Tetraborates

Tetraborates refer to a class of boron-oxygen compounds that contain the tetraborate anion B4O7^2- or related polyborate structures. They are typically found as salts of alkali or alkaline-earth metals, and the best-known example is borax, Na2B4O7·10H2O.

In solid form tetraborates consist of four boron atoms linked by shared oxygens into a compact anion, which in solution forms a mixture of polyborate species depending on pH. The tetraborate unit arises from condensation of boric acid units; in solution boron-oxygen networks shift with pH and concentration, and salts are usually hydrated. The chemistry of tetraborates is governed by the equilibrium among various boron-oxygen clusters, and many salts form hydrates with significant water of crystallization.

Natural tetraborates occur in minerals and as industrially produced salts. The most widely known is borax (sodium tetraborate decahydrate). Industrial production typically proceeds by reacting boric acid with sodium or other bases and controlled dehydration to give Na2B4O7·10H2O or anhydrous salts. The ability to form diverse hydrated and anhydrous forms makes tetraborates versatile in processing.

Applications include use as buffering and fluxing agents in detergents, as a key ingredient in glass, ceramics and enamel production, and as flame retardants and corrosion inhibitors in some metalworking contexts. They are also employed in various chemical syntheses and as hydrated salts for moisture control and mineral supplementation in some specialty processes.

Safety and handling: tetraborates generally pose low acute toxicity but can irritate skin, eyes, and the respiratory tract in dust form; swallowed quantities can cause GI distress. They should be stored in dry conditions and handled with standard inorganic chemical hygiene.