Selective extraction of lithium from clay minerals
Processes for extracting lithium from a clay mineral and compositions thereof are described. The extraction process includes providing a clay mineral comprising lithium, mixing a cation source with the clay mineral, performing a high-energy mill of the clay mineral, and performing a liquid leach to obtain a lithium rich leach solution.
1 . A process for extracting lithium from a clay mineral comprising:
performing a high-energy mill of a clay mineral comprising lithium;
forming a mixture comprising a cation source and the clay mineral concurrently with, before or after performing the high-energy mill, wherein the cation source comprises a cation and an anion; and
contacting the milled clay material and cation source with a solvent concurrently with or directly after forming the mixture and conducting a liquid leach at about 20-100° C. to form a lithium rich leach solution, wherein the lithium rich leach solution comprises:
lithium at a concentration of at least 100 ppm;
iron at a concentration of at most 10 ppm; and
aluminum at a concentration of at most 10 ppm;
wherein the anion of the cation source is selected from the group consisting of a halide, SO 4 2− , NO 3 − , and combinations thereof.
2 . The process of claim 1 , wherein the cation source is mixed with the clay mineral before performing the high-energy mill.
3 . The process of claim 1 , wherein the cation source is mixed with the clay mineral concurrently with performing the high-energy mill.
4 . The process of claim 1 , wherein the cation source is mixed with the clay mineral after performing the high-energy mill.
5 . The process of claim 1 , wherein the clay mineral comprises about 0.1-5 g of Li/kg of clay.
6 . The process of claim 1 , wherein the clay material further comprises one or more additional minerals selected from the group consisting of spodumene, lepidolite, zinnwaldite, smectite, hectorite, muscovite, and combinations thereof.
7 . The process of claim 1 , wherein the clay mineral comprises one or more additional elements selected from the group consisting of sodium, potassium, iron, aluminum, calcium, magnesium, silicon, chromium, and combinations thereof.
8 . The process of claim 1 , wherein the cation of the cation source is selected from the group consisting of an alkali metal, an alkaline-earth metal, and combinations thereof.
9 . The process of claim 1 , wherein the anion of the cation source is a halide.
10 . The process of claim 1 , wherein the cation source is selected from the group consisting of NaCl, KCl, Na 2 SO 4 , K 2 SO 4 , MgSO 4 , CaSO 4 , NaNO 3 , KNO 3 , CaCl 2 , MgCl 2 , Ca(NO 3 ) 2 , Mg(NO 3 ) 2 , and combinations thereof.
11 . The process of claim 1 , wherein the weight ratio of the cation source to the clay mineral is about 1:3 to about 1:50.
12 . The process of claim 1 , wherein the molar ratio of the cation of the cation source to lithium of the clay mineral is about 1:1 to about 10:1.
13 . The process of claim 1 , wherein performing the high-energy mill comprises using a high energy mill selected from the group consisting of a planetary ball-mill, an attritor mill, a high shear high energy mill, a vibratory mill, and combinations thereof.
14 . The process of claim 1 , further comprising pulverizing the clay mineral prior to performing the high-energy mill.
15 . The process of claim 1 , wherein the liquid leach is performed at about 20-90° C.
16 . The process of claim 1 , wherein a weight ratio of the mixture to the solvent is about 1:10 to about 3:10.
17 . The process of claim 1 , wherein the lithium rich leach solution comprises at least 150 ppm of lithium.
18 . The process of claim 1 , wherein the lithium extraction efficiency of the lithium rich leach solution relative to the clay mineral is at least about 50%.
19 . The process of claim 1 , wherein the lithium rich leach solution has a pH of about 5-10.
20 . The process of claim 1 , wherein a mixing solvent is provided to at least one of the clay mineral, the cation source, and the high-energy mill.
21 . The process of claim 20 , wherein the mixing solvent is the solvent.
22 . The process of claim 21 , wherein contacting the milled clay material and cation source with the solvent is performed directly after forming the mixture.
23 . The process of claim 21 , wherein contacting the milled clay material and cation source with the solvent is performed concurrently with forming the mixture.
24 . The process of claim 1 , wherein contacting the milled clay material and cation source with the solvent is performed concurrently with-forming the mixture.
25 . The process of claim 1 , wherein the milled clay material and cation source is a powder mixture.