what is aluminum dross? and the usage of it?

Question

i am not familiar of this , i want to know about it?

Answer 1

it is the non silver stuff at the top of molten aluminum when casting and is any impurities in the melt and oxidized aluminum. Normally a chemical is added while melting to take out air from the melt and to protect the surface and the mess is pushed aside or scraped off to pour.
Other than protecting the hot melt from air, it has no use.