ABSTRACT

Vanadium-chromium reducing residue was not only a typical solid waste in the steel industry but also a valuable secondary source for recovery of vanadium and chromium. A highly efficient oxidative-alkaline-leaching technology with Na₂S₂O₈ was applied in this work. The effect of experimental factors including m(NaOH)/m(Residue), liquid-to-solid ratio, reaction temperature, m(Na₂S₂O₈)/m(Residue) and reaction time, on the leaching process were investigated. It was showed that 96.3% vanadium was leached out under selected conditions: m(NaOH)/m(Residue) = 0.30, liquid-to-solid ratio of 5 mL/g, reaction time of 60 min, m(Na₂S₂O₈)/m(Residue) = 0.50, reaction temperature of 90°C and stirring rate at 500 rpm, respectively. The leaching kinetics behaviour analysis demonstrated that the controlling step of the reaction was the diffusion of residue through the liquid film, and the Ea for vanadium leaching out was calculated to 15.57 kJ/mol. Response surface methodology was applied to analyze the interaction of the main conditions and the results showed that the influence of experimental factors on the leaching efficiency of vanadium followed the order: m(NaOH)/m(Residue) (B) > m(Na₂S₂O₈)/m(Residue) (C) > reaction temperature (E) > reaction time (D) > liquid-to-solid ratio (A).

摘要

钒铬还原渣不仅是钢铁工业中典型的固体废物，也是回收钒铬的宝贵二次资源。本工作采用了一种高效的Na ₂ S ₂ O ₈氧化碱浸技术。考察了m(NaOH)/m(Residue)、液固比、反应温度、m(Na ₂ S ₂ O ₈ )/m(Residue)和反应时间等实验因素对浸出过程的影响。 . 结果表明，在选定的条件下，96.3% 的钒被浸出：m(NaOH)/m(Residue) = 0.30，液固比为 5 mL/g，反应时间为 60 min，m(Na ₂ S ₂ ○₈ )/m(Residue) = 0.50，反应温度分别为 90°C 和搅拌速度为 500 rpm。浸出动力学行为分析表明，反应的控制步骤是残渣通过液膜的扩散，计算出钒浸出的Ea为15.57 kJ/mol。应用响应面法分析主要条件的交互作用，结果表明实验因素对钒浸出效率的影响顺序为：m(NaOH)/m(Residue) (B) > m(Na ₂ S ₂ O ₈ )/m(残渣) (C) > 反应温度 (E) > 反应时间 (D) > 液固比 (A)。