SLAG

Foundries themselves are already very active in recycling, using steel and cast iron scrap as their main raw materials. In the melting process a product is added to the melting metal, which sets off a reaction that brings the undesirable elements, or slag, to the top of the liquid. The slag is simply removed, left to cool down, and sent for recycling.

Treatment

The treatment is more or less identical
to that which is used for sand. All
metals and other debris are removed
and the larger pieces are crushed.