Method for producing an adsorbent material and method for extracting lithium from saline solutions using the material

A method for preparing a crystalline solid material of formula (LiCl)x.2Al(OH)3,nH2O, wherein n is between 0.01 and 10, x is between 0.4 and 1, and wherein the method comprises:

• a) precipitating boehmite, in an aqueous medium, comprising bringing into contact at least one basic precursor and at least one acidic precursor, wherein at least one of the basic or acidic precursors comprises aluminum, in order to obtain a boehmite suspension, wherein the precipitation is carried out at a temperature of between 5 and 35° C., and the amount of the basic precursor is selected in order to obtain a pH of the end of precipitation in a reaction medium of between 7.5 and 9.5,
• b) bringing into contact the precipitate obtained in a) with at least lithium chloride (LiCl) as lithium source to form a suspension,
• c) filtering the suspension obtained in b) to obtain a paste,
• d) drying the paste obtained at the end of c) at a temperature between 20 and 80° C.,
• e) shaping the dried paste obtained in d) by acid extrusion-kneading, wherein the dried paste is kneaded in the presence of an amount of acid of between 0.05 and 5% by weight relative to dry material, wherein the dry material is the weight of the dried paste dried in an oven at 200° C., wherein the acid is an organic or inorganic acid, wherein the dried paste is then subjected to an extrusion, and the shaping the dried paste by acid extrusion-kneading is carried out in the absence of a binder, and
• f) drying the shaped dried paste obtained at the end of e) at a temperature between 20 and 200° C.