The Smeltery is a multi block structure, similar to the Enhanced Crafting Table. To create it, please a dispenser facing upwards and two nether bricks to either side. Place the nether brick fence on top of the dispenser. Finally, light a fire under the dispenser using a flint and steel. Optionally, you can place a piece of Netherrack under the fire to keep it burning longer.
Using the Smeltery is rather simple. Let’s use the recipe for an Aluminum Ingot as an example. Start by placing an Aluminum Dust into the dispenser.
Then ensure there is a fire underneath the dispenser. and right click on the Nether Brick Fence. This will convert the Aluminum Dust into an Aluminum Ingot