Key Laboratory of Colloid and Interface Science of Education Ministry, Shandong University, Jinan 250100, China; College of Petrochemical Technology, Lanzhou University of Technology, Lanzhou 730050, China.
Key Laboratory of Colloid and Interface Science of Education Ministry, Shandong University, Jinan 250100, China.
Waste Manag. 2024 Oct 1;187:198-206. doi: 10.1016/j.wasman.2024.07.022. Epub 2024 Jul 24.
This article employs six organic acids to selectively dissolve Mo, Ni and V from spent catalysts, and the most effective acid is identified. Then, the effects of key leaching parameters, including acid concentration, temperature, and S/L ratio, on metal leaching are systematically explored to determine the leaching mechanism. The results demonstrate that the leaching ability of organic acids followed the order: oxalic acid > citric acid > tartaric acid > malonic acid > acetic acid > formic acid. The leaching process of metals was jointly influenced by acidolysis and complexolysis. Among them, more than 93.07 % of Mo, 86.64 % of V, and 74.21 % of Ni were selectively leached with oxalic acid at the optimum condition: S/l: 1/20, oxalic acid: 1.0 mol/L, temp: 60 °C. From the correlation coefficients, the resulting activation energies, and n values, it was demonstrated that Mo and V followed the Avrami dissolution reaction model, V leaching was controlled by the diffusion mode, and Mo leaching was controlled by a mixed mode of chemical reaction and diffusion. The dissolution behavior of both metals consistently adhered to the linear trend of the Avrami kinetic model under varying S/L ratios and oxalic acid concentrations.
本文采用 6 种有机酸选择性溶解废催化剂中的 Mo、Ni 和 V，确定了最有效的酸。然后，系统研究了关键浸出参数，包括酸浓度、温度和固液比（S/L）对金属浸出的影响，以确定浸出机理。结果表明，有机酸的浸出能力顺序为：草酸＞柠檬酸＞酒石酸＞丙二酸＞乙酸＞甲酸。金属的浸出过程受酸解和络合的共同影响。其中，在最佳条件下（S/L：1/20、草酸：1.0 mol/L、温度：60°C），用草酸可选择性浸出 93.07%以上的 Mo、86.64%的 V 和 74.21%的 Ni。从相关系数、得出的活化能和 n 值可以看出，Mo 和 V 遵循 Avrami 溶解反应模型，V 的浸出受扩散模式控制，Mo 的浸出受化学反应和扩散混合模式控制。在不同的 S/L 比和草酸浓度下，两种金属的溶解行为都一致地遵循 Avrami 动力学模型的线性趋势。
