APPARATUS AND METHOD OF PURIFYING ISOPHTHALIC ACID BY MULTISTAGE LEACHING

摘要

PURPOSE: An apparatus and a method for purifying isophthalic acid are provided to produce high purity of isophthalic acid of 99.9% or more, to recover an extraction agent, to simplify a process, and to reduce energy. CONSTITUTION: An apparatus for purifying isophthalic acid for removing impurities from crude isophthalic acid raw materials containing acetic acid, 3-carboxybenzaldehyde, meta-toluic acid, and benzoic acid comprises: a multi-stage solid/liquid extractor(1) for eliminating impurities by mass transfer; a product dryer(2) for producing isophthalic acid products of high purity by drying solid isophthalic acid containing an extraction agent; an evaporator(3) for solvent recovery, which discharges isophthalic acids, 3-carboxybenzaldehyde, meta-toluic acid, and benzoic acid form impurities; and a distillation column(14) for recovering an extraction agent.