Process for treating waste waters from flue gas desulphurisation plants

摘要

In the flue gas desulphurisation by scrubbing the flue gas with circulating calcium oxide- or calcium hydroxide-containing scrubbing liquids, waste waters (effluents) are produced both in the drying of the resulting gypsum and in the excess scrubbing liquid. It is proposed not to discharge at least some of these scrubbing waters, but to bring them in contact with the flue gas or a part of the flue gas and thus to evaporate all or some of the waste waters. In this case, organic constituents, which are desired there, return via the flue gas into the scrubbing water circulation, while constituents undesirable there, in particular inorganic constituents, chiefly calcium chloride, remain as solids.