Preparation
 By the dehydration of disodium hydrogen phosphate formed by melt water pyrophosphate, soluble in water crystallization in the system.

 Uses:
 Electroplating industry for the preparation of plating solution, contact table with iron to form objects. Wool and wool textile industry as a degreasing agent and bleaching hair agent. Paper and paper industry for bleaching plant fiber. Printing and dyeing industry as dyeing, bleaching, when the additives fine. Japanese chemical additives for toothpaste, gel formation with calcium hydrogen phosphate, and play a stabilizing role, but also for production of synthetic detergent and shampoo ointment products. Water as a water softener. Machining as a rust remover. Chemical production as dispersants and emulsifiers. Can also be used for water treatment, oil drilling, etc., in the food industry as a quality improver, emulsifier, buffer, chelating agents, etc.

 Sodium pyrophosphate have soft water features, can be dissolved calcium, magnesium and insoluble salts, such as clothing fibers, mixed live insoluble calcium soap or other metal soap formation of dirt, it can improve its decontamination and then dissolved capacity. In addition, sodium pyrophosphate with anti-flocculation, so that oil from the emulsion, which is called peptization properties. Surfactant solution can also further reduce the surface tension and interfacial tension, play a role in washing to help wash.