Moulding sand

Low-expansion Rådasand

Rådasand is used widely as uniform sand in iron and aluminium casting industries. Thanks to its mineralogical composition (50% quartz, 50% feldspar), their characteristics are combined. Quartz has a high sintering temperature (melting point) and large thermal expansion coefficient, and feldspar has a lower sintering temperature and a lower expansion coefficient. Compared to ordinary quartz sand, this is a major advantage in sand shaped constructions since it is important for the sand core to expand as little as possible and yet not melt when heated or in contact with e.g. melted cast iron.

This property minimizes the risk of the occurrence of veining defects during casting, which in turn lessens the need for polishing and cassation at foundries. Besides the minerals mentioned above, the Rådasand also contains a low sludge and moisture content and has a delivery temperature of approximately 30-40 degrees, which also helps lower adaptation costs. Consequently, the low-expansion Rådasand has a great advantage in precision casting, which places just as stringent demands on high quality as the casting of cores.

Swedish truck manufacturers use large volumes of Rådasand for casting their truck engines with good results. Thanks to its properties, the sand is also exported to foundries in Germany, France, the UK, Norway and Denmark.