As direct lithium extraction (DLE) enters the stage of large-scale development, core materials such as adsorbents, ion-exchange materials, membrane materials and extractants are receiving increasing attention across the industry. In particular, for solvent extraction routes, an extractant with high lithium selectivity, fast extraction kinetics and good cycling stability is often regarded as a key factor determining the success or failure of a technology route. However, once deployed in a salt lake project, a material that can extract lithium in the laboratory does not necessarily mean that it can produce lithium reliably and consistently over the long term at the field site. For complex salt lake brines, what determines whether DLE can achieve continuous, stable and economical operation is often not a single generic extractant itself, but a complete process system built around the specific brine chemistry, together with the engineering capabilities required to translate material performance into industrial production capacity.
Salt lake brines are not standardized feedstocks. Different salt lakes vary significantly in lithium concentration and in the concentrations of magnesium, calcium, boron, sulfate and other components, while the composition of brine can also vary across different areas and seasons within the same salt lake. Even an extractant that performs exceptionally well in the laboratory may still be affected by ion competition, emulsification, entrainment and the accumulation of impurities once introduced into real brine. This is particularly true for brines with high magnesium-to-lithium ratios or high calcium or boron concentrations. The key issue is not simply whether lithium can be extracted, but whether selectivity, mass-transfer efficiency and material stability can be maintained over the long term. Therefore, a single laboratory performance metric is insufficient to fully assess its value for industrial application.
From the moment brine enters the system, industrial lithium extraction typically involves multiple stages, including pretreatment, core separation, concentration, impurity removal, purification and recycling. A problem at any stage can affect the final production volume and product quality. For example, a core separation material may offer high selectivity, but if impurities are not adequately controlled upstream, the material may rapidly lose its effectiveness; if the separation rate is slow, a larger equipment footprint will be required; and if regeneration efficiency is insufficient, water and chemical consumption may increase. Therefore, the true commercial value of DLE technology lies in the system integration of materials, brine chemistry, separation processes, equipment design and operational control. This is also where process application patents derive much of their value.
BICHEM’s technology portfolio is not limited to a single lithium extraction route. Instead, we have established a multi-technology process platform tailored to different salt lake resource conditions. Currently, our technology portfolio covers multiple stages, including brine pretreatment, membrane-based lithium extraction, adsorption-based lithium extraction, solvent extraction, electrodialysis and downstream lithium solution processing. Our process application patents also cover areas such as lithium-sodium separation, brine pretreatment, adsorbent applications, solvent extraction and dedicated separation equipment. The core value of this portfolio is not simply having more technologies, but being able to select the right combination of technologies based on the characteristics of each brine. For example, in the membrane-based lithium extraction process, BICHEM uses membrane separation to selectively separate lithium from impurity ions. According to our technical materials, the process enables continuous production, low water consumption and stable product quality, with a lithium recovery rate of over 98%.
For projects that require further improvements in selectivity or the treatment of complex brines, BICHEM has also developed coupled adsorption and membrane separation processes. By selectively capturing lithium through upstream adsorption and then using membrane separation for further concentration and purification, the process enables different separation units to leverage their respective strengths and improves overall resource utilization efficiency. In its solvent extraction route, BICHEM likewise focuses not only on the extractant itself, but on the complete process system encompassing extraction, filtration, phase separation and recycling.
For DLE companies, the number of patents alone cannot fully represent technological strength. Truly valuable patents should be capable of addressing specific challenges in industrial production. For example, how to pretreat complex brines, how to reduce the impact of impurities on core separation units, how to optimize lithium concentration and purification processes, how to minimize material losses, and how to ensure long-term system operation through equipment and process design.
From brine analysis to pretreatment and core separation, and then to concentration, purification and continuous operation, every stage needs to be optimized around actual resource conditions. BICHEM will continue to focus on process applications, promote the coordinated application of membrane separation, adsorption, ion exchange, solvent extraction and electrodialysis technologies, and continuously build up key process capabilities through patents and engineering experience. In BICHEM’s view, materials can be developed and equipment can be manufactured, but it is a process system that has been validated with real brines, operated over the long term and refined through engineering practice that ultimately forms the core of DLE technology’s transition to large-scale commercial application.
