高硅低品位氧化锌矿的酸浸动力学

针对高硅天然氧化锌矿常规处理时存在的矿浆难压滤、液固比过小、Zn 浸出回收率低等问题, 试验探讨了酸度、加酸方式、固液比、粒度及温度因素对锌浸出率的影响。结果表明: 固液比1∶6时, 0.15～0.212 mm粒级在常温下与浓度为8%的H₂SO₄反应120 min, 锌的浸出率可达96.07%。升高温度, Zn的浸出率可提高至99.02%。浸出过程可用收缩未反应核模型来解释, 即浸出率与动力学方程1-(1-α)^1/3～ k·t 相吻合。浸出动力学显示反应过程中可通过控制矿物表层的扩散来控制反应过程的速率。活化能是控制扩散过程的特征, 其值约为6.385 kJ/mol。

Kinetics of Sulfuric Acid Leaching of High Silica Low-grade Zinc Oxide Ore

The effects of the acid value, acid ways, solid-liquid ratio, particle size and reaction temperature on the leaching rate of zinc have been investigated by experiments to solve the problems of difficult filter pressing pulp, low solid-liquid ratio and low leaching rate of Zn occurred while routine processing high silica natural zinc oxide ore. The results show that when the solid-liquid ratio is 1∶6 and the ores size is 0.15～0.212 mm react with  H₂SO₄ of which the concentration is 8% for 120 min at a normal temperature, the leaching rate of zinc can reach  96.07%. The leaching rate of zinc can increase by 99.02% while the temperature raised. The  leaching process can be explained by the model of  contractibility and unreacted core, that is the leaching rate conforms to the leaching  equation 1-(1-α)^1/3 ～ k·t. Leaching kinetics indicate that the rate of the reaction process can be controlled by controlling the diffusion of the mineral layer during the reaction. The activation energy is the character which control the diffusion process and the value of it is aproximately  6.385 kJ/mol.