Тетраборат кальция

Description

Calcium tetraborate (calcium borate, CaB4O7) is a calcium salt of tetraboric acid, an inorganic compound from the class of alkaline earth metal borates. Its chemical behavior is similar to sodium borates (borax): soluble in water and acids, serves as a source of boron in industrial and agricultural applications. Natural analogs are the minerals colemanite (Ca2B6O11·5H2O) and pandermite, as well as calcium borates, developed as boron ores. Technical calcium tetraborate is obtained from borate ores or synthetically - by neutralizing boric acid with calcium compounds.

Basic Attributes

• CAS No.: 12007-56-6
• Chemical formula: CaB4O7 (B4CaO7)
• Molecular weight: 195.32
• Exact weight: 197.98
• EU number: 234-511-7
• DSSTox ID: DTXSID1091555
• PSA: 107.95
• XLogP3: -2.739

Physico-chemical characteristics

• Solubility: soluble in water and acids

Toxicity

• Oral, rats, LD50: 5600 mg/kg
• Oral, mice, LD50: 5900 mg/kg

Scope of application

Calcium tetraborate, like other borates, is used as a flux in the production of glass, ceramic glazes and enamels - it reduces the temperature and viscosity of the melt, and is part of frits and glaze mixtures. Serves as a source of boron in boron fertilizers to compensate for the deficiency of this microelement in agricultural crops: boron deficiency is manifested by the death of growing points, deformation of fruits and a decrease in the yield of industrial crops. It is used as a fire retardant and fire retardant impregnation for wood and cellulose materials - when heated, borates release water of crystallization and contribute to the formation of a protective charred layer that slows down combustion. It is used as a corrosion inhibitor in coolants and process solutions, where it forms a passivating film on the metal surface.

Comparison with other borates

In solubility and chemical behavior, calcium tetraborate is inferior in prevalence to sodium borates (borax, sodium tetraborate), but wins in applications where the accumulation of sodium is undesirable - in particular, in some glass formulations and in feed and fertilizer mixtures, where calcium ions are additionally useful as a macronutrient.

Safety Information

According to the initial data, acute oral toxicity is moderate: LD50 in rats 5600 mg/kg, in mice 5900 mg/kg, which corresponds to a low acute hazard if swallowed. UN codes, transport classification and GHS H/P phrases are not indicated in the primary source. When working with the substance, you should be guided by the general requirements for inorganic borates: avoid the formation of dust, use respiratory protection, and avoid prolonged contact with skin and mucous membranes.

Storage and transportation conditions

Low temperature warehouse, ventilated and dry. The container is tightly closed - the substance, like most borates, is prone to caking at high humidity. According to the available data, no special transport restrictions have been established, however, during mass transportation of a technical product, standard requirements for bulk inorganic salts are applied.