Slag facts for kids
Slag is a leftover material that forms when metals like iron are made. It's a liquid that floats on top of the melted metal, much like oil floats on water. Slag is mostly made of a substance called calcium silicate.
When iron is made in a blast furnace, there are unwanted materials, especially silicon dioxide. To get rid of this, calcium oxide is added. These two chemicals react together to form liquid calcium silicate, which is the slag. Because slag is lighter than the melted iron, it can be easily drained away from the furnace.
What is Slag Used For?
Slag is not just waste; it's a useful material! It can be used in many ways, especially in building and construction.
Slag in Concrete
One of the main uses for slag is in making concrete. When slag is added to concrete, it can make the concrete almost pure white. This is different from regular concrete, which usually looks grey. This special concrete is often used for its unique appearance.
Slag for Insulation
Another cool use for slag is making insulation. If air is blown through hot, melted slag, it turns into a fluffy material called mineral wool. This mineral wool is excellent for keeping heat in or out, making it useful for insulating buildings.
More Images
-
Global production of iron and steel, 1942- 2018, according to USGS.
-
Pile of steelmaking slag at the ArcelorMittal Indiana Harbor steelmaking facility.
-
The Manufacture of Iron – Carting Away the Scoriæ (slag), an 1873 wood engraving
-
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.
See also
In Spanish: Escoria (metalurgia) para niños
