(上海大學(xué) 材料科學(xué)與工程學(xué)院，上海 200072)
摘 要: 采用固體透氧膜(SOM)法直接電解還原Nb2O5制備金屬Nb。在CaCl2熔鹽體系中，電解電壓控制為3.2 V，以經(jīng)過(guò)1 200 ℃預(yù)燒4 h成型的Nb2O5為陰極，氧化鋯管內(nèi)碳飽和的液態(tài)銅合金為陽(yáng)極。研究電解時(shí)間分別為0.5、1、2和4 h以及不同溫度下電解的特征規(guī)律和不同電解溫度對(duì)陰極產(chǎn)物微結(jié)構(gòu)的影響。結(jié)果表明：隨著電解的進(jìn)行，Nb2O5首先轉(zhuǎn)變?yōu)镹b的一系列低價(jià)氧化物，進(jìn)而才被還原成金屬Nb；且隨著實(shí)驗(yàn)溫度的升高，電解速度相應(yīng)加快，金屬鈮顆粒尺寸增大。與FFC法相比，SOM法具有更高的電解效率，1 150 ℃下的電解效率可達(dá)81.7%。
關(guān)鍵字: 固體透氧膜；Nb2O5；Nb；電化學(xué)；還原
（School of Materials Science and Engineering, Shanghai University, Shanghai 200072, China）
Abstract:Niobium was produced directly from Nb2O5 using solid oxygen-ion membrane (SOM). In molten flux CaCl2 system, electrolysis voltage is 3.2 V, Nb2O5 pellets preformed and sintered at 1 200 ℃ for 4 h and liquid metal saturated with carbon loaded in zirconia tube act as the cathode and anode, respectively. The electrochemical character of electrolytic process and the micro-structural features of the cathode pellets were studied at different temperatures for 0.5, 1, 2 and 4 h, respectively. The results show that Nb2O5 is transformed to a series of low value oxides firstly, and then proceed to the metal Nb with electrolysis. The electrode reaction rate and the grain of reduced metal increases with temperature increasing. SOM process has higher electrolysis efficiency comparing with FFC process. The electrolysis efficiency can be as high as 81.7%.
Key words: solid membrane; Nb2O5; Nb; electrochemistry; reduction
