RICUPERO DI RODIO DA CODA DI DISTILLAZIONE DI IDROFORMILAZIONE CON LEGANTE TRI-ARIL-FOSFITO.

摘要

A process for recovering rhodium present in a still heel from the hydroformylation of an unsaturated hydrocarbon wherein rhodium and a triaryl phosphite ligand were used by a process comprising… a) pretreating the still heel with a compatible organic solvent, at least 5 ml of water per 100 g of still heel, oxygen gas or a precursor thereof and sufficient base to produce a pH of 2 to 7 in the reaction mixture after rhodium precipitation;… b) heating to a temperature of from 0 DEG to 80 DEG C to oxidize the triaryl phosphite ligand to the corresponding phosphate compound;… c) heating the mixture from b) for from about 15 minutes to about 120 minutes at about 115 DEG C to about 175 DEG C to precipitate the rhodium and optionally purifying the rhodium from c) by… d) separating the rhodium precipitate;… e) washing the rhodium precipitate with a solvent-acid solution at a pH of 3 to 4;… f) treating the rhodium precipitate with an alkaline reducing solution to reduce the trivalent rhodium impurity to zero valent rhodium;… g) quenching the rhodium with glacial acetic acid;… h) separating the rhodium;… i) washing the rhodium with an acid solution at a pH of 3 to 4;… j) drying the rhodium in an inert atmosphere at from 250 DEG to 400 DEG C; and… k) oxidizing the rhodium at a temperature of from 300 DEG to 900 DEG C to convert the rhodium to Rn2O3.