Mineral Resources (MinRes) and Ganfeng have approved a $490 million expansion at Mt Marion, adding underground mining and a flotation plant to lift lithium recoveries, boost capacity and extend mine life for decades.
MinRes and its joint venture partner Jiangxi Ganfeng Lithium have made a final investment decision (FID) to push ahead with the brownfield expansion at Mt Marion lithium operation in Western Australia.
“This high-return brownfield investment sets up Mt Marion for decades to come,” MinRes managing director Chris Ellison said. “Underground mining and flotation will work together to access deeper high-grade ore, lift recoveries and produce a single 5 per cent product.”
“I thank our partner Ganfeng for their collaboration on the design and commitment to these projects, which will ensure we unlock the full potential of Mt Marion.”
The investment will be spread across the 2026-27 financial year (FY27) and FY28 and includes $240 million for a flotation plant, $220 million for underground pre-production development and $30 million for non-processing infrastructure.
MinRes said the project’s payback period at the current spot price of about $US2700 per tonne spodumene concentrate 6 per cent (SC6) was expected to be less than one year.
The expansion is designed to access additional mineral resources below the existing open pit while improving plant recoveries towards 70 per cent.
Installed capacity is expected to rise from around 500,000 tonnes per annum of SC6 to 600,000 tonnes per annum, while the operation will transition to a single SC5 product by removing lower-grade SC3.5 output.
Tendering for an underground mining contractor is underway, with central underground development expected to begin in the first quarter of FY27. From FY28, Mt Marion will operate as a combined open pit and underground mine, with underground ore expected to contribute up to 40 per cent of processing feed.
The flotation circuit will recover fine spodumene currently lost to tailings and will be constructed and operated by MinRes’ Mining Services division. Construction is targeted to begin in the first quarter of FY27, with commissioning and ramp-up expected in the second half of FY28.