Rio Tinto’s Resolution Copper spend: underground design and drilling notes for engineers
Reviewed by Tom Sullivan
First reported on International Mining – News
30 Second Briefing
Rio Tinto has approved a $144 million investment for the next development phase of the Resolution Copper project in Arizona, with $79 million attributable to its share, targeting one of the world’s largest undeveloped copper orebodies. Funding will cover additional underground development and critical equipment to deepen exploration and geotechnical drilling below the existing infrastructure. The move signals continued commitment to progressing permitting and shaft work at a deposit expected to be a major long-term source of US domestic copper supply.
Technical Brief
- Approach reflects a common staging pattern in large US copper projects: incremental underground development ahead of full construction sanction.
Our Take
JPMorgan’s separate analysis in our database flags Resolution in Arizona as the single largest contributor to a potential doubling of US copper output, so Rio Tinto’s $79 million share of this spend is effectively de‑risking a project that could shift the national copper supply balance.
The linked feasibility and underground equipment work at Resolution sits alongside Rio Tinto’s other late‑stage copper and critical minerals items in our coverage, suggesting the company is prioritising large, long‑life North American copper over greenfield options in higher‑risk jurisdictions.
With 313 copper‑tagged pieces in our database but relatively few US underground mega‑projects, Resolution stands out as one of the only domestic assets where investment in bespoke underground fleets and water treatment is being advanced at this scale.
Prepared by collating external sources, AI-assisted tools, and Geomechanics.io’s proprietary mining database, then reviewed for technical accuracy & edited by our geotechnical team.
Related Articles
Related Industries & Products
Mining
Geotechnical software solutions for mining operations including CMRR analysis, hydrogeological testing, and data management.
Construction
Quality control software for construction companies with material testing, batch tracking, and compliance management.
CMRR-io
Streamline coal mine roof stability assessments with our cloud-based CMRR software featuring automated calculations, multi-scenario analysis, and collaborative workflows.
HYDROGEO-io
Comprehensive hydrogeological testing platform for managing, analysing, and reporting on packer tests, lugeon values, and hydraulic conductivity assessments.
GEODB-io
Centralised geotechnical data management solution for storing, accessing, and analysing all your site investigation and material testing data.


