Name of the Project
Cowal underground development project.

Location
New South Wales, Australia.

Project Owner/s
Evolution Mining.

Project Description
The Cowal Gold Operation (CGO) is an existing opencut gold mine that has been operating since 2005. As per current approvals, CGO will mine an estimated 167-million tonnes of ore over its 28-year life span, processing up to 9.8-million tonnes a year. Gold extraction is undertaken using a conventional carbon-in-leach cyanide leaching circuit.

As at December 31, 2020, the underground project had ore reserves of 1.05-million ounces.

Evolution is seeking approval to build and operate an underground mine at CGO to provide access to another 1.8-million ounces of gold over a 17-year mine life.

The additional gold produced over the estimated life-of-mine of the underground mine will be treated in the same ore processing plant and will rely on the same infrastructure as the openpit mine.

Sublevel open stoping with backfill mining methods will be used.

During the ramp-up phase, the underground mine is expected to produce between 400 000 t and 1.1-million tonnes of ore from 2022 to 2024, increasing to between 1.6-million and 1.9-million tonnes during its peak operation from 2025 to 2031, and winding down to between 0.9-million and 1.25-million tonnes from 2032 to 2038.

Potential Job Creation
Existing jobs at the opencut mine will be retained and it is estimated that about 200 full-time equivalent jobs could be created at the peak of construction.

Once in operation, it is estimated that a further 160 jobs will be created, taking the operational workforce to about 660 full-time jobs.

Evolution has said that, where possible, it will upskill its existing workforce.

Net Present Value/Internal Rate of Return
The project has a pretax internal rate of return of about 15% and a payback of about eight years.

Capital Expenditure
A$380-million will be invested during the 2022 and 2023 financial years, with A$240-million for surface infrastructure, a paste plant, process plant modifications and an accommodation village, and A$140-million for initial mine development costs.

Planned Start/End Date
Not stated.

Latest Developments
Evolution has reported in its financial results for the ended June 30, 2024, that the Cowal underground mine has reached commercial production and has started to contribute to cash flow as it ramps up to its designed capacity. 

Cowal paid back all its acquisition costs and subsequent capital expenditure during the 2024 financial year, generating $294.2-million in net mine cash flow. 

The next phase of the openpit is continuing through the regulatory approval process and remains subject to a final investment decision by the board late in the 2025 financial year.

Key Contracts, Suppliers and Consultants
Perenti subsidiary Barminco (underground mining contract).

Contact Details for Project Information
Evolution Mining, tel +61 2 9696 2900.