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. 02, 1991
Filed:
Feb. 14, 1990
Applicant:
Inventors:
Assignee:
Material-Concepts-Research Limited, Don Mills, CA;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C01G / ;
U.S. Cl.
CPC ...
423622 ; 423105 ; 210197 ;
Abstract
A process is provided for obtaining high quality high surface area zinc oxide from a roasted zinc sulphide concentrate by leaching with an ammoniacal ammonium carbonate solution. The process utilizes optional preliminary oxidation and water leaching steps to remove soluble impurities and an optional aqueous sulphur dioxide leaching step to selectively remove readily soluble zinc oxide. The process also includes an optional reduced pressure calcining step to produce zinc oxide with further increased surface area.