The primary sulphide minerals encountered at the Pinto Valley Mine are chiefly pyrite and chalcopyrite with minor amounts of molybdenite. Gold and silver are recovered as by-products. Sphalerite and galena occur locally in very small amounts. Alteration of silicate minerals of the host rocks to other groups of minerals due to the presence of hydrothermal fluids associated with the Cu-Mo-bearing intrusive rocks include potassic, argillic, sericitic, and propylitic alteration suites.

Sulphide minerals generally occur in veins and microfractures and less abundantly as disseminated grains, predominantly in biotite sites. The ore zone grades outward into a pyritic zone with higher total sulphide content. Molybdenum distribution generally reflects copper distribution, with higher molybdenum values usually found in the higher grade copper zones. Oxide mineralization and a supergene enrichment blanket was developed at the Pinto Valley Mine, but these areas have since been mined.

Sulphide deposition at Pinto Valley is controlled to some extent by the host rock. The sulphide content decreases in Precambrian aplite intrusions. Aplite usually contains less than 0.25% copper, whereas adjacent Quartz Monzonite may have as much as 0.6% copper. The deficiency of copper in aplite is probably due to the absence of biotite, which makes up about 7% of Quartz Monzonite. Disseminated chalcopyrite shows an affinity for biotite, where it is disseminated through the biotite or partially replacing it. Additional chalcopyrite is also present in veins cutting both rock types.

Pinto Valley copper mine is an open-pit mine with conventional processing facilities and an SX/EW plant for low-grade copper extraction. The Pinto Valley Mine, which restarted in December 2012, uses a conventional drill and blast, and truck and shovel fleet. The pit is mined in 14 m benches with a double bench configuration in deeper zones.

The processing facility consists of three crushing stages, ball mills, copper flotation stages, a molybdenum flotation circuit, and associated thickeners for concentrates and tailings. Two previous tailings dams have been rehabilitated and two tailings dams are currently operational. Pinto Valley also has an SX/EW facility that processes pregnant leach solution from low copper grade material that is leached. The SX/EW accounts for less than 5% of production.