method for reducing oxidation of the amp; darr; 2 amp; darr; waschprozeß incidental case amp; darr; 3 amp; darr; sludge

摘要

The parent application described washing SO2 contg. waste gases with a liquid contg. carboxylic acid and additives, and oxidising with air in a separate vessel for several minutes. In this Patent of Addn. the oxidn. time is shortened by using a wash soln. contg. carboxylic acid or its salt which is enriched in CaCl2, the concn. being 5 wt.% CaCl2. Air is introduced immediately after the soln. has contacted the waste gas. The method is more economical as oxidn. time is shortened and an oxidant may not be required depending on the size of the desulphurising plant for the waste gas.