A blast furnace is a large industrial structure used to produce iron from iron ore. It operates by combining iron ore, coke (a form of carbon), and limestone, which are heated to high temperatures. The intense heat causes the iron ore to melt, separating it from impurities, and the resulting molten iron can be further processed into steel or other products. The process involves blowing hot air into the furnace, which fuels the combustion of coke and generates the necessary heat. This method has been a key part of the steelmaking industry for centuries, enabling the mass production of iron and steel for various applications.