04979987 is referenced by 14 patents and cites 134 patents.

Precious metal values, particularly gold and silver, are liberated from refractory, carbonate ores by adjusting the molar ratio of sulfide to total acid consumers to between about 1.2 and about 3.2 in the ore feed to a pressure oxidation process. The ore is contacted with oxygen to oxidize sulfide in the ore with at least about 65 percent of the sulfide oxidation occurring in a first oxidation zone at a temperature above about 360.degree. F. The oxidation of sulfide forms at least about 5 grams of free sulfuric acid in the first oxidation zone. The oxidation process is continued in subsequent oxidation zones. A gas stream is removed from the oxidation zones and oxygen is separated from carbon dioxide and other inerts in the gas stream and the purified oxygen is recycled to the oxidation zones.

Title
Precious metals recovery from refractory carbonate ores
Application Number
7/221085
Publication Number
4979987
Application Date
July 19, 1988
Publication Date
December 25, 1990
Inventor
Robert Pendreigh
West Vancouver
CA
Patrick T O Kane
Coquitlam
CA
Peter C Mason
North Vancouver
CA
Agent
Sheridan Ross & McIntosh
Assignee
First Miss Gold
NV, US
IPC
C22B 11/00
C01G 7/00
C01G 5/00
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