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Corporate Profile

Cement Facts

History of Cement
Cement Industry in Malaysia
Manufacture of Ordinary Portland Cement
Raw Materials Preparation
Raw Materials Proportioning & Grinding
Clinker Burning
Cement Grinding
Cement Storage & Despatch
Cement Quality

 

Raw Materials Preparation

The raw materials used in the manufacture of cement are limestone, clay and iron ore, typical chemical compositions of which are given in table 5. Limestone makes up approximately 80% of the raw material requirements, composes of mainly calcium carbonate with small intrusions of magnesium carbonate. Quarrying operations are geared to minimizing the intrusions. The limestone is crushed to less than 75mm. MgO in the cement, if present in sufficient quantities will cause expansion upon hydration thus resulting in unsoundness in the concrete.

 

Typical Composition of some raw materials

 

Component SiO2 Al2O3 Fe2O3 CaO MgO SO3 K2O Na2O LOI
Limestone 2.68 0.62 0.46 51.85 1.94 0.03 0.05 0.02 42.52
Sandy clay 81.56 11.29 1.79 0.12 0.09 0.05 0.14 0.03 4.91
Clay 65.18 21.91 3.36 0.11 0.08 0.06 0.19 0.04 9.11
Iron ore 14.88 16.79 57.74 0.12 0.56 0.04 0.04 0.03 9.87
Shale 61.10 16.42 7.01 1.02 2.34 0.01 4.12 1.65 3.71
Sand 94.70 2.90 0.24 0.35 0.13 0.01 0.60 0.21 0.91
Bauxite 3.11 57.59 15.74 4.16 0.16 0.29 0.08 0.08 15.40
Gypsum 4.31 0.34 0.14 31.19 0.11 43.88 - - 19.39
Fuel Ash 57.20 17.36 9.11 3.95 1.80 3.40 0.78 2.50 -
Due to the variable nature of these three components, they are pre-blended prior to their use. Here in Tasek, limestone is crushed and stored in a covered circular storage dome, utilizing the chevron pile stacking method. In this method, stacking takes place at one end of the pile. At the other end of the pile the limestone is reclaimed and then stored in a silo. Clay and iron ore are crushed in a crusher and are then stored in a storage hall. Prior to use the two components are reclaimed and stored in intermediate silos.
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