Boron Oxides, Boric Acid, and Borates

Abstract

Nearly always occurring bonded to oxygen, boron is naturally present everywhere on the earth, including in rocks, soils, and natural waters. However, large borate mineral deposits are rare. Only a few of the more than 200 known borate minerals, including borax, kernite, ulexite, and colemanite, are primary sources of industrial borates. These minerals are extracted in California and Turkey, and to a lesser extent in South America, Russia and Asia. Major industrial borate products include boric acid, borax pentahydrate, borax decahydrate, anhydrous borax, and boric oxide. Beneficiated colemanite and ulexite ores are also used in some applications. Specialized industrial borates include sodium, potassium, ammonium, barium, and zinc borates. Physical properties and nomenclature systems of borates are reviewed. Borates have many industrial uses. The largest one is the manufacture of glass, including energy saving insulation fiberglass and borosilicate glasses. Other uses include the manufacture of ceramics, building products, house wares, consumer electronics, fertilizers, alloys, magnets, lubricants, and adhesives. Boron is required by all plants and is necessary for growth and fruiting. For this reason, boron fertilizers are routinely applied throughout the world where soils are deficient in order to improve crop yields. Boron at high levels can also inhibit bacteria, decay fungi, and insects, providing the basis for their use in the protection of wood‐based building products. Environmental, health, and safety aspects of borates are reviewed.

Sonochemical Synthesis of Small Boron Oxide Nanoparticles

“…Although efforts at nanostructuring metal and nonmetal oxides (e.g., TiO 2 , Fe 2 O 3 , SiO 2 , Al 2 O 3 ) have garnered much attention over the years, we were surprised at the lack of available synthetic methods for producing well-defined nanoscale B 2 O 3 systems. Bulk B 2 O 3 is a common component in oxide glasses and ceramics for large-scale industrial uses such as optical glasses, insulation fiberglass and fire retardants. , Additionally, B 2 O 3 -glasses are also used in radiation shielding , and dielectric applications . However, processing options for bulk B 2 O 3 require high temperatures for melting and sintering, as well as specialized equipment.…”

Experimental studies on viscosity, thermal and tribological properties of vegetable oil (kapok oil) with boric acid as an additive

“…The boric acid is very stable at room temperature and soluble in boiling water. When the boric acid is heated above 170 • C, the solid loses water and slowly converted into metaboric acid and on further heating, it was converted into boric oxide [30]. Eco-friendly lubricant from the class of vegetable oil (kapok oil) was premixed with 1, 3 and 5 wt% of boric acid separately mixed using a magnetic stirrer for 2 h at ambient temperature (34 • C) until the nanoparticles was evenly spread throughout the lubricant and without any solvent/surfactants.…”

Hydrated Zinc Borates and Their Industrial Use

“…Zinc borates rank in the top ten boron-containing industrial chemicals in terms of global production and use [1]. Tens of thousands of tons of zinc borates are used annually in various applications utilizing their special properties.…”