1-Hydroxy Ethylidene-1,1-Diphosphonic Acid/HEDP / CAS 2809-21-4

CAS No.:

2809-21-4

Molecular Formula:

C2H8O7P2

Molecular weight:

206.02

Usage:

HEDP is used as scale and corrosion inhibition in circulating cool water systems, oil fields and low-pressure boilers in fields such as electric power, chemical industry, metallurgy, fertilizer, etc.. In light weaved industry, HEDP is used as a detergent for metal and nonmetal. In the dyeing industry, HEDP is used as a peroxide stabilizer and dye-fixing agent; In non-cyanide electroplating, HEDP is used as the 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.

Properties:

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 values, is 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 ions in particular. Therefore, HEDP has good antiscale and visible threshold effects. It shows good synergistic effects when built together with other water treatment chemicals.

The solid state of HEDP is crystal powder, suitable for usage in winter and freezing districts. Because of its high purity, it can be used as cleaning agent in electronic fields and as additive in daily chemicals.

Specification:

Items

Result

Appearance

Colorless Transparent Liquid solution

Active content (HEDP)%

60.50%

Phosphorous acid (as PO₃^3-)%

0.90%

Phosphoric acid(as PO₄^3-)%

0.20%

PH (1% water solution)

1.6

Density(20℃)g/cm³

1.451

Chloride（Cl^-）

24ppm

Iron (Fe²⁺)

5ppm

Package and Storage:

HEDP liquid: Normally In IBC drum can also be used as required.

Storage for ten months in room shady and dry place.

Safety Protection:

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