How does a polyphosphate filter work
27 Mar.,2025
Crystal Silicon Polyphosphate scale inhibitors react with metal ions such as calcium (Ca ) and magnesium (Mg ) in water, forming soluble complexes through chelation, which inhibits the formation of calcium carbonate and magnesium carbonate, dispersing them into the water.
Crystal Silicon Polyphosphate scale inhibitors react with metal ions such as calcium (Ca ) and magnesium (Mg ) in water, forming soluble complexes through chelation, which inhibits the formation of calcium carbonate and magnesium carbonate, dispersing them into the water. While chelating calcium and magnesium ions, the inhibitor also prevents scale formation by inducing lattice distortion and electrostatic repulsion. When reacting with iron ions, the polyphosphate scale inhibitor forms a dynamic protective film on the inner surface of pipelines, isolating oxygen in the water from contact with the metal pipe walls, thus preventing corrosion and secondary pollution.
The reactions are as follows:
Na2[Na4(PO3)6] + CaX → Na2[Na2Ca(PO3)6] + Na2X
Na2Na2Ca(PO3)6] + CaX → Na2[Ca2(PO3)6] + Na2X
(soluble complex) Fe(OH)2 + Na2[Ca2(PO3)6] → FeCa2(PO3)6 + NaOH(insoluble film)
(The reaction of magnesium ions is the same as that of calcium ions.)