铁酸锌的还原分解和其中锗的行为研究

STUDIES ON REDUCING DECOMPOSITION OF ZINC FERRITE AND THE BEHAVIOR OF GERMANIUM IN THE PROCESS

在湿法炼锌中生成难溶性的铁酸锌是锌、锗浸出率低的原因。采用还原沸腾焙烧锌焙砂的工艺可有效地把铁酸锌还原分解成可溶性的产物,赋存其中的锗也将大部分溶出。本文研究了锌焙砂的物相组成,对铁酸锌还原过程的热力学、动力学进行了分析和研究。从而确定了铁酸锌还原分解的工艺条件并查明锗在工艺中的行为。在800—860℃,CO 8—12％的条件下对锌焙砂还原焙烧20—40min使锌浸出率从87％提高到98.5％,锗浸出率从47％提高到85—90％。研究证实了还原分解铁酸锌工艺的可行性。

In zinc hydrometallurgy, the formation of insoluble zinc ferrite (ZnFe_2O_4) results in low leaching rate of zinc and germanium. The zinc ferrite can be effectively decomposed into soluble products in the reduction process of fluidized- bed roasting of zinc calcine. Thus, the germanium existing in ZnFe_2O_4 can mostly dissolve out. Based on the investigation of mineralogical composition of zinc caline and studies on thermodynamics and kinetics of ZnFe_2O_4 in the reduction roasting, the technical conditions of reduction roasting process are established, the Ge behavior in the process is revealed as well. The Zn leaching rate is raised to 98.5% from 85% and Ge to 85-90% from 47% after the zinc calcine is roasted under the conditions of t=800-860℃, CO 8-12% and time 20-40min. It is confirmed that the reducing decomposition process of zinc ferrite is feasible.