Rio Tinto, the London-based global mining giant that owns the Kennecott copper operations in Salt Lake County, has announced an additional $498 million investment in its Utah mine.
In an effort to strengthen its supply of copper in the United States by increasing production from underground mining, the investment will go to funding underground development and infrastructure for an area known as the North Rim Skarn (NRS) in the Magna mine. Production from the NRS will commence in 2024 and is expected to ramp up over two years, eventually delivering around 250,000 tons of additional mined copper over the next 10 years. The NRS is an underground mining effort alongside Kennecott’s ongoing open pit operations.
In September 2022, Rio Tinto approved development capital totaling $55 million to start underground mining in an area known as the Lower Commercial Skarn (LCS). Underground production within LCS started in February and is expected to deliver a total of around 30,000 tons of additional mined copper through 2027.
When it announced the LCS mine opening, Rio Tinto said the operation will leverage battery electric vehicle (BEV) technology, following a successful trial in 2022. BEVs create a safer and healthier workplace for employees underground, increase the productivity of the mine and reduce emissions from operations, the company said. The new NRS mine will also use BEV technology.
A $300 million rebuild is also underway at the Kennecott smelter near Tooele. The rebuild is the largest in Kennecott’s history and began in May. A further $120 million is being invested to upgrade the refinery tank house structure and update Kennecott’s molybdenum flotation circuit with a state-of-the art, fully automated system. As the second- largest copper producer in the U.S., Rio Tinto said the nearly $1 billion in improvements in Utah will allow Kennecott to continue to deliver a high-quality product to customers.
“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,” said Clayton Walker, Rio Tinto Copper chief operating officer. “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 $1.5 billion annually to the local Utah economy.”
Walker said studies are ongoing to help decisions on the next phases of expanding underground production.