Check out the latest in our video series where Dr. Erin Bobicki answers the most frequently encountered questions about microwaves and how they can help the mining industry. Full transcript below.

Q: What happens when you microwave rocks?

Dr. Erin Bobicki: One of the cool things about microwave treatment of ores is that it’s typically the valuable minerals that heat with the gangue being microwave transparent. It depends on the rock. Some rocks, like those made of silica, are microwave transparent. And so the microwaves will pass through and nothing will happen.

For other materials that are highly magnetic, the material is too conductive and microwaves will be reflected. However, materials with semi-conducting properties, such as sulfides and different metal oxides, heat very well in response to microwaves. Because ores are typically composed of different phases with different microwave properties, some phases heat while others do not.

And one of the cool things about microwave treatment of ores is that it’s typically the valuable minerals that heat with the gangue being microwave transparent, and this results in differential heating between mineral phases and thermal stress and fracture across the grain boundaries of the valuable mineral phases. And the end result is then improved mineral liberation after grinding.

Want to speak to one of our metallurgical engineers about the microwave mineral testing at Sepro Labs? Contact us here.