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Researchers Announce Sustainable Metals Processing, Electrodes From Scrap Metal

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Metals are critical to virtually all of the products that form the basis of the global economy. Whether they are automobiles, electronics, or structural items, few would exist without metals. Yet the process that converts metals from raw materials to consumer products relies heavily on a variety of toxic chemicals. At the end of their useful life, disposing of metals creates problems of another kind.

New Research In Canada

sustainable chemistryResearchers at McGill University in Montreal say they have found new ways to create and reclaim metals that do away with most of those toxic chemicals. “At a time when natural deposits of metals are on the decline, there is a great deal of interest in improving the efficiency of metal refinement and recycling, but few disruptive technologies are being put forth,” says Jean-Philip Lumb, an associate professor at McGill. “That’s what makes our advance so important.”

Their approach uses organic compounds instead of chlorine and hydrochloric acid to purify germanium, a metal commonly used in electronic devices. The researchers say their techniques can be applied equally well to processing zinc, copper, manganese, and cobalt.

“Applications of green chemistry lag far behind in the area of metals,” Lumb says. “Yet metals are just as important for sustainability as any organic compound. For example, electronic devices require numerous metals to function.”

Kim Baines, a researcher at Western University in London, Ontario, has played a role in the research and says, “Currently, in order to isolate germanium from zinc, it’s a pretty nasty process.” The organic method pioneered by McGill and Western University “enables you to get germanium from zinc, without those nasty processes.”

Ramping Up For Production

Transitioning from lab experiments to commercial applications is always fraught with danger and disappointment. Next, the researchers will need to convince industry to adopt the new technology.

“There’s a tremendous amount of work that needs to be done to get from where we are now to where we need to go,” Lumb says. “But the platform works on many different kinds of metals and metal oxides, and we think that it could become a technology adopted by industry. We are looking for stakeholders with whom we can partner to move this technology forward.”

Making Low-Cost Electrodes From Scrap Metal

Researchers in China say they have found a way to make low-cost electrodes for batteries from scrap stainless steel. In particular, the rust that forms on the outside of the scrap can be transformed into electrodes that work well with potassium-ion batteries.

Grid-scale storage batteries will be critical to the renewable energy revolution. Lithium-ion batteries work fine for that purpose but cheaper is often a winner in the marketplace. “Potassium ions are just as inexpensive and readily available as sodium and potassium ion batteries would be superior from the electrical aspect,” reports Xin-Bo Zhang, a researcher at the Chinese Academy of Science.

Normally, stainless steel scrap is reclaimed by placing it in a furnace, a process that requires a lot of energy. The researchers use a series of chemical reactions instead, ending with a potassium-based, graphene-enhanced material that is flexible but has excellent capacity, discharge voltages, rate capability, and cycle stability.

The key parameter is that the electrodes are very inexpensive to manufacture compared to those normally used in lithium-ion batteries. Anything that helps lower the cost of grid storage will only accelerate the transition to renewable energy.

Author: sustainabilityoutlook