Removal of sulphur oxide cpds. from waste gases - by contact with soda slag from metal desulphurisation

摘要

Desulphurisation of waste gases contg. S oxides (esp. SO2) is carried out using a desulphurising agent comprising the soda slag formed during the desulphurisation of metal melts with Na2CO3 (e.g. in a blast furnace). Process for combatting water pollution by Na salts of sulphur oxyacids (esp. the Na2SO4 formed above) comprises adding the Na salts to an aq. Fe2(SO4)3 soln. at 50-90 degrees C, thereby forming an insoluble ppte. The two processes A and B can be integrated to combat air pollution by SO2-contg. waste gases (e.g. from iron ore briquetting units), water pollution by the Na2SO4 formed with the first, and also water pollution by FeSO4 formed by picking rolled steel sheets with H2SO4, since the FeSO4 can be oxidised to Fe2(SO4)3 for use in the second process.