Process for preparing a concentrated solution of sodium sulphite and sulphate originating, in particular, from flue gas desulphurisation

摘要

The invention relates to a process for preparing a concentrated solution of sodium sulphite and sulphate (product liquor) originating, in particular, from flue gas desulphurisation. The characterising feature of the invention is that the product liquor is mixed with HCl-containing cooling water, the SO2 component is reacted in a manner known per se with limestone (CaCO3) or lime (CaO) 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. <IMAGE>