To provide for better chemical durability, the "lime" is also added. This is calcium oxide (CaO), generally obtained from limestone. In addition, magnesium oxide (MgO) and alumina, which is aluminium oxide (Al2O3), contribute to the durability.
To increase chemical stability, "lime" is also included. This is calcium oxide (CaO), usually obtained from limestone. Additionally, magnesium oxide (MgO) and alumina, which is aluminium oxide (Al2O3), contribute to the strength.