White powder; Melting point 622°C; easily soluble in water; It has got salient chelating capacity to ions of Ca and Mg etc. and can soften hard water to make suspension solution become into clear solution; It has got weak alkalinity but no corrosiveness.
It is a surfactant, and has got outstanding emulsification to lubricants and fat. It has different bulk density, i.e. low density 0.35-0.5g/cm 3 , medium density 0.51-0.65g/cm3 and high density 0.66-0.9g/cm 3 . This product has two crystalline forms, namely phase I (high temperature phase) and phase II (low temperature phase). The chemical properties of the two phases are the same, and the difference between them lies in the thermostability, hygroscopicity, solubility and hydration heat when dissolving 
