Name of the Project
Santa Cruz underground copper mine.

Location
The Santa Cruz project is located on about 6 000 acres of 100%-owned private surface, mineral and associated water rights, in Arizona, in the US.

Project Owner/s
Copper developer Ivanhoe Electric. 

Project Description
Ivanhoe Electric's prefeasibility study (PFS) for the Santa Cruz copper project, completed in June 2025, defines a high-quality underground mining operation designed to produce 99.99%-pure copper cathode for the US market.

The project has probable mineral reserves of 136.17-million tonnes at 1.08% total copper, containing 1.47-million tonnes of copper. These reserves support a 23-year mine life. Additional indicated resources, excluding reserves, contain a further 1.5-million tonnes of copper, while inferred resources across the Santa Cruz, East Ridge and Texaco deposits contain a further 3.3-million tonnes of copper.

Santa Cruz is planned as a 20 000 t/d bulk-tonnage underground operation, with mining primarily using longhole stoping and local drift-and-fill methods. Production is expected to average about 72 000 t/y of copper cathode during the first 15 years of mining, with total life-of-mine copper production estimated at about 1.36-million tonnes.

Ore will be processed using a conventional chloride-assisted on/off heap-leach process, followed by solvent extraction and electrowinning. The PFS estimates copper recoveries of 92.2% over the life-of-mine. Up to 50% of the spent ore is expected to be converted into paste and used as underground backfill, avoiding the need for a tailings storage facility.

In May 2026, Ivanhoe Electric announced plans to acquire a Robbins Crossover XRE tunnel boring machine (TBM) and materials handling system for decline development at Santa Cruz. The TBM will be used to excavate a 4-km-long single decline and is intended to derisk access development through variable ground conditions. 

Ivanhoe Electric has said the TBM decline development plan does not affect the rest of the project design, including the mining method, mining rates and surface processing described in the 2025 PFS.

Potential Job Creation
Not stated.

Net Present Value/Internal Rate of Return
At a base-case copper price of $4.25/lb, the project has pretax net present value (NPV), at an 8% discount rate, of $1.9-billion and an internal rate of return (IRR) of 22%.

At a copper price of $4.83/lb, the after-tax NPV increases to $2.6-billion and the IRR to 26.6%.

Capital Expenditure
Initial project capital is estimated at $1.24-billion.

The Robbins TBM and materials handling system, including refurbishment, is expected to cost about $64.7-million. Ivanhoe Electric has indicated that the TBM system replaces capital associated with roadheader decline development, silica gel grouting and the Railveyor materials handling system included in the 2025 PFS, with a projected net impact on initial project capital of less than $20-million.

Ivanhoe Electric is pursuing project financing through several avenues, including the Export-Import Bank of the United States, commercial lenders and potential nondebt funding sources.

Planned Start/End Date
Ivanhoe Electric received approval of the Site Development Plan from the City of Casa Grande in March 2026.

Excavation of the box cut is scheduled to start in the third quarter of 2026. Arrival and assembly of the TBM on site are expected to begin in the first quarter of 2027, followed by the start of decline development in the third quarter of 2027.
Underground mine development is scheduled to start in the third quarter of 2028, with first oxide copper ore expected to be placed on the heap-leach pads in the fourth quarter of 2028. First copper cathode production is now expected in the second quarter of 2029.

Latest Developments
Ivanhoe has said it has all necessary permits to start initial construction activities.

The company announced on May 11, 2026, that it intended to acquire a purpose-built Robbins Crossover XRE TBM and materials handling system from The Robbins Company for use at Santa Cruz. The final purchase remains subject to definitive agreements, which are expected before the end of May 2026.
Robbins will overhaul and upgrade the machine, including a refurbished 9.3-m-diameter cutterhead manufactured in Ohio and customised features for Santa Cruz's geological conditions. 

The TBM is designed to excavate the planned 4 km decline in about 12 months.

The revised decline-development approach removes the need for a Class V underground injection control permit for silica gel. Ivanhoe Electric is preparing an updated S-K 1300 and National Instrument 43-101 technical report to incorporate the TBM and materials handling system, with completion expected in the third quarter of 2026.

Key Contracts, Suppliers and Consultants
Fluor (project lead); BBA USA Inc (reserves, underground mine planning and economic analysis consultant); KCB Consultants (heap-leaching consultant); Paterson & Cooke USA (paste backfill consultant); MET Engineering (metallurgical testing consultant); INTERA Incorporated (hydrogeology consultant); and The Robbins Company (TBM and materials handling system for decline development, subject to definitive agreements).

Contact Details for Project Information
Ivanhoe Electric, tel +1 480 656 5821 or email info@ivanhoeelectric.com.