The MRP is classed as a carbonaceous-sedimentary hosted, supergene enriched, uranium deposit. Mineralisation is hosted predominantly by unconsolidated Eocene sediments (39 Ma) which are rich in organic matter and comprise river and estuarinelake sediments. The organic matter originated primarily from land-based plant matter that washed into the channels and deposited into tributaries along the edge of an oxbow bend, forming peat.

The uranium mineralisation is hosted by the organic matter in the reduced sediments below the redox front. Most of the uranium is adsorbed onto organic matter in an ionic form (i.e. uranium metal). The remainder of the mineralisation comprises
ultra-fine grained uraninite (UO2) and mixed uranium oxides. The individual uranium-rich units consist of stacked lenses that have strong lateral continuity, and are spatially associated with the redox front that coincides with the present-day water table. Uranium mineralisation is hosted by flat-lying, carbonaceous clastic sediments which are in turn overlain by weathered, oxidised sediments that range in thickness from 19m to 62m of waste overburden.

Most of the uranium is contained in the top mineralised lens (Figure 4.3). The ore zones are up to 38m thick, inclusive of interburden, with Ambassador and Princess deposits averaging 4.5m in thickness, and up to 8m in thickness at Shogun and Emperor with an average of 2.3m. Ambassador and Princess mineralisation is strongly polymetallic in nature, with the majority of base and other metals adsorbed on to organic matter, with sulphides and sulphates accounting for the remainder. None of the other metals occur in a form or concentration which allows for eventual economic extraction and are therefore not reported as a Mineral Resource under the JORC Code (2012).

The regular geometry of the mining operation, with a fixed distance from the active mine face and backfill, lends itself to either a truck and shovel (T&S) operation, or continuous mechanised waste haulage system such as an in-pit crushing and conveying (IPCC) system. Vimy has investigated a number of mechanised mining systems, including drag line, dozer trap, bucket wheel excavator, and IPCC. These mechanised mining options have progressively been eliminated due to excessive capital cost or technical risk. For the purposes of the DFS, it has been determined that an owner-operator T&S operation is the most cost-effective mining approach for the MRP.

There are also a number of smaller high-grade and secondary satellite pits within the MRP. A conventional T&S mining method will be utilised for these pits where mining proceeds bench-by-bench in a vertical direction from surface with dumping of waste material ex-pit on overburden surface landforms. This method will also be used within the larger deposits where pit geometries are less favourable for strip mining as described above.

It should be noted that the low unit mining cost is a result of the large ultra-class mining fleet selected, free-dig nature of the overburden and short haul distance across the pit floor due to the strip mining method adopted.

The process flowsheet includes a beneficiation plant operating in front of the main hydrometallurgical process plant described above, comprising the following unit operations:

BENEFICIATION PLANT:
- Mineral sizer primary crusher and log washer to pulp the ore;

- Ore screening to recover high-grade oversize comprising hard carbon lumps;

- Ore cycloning to recover fines comprising mineralised clays and carbonaceous sediments; and

- Gravity separation circuit to remove non- mineralised, heavy silica sand gangue.

HYDROMETALLURGICAL PROCESS PLANT:

The hydrometallurgical process plant has been designed and costed by GRES based on the process design criteria confirmed through continuous piloting. The estimate is supported by multiple budget quotations from OEMs. The process plant consists of the following major unit operations:

- SAG milling;
- Leach feed thickener;
- 6-stage uranium leach circuit;
- 8-stage RIP circuit;
- Resin elution;
- Resin elution reagents make-up;
- UF/NF plant;
- 4-stage Uranyl peroxide precipitation circuit; and
- Uranyl peroxide thickening, washing, drying and packaging.

The reagents area of the process plant has been designed and costed by GRES based on in-house experience and budget quotations from OEMs, with the plant consisting of the following major unit operations:

- Sulphuric acid vendor package plant and acid storage;
- Ferric sulphate generation and storage;
- Sodium chloride dissolution and storage;
- Caustic unloading and storage;
- Hydrogen peroxide unloading and storage; and
- Flocculant mixing and storage.