Methods for treating lithium-containing materials

Abstract

The present disclosure relates to a method for treating an electromembrane process aqueous composition comprising sodium and/or potassium sulfate, said process comprising removing water from said electromembrane process aqueous composition under conditions suitable for substantially selectively precipitating sodium and/or potassium sulfate monohydrate.

What is claimed is: 
     
         1 . A method for treating an electromembrane process aqueous composition comprising sodium and/or potassium sulfate, said process comprising removing water from said electromembrane process aqueous composition under conditions suitable for substantially selectively precipitating sodium and/or potassium sulfate monohydrate. 
     
     
         2 . The method of  claim 1 , wherein water is removed by heating said electromembrane process aqueous composition at a temperature of about 100° C. to about 125° C. 
     
     
         3 . The method of  claim 1 , wherein water is removed by heating said electromembrane process aqueous composition at a temperature of about 100° C. to about 135° C. 
     
     
         4 . The method of  claim 3 , wherein said electromembrane process aqueous composition is heated at atmospheric pressure. 
     
     
         5 . The method of  claim 1 , wherein increasing concentration of said acid is carried out by a membrane dehydration process. 
     
     
         6 . The method of  claim 1 , further comprising carrying out a solid-liquid separation to recover said sodium and/or potassium sulfate, thereby obtaining said sodium and/or potassium sulfate and an acidic composition. 
     
     
         7 . The method of  claim 1 , further comprising carrying out a solid-liquid separation at a temperature of about 15° C. to about 130° C. to recover said sodium and/or potassium sulfate, thereby obtaining said sodium and/or potassium sulfate and an acidic composition. 
     
     
         8 . The method of  claim 1 , further comprising carrying out a solid-liquid separation at a temperature of about 25° C. to about 125° C. to recover said sodium and/or potassium sulfate, thereby obtaining said sodium and/or potassium sulfate and an acidic composition. 
     
     
         9 . The method of  claim 1 , further comprising carrying out a solid-liquid separation to recover said sodium and/or potassium sulfate, thereby obtaining said sodium and/or potassium sulfate and an acidic aqueous composition effective to be used for being mixed with an alkali-containing material. 
     
     
         10 . The method of  claim 1 , further comprising carrying out a solid-liquid separation at a temperature of about 15° C. to about 130° C. to recover said sodium and/or potassium sulfate, thereby obtaining said sodium and/or potassium sulfate and an acidic aqueous composition effective to be used for being mixed with an alkali-containing material. 
     
     
         11 . The method of  claim 1 , further comprising carrying out a solid-liquid separation at a temperature of about 25° C. to about 125° C. to recover said sodium and/or potassium sulfate, thereby obtaining said sodium and/or potassium sulfate and an acidic aqueous composition effective to be used for being mixed with an alkali-containing material. 
     
     
         12 . The method of  claim 1 , further comprising reusing the obtained sodium and/or potassium sulfate in said electromembrane process. 
     
     
         13 . The method of  claim 1 , wherein during said electromembrane process, pH of said sodium sulfate, potassium sulfate, sodium bisulfate and/or potassium bisulfate composition is acidic. 
     
     
         14 . The method of  claim 1 , wherein during said electromembrane process, pH of said sodium sulfate, potassium sulfate, sodium bisulfate and/or potassium bisulfate composition is basic. 
     
     
         15 . The method of  claim 1 , wherein said electromembrane process is an electrolysis process. 
     
     
         16 . The method of  claim 1 , wherein said electromembrane process is an electrodialysis process. 
     
     
         17 . The method of  claim 1 , wherein said aqueous composition comprises sodium sulfate. 
     
     
         18 . The method of  claim 1 , wherein said aqueous composition comprises potassium sulfate. 
     
     
         19 . The method of  claim 1 , wherein said aqueous composition consists essentially of sodium sulfate. 
     
     
         20 . The method of  claim 1 , wherein said aqueous composition consists essentially of potassium sulfate.