Sodium Hexametaphosphate (SHMP)

About This Product

Sodium hexametaphosphate is a polyphosphate produced by fusing monosodium phosphate and quenching the melt rapidly, which gives a glassy amorphous solid rather than a crystalline one. It carries CAS number 10124-56-8 and is supplied as glassy plates, granules or powder that dissolve slowly but completely. Its long phosphate chain wraps around divalent cations and holds them in soluble complexes, and it does this at doses far below the stoichiometric requirement, an effect known as threshold inhibition. In practice a few parts per million in a cooling circuit is enough to distort the growing crystal faces of calcium carbonate and stop scale forming, rather than having to chelate every calcium ion present. That efficiency is why it dominates in industrial water treatment. In ceramics it does something different with the same chemistry: adsorbed onto clay particles it raises their surface charge so they repel one another, which collapses the viscosity of a slip and allows a castable slurry to be made at much lower water content. It is also used as a detergent builder, a dispersant for pigments and as a peptising agent. It is used in cooling water and boiler scale inhibition, ceramic and clay slip deflocculation, detergents, pigment dispersion, oilfield chemicals and metal treatment. Bio Green Chem supplies SHMP to specification on P2O5 content, pH, insoluble matter, fluoride, arsenic and heavy metals.