| 摘要 |
A process for recovering saturated aliphatic or cycloaliphatic dicarboxylic acids having from 5 to 10 carbon atoms (I) and polybasic carboxylic acids of the general formula II <IMG> ( II) where the A groups are each independently of the others a C1- to C4-alkylene group and n is from 1 to 4, by electrodialysis of aqueous solutions of salts or partial salts of these carboxylic acids comprises a) carrying on the electrodialysis until about 90% of the car boxylic groups are present in free form, b) separating the carboxylic acid from the resulting solution outside the electrodialysis cell as a whole or in part, and c) admixing the remaining solution with fresh salt and recircu lating it into the electrodialysis stage.
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