Potassium Metaphosphate
Potassium Metaphosphate is the long-chain crystalline polymer of potassium phosphate with the formula (KPO3)n, where the chain length ranges from several hundred to several thousand phosphate units.
The salt is a white free-flowing powder that is largely insoluble in cold water and slowly soluble in hot water. It is the potassium analogue of crystalline sodium polyphosphate (Maddrell's salt), with the same regular crystalline structure and slow dissolution behaviour.
We source bulk Potassium Metaphosphate from top China manufacturers for our partners, working with several of them. The manufacturers are in Jiangsu and Sichuan. For this ingredient the minimum order is 500 kg and a 20-foot container takes 20 MT, and a smaller requirement can ship in a combined container with other ingredients.
Please send the grade you need, the volume and your destination port, and we will come back with a solution and a price.
or call +86-21-6858 0751
- Minimum order
- 500 kg
- Qty in 20' FCL
- 20 MT
- Packaging
- 25 kg kraft paper bag with PE inner liner
- Function
- Meat-processing aid
- ISO 9001
- HACCP
- Halal
- Kosher
Specifications
| Item | Specification |
|---|---|
| Appearance | White free-flowing crystalline powder |
| Assay ((KPO₃)n, dried basis) | ≥ 95.0% |
| Total P₂O₅ | 59.0–61.0% |
| K₂O Content | 38.0–41.0% |
| Solubility | Practically insoluble in cold water; slowly soluble in hot water and dilute acid |
| pH (1% aqueous suspension, 25°C) | 5.5–7.5 |
| Loss on Ignition (550°C) | ≤ 2.0% |
| Acid-Insoluble Matter | ≤ 0.2% |
| Fluoride (as F) | ≤ 10 mg/kg |
| Chloride (as Cl) | ≤ 0.05% |
| Sulfate (as SO₄) | ≤ 0.1% |
| Heavy Metals (as Pb) | ≤ 10 mg/kg |
| Lead (as Pb) | ≤ 2 mg/kg |
| Arsenic (as As) | ≤ 3 mg/kg |
| Particle Size | 95% through 80 mesh |
Common Markets Grades
Potassium metaphosphate is produced principally in food-grade and pharmaceutical-grade qualities.
Food-grade material conforms to FCC and E 452(ii) purity specifications, with minimum 95 percent (KPO3)n assay on a dry basis, calculated from total P2O5 content.
Pharmaceutical-grade material conforms to USP and Ph. Eur. monographs and is used as a potassium source in oral electrolyte formulations and as a slow-release phosphate in nutritional and dental products.
Particle size is the secondary specification axis, ranging from fine micronised powder for toothpaste and supplement applications to coarser granular grades for industrial use.
The salt is essentially insoluble in cold water, with solubility limited to a few hundred parts per million. Solubility rises in hot water and in dilute acid.
Applications
- Bakery and dough conditioning as a slow-release phosphate
- Nutritional supplement formulations as a potassium and phosphate source
- Pharmaceutical electrolyte and rehydration powders
- Toothpaste as a polishing abrasive and slow-release phosphate
- Cheese-product formulations as a slow-acting emulsifying salt
- Meat phosphate blends paired with short-chain phosphates for shelf-life protection
- Pet food specialty formulations for slow-release mineral delivery
- Industrial liquid detergent and cleaning compound builders
- Plant fertiliser slow-release potassium-phosphate component
- Water-treatment scale inhibition in cooling-tower systems
China Manufacturers of Potassium Metaphosphate
Top Potassium Metaphosphate manufacturers in China.
Jiangsu Hens Food Technology Co., Ltd.11 ingredients in the directory
Sichuan Kindia May Science And Tech.Co., Ltd.14 ingredients in the directory- Xuzhou Hens Phosphate Co., Ltd.11 ingredients in the directory
Company names and logos are the property of the manufacturers themselves. They are listed here because our own directory records them as producing this ingredient. A listing is not an endorsement by them, and we do not represent them or speak on their behalf.
How We Help Source Potassium Metaphosphate
Direct Factory Sourcing
We run the whole process: selecting the manufacturer from the top Chinese food ingredient producers, negotiating the price, verifying quality, and coordinating the logistics. You deal with us instead of with several factories at once.
Original Packaging and Documents from the Manufacturer
The manufacturer sends your Potassium Metaphosphate out of its own factory in the original packing, through to your destination port. The COA, COO, MSDS, TDS and any certifications reach you from the manufacturer as well.
Free Samples and Lead Time
We send 100 to 500 g free for your own laboratory to test and you cover only the courier, usually within 2 to 3 working days. ETD is usually within 7 to 15 days once the order is confirmed, and we check that date against the factory's own manufacturing schedule before we give it to you.
Combined Shipment
We can load Potassium Metaphosphate together with other ingredients such as Sodium Tripolyphosphate, Sodium Hexametaphosphate and TetraSodium Pyrophosphate into one 20' FCL. If your quantity is small, we can also ship LCL.
Regulatory Status
Potassium metaphosphate is approved as a food additive in major regulated markets.
The European Union lists it as E 452(ii) within the polyphosphate sub-family of phosphate additives. The U.S. FDA recognises it under 21 CFR 182.1810 (GRAS) and within the general phosphate sequestrant entries.
JECFA evaluates the substance within its group assessment of phosphate additives.
FCC, USP, and Ph. Eur. monographs cover identity, assay, and impurity limits. Halal and Kosher certifications are routinely available.
The substance has a smaller commercial volume than its sodium analogue because applications that demand high water solubility are better served by other potassium phosphates, and applications that benefit from crystalline insolubility are a relatively small market.
Manufacturing Process
Potassium metaphosphate is produced by extended thermal condensation of monopotassium orthophosphate, followed by controlled cooling that favours the regular crystalline polymer structure.
Monopotassium orthophosphate (KH2PO4) is prepared by neutralising food-grade phosphoric acid with potassium hydroxide or potassium carbonate at a 1:1 mole ratio. The solution is concentrated and dried.
The dried salt is calcined in continuous furnaces at 600 to 800 degrees Celsius for extended dwell times. The condensation eliminates one water molecule per orthophosphate unit and links the phosphates into long linear chains.
The cooling step is critical. Slow cooling through the crystallisation window allows the chains to align into the regular crystalline lattice, producing the insoluble crystalline form. Rapid quenching would produce a glassy potassium polyphosphate instead.
The cooled product is milled, sieved, and tested by X-ray diffraction and 31P NMR to confirm the crystalline phase and chain length distribution.
