(356d) Opportunities for Membrane Materials and Processes to Advance Sustainable Critical Mineral Separations

Sustainable energy solutions, electrification, and high-performance computing are driving increased demand for critical minerals. To meet this demand in a sustainable manner, new environmentally responsible separation processes are required. Membrane technologies, with their small footprint and modular nature, are well-positioned to address both the operational and environmental challenges associated with current mineral processing methods, thereby offering new pathways to more resilient critical mineral supply chains. However, realizing the full potential of membrane-based separations in these applications requires overcoming barriers ranging from the molecular to systems scales. Within this framework, we introduce an automated diafiltration device that significantly reduces the time and resources needed to characterize membrane transport properties. This system evaluates membrane performance across a broad range of feed compositions and, when paired with tools of data science, accelerates material and process development. The synergy between data analytics and automated experiments provides real-time insights, reducing hands-on experimental time from 50 hours to just 40 minutes while accurately distinguishing key separation mechanisms and determining membrane transport coefficients.

The ability of the system to rapidly characterize functional membranes addresses critical knowledge gaps related to the interfacial processes that govern solute–solute selectivity and the performance of membranes in complex multi-component feed streams. For example, the insights generated from this system inform the design of staged diafiltration cascades that improve solute-selective separations. In one application, this approach concentrates La³⁺ while efficiently removing monovalent ions, producing concentrated La³⁺ with a molar purity of 99% from equimolar mixtures of La³⁺ and monovalent ions (H⁺ and Na⁺). The results described in this talk demonstrate the importance of integrating advanced material development with innovative process designs. By advancing both membrane technologies and process configurations, this research provides a pathway to more efficient critical mineral processing that are needed to realize a sustainable energy future.