Sodium Tripolyphosphate

Origin
China
CAS Number
7758-29-4
HS Code
2835.31.10

Basic Info

IUPAC Name
pentasodium triphosphate
Molecular Formula
Na5P3O10
Molecular Weight (g/mol)
367.8600
Synonyms & Trade Names
Sodium tripolyphosphate; STPP; Pentasodium triphosphate; E451
Purity / Assay (%)
94% min
Physical Form
Solid
Concentration
Pure substance
Appearance / Color
White to off-white solid
Odor
Odorless
Melting Point (°C)
622.0000
Density (g/cm³)
2.5200
Solubility in Water
Freely soluble (14.5g/100mL)
Signal Word
Warning
GHS Hazard Class
Eye irritant
H-Statements
H319
P-Statements
P264|P280|P305+P351+P338
REACH Status
Registered
Drug Precursor Status
Non-precursor
Storage Class (GHS)
13
Storage Conditions
Cool, dry; sealed; hygroscopic

Categories

Technical Document

About Sodium Tripolyphosphate
Sodium Tripolyphosphate (STPP) appears as powder or granular, melting point at 622 °C, easily soluble in water, with remarkable chelating ability to some metal ions such as Ca2+, Mg2+ ,can soften hard water, change suspension into solution, alkalescent, without causticity.
Manufacturing Process
STPP has been generally made by a process that includes the steps:
Reacting a sodium compound such as soda ash (Na2CO3) or caustic (NaOH) with either wet-process phosphoric acid or furnace-process phosphoric acid to form a reaction mixture containing monosodium phosphate (NaH2PO4) and disodium phosphate (Na4HPO4).
Precipitating and, after that removing insoluble impurities from the reaction mixture.
Heating the reaction mixture at elevated temperatures for sufficient time to thermally decompose or calcinate the two phosphates named above compounds into STPP (Na5P3O10) and to simultaneously remove water from the reaction mixture by volatilization.