Process for the treatment of catalysts from silicate-phosphate materials to obtain phosphoric acid

摘要

The invention relates to a process for the treatment of used catalyst material containing silicate-phosphate materials based on silicon, oxygen, hydrogen and phosphorus to yield phosphoric acid, comprising the steps: a) calcining the catalyst material at 250 to 950 B) i) treating the calcined material with water and / or a mineral acid or mineral acid mixture to form silicate residue and crude phosphoric acid; or iii) treating the calcined material with an inorganic base to form silicate residue and a basic solution or suspension containing dissolved and / or undissolved phosphorus salts of the base, c) acid digestion of the undissolved phosphate salt and / or purification of the crude phosphoric acid to obtain phosphoric acid.