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:
Nov. 28, 2000
Filed:
Aug. 02, 1999
Applicant:
Inventors:
Michel M Lawrence, Inver Grove Heights, MN (US);
Michael A Kepros, South St. Paul, MN (US);
Assignee:
GNB Technologies, Inc., Mendota Heights, MN (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C22B / ; C01G / ;
U.S. Cl.
CPC ...
423 89 ; 423619 ; 241 241 ;
Abstract
A process for providing a leady oxide having reduced levels of undesired metallic impurities such as, for example, bismuth and/or silver, comprises roasting the leady oxide to convert part to orthorhombic PbO, exposing the roasted leady oxide to particle size reduction so that the tetragonal PbO can be separated from the orthorhombic PbO fraction, and recovering the orthorhombic fraction having the reduced level of impurities.