New research out of the University of New Brunswick (UNB) may make aluminum smelting more efficient and sustainable while also creating a source of green, zero-carbon fuel and supporting sectors that rely on aluminum materials. By creating a new, closed-loop, low-energy aluminum digestion process, the research takes a promising step toward decarbonizing the aluminum industry—and creating an environmentally sustainable future.

The findings are detailed in a paper authored by Barry Blight, a professor of chemistry at UNB; Mason Lawrence, an NSERC post-doctoral fellow; and graduate student Robbie Horne. The article was published in August 2025 in the journal RSC Sustainability.

Blight had been presented with a challenge: current processes for smelting aluminum (a high-temperature chemical reaction that separates the metal from its ore) leave behind a lot of waste material called dross. Could something useful be done with it?

Dross contains significant amounts of aluminum that aren’t captured by smelting as well as silicates and metals like iron, magnesium and manganese. In Canada alone, the aluminum industry generates an estimated quarter million tonnes of dross a year. Globally, dross production is estimated at 5.3 million tonnes a year.

Current methods for extracting more aluminum—or other materials—from dross are costly, requiring expensive equipment, a significant amount of energy, or both. As a result, much of this potentially valuable material is simply discarded and ends up in landfills.

However, based on the results of Blight’s new research, this could soon change.

The research suggests that dross could be used to cleanly produce trillions of litres of hydrogen gas as well as commercially valuable compounds like high-purity aluminum oxide. Aluminum oxide is used in aluminum smelting and to make products as diverse as pharmaceuticals, cosmetics, fire retardants and chemicals.

The processing of dross has also been modified to yield metal organic frameworks (MOFs), which are special, porous materials. MOFs have been a major research focus for Blight’s team and can be used to store hydrogen, capture carbon, harvest water or, in some cases, even help neutralize chemical weapons.

Dross processing works as a closed-loop catalytic system, generating valuable materials without breaking down the catalyst (the substance used to trigger the reaction). The process generates hydrogen gas and several aluminum materials sustainably and at a much lower energy cost than currently used methods.

As is often the case, this breakthrough didn’t happen spontaneously or independently.

Blight’s team had been working on new applications for the production of hydrogen gas from water through photocatalysis, a process that uses light energy to make a chemical reaction occur where it otherwise would not. Meanwhile, in UNB’s Office of Research Services, the Research and Innovation Partnerships team had become aware of an aluminum refining technique based on chemical digestion. The team brought it to Blight.

Chemical digestion breaks matter down into component molecules through exposure to certain substances, similarly to how the human body breaks down food. This aluminum technique had existed for some time, but was not fully developed or commercially viable.

Just like a successful chemistry experiment, bringing these 2 ideas together ended up creating just the reaction the researchers were hoping for.

By integrating the research and development related to this chemical digestion technique with their ongoing work, Blight’s team improved the digestion process. Their adjustments make the digestion more efficient and complete while generating clean hydrogen. The team also expanded the process to purify aluminum oxide and create MOF material.

Since then, the project has continued to pick up speed. The team has received funding for a post-doctoral fellowship and additional research, and is now identifying novel, potentially valuable intellectual property and partnering with industry to work toward commercialization and other sector needs.

“We are really excited about how this research translates to industry applications and to creating a greener future,” says Blight. “We’ve identified a sustainable, circular economy for this industrial waste, turning it into energy and useful materials. We are now exploring the use of waste and salvage aluminum as source materials for these processes, and we hope to develop a recycling site right here in New Brunswick.”

This article was adapted and published with permission from UNB.

Photo: Barry Blight