Southerly fine hexametaphosphate English name: Sodium Hexametaphosphate (Sodium Polyphosphates, Glassy; Sodium Tetrapolyphosphate; Graham’s Salt) English shorthand: SHMP Alias: Sodium vitreous, four sodium tripolyphosphate, Graham salt of the formula: (NaPO3) 6 (Mr≈611.77) CAS no .: 10124-56-8 appearance: transparent flake or powder basic properties of glass molar mass: 611.77 g · mol 1 appearance:? white, odorless, crystalline powder density: 2.484 g / cm3 melting point : 550 ° C Boiling point: 1500 ° C solubility (water): soluble solubility (organic solvents): insoluble other properties: 1, melting point 616 ℃ (decomposition), the relative density of 2.484g / cm3 (20 ℃), soluble in water, insoluble in organic solvents. Colorless transparent glass flake or white granular crystals. Hygroscopicity strong, exposed in air gradually absorb moisture was glue substance. With calcium, magnesium and other metal ions can generate soluble complexes. 2, or by the caustic soda solution and phosphoric acid neutralization reaction, after the completion of heating was continued to 250 ℃, generate partial sodium phosphate, then heated to 620 ℃ melt polymerization and the cost of the grain, the quench producer (pressure tablets) system. Food grade sodium hexametaphosphate is required after the completion of the reaction and removal of arsenic, heavy metals, etc. in addition to purification, re-heating and melt system. For the manufacture of water treatment agents, corrosion inhibitors, metal surface treatment agent, cement hardening accelerator, coated slurry spreading agent and oil drilling and the like. Food grade, mainly used as quality improver, chelating agents, fermentation leavening agent, pH adjusting agent.