RANKED: World’s 10 biggest underground mines by tonnes of ore milled

RANKED: World’s 10 biggest underground mines by tonnes of ore milled

Ore is every miner’s paydirt, and the more ore – a natural aggregation of one or more minerals that can be mined, processed, and sold at a profit – the bigger the paycheque.

The number of tonnes extracted from the earth in a day can be vast at the world’s largest mines, and the ore that contains sufficient valuable mineral to be treated by milling process is what ends up going into the processing plant compared to run of mine ore production.

Using data compiled by our sister company Miningintelligence, our latest top ten list ranks the world’s biggest underground mines by tonnes of ore milled.

#1 Grasberg

Mining method: block caving. Geology: porphyry, skarn

In first place is the iconic Grasberg copper-silver-gold mine in Indonesia, a joint venture between Inalum (51.24%) and Freeport-McMoRan (48.76%). Based on the figures provided to the end of Q-3 2021, 51.53mt of milled ore is forecasted for the year. Grasberg is moving to an entirely underground operation – nearly doubling copper and gold output in the process.

#2 Cadia Valley

Mining method: block caving. Geology: porphyry, skarn

In second place is Newcrest’s Cadia Valley mine in Australia, where 28.8 million tonnes (mt) of copper, silver and gold milled ore is projected for the year, based on data available through to the end of Q3 2021. Newcrest expects to begin the early works program for an expansion which includes the development of the P2-C3 block cave by the end of the year. First production for this is forecasted for 2026.

#3 Olympic Dam

Mining method: sublevel stoping. Geology: Iron oxide, copper, gold

Third place goes to BHP’s Olympic Dam mine, also in Australia. Based on ore milled to the end of Q3, total estimated for the year is 8.92mt of copper, gold, silver and uranium ore. Last year, the world’s biggest miner shelved a planned $2.5 billion expansion after studies of the ore body revealed weaker than anticipated results.

#4 Padcal

Mining method: block caving. Geology: porphyry

Coming in fourth is Philex Mining’s Padcal mine in the Philippines. Based on annualized production figures, 7.96mt of copper, silver and gold ore is expected for 2021. In 2018, Padcal alone accounted for 9% of gold output in the country. The mine has been in operations since 1958 but is expected to close in 2022.

#5 Kroondal

Mining method: room and pillar. Geology: magmatic sulphide

The number five spot goes to Anglo American Platinum and Sibanye Stillwater’s jointly owned Kroondal mine in South Africa. Based on annualized figures, estimated for the year is 7.2mt of copper, silver and PGM ore milled.

#6 Cerra Lindo

Mining method: sublevel stoping. Geology: volcanic hosted massive sulphide

In sixth place is Nexa Resources’ Cerra Lindo mine in Peru. Based on the data, estimated for the year is 6.40mt of milled copper, silver, gold lead and zinc. Folllowing a dispute with Chavín y Valle de Topará farming communities in Peru’s western department of Ica, Nexa reached a deal last year related to the benefits people are expecting to receive for allowing the Cerro Lindo operation near their respective towns.

#7 Amandelbult

Mining method: breast stoping. Geology: magmatic sulphide

Anglo American Platinum’s Amandelbult in South Africa is in seventh place, with 5.72mt of platinum group metals, copper, nickel and silver milled ore expected for the year.

#8 New Afton

Mining method: block caving. Geology: porphyry

In eighth place, New Gold’s New Afton mine in British Columbia, Canada is expected to mill 4.91mt of copper, silver and gold ore this year. New Gold was also granted its mining permit for the B3 zone of New Afton this year.

#9 Carapateena

Mining method: sublevel caving. Geology: iron oxide, copper, gold

Oz Minerals’ Carapateena mine is in ninth place, where 4.48mt of copper, silver and gold milled ore is expected for the year. The Carapateena discovery that Teck saw as its big foreign play until the financial crisis was acquired by OZ Minerals in 2011.

#10 Udachny

Mining method: sublevel caving. Geology: kimberlite

The only diamond mine to make the list rounds it out — Alrosa’s Udachny mine in Russia, based on figures to end Q3, is projected to mill 3.39mt of ore this year. This year, Alrosa also announced plans to convert an additional 166 vehicles in Udachny and Lensk to natural gas in a move to cut emissions.

Honorable mentions for 2021 go to Boliden’s Garpenberg copper-silver-gold-lead-zinc mine in Sweden, where, based on the figures provided to the end of Q-3 2021, 3.07mt of milled ore is forecasted for the year, and Barrick Gold’s Jabal Sayid mine in Saudia Arabia, which is expected to produce 2.16mt of milled ore.