Limestone probably has the largest number of commercial applications of all the industrial minerals. These include construction (aggregate, rail ballast and dimension stone), mineral fillers (in paper, paint, plastic, rubber and pharmaceuticals), adhesives, abrasives, fertilisers, food additives, environmental applications (acidity neutralisation, flue gas desulphurisation, soil conditioning and stabilisation), and production of cement, lime and calcium chemicals.
‘High purity’ limestone is defined as carbonate rock that contains greater than 97% calcium carbonate (CaCO3, usually as calcite). It is often referred to as high-calcium, highly-calcitic or industrial limestone. Its suitability as a high purity industrial mineral (sold as calcium carbonate) is defined by the intended applications, as outlined in specification agreements between producers and consumers.
These applications define the required chemical properties (such as lime, silica, magnesia and iron contents), the physical properties (such as particle size distribution, colour and surface area) and the mechanical properties (such as strength, abrasiveness...