Patent / 1994
Process for simultaneous recovery of precious metals and tertiary phosphine from spent catalysts using tellurium
The org. or inorg. wastes are contacted with a solvent >120.degree., distd. to remove the lower-b.p. solvents and water, and then are contacted with Te (or a reducing Te compd.) with heating an refluxing to react with the precious metal for recovery. The high-b.p. solvent is preferably DMF suitable for fractional distn. at .ltoreq.150.degree.. After the sepn. of metal-Te complexes, the residual soln. is heated to recover the high-b.p. solvent, followed by sepn. of the tertiary phosphine as oxide by pptn. with water. The process is suitable for recovery of catalyst metals from spent hydrogenation catalyst typically contg. tris(triphenylphosphine)chlorerhodium or similar Rh compds.