Uranium advisory at the Cebolleta Project

In recent years, uranium has been formally recognized as a US Critical Mineral, and certain uranium projects have been designated under the federal FAST-41 program for coordinated permitting and enhanced federal transparency. This federal prioritization has renewed strategic interest in historic uranium districts, including the Grants Mineral District (New Mexico), prompting both government agencies and junior mining companies to re-evaluate legacy resources within a more structured federal permitting framework.

The Cebolleta Project, located within the Grants Mineral Belt of west-central New Mexico, is a historically significant uranium-producing region within the broader Grants Mineral District. Separately, advanced-stage uranium projects such as the Crownpoint-Churchrock and La Jara Mesa developments in New Mexico have been reported as designated FAST-41 covered projects, meaning they receive full FAST-41 coordinated permitting support. Collectively, these projects underscore the continued strategic relevance of the Grants Mineral Belt to U.S. critical mineral policy and domestic uranium supply initiatives.

Challenge

Cebolleta is a uranium exploration project located in the northeastern corner of Cibola County, 10 miles north of Laguna, NM. The property is one of the few uranium assets in New Mexico that sits on privately held land under an 1884 Spanish land grant. The Project is held under a valid mining lease with the Cebolleta Land Grant (CLG), which provides mineral and surface rights through 2029, subject to extension and regulatory approvals. Development remains subject to applicable State and Federal permitting requirements

Ownership of this project contacted SLR’s mining advisory team to help them to review/evaluate and update the mineral resource estimate and prepare an updated Mineral Resource Estimate and Preliminary Economic Assessment (PEA) in accordance with NI 43-101 disclosure requirements.

At the time SLR was engaged, the project was owned by American Future Fuel. In June 2024, the project was acquired by Premier American Uranium, which continued the engagement and supported SLR’s ongoing technical work.

Solution

The project owner engaged SLR’s Mining Advisory team, recognized globally for delivering defensible Mineral Resource Estimates and advancing projects through independent Preliminary Economic Assessments (PEAs). With the stated objective of returning Cebolleta to operational uranium production, SLR initiated work to update and re-establish the project’s Mineral Resource estimate in support of future development planning.

Assessing historical drilling information

Modern reporting standards require not only confirmation of historical data, but also demonstration that any resource has reasonable prospects for eventual economic extraction. This drove the need to verify legacy drilling and establish a foundation for evaluating mining and processing options.

From August to November 2023, drilling was completed to confirm stratigraphy, mineralization thickness, and grade continuity of historical drilling. With the historical information confirmed, SLR developed 3D models of the project to help ownership understand and plan next steps.

Addressing logistical challenges and future processing opportunities

After verifying that the historical data in place was accurate and had been applied to 3D models to support operational understanding, SLR moved into the next phase of advisory: feasibility. As part of this work, SLR assessed multiple mining scenarios, including updated open-pit and underground concepts, before evaluating alternative processing pathways.

One of the challenges this and other New Mexico uranium mining sites face is a lack of existing processing infrastructure. What had been present during the uranium mining boom, which lasted from the 1950s to the 1990s, were shuttered, meaning there are no local processing facilities to process extracted ore. The PEA evaluated an on-site crushing and heap leach processing facility utilizing resin-in-column recovery.

SLR’s solution: Heap leach mining

Heap leaching is a mining process in which crushed ore is stacked on a lined pad and irrigated with a leaching solution, often cyanide for gold or sulfuric acid for uranium, that dissolves the target metal as it percolates through the heap. The metal-rich solution is collected at the base and processed to recover the metals. It is widely used for low-grade ores because it is relatively low-cost and scalable.

Heap leaching of uranium fell out of favor primarily due to prolonged uranium price weakness, particularly following the post-1970s market collapse and again after the Fukushima Daiichi nuclear disaster, which reduced margins below the capital and operating thresholds required for pad construction and acid consumption. At the same time, in-situ recovery (ISR) emerged as a lower-cost, lower-disturbance alternative for suitable roll-front deposits, displacing many conventional mining and heap leach operations. Increasing environmental compliance requirements, extended permitting timelines, bonding obligations, and site-specific metallurgical challenges such as elevated acid consumption or poor percolation further constrained project competitiveness. As a result, heap leaching was historically viewed as uneconomic for recovering residual uranium from previously mined material.

However, advances in leach technology, improved process control, and stronger uranium price conditions have renewed its viability. At Cebolleta, application of modern technology and SLR’s deep bench of heap leach specialists enabled re-evaluation of historical processing methods and mineralized material, resulting in a recommended mining and processing strategy. SLR developed an updated mine plan, production schedule, and financial model.

Impact

SLR’s work continues to date and has contributed to renewed evaluation of uranium development opportunities in the United States. At Cebolleta, the project has progressed from a legacy uranium property with historical mining activity to a technically supported, PEA-stage project in New Mexico.

SLR completed an updated NI 43-101 Technical Report with an effective date of May 14, 2025, including a Preliminary Economic Assessment (PEA).

Over approximately three years, SLR validated historical drilling data, updated the Mineral Resource Estimate, and developed a PEA-level mine plan and economic model, transitioning the project from a legacy uranium property to a technically supported, PEA-stage project.

Disclaimer and references:

All scientific and technical information included in the above summary has been derived, in part, from, and in some instances extracted from, the technical report entitled “NI 43-101 Technical Report on the Preliminary Economic Assessment, Cebolleta Uranium Project, Cibola County, New Mexico, USA” (the “Cebolleta Technical Report”) prepared by SLR for Premier American Uranium Inc. with an effective date of May 14, 2025. The summary above is subject to all the assumptions, qualifications and procedures set out in the Cebolleta Technical Report and is qualified in its entirety by reference to the full text of the Cebolleta Technical Report. For full technical details of the report, reference should be made to the complete text of the Cebolleta Technical Report, which has been filed with the applicable regulatory authorities and is available under Premier American Uranium’s SEDAR+ profile at www.sedarplus.ca.

See also https://premierur.com/new-mexico/cebolleta-project/