DARPA has selected multiple teams of university researchers for the Recycling at the Point of Disposal (RPOD) program. RPOD will evaluate the technical feasibility of recovering multiple low-volume fraction critical elements present in end-of-life electronics hardware (e-waste). The program seeks to develop small-footprint platforms with greatly reduced energy consumption and waste generation in the extraction process.

The teams will develop novel extraction chemistries and explore practical limits of yield, extraction efficiency, and purity to recover a selective list of critical elements from a feedstock representative of commercial and Department of Defense (DoD) e-waste. The technology for both separation and coextraction of critical elements will ultimately be demonstrated in a benchtop hardware prototype.

Contemporary techniques for the recovery of materials from e-waste have been built around extracting one or two elements. The elements identified as critical due to vulnerabilities in their supply chain are typically at a very small volume fraction—approximately 0.1% - 5%—and contemporary techniques are ill-suited for their recovery.

RPOD will evaluate the feasibility of extracting up to seven low-volume fraction elements that would otherwise be lost as process waste in contemporary recovery techniques. RPOD performer teams are evaluating orthogonal approaches that have the potential to extract critical elements at a fraction of the energy compared to today’s techniques without the generation of toxic liquid or gaseous byproducts. We are looking forward to working with the performers and the Defense Logistics Agency to develop practically viable extraction technologies for DoD’s use.

—Vishnu Sundaresan, RPOD program manager in DARPA’s Defense Sciences Office

The selected teams include Arizona State University, Iowa State University, and Massachusetts Institute of Technology with the following approaches:

• Arizona State University, teamed with TG Companies LLC, will develop an improved hydrometallurgical process based on a combination of selective leaching and electrowinning. Using a regenerative process, their approach aims to reduce the number of chemicals and associated waste that results from traditional processes.

• Iowa State University will develop an innovative surface and interface engineering approach for driving alloy de-mixing to recover target materials of interest.

• Massachusetts Institute of Technology will utilize selectivity and specificity of forming sulfides from a mixture of elements. Using electrochemical reduction, they aim to recover high-purity, critical materials.

In addition to the above university teams, the National Institute of Standards and Technology will explore the feasibility of acoustic-electric force balance for a novel metrology technique and explore the applicability of this metrology technique for recovery of multiple critical elements.

The teams will first model their novel recovery technology concepts and process models to understand and define practical limits of yield as well as develop databases of supply chain webs (i.e., networks of recycling and manufacturing processes that can reuse co-extracted materials without separating them). At the end of the program, the teams will demonstrate proof-of-concept hardware for recovery of critical elements and estimate the associated energy budget to understand the feasibility of fielding this type of technology.

If successful, the recovered stream from e-waste demonstrated by the technologies developed in RPOD can be scaled up to address supply chain disruptions of critical elements sourced or processed abroad that are essential for high-performance DoD hardware.