Sustainable process design for lithium recovery from geothermal brines using chemical precipitation

Lithium demand is surging, necessitating efficient extraction methods. Geothermal brines offer a promising alternative feedstock, yet comprehensive systems-level analyses are lacking. We developed an industrial process model for a plant processing 2000 ton/h geothermal brine using chemical precipitation to produce lithium carbonate, coupled with techno-economic and life cycle assessments to evaluate process economics and environmental impacts. A novel recycling process for on-site reuse of precipitating agents is also proposed, increasing total investment cost by 23% while reducing CO 2 emissions by nearly 50% without extending the payback period. Additionally, we investigated the impact of feedstock concentration and water costs on process economics. Our findings show that low-concentration lithium brines (less than 200 mg/L) are economically viable only at high lithium carbonate selling prices. This study highlights the potential of geothermal brines as a sustainable lithium source and the benefits of integrating recycling processes to mitigate environmental concerns. • This work focuses on the critical need to extract lithium sustainably from geothermal brines. • We have found an innovative procedure that effectively decreases carbon dioxide emissions by 50%. • Our idea incorporates an on-site recycling technique, effectively reducing operational expenses. • Water costs play an important role in the process’s economic viability for low lithium concentration brine.