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Chuquicamata, or "Chuqui" as it is more familiarly known, is a big open pit copper mine in the north of Chile, 215 kms northeast of Antofagasta and 1,240 kms north of the capital, Santiago. For many years it was the mine with the largest annual production in the world but was recently overtaken by Minera Escondida. Nevertheless it remains the mine with by far the largest total production of approximately 29 million tonnes of copper to the end of 2007 (excluding Radomiro Tomic). Despite over 90 years of intensive explotiation it remains one of the largest known copper resources. Its open pit is one of the largest at 4.3 km long, 3 km wide and over 850 m deep and its smelter and electrolytic refinery (855,000 tonnes p.a.) are amongst the world's largest. Chuquicamata is also a significant producer of molybdenum.

Chuquicamata is now amalgamated with the operating Radomiro Tomic mine to the north (but still on the same mineralised system), the developing Alejandro Hales mine just to the south (formerly Mansa Mina, a slightly impolite description) and the recently discovered 'Toki cluster' of copper porphyries to form the Codelco Norte division of Codelco.

Pre History
There are several versions of the meaning of Chuquicamata. The most widely known seems to be that it means the limit (camata) of the land of the Chucos (chuqui). Another says that it means metal (chuqui) tipped wooden (camata) spear. A third says that it means the distance (camata) that a spear (chuqui) was thrown by an Atacameño to determine the size of the copper orebody that a god intended to give him as a reward. Yet another theory is that it means 'Pico de Oro' or 'Peak of Gold'.

Copper has been mined for centuries at Chuquicamata as was shown by the discovery in 1898 of "Copper Man", a mummy dated at about 550 A.D. which was found trapped in an ancient mine shaft by a fall of rock. It is also said that Pedro de Valdivia obtained copper horseshoes from the natives when he passed through in the early 16th Century.

Mining activity was, at best, sporadic until the War of the Pacific when Chile annexed large areas of both Peru and Bolivia north of its old border, which included Chuquicamata. There was then a great influx of miners into the area drawn in by 'Red Gold Fever' (La Fiebre del Oro Rojo) and soon Chuquicamata was covered with mines and mining claims, over 400 at one point. It was a wild and disorganised camp. Title to claims was often in doubt due to the defective 1873 Mining Code and the capture of Calama by the 1892 Civil War rebels who confiscated mines belonging to loyalists and further complicated titles. Many of the miners lived in makeshift and lawless shanty towns around the mines, including Punta de Rieles, Placilla and Banco Drummond, which provided alcohol, gambling and prostitution and where murder was almost a daily occurance. As late as 1918 the army had to be sent in to keep order. They were eventually buried under the waste dumps to the east of the mine.

These early operations mined veins such as the Zaragoza and Balmaceda, which were high grade with values up to 10-15% copper, and disregarded the low grade disseminated ore. One attempt was made to process the low grade ore in 1899-1900 by Norman Walker, a partner in La Compañia de Cobres de Antofagasta, but it failed leaving the comany deeply in debt. However, mining never really developed satisfactorily in the early days because of the lack of water, the isolation and lack of communications, lack of capital and fluctuations in the copper price. Nevertheles larger mining companies eventually emerged, organised as commercial rather than mining operations to avoid the imperfections of the mining code, and started to buy up and consolidate the small mines and claims.

The Modern Mine
The modern era started when the American engineer Bradley finally developed a method of working low grade oxidised copper ores. In 1910 he approached the lawyer and industrialist Albert C Burrage who sent engineers to examine Chuquicamata. their reports were good and in April 1911 he started to buy up mines and claims, mainly from the larger mining companies, in association with Duncan Fox y Cia., an English entrepreneur. Unfortumately Burrage did not have the capital to develop a mine so he approached the Guggenheim Brothers. They examined his claims and estimated reserves at 690 million tonnes grading 2.58% copper. The Guggenheims also had a process for treating the low grade ores developed by E A Capellen Smith and were immediately interested, organised the Chile Exploration Company (Chilex)in January 1912 and eventully bought bought out Burrage for US$25 million in Chilex stock.

Chilex then went ahead wih the development and construction of a mine on the eastern section of the Chuquicamata field (It acquired the remainder gradually over the next 15 years) and a 10,000 tons per day leaching plant which was planned to produce 50,000 tons of electrolytic copper annually. Amongst the equipment purchased were steam shovels from the Panama Canal  A port and oil fired power plant were built at Tocopilla, 90 miles to the west and an aquaduct was constructed to bring water in from the Andes  Production started on May 18th 1915. Actual production rose from 4345 tonnes in the first year to 50,400 tonnes in 1920 and 135,890 tonnes in 1929 before the Depression hit and demand fell.

Production from the capping of oxidised minerals, which required mere leaching in sulphuric acid to dissolve the copper and the recovery of the copper by electrolysis was the sole means of production until the 1950's. However their gradual depletion forced th construction of a mill, flotation plant and smelter to treat the underlying secondary sulphides. These have been steadily expanded until recently it was producing over 600,000 tonnes of copper annually, both as refined cathodes and as concentrates for treatment elsewhere.

The Guggenheims gave up control of the mine in 1923 when they sold 51% to Anaconda, who acquired most of the remainder in 1929. Anaconda ran the mine until the 1960's when the Chilean state acquired a 51% holding in the "Chilenization" of the copper industry. In 1971 the mine was nationalised and in 1976 was incorporated into the newly formed Codelco (Corporacion Nacional del Cobre de Chile). It is now the major part of the Codelco Norte division

The Future
Chuqui has stated for some years that it will go to underground mining below the main open pit in the fairly near future and at a symposium in Santiago in 2007 (Minería de Excelencia hacia el Bicentenario) the company gave a detailed account of planning to that point and their mining plan for the sulphide mill until 2035.

However, with the copper price currently (mid 2008) in the US$3.50/4.00 per pound region, every copper mine in the world will be reviewing its reserves, resources and mining plan and the schedule given in the 2007 paper may well now be changed. Nevertheless, the future of the mine may well go along the lines given at the symposium but possibly with a longer life for the open pit.

The symposium envisages a gradual rundown of production from the main open pit to closure in 2020. Any shortfall will be made up from sulphides from Radomiro Tomic and the Alejandro open pit. Eventually, by 2030, the mill will be supplied entirely by the mine below the open pit and the Alejandro Hales undergroung mine