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Disodium of 1-Hydroxy Ethylidene-1,1-Diphosphonic Acid (HEDP•Na2)

CAS No.  7414-83-7

Molecular Formula: C2H6O7P2Na2       Molecular weight: 250

 Structural Formula:

Disodium of 1-Hydroxy Ethylidene-1,1-Diphosphonic Acid (HEDP•Na2)


HEDP•Na2 is an organophosphonic acid corrosion inhibitor, it can chelate with Fe, Cu, and Zn ions, it can dissolve the oxidized materials, it has good scale and corrosion inhibition effects even under 250℃, it is stable under high pH value, not easy to be hydrolyzed, not easy to be decomposed under normal light and heat condition, its acid/alkaline and chloride oxidation tolerance are better than that of other organophosph-onic acids. HEDP•Na2 can form six-ring chelating compounds with metal ions in water system, Ca2+ in particular. HEDP•Na2has good scale inhibition effects and obvious dissolution threshold effects. When used with other Water Treatment Chemicals, the synergistic effects is better.


Items Index
Appearance Colorless to light yellow transparent liquid White powder
Active content (HEDP) % 16.5 min 74.0-79.0
Active content (HEDP•Na2) % 20.0 min 89.9-95.8
Density (20℃)g/cm3 1.12-1.22 --
Fe, mg/L -- 20.0 max
Moisture,% -- 3.0-6.0
PH (1% water solution) 4.0-6.0 4.0-6.0


HEDP•Na2 is widely used in circulating cool water system, medium and low pressure boiler, oil field water pipelines as scale and corrosion inhibitor in fields such as electric power, chemical industry, metallurgy, fertilizer, etc.. In light woven industry, HEDP•Na2 is used as detergent for metal and nonmetal. In dyeing industry, HEDP•Na2is used as peroxide stabilizer and dye-fixing agent; In non-cyanide electroplating,HEDP•Na2is used as chelating agent.

Package and Storage:

Liquid: 200L plastic drum,IBC(1000L),customers’ requirement. Storage for twelve months in shady room and dry place.

Weak acidity, Avoid contact with eye and skin, once contacted, flush with water. 

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