Boric Acid Overview

Boric Acid - Overview

Boric acid also known as orthydrogen boratehoboric acid and boracic acid is a chemical compound with formula B(OH)3. The physical properties of boric acid is colorless and has a transparent triclinic crystal structure or white granule or powder.

Boric acid is popularly used among fire jugglers and fire spinners dissolved in methanol to give a deep green flame.It is also used in India and across the world to dust down Carrom boards to decrease friction and increase speed of play. It is used in pyrotechnics to prevent the amide-forming reaction between aluminum and nitrates. A small amount of boric acid is added to the composition to neutralize alkaline amides that can react with the aluminum.

Manufacturing Process

Acidification with sulfuric acid or hydrochloric acid

Boric acid is produced from borax, colemanite, or other inorganic borates by reacting it with sulfuric acid or hydrochloric acid. After the reaction is performed, the product/solution is cooled to proper temperature. The reaction is shown below:

Na2B4O7.10H2O + H2SO4 à 4H3BO3 + Na2SO4 + 5H2O
Na2B4O7.10H2O + HCl à 4H3BO3 + 2NaCl + 5H2

Extraction of weak borax brine

Boric acid could be produced by extracting weak borax brine with a kerosene solution of an aromatic diol. The product of diol-borate chelate formed will be separated into a kerosene phase and treatment with sulfuric acid will produce boric acid in aqueous phase. Recrystallization is performed to purifiy the boric acid produced.

The Uses of Boric Acid

Boric Acid is used in fiberglass insulation, pharmaceutical and cosmetics, nutritional supplements, flame retardants, wood preservatives and past control and other applications. Besides, there is still much more about the use of this boric acid.

Wood Preservatives & Pest Control

Boric acid is a source of boron compounds and boron could inhibit the growth of fungus and hace been demonstrated to be a reliable wood preservative.

Nutritional Supplements

Boric acid contains an amount of boron that could be added to nutritional supplements. Boron has a therapeutic value in promoting bone and joint health and also preventing the arthritis symptoms.

Flame Retardant

Boric acid could inhibit the release of combustible gases from burning cellulosic materials such as wood and paper-based products. Boric acid also forms chemically bonded water to reduce combustion. Plastics, textiles, and specialty coatings also contain boric acid to avoid the damage after being exposed to flame.

Fiberglass Insulation

Boric acid helps the fiberization process of fiberglass to produce heat resistant, borosilicate, and other specialty glasses.

Pharmaceutical & Cosmetics Industry

Boric acid is a mild antiseptic that prevents the grows of microorganisms on the skin. It is also used in contact lens solutions, eye disinfectants, vaginal remedies, baby powder, anti-aging products, etc.

Other Applications

Boric acid is used in nuclear power plants to slow down the rate at which fission is occurring. By adding more boric acid to the reactor coolant which circulates through the reactor, the probability that a neutron can survive to cause fission is reduced. Therefore, boric acid concentration changes effectively regulate the rate of fissions taking place in the reactor. This is only done in Pressurized Water Reactors (PWR's).

PRODUCT IDENTIFICATION

IUPAC NameBoric Acid
CAS No10043-35-3
FormulaH3BO3
Molecular Weight61.83 g/mol
H.S. Code2810.00.20
SynonymsBoric acid; Boracic acid; Hydrigen borate; Orthoboric acid

PRODUCT SPECIFICATIONS

AppearanceWhite solid
OdorOdorless
pH5.2 (1% sol. at 20°C)
Vapor PressureNot available
Vapor DensityNot available
Evaporation RateNegligible
ViscosityNot applicable
Boiling PointNot available
Freezing/Melting Point339°C
Decomposition TemperatureNot available
Solubility4.9g / 100g water at 20°C
Specific Gravity/Density1.44 (water=1)