Synonyms: HEDP(A);HEDPA; Etidronic Acid; 1-Hydroxy-1,1-Ethanediyl Ester; Dequest 2010; Mayoquest 1500; Beleclene 660; Briquest ADPA-60A; Unihib 106; Excel Codex 661; Sequacel HD
HEDP is mainly produced by a reaction of Phosphorus Trichloride (PCl3) and Glacious Acetic Acid (CH3COOH) in the tertiary amine. Besides, some plants also use another continuous process to synthesize HEDP by Phosphorous Trichloride (PCl3) and Acetyl chloride (CH3COCl).
CAS No.: 2809-21-4
Molecular Formula: C2H8O7P2
Molecular weight: 206.02
HEDP 60 is an excellent corrosion inhibitor and antiscalant. HEDP 60% can dissolve the oxidized materials on these metals’ surfaces. It shows excellent scale and corrosion inhibition effects under temperature 250℃.
Under high pH value and/or 250℃, HEDP 60% shows good chemical stability. It is difficult to be decomposed by normal light and heat conditions. Actually, its tolerance to acid, alkali and chlorine oxidation is better than most of the other organophosphonates.
HEDP can react with metal ions in the water system to form a hexa-element chelating complex. It can chelate with Ba, Pb, Fe, Zn, Cu ion and especially Ca ions. Therefore, HEDP 60 has good antiscale and visible threshold effects. The oxidate on these metal surfaces will be dissolved by HEDP. Synergy will be achieved when HEDP is built with other WT chemicals, usually polycarboxylic acid.
Besides liquid, HEDP solid is offered in crystal powder for freezing regions, especially in winter. Because of HEDP solid is high purity, it can be used as a cleaning agent in electronic fields and as additives in daily chemicals.
|Appearance||Clear, Colorless to pale yellow aqueous solution||White crystal powder|
|Active content (HEDP)%||58.0-62.0||90.0 min|
|Phosphorous acid (as PO33-)%||2.0 max||0.8 max|
|Phosphoric acid (asPO43- )%||0.8 max||0.5 max|
|Chloride (as Cl-) %||0.01 max||0.01 max|
|pH (1% solution)||2.0 max||2.0 max|
|Density (20℃)g/cm3||1.40 min||–|
|Fe，mg/l||10.0 max||5.0 max|
|Colour APHA (Hazen)||40.0 max||–|
HEDP 60 is used as scale and corrosion inhibition in circulating cool water system, oil field and low-pressure boilers in fields. HEDP is widely used power station, oil fields, chemical plants, metallurgic plant for cooling water system and boilers as scale inhibitor with preferred dosage 1-10mg/L (antiscalant) and 10-50mg/L (corrosion inhibitor).
In the daily chemical industry, HEDP is used as metal and nonmetal detergent. Dosage is usually 1,000-2,000mg/L. It is also a peroxide stabilizer and dye-fixing agent in the dyeing industry.
Usually, HEDP acid chemicals are used together with the polycarboxylic acid.
HEDP is widely used power station, oil fields, chemical plants, metallurgic plant for cooling water system and boilers as scale inhibitor with preferred dosage 1-10mg/L (antiscalant) and 10-50mg/L (corrosion inhibitor)
Package and Storage:
Liquid: 200L plastic drum, IBC (1000L), customers’ requirement.
Solid: 25kg/bag, customers’ requirement.
Storage for ten months in a shady room and dry place.
Acidity, avoid contact with eye and skin. Once contacted, flush with water.
IMO class 8, UN 3265.