Microwaving Metal Turns Coal Into Valuable Graphite

Jan 12, 2021

The research team used a household microwave to turn coal into graphite.
Credit Consumer Reports

It is common knowledge not to put metal in the microwave, but that's exactly what researchers at the University of Wyoming are doing.

TeYu Chien, a UW associate professor in physics and astronomy, said the goal of their experiment is to turn coal into graphite. He said graphite is the dark part of a pencil. It's also good at conducting electricity and it doesn't melt easily. That makes it a very useful material for things like batteries.

Chien said his team surrounded the coal with argon and hydrogen gas instead of normal air so it wouldn't burn. They also needed something else: a fork-shaped piece of copper.

"You need a high, really high temperature," he said. "So we use a spark to achieve that. Sparks essentially are lightning, and so essentially we create lightning inside a microwave oven."

The spark, created by the copper fork, makes it hot enough to transform coal into graphite. Chien said graphite is more valuable than coal. Sources of graphite are limited, which means this technique could be very valuable in the future.

Chien also said the method is versatile.

"This method seems to have a wide variety of alternative ways of doing it," he said. "We can change the metal, the source, the environment, and those things get different results."

Chien said they are trying a similar process with plastic water bottles and different kinds of metal forks to see what other valuable materials they can create.

Have a question about this story? Please contact the reporter, Ashley Piccone, at apiccone@uwyo.edu.