Barium fluoride

Description

Barium fluoride appears as colourless, odourless crystals/white powder and is slightly soluble in water but soluble in ethanol and methanol. When heated, barium fluoride decomposes and emits toxic fumes of fluorine and barium. Barium fluoride is used as a preopacifying agent and in enamel and glazing frits production. Its other use is in the production of welding agents (an additive to some fluxes, a component of coatings for welding rods and in welding powders). It is also used in metallurgy as a molten bath for refining aluminium.

Chemical properties

Barium fluoride, BaF2, is a white crystal or powder.Under the microscope crystals may be clear and colorless. Barium fluoride is used commercially in combination with other fluorides for arc welding (qv) electrode fluxes.

Physical properties

Barium fluoride (BaF2), also known as barium(II) fluoride, is a solid which can also be a transparent crystal. Its molecular weight is 175.34 g/mol. It occurs in nature as the mineral “Frankdicksonite”. It occurs as a white powder with a melting point of 1290 and a boiling point of 2259°C. It is slightly soluble in water (0.159 at 0.0°C and 0.162 g/100 ml of water at 20°C). The solid generally assumes the fluorite structure, but when subjected to high pressure, changes to the PbCl2 structure. In the vapor phase, the BaF2 molecule is nonlinear with an F–Ba–F angle of approximately 108°C.

The Uses of Barium fluoride

Barium Fluoride is used in ceramic flux, carbon brushes for electrical equipment, glass making, in the manufacture of other fluorides, crystals for spectroscopy, electronics and dry-film lubricants. Barium Fluoride is used in spectroscopic components. Barium Fluoride is often suitable for applications in the passive IR band (8 to 14 ?m) and is often used as a viewport window for thermography.

The Uses of Barium fluoride

As a flux and opacifier in vitreous enamels; in the manufacture of carbon brushes for DC motors and generators; in heat-treating metals; in embalming; in glass manufacture.

Production Methods

A single crystal of Barium fluoride is grown from the melt solution by the Kyropoulos method and the Stockbarger method.

What are the applications of Application

Barium fluoride is used as the transmission window in λ: 150 nm–10 mm and as the Reststrahlen filter in λ: 30–60 mm.

Flammability and Explosibility

Non flammable

Safety Profile

A poison by ingestion and intraperitoneal routes. Moderately toxic by subcutaneous route. An experimental teratogen. See also FLUORIDES and BARIUM COMPOUNDS (soluble). When heated to decomposition it emits toxic fumes of F-.

Solubility in water

Barium fluoride is soluble in water with the solubility of 0.17 g/100 g H₂O (10 ℃). It is also soluble in acid and ammonium chloride.

Purification Methods

Wash it well with distilled H2O and dry it in a vacuum. Its solubility in H2O is 1.6g (10o), 1.6g (20o) and 1.62g (30o) per L, and is soluble in mineral acids and aqueous NH4Cl. It may be stored in glass bottles. [Kwasnik in Handbook of Preparative Inorganic Chemistry (Ed. Brauer) Academic Press Vol I p 234 1963.]

Structure and conformation

The space lattice of Barium fluoride (BaF2) belongs to the cubic system, and its calcium fluoride structure has a lattice constant of a=0.6187 nm and Ba–F=0.268 nm.