Mineral Resources and its joint venture partner are investing $490 million in an underground expansion of its Mt Marion lithium operation, a move it expects will pay off in less than a year at current spodumene prices.
The Chris Ellison-led miner and its JV partner, Jiangxi Ganfeng Lithium, made a final investment decision on an expansion of their jointly owned Mt Marion lithium operation, just a week after MinRes greenlit the restart of its wholly owned Bald Hill lithium mine.
MinRes’ investment in its lithium portfolio comes amid a recovery in lithium prices, which have lifted above US$2,000/t after falling to around US$600/t in 2024–25, but remain well below the 2022 peak of US$8,000/t.
It also comes as the company continues preparing to sell an indirect 15 per cent interest in both the Wodgina and Mt Marion lithium mines to South Korean steelmaker POSCO, with the delayed $1.2 billion cash deal now expected to be completed in the first half of FY27.
The joint venture partners in Mt Marion have put a $490 million capital spend price tag on a new flotation plant, underground pre-production development and other infrastructure across the next two financial years.
MinRes plans to operate the Mt Marion open pit mine in combination with an underground operation in a move it says will support the operation’s mine life, aid access to higher-grade product and improve recoveries.
The miner was previously working on an underground exploration decline but those developments were paused in late 2024 as MinRes was tightening its belt in response to weak market conditions at the time.
On Tuesday, MinRes told the market the Mt Marion expansion project payback period would be less than a year at current spot spodumene prices of about US$2,700/t for 6 per cent grade spodumene concentrate.
Mr Ellison told the market on Tuesday the brownfield investment would "set up Mt Marion for decades to come".
“Underground mining and flotation will work together to access deeper high-grade ore, lift recoveries and produce a single 5 per cent product," he said.
“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 Mt Marion call comes a week after MinRes made the decision to return its 100 per cent owned Bald Hill lithium mine to production, a decision also backed by a sustained recovery in lithium prices.
The miner will spend about $20 million restarting the mine, which was mothballed in November 2024 to preserve the mineral resource amid depressed market conditions.
For the Mt Marion expansion, MinRes is currently tendering for an underground mining contractor, ahead of a first quarter of FY27 development start date.
The new floatation plant will be built and operated by MinRes’ mining services division, with construction also expected to commence in the first quarter. Commissioning and ramp-up is tipped for the second half of FY28.
The existing FIFO camp accommodation at the Mt Marion site will also be upgraded from 500 rooms to 750 rooms to support the expansion project.
