(江西理工大學(xué) 冶金與化學(xué)工程學(xué)院，贛州 341000)
摘 要: 采用循環(huán)伏安法、計(jì)時(shí)電流法、計(jì)時(shí)電位法研究以MgO為原料、LiF-MgF2-BaF2-KCl為電解質(zhì)體系、溫度為1173 K時(shí)鎂離子在鎢電極上的電化學(xué)還原過程。結(jié)果表明：鎂離子在鎢電極上的電化學(xué)還原是一步轉(zhuǎn)移兩個(gè)電子的過程，電極反應(yīng)為Mg2++2e→Mg；鎂在鎢電極析出過程中出現(xiàn)成核極化現(xiàn)象，析出過程是受擴(kuò)散控制的不可逆反應(yīng)；1173 K時(shí)，Mg2+在熔鹽中的擴(kuò)散系數(shù)D為1.28×10-5 cm2/s。
關(guān)鍵字: 氧化鎂；熔鹽；電化學(xué)還原；擴(kuò)散控制
（School of Metallurgical and Chemical Engineering,
Jiangxi University of Science and Technology, Ganzhou 341000, China）
Abstract:The electrochemical reduction mechanism of Mg2+ on the tungsten electrode at 1173 K was studied through the methods of cyclic voltammetry, chronopotentiometry and chronoamperometry using MgO and LiF-MgF2-BaF2-KCl as raw material and molten salt. The results show that the electrochemical reduction of Mg2+on the tungsten electrode is a two-electron transition process by one step. The electrode reaction is Mg2++2e→Mg. During depositing process, the nuclear polarization phenomenon is observed. The depositing process of Mg is an irreversible reaction controlled by diffusion, and the diffusion coefficient of Mg2+ in the molten salt is 1.28×10-5 cm2/s at 1173 K.
Key words: magnesium oxide; molten salt; electrochemical reduction; diffusion control
