abstract |
A process is provided for the recovery and recycling of spent cobalt and/or manganese catalysts used in the air oxidation of alkyl aromatics in acetic acid. The catalysts are isolated in the form of oxalates of extremely low solubility from the acetic acid mother liquors and the cobalt oxalate dihydrate and/or manganese oxalate dihydrate catalysts are restored by the joint action of hydrogen bromide and acetic anhydride, acetyl bromide, or a mixture thereof, to a form in which they are soluble in acetic acid and can be used, again, as oxidation catalysts. |