φ-pH diagrams and kinetics of V_(2)O_(3) prepared by solution-phase hydrogen reduction  

液相氢还原制备V2O3的φ-pH图和动力学研究

作　　者：Yi-bo HU Yi-min ZHANG Nan-nan XUE Peng-cheng HU Liu-hong ZHANG 胡艺博;张一敏;薛楠楠;胡鹏程;张刘洪(武汉科技大学资源与环境工程学院,武汉430081;武汉科技大学国家环境保护矿冶资源利用与污染控制重点实验室,武汉430081;钒资源高效利用湖北省协同创新中心,武汉430081;武汉科技大学湖北省页岩钒资源高效清洁利用工程技术研究中心,武汉430081)

机构地区：[1]College of Resources and Environmental Engineering,Wuhan University of Science and Technology,Wuhan 430081,China [2]State Environmental Protection Key Laboratory of Mineral Metallurgical Resources Utilization and Pollution Control,Wuhan University of Science and Technology,Wuhan 430081,China [3]Hubei Collaborative Innovation Center for High Efficient Utilization of Vanadium Resources,Wuhan 430081,China [4]Hubei Provincial Engineering Technology Research Center of High Efficient Cleaning Utilization for Shale Vanadium Resource,Wuhan University of Science and Technology,Wuhan 430081,China

出　　处：《Transactions of Nonferrous Metals Society of China》2022年第4期1290-1300,共11页中国有色金属学报（英文版）

基　　金：financially supported by the National Key R&D Program of China(No.2020YFC1909700);Outstanding Young and Middle-aged Science and Technology Innovation Team Project of Hubei Province,China(No.T201802);the National Natural Science Foundation of China(No.52004187)。

摘　　要：Solution-phase hydrogen reduction(Sp HR)was introduced into V_(2)O_(3)preparation to overcome disadvantages of traditional reduction roasting,which include a long process,high energy consumption,and generation of pollution.The research mainly focuses onφ-pH diagrams and kinetics of SpHR.Thermodynamic analysis ofφ-pH diagrams for the V-H_(2)O system demonstrates that V_(2)O_(3)preparation via Sp HR requires a high temperature,a high vanadium concentration,and sufficient hydrogen in acidic solution.Kinetic analyses show that the activation energy of V_(2)O_(3)preparation via SpHR is 38.0679 k J/mol,indicating that the reduction is controlled by a combination of interfacial chemical reaction and internal diffusion.Effects of H;partial pressure(slope K=0.05246)on the reaction rate is not as significant as the vanadium concentration(K=1.58872).V_(2)O_(3)crystals with a purity of 99.59%and a vanadium precipitation rate of 99.83%were obtained under the following conditions:pH=5-6,c(V_(2)O_(3))=0.5 mol/L,p(H;)=4 MPa,m(PdCl;)=10 mg,T=250℃,and t=2.5 h.为了克服V_(2)O_(3)传统还原焙烧工艺具有的流程长、能耗高、污染大的缺点,采用液相氢还原(Sp HR)方法制备V_(2)O_(3),并对V-H_(2)O体系的φ-pH图和沉钒动力学进行分析。V-H_(2)O系φ-pH图的热力学分析表明:在酸性溶液中,通过液相氢还原制备V_(2)O_(3)需要较高的温度和钒浓度,以及充足的氢气。动力学研究表明:SpHR法制备V_(2)O_(3)的活化能为38.0679 k J/mol,表明该过程受界面化学反应和内扩散的混合步骤控制;氢分压(斜率k=0.05246)对反应速率的影响不如钒浓度(K=1.58872)显著。在pH=5~6、c(V_(2)O_(3))=0.5 mol/L、p(H;)=4 MPa、m(PdCl;)=10 mg、T=250℃及t=2.5 h的条件下,获得纯度为99.59%和沉钒率为99.83%的V_(2)O_(3)晶体。

关 键 词：V2O3 solution-phase hydrogen reduction φ-pH diagram KINETICS 

分 类 号：TQ135.11[化学工程—无机化工]