REGENERATION METHOD OF WASTE NOx GAS GENERATED WHEN PICKLING STAINLESS STEEL WITH MIXED ACID OF SULFURIC ACID AND HYDROGEN PEROXIDE

摘要

PURPOSE: A regeneration method of waste NOx gas generated when pickling stainless steel with mixed acid of sulfuric acid and hydrogen peroxide is provided, in which NOx gas is primarily removed by sulfuric acid in advance, and then hydrogen peroxide is used to remove residual NOx gas. CONSTITUTION: The method includes the steps of (i) adding 1% or less sulfuric acid in pickling bath to remove NOx gas emission from stainless steel pickling process; and (ii) according to NOx gas concentration detected after above step, continuously adding hydrogen peroxide to above pickling solution for the purpose of reacting residual NOx gas with hydrogen peroxide to generate nitric acid.