PROCESS FOR SEPARATION OF CRUDE TEREPHTHALIC ACID

摘要

Disclosed is a process for separation of crude terephthalic acid (CTA) by using a rotary pressure filter (RPF), in which said filter is divide into four functional sections, i.e. hydraulic filtering section, washing section by acetic acid, barometric filtering section and discharging section. Said hydraulic filtering section and said barometric filtering section are conducted at such a temperature and under such a pressure that crystallization on the filter cloth does not occur. The obtained filter cake with water content under 12wt% is dried. The ash as the impurity in the product is heavy metals and by-products of oxidation reaction and the content thereof is under 60ppm.