hot dross processing / chlorine-filled gas bubbles / aluminum beverage cans / metal / plastics / heavy media separation hydrometallurgical process / heavy media / waste products / secondary aluminum processing industry / oxidation products / nonreactive gas / manufacturing operations / thermal energy / rubber / metal-treating process steps / paint / auxiliary equipment / oil / low density metal / Chlorine gas / high density metal / heavy media separation / beverage cans / batch processing / energy / /