Preparation method for food grade disodium hydrogen phosphate

Abstract

The invention relates to a preparation method for food grade disodium hydrogen phosphate, which comprises the following steps of: (1) dissolving sodium hydroxide in deionized water with stirring, and filtering for later use; (2) adding deionized water, phosphoric acid and a decolorizer into a reactor in turn, slowly adding the solution in the step (1), stopping adding the materials when the pH value of the system is between 3.5 and 4, keeping the system temperature, and continuing stirring for 40 to 60 minutes; and (3) standing the reaction liquid overnight, adding the reaction liquid into a concentrating kettle, heating the reaction liquid with uniform stirring until boiling, maintaining the boiling of the system, stopping heating until the volume of the reaction liquid is half of the original volume, naturally cooling with stirring until all crystals in the solution are precipitated, filtering and separating the crystals from crystallization mother liquor, naturally drying the obtained colorless crystals in the shade, and packing for sale. In the method, the best reaction proportion of various reactants of phosphoric acid and sodium hydroxide is determined by comparing and researching the synthesizing processes of the food grade disodium hydrogen phosphate, so that the reaction yield is improved, and the method is more suitable for industrial production.

Description

technical field [0001] The invention belongs to the field of organic compound preparation, in particular to a preparation method of food-grade disodium hydrogen phosphate. Background technique [0002] Food-grade sodium dihydrogen phosphate is colorless crystal or white crystalline powder, odorless, salty, sour, slightly deliquescent and widely used. Mainly used in: 1. Industrial field; used for boiler water treatment, acidity buffer, detergent, baking powder, mica sheet bonding, dye auxiliaries, tanning, electroplating, etc., and is also used for making acid sodium pyrophosphate and six Raw material of sodium metaphosphate; 2. Food field: used as buffer, emulsifier, nutrient, etc. in food and beverage; 3. Pharmaceutical field: it is a medicine for regulating water, salt, electrolyte and acid-base balance, suitable for low phosphorus It is also used as a phosphorus supplement for total intravenous hypertrophic nutrition therapy to prevent hypophosphatemia, prevent calcium-c...

AI Technical Summary

Problems solved by technology

[0003] However, the food-grade disodium hydrogen phosphate prepared by the existing process is relatively complicated, and the more important thing is that the yield is low, which affects the wide use of food-grade disodium hydrogen phosphate