Molar mass: 611.77 g·mol-1 Appearance: white, odorless, crystalline powder
Density: 2.484 g/cm3
Melting point: 616°C (Decomposition)
Boiling point: 1500 °C
Solubility (water): easily soluble
Solubility (organic solvent): insoluble
Hygroscopicity: Strong, easily hydrolyzed to orthophosphate in warm water, acid or alkali solution.
Other properties:
1. Melting point 616°C (decomposition), relative density 2.484g/cm3 (20°C), easily soluble in water, insoluble in organic solvents. Colorless transparent glass flakes or white granular crystals. It is highly hygroscopic and can gradually absorb moisture when exposed to the air and become a sticky substance. It can form soluble complexes with metal ions such as calcium and magnesium.
2. Neutralize reaction between soda ash or caustic soda solution and phosphoric acid. After completion, continue to heat to 250°C to generate sodium metaphosphate, then heat to 620°C to melt and polymerize into the original crystal, and then quench and tablet. (pelletizing). Food-grade sodium hexametaphosphate needs to be purified to remove arsenic and heavy metals after the neutralization reaction is completed, and then heated and roasted to obtain it. Used in the manufacture of water treatment agents, corrosion inhibitors, metal surface treatment agents, cement hardening accelerators, coated paper slurry diffusion agents and oil drilling, etc. Food grade, mainly used as quality improver, chelating agent, fermentation leavening agent, pH regulator, etc.