METHOD FOR PRODUCING LITHIUM METAL AND INSTALLATION FOR ITS IMPLEMENTATION Russian patent published in 2021 - IPC C01D15/00 C22B26/12 C25C3/02 

FIELD: metallurgy.

SUBSTANCE: group of inventions relates to a method and apparatus for producing lithium metal. Method of producing lithium metal involves electrolysis of molten eutectic LiCl—KCl in cascade of parallel non-diaphragm electrolyzers with output of lithium metal electrolysers formed on cathodes, equivalent amounts of anhydrous lithium chloride are introduced into the anode region of the electrolysis cells and chlorine electrolysers are removed from the anode zones in the form of streams of chlorine-air mixtures which are combined into a common chloro-air stream. Chlorine-air stream is cleaned before release into the atmosphere by stepped contact of the combined chloro-air stream with chlorine absorbers. Electrolysis in non-diaphragm electrolyzers is carried out in mode of regular circulation of eutectic melt, preventing formation of stagnant zones on the surface of electrolyte melt, with uncontrolled accumulation of lithium metal in them. Circulation is provided by constant directed movement through melt of eutectic gaseous anode chlorine, achieved by shape and number of cathodes, arranged around anode block, in body of which channels for removal of anode chlorine are laid. Total chloro-air stream is first cleaned from the particles of the eutectic residue carried out from the electrolytic cell by counterflow contact with desalinated water spraying in the multistage hollow absorber to obtain an aqueous solution of LiCl + KCl salts. Solution is then dehydrated and, after correction of the composition, returned to electrolysis. Chloro-air stream cleaned from eutectics is separated by means of collector and shutoff-control gates into equal independent individual flows in amount equal to number of electrolytic cells in working stage. Each of the streams is separately directed into an individual gas-cleaning chain for operation of basic purification from chlorine by means of two-stage absorption in counter-circulating mode in dish-shaped absorbers. Passed basic purification from chlorine individual gas flows are combined again and supplied for sanitary treatment in a hollow scrubber with multi-tier irrigation using irrigating absorbents of initial solutions of LiOH or NaOH or (NH₂)₂CO or pulp Li₂CO₃, used after passage of sanitary treatment stage of combined gas flow as absorbents for basic cleaning operation in individual gas-cleaning chains.

EFFECT: technical result is elimination of risk of metal lithium production capacity decrease at failure of any of the used equipment elements, wider raw material base for lithium production.

6 cl, 9 dwg, 1 tbl