calciumfluoride

Calcium fluoride (CaF2) is an inorganic compound that occurs naturally as the mineral fluorite (fluorspar). It is a white, crystalline solid at room temperature and forms cubic crystals with relatively low solubility in water. Impurities can impart a range of colors, giving specimens that are colorless or colored.

Chemically, calcium fluoride consists of calcium ions Ca2+ and fluoride ions F− in a 1:2 ratio. It has a high melting point of about 1,418 °C and a density around 3.18 g/cm3. It is sparingly soluble in water, and fluoride ions can be released when it reacts with acids such as hydrofluoric acid.

Occurrence and production: Calcium fluoride occurs in hydrothermal veins and is the primary component of the mineral fluorite, which is mined as a source of fluorine. Industrial production typically begins with processing fluorite ore to produce high-purity CaF2 for various applications. It can also be prepared synthetically, but most commercial CaF2 derives from fluorite.

Uses: The principal applications are as a flux in metallurgical processes (to remove silica) and as a source of fluoride ions in chemical manufacturing. In optics, calcium fluoride is valued for its broad spectral transmission from the far ultraviolet to the infrared, making it a common material for lenses and windows in UV, visible, and infrared instruments. In the glass and ceramic industries, it can act as a flux and fining agent.

Safety: Calcium fluoride is largely insoluble and has low acute toxicity, but fluoride ions can be hazardous in high doses. It can irritate skin and eyes, and inhalation of powder poses health risks. Proper handling, storage, and disposal are recommended.