Slag facts for kids
Slag is a liquid residue from making iron. It consists of calcium silicate. The silicon dioxide in iron has to be taken away. The calcium oxide reacts with the silicon dioxide solid to make liquid calcium silicate, which is lighter than iron. It is drained out of the blast furnace. Slag can be used to make concrete. Air can be blown through molten slag to make a fluffy insulation made mineral wool.
Concrete made with blast furnace slag is almost pure white compared to ordinary concrete which is greyish.
Images for kids
Early slag from Denmark, c. 200-500 CE
A path through a slag heap in Clarkdale, Arizona, showing the striations from the rusting corrugated sheets retaining it.
Slag run-off from one of the open hearth furnaces of a steel mill, Republic Steel, Youngstown, Ohio, November 1941. Slag is drawn off the furnace just before the molten steel is poured into ladles for ingotting.
Slag Facts for Kids. Kiddle Encyclopedia.