Lithium is an essential raw material for modern energy systems. Demand continues to grow as electric mobility and stationary energy storage expand across the globe. Although salt lake brines represent one of the world’s most abundant lithium resources, transforming these brines into battery‑grade lithium remains one of the most complex tasks in hydrometallurgy.
Salt lake brines contain lithium in very low concentrations, typically far below the levels found in hard‑rock deposits. At the same time, these brines include large amounts of magnesium, sodium, potassium and calcium. Among these, magnesium is the most challenging to separate because it often appears at much higher concentrations than lithium. A high magnesium‑to‑lithium ratio makes selective extraction difficult and forces producers to rely on lengthy or chemical‑intensive processes.
Producing high‑purity lithium compounds requires extremely effective separation. Battery applications are sensitive to even small variations in purity, as impurities can influence battery stability, performance and cycle life. This is further complicated by the natural variability of metal concentrations in the brines. Seasonal changes, rainfall and geological factors can alter the chemical composition throughout the year, requiring processes that remain stable under fluctuating conditions.
Environmental and operational factors add further complexity. Traditional brine extraction has relied heavily on evaporation ponds, which demand large areas of land and lead to significant water loss. Many Salt Lake regions are environmentally sensitive, and producers face increasing pressure to minimize emissions, reduce energy consumption and meet stronger ESG expectations. Achieving this while maintaining reliable production can be difficult with established process routes.
The economic dimension is equally important. The lithium market is highly dynamic, yet many conventional extraction methods require large footprints, high chemical inventories and long implementation timelines. These factors can increase investment risk and make it difficult for producers to expand capacity when demand rises. As a result, many promising brine resources around the world remain underutilized or economically challenging to develop.
The combination of chemical complexity, environmental constraints and economic uncertainty has turned Salt Lake extraction into a major bottleneck for the global lithium supply chain. Addressing these challenges requires technologies that are selective, efficient, environmentally responsible and suitable for industrial scale‑up.
To overcome the limitations of existing lithium extraction processes, Sulzer Chemtech has collaborated with the Qinghai Institute of Salt Lakes (ISL), Chinese Academy of Sciences, a world leader in brine chemistry research. Together, the partnership merges advanced scientific understanding with global engineering expertise to offer a new pathway for sustainable lithium production.
At the center of this collaboration is OptimEXT, Sulzer’s advanced extraction solution designed specifically for challenging brine systems.
OptimEXT has been engineered to deal with high Mg/Li ratios and fluctuating brine compositions enabling:
This helps turn previously uneconomical brine deposits into viable resources.
OptimEXT technology offers significant economic and environmental benefits:
These factors directly address the financial and environmental pain points facing today’s lithium producers.
The modular system design allows producers to scale output in line with market demand, lowering risks associated with price volatility. OptimEXT’s operating stability and ease of use reduce downtime, maintenance needs, and long-term operational uncertainty.
Sulzer and ISL provide end-to-end support, from laboratory verification and pilot testing to full industrial deployment. This reduces project risk and accelerates time-to-market — critical advantages in a fast-moving industry.
The global shift toward electrification depends on reliable access to high‑quality lithium. The challenges associated with salt lake extraction require solutions that combine scientific understanding with practical industrial design. Through the OptimEXT solution, Sulzer aims to support the industry in producing lithium more efficiently, more sustainably and with greater long‑term stability.
Learn more about Sulzer OptimEXT™ here.