The invention discloses a method for hydrothermally recovering high-purity
terephthalic acid from printing and
dyeing white mud, which belongs to the technical field of
solid waste recycling in the
textile printing and
dyeing industry. The recovering method comprises the following steps of washing the alkali-decrement white mud by using a
dilute acid solution containing a surfactant, and then carrying out
solid-liquid separation to obtain a white mud
filter cake, dispersing the white mud
filter cake in water, adjusting the pH value, and carrying out a
hydrothermal reaction in a hydrothermal kettle, carrying out
solid-liquid separation on the hydrothermal product, and washing an obtained
filter cake by using a proper amount of pure water, and carrying out solid-liquid separation again, taking the solid, and
drying to obtain the high-purity
terephthalic acid. The pure
terephthalic acid recovered by the method has the
impurity content of less than 1.5% and the average grain size of more than 145 microns, and can be recycled for
polyester synthesis or
plasticizer synthesis, so that the printing and
dyeing white mud is economically and effectively recycled.