High-temperature electrochemistry of calcium

Abstract

Electrolytically produced calcium is one of the most demanded materials in obtaining pure materials. At the same time, the existing technologies and devices for the electrolytic production of calcium were developed in the last century, and at present there are practically no works aimed at optimizing them. However, increasing the capacity and efficiency of existing devices for the production of calcium is in demand. To analyze possible ways to improve calcium production, a comprehensive understanding of the processes occurring at the electrodes and in the electrolyte during electrolytic production of calcium is required. This review briefly outlines the main points concerning the electrolytic production of calcium: from a brief history of the development of methods for the electrolytic production of calcium and established ideas about its physicochemical processes to information about new developments using the electrolysis of CaCl<sub>2</sub>-based melts. Review content: brief history of process development; base electrolyte for calcium production, including preparation of CaCl<sub>2</sub> and influence of additions on it physicochemical properties; data on calcium solubility in CaCl<sub>2</sub>; information about alternative electrolytes for calcium production; short description of electrode processes in the CaCl<sub>2</sub>-based melts; proposed technologies and devices for the electrolytic production of calcium.