块状低品位氧化锌矿浸出新技术研究

New Technology for Leaching of Low Grade Block Zinc Oxide Ores

针对氧化锌块矿直接柱碱浸时锌的浸出率偏低的问题,将块矿破碎到2mm以下,与5%的水泥混合,制粒并固化,得到直径在5～8mm之间的颗粒。固化3、10、45d的颗粒再进行浸出,锌的最大浸出率分别为91.6%(浸出7d内)、89.1%(浸出25d内)、76.4%(浸出25d内)。减少固化时间能够缩短反应时间、增加颗粒中锌的溶解以及减少浸出剂中初始锌浓度的影响。实验表明颗粒最少需固化3d。动力学研究表明,浸出过程受浸出剂通过脉石层的扩散控制,表观速率常数分别为3.33×10-2d-1、9.18×10-3d-1、5.82×10-3d-1。

Aiming at the problem of lower leaching rate of zinc when the block zinc oxide ores is leached directly by col- umn leaching, the block ore was crushed to below 2 mm, mixed with cement 5% （wt） , pelletized and solidified, then pellets with diameters between 5 mm to 8 mm are obtained. When the pellet solidification periods are 3 days, 10 days and 45 days respectively, the alkaline leaching rates of zinc in the pellets are up to 91.6% , 89.1% and 76.4% respec- tively. Decreasing the solidification time can reduce reaction time, increase dissolution of zinc in pellets and lower the effect of initial zinc concentration on leaching rate. The experiment results show that the minimum solidification time is 3 days, and the kinetic study indicates that alkaline leaching of the low grade zinc oxide pellets is controlled by the diffusion of the leach through the gangue layer in the whole leach process, and the apparent rate constants are 3.33×10^-2d^-1、9.18×10^-3d^-1、5.82×10^-3d^-1 respectively.