难选氧化锌矿氨浸过程热力学分析

针对难选氧化锌矿的特点，对氧化锌矿氨浸过程进行热力学分析。氧化锌的氨浸可能发生氨水与氢离子的反应，锌离子和氢氧阴离子的络合反应，锌离子与氨水的络合反应。溶液中无氨存在时，Zn^2 与OH^-的配合反应可以忽略。氧化锌在氨水溶液中的溶解度随氨水浓度和pH的变化而变化，而当溶液氨浓度为4mol／L时，总锌浓度Zn]T保持在1mol／L左右。以4mol／L的氨水溶液浸出兰坪难选氧化锌矿38min，锌浸出率达81．89％。

Thermodynamics on Ammonia Leaching of Refractory Zinc Oxide Minerals

The ammonia leaching process of zinc oxide is thermodynamically analyzed based on the feature of refractory zinc oxide minerals. The reactions occurring in ammonia leaching of zinc oxide are ammonia hydration, zinc ion complex with hydroxyls, and zinc ion complex with ammonia. While there is no ammonia in the solution, the reaction of zinc ion complex with hydroxyls can be neglected. The solubility of zinc oxide is varied with the changes of the ammonia concentration and the pH, however, the total zinc concentration in solution is maintained about 1mol/L as long as the ammonia concentration is higher than 4mol/L. The leaching recovery of zinc is up to 81.89% for refractory zinc oxide minerals from Lanping Deposit by ammonia leaching with 4mol/L of ammonia solution for 38min.