Iron blast furnaces using charcoal go back thousands of years. But hot blast furnaces using coal are much more recent, and the development of a coal fuelled ho

Iron blast furnaces using charcoal go back thousands of years. But hot blast furnaces using coal are much more recent, and the development of a coal fuelled hot blast furnace that could mass produce pig iron without relying on wood, followed by the Bessemer process to mass produce steel from pig iron was crucial to the Industrial Revolution. https://en.wikipedia.org/wiki/Hot_blast https://en.wikipedia.org/wiki/Hot_blast https://en.wikipedia.org/wiki/Bessemer_process https://en.wikipedia.org/wiki/Bessemer_process