Preparation
The vast majority of calcium carbonate used in industry is extracted by mining or quarrying. Pure calcium carbonate (e.g. for food or pharmaceutical use), can be produced from a pure quarried source (usually marble).
Alternatively, calcium carbonate is prepared by calcining crude calcium oxide. Water is added to give calcium hydroxide, and carbon dioxide is passed through this solution to precipitate the desired calcium carbonate, referred to in the industry as precipitated calcium carbonate (PCC):
- CaCO3 → CaO + CO2
- CaO + H2O → Ca(OH)2
- Ca(OH)2 + CO2 → CaCO3 + H2O
Read more about this topic: Calcium Carbonate
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