- Ioneer Ltd announced a **material improvement in project economics** for its Rhyolite Ridge Lithium-Boron Project, including a **38% increase in unlevered life of mine NPV to US$1,888 million** and a **16% increase in unlevered life of mine IRR to 16.8%**.  **[1896084_0001140361-25-033825_ef20055057_ex99-1.htm:0]** 
- These improvements are driven by leach optimization, leading to a **20% increase in annual lithium hydroxide production** (years 3-25) to **25,500 tpa** and a **9% increase in annual boric acid production** (years 1-25) to **126,700 tpa**.  **[1896084_0001140361-25-033825_ef20055057_ex99-1.htm:0]** 
- The enhancements were achieved with **no increase in project capital costs** and **no change to process plant design**.  **[1896084_0001140361-25-033825_ef20055057_ex99-1.htm:0]** 
- The project's estimated all-in sustaining cash cost is **US$5,626 per metric tonne lithium carbonate equivalent** for the first 25 years, positioning Ioneer in the lowest cost quartile for lithium production globally.  **[1896084_0001140361-25-033825_ef20055057_ex99-1.htm:0]** **[1896084_0001140361-25-033825_ef20055057_ex99-1.htm:4]** 
- The Rhyolite Ridge Project has an **82-year mine-life** with an Ore Reserve of **260 million tonnes**.  **[1896084_0001140361-25-033825_ef20055057_ex99-1.htm:3]** **[1896084_0001140361-25-033825_ef20055057_ex99-1.htm:5]**

ioneer (IONR)