Electrochemical Dissolution Process of Tungsten Carbide in Low Temperature Molten Salt System

Abstract

Tungsten was extracted from LiCl-KCl-Li2WO4 molten salt with tungsten carbide as soluble anode, and its electrochemical dissolution was studied. Although the fused salt electrochemical method has the advantages of short process and easy equipment operation, the current electrolysis process faces problems such as higher electrolysis temperature, high energy consumption, and complex composition of the products. Therefore, in this study, in order to reduce the electrolysis temperature and energy consumption, tungsten was extracted by LiCl-KCl-Li2WO4 molten salt system in the temperature range 400 °C–600 °C. In addition, compared to the blank salt electrolysis, the addition of Li2WO4 as the active material facilitated the reaction and improved the dissolution efficiency, and the current efficiency. Through a series of electrochemical tests, it is proved that the adding of Li2WO4 decreases the charge transfer resistance and speeds up the reaction. Moreover, the oxidation–reduction process of tungsten ion in tungstate was investigated, indicating that the redox process is a reversible process controlled by diffusion. Clusters of spherical tungsten powders were prepared at 500 °C by optimizing the experimental parameters.