Rueckgewinnung von Titandioxid aus Reststoffen

In einem Verfahren zur Rueckgewinnung von Titandioxid aus Eisen und organisches Material enthaltenden Reststoffen, insbesondere Reststoffen aus der Papierherstellung, extrahiert man den Reststoff mit einer waessrigen nichtoxidierenden Mineralsaeure, gegebenenfalls bei erhoehter Temperatur, und oxidiert den nach Abtrennung der fluessigen Extraktionsmittelphase erhaltenen organischen Rueckstand pyrolytisch zu CO2 unter Erhalt eines weissen Pulvers.

DE 102005039598 A1 UPAB: 20070322 NOVELTY - The recovery of titanium dioxide from iron compounds and organic material containing residual substances, comprises extracting the residual material with 15% of hydrochloric acid as an aqueous non-oxidizing mineral acid and pyrolytic oxidation of the extracted organic residue to CO2 at 500-600degreesC, after separation of the liquid extraction agent phase. The extraction is carried out at more than 75degreesC or at the boiling temperature of the extraction agent. DETAILED DESCRIPTION - The recovery of titanium dioxide from iron compounds and organic material containing residual substances, comprises extracting the residual material with 15% of hydrochloric acid as aqueous non-oxidizing mineral acid and pyrolytic oxidation of the extracted organic residue to CO2 at 500-600degreesC, after separation of the liquid extraction agent phase. The extraction is carried out at more than 75degreesC or at the boiling temperature of the extraction agent. The mineral acid containing extraction agent is supplied to the extraction process after separating the residue and the regenerated mineral acid is again supplied to the extraction process. USE - The titanium dioxide is used as opacifier in the manufacture of white paper. The recovered titanium dioxide is useful for the manufacture of decorative papers. ADVANTAGE - Ensures pure recovery process of the titanium dioxide.