HEDP
1-Hydroxy Ethylidene-1,1-Diphosphonic Acid
CAS NO2809-21-4
Mol. WT.206.02
Mol. FormulaC2H8O7P2
Structure
- Properties
- Specification
- Usage
- Safety
- Package&Storage
HEDP is an organophosphoric acid corrosion inhibitor. It can chelate with Fe, Cu, and Zn ions to form stable chelating compounds.It can dissolve the oxidized materials on these metals’ surfaces. HEDP shows excellent scale and corrosion inhibition effects under temperature 250℃. HEDP has good chemical stability under high pH value, hard to be hydrolyzed, and hard to be decomposed under ordinary light and heat conditions. Its acid/alkali and chlorine oxidation tolerance are better than that of other organophosphoric acids (salt). HEDP can react with metal ions in water system to form hexa-element chelating complex, with calcium ion in particular. Therefore, HEDP has good antiscale and visible threshold effects. When built together with other water treatment chemicals, it shows good synergistic effects.
| Items |
GB/T26324-2010 |
HG/T3537-2010 |
| Appearance |
Colorless to pale yellow transparent liquid |
White powder solids |
| Active content (as HEDP)% |
50.0 min |
60.0 min |
90.0 min |
| Phosphorous acid (as PO33-)% |
2.0 max |
2.0 max |
0.80 max |
| Phosphoric acid (asPO43- )% |
0.8 max |
0.8 max |
0.50 max |
| Chloride (as Cl-) ppm |
0.1 max |
0.1 max |
0.1 max |
| pH (1% solution) |
1.5-2.0 |
1.5-2.0 |
1.5-2.0 |
| Density (20℃)g/cm3 |
1.34 min |
1.40 min |
—— |
| Active content (as HEDP·H2O), % |
—— |
—— |
98.0 min |
| Calcium chelating value，mg/g |
450 min |
500 min |
800 min |
| Fe (as Fe3+), mg/L |
10 max |
10 max |
5 max |
HEDP is used as scale and corrosion inhibition in circulating cool water system, oil field and low-pressure boilers in fields such as electric power, chemical industry, metallurgy, fertilizer, etc. In light woven industry, HEDP is used as detergent for metal and nonmetal. In dyeing industry, HEDP is used as peroxide stabilizer and dye-fixing agent; In non-cyanide electroplating, HEDP is used as chelating agent. The dosage of 1-10mg/L is preferred as scale inhibitor, 10-50mg/L as corrosion inhibitor, and 1000-2000mg/L as detergent. Usually, HEDP is used together with polycarboxylic acid.
Acidity. Avoid contact with eye and skin. In case of contact, flush with water immediately.
HEDP liquid: 30Kg/250Kg net in plastic drum.
HEDP solid: 25kg net in plastic woven bag.
Storage for twelve months in shady, cool and dry room with good ventilation.
