Mineral Resources Limited (ASX: MIN) today announced that MinRes and its joint venture partner Jiangxi Ganfeng Lithium Co Ltd (Ganfeng) have decided to make a Final Investment Decision at the Mt Marion lithium operation to construct a flotation plant along with underground mining.
Figure 1: Mt Marion lithium operation site in Western Australia [Courtesy: Mineral Resources]
The estimated amount of investment is around A$490 million on a 100% basis. This project is invested across FY27 and FY28. This investment is important as it can give a strategic advantage to both Companies. It is estimated to increase the capacity from approximately 500ktpa SC6 to 600ktpa SC6.
Inside the Mt Marion Expansion Plan
Flotation Plant
When lithium is processed, not all of it gets captured the first time. Some fine particles slip through and end up in what miners call tailings, essentially waste. A flotation circuit goes back and recovers that fine spodumene before it is lost for good.
At Mt Marion, that is exactly what is changing. MinRes will add a flotation circuit alongside the existing dense media separation plant. The Company’s own Mining Services division will build and run it. Construction is set to begin in Q1 FY27, with commissioning and ramp-up expected in the second half of FY28. And when it is up and running, plant recovery at Mt Marion is expected to improve towards 70%.
Underground Mining Development
Mt Marion has operated as an open-pit mine. That means ore has been extracted from the surface downward, which works well until going deeper no longer makes sense for open-pit methods. Underground mining solves that. It goes further down and reaches ore that open-pit simply cannot access.
MinRes and Ganfeng have already begun tendering for an underground mining contractor. Central underground development is expected to commence in Q1 FY27. From FY28 onwards, Mt Marion will run as a combined open-pit and underground operation.
Underground ore from open stoping is expected to supplement up to 40% of the total processing feed. That is not a small number. It extends the life of the mine and gives the Mt Marion expansion access to deeper, high-grade ore that would otherwise stay in the ground.
What the Combined Operation Delivers
The Mt Marion mine expansion news 2026 is not just about spending A$490 million. It is about what they spend on the ground, actually. Together, the flotation plant and underground mining are set to deliver four key operational changes at Mt Marion:
- Support mine life by providing access to additional mineral resources below the existing open pit
- Improve plant recovery towards 70%
- Increase installed capacity from approximately 500ktpa SC6 to 600ktpa SC6
- Remove the lower-grade SC3.5 product to deliver a single SC5 product
That last point matters more than it might look at first glance. A single, cleaner product is easier to sell, easier to price, and far less complicated to manage across the supply chain.
Chris Ellison on the Mt Marion Lithium Expansion Decision
MinRes Managing Director Chris Ellison described the investment as a high-return brownfield decision that positions Mt Marion strongly for the decades ahead.
He said the underground mining and flotation components are designed to work together, accessing deeper high-grade ore, lifting recoveries, and producing a single 5% product.
Figure 2: MinRes Managing Director Chris Ellison [Courtesy: Mineral Resources]
Ellison credited Ganfeng for their collaboration on the design and their commitment to both projects, noting the partnership would help realise the full potential of Mt Marion.
MinRes Share Price
Here is a quick snapshot of Mineral Resources Limited (ASX: MIN) is currently trading:
- Last share price: A$71.330 per share
- Market capitalisation: A$14.13 billion
- 52-week range: A$18.460 to A$72.940 per share
Figure 3: Mineral Resources Limited (ASX: MIN) share price chart [Courtesy: ASX]
Industry Outlook
Australia accounts for 41.3% of global lithium supply, with the largest single source globally. And that output is primarily from hard-rock mining, the process used at Mt Marion which comprises 66% of the total world lithium supply. That context is the important factor when you need to justify a A$490 million Mt Marion expansion decision.
Figure 4: Global lithium demand growth outlook through 2034 [Courtesy: Metals Hub]
The demand picture is getting bigger and badder. According to data from Lithium Harvest, global lithium consumption could be 6.5x higher than 2023 volumes based on forecast demand in 2034. A major part of that story is battery storage.
Figure 5: Global lithium production share by extraction method and region [Courtesy: Metals Hub]
Grid-scale additions crossed 90 GWh in 2024, and Bloomberg NEF sees installations compounding at over 30% annually through the second half of the decade.
Governments are not slowing that down either. The EU, the United States, and China all have active policy frameworks pushing EV and battery manufacturing forward. For ASX lithium stocks, that kind of long-term policy visibility is as important as the spot price on any given day.
Supply, however, is not keeping up cleanly. Several producers have pulled back on project development or reduced refining capacity in response to recent price softness.
Forecasts from RMIS and CarbonCredits point to a potential structural deficit by 2029 if meaningful new capacity does not come online in time. That is the market the Mt Marion lithium expansion update is stepping into.
Future Direction and Impact on Mt Marion Mine Output
As construction and commissioning are going to be carried out, minimal disruption is expected to current operations. At the site, the accommodation camp will be expanded from 500 to 750 rooms to accommodate the workforce needed for both projects.
By FY28, you can get the complete picture. This will include the existing plant in Mt Marion, which is now a hybrid open-pit and underground mine, also using a flotation circuit. The ASX lithium stocks impact here is simple: more capacity, a cleaner product and a longer mine life at one of Australia’s most established lithium operations. The Mt Marion expansion is not just a change to the operation.
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Frequently Asked Questions
Q1. What did MinRes and Ganfeng decide?
Ans. They agreed to build a flotation plant and develop underground mining at Mt Marion, committing A$490 million on a 100% basis.
Q2. When does construction start?
Ans. Both projects are targeted to commence in Q1 FY27, with full operations expected from FY28.
Q3. What changes for Mt Marion after the expansion?
Ans. Capacity increases and the operation moves to a single, cleaner SC5 product.
Q4. What is the estimated payback period of the Project
Ans. The payback period is estimated at less than one year.
Disclaimer
This article is meant only for informational purposes. If you are an investor who is watching Mineral Resources Limited closely, all the data published in the content is sourced from ASX announcements and external sources. Kindly verify all information related to the share price and market data. Any investment should be made at the investor’s own risk. Colitco does not hold any position in the above-mentioned Company.
Sources
https://www.metals-hub.com/en/blog/whats-driving-lithium-demand-in-2025-and-beyond/
https://www.mineralresources.com.au
https://www.asx.com.au/markets/company/MIN
Tags: Ganfeng, Mineral Resources Limited, Mt Marion, Mt Marion lithium operation Last modified: May 26, 2026
