Preparation of Cr_2O_3 precursors by hydrothermal reduction in the abundant Na_2CO_3 and Na_2CrO_4 solution

作     者：Guang-ye Wei Jing-kui Qu Yu-dong Zheng Tao Qi Qiang Guo 

作者机构：School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology Beijing 100190 China Key Laboratory of Green Process and Engineering Institute of Process Engineering Chinese Academy of Sciences Beijing 100190 China 

出 版 物：《International Journal of Minerals,Metallurgy and Materials》 (矿物冶金与材料学报（英文版）)

年 卷 期：2012年第19卷第11期

页      面：978-985页

核心收录：

学科分类：080603[工学-有色金属冶金] 0819[工学-矿业工程] 0806[工学-冶金工程] 08[工学] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 

基　　金：the National Science Foundation for Distinguished Young Scholars of China(No.51125018) the National Key Technologies R&D Program(No.2011BAC06B07) the National High-Tech R&D Program of China(No.2011AA060704) Henan Yongtong Nickel Industry Co.,Ltd 

主　　题：chromium oxide hydrothermal reduction sodium carbonate methanal laterite ores 

摘      要：Precursors of chromium oxide （p-Cr203） were prepared by reducing hexavalent chromium in the presence of sodium carbonate solution under hydrothermal conditions. Methanal was used as the reductant, and carbon dioxide was the acidulating agent. The influences of reaction temperature, initial pressure of carbon dioxide, isothermal time and methanal coefficient on Cr（VI） reduction were investigated. Ex- perimental results showed that Cr（VI） was reduced to Cr（III） with a yield of 99%. Chemical titration, thermogravimetry （TG）, X-ray diffrac- tion （XRD） analysis, and scanning electron microscopy （SEM） were used to characterize the p-Cr203 and Cr203. The series of p-Cr203 were found to be multiphase even if they presented different colors, from gray green to lavender. After these p-Cr203 samples were calcined, the product of rhombohedral Cr203 with a purity of 99.5wt% was obtained.