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 approved maximum ore processing rate of up to 7.5-million tonnes a year will not change for the modification. However, the modification will involve upgrades to the existing primary ore-leach circuit to allow for the recovery of gold from flotation tailings and improve gold recovery from the CGO 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:
• construction of connector embankments between the northern TSF and southern TSF;
• construction of a low-permeability basement layer and other control measures; and
• 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.

Jobs to be Created
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
The CGO has been granted regulatory approval from the New South Wales Department of Planning & Environment (DP&E) to extend the operation’s mine life to 2032.

Evolution submitted a modification application, supported by a comprehensive environmental assessment to the DP&E in November 2016.

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.