Application fields and Applications:     Electroplating grade four potassium used for non cyanide electroplating, as the plating complexing agent, is also used for surface treatment, that is used as a pretreatment agent of electroplating and electroplating solution.     Four industrial grade pyrophosphate potassium is widely used in paint, detergent, boiler removal of dirt, oil drilling, textile printing and dyeing additives, as high-grade detergent, cleaning agent, dispersing agent, buffering agent, etc. in industry, is the preparation of cloth with detergent group, metal surface cleaning agent and bottle washing agent component, various cleaning agent additives, used as a dispersing agent for industrial ceramic clay and pigment and dye dispersant and a buffering agent, bleaching and dyeing industry to remove a small amount of ferric ion in the water, improving the quality of bleaching and dyeing.     Food grade tetrapotassium pyrophosphate for processed foods, food additives, emulsifier, modifier, chelating agent, quality improvement agent, used as emulsifying agent, chelating agent in the food industry, flour products with alkali agent of raw materials; prevent discoloration of fruit canned; increasing ice cream expansion degree and ham, sausage yield; enhance fish to water, improving the surface kind of taste, improve the rate to prevent cheese aging. As complexing agent in non cyanide plating 1, Cu2+, Sn2+, Ag+, Zn2+, Ni2+, Cr3+, Ca2+ and Mg2+ have excellent complexing ability of multivalent cations; 2, to the THF solution of 10 ml1% dropwise (2.5 ml) min1% of nitric acid silver solution, resulting in a white precipitate can quickly complex synthesis of clear solution. 3, bath with excellent polarization ability and current dispersing ability, preparing plating solution without after electrolysis process for electroplating, plating plating speed fast, uniform coating, crystal structure, fine, compact and no gap, bath is stable, strong anti-interference ability and simple maintenance. 4, the fine dispersion of solid material has a strong ability to disperse; 5, stable pH buffer capacity. Determination of complexing capacity    Weighing 1 g of THF after dissolved in distilled water with constant volume to 100 ml, with 1% solution of 100 ml, 100 ml of solution drops with 1% silver nitrate solution to the, stirring to produce white sediment couldn't was completely complex check record drops with the amount of 1% silver nitrate solution (ML) is the THF complexing capability index.