Product Description
HEDP (Hydroxyethylidene Diphosphonic Acid) is an organophosphonic acid-based scale inhibitor and corrosion inhibitor. It can form stable complexes with a variety of metal ions, including iron, copper, and zinc, while also helping dissolve metal oxides deposited on metal surfaces.
HEDP maintains excellent corrosion and scale inhibition performance at temperatures up to 250°C. It remains stable under high-pH conditions and is resistant to hydrolysis. Under normal light and heat exposure, it is not easily decomposed.
Compared with other organophosphonic acids and their salts, HEDP offers superior acid and alkali resistance as well as resistance to chlorine oxidation. It can react with metal ions in water, particularly calcium ions, to form stable chelate complexes, providing excellent scale inhibition and a significant threshold effect.
When combined with other water treatment chemicals, HEDP can provide excellent synergistic performance, making it suitable for a wide range of industrial water treatment applications.
Product Parameters
| Item | GB/T 26324-2010 | GB/T 26324-2010 | HG/T 3537-2010 |
| Appearance | Colorless to pale yellow transparent liquid | Colorless to pale yellow transparent liquid | White crystals |
| Active Component (as HEDP), % | ≥50.0 | ≥60.0 | ≥90.0 |
| Active Component (as HEDP·H₂O), % | — | — | ≥97.0 |
| Phosphite (as PO₃³⁻), % | ≤2.0 | ≤2.0 | ≤0.8 |
| Phosphate (as PO₄³⁻), % | ≤0.8 | ≤0.8 | ≤0.5 |
| Chloride (as Cl⁻), μg/g | ≤200 | ≤100 | ≤100 |
| Iron (as Fe²⁺), mg/L | ≤20.0 | ≤10.0 | ≤10.0 |
| Density at 20°C, g/cm³ | ≥1.36 | ≥1.40 | — |
| Calcium Chelation Value, mg/g | ≥450 | ≥500 | — |
| pH (1% aqueous solution) | 1.5–2.0 | 1.5–2.0 | 1.5–2.0 |
Application Scenarios
HEDP is widely used as a corrosion and scale inhibitor in:
Industrial circulating cooling water systems
Power generation plants
Chemical processing facilities
Metallurgical industries
Fertilizer production
Medium- and low-pressure boilers
Oilfield water injection systems
Oil transportation pipelines
In the light textile industry, HEDP can be used as a cleaning agent for metal and non-metal surfaces, as well as a peroxide stabilizer and fixing agent in textile bleaching and dyeing processes.
In cyanide-free electroplating, HEDP can function as a complexing agent.
In the pharmaceutical industry, HEDP can be used as a carrier agent for radioactive elements.
HEDP Solid
Solid HEDP is a high-purity product suitable for use in regions with extremely cold winters. It is particularly suitable for applications such as electronic industry cleaning formulations and additives for household and daily chemical products.
