Borax

Jai Ganesh · 2025-04-03 18:14:13

Borax

Gist

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.

Summary

Borax is sodium tetraborate decahydrate (Na2B4O7·10H2O). A soft and light, colourless crystalline substance, borax is used in many ways—as a component of glass and pottery glazes in the ceramics industry, as a solvent for metal-oxide slags in metallurgy, as a flux in welding and soldering, and as a fertilizer additive, a soap supplement, a disinfectant, a mouthwash, and a water softener.

Borax has been known since early times, when it was obtained from saline lakes in Kashmir and Tibet and taken to Europe to be refined. It has been produced commercially from colemanite, kernite, and tincalconite, as well as from the mineral borax, by dissolving the ore in water, filtering out the clay, and evaporating the solution. Colemanite was the chief source until the 1930s, when it was supplanted by kernite, which was subsequently replaced by the mineral borax. About 50 percent of the world’s supply of commercial boron compounds comes from southern California: the borax crusts and brine from Searles Lake, the large kernite and borax deposits near Kramer, and the colemanite deposits from Death Valley, formed by the evaporation of hot springs or saline lakes and playas.

Details

Borax (also referred to as sodium borate, tincal and tincar is a salt (ionic compound), a hydrated or anhydrous borate of sodium, with the chemical formula Na2H20B4O17.

It is a colorless crystalline solid that dissolves in water to make a basic solution.

It is commonly available in powder or granular form and has many industrial and household uses, including as a pesticide, as a metal soldering flux, as a component of glass, enamel, and pottery glazes, for tanning of skins and hides, for artificial aging of wood, as a preservative against wood fungus, and as a pharmaceutic alkalizer. In chemical laboratories, it is used as a buffering agent.

The terms tincal and tincar refer to native borax, historically mined from dry lake beds in various parts of Asia.

History

Borax was first discovered in dry lake beds in Tibet. Native tincal from Tibet, Persia, and other parts of Asia was traded via the Silk Road to the Arabian Peninsula in the 8th century AD.

Borax first came into common use in the late 19th century when Francis Marion Smith's Pacific Coast Borax Company began to market and popularize a large variety of applications under the 20 Mule Team Borax trademark, named for the method by which borax was originally hauled out of the California and Nevada deserts.

Natural sources

Borax occurs naturally in evaporite deposits produced by the repeated evaporation of seasonal lakes. The most commercially important deposits are found in: Boron, California; and Searles Lake, California. Also, borax has been found at many other locations in the Southwestern United States, the Atacama Desert in Chile, newly discovered deposits in Bolivia, and in Tibet and Romania. Borax can also be produced synthetically from other boron compounds.

Naturally occurring borax (known by the trade name Rasorite–46 in the United States and many other countries) is refined by a process of recrystallization.

Uses

Borax is used in pest control solutions because it is toxic to ants and rats. Because it is slow-acting, worker ants will carry the borax to their nests and poison the rest of the colony. Borax is more effective than zinc borate for termite control but a 1997 paper concluded that exposing at least 10% of the total colony population was needed for effective treatment. In Japan the practice of laying newspapers treated with o-boric acid and borax under buildings has been effective in controlling Coptotermes formosanus and Reticulitermes speratus populations. Decaying wood treated with 0.25 to 0.5 percent DOT was also found to be effective for baiting Heterotermes aureus populations. The paper concluded: "Borate baits would undoubtably be helpful in the long-term, but do not appear sufficient as a sole method of structural protection."

Borax is used in various household laundry and cleaning products, including the 20 Mule Team Borax laundry booster, Boraxo powdered hand soap, and some tooth bleaching formulas.

Borate ions (commonly supplied as boric acid) are used in biochemical and chemical laboratories to make buffers, e.g. for polyacrylamide gel electrophoresis of DNA and RNA, such as TBE buffer (borate buffered tris-hydroxymethylaminomethonium) or the newer SB buffer or BBS buffer (borate buffered saline) in coating procedures. Borate buffers (usually at pH 8) are also used as preferential equilibration solutions in dimethyl pimelimidate (DMP) based crosslinking reactions.

Borax as a source of borate has been used to take advantage of the co-complexing ability of borate with other agents in water to form complex ions with various substances. Borate and a suitable polymer bed are used to chromatograph non-glycated hemoglobin differentially from glycated hemoglobin (chiefly HbA1c), which is an indicator of long-term hyperglycemia in diabetes mellitus.

The sodium ions introduced do not make water "hard". This method is suitable for removing both temporary and permanent types of hardness.

A mixture of borax and ammonium chloride is used as a flux when welding iron and steel. It lowers the melting point of the unwanted iron oxide (scale), allowing it to run off. Borax is also mixed with water as a flux when soldering jewelry metals such as gold or silver, where it allows the molten solder to wet the metal and flow evenly into the joint. Borax is also a good flux for "pre-tinning" tungsten with zinc, making the tungsten soft-solderable. Borax is often used as a flux for forge welding.

In artisanal gold mining, borax is sometimes used as part of a process known as the borax method (as a flux) meant to eliminate the need for toxic mercury in the gold extraction process, although it cannot directly replace mercury. Borax was reportedly used by gold miners in parts of the Philippines in the 1900s. There is evidence that, in addition to reducing the environmental impact, this method achieves better gold recovery for suitable ores and is less expensive. This borax method is used in northern Luzon in the Philippines, but miners have been reluctant to adopt it elsewhere for reasons that are not well understood. The method has also been promoted in Bolivia and Tanzania.

A rubbery polymer sometimes called Slime, Flubber, 'gluep' or 'glurch' (or erroneously called Silly Putty, which is based on silicone polymers), can be made by cross-linking polyvinyl alcohol with borax. Making flubber from polyvinyl acetate-based glues, such as Elmer's Glue, and borax is a common elementary science demonstration.

Additional Information

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 in places like California’s Death Valley, 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.

Both borax and boric acid in loose powder form can be harmful if swallowed, particularly for children. They can also irritate your skin.

Borax, also known as sodium borate or sodium tetraborate, is a naturally occurring mineral that has been used for various purposes throughout history. It is composed of boron, sodium, oxygen, and water molecules. The chemical formula for borax is Na2B4O7·10H2O.

Math Is Fun Forum

#1 2025-04-03 18:14:13

Borax

Board footer