Australia's Ioneer quadruples reserves at Nevada lithium project

June 2 (Reuters) - Australia-based critical minerals miner Ioneer INR.AX said on Monday the ore reserves at its Rhyolite Ridge Lithium-Boron Project in Nevada have increased fourfold, with nearly half of the mineral resource being converted into reserves.

The ore reserve has quadrupled to 246.6 million tonnes from 60 million tonnes in 2020, the company said.

It contains 1.92 million tonnes of lithium carbonate equivalent and 7.68 million tonnes of boric acid equivalent, making it the world's largest lithium-boron reserve, Ioneer added.

"It allows Ioneer to match prevailing market conditions and blend or prioritise ore to produce a valuable boric acid co-product, whose market is uncorrelated with the project's primary lithium product," Managing Director Bernard Rowe said in a statement.

Lithium prices have plummeted more than 80% from their peak in November 2022 due to a supply surplus, forcing companies to idle mines and put projects on hold.

Ioneer plans to prioritize high-boron ore in the first 25 years of production, during a low lithium price environment, to maximize revenue from boric acid sales.

The upgrade of ore reserves comes months after Sibanye Stillwater SSWJ.J said it will not go ahead with the plans to invest in the lithium project, owing to the rare metal's plummeting prices.

Sibanye had agreed to set up the lithium joint venture with Ioneer in 2021, as part of its diversification into battery metals.

Ioneer estimates the total capital expenditure to complete the project to be $1.67 billion.