以Nb₂O₅粉末烧结片为阴极，以石墨为阳极，在CaC1₂NaCl熔盐电解质中对Nb₂O₅进行电脱氧，获得金属铌.对不同密度的Nb₂O₅粉末烧结阴极的制取以及烧结阴极密度对电脱氧Nb₂O₅的影响进行研究.结果表明，阴极片的烧结密度对Nb₂O₅在CaC1₂-NaCl熔盐中的电脱氧有着极其重要的影响，烧结密度越低，电解起始电流越大，并且在电脱氧过程中电流也越大；在相同电解时间内，阴极产物中残余氧化物化合价随阴极片密度的降低而降低；Nb₂O₅粉末在8 MPa压力下成型，1 150 ℃下烧结8 h，所得的阴极片具有较好的电化学活性；在850 ℃下电解150 min，Nb₂O₅可完全被还原；电脱氧反应速度会随电解时间的延长而逐渐减慢.实验结果表明，电脱氧是氧化物粉末颗粒与熔盐电解质接触、反应和电离的过程，Nb₂O₅的电脱氧过程是分步进行的，其中间产物是铌的一系列低价氧化物，即Nb⁵⁺→Nb⁴⁺→Nb²⁺→Nb.

A novel technique of electrodeoxidation was studied for preparation of metal niobium. Nb₂O₅ was electrodeoxided in a eutectic melt of CaC1₂-NaCl with a sintered compact as a cathode and graphite as an anode. Nb₂O₅ cathodes with different density were prepared by sintered and influence of density of the cathodes on electrodeoxidation was investigated. The results show that density of sintered Nb₂O₅ cathodes has important effect on electrodeoxidaion of Nb₂O₅ in a eutectic melt of CaC1₂NaCl. The lower the density of sintered Nb₂O₅ cathode, the larger the electricity is started at the beginning of and during electrodeoxidation. Valence of the residual oxide niobium in the same time of electrolysis was lowered with decrease of the density of sintered Nb₂O₅ cathode. It had better electrochemistry activity and was reduced by electrolysis at 850 ℃ for 150 minutes for the sintered Nb₂O₅ cathode prepared under the condition of compaction of Nb₂O₅ powder at 8 MPa pressure and sintering at 1 150 ℃ for 8 hours. The reactive rate of electrodeoxidation gradually became low with increasing electrolyzing time. The experiment indicates that electrodeoxidation is a process of interconnection between electrolyte and oxide powder particle, and between reaction and ionization. The electrodeoxidation reaction of oxide niobium is a step-by-step progress from high valence to low valence and to pure metal, i.e. Nb⁵⁺→Nb⁴⁺→Nb²⁺→Nb.