Process for the preparation of catalysts from silicate phosphate materials from the extraction of phosphoric acid

摘要

Processes for the preparation of used catalyst material containing silicate phosphate materials based on silicon, oxygen and phosphorus, as well as varying proportions of hydrogen, including the extraction of phosphoric acid, covering the steps:(a) calcination of the catalyst material at 250 to 950oC in an oxygen-containing atmosphere;(b) i) treatment of the calcined material with water and/or a mineral acid or mineral acid mixture, resulting in silicic residue and crude phosphoric acid;or(ii) treatment of the calcined material with an inorganic base, forming a silicate residue and a basic solution or suspension, containing the base's dissolved and/or insoluble phosphorus salts;(c) Acute detection of the insoluble phosphate salt or purification of the crude phosphoric acid for the extraction of phosphoric acid.