Name | Sodium metaphosphate |
Synonyms | sporix SODIUM M-PHOSPHATE Sodium metaphosphate sodiumphosphate[napo3] SODIUM HEXAMETAPHOSPHAT SODIUM PHOSPHATE, PH 6.8 sodiummetaphosphate[napo3] polymericsodiummetaphosphate phosphate glass practical grade |
CAS | 10361-03-2 |
EINECS | 233-782-9 |
InChI | InChI=1/Na.HO3P/c;1-4(2)3/h;(H,1,2,3)/q+1;/p-1 |
Molecular Formula | NaO3P |
Molar Mass | 101.96 |
Density | 2.181 |
Melting Point | 600 °C |
Solubility | 1000g/l |
PH | 5.7 (10g/l, H2O, 20℃) |
Storage Condition | Store at +5°C to +30°C. |
Physical and Chemical Properties | Sodium metaphosphate, molecular formula NaPO3, molecular weight 101.96. It is often present in the form of a polymer of (NaPO3)6 sodium hexametaphosphate (also known as "Graves' salt"). Density (20 degrees C) 2.484g/cm3. Melting point 640 °c. Heat of formation -1206.3 kJ/mol. The phosphoric anhydride and soda ash are mixed in the stirrer according to the ratio of 1:0.8, then the mixture is put into the graphite crucible, and the melting polymerization is carried out at the temperature of 750 ℃-850 ℃, sodium hexametaphosphate was obtained after rapid removal and quenching in a cooling tray. Or the anhydrous sodium dihydrogen phosphate after drying and dehydration is heated in a graphite crucible at a temperature of 700-800 ℃ for about 1 h-1.5 h. The sodium hexametaphosphate is quickly taken out and quenched in a cooling tray to obtain sodium hexametaphosphate. Transparent glass flake or white granular crystals. The solubility in water is large, but the dissolution rate is slow, and the aqueous solution is acidic. In warm water, acid or alkali solution easily hydrolyzed into orthophosphate. Sodium hexametaphosphate has strong hygroscopicity and begins to become sticky after moisture absorption. For some metal ions (such as calcium, magnesium, etc.) have the ability to form soluble complexes, it can be used to soften water. And lead, silver plasma will also produce precipitation, these precipitation complex dissolved in excess of sodium hexametaphosphate solution to form a complex, barium salt can also form a complex with sodium hexametaphosphate. It is used as a high-efficiency water softener for power station, locomotive and vehicle boiler water, an auxiliary agent for detergent, an agent for controlling or preventing corrosion, a cement hardening Accelerator, a streptomycin purifying agent, and a cleaning agent for fiber industry and bleaching and dyeing industry. It is used as a sedative in medicine and as a preservative, stabilizer and fruit juice precipitant in the food industry. In the petroleum industry, it is used for rust prevention of drill pipes and for controlling the viscosity of mud in oil drilling. In the fabric printing and dyeing, tanning, paper making, color film, soil analysis, radiation chemistry and analytical chemistry and other departments also have a certain use. |
Use | Used as a water softener |
WGK Germany | 1 |
RTECS | OY3750000 |
HS Code | 2835 39 00 |
Toxicity | LD50 orally in Rabbit: > 2000 mg/kg |
A macromolecular long-chain polyphosphate having a high degree of polymerization has a composition similar to that of metaphosphate. The average value of 72 for most of these salts is usually in the range of 500 to 1000. This long-chain polyphosphate is often referred to as metaphosphate because its NA20/P2 0s molar ratio is measured to be close to 1. After the formal determination of the partial phosphate refers to the cyclic structure of the compound. The long-chain crystalline polyphosphate sodium salt is generally referred to as the high temperature type (NaP03-II), the low temperature type (NaP03-III), and the three variants (NaPO3-IX) of the salt. White crystalline powder. Soluble in inorganic acid, potassium chloride and ammonium chloride solution. Practically insoluble in water. A (1:3) slurry was prepared in water with a pH of about 6.5.
sodium dihydrogen phosphate method: The edible sodium dihydrogen phosphate is heated, dehydrated at 95 ℃ to become anhydrous sodium dihydrogen phosphate, and then sent into the box type polymerization furnace to heat and melt polymerization, when the material temperature is 140~200 ℃, first, it is converted into sodium acid pyrophosphate, and then it is converted into cyclic sodium metaphosphate when heated to 260 ℃. After cooling and crushing, the edible sodium metaphosphate product is prepared.
used as emulsifier, tissue improver and chelating agent in food industry.
ADIO ~ 70mg/kg (in P2 OS). Generally Recognized As Safe (U. S. Food and Drug Administration, 1985). Packaging and storage refer to edible potassium metaphosphate.
EPA chemical information | Information provided by: ofmpub.epa.gov (external link) |
use | as water softener |
category | corroded articles |
acute toxicity | abdominal injection-mouse LD50: 830 mg/kg |
flammability hazard characteristics | flammability in case of h-hole agent |
storage and transportation characteristics | warehouse ventilation and low temperature drying; Store separately from H-hole agent and alkali. |
fire extinguishing agent | sand, mist water. |
toxic substance data | information provided by: pubchem.ncbi.nlm.nih.gov (external link) |