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.

Date of Patent:
Dec. 10, 1991

Filed:

May. 03, 1990
Applicant:
Inventors:

Kenneth G Thomas, Mississauga, CA;

Herman J Pieterse, Elko, NV (US);

Robert E Brewer, Elko, NV (US);

Kevin S Fraser, Milton, CA;

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C22B / ;
U.S. Cl.
CPC ...
75744 ; 423 29 ;
Abstract

The present invention is directed to an improvement in a process for the recovery of gold from refractory sulfidic auriferous ores which comprises oxidizing a slurry of ore with oxygen gas under pressure in the presence of sulfuric acid, neutralizing the oxidized slurry, cyanidizing the neutralized slurry to leach gold therefrom, and recovering gold from the resultant leachate. In accordance with the improved process, the oxidation of the ore slurry is carried out in a manner whereby, after a startup phase during which oxidation is initiated, the amount of sulfuric acid added to the ore slurry is sufficient to insure the oxidation of that portion of the sulfide sulfur in the ore which will allow recovery, by cyanide leaching, of at least about 80% of the gold in the ore. The oxidized slurry can be neutralized without a washing operation.


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