Name of the Mine
Pinto Valley mine.

Location
The Pinto Valley mine is located in the Globe-Miami mining district in Arizona, in the US.

Mine Owner/s
Capstone Copper Corp owns and operates the Pinto Valley mine.

Brief Description
The Pinto Valley mine is a large-scale openpit copper mining operation. It is one of the biggest copper mines in the US, with a significant yearly production capacity. The operation is known for its long mine life, with reserves and resources that support continued operations for several decades.

Brief History
The Pinto Valley mine has a long history dating back to the early 1970s when it was first developed by Cities Service Company. The mine has changed ownership several times over the years, with Capstone Copper acquiring it in 2013. Since its inception, the mine has undergone multiple phases of expansion and modernisation to improve its efficiency and output. Significant investments have been made to extend the mine’s life and enhance its processing facilities.

Primary Metals/Minerals
Copper.

Secondary Metals/Minerals
Molybdenum.

Geology/Mineralisation
Pinto Valley is a copper porphyry deposit. The primary host rock is the Precambrian-age Lost Gulch Quartz Monzonite (equivalent to the Oracle granite or Ruin granite). The deposit’s economic mineralisation is a hypogene orebody with chalcopyrite, pyrite and minor molybdenite as the only significant primary sulphide minerals.

Reserves
As of the latest estimates, the Pinto Valley mine has proven and probable copper reserves of about 335.97-million tonnes at an average grade of 0.32% copper and 0.007% molybdenum.

Resources
The mine had measured and indicated resources, inclusive of reserves, of 1.37-billion tonnes grading 0.29% copper and 0.005% molybdenum as at December 31, 2023. Inferred mineral resources, inclusive of reserves, were estimated at 149.79-million tonnes grading 0.27% copper and 0.006% molybdenum.

Type of Mine
Openpit.

Mining Method
Conventional openpit mining, using drilling, blasting, loading and hauling techniques.

Major Infrastructure/Equipment
The mine includes mine equipment maintenance facilities (north barn, main shop, wash bays, tyre change area); office complexes; heavy and light vehicle fuel storage and distribution facilities; an explosives plant; pit dewatering pumps and pipelines; concentrate dewatering, storage and loadout facilities; warehousing and change rooms; stormwater ponds and pumping systems; internal and access roads; water wells and water pumping systems; a first aid facility; an assay laboratory; power lines and transformers; tailings storage and distribution facilities; and waste dumps.

The processing facility comprises three crushing stages, grinding in six ball mills, copper flotation stages, a molybdenum flotation circuit, and associated thickeners for concentrates and tailings. The two existing tailings storage facilities will provide adequate tailings storage for the planned life-of-mine (LoM) until 2039.

Prospects
The mine received a new US Forest Service Mine Plan of Operations in November 2021 and is fully permitted to operate for the duration of the current LoM plan, which extends to 2039.

Pinto Valley is advancing a district growth study evaluating the inclusion of a portion of the one-billion tonnes of mineral resources into the mine plan. This study could result in a mine life extension until 2050. Pinto Valley is also evaluating near-mine district consolidation opportunities in one of the most prolific mining jurisdictions in the US.

Pinto Valley is also evaluating new mining technologies such as autonomous trucking. 

Contact Details
Capstone Copper Corp.
Tel +1 604 684 8894
Email info@capstonecopper.com

Sources
Capstone Copper Corp. Website: https://capstonecopper.com/