Separating rhodium from solution containing rhodium carbonyl complexes and converting the separated rhodium into soluble rhodium carbonyl complexes

A process for separating rhodium from solutions containing rhodium carbonyl complexes and products obtained in the carbonylation of alkanols or of olefinically or acetylenically unsaturated compounds with carbon monoxide and water, and converting the rhodium separated into a soluble rhodium carbonyl complex which comprises:

• contacting said solutions with hydrogen at a temperature of from 25.degree. to 300.degree. C. and at a pressure of from 1 to 700 atmospheres in the presence of a carrier such as is conventionally used for hydrogenation catalysts to precipitate the rhodium on the carrier;
• separating the solution devoid of rhodium;
• and
• contacting the rhodium precipitated onto the carrier with carbon monoxide in the presence of an aliphatic, cycloaliphatic or aromatic hydrocarbon, alkanol, ester, ether, ketone, amine or organic nitro compound as a solvent and in the presence of an olefinicably or acetylenically unsaturated hydrocarbon, organic compound of trivalent nitrogen, phosphorus or arsenic, ammonia, ammonium, phosphonium or arsonium salts or free halogen as a compound capable of replacing the carbon monoxide as a ligand at a temperature of from 20.degree. to 300.degree. C. and at a pressure of from 1 to 700 atmospheres whereby rhodium carbonyl complexes are reformed.