Minera Escondida (which means 'hidden' in

Spanish Spanish might refer to: * Items from or related to Spain: **Spaniards are a nation and ethnic group indigenous to Spain **Spanish language, spoken in Spain and many countries in the Americas **Spanish cuisine **Spanish history **Spanish culture ...

) is a mining company that operates two

open pit Open-pit mining, also known as open-cast or open-cut mining and in larger contexts mega-mining, is a surface mining technique that extracts rock or minerals from the earth. Open-pit mines are used when deposits of commercially useful ore or ...

copper Copper is a chemical element; it has symbol Cu (from Latin ) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkish-orang ...

mines in the

Atacama Desert The Atacama Desert () is a desert plateau located on the Pacific Ocean, Pacific coast of South America, in the north of Chile. Stretching over a strip of land west of the Andes Mountains, it covers an area of , which increases to if the barre ...

, 170 km southeast of

Antofagasta Antofagasta () is a port city in northern Chile, about north of Santiago. It is the capital of Antofagasta Province and Antofagasta Region. According to the 2015 census, the city has a population of 402,669. Once claimed by Bolivia follo ...

in northern

Chile Chile, officially the Republic of Chile, is a country in western South America. It is the southernmost country in the world and the closest to Antarctica, stretching along a narrow strip of land between the Andes, Andes Mountains and the Paci ...

. It is currently the highest producing copper mine in the world. Its 2007 production of 1.483 million tons of the metal was worth US$10.12 billion, mainly as metal in concentrate, but some as cathode, and was 9.5% of world output and 26% of Chilean production, according to the US Geological Survey's preliminary estimates of 2007 world mine output.

Overview

It is so called because the main orebody does not outcrop on the surface, but is 'hidden' by hundreds of metres of practically barren overburden. The lower open pit in the satellite image on the right is the main Escondida mine, but the upper two are

Barrick Gold Barrick Mining Corporation is a mining company that produces gold and copper. It has mining operations and projects in Argentina, Canada, Chile, Côte d'Ivoire, Democratic Republic of the Congo, Dominican Republic, Ecuador, Egypt, Mali, Pakista ...

's Zaldívar mine. The second Escondida open pit, Escondida Norte, had not been established when the image was taken, but is now immediately to the right (east) of the larger Zaldívar pit. Escondida produces mainly copper concentrates, which are piped as a slurry down to the port of Coloso, where they are dewatered before shipping, and a smaller proportion of cathode copper from the leaching of both oxide and low grade sulfide ore. It also produces gold and silver. The mine is owned 57.5% by

BHP BHP Group Limited, founded as the Broken Hill Proprietary Company, is an Australian multinational mining and metals corporation. BHP was established in August 1885 and is headquartered in Melbourne, Victoria. As of 2024, BHP was the world� ...

; 30% by Rio Tinto; and 10% by JECO Corp, a Japanese joint venture established in 1988 by

Mitsubishi The is a group of autonomous Japanese multinational companies in a variety of industries. Founded by Yatarō Iwasaki in 1870, the Mitsubishi Group traces its origins to the Mitsubishi zaibatsu, a unified company that existed from 1870 to 194 ...

, with 70% ownership; Nippon Mining & Metals, with 20% ownership;

Mitsubishi Materials , or MMC, is a Japanese company. It is a manufacturer of cement products, copper and aluminum products, cemented carbide tools, and electronic materials. It is one of the core companies of Mitsubishi Group. The company is listed on the Tokyo St ...

with a 10% share, adding 2.5% ownership by JECO 2 Ltd., another

joint venture A joint venture (JV) is a business entity created by two or more parties, generally characterized by shared ownership, shared returns and risks, and shared governance. Companies typically pursue joint ventures for one of four reasons: to acce ...

incorporated in 2010, "to increase their ownership in Escondida by 2.5%," with an ownership structure of 50% Mitsubishi Corp, 40% Nippon Mining & Metals, and 10% Mitsubishi Materials. Escondida is managed by a seven-person Owners' Council designated by the four owners, and is both the largest known copper reserve and the largest foreign investment in Chile. 2006 financial reports showed a cumulative investment of US$5.64 billion,''Minera Escondida Annual Report 2006''
and at year end June 2013, Escondida accounted for approximately 5 percent of all copper production.

History

In 1978, J David Lowell proposed an exploration program along the

porphyry Porphyry (; , ''Porphyrios'' "purple-clad") may refer to: Geology * Porphyry (geology), an igneous rock with large crystals in a fine-grained matrix, often purple, and prestigious Roman sculpture material * Shoksha porphyry, quartzite of purple c ...

copper belt between

Chuquicamata Chuquicamata ( ; referred to as Chuqui for short) is the largest open-pit mining, open pit copper Mining, mine in terms of excavated volume in the world. It is located in the north of Chile, just outside Calama, Chile, Calama, at above sea level. ...

in the north and El Salvador in the south.''Yacimientos Metaliferous de Chile, Ruiz Fuller & Peebles, Santiago 1988'' Minera Utah de Chile and Getty Mining (Chile) formed a joint venture to carry it out. On March 14, 1981, 'Pozo 6' the last scheduled borehole in the program, hit 52 metres of 1.51% copper at a depth of 240 metres and discovered the main Escondida orebody. More holes were drilled to delineate the orebody and a shaft was sunk to provide bulk samples for metallurgical testing. Construction of the mine started in 1988, which including the stripping of over 180 million tonnes of waste to get to the orebody. The Los Colorados concentrator started up at 35,000 tonnes per day in November 1990, and the first concentrate shipment was made at the end of the year. Expansion has been steady since then. In 1994, an ammonia leach plant to produce copper cathode from a portion of the concentrates was started up in Coloso, but was not economic and closed down four years later. In 1998, the oxide ore leaching plant was started up, which now has a capacity of 150,000 tonnes of copper cathode annually. Also in 1998, the Los Colorados concentrator was expanded to 120,000 tonnes per day. A second concentrator, the 110,000 tonnes per day Laguna Seca mill, started up in 2002, the Escondida Norte pit started production in 2005, and in 2006 a sulphide bioleach plant with an annual capacity 180,000 tonnes of cathode started up, as did a desalination plant in Coloso. Ownership changed when BHP acquired Utah Mining and then

Texaco Texaco, Inc. ("The Texas Company") is an American Petroleum, oil brand owned and operated by Chevron Corporation. Its flagship product is its Gasoline, fuel "Texaco with Techron". It also owned the Havoline motor oil brand. Texaco was an Independ ...

acquired

Getty Oil Getty Oil Company was an American oil marketing company with its origins as part of the large integrated oil company founded by J. Paul Getty. They went defunct in 2012. History J. Paul Getty incorporated Getty Oil in 1942. He had previously ...

and sold off its mineral interests. BHP bought these and then sold a 30% interest to Rio Tinto and 10% to JECO. It subsequently sold 2.5% to the

International Finance Corporation The International Finance Corporation (IFC) is an international financial institution headquartered in Washington, D.C. and a member of the World Bank Group that offers investment, advisory, and asset-management services to encourage private ...

Escondida Mine

Chilean economy and the world copper market

Escondida has become an important part of the Chilean economy. According to the CIA World Factbook, the mine's 2007 sales of US$10.21 billion were 4.3% of estimated 2007 GDP of US$234.4 billion and about 15% of exports. At the end of 2006, the company employed directly some 2,951 workers and 3,158 contractors The average copper price in 2007 rose to US$3.23/lb compared with the mine's total direct costs of only 60.8 cents/lb, which fell partly as a result of sharply lower treatment and refining costs charged by smelters. The operation was thus highly profitable and paid US$2.2 billion in taxes to the Chilean treasury. As a result of its considerable size relative to the world copper market, developments at Escondida can have dramatic effects on the world copper price as was shown by its gyrations during the strike in August 2006. The strike was called because the workers felt they were not sharing in the very high profits being made by the company on the back of the record copper price.''Mine closure lifts copper price''
The workers initially demanded a 13% pay rise plus a bonus of $30,000, but eventually settled for a 5% increase, a $17,000 bonus and a number of other minor benefits. The company managed to keep production at 40% of normal levels, but the union eventually blockaded the road to the mine on 16 August. On 18 August, Escondida declared ''force majeure'' and stopped production. Arturo Martinez, the chairman of the '' Central Unitaria de Trabajadores'', (CUT, an association of Chilean trade unionists) met with the Escondida workers on 17 August 2006, and said that "what is happening at Escondida puts back onto the agenda a new nationalisation of copper, ''lo que ocurre en Escondida pone a la orden del día una nueva nacionalización del cobre''.Workers of the Escondida copper mine are making demands of the company''
'' ADN Mundo'',

References

External links