Calcium carbonate is an odourless chemical compound. It is a water-insoluble source of calcium. It is mainly found in rocks and is the carbonic salt of calcium.
Some of the pure calcium carbonate minerals are Calcite, Vaterite, Aragonite. Biological sources of calcium carbonate are Snail shells, Eggshells, Oyster shells etc. Mostly used as an antacid or calcium supplement. PH value is about 9.91. Its common name is limestone.
Preparation of Calcium carbonate CaCO3
Calcium carbonate is primarily mined and processed from diverse natural mineral sources. It can also be made chemically by combining quicklime (calcium oxide, CaO) with water to produce calcium hydroxide (Ca (OH)2), which is then treated with carbon dioxide to form the calcium carbonate salt.
CaO + H2O → Ca (OH)2
Ca (OH)2 + CO2 → CaCO3 + H2O
It can be prepared on a large-scale by-passing carbon dioxide gas through calcium hydroxide (otherwise called slaked lime). However, if there is an excess passing of carbon dioxide, it results in the formation of soluble calcium hydrogen-carbonate.
Ca (OH)2 + CO2→ CaCO3 + H2O
Calcium carbonate for PVC Pipe making
PVC pipe compounds typically contain varying amounts and types of calcium carbonates, paraffin waxes, and other ingredients such as stabilizers, titanium dioxide, calcium stearate, and processing aids. the effect of calcium carbonate particle size, coating, and usage level on the properties of PVC pipe depends on quality of Calcium carbonate (purity, whiteness, hardness, particle size)
Calcite is a filler, allowing to harden the plastic through the formation of a composite, and allowing to use less plastic, which is the expensive ingredient. In other words, putting calcite in the plastic leads to a cheaper material having a higher elastic modulus. Sand may have the same role, and is even harder. So, what is required is a material which is cheap, and whose modulus is higher than that of plastic. The grain size should be compatible with the process. A broad distribution of sizes will make the filler packing more compact.
Properties of Calcium carbonate CaCO3
Sodium bicarbonate Chemical formula
CaCO3
Molecular Weight/ Molar Mass
100.0869 g/mol
Density
2.71 g/cm³
Boiling Point
Decomposes at 899°C
Melting Point
825°C
Calcium Carbonate uses
It is used as a dietary supplement when the quantity of calcium in the diet is less
It is used as an antacid to relieve stomach upset, heartburn
It is used in to purify iron from iron ore
It is used in PVC pipe manufacturing
It is used in the refining of sugar
It is used in agriculture to neutralize acidic soil
It is used as scrubbing agent in household cleaning powders
It is used in the construction of buildings and roads
