SEES THE COVEOXIDES LEFT FROM A COOXIDE-ALTIC GAS

摘要

REMOVAL OF NITROGEN OXIDES IN FORM OF AMMONIUM SULFATE FROM NITROGEN OXIDES-CONTAINING GAS A method of removing nitrogen oxides from a gas containing nitrogen oxides effectively in the form of ammonium sulfate, wherein a nitrogen oxides-containing gas is brought into contact with an aqueous solution which contains at least a ferrous salt and a sulfurous acid alkali salt to have the nitrogen oxides absorbed in the solution in the form of an alkali salt imidodisulfonic acid, and then the thus formed alkali salt of imidodisulfonic acid is converted into ammonium sulfate by hydrolysis at a temperature higher than 100.degree.C after separation and recovery of the salt from the solution.