Preparation of lithium carbonate from lithium chloride containing brines

Abstract

This invention relates to a method for the preparation of lithium carbonate from lithium chloride containing brines. The method can include a silica removal step, capturing lithium chloride, recovering lithium chloride, supplying lithium chloride to an electrochemical cell and producing lithium hydroxide, contacting the lithium hydroxide with carbon dioxide to produce lithium carbonate.

1 - 30 . (canceled) 
     
     
         31 . A system for producing a lithium chloride-rich stream having a reduced concentration of boron from a Salton Sea geothermal brine, the system comprising:
 at least one intercalated lithium absorbent column configured to isolate lithium chloride adapted to:   remove lithium chloride from a stream of flashed Salton Sea geothermal brine, wherein the flashed Salton Sea geothermal brine has a reduced concentration of silica and iron, the concentration of the silica and iron having been reduced by oxidizing the flashed Salton Sea geothermal brine to precipitate silica and iron, wherein the concentration of the silica is less than about 25 ppm and the pH of the flashed Salton Sea geothermal brine is between about 4.5 and 6; and   be regenerated with wash water comprising lithium ions to produce a lithium chloride-rich stream having the removed lithium chloride; and   an ion exchange comprising a selective chelating ion exchange resin adapted to reduce the concentration of boron in the lithium chloride-rich stream.   
     
     
         32 . The system of  claim 31 , wherein the at least one intercalated lithium absorbent column comprises a lithium aluminum intercalate. 
     
     
         33 - 53 . (canceled) 
     
     
         54 . A system for producing a lithium chloride-rich stream having a reduced concentration of boron from a Salton Sea geothermal brine, the system comprising:
 at least one intercalated lithium absorbent column configured to isolate lithium chloride adapted to:   remove lithium chloride from a stream of flashed Salton Sea geothermal brine, wherein the flashed Salton Sea geothermal brine has a reduced concentration of silica and iron, the concentration of the silica and the iron having been reduced by oxidizing the flashed Salton Sea geothermal brine to precipitate silica and iron; and   be regenerated with wash water comprising lithium ions to produce a lithium chloride-rich stream having the removed lithium chloride; and   an ion exchange comprising a selective chelating ion exchange resin adapted to reduce the concentration of boron in the lithium chloride-rich stream.   
     
     
         55 . The system of  claim 54 , wherein the at least one intercalated lithium absorbent column comprises a lithium aluminum intercalate. 
     
     
         56 . The system of  claim 54 , wherein the concentration of the silica is less than about 25 ppm. 
     
     
         57 . The system of  claim 54 , wherein the concentration of the silica is less than about 5 ppm. 
     
     
         58 . The system of  claim 54 , wherein the pH of the flashed Salton Sea geothermal brine is between about 4.5 and 6. 
     
     
         59 - 85 . (canceled) 
     
     
         86 . A system for producing a lithium chloride-rich stream having a reduced concentration of boron from a brine, the system comprising:
 at least one intercalated lithium absorbent column configured to isolate lithium chloride adapted to:   remove lithium chloride from a stream of brine, wherein the brine has a reduced concentration of silica and iron, the concentration of the silica and the iron having been reduced by oxidizing the brine to precipitate silica and iron; and   be regenerated with wash water comprising lithium ions to produce a lithium chloride-rich stream having the removed lithium chloride; and   an ion exchange comprising a selective chelating ion exchange resin adapted to reduce the concentration of boron in the lithium chloride-rich stream.   
     
     
         87 . The system of  claim 86 , wherein the brine is a geothermal brine. 
     
     
         88 . The system of  claim 86 , wherein the brine is a Salton Sea geothermal brine. 
     
     
         89 . The system of  claim 86 , wherein the at least one intercalated lithium absorbent column comprises a lithium aluminum intercalate. 
     
     
         90 . The system of  claim 86 , wherein the concentration of the silica is less than about 25 ppm. 
     
     
         91 . The system of  claim 86 , wherein the concentration of the silica is less than about 5 ppm. 
     
     
         92 . The system of  claim 86 , wherein the pH of the brine is between about 4.5 and 6.