The Antapaccay mine is located 9.4 kilometres southwest of CMA's (Compañía Minera Antapaccay S.A.) past-producing Tintaya mine, and the Antapaccay concentrator is located 4.5 kilometres south of the Tintaya concentrator.

The CMA property also includes the Coroccohuayco project, a satellite deposit that is located within 10 kilometres of the Antapaccay plant. At this stage, exploration and drilling at Coroccohuayco has focussed on defining Mineral Resources and no mining activities are being undertaken.

The Antapaccay project contains a porphyry-skarn type (copper-silver-gold) deposit located in the Eocene-Oligocene Andahuaylas-Yauri strip, 9.4 kilometres southwest in a straight line from the Tintaya mine, in the area of the old Atalaya mine. The Eocene-Oligocene Andahuaylas-Yauri strip is located 250 to 300 kilometres west of the current Peru-Chile Trench, above a thick cap of sialic crust (50 to 60 kilometres), in a transitory zone between the flat subduction slab of central Peru and the normal subduction of southern Peru and northern Chile and immediately to the southeast of the Abancay deflection. It consists geologically of a thick cretaceous sedimentary sequence folded during the Andean deformations and widely intruded by stocks, sills and dykes of Andahuaylas-Yauri batholith, covered by Cenozoic lacustrine and volcanic deposits and quaternary deposits.

The copper mineralisation at Antapaccay is mainly contained in intermediate intrusive rocks with dissemination, veinlets, hydrothermal breccias which are in contact with pre-mineral rocks such as diorites and sedimentary rocks (limestones, calcareous shales, siltstones and sandstones), forming contact mineralised breccias, exoskarn and stockwork in sedimentary bodies with a clear predominance of chalcopyrite over bornite up to 350 metres; the roles reverse at a greater depth and are associated with a level of anhydrite-gypsum.

The main copper bearing minerals at Coroccohuayco are bornite, chalcopyrite and chalcocite, with the host rock consisting of Cretaceous sedimentary rocks of the Ferrobamba and Mara formation intruded by monzonitic plutons of the Eocene-Oligocene Andahuaylas-Yauri batholiths. The Coroccohuayco deposit is dominantly a skarn-hosted deposit, whereas the Antapaccay deposit is dominantly porphyry-hosted.

The Antapaccay mine is an open pit mine (consisting of a North pit and a South pit) with truck and shovel operations that provide a total annual material handling capacity of approximately 140 million tonnes of material. Major equipment includes a fleet of owner-operated 400 short ton class trucks, 48 cubic metre and 35 cubic metre rope shovels, dozers and loaders, as well as support equipment. Ore is mined and sent to the primary crusher located at the mine and the crushed ore is subsequently transported to the coarse ore stockpile by an overland conveyor of approximately 6.8 kilometres. The feeders at the coarse ore stockpile convey the crushed ore to the Antapaccay plant for processing. A portion of the material from the coarse ore stockpile is transported to the Tintaya plant using mining trucks.

The current life of mine plan contemplates that the Antapaccay mine will operate until 2029, plus one additional year of stockpile processing. The Antapaccay plant will operate until 2030 and the Tintaya plant will operate until 2029. There is the potential to extend the mine life beyond 2029 through additional exploration on the CMA property.

The Antapaccay metallurgical plant consists of a semi-autogenous grinding mill and two ball mills to prepare feed for a conventional flotation circuit to recover the copper, gold and silver contained in the feed ore into a copper concentrate. The Tintaya metallurgical plant consists of multi-stage crushing followed by ballmilling to prepare feed for a conventional flotation circuit to recover the copper, gold and silver contained in the feed ore into a copper concentrate. The nominal throughput of the Antapaccay and Tintaya plants are currently approximately 80,000 and 20,000 tonnes per day, respectively. Installation of additional flotation capacity, expected to be completed by mid-2016, will increase throughput at the Antapaccay plant to approximately 85,000 tonnes per day.

The copper concentrate produced from both processing plants is thickened and filtered on site prior to being trucked approximately 355 kilometres to port facilities at the Port of Matarani, operated by TISUR, for shipment to smelters.

Flotation tailings are thickened and delivered to the Tintaya open pit for disposal. The fully-permitted tailings dam storage capacity is sufficient for the current Antapaccay life of mine plan and options to increase height for extended capacity are being studied.