
242 Aluminum Recycling
Applying high-voltage power to the torch generates an electric arc between the elec-
trodes that heats the gas to plasma temperatures (>5000°C). Gases this hot give off
nearly all of their available heat by radiation, resulting in much higher thermal ef-
ciency than that of an RSF. As a result, gas usage is minimal, resulting in much lower
off-gas volumes than RSF. This reduces oxidation and results in metal recoveries
of over 95%. Again, salt-free processing yields the same advantages as previously
described. However, plasma dross processing has also not succeeded commercially.
High electricity prices and high capital costs ...