Core & Ext. Metals: Extraction
Slide 27 of 45
Cement from Limestone
Limestone, a form of calcium carbonate (others being chalk and marble), also finds use in
–cement manufacture and
–lime production (in addition to being used in the extraction of iron)
Cement manufacture first involves heating powdered limestone with clay in kiln.
The product is then powdered and mixed with gypsum (CaSO4•2H2O).
The result is a mixture to which when water is added a complex chemical reaction produces the hard solid cement consisting of calcium aluminate (Ca(AlO2)2) and calcium silicate (CaSiO3).