Critical minerals and materials (CMMs) are commonly found in complex mixtures of elements. Traditional approaches to CMM extractions have focused on sources where CMMs are found in higher concentrations or are easier to separate and recover. However, as demand for CMMs continues to increase, new cost-effective approaches will be needed to recover CMMs from a broader range of domestic feedstocks, including those with lower concentrations and more complex compositions, to help meet growing demand and strengthen domestic supply chains. 

Researchers at Pacific Northwest National Laboratory (PNNL) are developing novel, effective ways to extract, separate, and recover CMMs from conventional and emerging alternative feedstock sources. These sources range from industrial waste to seawater and require expertise in areas such as separations science, biotic-abiotic interactions, sensing technologies, and bioengineering.

Physical and chemical separations

Physical and chemical separations have been the historical industrial standard for everything from isolating metals to pharmaceuticals. However, many traditional separations processes are highly energy-intensive and inefficient, particularly for separating materials with similar properties or materials present in low concentrations—challenges commonly found in CMM separations.

PNNL researchers are exploring new and innovative approaches to separations for CMMs. Through the Non-Equilibrium Transport Driven Separations (NETS) Initiative, PNNL scientists are exploiting far-from-equilibrium conditions, including magnetic fields and flow fields, to separate CMMs from unconventional feedstocks at laboratory scales and beyond. Researchers are leveraging advances in autonomous science to move from initial testing to separation processes in days instead of weeks or months.

Seawater is a promising source of a wide range of minerals, but the dilute concentrations pose major challenges. PNNL researchers are working on modular approaches that maximize the resources recovered from seawater, pulling multiple valuable commodities either simultaneously or in sequential steps.

PNNL is also playing a role in scaling CMM separations from the lab to industry. Through the Minerals to Materials Supply Chain Research Facility (METALLIC) program, PNNL is helping accelerate the establishment of new, domestic CMM supply chains. PNNL’s work in METALLIC includes configurable monitoring systems and separations at scale, where staff at PNNL can help design separations processes with industrial partners.

Biological separations

An exciting approach to recovering CMMs is leveraging biology to concentrate, separate, and store these elements. Researchers are exploring ways to engineer both microbes and proteins to increase their ability to bind and release specific CMMs, testing new design principles that can be extended across systems. This research can be accelerated through automated and high-throughput research platforms, including new autonomous phenotyping capabilities such as the Anaerobic Microbial Phenotyping Platform, that help researchers rapidly link biological traits with CMM extraction.

At PNNL-Sequim, researchers are studying how seaweed and microalgae accumulate CMMs from aquatic sources as well as how to extract the accumulated CMMs. Determining which specific species and strains have the greatest ability to accumulate and release CMMs will enable further selection for resilience and other desirable traits.