Method of recovering rhenium by fluidized-roasting rhenium-containing minerals

Abstract

The invention relates to the technical field of rhenium recycling and particularly relates to a method of recovering rhenium by fluidized-roasting rhenium-containing minerals. The method provided by the invention comprises the following steps: feeding the rhenium-containing minerals into a boiling furnace by virtue of an automatic feeding device for fluidized-roasting; separating a rhenium-containing gas obtained by roasting from roasting dust by virtue of a dust collecting system to recover rhenium; and before roasting the rhenium-containing minerals, firstly, preparing bulky porous pellets uniform in particle size by a granulator, wherein the particle size of the pellets is over 0.5mm. The method provided by the invention overcomes the defects that the rhenium recovery rate is affected and much roasting dust exists due to low oxidizing roasting efficiency of the rhenium-containing minerals in the prior art. By changing the shapes of the rhenium-containing minerals, the sublimation rate of rhenium and the rhenium recovery rate are increased. The sublimation rate of rhenium reaches over 99.9% and the rhenium recovery rate reaches over 95%. The amount of the roasting dust is reduced and can be reduced to below 10% of the feed quantity, the unit production capacity is improved, and the enterprise cost is lowered.

Description

technical field [0001] The invention relates to the technical field of rhenium recovery and utilization, in particular to a method for recovering rhenium by fluidized roasting rhenium-containing minerals. Background technique [0002] Rhenium is a sparse and refractory metal with a melting point of 3180°C, second only to tungsten; rhenium is very hard, corrosion-resistant, wear-resistant and has good ductility, especially because of its densely packed hexagonal crystal structure, it can be maintained at low temperatures Hardness and ductility, and maintain high strength and good creep resistance under high temperature and sudden temperature changes. Rhenium-containing alloys can still maintain their strength, ductility and hardness at high temperatures, so rhenium is widely used and can be used as Platinum-rhenium catalysts for platinum reforming units for producing high-octane gasoline (using its special anti-nitrogen, sulfur, and phosphorus poisoning performance, accountin...

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Problems solved by technology

[0017] In the above method of circularly roasting molybdenum concentrate, the rhenium-containing molybdenum concentrate is continuously input into the fluidized furnace with particles of 20-200 mesh (425-850 μm) in size. , the specific surface area is small, and it is not easy to be fluidized by blasting. The particle size must be strictly controlled to meet the requirements of fluidization, and it is not easy to burn through during the roasting process. Fully oxidized, only about 70-85% of the ore particles are oxidized, and it also contains 8-10% residual sulfur, which must be returned to the fluidized furnace for re-roasting. The sublimation rate of rhenium is only 90%, which affects the recovery rate of rhenium (A.H. Zelek Mann, O.E. Klein et al., "Rare Metal Metallurgy", September 1982, p. 108);

[0018] Moreover, in CN102653821A, since the molybdenum concentrate raw material is composed of particles of different sizes from 20 to 200 meshes, when the fluidized bed of the fluidized bed is formed, the molybdenum concentrate raw material is continuously added, and the air supply system is continuously blown to form an upward In the flowing air flow, the added molybdenum concentrate particles are in a violently moving boiling state. Since the molybdenum concentrate particles are thick and thin, under the same blowing conditions, the molybdenum concentrate particles at the fine-grained end of the particle group will inevitably float up automatically. It is taken away by the furnace gas without being fully oxidized or even oxidized and enters the dust collection system. At least 1 / 3 of the fine-grained raw material particles enter the dust collection system due to excessive blasting and insufficient oxidation. Practice has found that in ensuring the fluidized bed Under normal fluidization, the amount of molybdenum concentrate dust brought into the dust collection system with the furnace gas far exceeds the existing reports by 20-40% ((A.H. Zelekman, O.E. Klein et al., "Rare Metallurgy", September 1982; Edited by Lin Chunyuan and Cheng Xiujian, "Molybdenum Mineral Processing and Deep Processing", March 1997), almost 40-50% of molybdenum concentrate particles enter the dust collection system, and these enter the dust collection system The dust in the dust contains more unoxidized mineral materials, which seriously affects the oxidation recovery of rhenium in the rhenium-containing minerals, and the sulfur content in the dust is more than 10%, so it must be returned to the fluidized roasting furnace for re-roasting; In practice, because the particle size of the mineral raw material itself is too fine and the particle size range is too large, the roasting cycle is too large, so that the entire roasting system cannot continue continuously, so the furnace has to be stopped.

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