Composition for recovery of lithium from brines, and process of using said composition
A solid particulate composition useful in extracting a lithium salt from aqueous solutions, the composition comprising lithium, metal atoms, oxygen atoms, and at least one anionic species (X) selected from halide, nitrate, sulfate, carbonate and bicarbonate, all in a framework structure, wherein said metal atoms are selected from at least one of oxophilic main group metal and oxophilic transition metal atoms, provided that, if the metal atoms comprise aluminum atoms, then at least 10 mol % of said aluminum atoms are substituted with at least one metal atom selected from said at least one oxophilic main group and oxophilic transition metal atoms, other than aluminum, and wherein said lithium is present in said composition in an amount less than a saturated amount in order to permit extraction of lithium salt. Methods for extracting and recovering a lithium salt from an aqueous solution by use of the above-described composition are also described.
1. A solid particulate composition useful in extracting a lithium salt from aqueous solutions, wherein the composition is a framework structure comprising LiX, M(OH) z units, and M′(OH) z units, wherein X is at least one anionic species selected from halide, nitrate, sulfate, carbonate, and bicarbonate; M is selected from aluminum, gallium, and indium; M′ is iron, and z is independently 2, 3, or 4, wherein M′ is present in an amount of at least 10 mol % of M but less than the molar amount of M.
2. The composition of claim 1 , wherein said at least one anionic species X is selected from halide atoms.
3. The composition of claim 1 , wherein said composition is represented by the following chemical formula:
LiX:M1 x-y M2 y (OH) 3 (1)
wherein X is at least one anionic species selected from halide, nitrate, sulfate, carbonate, and bicarbonate; M1 is at least one oxophilic main group metal atom selected from aluminum, gallium, and indium; and M2 is iron; x is at least 1 and up to 1.5; y is at least 0.1x and less than x; and the species Li, X, M1, and M2 in Formula (1) are within a framework structure.
4. The composition of claim 3 , wherein M1 comprises aluminum.
5. A method of extracting and recovering a lithium salt from an aqueous source solution containing said lithium salt, the method comprising:
(a) flowing said aqueous source solution containing lithium salt through a packed bed of solid particles having a composition that is a framework structure comprising LiX, M(OH) z units, and M′(OH) z units, wherein X is at least one anionic species selected from halide, nitrate, sulfate, carbonate, and bicarbonate; M is selected from aluminum, gallium, and indium; M′ is iron, and z is independently 2, 3, or 4, wherein M′ is present in an amount of at least 10 mol % of M but less than the molar amount of M, and wherein said lithium is present in said composition in an amount less than a saturated amount in order to permit extraction of said lithium salt from said aqueous solution containing lithium salt; and
(b) recovering lithium salt extracted in step (a) from said packed bed of solid particles by washing said packed bed of solid particles with an aqueous washing solution containing the lithium salt in a concentration of no more than 50% of the concentration of the lithium salt in the aqueous source solution containing the lithium salt, and wherein said aqueous washing solution is substantially bereft of metal ions other than lithium ions.
6. The method of claim 5 , wherein said composition is represented by the following chemical formula:
LiX:M1 x-y M2 y (OH) 3 (1)
wherein X is said anionic species; M1 is at least one oxophilic main group metal atom selected from aluminum, gallium, and indium; and M2 is iron; x is at least 1 and up to 1.5; and y is at least 0.1x and less than x; and the species Li, X, M1, and M2 in Formula (1) are within a framework structure.
7. The method of claim 6 , wherein M1 comprises aluminum.