The Nolans Bore deposit is spatially close to several tin and tantalum pegmatites, and REE-bearing carbonatite/alkaline complexes (Mud Tank and Mordor Igneous Complex). This mineral field of carbonatites, pegmatites, and other REE occurrences is in a region transacted by three major lineaments delineated by O’Driscoll, which include the north–northwest trending G2-gravity lineament that is considered to be spatially related to the Olympic Dam deposit and northwest-trending G3-gravity.

The mineralisation at the Nolans Bore deposit is hosted in a series of east-northeast trending, and steeply dipping to the northwest, fluorapatite veins and breccia zones. The granite-gneiss host has been strongly kaolinised due to weathering.

Huston et al. (in press) describe four styles of mineralisation: massive fluorapatite veins that typically contain 4–6% REE oxides and constitute most of the defined resource; very high-grade (7º–10% REE oxide) zones found in cheralite-bearing, apatite-poor kaolinitic zones outside of the veins; apatite allanite epidote zones hosted by calc-silicates; and low-grade stockwork zones in gneiss and kaolinitised rock adjacent to the veins and mylonite zones.

The mining method selected is open cut utilising conventional hydraulic excavator and haul truck fleets. The open pits will be developed using multiple stage pit designs, all of which have been completed to a FS standard. Ramps are designed at 1 in 10 gradient, 30m wide except for lower pit levels and small sub-pits where the ramps are designed at 21m wide.

The overall pit slope angles in the final stage of pit design vary between 34° and 45°, including allowances for pit access ramps.

The beneficiation, phosphate extraction, rare earth extraction, rare earth purification and separation circuits will operate largely independently, allowing the stabilisation of each section to proceed more easily and providing a significant improvement in the ramp-up to full production.

The process plant has been designed for 340,000 tpa of concentrate which relates to a nominal 4,518 tpa NdPr oxide with a potential maximum of approximately 4,700 tpa depending on the mining schedule.

The by-product of the process will be P2O5 contained in merchant grade (MGA) phosphoric acid with an average annual production of 77,972 tpa P2O5 in 144,393 tpa of MGA phosphoric acid.

Ore from the ROM pad will be transported approximately 8.5 kilometres south to the process plant. The design for the DFS includes the following areas:
• Comminution and Beneficiation – ROM ore will be crushed, milled and beneficiated using flotation to produce a concentrate, which will ........