Sodium metaphosphate CAS 10361-03-2

Sodium metaphosphate, molecular formula NaPO3, molecular weight 101.96, often exists in the form of (NaPO3)6 sodium hexametaphosphate (also known as “Gremium salt”) polymer. Density (20℃) 2.484g/cm3, melting point 640℃. Heat of generation-1206.3kJ/mol. Phosphoric anhydride and soda ash according to the ratio of 1:0.8 in the stirrer after mixing, into the graphite crucible, at a temperature of 750 ° C-850 ° C temperature for melting polymerization, quickly taken out of the cooling tray in the quench that is obtained after sodium hexametaphosphate. Or the anhydrous sodium dihydrogen phosphate after drying and dehydrating is heated in the graphite crucible at 700-800℃, the processing time is about 1h-1.5h, and then quickly taken out and quenched in the cooling plate to get sodium hexametaphosphate. Transparent glass flakes or white granular crystals. The solubility in water is large, but the dissolution rate is slow, and the aqueous solution is acidic reaction. It is easily hydrolyzed into orthophosphate in warm water, acid or alkali solution. Sodium hexametaphosphate is hygroscopic and starts to become sticky after absorbing moisture. For some metal ions (such as calcium, magnesium, etc.) have the ability to generate soluble complexes, so it can be used to soften water. With lead, silver and other ions will also generate a precipitate, these precipitates dissolve in excess of sodium hexametaphosphate solution to form complexes, barium salt can also be generated with sodium hexametaphosphate complexes. It is used as high efficient water softener for power station, boiler water for rolling stock, auxiliary agent for detergent, agent for controlling or preventing corrosion, cement hardening accelerator, streptomycin purifier, cleaning agent for fiber industry, bleaching and dyeing industry. It is used as sedative in medicine, preservative, stabilizer and juice precipitant in food industry. In the petroleum industry, it is used for antirust of drilling pipe and controlling the viscosity of mud when oil drilling. It is also used in fabric printing and dyeing, tanning, papermaking, color film, soil analysis, radiochemistry and analytical chemistry.