低品位氧化锌矿在NH_3-NH_4HCO_3-H_2O体系中的浸出动力学研究(英文)

Leaching Kinetics of Low-Grade Zinc Oxide Ores in NH_3-NH_4HCO_3-H_2O System

对高钙低品位氧化锌矿在NH3-NH4HCO3-H2O体系中的浸出动力学进行了系统研究.研究结果表明,氧化锌矿浸出过程遵循"未反应核缩减"模型,即遵循动力学方程:1-(1-α)1/3=k.t.反应的表观活化能Ea=6.489 kJ/mol,浸出过程由外扩散过程控制.增强搅拌强度、提高总氨浓度及反应温度均可加快该矿石中锌的浸出速率,并在一定范围内提高锌的浸出速率.

In this study,the leaching process of high calcium and low-grade zinc oxide ores in NH3-NH4 HCO3H2 O system is investigated.It is shown that the leaching process of the zinc ores in the NH3-NH4HCO3-H2O system follows the shrinking unreacted core model,which can be described by the kinetic equation,i.e.1-（1 α） 1 /3 = k.t.The apparent activation energy of the leaching reaction of 6.489 kJ /mol is also obtained.The leaching process is controlled by external diffusion.It is also shown that both the leaching rate and the leaching velocity can be improved with increased stirring intensity,total ammonia concentration and reaction temperature.