We just learned about Gangue.
Another part of smelting is something called flux.
When blacksmith has iron ore, they want to turn it into iron, and get rid of the gangue and turn it into slag.
Sometimes the only way to get rid of the gangue ore is to use another chemical called a flux.
There are a few different types of fluxes, but one that was used a lot is limestone.
When the iron ore is heated up in the blast furnace, the limestone melts and sticks to the gangue, and it all melts off and turns into slag, just leaving the iron behind.
(from: wikipedia - limestone)
Kid Facts - Blast from the past: Tornado Family
