1-Hydroxyethylidene-1,1-Diphosphonic Acid (HEDP)

Phosphonate scale & corrosion inhibitor · 60% liquid / 90% solid

Description

An organophosphonic acid known for excellent CaCO₃ scale inhibition and chlorine stability. Forms stable chelates with Fe, Cu and Zn — a workhorse of cooling water treatment.

CAS 号2809-21-4

分子式C2H8O7P2

分子量206.03

外观无色至淡黄色透明液体 / 白色结晶粉末

含量60% 液体 / 90% 固体

Technical Data

项目	HEDP-60	HEDP-90
外观	无色至淡黄色透明液体	白色结晶粉末
活性组分（HEDP）%	58.0–62.0	≥90.0
亚磷酸（以 PO₃³⁻ 计）%	≤1.0	≤0.8
磷酸（以 PO₄³⁻ 计）%	≤0.6	≤0.5
氯化物（以 Cl⁻ 计）ppm	≤100	≤100
pH 值（1% 溶液）	≤2.0	≤2.0
密度（20 ℃）g/cm³	1.43–1.47	—
铁（Fe）mg/L	≤10.0	≤5.0
色度（APHA）	≤40	—

Key Properties

Stable at temperatures up to 250 °C, retaining scale and corrosion inhibition
Chemically stable and hydrolysis-resistant at high pH
Superior resistance to acid, alkali and chlorine oxidation compared with most phosphonates
Forms six-membered chelates with calcium ions; exhibits threshold effect
Pronounced synergies when blended with other water treatment chemicals

Applications

Scale and corrosion inhibition in cooling water, boiler water and oilfield injection water
Metal ion chelating agent in textile dyeing and printing
Metal surface treatment and electronics cleaning
Chelating component in detergents and household chemical formulations

Packaging & Storage

Packaging: Liquid: 250 kg or 30 kg drum, 1000 L IBC available. Solid: 25 kg PE-lined woven bag.

Storage: Store sealed in a cool, dry place. Liquid: ten months. Solid: two years. Avoid direct contact with strong alkali.

Handling & Safety

Acidic and corrosive. Wear goggles, acid-resistant gloves and protective clothing.

1-Hydroxyethylidene-1,1-Diphosphonic Acid (HEDP)