FIELD: production of terephthalic acid. SUBSTANCE: method includes filtering of suspension and washing to separate liquid phase of carboxylic acid from solid material of terephthalic acid. Filtering and washing are carried out in body with gas medium which is also passed through cake on filter and may be recirculated after treatment for removal of impurities from it. To prevent repeated contamination of filter cake resulted from recirculating gas containing impurities entering the body, gas is introduced into body in point of cake output in direction opposite to direction of cake motion on moving filtering medium. In this way, such gradient of concentration of impurities is attained that the cleanest cake comes in contact with gas which contains minimum level of impurities. EFFECT: excluded contamination of terephthalic acid with solvent - acetic acid. 22 cl, 2 dwg
