College of Chemistry and Chemical Engineering, Yangtze Normal University, Chongqing, 400044, China.
College of Chemistry and Chemical Engineering, Chongqing University, Chongqing, 400044, China.
Sci Rep. 2018 Jan 11;8(1):426. doi: 10.1038/s41598-017-18918-2.
Hydrogen peroxide as an oxidant was applied in leaching of vanadium and chromium in concentrated NaOH solution. Under the optimal reaction conditions (the liquid to solid ratio of 4.0 ml/g, residue particle size of <200 mesh, the mass ratio of NaOH-to-residue of 1.0 g/g, the volume ratio of HO-to-residue of 1.2 ml/g, reaction temperature of 90 °C and reaction time of 120 min), the leaching efficiency of vanadium and chromium could reach up to 98.60% and 86.49%, respectively. Compared with the current liquid-phase oxidation technologies, the reaction temperature was 90-310 °C lower, and the NaOH concentration of the reaction medium is lower by more than 50 wt% (the mass ratio of NaOH-to-residue of 1.0 g/g equals to concentration of 20 wt%). The kinetics study revealed that leaching process of chromium and vanadium were interpreted with shrinking core model under chemical reaction control. The apparent activation energy of chromium and vanadium dissolution was 22.19 kJ/mol and 6.95 kJ/mol, respectively.
过氧化氢作为氧化剂用于在浓氢氧化钠溶液中浸出钒和铬。在最佳反应条件下（液固比为 4.0 ml/g，残渣粒径<200 目，氢氧化钠与残渣的质量比为 1.0 g/g，HO 与残渣的体积比为 1.2 ml/g，反应温度为 90°C，反应时间为 120 min），钒和铬的浸出效率分别达到 98.60%和 86.49%。与当前的液相氧化技术相比，反应温度低 90-310°C，反应介质中的氢氧化钠浓度低 50%以上（氢氧化钠与残渣的质量比为 1.0 g/g 相当于 20%wt）。动力学研究表明，在化学反应控制下，铬和钒的浸出过程可用收缩核模型来解释。铬和钒溶解的表观活化能分别为 22.19 kJ/mol 和 6.95 kJ/mol。
