Method for synchronously preparing magnesium metal and silicon/carbon through molten salt electrolysis

According to the method for synchronously preparing magnesium metal and silicon/carbon through molten salt electrolysis, a metal material serves as a cathode, calcium carbide or a silicon-calcium alloy serves as an anode, electrolysis is carried out in an MgCl2-NaCl-KCl-CaCl2-KF molten salt system, a final anode product is high-purity C or Si, and a cathode product is metal Mg; low-cost calcium carbide (CaC2) or silicon-calcium alloy (CaSi2) is used as an anode, and the chlorine evolution reaction is replaced by the oxidation of C2-or Ca, so that the problems of environmental pollution and subsequent chlorine treatment and utilization are solved, and the tank pressure (theoretical electrolytic tank pressure is 0V) is greatly reduced; meanwhile, high-purity C or Si left on the anode after electrolysis can be used as a high-added-value product and applied to the energy storage field of lithium ion batteries and the like; therefore, research and development of a novel magnesium electrolysis process of the CaC2 o