采用NaCl-CaCl2-Na2WO4体系熔盐电解制备金属钨粉,采用x射线衍射法(XRD)及能谱分析(EDS)表征电极产物并采用差热法(DTA)分析体系中发生的前置化学反应.采用循环伏安法和残余电动势法分析阳极过程和过电位变化规律.结果表明:800℃、槽电压2.5V条件下以石墨为电极可以电解制得钨粉,活性物质为电解前置反应产物CaWO4;阳极总反应不可逆,阳极过程为化学反应极化控制.
Tungsten powder was prepared in NaCl-CaCl2-Na2WO4 system by molten salt electrolysis method, chemical reactions occurred in electrolysis process, and electrolytic products were analyzed by means of X-ray diffraction ( XRD), scanning electron microscopy ( SEM), energy spectrum analyzer (EDS) and differential thermal analyzer (DTA). The anodic process and overvoltage were investigated using cyclic voltammetry and residual electromotive force method. The results show that tungsten powder could be synthesized under the conditions of a temperature of 800℃, a cell voltage of 2.5 V with graphite electrode, calcium tungstate is active substance in electrolysis process. The anodic reactions are irreversible and the kinetic obstruction of anodic process should be controlled by the anodic chemical polarization.