Name of the Mine
Cowal Gold Operation.

Location
The Cowal mine is located about 350 km west of Sydney and 40 km north-east of West Wyalong in New South Wales, Australia, on the traditional lands of the Wiradjuri people.

Mine Owner/s
Evolution Mining.

Brief Description
Cowal is a large-scale, low-cost gold producer with a long mine life. The operation includes openpit and underground mining, supported by a comprehensive processing plant.

Cowal currently has two mining leases – ML1535 and ML1791 – covering about 29 km2. Surrounding the mining leases, Evolution holds highly prospective exploration tenure over a further 1 390 km².

Brief History
Gold was first discovered in the West Wyalong area in 1893. Extensive exploration at Lake Cowal was undertaken by North Limited in the 1980s and 1990s. 

Development consent conditions for the Cowal gold project were issued by the New South Wales government in 1999. The Cowal gold project was sold to Homestake Mining in 2001, which subsequently merged with Barrick Gold Corporation in 2002. Construction started in 2004, and the first gold was poured in April 2006. 

Evolution Mining acquired the Cowal mine in 2015. The mine life has been extended several times, with regulatory approval for plant expansion in 2018 and underground mine approval in 2021. Underground production started in 2023, and commercial production in April 2024. New South Wales regulatory approval to extend openpit mining operations by ten years and overall operations to 2042 was received in December 2024.

Primary Metals/Minerals 
Gold.

Secondary Metals/Minerals
Not stated.

Geology/Mineralisation
Gold resources at the mine are classified as epithermal in terms of mineralisation style. The gold is hosted in a network of small (generally less than 2 cm wide) quartz-carbonate veins rich in sulphide minerals, strongly associated with micron-sized pyrite grains. The deposits formed between 455-million and 435-million years ago in the Macquarie Arc – an ancient volcanic arc. Gold is hosted in the Cowal Igneous Complex, a mix of sedimentary rocks and lavas intruded by plutonic igneous rocks. The Muddy Lake Diorite is a key host of gold. The deposits occur within a 5 km × 2 km trend known as the Gold Corridor.

Reserves
As at December 31, 2024, ore reserves (contained gold) comprised 134.6-million tonnes grading 1.03 g/t gold.

Resources
Total mineral resources (contained gold as at December 31, 2024), were estimated at 285.1-million tonnes grading 0.98 g/t gold.

Type of Mine
Openpit and underground.

Mining Method
The Cowal operation uses conventional drill-and-blast, load-and-haul methodologies, mining nominally 9 m blast benches as 3 m × 3 m flitches for the openpit and sublevel longhole open stoping underground with paste backfill.

Major Infrastructure/Equipment
The mine includes a nine-million-tonne-a-year processing plant, a primary gyratory crusher, a semiautogenous grinding mill, ball mill, steel grinding media, and recycle crushing, mineral liberation and refining equipment operations.

Mining equipment for the openpit operation includes dump trucks, primary and secondary excavators, dozers, loaders, water carts, graders, production drill rigs, and a grade control drill rig.

Mining equipment for the underground operation includes loaders, trucks, and drills.

Prospects
Regulatory approval has been secured to extend openpit mining operations by ten years and overall operations until 2042, with the mining lease extended to 2045. The openpit continuation project aims to develop the existing E42 pit and three new satellite pits, contributing an additional two-million ounces of gold production over the next ten years.

Continued growth is expected from high-grade underground orebodies that remain open at depth. 

Further, significant exploration potential exists at existing operations and near-mine, targeting epithermal gold and porphyry copper/gold prospects. 

Contact Details
Evolution Mining
Tel +61 2 9696 2900
Cowal site, tel +61 2 6975 4600 
Website evolutionmining.com.au