What Is Borax?
Borax is a powdery white substance, also known as sodium borate, sodium tetraborate, or disodium tetraborate. It’s widely used as a household cleaner and a booster for laundry detergent. It’s a combination of boron, sodium, and oxygen.
Borax is often found in dry lake beds, where the water evaporated and left behind deposits of minerals.
Boric acid is made from the same chemical compound as borax and even looks like it. But while borax is commonly used in cleaning, boric acid is mainly used as a pesticide. Boric acid kills insects by targeting their stomachs and nervous systems.
Applications and benefits
- Soap and detergents
Borax decahydrate is incorporated in many cleaning products as a pH buffering agent, to aid in the emulsification of oils, and as a gentle abrasive. Borax decahydrate is added to powdered hand soaps to remove medium to heavy soils encountered in industrial operations. It is gentle to the skin, yet highly effective in removing dirt. Borax decahydrate is added to formulations to clean hard surfaces such as metals, glass, and ceramics. It is also used as an additive in hand cleaners, polishes and waxes, and industrial/institutional cleaning compounds. In laundry detergents, it facilitates the removal of oily soils from fabrics, and imparts alkalinity, pH buffering, and softening of the wash water. It is also used to stabilize enzymes.
- Personal care products
Borax decahydrate is used in cosmetics, toiletries, and pharmaceuticals. In contact lens solutions, it is used in conjunction with boric acid as a gentle cleaner and buffering agent. Borax decahydrate is also used as a crosslinking agent to emulsify waxes and other paraffins used as a base for lotions, creams, and ointments.
- Metallurgical fluxes
The ability of borax decahydrate to dissolve metal oxides is exploited in the recovery of metals such as brass, copper, lead, and zinc from scrap or smelting slag.
In ferrous metallurgy, borax decahydrate is used as a cover flux to prevent oxidation at the surface of the molten ingot. In welding, brazing, and soldering, borax decahydrate covers the metal surfaces, excluding air and preventing oxidation. It also acts as a solvent and cleaning agent.
- Corrosion inhibition
Borax decahydrate is incorporated in many aqueous systems requiring corrosion inhibition. It protects ferrous metals against oxidation and finds use in the manufacture of automotive and engine coolant formulations, and various water treatment chemicals.
The high solubility of borax decahydrate in ethylene glycol makes it especially useful in car antifreeze formulations. Borax decahydrate neutralizes the acidic residue resulting from the decomposition of ethylene glycol and minimizes the rate of oxidation at the surface of the metal. Aqueous solutions of borax decahydrate have replaced chromates in railroad and other diesel engine coolants.
Borax decahydrate is part of the starch adhesive formulation for corrugated paper and paperboard, and is a peptizing agent in the manufacture of casein-based and dextrin-based adhesives. It greatly improves the tack and green strength of the adhesive by crosslinking conjugated hydroxyl groups.
- Wire drawing
Borax decahydrate neutralizes the residual acid from the pickling stage, and the deposit of the salt remaining on the wire is valuable as a carrier of dry powdered lubricant.
Boraxdecahydrate compounds are used as stabilizers and bonding agents in specialty abrasives. Borax decahydrate gives an intermediate-temperature glassy bond prior to the establishment of the ceramic bond, at which point the borate compound is frequently volatilized from the system.
- Some other applications
Borax decahydrate is used as a flame retardant for cellulosic materials, a buffer and catalyst for organic dyes, a carrier for herbicides, a coolant for diesel engines, and a degreasing buffer in enamelling processes.