metalslag

Metalslag is a byproduct of metallurgical processes in which impurities are separated from molten metal. It forms when fluxes and gangue minerals combine with molten metal and are separated as a non-metallic layer or dispersed droplets. Slag can be glassy or crystalline in texture, and its composition varies with the ore and processing route. Typical constituents include silica, alumina, lime, and magnesia, with oxides and sulfides of trace metals that may be recovered in some cases.

Common slag types include blast-furnace slag from ironmaking; steelmaking slag from basic oxygen furnace or electric arc furnace operations; and non-ferrous slags from copper, lead, or zinc smelting. Slag textures range from air-cooled crystalline to granulated (rapidly quenched) and foamy slags produced under different process conditions.

Applications and recycling: Granulated blast-furnace slag is marketed as a supplementary cementitious material and can improve concrete performance. Ground slag can replace clinker or act as aggregate in road bases and decorative or lightweight aggregates. Slag processing can recover residual metals or minerals; some slag is used for mineral wool insulation or other industrial products.

Environmental aspects: Slag generally represents a stable waste when properly managed, but leaching of trace metals can occur if containment is inadequate. Modern slag management emphasizes recycling, stabilization, and safe disposal to minimize environmental impact and conserve raw materials.