Ioneer Quadruples Rhyolite Ridge Reserves, Extends Mine Life to 95 Years

On June 2, 2025, Ioneer Ltd. announced a 308% increase in ore reserves at its Rhyolite Ridge Lithium-Boron Project in Nevada, raising the estimate to 246.6 million tonnes. The deposit now contains 1.92 million tonnes of lithium carbonate equivalent (LCE) and 7.68 million tonnes of boric acid equivalent (BAE). This positions Rhyolite Ridge as the world’s largest known lithium-boron deposit. The update extends the mine’s life to an impressive 95 years. Annual production is expected to reach 17,200 tonnes of LCE and 60,400 tonnes of boric acid—key inputs for electric vehicles, agriculture, and pharmaceuticals. The expansion strengthens U.S. efforts to secure domestic critical mineral supplies.