Calcium is a chemical element with the symbol Ca and atomic number 20. It is a reactive metal that is abundant in the Earth's crust and is the fifth most abundant element overall. Calcium is an essential element for life and is a key component of bones, teeth, and shells.
Sources of Calcium:
Limestone: Limestone is the most common source of calcium, and it is mainly composed of calcium carbonate (CaCO3). Limestone is used in the production of cement, as a filler in paper and plastics, and as a soil conditioner.
Gypsum: Gypsum is a mineral that contains calcium sulfate (CaSO4) and is used in the production of plaster and drywall.
Minerals: Other minerals that contain calcium include dolomite (CaMg(CO3)2), ankerite (Ca(Fe,Mg)(CO3)2), and siderite (FeCO3).
Uses of Calcium:
Construction: Calcium is used in the production of cement and concrete, which are used in construction.
Food and Beverage: Calcium is an essential element for human health and is used as a fortifying agent in food and beverage products. Calcium-rich foods include dairy products, leafy greens, and nuts.
Industrial Applications: Calcium is used in the production of certain metals, as a desulfurizing agent in steel production, and in the treatment of water and sewage.
Properties of Calcium:
Physical Properties: Calcium is a soft, reactive metal that is silvery in color. It has a density of 1.55 g/cm3 and a melting point of 842°C.
Chemical Properties: Calcium is highly reactive and will ignite upon contact with water. It reacts with air to form calcium oxide (CaO) and calcium carbonate (CaCO3).
Extraction of Calcium:
Mining: Calcium is primarily obtained through the mining of limestone, which is mainly composed of calcium carbonate (CaCO3).
Electrolysis: Calcium can also be produced through the electrolysis of calcium chloride (CaCl2). In this process, CaCl2 is melted and subjected to an electric current, which causes the calcium to separate from the chloride.