With a bit of ‘metal whispering,’ engineers have developed technology capable of recovering pure and precious metals from the alloys in our old phones and other electrical waste. All it takes is the controlled application of oxygen and relatively low levels of heat.

Using controlled applications of oxygen and relatively low temperatures, the engineers say they can dealloy a metal by slowly moving the most reactive components to the surface where they form stalagmite-like spikes of metal oxides.

That leaves the least-reactive components in a purified, liquid core surrounded by brittle metal-oxide spikes «to create a so-called ‘ship-in-a-bottle structure,’» said Martin Thuo, the leader of the research project and an associate professor of materials science and engineering at Iowa State University.

«The structure formed when the metal is molten is analogous to filled cave structures such as stalactites or stalagmites,» Thuo said. «But instead of water, we are using oxidation to create these structures.»

A paper describing the new technology, «Passivation-driven speciation, dealloying and purification,» has recently been published by the journal Materials Horizons.

University startup funds and part of a U.S. Department of Energy Small Business Innovation Research grant supported development of the technology.

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Materials provided by Iowa State University. Note: Content may be edited for style and length.