Abstract: The subject matter of the present invention is a method to extract or recover hydrochloric acid from hydrochloric acid solutions containing metal by means of pyrohydrolytic treatment, followed by absorption and/or condensation of the gaseous hydrogen chloride thus formed in order to form hydrochloric acid. According to the invention, a first partial flow of the hydrochloric acid solution containing metal undergoes pyrohydrolytic treatment and a second partial flow of the metal-containing solution is fed to the absorption column. A device for implementing the process according to the invention is also the subject of the present invention.

Abstract: The subject matter of the present invention is a method to extract or recover hydrochloric acid from hydrochloric acid solutions containing metal by means of pyrohydrolytic treatment, followed by absorption and/or condensation of the gaseous hydrogen chloride thus formed in order to form hydrochloric acid. According to the invention, a first partial flow of the hydrochloric acid solution containing metal undergoes pyrohydrolytic treatment and a second partial flow of the metal-containing solution is fed to the absorption column. A device for implementing the process according to the invention is also the subject of the present invention.

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.

Abstract: A method of producing a cold-rolled strip from a stainless, ferretic or austenitic high-grade steel or a titanium alloy, wherein the strip which has been wound into a coil and has been manufactured by a hot-rolling or casting process is subjected in one pass to the steps of unwinding the coil, mechanically descaling the strip if required, subsequently chemically and/or electrochemically first or black pickling of the strip, then cold-rolling the strip to finished dimensions, degreasing the strip as required, annealing the strip, finish-pickling the strip and, if necessary, passivating, dressing and stretcher-leveling the strip. The pickling step is carried out in a pickling solution which contains hydrochloric acid, sulfuric acid and/or nitric acid.