Abstract

The conventional lithium production from salt lake brines is mainly based on a linear economy approach, resulting in large quantities of waste, high reagent consumption, and significant water losses. In addition, emerging technologies based on direct lithium extraction do not fully address these issues and are mainly focused on reducing water losses and increasing lithium extraction efficiency. In this regard, this study conceptually proposes a novel process for the direct production of LiOH from chloride-based brines, overcoming a current limitation of the conventional lithium production route, including a simulation of a Li recovery case from Li/carnallite waste. This new approach, referred to as the AMeLi process, efficiently removes Mg using a recovered and recycled precipitating agent, thereby avoiding additional waste generation and minimizing reagent consumption. The process leverages the benefits of ammonia chemistry, similar to the Solvay process, and integrates different membrane separation technologies (i.e., gas-filled membrane absorption, Donnan dialysis, and membrane distillation-crystallization). Simulation results showed that this novel approach can achieve Li recoveries above 95%, with minimal freshwater consumption, a capital expenditure (Capex) intensity of approximately 4,000 USD/ton LCE, and an operating expenditure (Opex) of 1,660 USD/ton LCE, both values significantly lower than those of conventional and alternative lithium extraction technologies. Although several challenges must still be addressed in future studies to scale up the process, this innovative approach aligns with the next generation of circular hydrometallurgical technologies.