氧化铌阴极微观结构对电脱氧制备铌的影响

The Influence of Cathode Microstructure on Production of Niobium Powder by Direct Electrochemical Reduction of Solid Nb_2O_5

采用电脱氧法,以Nb2O5烧结片为阴极,石墨棒为阳极,在CaCl2-NaCl混合熔盐中制备金属铌。分别研究了压制压力、烧结温度对阴极片微观结构和电脱氧反应及其产物的影响。实验结果表明,烧结温度和压制压力对Nb2O5烧结片的晶粒尺寸、孔隙度和孔隙尺寸具有明显的影响,从而影响到电脱氧的反应速率和效果。晶粒细、孔隙度高和连通性好的烧结氧化铌阴极能够提高电脱氧的反应速率和效果。研究表明,12MPa压制成型后经1 200℃烧结的阴极片,电脱氧效果最佳。

Sintered Nb2O5 powder compacts,used as the cathode while graphite rods as the anode,were electro-deoxidized in eutectic melt of CaCl2-NaCl.The influence of sintering temperature and compression load on the structure of cathodes,deoxidization and products was studied.The results showed that sintering temperature and compression load had great influence on particle size and porosity of sintered Nb2O5 powder compacts,and then affected the processing of electro-deoxidization.Fine particle size,high porosity and good connectivity will increase the rate and effect of electro-deoxidization.The optimum conditions were： compression load of 12MPa,sintering temperature of 1 200 ℃.