This report presents the preliminary economic assessment recovery methods for the Cebolleta Uranium Project, based on a November 2025 technical report.
Report context
This technical report is dated November 13, 2025 (SLR Project No.: 123.020578.00001) and documents a preliminary economic assessment (PEA) for the Cebolleta Uranium Project, prepared for Premier American Uranium Inc. The recovery methods section describes the proposed processing route for mineralized material to be mined by underground and open-pit mining methods.
Processing route
Crushing circuit
The proposed recovery process begins with a mobile two-stage crushing circuit. The report lists three crushing stages among the major unit operations: primary crushing, secondary crushing, and tertiary crushing.
Heap leaching
Crushed product will be conveyor-stacked on a heap leach pad (HLP) in lifts and irrigated with a diluted sulfuric acid solution. A total leach cycle of 90 days has been assumed for the heap leach system. After the 90-day leach cycle, irrigation will be discontinued and advanced to the next cell. No rinse phases are included because of the multiple lift system employed. Subsequent lifts will be placed on top of the previous lift, to a maximum height of 90 ft. Rinsing will be conducted as part of the final closure.
The leach solution will have an approximate concentration of 0.05 lb/gal sulfuric acid when applied to the heap. Sulfuric acid consumption is estimated to be 20 lb/st. A vertical submersible pump at the barren tank will be used for the barren solution application to the heap. The average flow to the heap will be 646 gpm.
A preliminary design of the heap leach pad area was used for this PEA. The pad will be constructed in phases and will hold approximately 10.5 Mst.
Sulfuric acid will percolate through the heap, and the pregnant leach solution (PLS) will be collected and transferred to a pregnant solution tank in the recovery building. Other metals such as mercury will also be leached by the sulfuric acid.
Ion exchange (I/X) circuit
PLS will be pumped to a series of four 530 ft³ ion exchange (I/X) columns: four online with two of the columns on standby. The resin columns are loaded with uranium over one day (1.0 columns per day). The number of columns taken offline is one column per day. Every three days, three columns weighing approximately 16 tons each will be shipped off site. When a column is taken out of service, it will be replaced with a new I/X column. Every day a single column will be taken out of service and replaced with a new I/X column.
Loaded resin will be sent to a third-party for processing.
Process control measures
The uranium-bearing pregnant solution will flow by gravity to the adsorption circuit (I/X column) to recover uranium but may be bypassed to the pregnant solution pond in the event of a precipitation event. Further upset can be stored in the Overflow Pond. Make-up sulfuric acid and water from the barren solution pond may be added to the barren solution tank, before recirculating the solution back to the heap by pumping. Use of raincoats (impermeable geomembrane covers) on the heap, backup power supply for pumps, and containment surge volume within the process water ponds are some of the means to address storm upset in the system.
Key reported parameters
| Parameter | Value | Unit | Basis |
|---|---|---|---|
| Heap leach cycle time | 90 | days | Assumed for design |
| Sulfuric acid application concentration | 0.05 | lb/gal | Design value |
| Sulfuric acid consumption | 20 | lb/st | Estimate |
| Heap irrigation application rate | 0.004 | gpm/ft² | Average rate |
| Average flow to heap | 646 | gpm | Design flow |
| Maximum heap height | 90 | ft | Design basis |
| I/X column volume | 530 | ft³ | Design |
| I/X online columns | 4 | , | Design |
| I/X standby columns | 2 | , | Design |
| Column loading cycle | 1.0 | columns per day | Design |
| Columns shipped off-site (every 3 days) | 3 | columns | Design |
| Column weight | ~16 | tons each | Design |
| Heap leach pad design capacity | ~10.5 | Mst | Preliminary design (PEA) |
Project website: https://premierur.com/new-mexico/cebolleta-project/
Technical qualifications
The report states that a preliminary design of the heap leach pad area was used for this PEA. The total leach cycle of 90 days has been assumed for the heap leach system. The sulfuric leach solution may be applied to the pad at an average application rate of 0.004 gpm/ft². The sulphuric acid consumption is estimated to be 20 lb/st. All processing information presented is from a preliminary economic assessment and represents proposed design parameters rather than historical operating data or testwork results.
Source: “Cebolleta Uranium Project , NI 43-101 Technical Report on the Preliminary Economic Assessment”, November 13, 2025, Section 17.0 Recovery Methods, Premier American Uranium Inc.
