Types of Borax and Differences

2024-06-25

The main types of borax include borax decahydrate, borax pentahydrate and borax anhydrous. The main difference between these boraxes is the amount of crystalline water they contain and the amount of boron oxide. Specifically:

Borax decahydrate (Na₂B₄O₇-10H₂O) contains 10 crystalline waters and its boron oxide content is relatively low.

Borax pentahydrate (Na₂B₄O7-5H₂O) contains 5 crystalline waters, and its boron oxide content is higher compared with borax decahydrate.

Anhydrous borax (Na₂B₄O₇), on the other hand, does not contain water of crystallization, and its boron oxide content reaches its highest in the anhydrous state.

In addition, there are other compositions of borax besides these three basic boraxes, and these differences mainly affect the physical and chemical properties of borax, which in turn affect its uses and safety. For example, borax decahydrate and borax pentahydrate are used differently in industrial production. In the past, most of the glass industry used borax decahydrate, but nowadays most of the countries prefer borax pentahydrate because of the higher content of boron oxide and the reduced amount of water of crystallization in borax pentahydrate, which provides superior storage and bulk transportation properties.

Overall, the types of borax and the differences are mainly in the amount of water of crystallization and the content of boron oxide, and these differences affect the physicochemical properties, uses, and safety of borax.