The basics of slag...

More than 400 million tonnes of iron and steel slag is produced each year.

Global Slag Conference exist to promote the use of slag (as opposed to burying it in a hole in the ground), and to bring together interested parties, such as slag producers, slag users and slag equipment producers.

The very many forms of slag produced in world vary in value and utility, depending on their chemistry, mineralogy and physical characteristics. Air-cooled iron and steel slags, and granulated blast furnace slags, can be viewed as valuable co-products, which potentially have relatively high value and utility.

Above: molten blast-furnace slag (BFS) being poured into a pit to allow it to air-cool. It will eventually be dug-up, and may be crushed and used as an aggregate. The pot is mounted on a train, is around 3m in height, and may weigh 50t. The pour of the pot is controlled by remote control - slag is HOT and it pours just like water!

Slag can also be granulated (Granulated Blast Furnace Slag, GBFS) to form a sand-like material, which can then be ground-up (Ground Granulated Blast Furnace Slag, GGBFS) and used in cement manufacture. GGBFS is a high-specification and relatively high-value material.