Mining

Overall Site Plan

Mining

The mining operations will consist of a conventional drill-and-blast, load-and-haul operation. Ore will be trucked from the mine quarry to the nearby ore processing stockpile over a new heavy haul road. The ore will be reclaimed by a loader and fed to the crushing plant.

Development of the Rhyolite Ridge quarry will occur in two stages:

• Quarry Stage 1 – Starter Pit. An initial starter pit will be developed in the southwestern part of the ore body to supply ore for the first 4.5 years of the Project. In this area, lithium grades are 15% higher than the average grade for the deposit and the ore is more exposed at surface.
• Quarry Stage 2. Development of the greater pit will start once the environmental permits for this development have been granted. The Stage 2 pit design will facilitate a larger mining area to be maintained, aiding the efficiency of the operation for another 21 years. Stage 2 will involve expansion to the south and east. Finally, mining will progress to the north of the deposit. The Stage 2 pit requires prestripping to begin in year 4.

Pit Development Stage 1 (Starter Pit) and Stage 2

Owner mining is planned to be undertaken utilising a highly automated equipment fleet which will provide a lower operating and capital cost, while minimising injury and safety related incidents. In order to optimise operations, the mining fleet will be equipped with high precision GPS and real time analytics, allowing excavator and wheel loader operators to know what type of material is being loaded.

Ioneer will capitalise on current mining advances to enhance project performance including:

• Haul Truck Automation. Ioneer will become the first greenfield site in the U.S. to use automated haul trucks in the initial operation. This has shown to have several advantages in operating and capital costs in addition to minimising safety incidents.
• Mining Selectivity. To minimise the effects of loss and dilution in the mining operation, an accurate geologic model, high-precision GPS, competent operators, and a fleet management system (FMS) will be used. These packages will allow excavator and wheel loader operators to know in real time what type of material is being loaded.

The Rhyolite Ridge lithium-boron ore zone is increasing in grade and shallowing to the south, meaning the delineation of additional ore to the south, outside of the current Mineral Resource, is likely and would be expected to have a significant positive impact on the mine plan and project economics. Access to the southern extension of the deposit for drilling was not possible during the previous drilling campaign due to statutory limits on surface disturbance during the exploration phase. This area is scheduled for drilling once the necessary permits are in place, expected in 2Q 2021.