Primary Raw Material: Limestone (CaCO₃) is the key ingredient in Portland cement.
Clinker Formation: Limestone is heated in kilns to form lime (CaO), which reacts with silica and alumina to create clinker (the main component of cement).
CO₂ Emissions: The calcination process releases CO₂, but carbon capture technologies are being developed to reduce emissions.
Alternative Uses: Blended cements use carbonate-based materials (e.g., fly ash, slag) to lower emissions.
2. Metallurgy and Steelmaking
Fluxing Agent: Limestone (CaCO₃) and Dolomite (CaMg(CO₃)₂) are used as flux in iron and steelmaking.
Slag Formation: These minerals help remove impurities (silica, phosphorus, sulfur) by forming slag, which protects molten metal.
Magnesite (MgCO₃): Used in refractory linings of furnaces due to its high heat resistance.
3. Other Industrial Applications
Glass Manufacturing: Carbonates like limestone and soda ash (Na₂CO₃) are used in glass production to stabilize the melt and lower the melting point.
Chemical Industry:
Sodium carbonate (Na₂CO₃) (soda ash) is used in detergents, paper, and water treatment.
Calcium carbonate (CaCO₃) is used as a filler in plastics, paints, and pharmaceuticals.
Construction Materials: Marble (recrystallized limestone) is used for flooring, countertops, and decorative structures.
Agriculture: Ground limestone is used to neutralize acidic soils and improve crop yields.
