Minecraft wiki entry for Blast_Furnace, associated text: Blast furnaces are similar to furnaces, but can smelt only raw ore, ore blocks and tools/armor made of iron, gold or chainmail. Blast furnaces serve as the counterpart to smokers, which are used mainly to cook food faster. Smelting equipment yields one iron or gold nugget from their respective materials. Once an item and a fuel are placed into the blast furnace, the block state changes to lit and the item is smelted twice as fast as a regular furnace. Fuel is also used at double the rate of regular furnaces, so the number of items smelted per fuel stays the same. The product can then be collected by using the output. Like normal furnaces, a hopper can be used to feed items into a blast furnace and can also pick up items from it.