The invention belongs to the technical field of
molten salt electrolysis, and discloses a method for producing
calcium metal by performing electrodeposition and refining synchronously. According to the method, three stable liquid
layers with different densities are established in an
electrolytic cell, wherein the three stable liquid
layers respectively are light-phase
calcium-containing
molten salt of which the density is higher than
calcium metal, heavy-phase calcium-containing
molten salt of which the density is higher than the light-phase calcium-containing molten salt, and a molten calcium
alloy intermediate phase of which the density is between the density of the heavy phase and the density of the light phase; the molten calcium
alloy intermediate phase is taken as a bipolar
electrode, the side of the molten calcium
alloy intermediate phase, which is in contact with the heavy-phase calcium-containing molten salt is used as a
liquid cathode for dissolving calcium
metal generated by electrodeposition, and the side of the molten calcium alloy intermediate phase, which is in contact with the light-phase calcium-containing molten salt is used as a soluble
anode for precipitating element calcium out of the heavy-phase calcium-containing molten salt in the form of calcium metal at the
cathode. By adopting the method, the electrodeposition and refining of calcium metal are realized at the same time in one
electrolytic cell, and physical isolation of the heavy phase from the light phase as well as holding of impurities are realized through the intermediate phase, so that the purity of the finished product of calcium metal is improved.