Electrolyte for preparing calcium through fused salt electrolysis of calcium chloride, and electrolysis method using electrolyte

Abstract

The invention discloses an electrolyte for preparing calcium through fused salt electrolysis of calcium chloride, and an electrolysis method using the electrolyte. The electrolyte is prepared from the components in molar percentage: 5 percent to 20 percent of CaCl2, 10 percent to 20 percent of LiCl, 10 percent to 20 percent of KF, 5 percent to 10 percent of CaF2, and the balance KC1. The initial crystallization temperature and the density of the electrolyte adopting the component compatibilities can be greatly reduced, the density of the electrolyte can be controlled to be smaller than the density of fused calcium, and when the electrolyte is adopted for producing, the fused metal calcium obtained through electrolysis can be deposited onto a carbon cathode surface of a bottom layer of the electrolyte. When the fused salt calcium electrolysis production is carried out based on the electrolyte, a production mode of existing calcium electrolysis can be thoroughly changed, and the obtained metal calcium is collected to the bottom part of an electrolytic tank so as to be pumped out conveniently without the need for extra processing, so that the large-scale, continuous and energy-saving production of calcium electrolysis is realized.

Description

technical field [0001] The invention belongs to the technical field of electrolysis, and in particular relates to an electrolyte for producing calcium by electrolysis of calcium chloride molten salt and an electrolysis method using the electrolyte. Background technique [0002] The main means of industrial production of metallic high-purity calcium is calcium chloride molten salt electrolysis, and the methods used include contact cathode method and liquid cathode method. The traditional contact cathode method was first proposed by W. Rathenau in 1904, and the electrolyte used was CaCl 2 and CaF 2 composition of the mixture. The density of this molten mixture is much greater than that of molten salt calcium, so the electrolytic cell is designed so that the cathode is close to the upper part of the cell and the anode is at the lower part of the cell. It is less dense than molten calcium chloride and floats on the surface of the electrolyte, condensing on the cathode when in...

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Problems solved by technology

[0003] This method is the most direct method for producing high-purity calcium metal, but considering the reason of the electrolyte system used, the produced calcium metal floats on the upper part of the electrolyte. If no special treatment is carried out, the molten active calcium metal will quickly It will be oxidized, and even if the corresponding technology is adopted, the inherent defect of this method cannot be solved, that is, the problem that the produced metallic calcium floats on the electrolyte, thus causing the traditional contact cathode method to produce calcium with large raw material consumption and low output. , low current efficiency (serious secondary oxidation of calcium), high labor and cost, etc., and even gradually face to be replaced by liquid cathodic electrolysis

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