blast furnace 
noun
A smelting furnace in the form of a tower into which a blast of hot compressed air can be introduced from below. Such furnaces are used chiefly to make iron from a mixture of iron ore, coke, and limestone.The traditional method for extracting pure iron from its ore is to heat the ore in a blast furnace with limestone and coke....
- The roasting process uses oxygen in a blast furnace to convert the metal sulfide into the metal or the metal oxide plus sulfur dioxide.
- The explosion occurred when molten iron leaked from a blast furnace.