Patent ID: 9631256
Date: 2017-04-25
CPC Classifications: B01D,B09B,C01F,C22B

Claim:
1. A method for extracting alkali metal and/or alkaline earth metal from a solid, the method comprising: a first eluting the alkali metal and/or the alkaline earth metal by adding the solid to an amino acid-containing aqueous solution containing aspartic acid, thereby eluting the alkali metal and/or the alkaline earth metal in the amino acid-containing aqueous solution; precipitating the alkali metal and/or alkaline earth metal by contacting the amino acid-containing aqueous solution after the first eluting with an acid gas to precipitate the alkali metal and/or alkaline earth metal as a salt; collecting the salt; and a second eluting the alkali metal and/or the alkaline earth metal by further adding a solid comprising the alkali metal and/or the alkaline earth metal to the amino acid-containing aqueous solution after the collecting to elute the alkali metal and/or the alkaline earth metal into the amino acid-containing aqueous solution, wherein the precipitating comprises adjusting the pH of the amino acid-containing aqueous solution by adding a pH adjusting agent to the amino acid-containing aqueous solution before or after contacting with the acid gas to increase a pH value of amino acid-containing aqueous solution to 7 or more.