Codelco denied media reports that the company expects production at its Chuquicamata copper mine in Chile to drop 40% over two years because of a US$4.88 billion project to convert the open-cast mine into an underground operation, Mining.com reported May 24, citing a company statement.

The Chilean state miner said that it would maintain global production levels at about 1.7 million tonnes of copper for at least the next 10 years.

According to a May 23 Reuters report, copper output at Chuquicamata was expected to drop to 182,000 tonnes by 2021, from 459,000 tonnes this year, as Codelco decreased and eventually stopped open-pit operations in 2020.

The reduction was expected to result in a 4% decline in the miner's global copper output in 2021 to 1.66 Mt, compared to the 1.73 Mt estimated for the current year. The report added that Codelco was going to take until 2027 before production exceeded this year's levels.

The switch to underground mining, part of the company's 10-year, US$40 billion plan to overhaul its aging copper operations, is expected to extend life of the Chuquicamata mine by about 50 years.

Following the switch to underground mining, Chuquicamata is estimated to produce 320,000 tonnes of copper and 15,000 tonnes of molybdenum.

Codelco kicked off underground mining at Chuquicamata ahead of schedule, with over 8,000 tonnes of ore extracted since early April.