Diversified miner Rio Tinto has approved $498-million of funding for the undergrounddevelopment of an area known as the North Rim Skarn (NRS) at the Kennecott operation near Salt Lake City, in Utah.
Production from the NRS will start next year and is expected to ramp up over two years, delivering about 250 000 t of additional mined copper over the next decade, alongside opencut operations.
In September last year, Rio Tinto approved $55-million to start underground mining in the Lower Commercial Skarn (LCS). Undergroundproduction in LCS started in February and will deliver 30 000 t/y of additional mined copper through the period to 2027.
These two investments will support Kennecott in building an undergroundmine, which will leverage battery electric vehicle technology.
Rio Tinto is also investing $300-million to rebuild the Kennecott smelter – the biggest rebuild in its history.
"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,” commented Rio Tinto Copper COO Clayton Walker.
The miner is studying the next phases of expanding underground production in parallel with work that is being advanced to extend openpit mining at Kennecott beyond 2032. 