HEDP 60% (Etidronic Acid)
High-purity 1-Hydroxyethylidene-1,1-Diphosphonic Acid (HEDP 60%) with strong chelating affinity for iron, copper, and calcium ions. Provides dual threshold scale inhibition and cathodic corrosion passivation.
Technical Specification Target
Chelation & Corrosion Inhibition Chemistry
HEDP coordinates with polyvalent metal ions through two covalent C-P bonds, forming strong hexadentate chelate rings with calcium, magnesium, and dissolved iron.
Unlike inorganic polyphosphates that readily hydrolyze into orthophosphate, HEDP resists chemical and thermal hydrolysis, remaining stable across operating temperatures up to 200°C.
Standard Industrial Dosage
| Application | Recommended Dosing |
|---|---|
| Recirculating Cooling Water | 2.0 – 10.0 ppm |
| Low-Pressure Steam Boilers | 5.0 – 20.0 ppm |
| Peroxide Bleach Stabilization | 1.0 – 3.0 g/L |
| RO Antiscalant Formulation | 2.0 – 5.0 ppm |
Packaging, Handling & Storage
- Packaging Options: 65 kg carboys, 250 kg virgin HDPE drums, 1,250 kg IBC totes, and rubber-lined road tankers.
- Storage Conditions: Store in acid-proof plastic or lined tanks in a cool, well-ventilated dry warehouse. Avoid plain carbon steel.
- Shelf Life: 24 months from manufacturing date.
- Handling Safety: Corrosive acidic liquid. Wear chemical goggles, face shield, and rubber gloves.
Frequently Asked Questions: HEDP 60% (Etidronic Acid)
Expert technical answers on dosing, chemistry, handling, and application performance.
Q1. What is HEDP 60% (Etidronic Acid) and what are its key properties?
HEDP 60% (CAS 2809-21-4) is an organophosphonic acid scale and corrosion inhibitor exhibiting strong multi-valent metal ion chelation (Fe, Cu, Zn, Ca) and high chemical stability up to 200°C.
Q2. What is the recommended dosing concentration of HEDP 60% in cooling towers?
In open recirculating cooling water systems, typical continuous dosage is 2.0 to 10.0 ppm active. In low-pressure industrial boilers, dosing is 5.0 to 20.0 ppm.
Q3. How does HEDP function in hydrogen peroxide bleach stabilization?
In textile processing and pulp bleaching, HEDP (1.0 to 3.0 g/L) strongly chelates trace iron, copper, and manganese ions, preventing catalytic decomposition of hydrogen peroxide.
Related Phosphonates & Polymers
Polyacrylic Acid (PAA 50%)
Synergistic polymer partner for comprehensive scale control.