Slagtype

Slagtype is a term used in metallurgy to describe the various classifications of slag, the molten byproducts formed during ore smelting and metal refining. The classification typically considers both the origin of the slag and its chemical composition, which together influence its physical properties and potential uses.

Slag types by origin include blast-furnace slag (ironmaking with limestone flux), steelmaking slag (from basic oxygen or electric arc furnaces), and non-ferrous slags (from copper, lead, zinc, and other non-ferrous smelting). By chemistry, slags are often described as basic or acidic. Basic slags contain higher levels of calcium oxide (CaO) and magnesium oxide (MgO) and generally have lower acidity, while acidic slags are richer in silica (SiO2) and alumina (Al2O3) and tend to be more viscous. Neutral slags have a more balanced oxide composition.

The properties of a slagtype—such as melting temperature, viscosity, and crystallization behavior—are dictated by its composition and cooling history. These properties affect how the slag behaves in the furnace, how it can be tapped or separated from the metal, and how it solidifies upon cooling.

Applications and environmental considerations: Many slagtypes are recycled as construction materials, including aggregates for road bases and cementitious substitutes, or ground to produce supplementary cementitious material. Some slags require stabilization or containment due to potential heavy metal content or leaching concerns, and their reuse is guided by local regulations and testing.

Note: The term slagtype is not standardized worldwide; naming and definitions vary by country, industry, and processing method.