METHOD FOR RECOVERING MOLYBDIC ACID

摘要

PROBLEM TO BE SOLVED: To provide a method for recovering molybdenum in high yield by selectively extracting molybdenum from a spent hydrogenation catalyst. SOLUTION: The method for recovering molybdic acid comprises: a step (a) of firing the spent hydrogenation catalyst containing Mo at 450-900°C; a step (b) of dispersing the fired spent hydrogenation catalyst in NH3water so that the ratio ((MN)/(MM)) of the molar number (MN) of NH3to that (MM) of MoO3is within 1.6-3 and heating the catalyst-dispersed liquid at 80-100°C to extract Mo; a step (c) of filtering and separating the catalyst-dispersed liquid into residues and an extracted Mo-containing liquid; a step (d) of adjusting the concentration of MoO3in the extracted Mo-containing liquid to 3-20 wt.% and adjusting the pH of the extracted Mo-containing liquid to 0.2-1.5 by adding an acid to precipitate molybdic acid; and a step (e) of filtering and separating the precipitated material to recover molybdic acid. COPYRIGHT: (C)2007,JPO&INPIT