Probably not in a steel mill, because otherwise you could have just heat water to steam and use it to run a generator. Since this is not done, there is a catch.

Probably not in a steel mill, because otherwise you could have just heat water to steam and use it to run a generator. Since this is not done, there is a catch. An example where this idea works is a condensing boiler where the burned gases heat is used to increase efficiency by 10-30%.