Preparation method of ethylenediaminetetraacetic acid calcium disodium salt

Abstract

The invention discloses a preparation method of ethylenediaminetetraacetic acid calcium disodium salt, comprising the following steps: step 1 of firstly preparing a solvent and a calcium-containing compound, adding 1-2g of the calcium-containing compound into 160-180g of the solvent at a first stirring-up state to form a mixed solution, heating the mixed solution to 35-45 DEG C, and stirring the solution for the second time; step 2 of adding 7-9 g of ethylenediaminetetraacetic acid disodium salt into the above mixture solution and then stirring the mixture solution for the third time, simultaneously heating and refluxing the mixture solution for 1.5 h, then concentrating the heated mixture solution under reduced pressure while hot to 1/3 of the original volume, subsequently cooling the concentrated solution to the room temperature, and filtering the cooled solution; step 3 of slowly dropping 350-450ml of a crystallization solution into the filtered solution and simultaneously stirring the solution, with a large number of crystal appearing, and after the dropping process, stirring the solution for the fourth time, standing and filtering the solution, washing filter cakes with a washing solution, and finally drying the filter cakes to obtain the ethylenediaminetetraacetic acid calcium disodium salt with yield of 95%.

Description

technical field [0001] The invention provides a preparation method of calcium disodium edetate. Background technique [0002] Calcium disodium edetate (also known as calcium sodium edetate) is a complexing agent, because it can release calcium ions and unintegrate calcium ions by complexing with multivalent ions, so it can make the human body produce low calcium Reaction, widely used in food and medicine as a stabilizer. The preparation method of calcium disodium edetate has following two kinds at present: 1, take disodium edetate and calcium carbonate as raw material to synthesize, these two kinds of materials do not react, there is no reaction product, and the yield is relatively low , with a content of 78%; 2. Using disodium edetate and calcium chloride as raw materials for synthesis, the chloride is unqualified and the yield is relatively low. Contents of the invention [0003] The invention provides a preparation method of calcium disodium ethylenediamine tetraaceta...

AI Technical Summary

Problems solved by technology

The preparation method of calcium disodium edetate has following two kinds at present: 1, take disodium edetate and calcium carbonate as raw material to synthesize, these two kinds of materials do not react, there is no reaction product, and the yield is relatively low , with a content of 78%; 2. Using disodium edetate and calcium chloride as raw materials for synthesis, the chloride is unqualified and the yield is relatively low