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Copper mining in Chile

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Production trends in the top five copper-producing countries, 1950-2012
Location of the five largest copper mines by copper production[1] and the two active custom copper smelters of Chile. Note that more copper smelters exist but these are usually integrated within the mines.

Chile is the world's largest producer of copper[2] and has been so uninterruptedly since 1983. This activity provides a substantial part of the Chilean state's revenue: slightly less than 6% in 2020, with state-owned copper company Codelco alone generating 2.6% of state revenue.[3][A]

Mining of copper in Chile is done chiefly on giant low-grade porphyry copper deposits which are mined by the state-owned company Codelco and private companies owned by national and international companies like Antofagasta Minerals and BHP. Some mines are developed jointly by two or more companies, as is the case of Escondida (BHP, Rio Tinto and JECO Corp) and Collahuasi (Glencore and Anglo American plc). Copper is also the main product of small-scale mining in Chile, with about 95% of small-scale miners working in copper mining.[4][B] One estimate puts the number of active copper mines in Chile in 2023 at 67.[1] In the 2005–2024 period 81–89% of the annual copper production in Chile has been mined in open pits and the remaining in underground mines.[5]

The amount of copper mined in Chile has remained relatively constant at 5,212 to 5,831 thousand tons of copper yearly in the 2005–2024 period but given increased copper mining outside Chile the country's share of the world's produce has dropped from 36% to 24% in the same period.[5] Also in the same period 36% to 72% of the gold and more than half of the silver produced annualy in Chile was a by-product of copper mining.[5] The grade of copper ores mined in Chile has dimished since 2001 due to depletion and increased profitability of low-grade ore due to high copper prices.[6] The amount of water consumed and greenhouse gases emitted per ton copper produced has also diminished since 2001.[6][C]

Most copper mined in Chile is exported to China. Far behind China, other important export destinations for Chilean copper are Japan, United States and South Korea.[7] In the 2020s unrefined copper concentrate have stood for about 58 of the value of Chilean copper exports, while copper cathode refined in Chile stands for the remaining 38.

The governance of copper mining in Chile is done by non-overlapping bodies; COCHILCO, ENAMI, the National Geology and Mining Service (SERNAGEOMIN) and the Ministry of Mining.[4] SONAMI and Consejo Minero are corporate guilds of mining companies in Chile.[8]

Largest copper mines in Chile by production[1]
Mine Type Tons of copper
(× 1000)
Year of
production
Year of
opening
Projected
year of
closure
Owners Sources
Collahuasi Open-pit 563.39 2023 1999 2106 Glencore (44%)
Anglo American (44%)
JCR (12%)
[1][9]
Radomiro Tomic Open-pit 290.14 2023 1997 2065 Codelco [1]
Escondida Open-pit 882.1 2023 1990 2078 BHP (57.5%)
Rio Tinto (30%)
JECO Corporation (10%)
JECO 2 Ltd (2.5%)
[1][10]
Los Pelambres Open-pit 305.62 2023 1999 2035 Antofagasta Minerals [1]
El Teniente Underground 397.32 2023 1908 2072 Codelco [1]

Geology

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Porphyry copper deposits of the same age in Chile occur in elongated geographical patterns which are termed metallogenic belts. Five metallogenic copper belts have been identified by geologists in Chile. The main two of these are the Late Eocene-Oligocene belt in the far north and the Middle Miocene-Early Pliocene belt in north-central Chile.[11][12] Collahuasi, El Abra, Chuquicamata, Escondida and Radomiro Tomic lie in the Late Eocene-Oligocene belt and Los Pelambres, Los Bronces and El Teniente in the Middle Miocene-Early Pliocene belt.[11][12][D] Other metallogenic belts containing porphyry copper deposits are a discontinous Cretaceous belt and the Early-Middle Miocene belt, both of which are located in northern Chile.[11] These ores formed episodically during the span of the Andean orogeny except for the Jurassic when the orogeny was not contractional but extensional.[11] The Late Eocene-Oligocene belt is the one hosting most copper resources.[11] Within this belt the copper deposits of Chuquicamata, Collahuasi, El Abra, El Salvador, Escondida and Potrerillos are aligned on top of the Domeyko Fault.[11][13]

Various authors have indicated that the occurrence of intersections between continent-scale traverse fault zones and arc-parallel structures are associated with porphyry formation.[14] In Chile this has been pointed out to be the case of Escondida, Los Bronces and El Teniente porphyry copper deposits each of which lies at the intersection of two fault systems.[15][16]

A few copper deposits in Chile are labelled "exotic" as they originate from kilometer-scale lateral migration of copper-rich fluids originating in porphyry copper deposits.[17][18]

Refining and smelting

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View of Codelco's Caletones smelter as of 2015 that serves El Teniente mine.

The main product of Chilean copper mining is copper concentrate (i.e. the stage of the ore before smelting). In 2024, this represented 50.9% of the value of Chilean mining products exports, while refined copper made up 33%,[19] down from 34.9% in 2023. This reduction follows a long-term trend of diminishing smelting capacity in Chile.[19][20][E]

Processing is done in a number of copper smelters, some of which rank among the world's largest in term of capacity. Large copper mines have their own smelters, but there are also the custom copper smelters[F] of Altonorte in La Negra and Paipote near Copiapó, operated by Glencore and ENAMI respectively.[21]

Since the 1990s no new copper smelters have been built in Chile.[22] Following the closure of Codelco's Fundición Ventanas in central Chile in 2022, there have been public discussions on building a large new copper smelter in Chile.[20] Antofagasta Region and Atacama Region have been proposed by Chilean industry experts as viable replacement sites.[23] Others have argued for keeping smelting in the Valparaíso Region, given the existence of nearby mines.[23] While some argue the replacement plant should be near the coast, the inland sites of Chuquicamata and El Salvador have also been proposed as alternatives.[23] The president of the National Mining Society (Sonami), Diego Hernández, estimates the construction period for a new smelter plant to be 5 to 7 years.[23] A 2024 study identified Antofagasta Region as the best place for a new copper smelter, due to logistical advantages and an existing and expandable supply of copper concentrate from nearby mines.[24]

History

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Copper has been mined for centuries at Chuquicamata, as evidenced by the 1899 discovery of the "Copper Man," a mummy dated to c. 550 A.D. The mummy was found in an ancient mine shaft, apparently trapped by a rockfall.[25] About 74 km northeast of Copiapó in Viña del Cerro the Incas had one of their largest mining and metallurgy centres at Qullasuyu.[26] There is evidence of gold, silver and copper metallurgy at the site, including the production of bronze.[26]

Chilean copper mining of high-grade oxidized copper minerals and melting with charcoal produced 80,000 to 85,000 tons of copper in the 1541–1810 period.[27]

The introduction of reverberatory furnaces to Chile around 1830 by Charles Saint Lambert[28] revolutionized Chilean copper mining.[29] To this came the improvements of transport caused by the development of railroads and steam navigation.[30] Prospector José Tomás Urmeneta discovered the mineral source of Tamaya in 1850, and this became one of Chile's main copper mines.[29] All of this enabled Chile to supply 18% of the copper produced worldwide in the 19th century, and from the 1850s to the 1870s the country was the world's top producer.[31][32] In some years Chile's copper production made up about 60% of the world's output ,and its export tariffs made up more than half the state's income.[33] In Chuquicamata, which was to become Chiles largest copper mine in the 20th century, Chilean and English companies mined the brochantite veins from 1879 to 1912.[34]

View of Sewell, a town created to serve El Teniente during the early days of the large-scale copper mining.
World copper production, 1946. Click to enlarge.
View of Chuquicamata mine in 1983. For most of the 20th century this was the most productive copper mine in Chile.

By the late 19th century the Chilean mining industry once again lagged behind technological developments elsewhere[G] contributing to the drop of its share of the world production to 5–6% in the 1890s. Similar shares continued in the 1900s and 1910s, reaching a low of 4.3% in 1914.[31][36][35] Up to the 1940s and 1950s there was also a notable lack of major copper exploration efforts by large mining companies that relied on purchasing prospects already known from the activity of small-scale miners and pirquineros.[37]

Large-scale mining era

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Modern large-scale copper mining in Chile emerged though technological transfer and capital investment from the United States in three mines; El Teniente (1904), Chuquicamata (1912), and Potrerillos (1920).[38][39] The Guggenheims that owned El Teniente sold 95% of the shares of this mine to Kennecot Copper in 1915 and then sold in 1923 51% of their share in Chuquicamata to Anaconda Copper.[40] With the onset of the Great Depression in 1929 copper prices plummeted and unemployment among miners in Chile became rife.[41]

After the United States entered the Second World War in 1941 maximum prices for copper were imposed impacting mining and generating large revenue losses for Chile.[42] During the Korean War (1950–1953) copper mining in Chile was again affected by price caps imposed by the United States.[43] The Chilean state overhauled its relationship to foreign large-scale copper mining with its Ley de Nuevo Trato law of 1955.[44] This new law sought to reward investments in copper mining by offering decreasing taxes if production increased.[44] Despite this overhaul, new mining taxes were added in 1961.[45]

The existing institutions supporting small-scale mining —Empresa Nacional de Fundiciones and Caja de Crédito Minero— were reorganized in 1960 into the new state-owned company ENAMI.[46] This new company came to own to two custom smelters, Paipote which it inherited and Ventanas which it inaugurated in 1964.[46]

In 1969 the Chile negotatiated for the state-owned company Codelco the purchase of a 51% stake of each of the subsidary companies of Anaconda Copper operating in the mines Chuquicamata and El Salvador.[47] In the same negotiation Chile was promised the purchase of the remaining 49% of the stakes on December 1972.[47]

Investments in copper mining concentrated in Chile in the 1980s and 1990s, as copper mining in other countries faced problems like political instability (Peru), increased environmental requirements (developed countries) and overall disinterest in foreign investment in a nationalized mining industry (Zaire, Zambia).[48]

In 1987 Chile introduced the Copper Stabilization Fund, a fund aimed to stabilize the income of Codelco given the volatility of copper prices.[49]

Notes

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  1. ^ From 2001 to 2014 Codelco alone stood for 10% of the state's income.[3]
  2. ^ The fact that most small-scale mining in Chile focus on copper, which means handling large volumes difficult to smuggle or hide has been thought to be a contributing factor to the low levels of illegal mining in Chile.[4]
  3. ^ While in the 2001–2015 period mill plant concentrators have become more efficient in requiring less water for the same amount of processed mineral, over-all lower ore grades processed have led to more water demand in the flotation facilities.[6]
  4. ^ When not considering the other three belts, these two belts are sometimes referred to as the Paleogene belt and the Neogene belt.[12]
  5. ^ In the 2013-2023 period the copper smelting capacity in China and Zambia has increased while the capacity in Chile and the United States has decreased.[20] China has by far the largest capacity of copper smelting with over half of the world's total. Besides the previously mentioned countries, other countries with a significant installed cathode production capacity as of 2023 were (as percentages of the world total) Japan (8%), Russia (5%), Poland (3-4%) and Bulgaria (3-4%).[20]
  6. ^ A custom copper smelter is one receiving or open to receive ores from multiple mines. Thus, these smelters tend to be less fine-tuned[clarification needed] than smelters integrated with specific mines. Custom smelters tend also to be located at strategic locations, such as near port faciilities or at important crossroads in mining districts.
  7. ^ e.g. flotation, leaching, mechanization and large-scale open-pit mining.[35]

References

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  1. ^ a b c d e f g h "The five largest copper mines in operation in Chile". Mining Technology. 2024-06-24. Retrieved 2025-04-12.
  2. ^ Copper production in 2024 by USGS
  3. ^ a b Corvera Vergara, María Teresa (2021-06-02). Aporte de la minería del cobre a las arcas fiscales: Proyección para el año 2021 (PDF) (Report) (in Spanish). Biblioteca del Congreso Nacional de Chile.
  4. ^ a b c Scholvin, Sören; Atienza, Miguel. "La formalización de la pequeña minería en Chile: logros y desafíos de la Empresa Nacional de Minería (ENAMI)". Investigaciones Geográficas (in Spanish). 66: 1–13.
  5. ^ a b c Cifras actualizadas de la minería (Report) (in Spanish). Consejo Minero. 2025-03-01. pp. 5, 29, 31–32.{{cite report}}: CS1 maint: date and year (link)
  6. ^ a b c Lagos, Gustavo; Peters, David; Videla, Alvaro; Jara, José Joaquín. "The effect of mine aging on the evolution of environmental footprint indicators in the Chilean copper mining industry 2001–2015". Journal of Cleaner Production. 174: 389–400.
  7. ^ International Copper Study Group, The World Copper Factbook 2024 (PDF), p. 53, archived (PDF) from the original on 19 December 2024, retrieved 19 December 2024
  8. ^ Ulloa Urrutia et al. 2017, p. 50.
  9. ^ "Collahuasi". Consejo Minero (in Spanish). Retrieved 2025-04-11.
  10. ^ "Minera Escondida". Consejo Minero (in Spanish). Retrieved 2025-04-11.
  11. ^ a b c d e f Camus, Francisco; Dilles, John H. (2001). "A Special Issue Devoted to Porphyry Copper Deposits of Northern Chile: preface". Economic Geology. 96 (2): 233–237.
  12. ^ a b c Piquer, José; Sanchez-Alfaro, Pablo; Pérez-Flores, Pamela (2021). "A new model for the optimal structural context for giant porphyry copper deposit formation". Geology. 49 (5): 597–601. doi:10.1130/G48287.1.
  13. ^ Robb, Laurence (2007). Introduction to Ore-Forming Processes (4th ed.). Malden, MA, United States: Blackwell Science Ltd. p. 104. ISBN 978-0-632-06378-9.
  14. ^ Sillitoe, R.H., "Porphyry Copper Systems". Economic Geology, 2010. 105: pp. 3–41.
  15. ^ Richards, Jeremy P.; Boyce, Adrian J.; Pringle, Malcolm S. (2001). "Geologic Evolution of the Escondida Area, Northern Chile: A Model for Spatial and Temporal Localization of Porphyry Cu Mineralization". Economic Geology. 96: 271–305.
  16. ^ Piquer Romo, José Meulen; Yáñez, Gonzálo; Rivera, Orlando; Cooke, David (2019). "Long-lived crustal damage zones associated with fault intersections in the high Andes of Central Chile". Andean Geology. 46 (2): 223–239. doi:10.5027/andgeoV46n2-3108. Retrieved June 9, 2019.
  17. ^ Mortimer B., Credic; Munchmeyer F., Carlos; Urqueta D., Igor (1978). "Emplazamiento del yacimiento Exótica". Revista Chilena de Geología (in Spanish). 6: 41–51.
  18. ^ Sillitoe, Richard H. (2005). "Supergene Oxidized and Enrioched Porphyry Copper and Related Deposits". Economic Geology: 723–768. doi:10.5382/AV100.22.
  19. ^ a b Becerra, Mauricio (2025-02-19). "Concentrados vuelven a superar exportación de cobre refinado en Chile". El Ciudadano (in Spanish).
  20. ^ a b c d Pedrals, Jorge (2023-06-17). "La compleja discusión sobre una nueva fundición en Chile". Minería Chilena (in Spanish). Retrieved 2025-04-22.
  21. ^ Costabal M., Francisco (2015-06-10). Fundiciones de Cobre en Chile (PDF) (Report) (in Spanish). SONAMI. Retrieved 2025-03-23.
  22. ^ "Una nueva fundición para Chile. Posible y necesaria". CESCO (in Spanish). 2023-07-17. Retrieved 2025-04-22.
  23. ^ a b c d Toro, Daniela; Munita, Ignacia (2022-06-25). "Cierre de fundición Ventanas: El intrincado debate por dónde instalar una nueva planta y los costos asociados". Emol (in Spanish). Retrieved 2022-06-26.
  24. ^ Pacheco Zamora, Sebastián Patricio. Nueva Fundición de Cobre en Chile (PDF) (Industrial Engineering thesis) (in Spanish). University of Chile. Retrieved 2025-04-21.
  25. ^ Fuller, David R. (2004). "The production of copper in 6th century Chile's chuquicamata mine". JOM. 56 (11): 62–66. Bibcode:2004JOM....56k..62F. doi:10.1007/s11837-004-0256-6. S2CID 137666853.
  26. ^ a b Cortés Lutz, Guillermo (2017). Chañarcillo, cuando de las montañas brotó la plata (PDF). Cuadernos de Historia (in Spanish). Vol. II. Museo Regional de Atacama. p. 4.
  27. ^ Maksaev, Víctor; Townley, Brian; Palacios, Carlos; Camus, Francisco (2006). "6. Metallic ore deposits". In Moreno, Teresa; Gibbons, Wes (eds.). Geology of Chile. Geological Society of London. pp. 179–180. ISBN 9781862392199.
  28. ^ John Mayo; Simon Collier (3 September 1998). Mining in Chile's Norte Chico: Journal of Charles Lambert, 1825-1830 (Dellplain Latin American Studies). Westview Press Inc. ISBN 978-0-813-33584-1.
  29. ^ a b Sagredo 2005, p. 277.
  30. ^ Camus 2005, p. 282.
  31. ^ a b Sutulov 1975, p. 3.
  32. ^ Camus 2005, p. 233.
  33. ^ Sagredo 2005, p. 280.
  34. ^ Ossandon, Guillermo; Freraut, Roberto; Gustafson, Lewis; Lindsay, Darryl; Zentilli, Marcos (2001). "Geology of the Chuquicamata Mine: A Progress Report". Economic Geology. 96 (2): 249–270. Bibcode:2001EcGeo..96..249O. doi:10.2113/gsecongeo.96.2.249. S2CID 128812977.
  35. ^ a b Camus 2005, p. 236.
  36. ^ Sagredo 2005, p. 290.
  37. ^ Camus 2005, p. 241.
  38. ^ Sutulov 1975, p. 31.
  39. ^ Salazar & Pinto 2002, pp. 124–125.
  40. ^ Sutulov 1975, p. 33.
  41. ^ Sutulov 1975, p. 35.
  42. ^ Sutulov 1975, p. 36.
  43. ^ Sutulov 1975, p. 37.
  44. ^ a b Sutulov 1975, p. 39.
  45. ^ Sutulov 1975, p. 40.
  46. ^ a b Sutulov 1975, p. 42.
  47. ^ a b Sagredo 2005, p. 291.
  48. ^ Valenzuela Rabí, Iván (2014). "El boom minero de los 90" [The mining boom of the 90s]. La Gran Minería en Chile [Large Scale Mining in Chile] (in Spanish). Ocho Libros. pp. 135–152. ISBN 9789563351927.
  49. ^ Ceballos & Tilton 2005, p. 295.

Bibliography

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