The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 23, 2002
Filed:
Nov. 12, 1997
Frank Bärhold, Quirnbach, DE;
Werner Engelhardt, Bendorf, DE;
Keramchemie GmbH, Siershahn, DE;
Abstract
In a method of regenerating a spent pickling solution composed of nitric acid and hydrofluoric acid and containing metal fluorides and metal nitrates, the pickling solution is heated in a reactor to about 300-1,000° C., the metal fluorides and the metal nitrates are pyrohydrolized, and the metal oxides formed as a result are removed as a granulate, and the gas produced in the fluodized bed reactor is dedusted, cooled and fed to an acid recovery unit. The spent pickling solution is initially separated in a separating process into a partial flow with free acid and into a partial flow enriched with metal salts, and the partial flow enriched with free acid is fed to the acid recovery unit and the partial flow enriched with metal salts is fed to the fluidized bed reactor.