Specification :

HEDP (1-Hydroxy Ethylidene-1,1-Diphosphonic Acid)

CAS No. 2809-21-4
Dequest:2010
HEDP is an organophosphoric acid corrosion inhibitor. HEDP can chelate with Fe, Cu, and Zn ions to form stable chelating compounds. HEDP can dissolve the oxidized materials on these metals surfaces. HEDP shows excellent scale and corrosion inhibition effects under temperature 250centigrade. 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.
The solid state of HEDP is crystal powder, suitable for usage in winter and freezing districts. Because of its high purity, HEDP can be used as cleaning agent in electronic fields and as additives in daily chemicals.

Specification of HEDP:
Appearance of HEDP: Colorless or light yellow transparent liquid White crystal powder
Active content of HEDP (HEDP): 58.0-62.0percent 89.0 percent min
Phosphorous acid of HEDP (as PO33-): 2.0 percent max 0.5 percent max
Phosphoric acid of HEDP (as PO43- ): 0.8 percent max 0.5percent max
Chloride of HEDP (as Cl-): 0.01 percent max 0.01 percent max
pH of HEDP (1percent solution): 2 max 2 max
Density of HEDP (20 centigrade): 1.40 g/cm3 -
Fe ion of HEDP ppm: 10 max 20 max
Colour APHA (Hazen): 40 max -

Usage of HEDP:
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.

Package and Storage of HEDP:
HEDP liquid: Normally In 250kg net Plastic Drum, IBC drum can also be used as required HEDP solid: 25kg inner liner polyethylene (PE) bag, outer plastic woven bag, or confirmed by clients.
Storage for ten months in room shady and dry place.