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.
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.
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