Summary:Macmahon secures a $247m underground mining contract for Mt Marion lithium project, supporting the site’s open-pit to underground transition and long-term lithium supply expansion....

Macmahon Holdings, one of Australia’s premier mining contract service providers, has officially secured a landmark $247m Mt Marion lithium project contract to deliver full underground mining operations at Western Australia’s flagship lithium asset. Awarded by Mineral Resources (MinRes) and joint venture partner Jiangxi Ganfeng Lithium, the three-year mining services agreement includes an optional one-year extension, covering comprehensive underground development, stope production and site operational management. This pivotal contract signals a critical strategic transformation for Mt Marion, shifting the project from mature open-pit mining to long-life underground lithium mineralisation extraction. As one of Australia’s highest-grade hard rock lithium mines, the transition underpins sustained global lithium feedstock supply for battery manufacturing and energy transition industries worldwide.

Core Contract & Project Operational Metrics

The new Macmahon contract forms a core component of Mt Marion’s $490 million expansion program, designed to extend the mine’s operational lifespan and unlock high-grade underground lithium ore reserves. Previously focused exclusively on open-pit mining, the project’s underground expansion will stabilise long-term production capacity amid depleting surface mineral resources.

[Table Placeholder: Table 1 – Macmahon $247m Mt Marion lithium underground mining contract core specifications]

Strategic Significance of Mt Marion Underground Transition

The award of the Mt Marion underground mining contract to Macmahon addresses two key challenges facing Australia’s mid-tier lithium supply chain: depleting open-pit reserves and volatile global lithium pricing. After over a decade of continuous open-pit spodumene production, surface ore bodies at Mt Marion are nearing maturity, requiring underground expansion to maintain consistent output levels.

Macmahon’s specialised underground mining expertise brings robust geotechnical management, mechanised mining workflows and strict safety compliance frameworks tailored to hard rock lithium pegmatite deposits. This professional contracting model will optimise mining recovery rates, reduce operational costs and ensure stable ore feed to the site’s existing processing and flotation circuits. The expansion also supports the newly constructed on-site flotation plant, enabling full-process spodumene concentrate production for global battery material manufacturers.

Market & Supply Chain Impact

As one of the world’s most influential producing lithium mines, the long-life extension of Mt Marion delivers critical stability to global lithium markets. Following widespread lithium price volatility in recent years, sustained production from Australia’s high-grade hard rock lithium assets remains central to global EV and energy storage supply chain security.

For MinRes and Ganfeng Lithium, the partnership with Macmahon de-risks the capital-intensive underground expansion project, leveraging professional mining contractor efficiency to accelerate project commissioning. For Macmahon, the $247m deal strengthens its leading market position in Western Australia’s critical minerals underground mining sector, expanding its lithium-focused service portfolio beyond traditional iron ore and gold contracting businesses.

Industry analysts note the Mt Marion underground transition sets a benchmark for Australian lithium mines, proving a viable pathway to extend mine life and secure long-term spodumene supply amid tightening global critical mineral demand.

 Figure 2 – Macmahon underground mining equipment deployed for Mt Marion lithium expansion]

Conclusion

Macmahon’s new $247m Mt Marion lithium project contract marks a transformative milestone for Western Australia’s critical minerals sector, driving the permanent shift of Mt Marion from open-pit to underground lithium production. Backed by a three-year enforceable service agreement and broader $490m site expansion strategy, the partnership guarantees sustained high-grade spodumene output, extends mine operational life, and stabilises global lithium supply chains. Moving forward, the progressive ramp-up of underground mining activities will be closely monitored by lithium traders, battery manufacturers and mining investors, positioning Mt Marion to retain its status as a cornerstone asset of the global energy transition mineral supply network.