Method for recovering a metal from solution, system for recovering a metal from solution, and system for recovering lithium from salt water

Abstract

In a method for recovering a metal from a solution, a first electrode that includes a metal for recovery and a second electrode that includes a metal different from the metal for recovery are prepared. The first electrode and the second electrode are immersed in a first solution that includes a metal ion for recovery. The metal ion for recovery in the first solution is combined with the first electrode. The first electrode and the second electrode are charged while immersing the first and second electrodes in a second solution different from the first solution so that the metal ion for recovery is separated from the first electrode. The metal for recovery is recovered from the second solution.

What is claimed is: 
     
         1 . A method for recovering a metal from a solution, comprising:
 preparing a first electrode that includes a metal for recovery and a second electrode that includes a metal different from the metal for recovery;   immersing the first electrode and the second electrode in a first solution that includes a metal ion for recovery;   combining the metal ion for recovery in the first solution with the first electrode;   charging the first electrode and the second electrode while immersing the first and second electrodes in a second solution different from the first solution so that the metal ion for recovery is separated from the first electrode; and   recovering the metal for recovery from the second solution.   
     
     
         2 . The method of  claim 1 , wherein combining the metal ion for recovery in the first solution with the first electrode includes:
 electrically connecting the first electrode and the second electrode which are positively and negatively charged, respectively, to induce a discharge.   
     
     
         3 . The method of  claim 1 , wherein the metal for recovery includes lithium, the first electrode includes a lithium manganese oxide, and the second electrode includes at least one selected from the group consisting of silver, zinc, copper and mercury. 
     
     
         4 . A system for recovering a metal from solution, comprising:
 a first electrode including a first metal, the first electrode being discharged in a first solution that includes a first metal ion to be combined with the first metal ion and being charged in a second solution different from the first solution to release the first metal ion;   a second electrode including a second metal different from the first metal, the second electrode being discharged in the first solution to be combined with a first anion of the first solution and being charged in the second solution to release the first anion; and   a power source for charging the first and second electrodes.   
     
     
         5 . The system of  claim 4 , wherein the first electrode includes a lithium manganese oxide, and the second electrode includes at least one selected from the group consisting of silver, zinc, copper and mercury. 
     
     
         6 . The system of  claim 5 , wherein the first electrode includes LiMn 2 O 4  having a spinel phase. 
     
     
         7 . The system of  claim 5 , wherein the first electrode further includes a carbon electrode, and the lithium manganese oxide is coated on a surface of the carbon electrode. 
     
     
         8 . The system of  claim 4 , further comprising a battery capable of repeating charge and discharge processes,
 wherein an electric energy generated when the first and second electrodes are discharged is stored in the battery, and the battery is connected to the power source to provide the stored electric energy.   
     
     
         9 . A system for recovering lithium from a salt water, comprising:
 a first electrode including a lithium manganese oxide, the first electrode being discharged in a salt water that includes a lithium ion and a chlorine ion to be combined with the lithium ion and being charged in a charging solution different from the salt water to release the lithium ion;   a second electrode including silver, the second electrode being discharged in the salt water to be combined with the chlorine ion and being charged in the charging solution to release the chlorine ion;   a power source for charging the first and second electrodes; and   a battery capable of repeating charge and discharge processes, the battery storing an electric energy generated when the first electrode is discharged and being connected to the power source to provide the stored electric energy.   
     
     
         10 . The system of  claim 9 , wherein the first electrode includes LiMn 2 O 4  having a spinel phase.