Membrane-based ion exchange system

Abstract

The presently disclosed concepts relate to improved techniques for critical mineral extraction, purification, precipitation, ion exchange, and metal production using a solid electrolyte membrane. By using a solid electrolyte embedded in a matrix, alkali metal (such as lithium) can be more effectively separated from feed solutions. Additionally, energy used to initially extract critical minerals from a feed solution may be stored as electrochemical energy, which in turn, may be discharged when critical minerals are depleted from the electrode. This discharged energy may therefore be reclaimed and reused to extract additional critical minerals.

What is claimed is: 
     
         1 . An ion exchange system, comprising:
 an anode;   a cathode, wherein the anode is configured for oxidation and the cathode is configured for reduction, and wherein migration of a predetermined alkali metal cation through a ion-selective solid electrolyte membrane is driven by a current across the anode and the cathode, wherein the ion-selective solid electrolyte membrane is selectively permeable to the predetermined alkali metal cation;   a first active material associated with the anode;   a second active material associated with the cathode;   an anolyte solution comprising the predetermined alkali metal cation and a first anion; and   a catholyte solution comprising the migrated predetermined alkali metal cation and a second anion, wherein the migrated predetermined alkali metal cation and the second anion are configured to combine to form a dissolved salt in the catholyte solution.   
     
     
         2 . The ion exchange system of  claim 1 , wherein the catholyte solution includes H 2 O or HCl. 
     
     
         3 . The ion exchange system of  claim 2 , wherein the H 2 O or the HCl is added at the same rate at which the predetermined alkali metal cation passes through the ion-selective solid electrolyte membrane. 
     
     
         4 . The ion exchange system of  claim 3 , wherein the catholyte solution comprises the H 2 O or the HCl as a reagent. 
     
     
         5 . The ion exchange system of  claim 1 , wherein the formation is based on a reduction of LiOH. 
     
     
         6 . The ion exchange system of  claim 1 , wherein the second anion comprises a hydroxyl group. 
     
     
         7 . The ion exchange system of  claim 1 , wherein the predetermined alkali metal cation comprises Li + . 
     
     
         8 . The ion exchange system of  claim 1 , wherein the first anion differs from the second anion. 
     
     
         9 . The ion exchange system of  claim 1 , wherein the first anion includes one or more of: CO 3   2− , HCO 3   − , NO 3   − , PO 4   3− , OH − , Cl − , Br − , or I − . 
     
     
         10 . The ion exchange system of  claim 1 , wherein the second anion includes one or more of: CO 3   2− , HCO 3   − , NO 3   − , PO 4   3− , OH − , Cl − , Br − , or I − . 
     
     
         11 . The ion exchange system of  claim 1 , wherein the anolyte solution and the catholyte each independently comprises a solvent comprising one or more of: water, alcohol, ester, ether, carbonate, or hydrocarbon. 
     
     
         12 . The ion exchange system of  claim 1 , wherein the first active material includes one or more of: H 2 , H 2 O, OH − , Cl − , Br − , or I − . 
     
     
         13 . The ion exchange system of  claim 1 , wherein the second active material includes one or more of: H + , H 2 O, O 2 , Cl 2 , Br 2 , or I 2 . 
     
     
         14 . The ion exchange system of  claim 1 , further comprising a buffer in one or more of the anolyte and the catholyte. 
     
     
         15 . The ion exchange system of  claim 1 , further comprising:
 a second ion-selective solid electrolyte membrane configured to selectively allow passage of the migrated predetermined alkali metal cation; and   a third solution comprising the allowed migrated predetermined alkali metal ion.   
     
     
         16 . The ion exchange system of  claim 15 , wherein the dissolved salt is an alkali metal salt, and a purity of the alkali metal salt in the catholyte is less than a purity of the dissolved salt in the third solution. 
     
     
         17 . The ion exchange system of  claim 16 , wherein the alkali metal salt is insoluble in the third solution. 
     
     
         18 . The ion exchange system of  claim 1 , wherein input energy used to migrate the predetermined metal alkali ion is saved and recovered, at least in part, as electrochemical energy of the migrated predetermined metal alkali ion at the cathode. 
     
     
         19 . The ion exchange system of  claim 18 , wherein the input energy corresponds with an electric charge process and the electrochemical energy corresponds with an electric discharge process. 
     
     
         20 . The ion exchange system of  claim 18 , wherein the recovery of the input energy reduces a carbon footprint of a manufacturing facility.