DESULPHURIZATION OF FLUE GASES

摘要

In the method proposed, the flue gases are scrubbed (3) with a solution containing an alkali. The scrubbing solution is then purified, before or after an oxidation stage (4), in an operation (6) comprising a combination of sedimentation and membrane filtration. At least a part of the solids in the concentrate obtained from the membrane filtration is separated off by sedimentation and the remaining liquid fed back to the membrane-filtration process and hence into the main circuit, and the alkali-metal sulphate crystallized out. A pure-white alkali-metal sulphate free of dark-coloured impurities is thus obtained inexpensively.