The USA is the world’s second largest gold producer, after South Africa. The country produced 285 t in 2003, representing a dramatic drop from 2000’s total of 355 t. Gold was produced at about 53 major lode mines, a dozen or more large placer mines (nearly all in Alaska), and numerous smaller placer mines (mostly in Alaska and in the Western States). In addition, a small amount of domestic gold was recovered as a byproduct of processing base metals, chiefly copper. Thirty mines yielded more than 99% of the gold produced in the United States.
Domestic output continued to be dominated by Nevada, where combined production accounted for more than 80% of the U.S. total. Between July 2002 and August 2003, two gold mines were closed in the United States. During this 12-month period, the average output per mine decreased, companies merged, and the size of gold-mining operations increased. Most of the larger companies were successfully replacing annual production with new reserves, but smaller companies were finding this more difficult.
The Carlin Trend in Nevada has been responsible for most of the USA’s gold production and is responsible for forming a stable mining platform for several global major gold producers such as Newmont, Placer Dome and Barrick. Gold mineralisation in the Carlin Trend is characterised by a large low grade sedimentary carbonate hosted gold resource.
The USA is the lowest cost gold producer (cash costs of $185/oz) in the world, followed by Canada, Australia and South Africa. The most significant gold development in the USA is the Cortez joint venture in Nevada, which contributed 35t. However, the poor gold price and rising costs have placed several of Nevada’s flagship mines under pressure, resulting in job losses and mine suspensions.
Newmont Mining remains the USA’s largest gold producer, with 3 Moz being produced from its Nevada Operations near Elko, Nevada in 2000. Newmont was responsible for the discovery of the Carlin Trend in 1961, and has since developed 17 open pit and four underground mines in Nevada, employing a total of 3000 people. It also has a 50% interest (Hecla Mining has the remaining interest) in the underground Rosebud mine situated in Pershing County, Nevada. Production from the Nevada mines has exceeded 1.5 Moz per year for the past seven years. Due to the varied oxide and carbon/sulphide refractory ores that are found intermixed throughout the mine, Newmont has had to employ several methods of gold extraction.
Placer Dome is the second largest gold producer in the USA with most operations in Nevada as well as a single mine in Montana. Placer Dome is one of the world’s lowest cost gold producers, with cash costs at the Cortez – Pipeline Joint Venture with Kennecott Minerals (wholly owned subsidiary of Rio Tinto) totaling $58/oz. The Cortez – Pipeline joint venture in Nevada is Placer Dome’s flagship mine, along with the Granny Smith mine in Australia. Placer Dome has a 60% interest in both operations. The Cortez – Pipeline joint venture includes the development of three distinctive ore bodies, of which the Cortez Mine is one. Production at the Cortez Mine has ceased, but the remaining two Carlin type deposits at Pipeline and South Pipeline are being developed and have proven and probable reserves estimated at containing 7.7 Moz gold. At present, the Pipeline deposit produces 74% of Cortez’ production with the remaining 26% sourced from the South Pipeline deposit. The joint venture produced 1Moz in 2000. An additional gold resource has been located close to the Pipeline Pit – called the Crossroads deposit it has a resource of some 500 000 oz gold.
Also in Nevada, Placer Dome operates the smaller Bald Mountain Mine situated in White Pine County. The heap leach operation produced 135 000 oz gold in 2000. Production at Bald Mountain is set to increase with the commissioning of the Mooney Basin heap leach operations. The open cast Golden Sunlight Mine is situated in southwestern Montana. The mine’s production is set to decline as reserves are mined out. Placer Dome’s latest acquisition is the Getchell Prospect in northwestern Nevada. Getchell comprises two underground operations, the Getchell mine and the Turquoise Ridge deposits, both containing proven and probable reserves totaling over 9.5 Moz.
Apart from its involvement in the Cortez – Pipeline venture, Rio Tinto (through its subsidiary Kennecott Minerals Company) also produces gold from four other operations in the USA. Gold is produced as a by product of the Bingham Canyon copper gold mine in Utah. Bingham has proven and probable gold reserves estimated at 877 Mt grading at 0.37 g/t gold. The 100% owned opencast Ridgeway Mine is located in South Carolina. The mine has reached the end of its exploitable ore reserves and is due to close. At the end of 1998, Ridgeway had remaining proven and probable reserves of 4.3 Mt grading at 1.1 g/t gold. The Denton Rawhide Mine (Rio Tinto 51%) in Nevada is a joint venture with Dayton Mining Corporation. Rawhide was discovered in the early 1900’s and produces gold and silver in dore bars. Rio Tinto’s Flambeau Mine in Wisconsin closed in 1997.
The newly merged entity Barrick / Homestake owns and operates several operations in Nevada, California and South Dakota. The Goldstrike property, which includes the Meikle and Betze – Poste Mines is situated along the Carlin Trend in Nevada. The Goldstrike property produces nearly 60% of Barrick’s gold every year that totalled 3.7 Moz in 2000). The Betze – Poste Mine is an open cast operation that produced over 1.6 Moz in 2000, making it the world’s fourth largest gold mine (production). Under an agreement with Newmont, the mine also extracts ore from contiguous ore bodies in the area. The underground Meikle Mine is regarded as one of Barrick’s flagship mines, producing 805 000 oz gold in 2000. In addition to Meikle, Barrick are evaluating the Screamer, Rodeo and Griffin ore bodies that are considered extensions to the Meikle orebody. The Rodeo deposit is located in between the Meikle and Betze – Post operations and has reserves estimated at containing 2.7 Moz gold. At full production (anticipated to begin in mid 2001), Rodeo will contribute 350 000 oz to Meikle’s production. The new merger will also add Homestake’s three mines in Nevada, one in California and one in South Dakota. The Ruby Hill Mine near Eureka, Nevada is one of Barrick Homestake’s lowest cost gold producers. The company’s namesake mine, The Homestake Mine in South Dakota has been in operation for over 120 years and has produced over 40 Moz gold to date. The Round Mountain Mine in Nevada is a joint venture between Barrick (50%) and Echo Bay Mines (50%). It is the largest open pit heap leach operation in North America.
Barrick has a 33% interest in the Marigold mine located near Winnemucca in Nevada. Glamis Gold owns the remainder and is operator of the mine that is expected to produce 180 000 oz per year, based on ongoing work on Glamis’ Millenium Project, an expansion to Marigold. Millenium should extend the life of the Marigold mine by some 8 years.
Echo Bay Mines also operate the McCoy/Cove gold mine in Nevada that is winding down operations. Underground mining has ceased.
Battle Mountain Gold (part of Newmont) owns the Battle Mountain Complex in central Nevada. The complex includes the Phoenix project, which contains an estimated 6.1 Moz gold grading at a grade of 1.34 g/t, using a gold price of $300/oz.
In Alaska, Kinross Gold operates the Fort Knox mine.In Alaska NovaGold Resources, Placer Dome and Calista Corporation are making good progress on the development of the Donlin Creek Gold Deposit that has a potential gold resource of over 13 Moz gold, making it one of North America’s largest unexploited gold deposits. Donlin Creek is located more than 500km west of Anchorage in southwest Alaska. Initial studies suggest an annual production of at least 600 000 oz.
In California, Canyon Resources operates the open cast heap leach Briggs Gold mine that produced 96 100 oz gold and 28 000 oz silver in 2001. Lower gold prices have forced Canyon Resources to re assess the mining of the North Briggs pit, as the current gold price cannot sustain stripping ratios. The company is evaluating the possibility of accessing the orebody using underground methods.
The world’s largest gold producer, AngloGold also has operations in the USA. Here AngloGold operates the Cripple Creek and Victor gold mines. Anglo Gold also has a 70% interest in the Jerrit Canyon gold mine with Meridian Gold Corporation. Jerrit Canyon.
AngloGold Ashanti Ltd
AngloGold Ashanti owns 67% of a joint venture with Golden Cycle Gold Corporation on the Cripple Creek and Victor Gold Mines located southwest of Colorado Springs in Colorado.
Barrick Gold Corporation
Barrick operates the majority of its gold mining operations in the USA with mines in Nevada, California and South Dakota.
Canyon Resources Corporation
Canyon Resources operates the Briggs gold mine in California.
Echo Bay Mines Ltd
Echo Bay has a 50% interrest in the Round Mountain gold mine in Nevada as well as the wholly owned McCoy/Cove gold mine in Nevada as well as the Kettle River gold mine in Washington State.
Golden Cycle Gold Corporation
Golden Cycle have a 33% interest in the Cripple Creek and Victor Gold Mines located in Colorado.
Hecla Mining Company
Kinross Gold Corporation
Kinross Gold operates the Fort Knox gold mine in Alaska.
Meridian Gold Inc.
Newmont Mining Corporation
The USA acts as a base for Newmont’s activities and has established itself on the Carlin trend in Nevada where it operates several mining complexes. Newmont operates 9 open pit and four underground mines plus 18 processing facilities. In southern California, Newmont also owns the Mesquite mine.
Placer Dome Inc.
The USA is considered as a base for Placer Dome’s gold production with several large scale operations in Nevada and Montana. In Nevada, Placer has a 60% interest in the large Cortez mine as well as wholly owning the Bald Mountain mine nearby. Placer Dome also operates the Golden Sunlight Mien in Montana. Placer Dome are evaluating the Getchell Gold mine in Nevada.
Rio Tinto Plc
Rio Tinto, through subsidiary Kennecot Minerals has interests in several major gold mining operations in the USA. Rio Tinto operates the Barneys Canyon Mine near Salt Lake City, has 40% interest in the Cortez – Pipeline mine in Nevada, 70% of the Greens Creek gold mine in Alaska and 51% of the Rawhide Mine in Nevada.
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