METHOD FOR PRODUCING GRANULATED SORBENT FOR EXTRACTION OF LITHIUM FROM LITHIUM CONTAINING BRINS UNDER CONDITIONS OF PRODUCTION OF COMMODITY LITHIUM PRODUCTS

摘要

In the proposed method, to obtain the sorbent in the form of a powder of LiCl2Al (OH) mHO (DGAL-Cl), a lithium-containing aluminum chloride solution is used. To obtain it, six-water aluminum chloride is dissolved in aqueous solutions containing both commodity lithium compounds: LiCl, LiOHHO, LiCO, and solutions containing them, coming from various stages of lithium production. The synthesis of DHAL-Cl is carried out at an atomic ratio of Al: Li in the reaction mixture equal to 2.0: 2.3. At the same time, sodium hydroxide solution was added to the reaction mixture to pH 7. The resulting DHA-Cl was separated by centrifugation, pulp in water, removing excess LiCl, and subjected to two-stage drying, first in a fluidized bed mode at t = 70-75 ° C, then vacuum drying at t = 60-65 ° C. A paste is prepared from the dried and ground powder by mixing DHAL-Cl with a previously prepared solution of polyvinyl chloride in an organochlorine solvent. As the solvent, both methylene chloride and trichlorethylene or tetrachlorethylene or mixtures thereof are used. The resulting paste is extruded through dies with a diameter of 5 mm with a countercurrent flow of heated air, freeing the extrudate from the organic solvent that evaporates into the air stream. After the stage of air degassing, the extrudate enters the stage of vacuum degassing. Next, the extrudate is subjected to crushing and classification with the return of the fine fraction to the preparation of the paste. Granules with a size of 1-2 mm are fed to drum rolling, giving them a rounded shape, the screening is sent to the preparation of the paste. Air cooled after degassing of the extrudate, saturated with vapors of an organochlorine solvent and water, is sent for compression at a pressure of 6 atm, while cooling the air stream to -3 ° C. The liquid phase formed during the condensation of the vapor of organochlorine solvents or their mixture and water is separated. The gas stream freed from the condensed phase is subjected to deep cooling to -15 ° C to deeply condense the vapors of the organochlorine solvent or a mixture of solvents and water vapors. The solid phase of ice is separated, and the liquid phase of the organochlorine solvent or solvent mixture is decompressed by heating to 0 ° C. With a deeper deposition to -70 ° C, the process of condensation of liquid phases from the air stream can be carried out in one stage. The liquid phase from the decompression and deep cooling operation is used in the paste preparation operation. The cleaned and drained air stream is heated to 120-140 ° C and used in the extrudate degassing operation.