熔盐电脱氧法制备金属Cr粉的研究

RESEARCH OF PREPARATION OF Cr BY ELECTRODEOXIDATION IN MOLTEN SALT

以烧结的Cr2O3片体为阴极、高密度石墨碳棒为阳极,在820℃的CaCl2熔盐中,2.8V电压下进行电脱氧反应,制得金属铬。研究了烧结温度、电解时间对电解反应的影响,用电子扫描显微镜(SEM)分析了900℃、1200℃烧结试样电解前后的微观形貌;XRD分析了电解产物的相组成。结果表明:试样的烧结温度越高,孔隙率越低,电脱氧反应速率越慢,产物的颗粒越大;电解还原是从外向内进行的;扩散过程是影响电脱氧反应速率的重要因素。

Metallic Cr was prepared by electrodeoxidation from Cr2 03 in molten CaCl2 at 820℃ under a voltage of 2.8 V. During electrolysis Cr2O3 pellets sintered at different temperature were used as cathode,while high density graphite rod was used as anode. The effect of sintering temperature and the time of electrolysis on the process was investigated. The microstructure of the Cr2 03 pellets before and after sintering was investigated by SEM. The phase composition of products electrolysed under different conditions were examined by XRD. The resuits show that the higher the sintering temperature, the lower the porosity, the lower the speed of electro-deoxidation and the larger the grain of product is. Cr2O3 was reduced step by step from outside to inside. The diffusion plays an important role on the reductive process.