硫化铟氧化酸浸与常规酸浸的动力学比较

为了提高硫化铟的浸出率,从研究硫化铟常规酸浸、高锰酸钾或双氧水氧化酸浸的晶粒参数、表观活化能、反应级数的变化规律入手,对不同状态下硫化铟的浸出动力学进行了研究。结果表明:①硫化铟浸出反应的表观活化能、反应级数、晶粒参数,在常规酸浸状态下分别为35.6 kJ/mol、0.770、0.576,高锰酸钾氧化酸浸状态下分别为13.9 kJ/mol、0.390、0.366,双氧水氧化酸浸状态下分别为17.5 kJ/mol、0.220、0.466。②硫化铟常规酸浸的铟浸出率对浸出温度、硫酸初始浓度的变化比较敏感;而硫化铟氧化酸浸的表观活化能和反应级数均大幅度下降,化学活性显著增强,反应速率明显加快,浸出温度和硫酸初始浓度对铟浸出影响的敏感度下降。③硫化铟的常规酸浸及氧化酸浸动力学模型符合n1的Avrami方程,常规酸浸受化学反应与扩散混合控制,而氧化酸浸则受扩散控制,因此,强化搅拌扩散有利于提高铟浸出率。

Kinetics Comparison of Oxidizing Acid Leaching and Conventional Acid Leaching of Indium Sulfide

Kinetics of indium sulfide leaching under different conditions was investigated，in order to improve the leaching rate of indium sulfide fundamentally，by starting with the change law of grain parameter，apparent activation energy and reaction order of conventional acid leaching，potassium permanganate & hydrogen peroxide oxidizing acid leaching of indium sulfide.The results showed that:①The apparent activation energy，reaction order and crystalline parameter of the leaching reaction of indium sulfide were 35.6 kJ/mol，0.770，0.576 respectively under conventional acid leaching conditions，13.9 kJ/mol，0.390，0.366 under potassium permanganate oxidizing acid leaching and 17.5 kJ/mol，0.220，0.466 under hydrogen peroxide oxidizing acid leaching;②Indium leaching rate in conventional acid leaching was more sensitive to changes of leaching temperature and initial concentration of sulfuric acid，while for oxidizing acid leaching，the apparent activation energy and reaction order were significantly reduced，chemical activity significantly enhanced and the reaction rate was accelerated，the sensitivity of temperature and initial concentration of sulfuric acid on the influence of indium leaching was reduced;③The kinetics model of indium sulfide of conventional leaching and oxidation leaching fit Avrami equation well at n＜1.Conventional leaching was controlled by both diffusion and reaction of chemistry，and the oxidation leaching process was controlled by diffusion.Therefore，intensive stir diffusion could increase the indium leaching rate.