AQUEOUS MIXED ACID SOLUTION FOR REMOVING SMUT IN WHICH NITRIC ACID AND NITROGEN COMPONENT ARE NOT CONTAINED TO PREVENT GENERATION OF NITROGEN OXIDE(NOx) IN AIR AND GENERATION OF TOTAL NITROGEN IN WASTEWATER AND METHOD FOR REMOVING THE SMUT

摘要

PURPOSE: To provide an aqueous mixed acid solution for removing smut, the aqueous mixed acid solution capable of obtaining excellent results compared with conventional smut removal method without use of nitric acid, and a method for removing smut using the aqueous mixed acid solution for removing smut. CONSTITUTION: The aqueous mixed acid solution for removing smut of an aluminum material comprises: sulfuric acid, hydrofluoric acid, hydrogen peroxide and H2O, wherein a composition for the solution comprises 5 to 60 wt.% of sulfuric acid, 0.13 to 3 wt.% of hydrofluoric acid, 0.5 to 20 wt.% of hydrogen peroxide and the balance being H2O, wherein a composition for the solution comprises 10 to 20 wt.% of sulfuric acid, 0.5 to 1 wt.% of hydrofluoric acid, 1 to 3 wt.% of hydrogen peroxide and the balance being H2O, wherein the solution further comprises 0.01 to 5 wt.% of a hydrogen peroxide stabilizer containing 4-hydroxy-benzoic acid, phenyl urea or a mixture thereof, wherein the hydrogen peroxide stabilizer further contains high stabilization hydrogen peroxide, wherein the solution further comprises 0.50 to 1.50 wt.% of at least one or more surfactants selected from the group consisting of cationic surfactant, nonionic surfactant and anionic surfactant, and wherein the solution further comprises at least one or more compounds selected from the group consisting of organic alcohol series or metal peroxides of chromium and molybdenum.