| 摘要 |
<p>Metal catalysts, e.g. copper and vanadium, employed in the nitric and oxidation step of adipic acid manufacture from cyclohexane are recovered by splitting the mother liquor stream remaining after the nitric acid oxidation step and filtration of adipic acid into a main stream and a purge stream, partial evaporation of the purge stream, dilution of the residue therefrom with water to a nitric acid content of 2% to 10% by weight, optionally cooling and filtering, contacting the acid solution with an ion exchange resin in the acid form, and recovering the metals from the ion exchange resin by elution with nitric acid. Suitable resins are in small particle (30-80 B.S.I. mesh) form and are sulphonated polystrene or styrene divinyl benzene copolymers. An example is given. Specification 572,260 is referred to.</p> |
