Abstract
The “spent-acid” from the molybdenum mandrel dissolving operation in the lamp industry contains 40 to 70 g/liter of Mo and has a 15N of acidity (H2SO4 and HNO3). Four different methods of treating the {spent-acid}viz distillation, solvent extraction, ion exchange and precipitation with ammonia acid were explored. Of all the methods, precipitation by am-monia was found to be the most suitable method. In this method, ammonia is added to the “spent-acid”, and the value of the pH is adjusted between 2 and 3. The partially neutralized solution is then left stirring at 60 to 75°C for 10 to 20 h. High purity complex molybdenum oxide (4MoO3 · 2NH3 · H2O; total impurity excluding tungsten less than 100 ppm) precipitates from the solution. Molybdenum recovery is 99 pct.
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References
H. Silva: Westinghouse R & D Center, Pittsburgh, personal communication, 1972.
Powder Diffraction File 1974: Card No. 21-570, JCPDS, Swarthmore, Pa.
M.-J. Schwing-Weill: Bull. Soc. Chim. Fr., 1967, pp. 3796-98.
P. L. deBryun and G. E. Agar: inFroath Flotation, D. W. Fuerstenau, ed., p. 91, AIME New York, 1962.
D. H. Killeffer and A. Linz:Molybdenum Compounds, pp. 81, Interscience Publishers, New York, 1952.
G. P. Haight and D. R. Boston:J. Less-Common Metals, 1974, vol. 36, pp. 95–102.
C. J. Hallada:J. Less-Common Metals, 1974, vol. 36, pp. 103–10.
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Kulkarni, A.D. Recovery of molybdenum from “spent-acid”. Metall Trans B 7, 115–118 (1976). https://doi.org/10.1007/BF02652827
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DOI: https://doi.org/10.1007/BF02652827