What is Sodium Tetraborate Decahydrate CAS 1303-96-4?

It is the refined sodium borate commonly called borax decahydrate, with the typical formula Na2B4O7·10H2O. This white crystalline grade contains about 36.5-38% B2O3 and differs from pentahydrate because it carries ten water molecules per formula unit.

Why is borax decahydrate used as a flux in soldering, brazing, and metal recovery?

At high temperature it forms a glassy melt that dissolves metal oxides and shields the metal surface from further oxidation. This improves wetting and flow of solder or braze alloy and helps recover precious metals from slags and concentrates.

What pH and water solubility should I expect?

A dilute aqueous solution of sodium tetraborate decahydrate is mildly alkaline, typically around pH 9.2-9.5 in the specification range shown above. Water solubility is about 50-60 g/L at 20 degrees C, so warm water or mixing time may be needed for higher concentrations.

Is this borax decahydrate suitable for food or cosmetic applications?

No. This product is labeled Industrial Grade, so it is not offered as a food additive or cosmetic ingredient. Applications requiring food, pharmaceutical, or personal-care compliance should use the appropriate regulated grade and confirm the required purity and documentation.

How should Sodium Tetraborate Decahydrate be stored to prevent caking?

Keep it in a cool, dry, ventilated area and keep the package tightly closed. The decahydrate can slowly lose water of crystallization in very dry or warm conditions, so protecting it from heat and moisture swings helps preserve its free-flowing crystalline form.

Sodium Tetraborate Decahydrate CAS 1303-96-4

Sodium Tetraborate Decahydrate (CAS 1303-96-4), commonly known as borax decahydrate, is a highly versatile granular crystalline compound widely utilized across heavy industrial and agricultural sectors. As an excellent alkaline buffer and mild flux, this stable borate mineral is essential for reducing the melting point in glass manufacturing, ceramic glazes, and metallurgical casting. Additionally, it serves as a critical boron micronutrient source in agricultural fertilizer blends. Unlike lower-grade alternatives that suffer from rapid efflorescence (loss of hydration), our sodium borate decahydrate is carefully processed and packed in moisture-controlled barriers to ensure absolute compound stability and precise boron content. We are fully equipped to manage reliable bulk supply for global manufacturers. By partnering with us, clients unlock competitive factory pricing, flexible customized specifications for various mesh sizes, and full shipment transparency supported by comprehensive MSDS, TDS, COA documentation.

CAS: 1303-96-4
Synonyms: Borax decahydrate, Sodium borate decahydrate, Disodium tetraborate decahydrate, Borax 10H2O, Sodium biborate.
Einecs: 215-540-4
Grade: Industrial Grade
Package: 25kg/bag, 50kg/bag, or 1000kg jumbo bag.

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Product Description

1 Technical Data (Physicochemical Properties)

2 Applications

3 Storage & Safety

4 Quality Assurance

Technical Data (Physicochemical Properties)

Property	Industrial Standard Specification
Appearance	White crystalline powder or granules
Assay	≥ 99.5%
Boron Trioxide	36.5% – 38.0%
Sodium Oxide	16.0% – 16.5%
pH Value (0.1% solution)	9.2 – 9.5
Insoluble Matter	≤ 0.04%
Sulfate	≤ 0.1%
Chloride	≤ 0.05%
Iron	≤ 0.002%

Applications

Glass & Ceramics: Essential in the production of borosilicate glass, fiberglass, and ceramic glazes to improve mechanical strength and chemical resistance.
Metallurgy: Used as a flux in gold recovery, brazing, and soldering to dissolve surface oxides and lower melting temperatures.
Industrial Detergents: Functions as a pH buffer, water softener, and enzymatic stabilizer in heavy-duty cleaning formulations.
Agriculture: Applied as a micronutrient fertilizer in boron-deficient soils to support cell wall synthesis in high-yield crops.

For other detergent builders and alkalinity-control materials, see Sodium Metasilicate.

Storage & Safety

Sodium Tetraborate Decahydrate should be stored in a cool, dry, well-ventilated area. It is slightly efflorescent (loses water of hydration) in very dry air, so airtight packaging is necessary to prevent clumping and maintain the 10H2O stoichiometry. PPE Recommendations: Operators should use dust-proof masks (N95 or equivalent), safety glasses with side shields, and nitrile gloves to prevent respiratory irritation and skin dryness during bulk handling.+1

Quality Assurance

Our facility utilizes automated crystallization and drying technologies to ensure precise control over the hydration state of the decahydrate crystal. Purity is verified through acid-base titration and ICP-OES for trace metal analysis, ensuring compliance with international industrial standards. We implement a rigorous batch-tracking system that aligns with ISO 9001 quality management frameworks, guaranteeing that the chemical performance remains consistent from the reactor to the end-user’s formulation.

FAQ - Technical & Supply Chain

Q:
What is Sodium Tetraborate Decahydrate CAS 1303-96-4?

A: It is the refined sodium borate commonly called borax decahydrate, with the typical formula Na2B4O7·10H2O. This white crystalline grade contains about 36.5-38% B2O3 and differs from pentahydrate because it carries ten water molecules per formula unit.
Q:
Why is borax decahydrate used as a flux in soldering, brazing, and metal recovery?

A: At high temperature it forms a glassy melt that dissolves metal oxides and shields the metal surface from further oxidation. This improves wetting and flow of solder or braze alloy and helps recover precious metals from slags and concentrates.
Q:
What pH and water solubility should I expect?

A: A dilute aqueous solution of sodium tetraborate decahydrate is mildly alkaline, typically around pH 9.2-9.5 in the specification range shown above. Water solubility is about 50-60 g/L at 20 degrees C, so warm water or mixing time may be needed for higher concentrations.
Q:
Is this borax decahydrate suitable for food or cosmetic applications?

A: No. This product is labeled Industrial Grade, so it is not offered as a food additive or cosmetic ingredient. Applications requiring food, pharmaceutical, or personal-care compliance should use the appropriate regulated grade and confirm the required purity and documentation.
Q:
How should Sodium Tetraborate Decahydrate be stored to prevent caking?

A: Keep it in a cool, dry, ventilated area and keep the package tightly closed. The decahydrate can slowly lose water of crystallization in very dry or warm conditions, so protecting it from heat and moisture swings helps preserve its free-flowing crystalline form.

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