Calcium carbonate (chalk) – Feed material
Calcium carbonate has a chemical formula CaCO3. It is found in large quantities around the world in the form of rocks, and it is the building material for the shells of various aquatic animals, snails and eggs . At a temperature of 900-1000 degrees Celsius , the calcium carbonate is decomposed to carbon dioxide and calcium oxide . The process is reversible and endothermic . The method is based on the manufacture of quicklime ( calcium oxide) . Reduction of calcium oxide with carbon by heating, gives a carbide. CaCO3 – Calcium carbonate [/ dt_quote ]
Large deposits of calcium carbonate are formed where there are or have had major water basins ( lakes , seas , oceans ) . Due to its low solubility, it precipitates earlier than the most other minerals in the water basin.
Calcium carbonate treated at appropriate shape and size, is widely used as a cladding material for buildings, sculptures , monuments , and more. Calcium carbonate is used as a fertilizer in agriculture , in acidic soils , since neutralized acids ( with the formation of carbon dioxide and the corresponding calcium salt ) .