shu-shan XIE Ming-yu WANG Xue-wen WANG 陈边防;黄胜;刘彪;葛奇;谢舒珊;王明玉;王学文(中南大学冶金与环境学院,长沙410083)

机构地区：[1]School of Metallurgy and Environment,Central South University,Changsha 410083,China

出　　处：《Transactions of Nonferrous Metals Society of China》2018年第3期567-573,共7页中国有色金属学报（英文版）

基　　金：Project(51104186)supported by the National Natural Science Foundation of China;Project(2016JJ2142)supported by the Natural Science Foundation of Hunan Province,China;Project supported by the Open-End Fund for the Valuable and Precision Instruments of Central South University,China

摘　　要：To recycle vanadium and chromium from the V?Cr-bearing reducing slag,the thermodynamics of separating V(IV)and Cr(III)at 298 K was summarized in the form of potential-pH diagram and activity-pH diagram.The potential-pH diagrams of V-Mn-H2O and Cr-Mn-H2O systems show that the electrode potential of MnO2/Mn2+is higher than that of VO2+/VO2+but lower than that of Cr2O7 2-/Cr3+,which proves that it is feasible to selectively oxidize low valent vanadium using MnO2.The activity-pH diagrams of V(V)-H2O and Cr(III)-H2O systems show that the precipitation pH of V(V)is far lower than that of Cr(III),and therefore V(V)and Cr(III)can be separated through precipitation method.Based on the thermodynamic analysis,the flowsheet of recovery of vanadium and chromium from the V-Cr-bearing reducing slag is designed.为了从钒铬还原渣中回收钒和铬,以电位-pH和活度-pH的形式总结298 K时V(Ⅳ)和Cr(Ⅲ)分离的热力学。V-Mn-H_2O体系和Cr-Mn-H_2O体系的电位-pH图表明,MnO_2/Mn^(2+)的电极电位高于VO_2^+/VO^(2+)的电极电位,但是低于Cr_2O_7^(2-)/Cr^(3+)的电极电位,这表明采用MnO_2来选择性氧化低价钒是可行的。V(Ⅴ)-H_2O体系和Cr(Ⅲ)-H_2O体系的活度-pH图表明,V(Ⅴ)开始沉淀时的pH远低于Cr(Ⅲ)开始沉淀时的pH,因此可以采用沉淀析出法分离V(Ⅴ)和Cr(Ⅲ)。通过热力学分析,设计了钒铬还原渣中分离回收钒和铬的技术路线。

关 键 词：V-Cr-H2O system VANADIUM CHROMIUM selective oxidation selective precipitation 

分 类 号：TF791[冶金工程—钢铁冶金] TF841.3