29Metals has outlined its restart plan for the rain-battered Capricorn Copper site, with recovery costs forecast to hit as high as $105 million by mid 2024.

A new water treatment plant may add about $37-44 million in capital expense to that total if approved.

Mining activity at the North-West Queensland site remains suspended after an extreme weather event in March left about 500ML in the Esperanza South underground mine.

It also damaged water treatment, workshop and warehouse facilities as well as leaving the operation to deal with elevated water levels across on-site water storage structures.

However 29Metals said there had been no uncontrolled release of mine-affected water from on-site storage and no loss of tailings containment.

29Metals plans to execute a staged approach that would see mining resume at Mammoth/Greenstone in the September quarter of this year and at Esperanza South midway through the first half of next year.

Its planned water management approach includes:

– Scale-up of mechanical evaporation to reduce overall water volumes onsite prior to Phase1 restart (mid-September quarter 2023).

– Continued engagement with regulators on planned water reduction strategies and required approvals.

– Water treatment within on-site water storage structures for release to the environment, subject to regulatory approval.

– Progress initiatives towards targeted negative site water balance for ongoing operations, to be enabled by increased water recycling and reuse.

– Dewatering (and rehabilitation) of Esperanza South via water treatment within on-site water storage structure and eithe rrelease to environment or recycled and reused.

– Additional water diversion infrastructure planned for improved resilience against future extreme rainfall events.

The company today released its revised guidance for 2023 to take into account production lost due to the period of suspension.

It expects Capricorn Copper to mine 514,000 to 584,000 tonnes of ore in 2023 and to mill 473,000 to 543,000, producing up to 9000 tonnes of copper and 50,000 oz of silver.

29Metals has an insurance claims process underway regarding the March weather event and is engaging with lenders, including for a potential refinancing targeted for early 2024.

29Metals describes Capricorn Copper as a large (62Mt in mineral resources estimates1), long-life, high-grade mining operation with potential for mine life extensions.

Major affected areas and planned future controls: