- Selective mining.
The main objectives of the mining operations are to supply the desired quality stone to the plant and to external customers, to maintain exposed reserves and ensure optimised mining sequences.
- Limestone screening.
The limestone screening process produces graded limestone and dolomite stockpiles for:
- Limestone calcination.
The calcination of limestone takes place in coal fired rotary kilns with Neims vertical coolers. Unslaked lime is calcium oxide (CaO) and is obtained by calcining (applying heat to drive off CO2) limestone (CaCO3). The following reaction takes place in the calcination process: CaCO3 + Heat CaO + CO2.
Different applications require specific unslaked lime sizing. The calcined lime from the rotary kilns is screened to specific user requirements.
- Fine grinding of unslaked lime.
The finer material from final product screening is milled to supply ground unslaked lime as well as fine ground unslaked lime.
Hydrated lime (or slaked lime) is calcium hydroxide Ca(OH)2 and it is manufactured by reacting unslaked lime (CaO) with water according to the formula: CaO + H2O Ca(OH)2 + heat.