Physical and chemical properties：
Potassium pyrophosphate (also known as: tetrapotassium pyrophosphate, anhydrous potassium pyrophosphate) is prepared by melting dipotassium hydrogen phosphate to lose water molecules. It is a colorless or white crystal, or white crystalline powder or granule. Potassium pyrophosphate has a relative density of 2.534 and a melting point of 1109°C. It has strong hygroscopicity in the air, is soluble in water but insoluble in ethanol, and its aqueous solution is alkaline. The solubility of potassium pyrophosphate in 100g of water at 25°C is 187g.
Potassium pyrophosphate possesses all the properties of other polymeric phosphates. It is similar to sodium pyrophosphate but has higher solubility, and can chelate with alkaline earth metal and heavy metal ions. It can form stable complexes with Ca²⁺ and Mg²⁺ in hard water, thereby softening hard water, enhancing detergency and removing dirt. In addition, potassium pyrophosphate can form a protective film on the surface of metals such as iron, lead, zinc and aluminum. The pyrophosphate ion (P₂O₇⁴⁻) has a strong dispersing ability for finely dispersed solids, which can promote the uniform mixing of fine and trace substances. High-purity and low-iron potassium pyrophosphate has stable pH buffering capacity, which can maintain the pH value of the solution for a long time.。
Applications：
Potassium pyrophosphate (TKPP) is a white crystalline powder, widely used in fields such as electroplating, industrial cleaning, food processing, and fertilizers. Its excellent complexing, chelating, and pH-regulating capabilities make it an indispensable functional raw material in various industries.
Electroplating-grade potassium pyrophosphate (with a purity of ≥99%) is renowned for its high purity and stable performance, and it is a key material in cyanide-free electroplating processes. By complexing metal ions (such as copper and zinc), it ensures uniform and dense coatings, improves surface finish, and protects the substrate. It is suitable for precision electroplating scenarios such as auto parts, electronic components, steel cord, copper foil, and sanitary ware.
Industrial-grade potassium pyrophosphate is widely used in industries like detergents, ceramics, bleaching and dyeing, and surface treatment due to its cost-effectiveness and versatility. Its ability to chelate calcium and magnesium ions can soften hard water and enhance decontamination effects; in the ceramic industry, it acts as a clay dispersant to improve the stability of glazes; in bleaching and dyeing, it is used to remove iron ions to ensure uniform dyeing; in surface treatment, it functions to remove oil stains and form a protective film.
As a safe food additive, food-grade potassium pyrophosphate is mainly used for color protection of aquatic canned products, improvement of baking dough, and moisture retention of meat products. Its characteristic of chelating metal ions can prevent the formation of struvite and extend the shelf life of food; at the same time, it improves the taste, such as increasing the expansion degree of ice cream and the tenderness of meat products.
| Specifications | Electroplating-grade | Industrial-grade | food-grade | |
|---|---|---|---|---|
| Packing: | 25kg/bag, in woven or kraft paper bags with inner bag,or as customer's requirements. | |||
| Appearance | white powder or granular | white powder or granular | white powder or granular | |
| Assay(K4P2O7) % | ≥99 | ≥98 | ≥96 | |
| P2O5 % | 43 approx | 43 approx | 43 approx | |
| K2O % | 56 approx | 56 approx | 56 approx | |
| Fe % | ≤0.002 | ≤0.005 | / | |
| As % | ≤0.0003 | ≤0.0003 | ≤0.0003 | |
Heavy metal(as Pb) % | ≤0.001 | ≤0.001 | ≤0.001 | |
| pH(1%sol.) | 10.0~11.0 | 10.0~11.0 | 10.0~11.0 | |
| Water insoluble % | ≤0.1 | ≤0.1 | ≤0.1 | |
| Loss on ignition % | ≤0.5 | ≤0.5 | ≤0.5 | |
Transportation conditions: It is strictly prohibited to mix and transport with oxidants, acids, edible chemicals, etc. During transportation, exposure to sunlight, rain, and high temperatures should be prevented. The vehicle should be cleaned after transportation. For road transportation, it shall follow the specified route. Air transportation: Potassium pyrophosphate can be handled under ordinary cargo conditions.
Storage conditions: It should be stored in a cool and dry place. Attention should be paid to protecting it from sunlight, moisture and package damage. It is recommended to stack it on shelves or single-layer pallets.
Shelf life: Under the above storage and transportation conditions, the shelf life is 12 months.
