Process for the recovery of cobalt catalyst

Abstract

Abstract There is disclosed a cobalt catalyst recovery process which can provide substantially 100 percent recovery of cobalt from metaor para-xylene oxidation reaction products, in a catalytically active form relatively free from side reaction, tramp metal and corrosion products. The reaction medium, after recovery of isophthalic or terephthalic acid products, is distilled or flashed, diluted with water to achieve a cobalt concentration and acetic acid concentration sufficient to yield a pH of the solution above 3.0 and to precipitate iron and chromium values. The reaction medium is separated from these precipitates and treated with aqueous sodium carbonate which serves to convert the side reaction organic acids to soluble sodium salts and the cobalt to insoluble cobalt carbonate. Nickel impurities may be converted to a soluble form. The cobalt carbonate is separated out by filtration or the like, and is reconverted to cobalt acetate by treating the carbonate with acetic acid and, if desired, a minor amount of water. The catalyst solution, preferably after water removal, is recycled to the oxidation process.

Inventors

• 👤 Alvin E Trevillyan

Bibliographic Details