99.9% high-purity large-crystal potassium nitrate: consistent quality for glass strengthening, molten-salt use and premium fertilizer programmes
Our 99.9% high-purity large-crystal potassium nitrate is produced by controlled crystallization, giving uniform, free-flowing crystals with very low impurity levels. It is a core raw material for the chemical strengthening of glass cover panels and optical glass. It also serves molten-salt and specialty industrial uses, and premium water-soluble fertilizer programmes where purity and consistency matter.
Core advantages of the product
Ultra-high purity
- KNO₃ content ≥ 99.9%, with chloride, sulfate, sodium, iron and heavy metals all tightly limited
- Low chloride (≤ 0.005%) and low heavy metals (≤ 0.001% as Pb) help prevent contamination and corrosion of the glass surface during strengthening
- Low sodium (≤ 0.02%): sodium released from the glass builds up in a strengthening bath, so starting with a low-sodium salt helps keep the bath stable for longer
Large, uniform crystals
- Controlled crystallization produces large crystals of uniform size
- Less dust and less agglomeration during packing, transport and feeding
- Lower moisture pickup and better storage stability than fine-crystal products
Controlled crystallization process
- Produced with a vacuum crystallization process that allows precise control of crystal growth
- Uniform, free-flowing crystals that resist caking and stay chemically consistent in use
Improve efficiency and yield
High-purity raw material means less impurity interference, which helps lower the defect rate in glass strengthening and gives your production line better output and economics.
Parameters
| Test Item | Technical Indicator | Test Result |
|---|---|---|
| Potassium nitrate (KNO₃) | ≥ 99.9% | 99.91% |
| pH Value | 5.0–8.0 | 5.80 |
| Water Insolubles | ≤ 0.05% | 0.0016% |
| Chloride ion (Cl⁻) | ≤ 0.005% | < 0.0025% |
| Iodate (IO₃⁻) | ≤ 0.002% | < 0.002% |
| Sulfate (SO₄²⁻) | ≤ 0.01% | < 0.003% |
| Nitrite (NO₂⁻) | ≤ 0.001% | < 0.001% |
| Ammonium (NH₄⁺) | ≤ 0.005% | < 0.005% |
| Phosphate (PO₄³⁻) | ≤ 0.001% | < 0.001% |
| Sodium (Na) | ≤ 0.02% | 0.00059% |
| Calcium (Ca) | ≤ 0.001% | 0.00015% |
| Magnesium (Mg) | ≤ 0.001% | 0.000048% |
| Iron (Fe) | ≤ 0.0005% | < 0.0004% |
| Heavy metals (as Pb) | ≤ 0.001% | < 0.001% |
| Crystal size | [fill in, e.g. – mm] | [fill in] |
Application field
- Chemical strengthening of glass: molten-salt ion exchange for mobile phone and tablet cover glass, automotive touch screens and optical glass.
- Glass clarifying agent: used in high-end glass such as automotive lamp glass and optical glass.
- Metal heat treatment: a component of quenching salt baths.
- Premium water-soluble fertilizers: drip irrigation, greenhouse and hydroponic production where chloride must be minimal and dissolution consistent.
- Specialty chemical processing and industrial formulations that require strict impurity control.
Packaging, Storage and Safety Instructions
- Packaging: 25 kg or 50 kg bags, or 1-ton bags.
- Storage: keep in a cool, dry, well-ventilated warehouse, away from fire and heat sources and from reducing substances.
- Transport: UN 1486, Class 5.1 oxidizer; use sealed packaging and ship separately from combustible and reducing materials.
- Safe operation: in a molten-salt system, keep the medium clean and never let it contact water, organic matter or reducing substances, as this can cause violent reactions.
- Control the heating rate strictly to avoid sudden heating or cooling of the system.
Why choose us?
- Factory-backed supply: three production bases and export experience support stable, repeat supply.
- Technology and quality: continuous investment in research and development keeps product quality stable, and our production partner takes part in drafting national standards.
- Quality assurance: COA, SDS and TDS are provided with each shipment, and the product has passed HF and RoHS testing by the third-party laboratory SGS.
FAQ
Q: What does “large crystal” mean, and why does crystal size matter?
A: Large-crystal grades are grown to a bigger and more uniform crystal size than fine crystals or powder. This means less dust, better flow, lower moisture pickup and less caking during storage and transport, and easier feeding into dissolving or melting equipment. The exact crystal size range is available on request.
Q: Why does glass chemical strengthening need 99.9% potassium nitrate?
A: In chemical strengthening, glass is immersed in molten potassium nitrate, where potassium ions replace smaller sodium ions in the glass surface and create compressive stress. Chloride, sulfate and heavy-metal impurities can attack the glass surface or the bath, and sodium from the glass gradually builds up in the bath. Starting with a high-purity, low-sodium salt helps protect surface quality and keeps the bath stable for longer.
Q: Is this grade suitable for fertigation?
A: Yes. The large crystals dissolve consistently and chloride is very low, so it works well in precision irrigation. For routine fertigation, our agricultural grade is usually the more economical choice, while this 99.9% grade is mainly for glass and specialty uses.
Q: How should it be stored and shipped?
A: Keep it dry and sealed, away from fire, heat, fuels and reducing substances. It ships as UN 1486, Class 5.1, in sealed packaging, separately from combustible materials.
Q: Can I get a sample and technical data?
A: Yes. Send us your application and required specification, including crystal size and packaging, and we will provide samples, COA, TDS and SDS on request.
Consult now to get samples and technical data
If you need a high-purity, consistent potassium nitrate for glass strengthening or other demanding uses, our 99.9% large-crystal grade is a strong choice. Contact us to request samples and detailed specifications, and our expert team will support you.