Product Introduction
Also known as: Anhydrous Sodium Tetraborate, Sodium Tetraborate, Sodium Borate
English Name: Sodium Tetraborate
Chemical Formula: Na₂B₄O₇
Molecular Weight: 201.22
Main Content: ≥95%
Quality Standard: GB/T537-2009
CAS No.: 1330-43-4
HS Code: 2840110000
Product Features
Anhydrous borax appears as white crystals or colorless glassy crystals.The α-orthorhombic crystal has a melting point of 742.5℃ and a density of 2.28 g/cm³;the β-orthorhombic crystal has a melting point of 664℃ and a density of 2.75 g/cm³. It has strong hygroscopicity, is soluble in water and glycerol, and slowly soluble in methanol to form a solution with a concentration of 13–16%. Its aqueous solution is weakly alkaline, and it is insoluble in ethanol. Anhydrous borax is the anhydrous substance obtained by heating borax at 350~400℃. When exposed to air, it absorbs moisture and converts into decahydrate borax or pentahydrate borax.
Technical Indicators
Inspection items | Inspection specification |
Main content (Na2B4O7) | ≥95 |
Sodium oxide (Na2O)% | ≥29 |
Boron oxide(B2O3)% | ≥65 |
Boron % | ≥21 |
Content of sodium carbonate (Na2CO3) % | ≤0.4 |
Water insoluble content % | ≤0.1 |
Sulphate(as SO4)Content % | ≤0.4 |
Chloride(CL)content % | ≤0.03 |
moisture content % | ≤1 |
Iron(Fe)content % | ≤0.005 |
Average grain size | 40-60Mesh |
Application Scope
▶ It serves as a carrier for lubricants in metal wire drawing, and acts as a stabilizer and framework forming agent in refractory materials.
▶ Applied in high-quality glass, glaze, welding flux, and as a flux for non-ferrous metals and alloys.
▶ Used as a retarder for cement and concrete, a pH buffer in water systems, and an emulsifier for paraffin wax.
▶ Borax is a basic raw material for preparing boron-containing compounds; almost all boron compounds can be produced from borax.
▶ Its other properties are similar to those of ordinary borax.

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