Cement ingredients
Cements

Mineralogically speaking, cement is made essentially from four constituents:

• Lime CaO (simplified designation "C"), rather basic;

• silica SiO₂ (simplified designation "S") ;

• Alumina Al₂O₃ (simplified designation "A");

• iron oxide Fe₂O₃ (simplified designation "F"), rather acidic.

• These four basic elements are not found in nature in the right state for the emergence of hydraulic binders. Indeed, lime CaO carbonates easily by absorbing carbon dioxide from the air, to become limestone rock, in abundance in nature. The three oxides (SiO₂, Al₂O₃, Fe₂O₃) abound in nature in stable, crystallized form (sand, clays, etc.). They must therefore undergo appropriate treatment to bring...