The current Mineral Resource estimates for Rhyolite Ridge are detailed in the announcement titled "Rhyolite Ridge Mineral Resource Upgrade" dated 26 June 2019.
The total lithium-boron Mineral Resource for the South Basin at Rhyolite Ridge is now estimated (at a cut-off grade of 5,000ppm boron) to contain:
- 154.0 million tonnes at 1,650ppm lithium (equivalent to 0.9% lithium carbonate) and 14,100ppm boron (equivalent to 8.0% boric acid); and
- 1.3 million tonnes of lithium carbonate and 12.4 million tonnes of boric acid.
High-grade lithium-boron mineralisation is the focus of the Rhyolite Ridge DFS as it represents the highest value material and simplest to process. This is due to the low-clay and high-searlesite content of the rock, which makes the lithium-boron ore amenable to low-cost acid leaching.
The previous Mineral Resource estimates for Rhyolite Ridge are detailed in the announcement titled “Updated Rhyolite Ridge Mineral Resource Statement” dated 23 October 2018.
Located on only part of the western side of the South Basin, the Mineral Resource remains open to the north, south and east and has significant potential to expand with further drilling of the South Basin.
US Borax discovered significant amounts of lithium and boron in the North Basin during the 1980's. Two holes have been drilled by ioneer in the North Basin and further drilling will be necessary to estimate an initial Mineral Resource for this large area.