氯化浸取钢渣中钒的动力学研究

Dynamics Study on Vanadium Extraction Technology from Chloride Leaching Steel Slag

摘要:

为了提高湿法浸出低钒钢渣中钒的浸出率，并为湿法浸出低钒钢渣中钒提供理论依据，从动力学角度分析整个浸出过程，并考察温度、液/固比、浸出时间和搅拌速度对浸出过程的影响。结果表明，在90 ℃，液/固比为10:1以及4.0 mol/L盐酸，过氧化氢8.0 mL，浸取90 min条件下，低钒钢渣中钒的浸出率可达到98.8%。通过正交实验和动力学推导，得到描述浸出过程的经验方程。低钒钢渣湿法浸出钒的动力学模型为未反应收缩核模型，浸出过程的表观活化能为7.21 kJ/mol。该模型表明浸出过程中的控制步骤取决于边界层的扩散速度。提高温度、液/固比和浸出时间，均可增加钒的浸出速度，提高钒的浸出率。

Abstract:

Aiming to improve vanadium leaching rate and provide theoretical basis for vanadium leaching from low-vanadium steel slag through wet leaching, the whole leaching process was studied in dynamics and effects of temperature, liquid-solid ratio, leaching time and stirring velocity were observed. Results show that vanadium leaching rate from low-vanadium steel slag could reach to 98.8% at 90 °C when leaching in the solution with liquid-solid ratio of 10:1 and containing 4.0 mol/L hydrochloric acid and 8.0 mL hydrogen peroxide for 90 min. An empirical equation describing the leaching process was obtained from orthogonal experiment and dynamics derivation. The dynamical model of wet leaching vanadium from low-vanadium steel slag is the unreacted shrinking core model while the apparent activation energy of the leaching process is 7.21 kJ/mol. The model shows that control steps of the leaching process depend on the diffusion speed of the boundary layers. Vanadium leaching velocity could be sped up and the yield could be improved by enhancing temperature, liquid-solid ratio and leaching time.