The raw material for Hyttsand (GBS) is blast furnace slag
. With quick cooling in water the melted blast furnace slag becomes granular, a light glass sand-like proudct, which is called Hyttsand. Hyttsand with its glassy structure has other properties compared to the air-cooled slag (Hyttsten).
Hyttsand's most interesting property is its so-called latent hydraulic properties, which mean that after grinding and activating e.g. with calcium oxide it hardens just like cement.
Hyttsand's basic use.
Road construction: where the ground needs a light and strong base. Raw material for the cement industry. Raw material for Merit 5000 (GGBS).
Blast furnace slag has been used in cement over a long period of time. 1862 it was first discovered that amphorous blast furnace slag had cementing properties and a few years later manfuacture of cement based on the slag started in Germany. This type of cement is internationally known as GGBS (Ground Granulated Blast Furnace slag). Today approximately 100 million tons of GGBS is manufactured in the world. In Sweden approximately 1 million tons per annum is used.
For environmental information see: leaching of moraine.