Anglo-Australian mining company Rio Tinto is planning to invest $920m at its Kennecott operation in Utah, US, to strengthen its copper supply.

Of the total approved investment, the company will allocate $498m to develop an underground mine and infrastructure in an area known as the North Rim Skarn (NRS).

Rio Tinto expects the NRS to deliver around 250,000 tonnes of additional copper over the next ten years besides open-cut operations. It is scheduled to start production in 2024.

Rio Tinto Copper chief operating officer Clayton Walker said: “We are investing to build a world-class underground mine at Kennecott and strengthen our processing facilities, to meet the growing demand for copper in the United States, a key material for domestic manufacturing and the energy transition.

“This investment will position Kennecott to continue the strong contribution it has made as part of the Salt Lake Valley community for 120 years, injecting about $1.5bn annually to the local Utah economy.”

The company plans to assign $300m to rebuild the smelter, including a furnace.

A future $120m investment will be made to upgrade the refinery tank house structure at the Kennecott mine and update its molybdenum flotation circuit with a fully automated system.

Rio Tinto said it is advancing work to extend the open-pit mining at the Kennecott mine beyond 2032.

In 2022, the company approved a $55m investment to start underground mining at Kennecott mine.