METHOD OF THERMALLY TREATING POWDERED ALUMINUM HYDROXIDE Russian patent published in 2006 - IPC C01F7/44 

FIELD: inorganic compounds technologies.

SUBSTANCE: invention relates to technology of processing powdered materials, especially aluminum hydroxide, and can be used in manufacture of building materials and treatment metallurgical raw materials for production of aluminum. Method involves preliminary concurrent drying of wet aluminum hydroxide in emission gas flow, cyclone separation of dried aluminum hydroxide, preliminary concurrent heating thereof in emission gas flow from top portion of reaction chamber and supply thereof into lower portion of reaction chamber, firing of powdered aluminum hydroxide in fluidized state in ascending flow of heat carrier prepared by burning fuel in oxygen-containing gas phase, cyclone precipitation of alumina obtained, multistep concurrent cooling thereof with air flow supplied to reaction chamber to produce alumina product. In this case, firing of aluminum hydroxide is effected consecutively in flow of heat carrier prepared by burning a part of fuel consumed for firing of fuel in heated air being cooled with alumina and in flow of heat carrier prepared by burning the rest of fuel directly in ascending gas-powder- mixture.

EFFECT: improved quality of alumina product, reduced expenses on heat treatment on the whole by means of reducing local overheating of alumina hydroxide particles and surface layer of refractory lining in the initial stage of firing, and increased fullness of firing of material in the final stage.

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