Researchers at the University of Maine have developed a new method to recover high-value metals, including copper and aluminum, from contaminated powder mixtures. This breakthrough could strengthen the country’s “Made in USA” manufacturing goals.
These high-value materials are used to make precision-engineered parts, such as biomedical implants, aircraft components, battery materials, and cutting tools. Recognizing that material loss is a major challenge across critical sectors, the Maine researchers set out to address the issue.
“We’re trying to solve a significant materials-loss problem that occurs during the production of high-value components and products across critical sectors, such as aerospace, energy storage, tooling, biomedical devices and electronics,” said Bashir Khoda, lead researcher and associate professor of mechanical engineering.
He noted that the new procedure could make manufacturing more robust by helping address uncertainty in the supply chain for critical minerals, which affects cost, availability and production resilience.
Spin to separate
In the study, researchers focused on recovering metals from powder mixtures that are often discarded because of cross-contamination during handling processes.
Using a new method called shear-assisted particle entrapment (SHAPE), researchers mixed two critical metals in a liquid suspension. They placed the mixture in a spinning machine at variable speeds to separate the individual particles. The team then captured the isolated particles on a thin polymer film.
During the experiments, the team tested aluminum and copper microparticles ranging from 0 to 25 micrometers in diameter. The team suspended the particle mixture in a liquid and exposed it to rotational speeds ranging from 200 to 1,500 revolutions per minute (rpm).
At approximately 200 rpm, about 87 percent of the particles captured on the substrate were the lighter material, aluminum. As the rotational speed increased to 1,500 rpm, the dominant population shifted, with copper accounting for about 90 percent of the entrapped particles.
The researchers said that by fine-tuning the process parameters, they could selectively capture different particles.
Selective capture, low yields
Although the laboratory demonstration achieved high particle-level selectivity, the yields recovered from the starting material remained very low.
“The current study demonstrates the selectivity of the mechanism, rather than an industrially ready recovery process,” Khoda said. “The next challenge is to maintain this selectivity while substantially increasing the amount of material that can be processed and recovered.”
Future work will examine substrate size and geometry, the use of multiple substrates, particle loading, polymer concentration, processing time, and continuous or multistage operation to increase the amount of material processed while maintaining selective separation.
The team also plans to evaluate whether the recovered powders possess the properties required for reuse by examining their chemistry, morphology, flowability, and manufacturing performance.
In the long term, the researchers aim to automate the process by integrating it with artificial intelligence.
“Our longer-term objective is not simply to separate particles in the laboratory, but to develop a scalable and AI-driven manufacturing system that could recover cross-contaminated powders and return usable material to the additive manufacturing supply chain and beyond,” Khoda said.
The findings were published in Powder Technology.