Properties:

HEDP Na has two appearance status. One is a colorless or yellowish transparent liquid. And the other is powder. This HEDP phosphonate is harmless. Thus, engineers like to use it much instead to use other harmful acids.

The anti-scaling and corrosion inhibition are optimum up to 250°C. No matter at low or high pH value. HEDP Na is not easily hydrolyzed. The Cl– stability is better than that of general phosphonates.

HEDP Na is stable under high pH value. It is difficult to be hydrolyzed. And also it hard to be decayed under the light as well as thermal condition. The acid/alkaline as well as chlorine oxidation tolerance of HEDP Na is far better than that of other natural phosphonic acids.

HEDP Na can form six-ring chelating compounds with metal ions in a water system. Ca2+ in particular. HEDP sodium salt has great scale restraint results and noticeable dissolution threshold effects. When it is used with various other water treatment chemicals, the synergistic results are better.

In winter, it has an additional benefit. That is the HEDP phosphonate sodium powders do not freeze. This benefit is contrary to HEDP acidic solutions.

The HEDP Na can quickly form stable complexes with Fe, Cu, Zn ions. Therefore it can protect against the scale of these ions. The effect of anti scale and corrosion inhibition is best at 250°C. No matter at low or high pH value. HEDP Na is hard to be hydrolyzed. The Cl– stability is much better than that of other phosphonates.

Dosage:

2-20 mg/L is preferred as a scale inhibitor.

20-100mg/L is preferred as a corrosion inhibitor

1000-2000 mg/L is preferred as a cleaning agent.

Usually, HEDP Na is used together with the polycarboxylic acid.