METHOD FOR TREATING SEPARATED MOTHER LIQUOR FROM TEREPHTHALIC ACID REFINEMENT.

摘要

Provided is a method for treating the separated mother liquor from terephthalic acid refinement whereby recovered water with little impurity is obtained cheaply and in large quantity from the primary mother liquor separated at the time of primary crystallization. The method of treating the mother liquor (primary mother liquor) wherein the refined terephthalic acid crystals (primary crystals) and mother liquor (primary mother liquor) are separated from the crystal slurry involves an evaporation process wherein the aforementioned mother liquor is evaporated in the presence of terephthalic acid crystals by heating and flash evaporation at a pressure below atmospheric pressure and separated into vapor and a mother liquor suspension of terephthalic acid crystals; a process whereby terephthalic-acid-containing crystals are separated from the aforementioned mother liquor suspension; and a process whereby the aforementioned vapor is condensed and condensed water is produced.