What is Slag? (with pictures) - wisegeek.com
Mar 18, 2019· Non-ferrous smelting, used to refine copper, lead, and similar metals, produces highly ferrous slag, as iron is an undesired element. Ferrous smelting, such as that used to produce steel, creates non ferrous slag, as all the iron is used in the smelting process. After slag is allowed to age, it can be sold for use in other industrial processes.