C3S = 4.071 (CaO- freelime) -7.6 SiO2 -6.7 Al2O3 -1.43 Fe2O3+1.9 K2O+2.9Na2O-2.85SO3+3.05 MgO

This Formula applies when MgO in clinker is less than 2.0%.

Why all the plants are not using this formula. Basically they use only formula which contains 4 basic oxides.

Can anybody share their view on this?

best regards

Shiggavi