The copper deposits of the Capricorn Copper Mine (CCM) are situated within the Western Fold Belt of the Mount Isa Inlier. The Mount Isa Inlier consists of Early to Middle Proterozoic rocks, which are endowed with a variety of ore deposits, including the Mount Isa Pb–Zn–Ag and copper (Cu) deposits, Century Zn–Pb–Ag deposit, Cannington Ag–Pb–Zn deposit, and the Osborne and Ernest Henry iron oxide Cu–Au deposits.

The CCM project includes five deposits: Mammoth (MAM), Mammoth North (MAM_N), Esperanza-Pluto (ESP), Esperanza South (ESS) and Greenstone (GST).

The Capricorn Copper deposits (MAM, MAM_N, ESP, ESS and GST) are each at different stages of definition, development or mining. Copper mineralisation is related to a set of interconnected east to northeast-trending faults and fault splays associated with the regional scale, north-trending MGFZ. Mineralisation occurs as stockwork veins, breccias and as adjacent replacement of host rocks within and close to the faults.

Capricorn Copper Mine (CCM) has seven primary ore bodies contained within a 1.5km radius, with mining to occur from multiple ore bodies through two declines. The mining methods and extraction sequencing have been selected based on a detailed trade off study including economic analysis of individual ore bodies considering the suitability of the mining method, access of equipment and geological and geotechnical settings. From this study, Longitudinal Sub Level Caving (LSLC) was selected as the most appropriate method for Esperanza South (ESS). All other orebodies will be mined using Long Hole Open Stoping (LHOS) with paste fill.

The existing MAM portal provides access to Mammoth Deeps, Greenstone, Mammoth North, East and Pluto deposits. The Esperanza South underground mine is located to the southwest of the existing Mammoth workings. The orebodies are separated by approximately 1km (with the portals approximately 1.9km apart). The Esperanza South orebody has its own independent decline and supporting mine infrastructure.

Capricorn Copper Mine is targeting production of approximately 30ktpa of copper in copper concentrate. The grade of the copper concentrate is expected to be approximately 30% and will be transported to the Port of Townsville in sealed half height containers for international sale. To achieve this, CCM has developed strong geological and resource models that have supported the development of production plans with increased confidence and capacity to mine and process copper ore compared to previous operational periods at the mine.

The existing processing infrastructure at Capricorn Copper Mine is a collection of historical upgrades and modifications to the original process flow design, and reflects the different technologies employed to recover copper over decades of operation. The current process flow design is a conventional copper sulphide flotation concentrator and current works include a combination of refurbishment of existing equipment and some minor modifications to improve reliability and performance of the plant. These include the addition of a regrind mill, which will allow the plant to process up to 1.7Mtpa of ore from multiple ore sources. The metallurgical programs developed as part of the Restart Execution Studies (RES) have also identified improved operating strategies for the plant that, together with the refurbishment and upgrade programs, will allow the blending of ore from multiple sources with improved metallurgical performance to produce a high quality clean copper concentrate.

The concentrator flow sheet consists of:
- single toggle jaw crusher, feeding a Coarse Ore Stockpile (COS);
- comminution circuit comprised of a closed SAG and Ball Mill paired with a hydrocyclone cluster;
- rougher flotation circuit generating three separate rougher concentrates (high, middle, low grade);
- three cleaner flotation stages configured to produce a final concentrate;
- conventional thickeners for final concentrate and the flotation tailings dewatering;
- tailings disposal in the Esperanza Tailings Storage Facility (this facility is now full and no longer suitable for tailings storage) Esperanza Pit water treatment circuit.