Method for preparation of the granulated sorbent for recovering lithium from lithium-containing brines

A method for obtaining a granulated sorbent for lithium recovery from lithium-containing brines, the method comprising:

• obtaining a chlorine-containing modification of aluminum lithium double hydroxide (DHAL-Cl) from a solution of aluminum chloride with an AlCl3 concentration of 45-220 kg/m3, comprising lithium with an atomic ratio of Al:Li of 2.0-2.3:1, with addition of sodium hydroxide to the pH of the mixed solution,
• characterized in that
• the pH of the mixed solution is 4-5,
• instead of separating the obtained DHAL-Cl slurry from the reaction mixture followed by its drying, the DHAL-Cl slurry is mixed with the polyvinyl alcohol aqueous solution in an amount of 10-15 wt. % (in terms of polyvinyl alcohol) by weight of LiCl·2Al(OH)3,
• well stirring the mixture at a temperature of 60-80° C. until a smooth mass is obtained,
• drying the resulting mixture to a paste-like state and extruding,
• pelletizing the extrudate forming a rounded (spherical) shape of the granules,
• heat-treating the granules at 105-120° C. for 12-24 hours to form an insoluble carbon frame of the sorbent having a uniformly black color;
• washing the granulated sorbent with water prior to its use for lithium sorption, to remove sodium chloride.