| 摘要 |
In a process for the purification of waste gas containing CO2 and other acidic constituents, in particular SO2, in which the waste gas is scrubbed in an NH3-containing scrubbing solution, from which pollutants such as H2S, HCN and the like present in the starting solution have been substantially removed prior to feeding it to the scrubber, the pollutant-containing starting solution is treated in a stripping column in counter-current with a part-stream of at most 12% by volume, preferably 3 to 5% by volume, of the waste gas to be purified and the stripped solution is fed to a scrubbing tower as the scrubbing solution for the main quantity of the waste gas to be purified, while the pollutant-containing gases produced in the stripping column are fed to an incineration plant. The gases withdrawn from the stripping column can either be oxidatively combusted and the gas resulting from this passed into the scrubbing column or be subjected to combustion in a Claus plant or a plant for the production of H2SO4 or can be fed to coke-oven gas. A part-stream of the used scrubbing solution is oxidised with air with addition of NH3 in an oxidiser, and a part-stream of the oxidised solution is reacted with addition of lime to give calcium sulphate.
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