Location Eureka County Country United States Financial year 2008 Production Silver Opened 1986 | State Nevada Products Gold , Silver Address Nevada, USA Company Barrick Gold | |
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Website Goldstrike Complex webpage | ||
Shot at barrick goldstrike mine on the carlin trend
Goldstrike is a gold mine in Eureka County in north-eastern Nevada. It is located on the Carlin Trend, a prolific gold mining district. It is owned and operated by the world's largest gold mining company, Barrick Gold. Goldstrike is the largest gold mine in North America.
Contents
Open pit gold mining
HistoryEdit
Gold was first mined from the upper, well-oxidized portion of what became the Post deposit in 1976 by PanCana Minerals Ltd., in a small open-pit heap leach operation. In 1978, Western State Minerals Corporation entered into a joint venture (JV) with PanCana. The JV delineated ore reserves for the Post deposit in 1986, and mining started in 1987. Barrick acquired 100% ownership of the property that year.
GeologyEdit
The Goldstrike mine complex (including the Betze-Post-Screamer and Meikle-Rodeo deposits) is the largest Carlin-type mine in the world. The Goldstrike mine adjoins Newmont Mining's Carlin mine complex. Goldstrike is northwest of the Carlin mine on the Carlin Trend.
Like most Carlin type gold deposits in Nevada the gold was epithermally deposited in carbonate or silicate sedimentary rocks. The source of the heat was magmatic but the exact mechanism is still under debate. The Betze-Post deposits are up to 6,000 feet (1,800 m) long, 600 feet (180 m) thick and 800 feet (240 m) wide. In 2007 the average processed gold grade was 0.136 troy ounces (4.2 g) per ton of ore, with a recovery rate of 85.5%.
Mining operationsEdit
The Goldstrike complex consist of three distinct mines: the large Betze-Post open-pit mine, and the Meikle and Rodeo underground mines. The ore from all three mines was milled and leached by the cyanide process. Starting in 2015 ore began to be extracted using calcium thiosulfate, instead.
Carlin-type gold deposits host gold mainly as microscopically fine grains. Refractory non-carbonaceous sulphide ore is treated in an autoclave followed by a carbon-in-leach (CIL) cyanidation circuit. Carbonaceous ore, also refractory, is treated with a roaster followed by a CIL circuit. The two treatment facilities treat ores from both the open pit and underground mines. Recovered gold is processed into doré on-site and shipped to outside refineries for processing into gold bullion.
In 2008 the Betze-Post open-pit mine produced 1,281,450 oz (36,328 kg) of gold and 152,886 oz (4,334.2 kg) of silver, while the Meikle-Rodeo underground operations yielded 424,687 oz (12,039.7 kg) of gold and 51,438 oz (1,458.2 kg) of silver. This was 30% of the total 5,698,000 oz (161,500 kg) output of all gold mining operations in Nevada.