Bouge’s Equation

Bouge’s Equation :- The Bouge calculation is used to calculate the approximate properties of the four main minerals in Portland cement clinker.

Raw Material Composition:-

C_aO (lime)    - 60-67%

SiO₂ (Slica)   - 17-25%

Al₂O₃ (Alumina) – 3-8%

Fe₂O₃ (Iron Ore) – 0.5-6%(ferric oxide)

Mgo -     0.1-4%

Alkalias – 0.4-1.3%

So₃ – 1.3-3%

Complex Compounds In Clinker:-

Bouge’s Compound:-

C₃s (Alite) – 3c_aOSiO₂ – Tri Calcium Silicate.

C₂s (Blite) – 2C_aOSiO₂ – Dicalcium Silicate.

C₃A (Aluminate Phase) – 3C_aOAl₂O₃ – Tri calcium Aluminate

C₄AF (Ferrite Phase) – 4C_aO.Al₂O₃.Fe₂O₃ – Tetra Calcium Aluminoferrite

C₃s = 4.0710C_aO – 7.6024SiO₂ – 1.4297Fe₂O₃ – 6.7187Al₂O

C₂s = 8.6024SiO₂+1.0785Fe₂O₃ + 5.0683Al₂O – 3.0710C_aO

C₃A = 2.6504Al₂O₃ - 1.6920Fe₂O₃

C₄AF = 3.0432Fe₂O₃

Combined C_aO = (66.6-1.0% Free lime) = 65.6%

This is the figure we use for C_aO in the Calculation.

From the analysis, we have :-

C_aO= 65.6% , SiO₂= 21.5% , Al₂O₃ = 5.2% , Fe₂O₃ = 2.8%

The Bogue’s Calculation is therefore:-

C₃s = (4.0710*65.6)-(7.6024*21.5)-(1.4297*2.8)-(6.718*5.2)

C₂s =(8.6024*21.5)+(1.0785*2.8)+(5.0683*5.2)-(3.0710*65.6)

C₃A =(2.6504*5.2)-(1.6920*2.8)

C₄AF =3.0432*2.8

So:-

C₃s = 64.7%

C₂s = 12.9%

C₃A = 9.0%

C₄AF = 8.5%