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.
It was the start of copper mining by the Chile Exploration Company of the Guggenheim Group.
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.

Since Burrage did not have the capital to develop a mine, 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 Elias Anton Cappelen Smith and were immediately interested, organised the Chile Exploration Company (Chilex) in January 1912 and eventually bought out Burrage for US$25 million (or $662 million today) in Chilex stock.
E. A. Cappelen Smith, consulting metallurgist for M. Guggenheim's Sons, worked out the first process for the treatment of Chuquicamata copper oxide ore about 1913, and directed a staff of engineers operating a pilot plant at Perth Amboy, New Jersey, on three shifts for an entire year.

Chilex then went ahead with the development and construction of a mine on the eastern section of the Chuquicamata field. (
It acquired the remainder of the field gradually over the next 15 years).
The 10,000 tons per day leaching plant 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 an oil-fired power plant were built at Tocopilla, 140 km (90 mi) to the west and an aqueduct was constructed to bring water in from the Andes.
Production started on May 18, 1915.
Actual production rose from 4,345 tonnes in the first year to 50,400 tonnes in 1920 and 135,890 tonnes in 1929 before the Depression hit and demand fell.

The Guggenheims sold the mine to Anaconda Copper in 1923.

Production for many years came from the oxidised capping of the orebody which merely required leaching and then electrowinning of the copper, but by 1951 the oxidised reserves were largely exhausted and the company built a mill, flotation plant and smelter to treat the huge reserves of underlying supergene copper sulfides.
These secondary sulfides arise from the leaching of the overlying ore and its re-deposition on and replacement of the deeper primary (hypogene) sulfides.

In 1957 the Exotica deposit (South Mine) was discovered beneath tailings, which turned out to be the largest known deposit of exotic copper.
 This led Anaconda to build an oxide plant, concentrator, smelter, refinery, and town, all next to the mine, plus a power plant in Tocopilla.
 However, in 1971, the mine was nationalized and operations were then assumed by CODELCO.

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 Tomić).
Despite over 90 years of intensive exploitation it remains one of the largest known copper resources.
Its open pit is the world's largest at 4.3 km (2.7 mi) long, 3 km (1.9 mi) wide and over 900 m (3,000 ft) 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 Tomić 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.
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. It was the start of copper mining by the Chile Exploration Company of the Guggenheim Group. 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.
Since Burrage did not have the capital to develop a mine, 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 Elias Anton Cappelen Smith and were immediately interested, organised the Chile Exploration Company (Chilex) in January 1912 and eventually bought out Burrage for US$25 million (or $662 million today) in Chilex stock. E. A. Cappelen Smith, consulting metallurgist for M. Guggenheim's Sons, worked out the first process for the treatment of Chuquicamata copper oxide ore about 1913, and directed a staff of engineers operating a pilot plant at Perth Amboy, New Jersey, on three shifts for an entire year.
Chilex then went ahead with the development and construction of a mine on the eastern section of the Chuquicamata field. (It acquired the remainder of the field gradually over the next 15 years). The 10,000 tons per day leaching plant 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 an oil-fired power plant were built at Tocopilla, 140 km (90 mi) to the west and an aqueduct was constructed to bring water in from the Andes. Production started on May 18, 1915. Actual production rose from 4,345 tonnes in the first year to 50,400 tonnes in 1920 and 135,890 tonnes in 1929 before the Depression hit and demand fell.
The Guggenheims sold the mine to Anaconda Copper in 1923.
Production for many years came from the oxidised capping of the orebody which merely required leaching and then electrowinning of the copper, but by 1951 the oxidised reserves were largely exhausted and the company built a mill, flotation plant and smelter to treat the huge reserves of underlying supergene copper sulfides. These secondary sulfides arise from the leaching of the overlying ore and its re-deposition on and replacement of the deeper primary (hypogene) sulfides.
In 1957 the Exotica deposit (South Mine) was discovered beneath tailings, which turned out to be the largest known deposit of exotic copper.  This led Anaconda to build an oxide plant, concentrator, smelter, refinery, and town, all next to the mine, plus a power plant in Tocopilla.  However, in 1971, the mine was nationalized and operations were then assumed by CODELCO.
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 Tomić). Despite over 90 years of intensive exploitation it remains one of the largest known copper resources. Its open pit is the world's largest at 4.3 km (2.7 mi) long, 3 km (1.9 mi) wide and over 900 m (3,000 ft) 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 Tomić 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.
Chuquicamata