Method of thermally splitting hydrate of aluminum chloride
AssigneeAluminum Pechiney
InventorsLothar Reh, Ludolf Plass, Philippe Marchessaux, Raman Sood
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Abstract
Thermally splitting hydrate of aluminum chloride to produce aluminum oxide wherein the hydrate is at least partially split by contact with hot gases and hot calcined product in a turbulent zone, transmitting the material from the turbulent zone into a residence zone, recycling a portion of the solids from the residence zone to the turbulent zone in an amount to maintain a desired suspension density while the remainder is passed to a turbulent cooling zone in heat exchange with the fluidizing gas introduced into the turbulent zone.
Claims15
A method of thermally splitting hydrate of aluminum chloride to form aluminum oxide using a splitting zone, a separate turbulent zone, and a separate residence zone and a cooling zone comprising:
- (1) feeding the hydrate of aluminum chloride into the splitting zone;
- (2) fluidizing the hydrate of aluminum chloride while in the splitting zone by the introduction of a fluidizing gas;
- (3) heating the fluidized hydrate of aluminum chloride in the splitting zone partially to split the hydrate of aluminum chloride while in the splitting zone;
- (4) cycling partially split aluminum chloride from the splitting zone to the turbulent zone;
- (5) fluidizing the solids in the turbulent zone by introduction of gas from the cooling zone to the lower portion of the turbulent zone;
- (6) heating the fluidized solids in the turbulent zone to advance the splitting reaction;
- (7) cycling the heated solids from the turbulent zone to the residence zone for further completion of the splitting of the hydrate of aluminum chloride to aluminum oxide;
- (8) recycling a portion of the solids from the residence zone to the turbulent zone for admixture with the partially split aluminum chloride from the splitting zone;
- (9) passing the remainder of the solids from the residence zone to the cooling zone for passage in heat exchange relation with fluidizing gas to yield a preheated gas fed to the turbulent zone and a cooled aluminum oxide as product;
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- (10) recycling a portion of the solids from the turbulent zone to the splitting zone for supply of heat to the splitting zone and for admixture with the hydrate of aluminum chloride introduced into the splitting zone.
The method as claimed in 11, in which within the turbulent zone an average suspension density of 20 to 300 kg/m.sup.3 is established in the region between the introduction of fluidizing gas and the secondary gas, and an average suspension density is 1 to 20 kg/m.sup.3 in the region above the introduction of secondary gas.
Dependencies are inferred from the claim text.