Process for Conversion of Aluminum Oxide Hydroxide
AssigneeUop LLC
InventorVladislav I. Kanazirev
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Abstract
The present invention is a process for the conversion of aluminum oxide hydroxide (AlOOH) to aluminum oxide. About 30 to 70 wt-% of AlOOH, about 30 to 70 wt-% ammonium hydrogencarbonate NH4HCO3 and 0 to 20 wt-% water are combined to produce a mixture. This mixture is then cured at a temperature from about 30° to about 90° C. to convert at least 5% of the AlOOH to a ammonium hydroxycarbonate (dawsonite-type) intermediate and then the dawsonite-type intermediate is decomposed at a temperature from about 130° to 320° C. to produce aluminum oxide. The aluminum oxide can be further calcined at 500° to 800° C. to produce a gamma-theta phase alumina.
Claims21
A process for the conversion of aluminum oxide hydroxide (AlOOH) to aluminum oxide comprising:
- a) mixing about 30 to 70 wt-% of AlOOH, about 30 to 70 wt-% ammonium carbonate compound and 0 to 20 wt-% water to produce a mixture;
- b) curing the mixture at a temperature from about 30° to about 90° C. to convert at least 5% of said AlOOH to an ammonium hydroxycarbonate (dawsonite-type) intermediate;
- and
- c) then decomposing said ammonium hydroxycarbonate intermediate to aluminum oxide at a temperature from about 130° to 320° C.
An aluminum containing composite consisting of an aluminum oxide hydroxide base comprising agglomerated particles having rod-like species consisting of ammonium aluminum hydroxycarbonate embedded in said aluminum oxide hydroxide base.
Dependencies are inferred from the claim text.