Santa Cruz underground copper mine, US

10th November 2023 By: Sheila Barradas - Creamer Media Research Coordinator & Senior Deputy Editor

Santa Cruz underground copper mine, US

Name of the Project
Santa Cruz underground copper mine.

Location
Arizona, in the US.

Project Owner/s
Ivanhoe Electric.

Project Description
Santa Cruz is currently not being mined.

An initial assessment and technical summary report on the project has shown a potential new source of "responsibly produced ‘green’ copper” to enhance US supply chain independence.

Mineral resources are stated for three deposits: Santa Cruz, Texaco and East Ridge. Total indicated and inferred resources are estimated at 100.24-million tonnes grading 1.63% soluble copper, 1.5% acid soluble copper and 0.41% cyanide soluble copper. For mine planning work, however, only the high-grade exotic, oxide and enriched domains of the Santa Cruz and East Ridge deposits have been evaluated.

Over the 20-year LoM, 105.2-million tonnes of mineralised material are expected to be mined. This includes 88.6-million tonnes from the Santa Cruz deposit, 1.9-million tonnes from the Santa Cruz exotic mineralisation, 9.8-million tonnes from the East Ridge deposit and 4.9-million tonnes of low-grade material required to access the deposits.

The proposed mine will target a combined production of 15 000 t/d from Santa Cruz and East Ridge.

The initial assessment includes potential LoM production of 1.59-million tonnes of copper contained in 99.99% pure cathode, and 48% copper concentrate with very low deleterious elements such as arsenic or lead. LoM copper recovered to cathode totals 1.03-million tonnes and LoM copper recovered to concentrate totals 555 000 t (65% copper in cathode, 35% copper in concentrate).

The report has determined that an underground longhole stoping method is suitable for the oxide and chalcocite-enriched domains within the Santa Cruz deposit.

The East Ridge deposit will be mined using drift-and-fill methods, with cemented waste-rock backfill for support. Future studies could evaluate the potential addition of the large primary sulphide domains at Santa Cruz (76.2-million tonnes indicated grading 0.88% total copper and 8-million tonnes inferred grading 0.92% total copper using a 0.70% cutoff grade), and at the Texaco deposit (900 000 t indicated grading 1.05% total copper and 35-million tonnes inferred grading 1.06% total copper using a 0.80% cutoff grade), subject to market conditions.

Potential Job Creation
Not stated.

Net Present Value/Internal Rate of Return
The project has a pretax net present value, at an 8% discount rate, of $1.64-billion and an internal rate of return of 25.1%.

Capital Expenditure
$1.15-billion.

Planned Start/End Date
Not stated.

Latest Developments
Not stated.

Key Contracts, Suppliers and Consultants
None stated.

Contact Details for Project Information
Ivanhoe Electric, tel +1 604 689 8765 or email info@ivanhoeelectric.com.