This serves as a protective layer to prevent the aluminum
from oxidizing [3]. For every of liquid
aluminum, an average of 15 to 25 kg of aluminum
dross is produced [1]. Primary aluminum dross
contains approximately 80% aluminum, and secondary
one only approximately 5 to 10%. Although primary
dross can be recycled, secondary dross is frequently
disposed at landfill sites [4]. Secondary dross contains
various compounds in addition to aluminum. The
commonly found compounds, and their respective
content and weight percentages, are as follows: Al O 2 3
at 50 to 65%; aluminum nitride (AlN) 15 to 30%; Al 3
to 5%, MgO 5 to 10%; SiO 1 to 2%; CaF < 2%; and 2 2
other trace salts such as AlP and Al S [5,6]