The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 06, 1987
Filed:
Feb. 05, 1986
Edward L Cambridge, Tucson, AZ (US);
Raouf O Loutfy, Tucson, AZ (US);
James C Withers, Tucson, AZ (US);
Daniel M Blake, Tucson, AZ (US);
Atlantic Richfield Company, Los Angeles, CA (US);
Abstract
A process is described for the formation of high purity alumina from Bayer Process alumina trihydrate (gibbsite). The solid hydrated alumina is reacted with concentrated HCl to cause partial or complete conversion to aluminum chloride hexahydrate (ACH). The ACH or mixture of ACH and unreacted hydrated alumina is recovered as a solid and calcined in a single or multistage calcination to high purity alumina. Soda contents in the product anhydrous alumina can be reduced by 98% or greater. Contents of other impurities, such as silica, iron, magnesium, etc., are also markedly reduced. Different degrees of impurity reduction can be obtained by controlling the degree of conversion of the hydrated alumina to ACH and by recycling and treating the acid after solid/liquid separation. The purified products find use in the specialty ceramics field, as catalyst supports, as adsorbents, in electronic components, in prosthetic devices or other applications in which alumina of controlled degrees of purity offers an advantage.