ioneer Upgrades Rhyolite Ridge Mineral Resource Estimate

THE BOURSE WHISPERER: ioneer Ltd (ASX: INR) announced an updated Mineral Resource estimate for the company’s 100 per cent-owned Rhyolite Ridge lithium-boron project in Nevada, USA.

Ioneer has taken the total lithium-boron Mineral Resource for the South Basin at Rhyolite Ridge to be now estimated (at a cut-off grade of 5,000ppm boron) to contain:

154 million tonnes at 1,650ppm lithium (equivalent to 0.9% lithium carbonate) and 14,100ppm boron (equivalent to 8% boric acid); and

1.3 million tonnes of lithium carbonate and 12.4 million tonnes of boric acid.

The company said the update represents an increase of 200,000 tonnes of lithium carbonate and 3.8 million tonnes boric acid compared to the previous lithium-boron Mineral Resource estimate.

The updated Mineral Resource includes a maiden Measured Resource of 41 million tonnes at 1,700ppm lithium and 14,400ppm boron.

This contains a higher-grade Measured Resource of 27.5 million tonnes at 1,900ppm lithium and 17,800ppm boron for the Upper Zone.

“This upgraded Mineral Resource is exactly what we were aiming to achieve with the 2018/2019 drill program at Rhyolite Ridge,” ioneer managing director Bernard Rowe said in the company’s announcement to the Australian Securities Exchange.

“The higher confidence Measured Resource relates to the planned starter pit and due to the significantly higher grades, we can expect to see a material increase in the projected early operating cash flows.

“The total Resource has continued to grow with step-out drilling to the south where both the lithium and boron grades are some of the highest we have seen in the deposit.

“The lithium-boron mineralisation remains open to the south where it continues to be shallow and we expect further increases to the Resource with additional drilling.

“With the recent focus by the US Government on ensuring the supply of critical minerals, ioneer is well placed to become the first major domestic supplier of lithium to the American electric vehicle industry.”

The company explained that a planned starter pit is being developed as part of the Rhyolite Ridge Definitive Feasibility Study (DFS).

This starter pit will mine the Measured Resource and is expected to provide stronger cash flows in the early years of the project compared to the Preliminary Feasibility Study (PFS).

ioneer said the improved cash flows would become evident upon completion of the updated mine plan and schedule currently being undertaken as part of the DFS.

Lithium-boron (searlesite) mineralisation is the focus of the DFS as it represents the highest value material.

The low-clay and high-searlesite content of the lithium-boron mineralisation allows for a low-cost, simple processing route due to being amenable to low-cost acid leaching.