| abstract |
In pretreating a pyridine ring-containing chelate resin which is used in the step for adsorption and collection of a heavy metal ion and a bromide ion derived from a catalyst from the oxidation reaction mother liquid in the process of producing an aromatic carboxylic acid, there may occur phenomena such as swelling of the resin, heat generation of the resin, and air bubbles generation, thereby causing fracture and deterioration of the resin. As a first treatment, Br − conversion, under a certain condition, of a pyridine ring-containing chelate resin with an aqueous solution of hydrobromic acid is performed, and then as a second treatment, replacement with acetic acid solvent is performed, thereby making it possible to prevent fracture and deterioration of the resin. |