Appeal No. 1997-0448
Application No. 08/327,980
filtering the resultant acid aqueous slurry to separate the insoluble molybdenum trioxide product, which
also contains unreacted molybdenum disulfide and any other solid contaminating material, e.g., silica,
from the filtrate which contains some dissolved molybdenum sulfate; (C) transferring the filtrate to a5
neutralizer wherein a caustic is added to precipitate dissolved molybdenum trioxide which is recovered
by filtration; (D)(1) contacting the insoluble molybdenum trioxide product with aqueous ammonium6
hydroxide, thereby producing soluble ammonium molybdate; (D)(2) filtering the ammonium molybdate
7 8
from residual solid contaminants; (D)(3) concentrating the ammonium molybdate in a crystallizer; and
(D)(4) calcining to produce ammonium gas which is recycled back to aqueous ammonium hydroxide,
thereby yielding high purity molybdenum trioxide. The9
residual solid contaminants of (D)(2) is preferably accumulated and treated as in steps (A) through
(D)(2) above, with the corresponding filtrate containing ammonium molybdate being combined with the
filtrate of step (D)(2) above.10
5See Barry, col. 4, lines 61-75.
6See Barry, col. 5, lines 1-8.
7See Barry, col. 5, lines 22-40.
8See Barry, col. 5, lines 41-43.
9See Barry, col. 5, lines 43-50.
10See Barry, col. 5, line 51 - col. 6, line 3.
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