VERFAHREN ZUR HERSTELLUNG VON MISCHOXIDPULVERN AUS DESAKTIVIERTEN KATALYSATOREN ZUR STICKOXIDMINDERUNG IN ABGAS

摘要

Producing mixed oxide powders from deactivated de-NOx catalysts comprises: (a) crushing the deactivated catalysts; (b) treating the crushed material to remove thallium with an aqueous mineral acid; (c) decomposing the material liberated from thallium with H2SO4 and/or oleum; (d) absorbing the decomposed cake in water or diluted H2SO4 and removing the undissolved components; (e) liberating the solution obtained from arsenic (f) hydrolysing the solution liberated from arsenic, filtering and optionally working up the diluted H2SO4 forming and (g) drying the hydrolysate obtained after past-doping with compounds of W, Mo and/or V, and calcining to give the final product.