METHOD FOR PROCESSING CONCENTRATED SOLUTION OF SODIUM SULFITE, SODIUM SULFATE AND SODIUM THIOSULFATE

摘要

A product liquor originating from flue gas desulphurisation is added into cooling water having pH lower than 1 and containing hydrochloric acid in a pre-washer of an apparatus for flue gas desulphurisation in a thermal power station using limestone (CaCO3) or lime (CaO), with the proviso that the product liquor is mixed with HCl-containing cooling water, the SO2 component is reacted in a manner known per se with limestone or lime to give processable gypsum (CaSO4.2H2O) and the HCl and NaSO4 components are reacted with slaked lime (Ca(OH)2) to give NaCl and gypsum.