Tungsten chemicals · Na₂WO₄·2H₂O
Sodium Tungstate (Na₂WO₄·2H₂O)
Water-soluble tungsten chemistry at assay ≥ 99%, for pigments, corrosion inhibitors, flame retardants and catalyst preparation.
About Sodium tungstate
Sodium tungstate dihydrate is the water-soluble entry point to tungsten chemistry. Where metal powder and carbide are used for their physical properties, sodium tungstate is used for what tungsten does in solution — which makes it the natural precursor wherever tungsten has to be introduced to a wet process.
It appears industrially as an intermediate in tungsten refining, since digesting concentrate produces sodium tungstate liquor before APT is crystallised from it. Sold as a product, it is the precursor for tungstate pigments, the active component of tungstate corrosion inhibitors, and the tungsten source in a range of catalyst preparations.
We supply it at assay min. 99% on an anhydrous basis, as a white crystalline powder freely soluble in water, with a calculated WO₃ content of approximately 71.8% and molecular weight 329.86 g/mol.
Specifications
| Formula | Na₂WO₄·2H₂O |
|---|---|
| Molecular weight | 329.86 g/mol |
| Assay, min. | ≥ 99 % (anhydrous basis) |
| Appearance | White crystalline powder |
| Solubility | Freely soluble in water |
| WO₃ content (calculated) | ~71.8 % |
Specifications can be tailored to order. Confirm your target values with us before placing an order and we will state honestly whether they are achievable.
Specifying for your application
Most sodium tungstate applications are sensitive to specific trace contaminants rather than to bulk assay, since the material is going into solution regardless. Tell us which contaminants your process cannot tolerate and we will confirm against them before quoting.
Corrosion inhibition
Bulk assay and chloride content are usually the controlling specifications.
Catalyst preparation
Trace metals matter most, since they can poison the catalyst at concentrations well below the assay tolerance.
Pigments and flame retardants
Colour, consistency and bulk assay lead; trace metal limits are generally less demanding.
Applications
Corrosion inhibitors
Tungstate inhibitors passivate steel in closed cooling systems and are used where chromate and nitrite chemistries are restricted on toxicity or discharge grounds. This is a growing use as those restrictions tighten.
Inorganic tungstate pigments
Precursor for tungstate pigment systems and for phosphors, where tungsten's heavy atom contributes to the optical behaviour of the finished material.
Fireproofing and flame retardants
Tungstate compounds are used in flame-retardant treatments for textiles and coatings, typically as part of a halogen-free formulation.
Catalyst preparation
A water-soluble tungsten source for impregnating supports in catalyst manufacture, where solution chemistry is the whole point and trace metal purity is the controlling specification.
Quality control
- Assay determination on an anhydrous basis against the 99% minimum
- Appearance and solubility check
- Trace contaminant scan where the application requires it
- Full composition table on the certificate of analysis
- Third-party test certificates available on request
Manufactured under an ISO 9001:2015 certified quality management system.
Packaging and export
Packed in lined drums or bags with moisture barrier, palletised for container shipment. The dihydrate is hygroscopic in humid conditions, so the barrier packing protects the assay through long sea-freight legs.
Commercial invoice, packing list, certificate of analysis and certificate of origin are supplied as standard with every export shipment.
Sodium tungstate — frequently asked questions
What assay do you supply?
Minimum 99% on an anhydrous basis, with a calculated WO₃ content of approximately 71.8%. The full composition table is stated on the certificate of analysis.
Is it the dihydrate or the anhydrous salt?
We supply the dihydrate, Na₂WO₄·2H₂O, molecular weight 329.86 g/mol. Assay is quoted on an anhydrous basis, which is the normal convention.
How should it be stored?
Dry and sealed. The dihydrate is hygroscopic in humid conditions, and picked-up moisture shifts the effective assay of what you weigh out.
Can you meet specific trace metal limits?
Often, yes — but tell us the limits before ordering rather than after. Catalyst applications in particular are sensitive to trace metals at concentrations far below the bulk assay tolerance, and we would rather confirm against your list up front than have a lot rejected.
Do you provide composition data for REACH or SDS obligations?
Yes. A full composition table accompanies each shipment on the certificate of analysis, which supports safety data sheet obligations and incoming-material qualification for chemical imports.
Sodium tungstate export destinations
Country-specific specifications, logistics and compliance notes for this product: