Process for treating and recovering pickling waste liquids for stainless steel
CA 1237644 A · Owner: Kawasaki Steel Corporation · Inventors: Hoshino, Minoru; Watanabe, Toshio; Nakazato, Yoshio
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process for treating and recovering pickling waste liquids used for the pickling of stainless steel such as nitric-hydrofluoric acid, nitric acid hydro-, chloric acid and, sulfuric acid is disclosed which, comprises recovering the nitric-hydrofluoric acid and the iron oxide or metallic ion from the waste liquids of nitric-hydrofluoric acid and nitric acid by two solvent extraction processes and recovering the Cr and Ni containing ferrite from the waste liquids of sulfuric acid or hydrochloric acid by a ferrite formation process. When the waste acid is sulfuric acid gypsum of a high, purity can be obtained.
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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Granted June 7, 1988. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended June 7, 2005.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.