Ioneer Ltd just delivered a major update on its 100%-owned Rhyolite Ridge Lithium-Boron Project in Nevada. The company announced a huge 308% increase in Ore Reserves, along with fresh economic projections for the project.
Ioneer’s High-boron Strategy: Weathering the Weak Lithium Market
The miner revealed that the Ore Reserve has jumped by 186.6 million tonnes, bringing the total to:
- 246.6 Mt at 1,464 ppm lithium and 5,444 ppm boron,
- Containing 1.92 Mt of Lithium Carbonate Equivalent (LCE)
- And 7.68 Mt of Boric Acid Equivalent (BAE)
Nearly 48% of the Mineral Resource has now been converted into Reserve. Ioneer claims this makes Rhyolite Ridge the world’s largest known lithium-boron deposit.
The project is now expected to produce:
- 17,200 tonnes of LCE per year (life-of-mine average)
- 60,400 tonnes of boric acid per year
But for the first 25 years, the company plans to focus on high-boron ore (Hi-B), which would boost output to about 19,200 tonnes of LCE and 116,400 tonnes of boric acid annually.
Lithium’s Low-Cost Advantage Despite Market Woes
With lithium prices under pressure, Ioneer is leaning into boric acid as a stable revenue stream. Boric acid is used in everything from agriculture and construction to pharmaceuticals. For the first 25 years, it’s expected to account for about 25% of revenue.
It’s because of this boron credit, Rhyolite Ridge is now projected to sit in the lowest cost quartile for global lithium production:
- US$5,745/t all-in sustaining cost (battery-grade lithium hydroxide)
- C1 cost of US$3,858/t after boric acid revenue offsets
Capital Costs and Future Upside
Ioneer has also refined its cost estimates using detailed engineering. It now expects to spend US$1.67 billion to bring the project online, including a 10% contingency. Around 70% of engineering work is already complete.
The team has taken a more conservative stance on plant uptime and equipment maintenance, prioritizing long-term reliability over short-term gains.
Still, there’s room to grow. Recent testwork showed that reducing leach time from 3 days to 2 could boost acid yield by 7–14%, increasing lithium and boron output with minimal added costs. This faster process will be adopted once a new mine plan is ready.
Stockpiles and Stage 2 Potential
Hi-B ore will be the priority early on, which means a large amount of low-boron (Lo-B) ore will be stockpiled. This shift explains the lower life-of-mine mining cost ($9.90/t) compared to the first 25 years ($23.50/t). Much of the later production will come from these stockpiles.
Interestingly, Ioneer is exploring the option of using gravitational concentration to upgrade Lo-B ore by 1.4 to 2.0 times, potentially making it ideal for a future Stage 2 processing facility.
Rhyolite Ridge: A Key Lithium Project Powering the EV Future
Rhyolite Ridge is one of only two advanced lithium projects in the U.S. and is already fully funded up to the Final Investment Decision stage. Its valuable boron by-product and smart, cost-saving design stand out as a low-cost and sustainable operation.
Over its 26-year life, the project is expected to support battery production for more than 50 million electric vehicles. Thus, it’s all set to boost the U.S. lithium supply and will help reduce fossil fuel dependence. Overall, it supports the shift to low-carbon transport.
Furthermore, by processing materials directly on-site, Ioneer avoids the delays and costs of shipping to off-site facilities. This allows faster and more efficient production of lithium carbonate, which is a critical material for EV batteries.
Broadly speaking, Ioneer works closely with industry leaders and stakeholders who share a common vision: advancing electrification and cutting emissions.
Smart, Sustainable Operations
What sets Rhyolite Ridge apart is its world-class, environmentally focused design. The entire operation is built around sustainable practices:
- Low Water Use
Uses around 4,000 acre-feet of water each year — about the same as seven irrigation pivots. It means the mine uses very little water and recycles contact water as much as possible. - Lower Emissions
Relies on carbon-free energy and keeps greenhouse gas emissions to a minimum. Runs on a closed-loop steam system that generates green energy with zero carbon dioxide (CO₂) emissions. - It doesn’t rely on outside electricity from the grid.
- Smaller Footprint
No evaporation ponds. No tailings dam. Less impact on the environment.
Why Market Challenges Remain for Ioneer?
While the long-term vision looks strong, recent lithium price declines have made investors cautious. Earlier this year, Ioneer lost Sibanye-Stillwater as a joint venture partner, partly due to the weak pricing environment.
Despite this, Ioneer remains confident. Its strategy of front-loading boron-rich ore could provide valuable cost support, especially if lithium prices remain volatile. The company says its diversified product mix and large reserve base position Rhyolite Ridge as a top-tier global project.