METHOD FOR REMOVING POLLUTANT SUBSTANCES FROM LEAVING GASES Russian patent published in 2018 - IPC B01D53/14 B01D53/56 

FIELD: technological processes.

SUBSTANCE: invention relates to a method for removing contaminants from effluent gases, arising from etching operations in the purification of metallurgical components or sheets. Method comprises introducing a measured amount of gaseous oxygen into a pickling solution in a metal etching operation, where oxygen oxidizes the reaction products of nitric acid and metal in a pickling solution, forming nitrogen oxides and regenerating nitric acid, introducing additional oxygen into the pickling solution to further reduce the depletion of nitric acid in the pickling solution, introducing gaseous oxygen into an effluent stream, that contains etching acid vapor and nitrogen oxides, where oxygen gas is introduced in an adjustable manner, collecting and transporting the effluent stream to a first scrubbing system, in which acid gas and nitrogen oxides are removed from the effluent stream, transporting the effluent through a pipeline to a second scrubbing system, introduction of ozone into the pipeline between the first scrubbing system and the second scrubbing system, thereby mixing with the effluent stream with the oxidation of the remaining nitrogen oxides, and wet cleaning of oxidized nitrogen oxides in the effluent stream in a second scrubbing system.

EFFECT: invention provides an efficient removal of NO_x and other pollutants from the gaseous stream, reducing operating and capital costs, as well as a decrease in the outflow of fluid formed in the etching and wet cleaning operations.

56 cl, 4 dwg