Name: 1-Hydroxy Ethylidene-1,1-Diphosphonic Acid (HEDP)
CAS No.: 2809-21-4
Molecular Formula C2H8O7P2
Relative molecular mass: 206.02
Product Description
1. Properties and Uses
HEDP is an organophosphonic acid scale and corrosion inhibitor, which can form stable complexes with iron, copper, zinc and other metal ions, and can dissolve the oxides on the metal surface. It can still play a good role in corrosion and scale inhibition at 250ºC, and is still stable at high pH, not easy to hydrolyse, and not easy to decompose under general light and heat conditions. Acid and alkali resistance, chlorine oxidation resistance is better than other organic phosphonic acid (salt). It can form hexacyclic chelates with metal ions in water, especially calcium ions, thus it has better scale inhibition effect and obvious solubility limitation effect, and it shows ideal synergistic effect when used in combination with other water treatment agents.
HEDP solid belongs to high purity products, suitable for winter cold area; especially suitable for cleaning agent in electronics industry and additives for daily-use chemicals.
HEDP is widely used in electric power, chemical industry, metallurgy, chemical fertilizer and other industrial circulating cooling water system and medium and low pressure boiler, oil field water injection and oil pipeline scale inhibition and corrosion inhibition; in the textile industry, it can be used as metal and non-metal cleaning agent, bleaching and dyeing industry peroxide stabilizers and color-fixing agents, cyanide-free electroplating industry complexing agent, the pharmaceutical industry as a carrying agent for radioactive elements.
2. Usage
HEDP is generally used as scale inhibitor with a concentration of 1-10mg/L, as a corrosion inhibitor with a concentration of 10-50mg/L; as a cleaning agent with a concentration of 1000-2000mg/L; it is usually used in conjunction with polycarboxylic acid-type scale inhibitor and dispersant. When used in other industries, the dosage should be determined according to the test.
Product Parameters
| project |
metric |
| |
50% Liquid |
60% Liquid |
solid |
| |
GB/T 26324-2010 |
-- |
HG/T 3537-2010 |
| appearance |
Colorless or pale yellow clear liquid |
Colorless or pale yellow clear liquid |
White crystal particles |
| Active component ()/% in HEDP |
≥50.0 |
≥60.0 |
-- |
| Phosphate (in PO33-)/% |
≤2.0 |
≤2.0 |
≤0.8 |
| Phosphoric acid ()/% in PO43- |
≤0.8 |
≤0.8 |
≤0.5 |
| Chloride (in Cl-form) /% |
≤0.02 |
≤0.02 |
≤0.01 |
| PH Value (1% aqueous solution) |
1.5-2.0 |
1.5-2.0 |
1.5-2.0 |
| Density (20ºC) / gcm-3 |
≥1.36 |
≥1.40 |
-- |
| Calcium chelation value/mg·g-1 |
≥450 |
≥500 |
-- |
| Iron (measured as Fe2 +) content / mg L-1 |
≤20.0 |
≤20.0 |
≤10 |
| Active fraction ()/% in HEDP H2O |
-- |
-- |
≥97.0 |
Packaging & Shipping
3. Packing and storage
HEDP liquid is packed in plastic drum, 30Kg or 250Kg per drum; HEDP solid is packed in plastic woven bag lined with polyethylene bag, net weight 25kg per bag, or according to user's need. Stored in a cool and ventilated place, moisture-proof, storage period of twelve months.
4. Safety Protection
HEDP is acidic, pay attention to labour protection during operation, avoid contact with skin, eyes, etc., and flush with plenty of water immediately after contact.
Company Profile
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