Rio Tinto completes conversion of Kennecott heavy mining fleet to renewable diesel use - International Mining

Rio Tinto has completed the transition from conventional to renewable diesel for all heavy mining equipment at its Kennecott copper mine in Utah, giving the mine one of the lowest carbon footprints of any copper producer in the US, it claims.

Kennecott’s fleet of 97 haul trucks and heavy machinery equipment at the mine, concentrator, smelter, refinery and tailings are now all fuelled by renewable diesel (a combination of 90% soybean and the remainder animal fat and used cooking oil) sourced in the United States. This is expected to reduce the mine’s Scope 1 emissions by 450,000 t, equal to eliminating the annual emissions of 107,000 cars. In addition, the switch to renewable diesel reduces PM2.5 (particulate matter less than 2.5 microns) emissions at the tailpipes of its haul truck fleet by 40%, a reduction equivalent to approximately 2,300 million miles of light vehicle travel annually.

“Kennecott has one of the lowest carbon footprints of any copper producer in the United States, thanks to recent initiatives such as the closure of a coal-fired power plant, installation of a 5 MW solar farm, deployment of battery-electric vehicles underground, and the transition to renewable diesel,” the company says. “The operation’s overall carbon footprint has now been reduced by more than 80% from 2018 levels.”

Speaking at an event on site with the Governor of Utah, Spencer J Cox, to celebrate the achievement, Rio Tinto Copper Chief Operating Officer, Clayton Walker, said: “The transition to renewable diesel is a significant step toward our decarbonisation goals at Kennecott where we have now reduced emissions by 80%, thanks to a range of initiatives in recent years. We remain committed to being responsible stewards of the environment and are always looking to find better ways to provide the materials the world needs for the energy transition.”

Kennecott’s transition to renewable fuel will also make low-carbon fuel more accessible in the state of Utah. In partnership with Kennecott, HF Sinclair is dedicating two tanks to renewable diesel for the mine with each having tank capacity of 18,000 barrels or 756,000 gallons.

HF Sinclair Executive Vice President, Commercial, Steven Ledbetter, said: “We’re proud to support Rio Tinto’s sustainability journey with a low-carbon fuel produced at our facilities. We’re excited to see Kennecott move from trial to full implementation and what this could mean for other industries with evolving energy needs.”

In 2023, Kennecott conducted an initial trial of renewable diesel, which compared two trucks using regular diesel against two using renewable diesel. Officials measured the trucks’ acceleration, cycle time, fuel usage and engine inspection reports. The renewable diesel was trialled successfully, complementing similar test findings from Rio Tinto’s Boron mine in California.

Combined with Rio Tinto’s Boron mine – which completed the full transition of its heavy machinery from fossil diesel to renewable diesel in May 2023 – renewable diesel use at Kennecott replaces 11% of Rio Tinto’s global fossil diesel consumption with renewable diesel.

Rio Tinto is targeting reductions in Scope 1 and 2 emissions of 50% by 2030 and net zero by 2050.