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

CAS No. 7414-83-7 EINECE NO. 700-903-6
Molecular Formula C2H6O7P2Na2 Molecular Weight 250
Structural Formula

HEDP.Na2 Structural Formula

Product Features

HEDP.Na2 is based on the dissodium salt form of HEDP (1-Hydroxy Ethylidene-1,1-Diphosphonic Acid).

HEDP.Na2 is an excellent organophosphonic acid corrosion inhibitor.

HEDP.Na2 can chelate with Fe, Cu, and Zn ions. HEDP.Na2 can dissolve the oxidized materials.

HEDP.Na2 has good scale and corrosion inhibition effects even under 250℃.

HEDP.Na2 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•Na2 has good scale inhibition effects and obvious dissolution threshold effects. When used with other Water Treatment Chemicals, the synergistic effects is better.

Technical Specification

Items Index
Liquid Solid
Appearance Colorless to light yellow transparent liquid White powder
Active component(HEDP), % 16.5min 74.0-79.0
Active content(HEDP•Na2), % 20.0 min 89.8 min
Density (20℃), g/cm3 1.12-1.22 --
Fe, mg/L -- 20 max
Phosphorous acid (PO33-), % -- 3 max
Moisture, % -- 3.0-6.0
PH (1% water solution) 4.0-6.0 4.0-6.0

Applications & Usage

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•Na2 is used as peroxide stabilizer and dye-fixing agent.

In non-cyanide electroplating, HEDP•Na2 is used as chelating agent.

Applications & Usage

ATMP.Na4 is mostly used with organophosphoric acid, polycarboxylic acid and salt to form all organic water treatment formulation for various circulating cooling water systems with different water quality conditions. Neutralized form and has excellent CaCO3 scale inhibitor in oilfield applications. Compatible with other additives.

Scale and Corrosion inhibition Performance

CaCO3 inhibition CaSO4 inhibition Ca3(PO4)2 inhibition BaSO4 inhibition CaF2 inhibition
Excellent Poor Very Good Good Good
Calcium Tolerance Iron Control Sequestration Steel corrosion inhibition
Poor Yes Good Very Good

Package & Storage

HEDP.Na2 Solid HEDP.Na2 Liquid
25kg Bag Bulk Bag 25L Drum 200L Drum 1000L IBC ISO Tank
Once contacted with eye and skin, flush with plenty of clean water.

Hazard & Safety Precaution

Hazard Information Safety Precaution

Not regulated

Once contacted with eye and skin, flush with plenty of clean water

Alternative Name / Synonyms

  1. Disodium Etidronate Hydrate;
  2. Disodium dihydrogen bisphosphonate (1-hydroxyethylidene)bisphosphonate

HEDP.Na2 related products :

  1. Disodium Salt of 1-Hydroxy Ethylidene-1,1-Diphosphonic Acid
  2. Tetra Sodium Salt of 1-Hydroxy Ethylidene-1,1-Diphosphonic Acid (HEDP•Na4)
  3. 1-Hydroxy Ethylidene-1,1-Diphosphonic Acid (HEDP)