SALT LAKE COUNTY, Utah (ABC4) – The Kennecott Copper Mines located deep in Bingham Canyon is set to restart underground mining operations after more than 100 years. 

According to Rio Tinto, the company approved a $55 million investment to start underground mining and expand production at its Kennecott copper operations. The underground mining will initially focus on an area known as the Lower Commercial Skarn, which is expected to deliver 30 tons of “additional high-quality copper” through to 2027 alongside open-cut operations. 

In 2020, operations at the Kennecott facilities were forced to be temporarily halted after a 5.7 magnitude earthquake struck in Magna, causing a hydrochloric acid leak at the refinery. At the time of the incident, Rio Tinto Kennecott said all contractors and personnel were safe and accounted for.

Rio Tinto is expecting the first copper ore from the reopened underground mines to be produced in early 2023, and full production in the second half of the year. The ore will be processed at the existing facilities located at Kennecott. 

“This investment will allow us to quickly bring additional volumes of high quality copper to the market and build our knowledge and capabilities as we evaluate larger scale underground mining at Kennecott,” Rio Tinto Copper chief executive Bold Baatar said in a statement. “We are progressing a range of options for a significant resource that is yet to be developed at Kennecott, which could extend our supply of copper and other critical materials needed for electric vehicles and renewable power technologies.” 

Underground battery electric vehicles are currently being trialed at existing underground mines at Kennecott as Rio Tinto looks to improve employee health and safety in the mines. The vehicles will also increase productivity and reduce carbon emissions from future underground mining fleets. 

A battery electric haul truck and loader supplied by Sandvik Mining and Rock Solutions are being used in the trials to evaluate performance and suitability as part of the underground development work. 

“Trialing underground battery electric vehicles is an exciting step in our work to create a safer workplace for our employees, increase productivity of the mine and reduce emissions from our operations,” continued Baatar. “We look forward to seeing their potential for deployment.”

Currently, the existing underground infrastructure for the mines is being extended to enable early access to the next underground resource and launch feasibility studies to inform decisions on the next phase of underground production. Feasibility studies are also being done to extend open-pit mining past 2032.