A METHOD FOR EXTRACTING LITHIUM

Claims

The present invention pertains to the technical field of lithium purification and relates to a method for extracting lithium. It uses an extraction system containing a diketone compound as the extractant, and the diketone compound has the general formula indicated as formula (1); wherein, n = 0, 1 or 2, R1, R2, R3 and R4 are independently selected from C1-C8 alkyl, C6-C12 phenyl, C6-C12 substituted phenyl, C6-C20 aryl, C6-C20 substituted aryl or C6-C20 heteroaryl, R1, R2, R3 and R4 are the same or different; R1, R2, R3 and R4 satisfy the following conditions: when n = 0, R1 has at least one hydrogen atom on the carbon atom connected to the carbonyl group, and / or R2 has at least one hydrogen atom on the carbon atom connected to the carbonyl group; when n = 1 or 2, the total number m of hydrogen atoms on the carbon atoms in R1, R2, R3 and R4 connected to the carbonyl group satisfies: 2 ≤ m ≤ 8.The diketone compound of the present invention can control the degree of single-molecule enolization and perform partial enolization, which can reduce dissolution loss and alkali consumption, and has a high extraction rate and lithium selectivity.