Hydroxyethylidene diphosphonic acid (HEDP)

Hydroxyethylidene diphosphonic acid (HEDP)

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CAS No.2809-21-4


Synonym: hydroxyethylene diphosphonic acid HEDPA (1-hydroxyethylene) diphosphonic acid 1-hydroxyethylene-1,1-diphosphonic acid


Molecular formula: C2H8O7P2 Relative molecular mass: 206.02


Structural formula 


1. Performance and usage

HEDP is an organic phosphonic acid scale and corrosion inhibitor, which can form stable complexes with iron, copper, zinc and other metal ions, can dissolve the oxides on the metal surface. It can still play a good role in corrosion and scale inhibition at 250 °C, and it is still very stable at high pH, not easy to be hydrolyzed, and not easy to decompose under general photothermal conditions. The acid and alkali resistance and chlorine oxidation resistance are better than other organic phosphonic acids (salts). It can form a six-ring chelate with metal ions in water, especially calcium ions, so it has good scale inhibition effect and obvious solubility limit effect. When used in combination with other water treatment agents, it shows an ideal synergistic effect. .

The solid is a high-purity product, suitable for cold winter areas; especially suitable for cleaning agents and daily chemical additives in the electronic industry.

Widely used in electric power, chemical industry, metallurgy, chemical fertilizer and other industrial circulating cooling water systems, as well as scale and corrosion inhibition of medium and low pressure boilers, oilfield water injection and oil pipelines; In the textile industry, it can be used as a cleaning agent for metals and non-metals. Also it is peroxide stabilizers and fixatives for bleaching and dyeing industries, complexing agent in cyanide-free electroplating industry, and carrier of radioactive elements in pharmaceutical industry.

Specifications

Items

Standards

 

GB/T 26324-2010

——

HG/T3537-2010

Appearance

 

Colorless or light yellow transparent liquid

White crystalline particles

Active ingredient (calculated as HEDP) %

50.0

60.0

90.0

Phosphorous acid (as PO33-) %

2.0

2.0

0.8

Phosphoric acid (as PO43-) %

0.8

0.8

0.5

Chloride (as Cl-) %

0.02

0.02

0.01

pH (1% aqueous solution)

 

1.5-2.0

1.5-2.0

1.5-2.0

Iron (as Fe2+) content mg/L

20

20.0

10.0

Density(20℃)g/cm3

1.36

1.40

——

Calcium Chelation Value mg/L

450

500

--

Active ingredient (calculated as HEDP·H2O) %

 

--

--

≥97

 

Using method:

As a scale inhibitor, the concentration is generally 1-10mg/L; as a corrosion inhibitor, the concentration is generally 10-50mg/L; as a cleaning agent, the concentration is generally 1000-2000mg/L; usually used in conjunction with a polycarboxylate scale inhibitor and dispersant . When used in other industries, the dosage should be determined according to the test.

packaging and storage:

Liquid are packed in plastic barrels, 30KG or 250KG per barrel; solids are packed in plastic woven bags lined with polyethylene bags, with net weight of 25KG per bag, can also be custom-made according to user needs. Stored in a cool and ventilated indoor place, moisture-proof, valid for twelve months.

safety protection

This product is acidic, pay attention to labor protection during operation, avoid contact with skin, eyes, etc., and immediately rinse with plenty of water after contact.

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