摘要 |
A compsn. comprises a mixt. of at least 3 different diketones of the formula:- In (I) R1 is methyl or 2-6C alkyl or alkenyl; R2, R3 and R4 are H, methyl or 2-3C alkyl or alkenyl; Y represents identical or different substituents chosen from H, Cl and F; pref. H; the sum of the C atoms(n) of R1 R2 R3 and R4 can amt. to 6 for each cpd. but the fraction in which n is 2-4 comprises at least 60%, pref. at least 70% of the mixture. The mixture is used, optionally in an inert water-insoluble solvent, to extract metals from aq. soln; the organic extract sepd is heated with acids to recore the metal. Metals extracted are Cu, Co, Ni, Fe, Ag, Be, Ga, Eu, In, Zn. The use of the mixture improves the solubility of the cpds. in organic solvents and gives a greater extraction capacity. |