The difference between physical properties of boric acid and borax

Many people cannot distinguish between borax and boric acid, especially those who are not familiar with them are easily confused. Borax and boric acid are both raw materials in the boron industry, but borax is finer and is a colorless, translucent crystal, similar to table salt, while boric acid is powdery and has a greasy feel. Both have certain application value. So what are the differences between borax and boric acid?

Differences between Boric Acid and Borax in Chemical Properties

Boric acid has higher solubility than borax. Boric acid is easily soluble in water, alcohol, glycerin, ethers and essential oils. Its aqueous solution is mildly acidic and its chemical form is H3BO3. Its solubility in water increases with increasing temperature and it can evaporate with water vapor. Its solubility in inorganic acids is lower than that in water. When heated to 70-100°C, it gradually dehydrates to form metaboric acid, forms pyroboric acid at 150-160°C, and forms boric anhydride, also called boron oxide B2O3, at 300°C. Borax is easily soluble in water and glycerin, and slightly soluble in alcohol. The aqueous solution is weakly alkaline, with the chemical formula Na2B4O7=10H2O. Borax can weather slowly in the air and become a colorless glassy substance when melted.

The difference between boric acid and borax in industry use

1) In glass, boric acid is widely used in the glass industry (optical glass, acid-resistant glass, heat-resistant glass, glass fiber for insulating materials), which can improve the heat resistance and transparency of glass products, increase mechanical strength and shorten melting time. Borax can enhance the transmittance of ultraviolet rays and improve the transparency and heat resistance of glass.

2) In enamel products, boric acid is used to enhance the gloss and fastness of enamel products. It is also one of the components of glaze and pigment. Borax can make the glaze less likely to fall off and make it shiny.

3) In fine chemicals, boric acid is used as chemical reagents, detergents, additives, fungicides, wood preservatives and raw materials for compounds. It can also be used as a bleaching agent, mordant, finishing agent, dye stabilizer, and in the manufacture of leather processing, photography, artificial gemstones, heat-resistant and fire-resistant fabrics, and cosmetic fragrances. Borax is used as a filler in laundry detergent and soap, and is also a raw material for artificial gemstones, welding flux, etc., and a rust remover for metal surfaces.

4) In medicine, boric acid is often used as a hemostatic agent. For example, applying 3% boric acid to the face with a towel or facial mask has a good effect in reducing swelling and redness. It is used in the production of boric acid ointments, disinfectants, astringents, preservatives, etc. Borax, after being extracted and refined, can be used as a heat-clearing and detoxifying medicine. It is cool in nature, sweet and salty in taste, and can treat various symptoms such as sore throat and mouth ulcers.

5) In agriculture, boric acid can be used as an insecticide and herbicide to produce boron-containing trace fertilizers. Boric acid and borax are mixed into an aqueous solution and sprayed as foliar fertilizer.

During production, borax and triacid can react to produce boric acid, which is the so-called two-step boric acid production process. Borax can be divided into domestic and imported, and also divided into decahydrate and pentahydrate. The quality of the boric acid produced is also different. Boric acid expert De'er Boron Industry warmly reminds customers to keep their eyes open for quality and not to covet temporary cheapness, causing unpredictable losses.