Separation and purification method of disodium hydrogen phosphate

The invention discloses a method for separating and purifying disodium hydrogen phosphate, which comprises the following steps: taking phosphate solid, adding water, heating until the phosphate solid is completely dissolved, cooling, adding activated carbon, stirring for a period of time, filtering, adjusting the pH value of the filtrate to 8.8-9.2 by using an alkaline solution with proper concentration at a proper temperature, and filtering to obtain the disodium hydrogen phosphate. And cooling and crystallizing at 4-10 DEG C for a period of time, and filtering to obtain white crystals which are qualified products meeting industrial standards. According to the present invention, the phosphate solid purification process is subjected to comparative research, such that the use amount of the solvent water, the stirring temperature during pH adjustment, the pH value and other optimal parameter ranges are determined so as to make the product purity meet the industrial grade standard; 本发明公开了一种磷酸氢二钠的分离纯化方法，所述分离提纯的方法