PROCESS FOR THE EXTRACTION OF THE MOLYBDENUM COMPOUND FROM THE MOTHER WATERS AND/OR THE WASHING WATERS OF THE PRECIPETATE AND/OR EXHAUSTED CATALYST IN A PROCESS FOR THE PREPARATION OF A CATALYST BASED ON MOLYBDENUM

摘要

Preparation of a catalyst based on molybdenum and iron oxides by precipitation from a soluble molybdenum compound and a soluble ferric salt, with separation of the precipitate from its mother waters and washing with deionized water. Molybdic ions are recovered from the mother waters and washing waters by contacting the latter with a salified anionic exchange resin, which is then contacted with aqueous alkali metal hydroxide to yield an aqueous solution of alkali metal molybdate. The molybdenum thus recovered may be recycled to the precipitation step upon conversion of the molybdate into molybdic acid by treatment with a strong cationic exchange resin, and possible conversion of the acid into ammonium paramolybdate.