Patent ID: 6250314
Filing Date: 2001-06-26
Classification: C23G

Abstract:
A process for pickling stainless steel comprising the steps offeeding a stainless steel article into a pickling tank containing aqueous hydrochloric acid solution, and pickling said stainless steel article to form Fe.sup.2+ as ferrous chloride (FeCl.sub.2) and Fe.sup.3+ as ferric chloride(FeCl.sub.3) in said hydrochloric acid solution, andcontinuously adding an oxidant to said hydrochloric acid solution in an amount in proportion to a surface area of the stainless steel article to oxidize said Fe.sup.2+ to Fe.sup.3+ to maintain at least about one third of a total dissolved iron content as ferric chloride in said hydrochloric acid solution, said oxidant being selected from the group consisting of nitric acid, chlorine, hydrogen peroxide, chlorine-oxygen compounds, and ferric chloride.