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:
Jul. 30, 1985
Filed:
Jun. 21, 1984
Roland Bachelard, Lyons, FR;
Maurice Lamalle, Saint-Genis-Laval, FR;
Produits Chimiques Ugine Kuhlmann, Courbevoie, FR;
Abstract
Processes for the preparation of pure alumina powders or pure non-stoichiometric alumina-magnesia spinel powders starting with ammonium alum-based compositions which are dehydrated, the dehydration being carried out on dehydrated salts having a bulk density less than 0.2 kg/dm.sup.3 and wherein the dehydration is followed by a calcination with a heating schedule containing at least one intermediate stage at 750.degree. to 850.degree. C., the process of the invention permitting the reproducible production of such aluminas or spinels having specific surfaces of from 100 to 200 m.sup.2 /g and characterized by a very high homogeneity which guarantees a rigorously unimodal pore structure, such aluminas and spinels being useful in preparing isotopic enrichment barriers for gaseous diffusion, as well as metal polishes, catalysts, and catalyst supports.