Slag is a crucial non-metallic byproduct in metallurgical processes, such as iron and steelmaking, fundamentally governing process chemistry and refining.

Slag is essentially a molten mixture of various metal oxides, often derived from the fluxing agents (e.g., limestone) and non-metallic impurities (e.g., silica, alumina) separated from the metal bath.

Its primary functions are impurity removal and metal protection. The precise chemical composition and viscosity of the slag are meticulously controlled to ensure optimal refining and efficient separation from the primary metallic product.

Slag also finds extensive secondary use in the construction industry as aggregates, road base, and in cement production, underscoring its role in promoting material circularity.