(江西理工大學(xué) 材料與化學(xué)工程學(xué)院，贛州 341000)
摘 要: 通過熔鹽電解法從CaWO4-NaCl-CaCl2體系制備出金屬鎢粉，采用X射線衍射儀(XRD)、電子掃描顯微鏡(SEM)和能譜分析儀(EDS)對(duì)鎢粉的形貌和相組成進(jìn)行表征。在試驗(yàn)數(shù)據(jù)的基礎(chǔ)上計(jì)算電流效率，通過分析電解過程中形成的中間產(chǎn)物，討論電解過程中的電極反應(yīng)，采用循環(huán)伏安法和方波伏安法分析體系的基本熱力學(xué)性質(zhì)。結(jié)果表明：在750 ℃、槽電壓2.5 V下經(jīng)5 h以上電解可制備出純度達(dá)到99%、平均粒度低于2 μm的金屬鎢粉，實(shí)驗(yàn)中的電流效率可達(dá)到80%；電解過程的電極反應(yīng)不可逆，濃差極化是體系電解速率的主要阻力。
關(guān)鍵字: 鎢酸鈣；熔鹽電解；鎢粉；電極過程；濃差極化
（College of Materials and Chemical Engineering, Jiangxi University of Technology, Ganzhou 341000, China）
Abstract:Tungsten powders were prepared by molten salt electrolysis in CaWO4-CaCl2-NaCl system and its morphologies and phases composition were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and electron spectroscopy (EDS), respectively. The electrolytic efficiency was calculated based on experimental data. The electrode reactions during electrolysis were discussed by analyzing intermediate products formed in the electrolysis process. The thermodynamic properties of electrolysis process were studied by cyclic voltammetry and square wave voltammetry. The results show that tungsten powders can be prepared by electrochemical electrolysis under 750 ℃ with a cell voltage of 2.5 V for 5 h, which have a purity of 99% and particle sizes less than 2 μm, the current efficiency reaches 80%. The electrode reactions in the stable electrolysis region is irreversible and the concentration polarization process of cathode is an important factor of restricting electrolysis rate
Key words: calcium tungstate; molten salt electrolysis; tungsten powder; electrode process; concentration polarization
