Top 10 deep open-pit mines27 September 2013
The deepest open pit mines are scattered geographically across the world unlike the deepest underground mines, which are mostly concentrated in South Africa. The majority of the deepest open pit operations in the world are copper producing mines. Mining-technology profiles the world's top ten deepest open pit mines currently active.
Bingham Canyon mine located south-west of Salt Lake City, Utah, US, is the deepest open pit mine in the world. The Bingham Canyon pit is more than 1.2km deep and approximately four kilometres wide.
The mine, which is owned and operated by Rio Tinto Kennecott, has been in production since 1906.
Also known as the Kennecott Copper Mine, Bingham Canyon produced about 179,317t of copper, 279,200 ounces of gold, 2.4 million ounces (Moz) of silver and 20 million pounds (Mlbs) of molybdenum in 2012.
The recoverable reserves at the open-pit exceeded 2.9Mt of copper, 2.8Moz of gold, 31Moz of silver and 240,000t of molybdenum as of December 2012.
Chuquicamata copper mine, situated 1,650km north of Santiago, Chile, is the second deepest open-pit mine in the world.
Chuquicamata, also known as the Chuqui open pit, is 4.3km long, three kilometres wide and more than 850m deep.
Chuquicamata copper mine has been in operation for more than a century. The mine is owned and operated by the Chilean state enterprise Codelco. The open-pit mine produced 443,000t of copper in 2011.
Feasibility study is underway to switch to underground production at Chuquicamata by the end of 2018. The ore reserve under the existing pit is estimated to be 1.7 billion tonnes grading at 0.7% copper. The underground development project is estimated to cost more than $4bn.
Escondida copper mine located in the Atacama Desert, Chile, ranks as the third deepest open-pit operation. Escondida copper mining operation consists of two open-pit mines, namely Escondida pit and Escondida Norte pit. The Escondida pit is 3.9km long, 2.7km wide and 645m deep. The Escondida Norte pit is 525m deep.
BHP Billiton is the operator of the mine with 57.5% interest. Rio Tinto holds 30% stake in the mine. Escondida is currently the world's largest copper producing mine.
It produced 1.1Mt of copper in the financial year ending June 2013, which accounts for about five percent of global copper production. Escondida's recoverable copper reserve was estimated to be more than 32.6Mt as of December 2012.
Udachny diamond mine located in the Eastern-Siberian Region of Russia is currently the fourth deepest open pit mine in the world. The Udachny pit is currently 630m deep. Mining at the Udachnaya kimberlite pipe has been going on since 1971.
The Udachny mine is owned and operated by Russia's state-owned company Alrosa. The mine produced ten million carats of diamond per year until 2011.
The probable contained diamond reserve at the open-pit was estimated to be 4.4 million carats as of July 2013.
The Udachny open pit operation is scheduled to close in 2014 with the opening of Udachny underground mine which is under construction. The contained diamond reserves for Udachny underground mining are estimated to be more than 108 million carats.
Muruntau mine in Uzbekistan, physically one of the largest open pit gold mines in the world, ranks as the fifth deepest open pit. The Muruntau open pit is 3.5km long and three kilometres wide. The depth of the mine has reached just more than 600m.
Muruntau was discovered in 1958. Mining operations started in 1967. Uzbekistan's Navoi Mining and Metallurgical Combinant own and operate the mine.
The final pit depth under the current mine plan is reported to be 650m, after which the mine will switch to underground operation.
Muruntau's contained gold reserves and resource including the historical production is reportedly estimated at 170Moz. The mine is known for its production capacity of about 2Moz of gold per year with averaging ore grade of 2.4g/t gold.
The Fimiston Open pit, also known as the Super Pit, located on south-east edge of Kalgoorlie, Western Australia, is the sixth deepest open-pit mine in the world. The gold producing open pit mine is 3.8km long, 1.5km wide and up to 600m deep.
The mine is owned and operated by Kalgoorlie Consolidated Gold Mines (KCGM), a 50-50 joint venture company comprised of Barrick Gold and Newmont Mining.
The mine produced 296,000oz of gold during the first half of 2013. The proven and probable reserves at Filmiston open pit as of December 2012 was estimated to be more than 8Moz.
Grasberg mine located in the Papua province of Indonesia currently ranks as the world's seventh deepest open pit operation. The miming operation at Grasberg consists of both open pit and underground mines. The Grasberg open pit is more than 550m deep. Grasberg is the largest gold mine in the world.
The mine also produces copper and silver. The Grasberg open pit operation started in 1990 and expected to continue up to 2016. The mine is operated by Freeport Indonesia (PTFI), a subsidiary of Freeport-McMoRan Copper & Gold (FCX) which owns 90.64% of the Grasberg mining operation.
The mine produced 862,000 ounces of gold and 695Mlbs of copper in 2012. The proven and probable ore reserve at Grasberg (open pit + underground) as of December 2012 was estimated at 2.424Mt grading 0.83g/t gold, 4.24g/t silver and one percent copper.
Betze-post pit, a part of Barrick Gold's Goldstrike operation located on the Carlin Trend, Nevada, US, is the eighth deepest open pit mine in the world. The gold producing open-pit is about 2.2km long and 1.5km wide. The depth of the pit is well above 500m.
Betze-Post is a truck-and-shovel operation. Large electric shovels are used for the open-pit mining. Goldstrike operation also includes Meikle and Rodeo underground mines located just north of the Betze-Post pit.
The total production from Goldstrike operation during the first half of 2013 was 417,000oz. The contained gold reserve at the Goldstrike open-pit as of December 2012 was estimated to be 8.93Moz (5.34Moz proven and 3.59Moz probable).
Nanfen iron mine
Nanfen open pit iron mine, located in Nanfen district of the Liaoning province, China, is approximately 500m deep. It is one of the largest open-pit metal mines in China.
Nanfen open pit mine is owned and operated by Benxi Iron and Steel Corporation (Benxi Steel). The mine produced more than 100 million tonnes of iron ore in 2011. It was the maximum iron ore output by a single Chinese mine per year.
A plan for starting underground mining operation at Nanfen has been underway since 2011 as maintaining the mine slope stability is becoming difficult with the gradual increase of the pit's depth.
Aitik open pit mine located about 60km north of the Arctic Circle in Northern Sweden is currently 430m deep.
The open pit is expected to reach a final depth of 600m. Aitik is the largest copper mine in Sweden. The mine also produces silver and gold.
The Aitik mine was discovered in 1930. The open pit mine is owned and operated by Boliden. Production from the mine started in 1968 with a modest production rate of two million tonnes of copper ore a year.
The mine produced 34.3 million tonnes of ore in 2012. The mineral output during the year included 270,000t of concentrate, 67,100t of copper, 51.7t of silver and 1.9t of gold.
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