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:
Oct. 12, 1976
Filed:
May. 29, 1975
Applicant:
Inventors:
Christopher William Bradford, London, EN;
Stephen George Baldwin, London, EN;
Assignee:
Johnson Matthey & Co., Limited, London, EN;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C01G / ;
U.S. Cl.
CPC ...
423 22 ; 75102 ; 75114 ; 75121 ; 252415 ;
Abstract
In order to recover platinum, rhodium and other precious metals from catalysts employed in internal combustion engine exhaust systems, the used or unused catalysts, preferably in crushed, powdered or broken form, are reacted with an acidic medium having oxidizing properties to leach out the precious metals. The acidic medium may be an acid containing or oxidizing agent or an oxidizing acid and when a used catalyst is treated the leaching step is preferably preceded by a reduction step in order to convert to the metal any precious metal oxides present in the catalyst.