电脱氧法制取金属铌的研究

Experimental Preparation of Niobium Metal by Electro-deoxidation

以Nb2O5粉末烧结片为阴极、石墨坩埚为阳极,在CaCl2-NaCl熔盐电解质中对Nb2O5阴极进行电脱氧,以制取金属铌。研究了Nb2O5粉末烧结阴极的制取,以及在熔盐电解质中电脱氧Nb2O5的工艺。研究结果表明,在熔盐电解质中电脱氧是通过熔盐电解质渗透到阴极片孔隙中,使Nb2O5粉末烧结片阴极形成良好的导电体,氧化铌被电离,氧离子通过熔盐电解质传导至石墨阳极坩埚,发生反应并以氧气析出。而阴极本身则发生铌离子还原,形成金属铌。研究表明,电脱氧速度和电脱氧效率与电解质与氧化铌接触面大小和电解温度有关,渗透性好、孔隙度高即接触面大的阴极片和高的电解温度将有较高的电脱氧速度和效率。

Nb2O5 was electrodeoxidized in a eutectic melt of Ca-Cl2-NaCl with a sintered Nb2O5 powder compact as the cathode and a graphite cup as the anode to prepare niobium metal. The technology for the making of the cathode and eleectrodeoxidation of Nb2O5 was studied. The results show that the electrodeoxidation is achieved through the impregnation of the eutectie melt into the pores of the sintered cathode. Thus, an excellent conductor is formed and Nb2O5 is ionized. At this time, the ions are transferred to the cathode through the eutectic melt to the graphite cup, reacting with it, and then releaseas oxygen gas. Finally, the cathode is reduced to form niobium metal. The results indicate that the rate of eleetrodeoxidation depends on the contact area between the melt and Nb2O5 and the temperature of electrodeoxidation. The more pores and better impregnation, the higher the rate of electrodeoxidation.