HEDP 60
1-Hydroxy Ethylidene-1,1-Diphosphonic Acid 60%
CAS: 2809-21-4
C2H8O7P2
Description
HEDP is an organophosphoric acid chelating agent. It can chelate with Fe, Cu, and Zn ions to form stable chelating compounds.It can dissolve the oxidised 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, not easily hydrolysed, and not 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 a hexavalent chelating complex, with calcium ion in particular. Therefore, HEDP has good antiscale and threshold effects. When built together with other water treatment chemicals, it shows good synergistic effects.
Application
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, fertiliser, etc.. In light woven industry, HEDP is used as detergent for metal and nonmetals.
In the textile industry HEDP is used as peroxide stabiliser 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.
Specification
| Appearance (25oC) | Clear, Colorless to Pale Yellow Aqueous Solution |
| Active Content | 58-62% |
| Phosphorous Acid (as PO3 3-) | ≤2% |
| Phosphoric Acid (as PO4 3-) | ≤0.8% |
| Chloride (as Cl-) | ≤100 ppm |
| Density (20oC) | 1.43-1.47 g/cm3 |
| Fe | ≤20 mg/L |
| Color APHA (Hazen) | ≤40 |
| Ca Sequestration | ≥500 mg CaCO3/g |
| pH 1% in Water | ≤2 |
