64Mt Capricorn Copper Project Moves Toward Restart as New Tailings Facility Becomes Critical Next Step

Capricorn Copper restart planning has reached a critical infrastructure point: water is no longer the main obstacle — approval of a new long-term tailings storage facility is.

29Metals is progressing plans to recommission its high-grade copper-silver operation in North West Queensland, supported by approximately 64 million tonnes of Mineral Resources and a 19.2 million tonne Ore Reserve.

At the latest Diggers & Dealers Mining Forum, chief executive James Palmer said the new tailings storage facility has become the critical requirement for a production restart now that site water inventories have been substantially reduced.

For contractors, the restart pathway now has a clear infrastructure focus: a large underground copper operation, existing processing infrastructure and one major environmental and civil asset sitting directly on the restart pathway.

Capricorn Copper restart has shifted from water management to infrastructure approval

Capricorn Copper has spent several years working through the consequences of severe weather in North West Queensland.

The major 2023 rainfall event caused substantial water-related disruption, while operations were later suspended again in March 2024 following further rainfall and accumulation within regulated water-storage structures.

The position has now changed materially.

29Metals reported in July that total site water inventory had fallen substantially below the maximum operating level and that water was no longer an impediment to a future production restart.

The Capricorn Copper restart has therefore moved onto its next critical issue: obtaining regulatory approval for long-term tailings capacity.

Tailings Infrastructure

TSF3 creates a major civil and water-management interface

Tailings infrastructure is not simply a storage pond.

Projects of this type can involve substantial embankment earthworks, engineered fill, drainage, decant systems, pipelines, pumping, erosion protection, instrumentation and environmental controls.

That makes TSF3 particularly relevant to civil, earthworks, water and mining-infrastructure contractors if and when construction packages progress.

TSF3 is designed to provide Capricorn Copper with long-term tailings capacity

The proposed Tailings Storage Facility 3 is intended to address a fundamental constraint at the existing operation.

Industry reporting based on the project’s approval documentation says Capricorn Copper’s two existing tailings facilities have reached their storage capacity.

The proposed TSF3 would be developed between the Esperanza Waste Rock Dump and Upper Esperanza Diversion Dam, incorporating raising and reprofiling of existing mine infrastructure.

The current design has an expected storage life of approximately 6.5 to 7.5 years, although the actual life will depend on operating conditions and final design outcomes.

It would receive metalliferous tailings as well as material associated with water-treatment processes and would form part of the infrastructure required to support a sustainable mine restart.

The restart pathway now has five clear milestones

Unlike a project with a fixed construction commencement date, Capricorn Copper remains dependent on several linked decisions.

The restart can therefore be followed through its critical-path milestones.

29Metals says it is considering non-dilutive funding options as it coordinates the restart DFS and financing work.

This sequencing means there is currently no reliable fixed production-restart date.

Instead, the approval of TSF3 and completion of the DFS are the two most important near-term milestones.

64Mt of resources gives Capricorn Copper substantial restart leverage

The scale of the underlying resource is one reason 29Metals continues to pursue the asset despite the operational interruption.

Management describes Capricorn Copper as containing approximately 64 million tonnes of Mineral Resources at around 1.8% copper, representing approximately 1.2 million tonnes of contained copper.

The operation also carries approximately 19.2 million tonnes of Ore Reserves.

Before the extreme 2023 weather event, the mine was operating at an annualised production rate of approximately 24,000 tonnes of copper metal.

At the 2026 Diggers & Dealers conference, 29Metals outlined restart potential of up to approximately 30,000 tonnes per year at full capacity.

Management says this could more than double the company’s annual copper production when combined with Golden Grove.

Existing processing infrastructure strengthens the brownfield restart case

Capricorn Copper is not a greenfield deposit waiting for an entirely new mine and processing facility to be built.

It is an established underground copper operation with surface infrastructure, processing facilities and existing underground development.

That is why 29Metals describes the project as a comparatively low-capital-intensity brownfield pathway back into production.

Management has also indicated it is examining opportunities to expand processing capacity as part of the mine’s future growth pathway.

No specific new processing capacity or approved expansion scope should yet be assumed from those comments.

Process Plant

Recommissioning can generate a major fixed-plant workstream

Bringing an established mineral-processing plant back into reliable production can require extensive inspection, refurbishment, repairs, replacement and recommissioning.

Likely interfaces can extend through mills, conveyors, pumps, piping, structures, electrical systems, instrumentation, controls, access systems and supporting utilities.

Contractor exposure could span tailings, processing, underground and water infrastructure

The contractor significance extends beyond the proposed restart itself.

It is that several different infrastructure systems may need to align before a sustainable restart can occur.

TSF3 provides the immediate critical-path project, while the wider restart can potentially create work around the processing plant, underground mine, water systems and existing surface infrastructure.

Integrated Mine Infrastructure

Restart depends on more than the underground mine

Capricorn Copper’s restart case combines underground production, surface processing, water management and long-term tailings infrastructure.

That integration is exactly why the project has relevance across a broad North West Queensland contractor and supplier base.

Capricorn Copper adds another project to the North West Queensland copper pipeline

Capricorn Copper is located approximately 120 to 125 kilometres north of Mount Isa in the Western Fold Belt of the Mount Isa Inlier.

The wider 29Metals exploration position covers approximately 1,900 square kilometres in a region already known for copper, lead, zinc and silver mineralisation.

That places the restart within a broader North West Queensland investment pipeline increasingly centred on copper and critical minerals.

Related regional investment includes the $600 million Mount Isa copper industry support program , which focuses on the future of regional smelting and refining capability.

The wider Queensland copper and critical-minerals development pipeline spans Mount Isa, Cloncurry, Julia Creek and surrounding resource areas.

Capricorn provides another piece of that regional picture: an existing copper operation where infrastructure approvals and brownfield recommissioning could unlock meaningful production without developing an entirely new mine from scratch.

Mine restart stories increasingly depend on supporting infrastructure

The Capricorn case highlights an important issue for mining contractors.

Production is not determined by the orebody alone.

A mine can have significant resources, existing underground development and an established processing plant, yet still depend on supporting infrastructure before operations can resume.

At Capricorn Copper, water management dominated the recovery process for several years.

Now that water inventory has been reduced, tailings capacity has moved to the front of the restart sequence.

The next commercial workstream may therefore emerge not from mine development itself, but from the enabling infrastructure required around it.