Method of preparing metallic lithium by one-step fusion electrolysis of lithium salt

Abstract

The invention discloses a method of preparing metallic lithium by one-step fusion electrolysis of lithium salt. The method comprises the following steps that: chlorine gas generated by a graphite anode (6) in an electrolytic bath is pumped to a high-temperature fusion chamber (11) of a decomposition groove on a reaction tank (13) by a chlorine gas feedback pipe (8), passes through a porous-titanium sieve plate (16) from bottom to top, and reacts with the fused alkaline lithium salt to generate lithium chloride for further electrolysis, and due to rapid reaction, the metallic lithium is generated continuously from bottom to top. The method disclosed by the invention has the advantages that the chlorine gas becomes a carrier for carrying lithium ions actually, circulates between a decomposition chamber and the high-temperature fusion chamber (11) in the electrolytic bath in a back-and-forth manner without being exhausted outwards, so that not only are the production efficiency and the quality of the metallic lithium improved, but also auxiliary equipment required for exhausting the chlorine gas outwards and the influence are avoided; in addition, due to the reduced processes about concentrated crystallization, centrifugal separation, high-temperature drying, lithium ingot fusion and vacuum distillation and the like, the procedure is obviously saved, the cost for the equipment and production is reduced and large business opportunity is brought for application of downstream processes and products.

Description

technical field [0001] The invention relates to the compound treatment technology related to international patent classification CO1D alkali metal lithium, especially the method for producing metal lithium by one-step molten electrolysis of lithium salt. Background technique [0002] Lithium is a soft, silver-gray, highly reactive alkali metal element. It has the lightest specific gravity among metals. Lithium is easily oxidized in air, so it must be stored in solid paraffin or inert gas. It can react with water and acid to release hydrogen, and is easy to combine with oxygen, nitrogen, sulfur, etc. The solubility of lithium salts in water is similar to that of magnesium salts, but different from that of other alkali metal salts. [0003] Lithium is abundant in nature, ranking 27th, and contains about 0.0065% in the earth's crust. Lithium exists widely in nature only in the form of compounds. There are more than 30 kinds of lithium minerals, mainly in spodumene (LiAlSi ...

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Problems solved by technology

[0008] The anhydrous lithium chloride used is the reaction of hydrochloric acid with alkaline lithium salt to generate a lithium chloride solution, and then the solution is evaporated and concentrated to crystallize at a high speed, and the crystallized lithium chloride is separated by centrifugation, and then put into a titanium high-temperature converter for drying. Lithium chloride is extremely corrosive and water-absorbent, and impurities are easily mixed in the production process. Therefore, the production process is complicated, the equipment requirements are high, and the cost is significantly higher than that of alkaline lithium salts. Therefore, general production enterprises are unable to produce metal lithium, which is also an important reason for the high price of metal lithium. At the same time, it further prevents the subsequent application cost from gradually decreasing for a long time, which limits the use of lithium in related industries. application

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