Open-cut mining (coal and metals) is used when the minerals are found over a large area and relatively close to the surface. It is a surface mining technique that extracts rock or minerals from the earth by their removal from an open pit or borrow.
Unlike the deepest underground mines, which are mostly concentrated in South Africa, the deepest open pit mines are scattered across the world in some of the most amazing places on the planet.
Here are the five largest open cut mines from around the world:
Mirny, Russia
The Mirny Mine, based in the Sakha Republic, Russia is the second largest man-made pit in the world.
It is so big that it has a no-fly zone around it due to the downdraft it creates!
The mine was built in 1957 and closed in 2011. However, when the mine was operational it was notorious for the extreme conditions where temperatures dropped in winter enough to cause rubber and steel to shatter.
It produced 10 million carats of diamond per annum $$$
Escondida, Chile
Escondida copper mine ranks as the third deepest open-pit operation and is currently the world’s largest copper producing mine. The pit is 3.9km long, 2.7km wide and 645m deep.
Located in the Atacama Desert, Chile the operation consists of two open-pit mines, namely Escondida pit and Escondida Norte pit.
BHP Billiton is the operator of the mine with 57.5% interest. Rio Tinto holds 30% stake in the mine.
It produced 1.1Mt of copper in the financial year ending June 2013, which accounts for about five percent of global copper production. Escondida’s recoverable copper reserve was estimated to be more than 32.6Mt as of December 2012.
Creighton Mine, Canada
Creighton mine is the ninth deepest mine in the world and the world’s deepest nickel mine with a mining depth extending to up 2.42km.
The first production from the open-pit was made in 1901 with underground operations commencing in 1906.
Owned and operated by Vale, current mining methods used include shrinkage mining and mechanised undercut-and-fill mining.
The mine produced 608,000t of ore grading 2.77% copper and 2.55% nickel in 2018.
Exploration drilling carried out at Creighton in 2007 confirmed mineralisation at depth. The Creighton Deep exploration project doubled the proven and probable reserve to 32Mt grading 1.9% to 2.2% nickel and 2% to 2.3% copper.
Fimiston Gold Mine, Australia
Fimiston Gold Mine is Australia’s largest open-pit mine, measuring 3.5km in length, 1.5km in width and 360m in depth.
Also known as the “Super Pit” and “Golden Mine”, it is located 600 kilometres east of Perth on the south-east edge of the Kalgoorlie-boulder
Owned by Kalgoorlie Consolidated Gold Mines, a joint venture between Newmont Mining Corporation and Barrick Gold Corporation, the mine produces 850,000oz annually and has an estimated 8.84 million ounces of proven and probable reserves.
Chuquicamata, Chile
The Chuquicamata (‘Chuqui’) mine is the second deepest open pit mine in the world, at a depth in excess of 850 metres and the largest open-pit copper mine in the world.
Located in the north of Chile, the mine has been operation since 1910, and is now owned by Codelco, a state-owned operation since the Chilean nationalisation of copper mining.
It produces around 11% of the world’s copper supply, which equates to 350,000 tonnes per annum.
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