Rio Tinto to develop underground copper mine at Kennecott
Rio Tinto has approved a $108 million investment in underground development to enable early orebody access and undertake orebody characterisation studies for underground mining at the Kennecott copper operations in the US located in Utah near SaltLakeCity.
The mine is also commonly known as BinghamCanyon. The investment builds on $25 million approved in early-2020 to complete a pre-feasibility study to determine the viability of undergroundmining operations at Kennecott.
Potential underground mining would occur concurrently with open pit operations and result in increased copper output. Kennecott holds the potential for a significant and attractive underground development, with declared Mineral Resources of 20 Mt at 3.65% copper and 1.62 g/t gold with further upside potential based on drilling.
The feasibility study work will focus on gathering critical geological, geotechnical and hydrogeological data to inform Rio Tinto’s assessment of underground development options and is expected to be completed in 2024. Existing infrastructure from previous underground projects will be extended to access the NorthRimSkarn orebody, allowing for the development of crosscuts and further drilling of the resource.
The project includes approximately 15,000 ft (4,500 m) of lateral development, 1,000 ft (300 m) of vertical development and associated support infrastructure. The project will also include the trial of underground batteryelectric vehicles to reduce carbon emissions at Kennecott and across Rio Tinto’s global operations.
Sandvik Mining and Rock Solutions will supply a battery electric underground haul truck & LHD to “evaluate performance and suitability for future underground mining fleets.” Pre-feasibility studies are also being progressed to extend open pit mining at Kennecott beyond 2032, with a further push back of the North Wall to allow access to Mineral Resources.
This follows a $1.5 billion investment in the second phase of the South Wall Pushback project, approved in 2019, to allow open cut mining to continue between 2026 and 2032.
