Mike works in the metals industry. which type of coal should he use as a fuel source?

He must use charcoal.

Explanation:

Charcoal is a product obtained through the carbonization of biomass from wood. Burning results in a black substance used as an energy source. Charcoal is little used worldwide, with the exception of Brazil, which is the largest producer in the world. It is used in industry, especially in steel and metallurgy and is a great option for Mike, who works with metal.

Bituminous coal because it is known as industry coal in india as it is found on a large scale.