Recirculation of material back into the steelmaking processes reduces the need for virgin raw materials and lowers production costs.
SSAB’s steel production gives rise to a number of valuable residuals that can be recirculated. Out of an annual total of around 4 million tonnes of residuals from ore-based production in the Nordics, roughly half is recirculated back to SSAB’s steel production processes. As an example, the new sludge drying method which was brought into use in Luleå in 2014 results each year in 10,000-20,000 tonnes of basic oxygen steelmaking sludge being turned into briquettes for use as a raw material instead of being landfilled. In addition, ladle slag originating in the continuous casting process in Luleå is used as raw material in the blast furnace instead of being landfilled. In Raahe, desulfurization slag is utilized in internal infrastructure construction. Development work means that ladle slag is nowadays totally utilized. The metallic part is returned back to the iron and steelmaking process. Out of the non-metallic part, course fraction is returned to the blast furnaces to replace limestone. In addition to this, the remaining undersize fraction is sold as liming agent to agriculture to replace natural liming materials.