PROCESS FOR RECOVERING AND REUSING NICKEL, COBALT OR RHODIUM FROM MIXTURES CONTAINING CARBOXYLIC ACIDS

摘要

1. A process for the recovery of nickel, cobalt or rhodium from mixtures which contain aliphatic carboxylic acids of 3 to 10 carbon atoms, and are obtained by hydrocarboxylating olefins in the presence of a nickel-, cobalt-or rhodium containing catalyst, and the re-use thereof, wherein the carboxylic acids are substantially distilled off from the mixture in a thin-film evaporator at a temperature of from 100 to 200 degrees C and in a vacuum of 10 to 50 millibars, pure carboxylic acid is added to the bottom product containing the metal salts, and the resulting solution of the metal salts in the recycled acid is used again for a hydrocarboxylation.