Iron and Steel Slag (or Steel Slag) is a comprehensive term for the essential non-metallic byproducts from the entire ferrous metal production chain, encompassing both blast furnace slag (from pig iron production) and steelmaking slag (BOF and EAF slags).
Primarily composed of oxides, slag's fundamental purpose is metallurgical purification—it absorbs harmful impurities like sulfur and phosphorus from the molten metal. Crucially, these materials are no longer viewed as waste but are established as secondary raw materials, used extensively in civil engineering and cement production, which significantly bolsters the sustainability and circularity of the construction sector.