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:
Dec. 04, 1979
Filed:
Dec. 14, 1977
Applicant:
Inventors:
Manfred Neidhardt, Siegburg, DE;
Gerhard Rehfeld, Aachen, DE;
Assignee:
Dynamit Nobel Aktiengesellschaft, Troisdorf, DE;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C04B / ;
U.S. Cl.
CPC ...
264140 ; 106 734 ; 264233 ; 264327 ; 264332 ; 264344 ;
Abstract
A composition comprising .alpha.-alumina in a concentration of at least 99.95 weight percent and process for producing such .alpha.-alumina wherein alumina having an alkali metal content between 0.05 and 0.60 weight percent and Al.sub.2 O.sub.3 content of more than 95 weight percent is electrically fused with silica and additional alkali, if desired, in an electric arc furnace, the heated composition is cooled, comminuted and the so-formed glass phase is removed from an alumina containing phase by mechanical or chemical means.