is called secondary aluminum melting, or smelting.  Making aluminum from ore requires more than 13.5 MWh of electricity per ton. In practice, the consumption is closer to 14.5 MWh/ton.  This is because of carbon anodes, even though aluminum production is always electric (the Hall-Héroult process).

• Remelting recycled aluminum consumes only a fraction of that amount.  Theoretically, remelting from room temperature to 750 °C (its melting point is 661 °C) requires only about 0.291 MWh per ton of metal. In practice, it requires about 0.3 to 0.5 MWh/t, depending on whether the remelting is done in an electric or gas-fired furnace.  Electric furnaces are substantially more efficient.
• The carbon footprint (GHG emissions) of aluminum production is proportional to its energy consumption.
• Melting & Casting (non-electric): Emits roughly 0.5 to 1 ton of CO2 (eq) per ton of metal, driven almost entirely by the combustion radiation loss and stack discharge of natural gas in remelting furnaces.
• Melting & Casting (electric): Emits roughly 0 tons of CO2 (eq) per ton of metal.
• Additional substantial savings come from reducing dross (from oxide-hydroxide metal loss) and through electric process controls.  Fuel-fired furnaces have substantial energy losses, whereas electric furnaces have much lower dross losses.
• To put this in perspective, using an electric furnace that makes 5% less dross than a fuel-fired furnace for an annual production of 10,000 tons and assuming aluminum prices at about $3000 per ton is about one million and five hundred thousand ($1.5 million).
• Plus, the fantastic savings in energy and the savings in emissions-related costs. If the tax were just $51 per ton of CO2 emitted, the savings would be about $0.5 million annually.
• The aluminum industry generates about 1.1 billion tons of carbon dioxide emissions annually. MHI’s electric Airtorch units can reach the required temperatures instantly and, because they are efficient at all temperatures, reduce energy use while eliminating CO2 and other GHG emissions.
• Compact megawatt heating systems now available achieve over 98% energy efficiency. The return on investment is quick, especially when you factor in the cost of emitting toxic pollutants such as CO2, methane, NOx, SO2, and soot.
• One of the fastest ways to cut emissions and boost energy efficiency and productivity is by reducing friction and electrifying industrial heating with the Compact Electric Airtorch®, MightySteam®, and the  CleanElectricFlame®.  
• Using modern electric methods is very attractive.