Method for preparing high-purity stannous pyrophosphate

Abstract

The invention relates to a method for preparing high-purity stannous pyrophosphate. The method comprises the following steps of using water with air removed to respectively dissolve soluble stannous salt and soluble pyrophosphate, vacuumizing to remove air in solution and a reactor, controlling the temperature to be between 50 and 80 DEG C, and under stirring, mixing the two kinds of raw material solution to react; then sealing the reactor, cooling the reactant to room temperature, filtering the reactant, washing the deposit, and centrifuging the deposit to dry the deposit; and adding the deposit into water to disperse the deposit, pumping the air, controlling the temperature to be between 50 and 80 DEG C, stirring, washing, cooling the reactant to room temperature, filtering andcentrifuging the deposit to dry the deposit, and drying the deposit in vacuum to obtain a high-purity white powered stannous pyrophosphate product. The stannous pyrophosphate content in the stannous pyrophosphate product is greater than 99 percent. The stannous pyrophosphate prepared by the method is high in purity, large in crystalline grains and easy to wash. The method is simple and convenient to popularize and use.

Description

technical field [0001] The invention relates to a method for preparing stannous pyrophosphate, in particular to a method for preparing high-purity stannous pyrophosphate. Background technique [0002] Stannous pyrophosphate is mainly used in electroplating industry and toothpaste manufacturing industry, but also in paint industry, printing and dyeing industry, leather manufacturing industry and food industry. The current method for preparing stannous pyrophosphate is to use stannous chloride or stannous sulfate to undergo metathesis reaction with alkali metal pyrophosphate to generate insoluble stannous pyrophosphate precipitate, which is washed, filtered and dried to obtain pyrophosphate For tin products, such as the patent application whose publication number is CN101234757A and titled "Method for preparing stannous pyrophosphate", because the soluble stannous ion used in the preparation process is easily oxidized by air, the content of tetravalent tin in stannous pyrophos...

AI Technical Summary

Problems solved by technology

The current method for preparing stannous pyrophosphate is to use stannous chloride or stannous sulfate to undergo metathesis reaction with alkali metal pyrophosphate to generate insoluble stannous pyrophosphate precipitate, which is washed, filtered and dried to obtain pyrophosphate For tin products, such as the patent application whose publication number is CN101234757A and titled "Method for preparing stannous pyrophosphate", because the soluble stannous ion used in the preparation process is easily oxidized by air, the content of tetravalent tin in stannous pyrophosphate products It is too high, and the tin ion is easy to hydrolyze, forming precipitated impurities that are not easy to be washed and removed, resulting in large turbidity of the stannous pyrophosphate product, and the stannous pyrophosphate crystal grains generated in the preparation process are finer, with many impurities entrained, and difficult to filter. Difficult to wash, resulting in a large amount of washing water and low product purity