At Mount Lyell Mine underground sub-level caving mining is carried out at 1000 meters below the original surface (600 meters below 0m Australian height datum 2000RI). The mine production is about 2.7 million tonnes per annum of copper ore at 1.25% copper grade. The copper ore also contains 0.3 grams gold and 3 grams silver per ton of ore.

CMT mined and treated almost 2.12 million tonnes of ore to produce 23,777 tonnes of contained copper concentrate in 2009-10.

Mined ore is transported by trucks to underground primary crusher and Primary crushing takes place underground and ore is then automatically hoisted up a 600 metre shaft to be transported to the concentrator on a 1.2 kilometer overland conveyor belt.

The Main Decline extends 6.5 km from surface to 1000 meters below surface.

Potential development includes Western Tharsis with a 10.3MT ore at 1.3%Cu and is open at depth. Feasibility studies are currently in progress.