| 摘要 |
<p>PURPOSE:To efficiently separate both components of V and Mo in high purity by using a caustic alkali aq. soln., mineral acid and an ammonia soln., etc., and treating an oxidized roasted material of a used catalyst contg. V and Mo in the specified plural processes. CONSTITUTION:(a) An oxidized roasted material of a used catalyst contg. V and Mo is leached by a caustic alkali aq. soln. in such conditions that free caustic alkali contained in a leaching soln. is made to <10wt%. (b) The leached soln. is subjected to solid-liquid separation at such temp. that V and Mo are not deposited. (c) Liquid phase is treated at such temp. that V is deposited and Mo is not deposited and V is separated. (d) Crude alkali molybdate is separated by concentrating and cooling a mother liquor. (e) Crude alkali molybdate is dissolved in hot water and pH is made to 10-13 and regulated to 8-9 by adding mineral acid to separate Al contents. (f) Ammonium salt contg. V is separated by decomposing liquid phase with water soluble ammonium salt. (g) Molybdic acid is separated by adding mineral acid to regulate the mixture to 3pH. (h) Molybdic acid is dissolved in an ammonia soln. and crystal of molybdic acid is deposited by adding mineral acid.</p> |
