After our overnight bus to Calama, one of the driest cities in the world, Colin and I managed to find a hostel in the early hours of the morning. We had decided to return to Calama, and city we previously passed through on the way to San Pedro earlier in the month. Our reason for revisiting was to pay a visit to Chuquicamata, the biggest open pit copper mine in the world. Due to the numerous earthquakes, the national mining company Coldeco had stopped running tours temporarily – but our persistence meant we were able to get on one of the first tours once they re-opened to the public.
We had our first day in Calama to relax, as there really wasn’t a single thing to do besides the copper mine tour. The following afternoon we caught a collective taxi to the administration center for the mine and met our group. The Coldeco employees handed out safety vests and hardhats, then ushered us onto a large tour bus. Our first stop was at a former mining village called Chuquicamata, situated just outside of the mine itself. This village was one in the region which was self-sustaining, containing houses, schools, shops, and work for local people. Copper was big business after the collapse of Chile’s saltpeter industry which we witnessed in Iquique. The copper mined in Chile accounts currently for 1/3rd of all the copper exports in the world. At its’ peak, copper from Chile made up 3/4ths of the copper exports in the world. 30% of the copper from this Chilean mine’s production is purchased by China and 40% by Asia in general, due to its 99% copper purity which is necessary for use in medical and technological devices.
However, since the decline of the ‘Red Gold Fever’ this copper mine has been steadily depleted, to the point where the mine is currently in the process of transitioning (within the next 4 years) from an open-pit mine to an underground mine in order to access the copper deep inside. Just 1 more kilometer can lead to 50 more years of production. Fortunately the underground mine (which would be operated by conveyer belt) will be safer, as well as eliminate 90% of the current pollution. The underground mine will also be cheaper due to the high cost of the large amount of fuel (they can hold 5,000 liters of fuel each) the $5 million USD machines require as they burn 3 liters of fuel per minute of operation… that is 2 years worth of a normal car’s fuel used in just one day! The trucks themselves are also very expensive, each tire costing $40,000 USD and lasts only 8 months. Even the truck drivers are costly, making $7000 USD per month for their efforts!
Due to safety concerns, the people from this village were moved in 2005 to Calama – and we could see why. The whole town and its houses seemed to be covered in a layer of dust from the copper mine nearby. The history of copper in the region started way before Chuquicamata however. Ancient miners have been found trapped in mine shafts supposedly dating from 550 AD.
After seeing the town, Colin and I were driven to the mine itself. At the viewing platform we peered down into the massive crater-like pit below. From where we were standing the huge trucks looked like little toys. The information panels nearby told us some statistics on what we were looking at. With a length of 4.3 kilometers and a depth of 900 meters, the mine in Calama is the second deepest in the world after one in Utah. Chuquicamata mine began in the early 1900’s when an American engineer who could treat low grade copper and a group of industrialists (including he Guggenheim brothers) got together and bought the property containing the copper in the area. They constructed Chuquicamata mine which reached production of 135,000 tons by 1929. Currently the mine produces more than 30 million tons of copper and is worked on by more than 14,000 employees. While the copper is deep inside the center of the mine, the whole mine is dig out in ‘benches’ in order to keep its stability. As the trucks work the mine they move slow and steady, taking nearly an hour to get down to the floor of the mine.
Finished looking at the open-pit, the group moved on. While we weren’t allowed to tour inside the processing buildings, we did get to hear from our guide all about the process and we drove around. I also took some photos of images the mine provided to us so we could follow how they processed the copper.
First huge machines such as the ones above are used to extract the minerals from the rock bed. The “waste rock material” (400,000 tons for every 1,000 tons of pure copper) is piled up in hills around the copper pit. The rock is then transported with massive trucks to be crushed, mixed with water, and then treated with oxygen. This treatment process causes the copper metal to rise to the top and gather together.
Next the mixture goes through a smelting process where it is heated to 1200 degrees and combined with a chemical reducing agent in order to remove the oxygen. As a result a melted copper mixture is created which is then made into solid metal sheets. The final step is electro-refining. During this process electricity is applied to the copper sheets in order to create 99.9% copper purity. Each expensive sheet is worth $1000 USD. After this each 170 kilogram pure copper sheet is bound together and placed on a train (4 trains per day) which, by 14 days later, arrives to the port of Mejillones 280 kilometers away for export. We had good timing and got to see the train heading out to the port loaded with these heavy copper sheets.
While the tour didn’t last very long it was worth it to see a glimpse into one of Chile’s biggest industries. Seeing the copper mine and the amount of resources and electricity running it requires provided us with a great contrast to the anti-dam movement in the South of Chile and allowed us to see the full struggle between environment and the needs and desires of humans.
Francesca
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