Oxidative recovery of cobalt oxo catalysts

A process for demetalling an oxo product contaminated with cobalt-containing catalyst residues and recovering cobalt carbonyls therefrom which comprises:

• (a) treating the oxo product in a first demetalling zone with a first aqueous solution of a Co.sup.++ salt of an organic or inorganic acid to extract at least a portion of the cobalt-containing catalyst residues from the oxo product into a first aqueous phase and to form products including said Co.sup.++ salt and Co[Co(CO).sub.4 ].sub.2 therein;
• (b) substantially completing the demetalling of the thus treated oxo product by treatment in a second demetalling zone with an aqueous organic or inorganic acid in the presence of oxygen to form a Co.sup.++ salt of said acid;
• (c) contacting said first aqueous phase in an oxidation zone with molecular oxygen-containing gas at a temperature of from about 0.degree. to 90.degree. C. to form Co.sub.2 (CO).sub.8 in the presence of an organic solvent to extract said Co.sub.2 (CO).sub.8 and to thereby form an organic extract containing said Co.sub.2 (CO).sub.8 and an aqueous raffinate substantially free of Co.sub.2 (CO).sub.8 and containing dissolved Co.sup.++ acid salt values;
• (d) passing said organic extract to an oxo reaction zone as catalyst;
• and
• (e) contacting at least a portion of said aqueous raffinate with a higher molecular weight fatty acid, an organic solvent therefor and an alkaline reacting agent to form an organic phase containing the corresponding Co.sup.++ higher fatty acid salt suitable for recycle to an oxo reaction zone as catalyst.

The process for demetalling an oxo product contaminated with cobalt-containing catalyst residues and recovering cobalt carbonyls therefrom which comprises:

• (a) treating the oxo product in a first demetalling zone with a first aqueous solution of a Co.sup.++ salt of an organic or inorganic acid to extract at least a portion of the cobalt-containing catalyst residues from the oxo product into a first aqueous phase and to form products including said Co.sup.++ salt and Co[Co(CO).sub.4 ].sub.2 therein;
• (b) substantially completing the demetalling of the thus treated oxo product by treatment in a second demetalling zone with an aqueous organic or inorganic acid in the presence of oxygen to form a Co.sup.++ salt of said acid;
• (c) contacting said first aqueous phase in an oxidation zone with molecular oxygen-containing gas at a temperature of from about 0.degree. to 90.degree. C. to form Co.sub.2 (CO).sub.8 ;
• and
• (d) contacting the oxidized aqueous mixture of step (c) in a combined extraction/contacting zone with an organic solvent at elevated pressure in the presence of a higher molecular weight fatty acid and an alkaline reacting agent to extract said Co.sub.2 (CO).sub.8 into the organic phase and to form the corresponding Co.sup.++ higher fatty acid salt, thereby forming an organic extract phase containing said extracted Co.sub.2 (CO).sub.8 and said Co.sup.++ higher fatty acid salt suitable for recycle to an oxo reaction zone as catalyst.

The process for demetalling an oxo product contaminated with cobalt-containing catalyst residues and recovering cobalt carbonyls therefrom which comprises:

• (a) treating the oxo product in a first demetalling zone with a first aqueous solution of a Co.sup.++ salt of an organic or inorganic acid to extract at least a portion of the cobalt-containing catalyst residues from the oxo product into a first aqueous phase and to form products including said Co.sup.++ salt and Co[Co(CO).sub.4 ].sub.2 therein;
• (b) substantially completing the demetalling of the thus treated oxo product by treatment in a second demetalling zone with an aqueous organic or inorganic acid in the presence of oxygen to form a Co.sup.++ salt of said acid;
• and
• (c) contacting said first aqueous phase in a combined oxidation/contacting zone with molecular oxygen-containing gas at a temperature of from about 0.degree. to 90.degree. C. and in the presence of a higher molecular weight fatty acid, an organic solvent therefor, and an alkaline reacting agent to form an organic phase containing Co.sub.2 (CO).sub.8 and Co.sup.++ higher fatty acid salt corresponding to said higher fatty acid, said organic phase being suitable for recycle to an oxo reaction zone as catalyst.