Production of molybdenum trioxide from molybdenite in a fluidized bed
AssigneeCanadian Patents and Development Limited
InventorsIgor A. Wilkomirsky, Alan Paul Watkinson, J. Keith Brimacombe
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Abstract
Molybdenite or MoS.sub.2 materials, particularly finely divided flotation concentrates, are oxidized (roasted) to form molybdenum trioxide in a continuous composite fluidized bed containing non-elutriated refractory solids. A relatively high recycle ratio of oxidized calcine to feed is maintained for best results. The temperature of the circulated oxidized solids is maintained high to avoid sticking and deposition problems. High throughputs and high conversions have been achieved, with the product having a low sulfur content.
Claims13
A continuous fluidized bed process for producing molybdenum trioxide from molybdenum disulphide materials, comprising:
- a. feeding to and fluidizing said materials in a composite fluidized bed, the feed materials having a fine particle size of the order of molybdenite ore flotation concentrates and not significantly above about 50 microns in diameter, the bed including fluidized refractory particles which are not readily elutriated from the bed, and the fluidizing gas including oxygen;
- b. oxidizing the fluidized molybdenum disulphide particles at a temperature within the range of about 450.degree. to about 650.degree.C;
- c. withdrawing oxidized particles from the bed and separating entrained oxidized particles from the off-gas stream;
- d. circulating at least part of the discrete oxidized particles to again contact a fluidized bed as in (a) and (b), the weight ratio of recycle to feed being at least about 1:1, with the temperature during both (c) and (d) being maintained sufficiently high to prevent deposition of circulating solids and vapors;
- said latter temperature being above about 250.degree.C;
- and
- e. recovering molybdenum trioxide of low sulfur content from the oxidized particles.
Dependencies are inferred from the claim text.