ioneer will deliver up to 7,000t/y of lithium carbonate to EcoPro over a three-year term. The 7,000t/y comprises an initial and firm 2,000t/y, subject to ioneer's final investment decision (FID on the project, and an additional and optional 5,000t/y, subject to mutual agreement no later than the first quarter of 2022. 

EcoPro plans to convert ioneer's lithium carbonate into high purity lithium hydroxide at its cathode plant.

The agreement marks ioneer's first lithium offtake agreement and represents up to 34% of ioneer's annual lithium carbonate output for the first three years of production. ioneer expects to produce an annual average of approximately 20,600t/y of lithium carbonate, or approximately 22,000t of lithium hydroxide, along with approximately 174,400t tonnes of boric acid per year over the 26-year mine life.

According to ioneer, the Rhyolite Ridge lithium-boron project is the only known lithium-boron deposit in North America and one of only two known such deposits in the world. The company said that the dual production of lithium and boric acid allows ioneer to not only produce lithium in the US, but to do so at the very bottom of the global cost curve, positioning it well to benefit from an expected rapid acceleration in demand for battery materials. ioneer anticipates commencing production in late 2023.

This agreement follows the earlier signing of an initial offtake agreement and two sales and distribution agreements for boric acid production, representing 100% of offtake in year one and more than 85% of boric acid production in years two and three.

Bernard Rowe, managing director of ioneer, said: "The agreement with EcoPro marks a significant milestone for ioneer."

Anthony Kim, president at EcoPro Innovation, added: "ioneer's lithium carbonate is well suited for conversion to high purity lithium hydroxide with a minimal environmental footprint".

In February, ioneer signed a memorandum of understanding with Caterpillar to employ autonomous haulage at Rhyolite Ridge. Last week, it received an air quality permit that was a pre-requisite for further progress at the project.