Appeal No. 1997-0448
Application No. 08/327,980
1. A process for producing molybdenum trioxide of at least technical grade
from molybdenite concentrate containing molybdenite, at least one of copper in excess
of 5 wt % or naturally floatable gangue minerals in excess of 10 wt %, each based on
the weight of the concentrate, the process comprising the steps of:
A. contacting an aqueous suspension of the concentrate with oxygen under
a partial pressure of free oxygen of between about 75 and 200 psi and
at a temperature of at least about 150 C such that at least about 95%
of the molybdenite is oxidized to form a soluble hydrous molybdic
oxide and insoluble molybdenum trioxide;
B. separating the soluble molybdic oxide from the insoluble molybdenum
trioxide;
C. contacting the insoluble molybdenum trioxide with a solubilization
compound to form an aqueous mixture of soluble molybdate values and
insoluble residue;
D. separating the soluble molybdate values from the insoluble residue;
E. combining the soluble molybdate values of step D with the soluble
molybdic oxide of step A to form an aqueous mixture containing soluble
molybdenum values;
F. contacting the aqueous mixture of step E with an organic solvent
containing an extractive compound that is selective for the molybdenum
values such that a majority of the metal contaminants remain in the
aqueous mixture while a majority of the molybdenum values are
extracted into the organic solvent;
G. removing the extracted molybdenum values of step F from the organic
solvent by contacting the organic solvent with an aqueous solution
containing a stripping reagent selective for molybdenum values;
H. crystallizing the extracted molybdenum values of step G; and
I. calcining the crystallized molybdenum values of step H to produce
molybdenum trioxide.
2. The process of Claim 1 in which the solubilization compound of step C is an
alkali metal compound.
18. A process for producing molybdenum trioxide of at least technical grade
from molybdenite concentrate containing molybdenite, at least one of copper in excess
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