Mid-west US Caterpillar equipment dealer Empire Southwest has entered into a master service agreement to supply mining gear and services to ioneer at its proposed US$1.7 billion Rhyolite Ridge lithium-boron project in Nevada, which plans to be the first mine to run an autonomous haulage fleet with Caterpillar mid-size trucks.
ASX and Nasdaq-listed ioneer’s 2025 project technical report outlined $440 million of machinery and equipment and circa-$39 million of control system costs for Rhyolite Ridge in a revised capital expenditure total that was double its 2020 feasibility study estimate.
The mobile fleet budget covers 16 Caterpillar 785 (nominal 139-tonne-payload) trucks plus a range of loading and ancillary equipment from the manufacturer.
ioneer has a US$996 million US Department of Energy loan as part of its project funding package.
“The use of autonomous haulage in mining and quarry operations is relatively new but has proven to be both reliable, safe and cost effective in the long term,” ioneer said in last year’s technical report, though it added that, “a limited amount of information regarding cost advantages and operational performance gains for autonomous haulage is available from original equipment manufacturers and vendors due to the proprietary nature of this information”.
“ioneer has partnered with Caterpillar to develop the 785 model haul truck as an autonomous haulage vehicle … and the Rhyolite Ridge project will be the first property to deploy these trucks in an autonomous form.”
The developer and manufacturer signed an MoU back in 2021 on autonomous equipment for Rhyolite Ridge. Caterpillar said it had built the credentials of its autonomous mine trucks on deployments of high-capacity vehicles in places such as Western Australia’s Pilbara region. “We are now seeing … economic viability for autonomy at smaller mines with [smaller] fleets,” it said.
The deal with Empire covers services, technology and equipment rental.
Rhyolite Ridge is pegged as the largest undeveloped lithium-boron ore reserve in the world outside Turkey and could support an operation producing 3.2 million tonnes per annum of plant feed for more than 80 years.
“Rhyolite Ridge is a multi-generational deposit and we anticipate this being a multi-generational partnership,” ioneer senior vice president of engineering and operations, Matt Weaver, said.
