Homemade Aluminium Smelting Furnace

Aluminum smelting involves extracting aluminum from its ore, alumina or aluminum oxide (Al2O3). You can build a small aluminum smelting furnace from a sheet metal can, 12 inches or so in diameter. You also need to create a cylinder of sheet metal that fits inside the can, leaving a gap of not less than 2 inches.

Construction

Drill and enlarge (ream) two ¾-inch holes on opposite sides of the can and the cylinder and arrange the cylinder inside the can so the holes align. Insert an 18-inch length of 3/8-inch copper pipe through the holes.

Lining

Coat the inside of the furnace with a mixture of pulverized firebrick and temperature-resistant cement or fire clay, known as ganister. Similarly, pack the space between the inner cylinder and the can with ganister reinforced with wire or old hacksaw blades. Leave the lining to dry overnight, remove the inner cylinder and leave the lining to cure for 72 hours.

Burners

Install two gas burners in the bottom of the furnace and supply them with air and gas. Use ½-inch pipe for air and ¾-inch copper tubing for gas, but connect the supplies midway between the burners to equalize the pressure.

References

• Green-Trust.org: Gas-fired Smelting Furnace
• Alcoa: Aluminum Smelting