Rare earth and barite mineralisation at Ngualla is magmatic in origin and hosted within the core of the Ngualla Carbonatite. Mineralisation has been residually enriched in the oxide zone at surface through weathering and the removal of carbonate minerals to variable depths of up to 140 m vertically.

High-grade rare earth mineralisation is hosted within the iron oxide and barite-rich weathered zone and above an irregular karstic surface, referred to as the Weathered Bastnaesite Zone. For modelling purposes, upper grade thresholds of 0.69% P2O5 and 13.99% CaO have been used to assist with the definition of Weathered Bastnaesite Zone Mineral Resource subset reported, which has been found through test work to be most amenable to the current metallurgical extraction process.

Mining studies indicate the viability of a modest sized but long life open pit operation with a low Life of Mine (LOM) waste strip ratio of 1.78, which at the proposed production rate can provide sufficient feed for an initial project life of 26 years based solely on the Weathered Bastnaesite Zone portion of the greater Ngualla deposit.

As the mineralisation is weathered and at surface, mining will predominantly (70%) be free dig requiring minimal blasting and with low Ore to waste stripping ratios.

Mining losses and dilution are expected to be minimal due to the thick blanket morphology of the deposit and the use of small mining equipment operating at a relatively low mining rate averaging less than 1.9Mt total material movement per annum over the life of mine. Total mining losses comprise just 6% of the total Mineral Resource available (Measured + Indicated categories of the +1% REO Weathered Bastnaesite Zone).

The pit optimisation was undertaken using GEMCOM Whittle 4X software utilising the February 2016 Ngualla Mineral Resource model completed by SRK Consultants Pty Ltd. The overall slope includes an allowance for a 15m wide catch berm every 20 vertical metres in oxide material and the oxide / fresh transition zone. This results in the very shallow 25° slope applied in the oxide and 34° in the oxide / fresh zone. A 23m wide ramp has been incorporated into the design suitable for a dual lane ramp based on the 65t dump truck selected.

The run of mine (ROM) feed is delivered to stockpiles allowing for blending based on grade and mineralogy. A front end loader reclaims from the stockpile and feeds directly to a ROM bin which is fitted with a static grizzly to scalp out oversize rock. Feed is withdrawn at a controlled rate from the bin by an apron feeder, which in turn transfers onto a vibrating grizzly feeder to scalp out fines. Scalper oversize is fed to a tooth rolls mineral sizer, which breaks rocks down to a notional top size of 200mm and is combined with scalper undersize on the discharge conveyor. The feed is then conveyed directly to the grinding circuit.

The crushed material is initially milled in a high aspect open circuit SAG mill, with slurry passing through discharge grates and a trommel. The trommel undersize slurry flows into a common hopper shared with the closed circuit secondary ball mill. The hopper discharge is pumped to a pack of hydrocyclones with the underflow reporting back to the secondary mill.

Peak has designed a Multi-Stage Processing Plant that will be located on site at Ngualla to produce 32,700 tonnes per annum of rare earth concentrate grading 45% REO. The plant comprises the following:

-A ROM pad to receive mine production and blend plant feed to predefined specifications.
-A comminution circuit incorporating primary crushing, grinding and classification.
-Beneficiation of the ground feed utilising reverse gangue flotation, regrinding and rare earth flotation to produce a high grade/low mass concentrate.
-A segmented Tailings Storage Facility (TSF) for safe disposal of waste solids and water reclaim.

The ground material is conditioned in two high intensity conditioning tanks with flotation reagents prior to being presented to barite flotation. The circuit consists of a rougher bank, with the rougher concentrate being further upgraded in two stages of cleaner flotation.

The flotation concentrate from the Barite Pre-flotati ........