Preparation method of strontium hydrogen phosphate

Abstract

The invention provides a preparation method of strontium hydrogen phosphate. The preparation method comprises the following steps: adding a hydrophosphate-dihydric phosphate buffer solution with a pH value of 6-9 to a reactor, and then adding a strontium hydroxide solution and a phosphoric acid solution, which have the equal molar concentration, to the reactor in an equal flow rate manner; enabling the volume ratio of the buffer solution, the strontium hydroxide solution and the phosphoric acid solution to be 1:1:1; performing reaction on strontium hydroxide with phosphoric acid to generate strontium hydrogen phosphate, wherein the reaction temperature is normal temperature, and the reaction time is 1 hour; after the reaction, performing centrifugal separation on the reaction solution, and precipitating and drying to obtain the strontium hydrogen phosphate product; recovering the supernatant after membrane concentration, and preparing the buffer solution to be reused from the supernatant. According to the preparation method disclosed by the invention, strontium hydroxide is used for substituting strontium nitrate or strontium chloride in the conventional technology, and phosphoric acid is used for substituting ammonium hydrogen phosphate to produce strontium hydrogen phosphate; the preparation method is simple in production process; the product is free of entrained chloride ions and nitrate ions, high in purity, and controllable in grain size; the preparation method is low in cost and free of ammonia nitrogen waste liquid discharge.

Description

technical field [0001] The invention belongs to the technical field of trichromatic fluorescent powder raw materials for lamps, and in particular relates to a method for preparing strontium hydrogen phosphate by using strontium hydroxide and phosphoric acid. Background technique [0002] As the main phosphor raw material, strontium hydrogen phosphate has a very large market prospect. However, the current traditional method for producing strontium hydrogen phosphate mostly uses strontium nitrate or strontium chloride as the main raw material, and reacts with hydrogen phosphate to generate strontium hydrogen phosphate; the strontium hydrogen phosphate prepared by this method is easy to entrain chloride ions or nitric acid in the product root ions, the purity is low; and there is still a problem that the particle size is difficult to control in the production process, and the particle size of the product is prone to change during the washing process, which makes the particle ...

AI Technical Summary

Problems solved by technology

[0003] Aiming at the above-mentioned deficiencies in the prior art, the present invention aims at the technical problems of low purity of strontium hydrogen phosphate obtained by the traditional preparation method, difficulty in controlling particle size, low product quality, and easy environmental pollution; and provides a simple and clean A method for preparing strontium hydrogen phosphate, the strontium hydrogen phosphate prepared by the method has high purity and uniform particle size