EXTRACTANTS FOR PALLADIUM AND PROCESS FOR SEPARATION AND RECOVERY OF PALLADIUM

摘要

The invention provides novel extractants for palladium which bring about enhancement in the extraction speed as compared with the extraction with DHS (which is one of the current extractants) and a process for the separation and recovery of palladium with the same, particularly, a process which comprises extracting palladium into an organic phase consisting of a sulfur-containing diamide represented by the general formula (1) by the contact with palladium with the organic phase and subjecting the obtained palladium-containing extract to back extraction with an aqueous hydrochloric acid solution containing thiourea to obtain an aqueous solution containing palladium: (1) wherein R₁ and R₂ are each a group selected from among C_1-18 chain hydrocarbon groups (which may be branched), C_1-10 alicyclic hydrocarbon groups, and C_1-14 aromatic hydrocarbon groups; and R₃ is a {(CH₂)_nS(CH₂)_m}_L group (wherein n, m, and l are each an integer of 1 to 4).