Name of the Project
Cowal gold operations (CGO) mine life modification project.

Location
The CGO is located about 38 km north-east of West Wyalong, in New South Wales, Australia.

Client
Evolution Mining.

Project Description
The CGO currently mines the E42 deposit. Evolution has identified additional gold resources within E42 located at depths greater than the currently approved final depth of the existing openpit.

The CGO mine life modification involves continued operations at the existing CGO, within mining licence 1535, for an additional eight years to allow for an additional 1.7-million ounces of gold production.

The modification will not increase the surface area of the existing approved openpit. However, the openpit will be deepened by about 70 m within the deeper primary rock zone. The deepening of the openpit has been designed to maximise ore recovery.

The expansion plans will increase the processing rate at the Cowal plant from 7.5-million tonnes a year to 9.8-million tonnes a year, producing an estimated 6.1-million ounces of gold over the life of the CGO. A secondary ore crushing circuit will be built within the existing process plant.

Operation of the upgraded leach circuit will involve an increase in cyanide consumption and some other reagents process consumables. However, no new reagents process consumables will be used, and no change to the CGO’s existing consumables storage areas, handling or transport methods will be required for the modification.

The existing northern and southern tailings storage facilities (TSFs) will continue to be used to store the additional tailings produced during the life of the modification.

In about Year 16 (2020), construction works will start to allow for using the area between the northern TSF and southern TSF as additional tailings storage.

Construction works will include:
• the construction of connector embankments between the northern TSF and southern TSF;
• the construction of a low-permeability basement layer and other control measures; and
• the extension of the existing northern TSF decant causeway into the new tailings storage area, prior to the point when tailings deposition in the new area overtops the Stage 6 northern TSF embankment.

Following construction of the connector embankments, tailings will be deposited into the central section and the northern TSFs simultaneously.

Potential Job Creation
Cowal currently employs about 400 full-time employees and contractors.

Net Present Value/Internal Rate of Return
Not stated.

Value
Not stated.

Duration
Not stated.

Latest Developments
Evolution Mining has approved the A$25-million to A$30-million capital spend to expand its Cowal processing plant, in New South Wales.

The approval comes about 12 months ahead of schedule, with work planned to start in the March quarter of next year, and commissioning slated for 12 months later.

Evolution has said that between A$15-million and A$20-million in capital would be spent over the 2019 financial year, with a further A$10-million capital spend planned for the 2020 financial year.

The plant expansion is also expected to reduce unit processing costs by between 8% and 12%, or by A$1.25/t to A$1.75/t.

In the next three years, all-in sustaining costs are expected to reduce by about A$5/oz by 2020, and by A$10/oz in 2021.

Further, metallurgical testing of potential future ore sources from the GRE46 and Dalwhinnie mineral systems and the maximum throughput rate achievable from the first phase of the plant expansion need to be assessed before the long-term throughput rate at Cowal can be determined.

Key Contracts and Suppliers
Not stated.

On Budget and on Time?
Not stated.

Contact Details for Project Information
Evolution Mining, tel +61 2 9696 2900 or fax +61 2 9696 2901.