Preparation method of high-purity ethylene diamine tetraacetic acid disodium magnesium salt

Abstract

The invention belongs to the technical field of preparation of organic compounds, and relates to a preparation method of high-purity disodium magnesium ethylenediaminetetraacetate, which is characterized in that magnesium chloride is automatically produced into high-purity low-impurity-content basic magnesium carbonate to ensure the high purity and low impurity content of the disodium magnesium ethylenediaminetetraacetate; implementation means include but not limited to magnesium chloride raw material purification, other raw material purification and other means, magnesium chloride is very convenient to obtain, operation is easy and convenient, and the production efficiency is effectively improved.

Description

Technical Field

[0001] The invention belongs to the technical field of organic compound preparation, in particular to a method for preparing high-purity disodium magnesium salt of ethylenediaminetetraacetic acid. Background Art

[0002] Disodium magnesium ethylenediaminetetraacetate is an important compound with broad application prospects. In the complexation of metal ions, disodium magnesium ethylenediaminetetraacetate can form complexes with a variety of metal ions. This complex has strong stability and selectivity and can be used for the separation and extraction of metal ions. In drug formulations, disodium magnesium ethylenediaminetetraacetate tetrahydrate can be used as a stabilizer and complexing agent for formulations. Due to its strong affinity for metal ions, it can effectively reduce the adverse effects of metal ions on drugs and improve the stability and efficacy of drugs. In catalyst preparation, disodium magnesium ethylenediaminetetraacetate tetrahydrate can be used as an important ligand. Through coordination with metal ions, a catalyst with a specific structure and activity can be formed. This catalyst can be used in various organic synthesis reactions and catalytic conversion processes, and has the advantages of high efficiency, selectivity and environmental friendliness.

[0003] In summary, EDTA magnesium salt is a compound with broad application prospects. It has important application value in the fields of metal ion complexation, drug formulation and catalyst preparation. With the continuous development of the chemical field, researchers' in-depth research on this compound and the prospect of its application will further promote the application of this compound in various fields. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a method for preparing high-purity disodium magnesium salt of ethylenediaminetetraacetic acid, which has a short processing time and a high purity of the obtained product.

[0005] The present invention solves the technical problem by adopting the following technical solutions:

[0006] A method for preparing high-purity ethylenediaminetetraacetic acid disodium magnesium salt comprises the following steps:

[0007] S1. Add magnesium chloride, purified water and magnesium oxide to a batching kettle respectively, stir, and heat until all the raw materials are dissolved, then stand until the solution is completely clarified, filter, and obtain solution 1;

[0008] S2, dissolving anhydrous sodium carbonate in pure water, and adding it, solution 1, and sodium hydroxide solution into a reaction kettle respectively, stirring, heating and dissolving until boiling, then standing until the solution is completely clarified, filtering, and obtaining solution 2;

[0009] S3, slowly add solution 2 into another reactor, keep the temperature at 40-80°C, until no more precipitation is produced in the reactor, filter, dry, and obtain purified basic magnesium carbonate;

[0010] S4, respectively adding disodium ethylenediaminetetraacetate and purified water to a reaction kettle, stirring, heating until completely dissolved, then adding 40% sodium hydroxide solution and purified basic magnesium carbonate, then standing until the solution is completely clarified, filtering, and obtaining solution 3;

[0011] S5. Place solution 3 in a concentration kettle for heating and concentration until the liquid is concentrated to one third of the raw material, then cool to room temperature and precipitate crystals, filter, and dry to obtain high-purity disodium magnesium salt of ethylenediaminetetraacetic acid.

[0012] Furthermore, in step S4, the pH needs to be controlled to be 8.2-8.5.

[0013] Moreover, the drying is vacuum drying, and the drying temperature is 70-80°C.

[0014] Moreover, the magnesium chloride is of industrial grade, and the magnesium oxide, sodium hydroxide, disodium ethylenediaminetetraacetate and anhydrous sodium carbonate are of reagent grade.

[0015] The advantages and positive effects of the present invention are:

[0016] 1. The present invention abandons the use of magnesium chloride as the main raw material, and instead uses magnesium chloride to purify basic magnesium carbonate, thereby avoiding the introduction of chloride ions by the raw material magnesium chloride during the reaction process of producing disodium magnesium ethylenediaminetetraacetic acid; at the same time, it avoids the addition of sulfuric acid and hydrosulfuric acid in the process of producing magnesium chloride from magnesite, in which impurities such as sulfide and sulfate are bound to be introduced into the product magnesium chloride, which, like chloride ions, inevitably interfere with chelation selectivity, especially sulfide, sulfate and chloride ions, which will jointly interfere with the application of disodium magnesium ethylenediaminetetraacetic acid in the field of high purity.

[0017] 2. The present invention ensures that the product, magnesium disodium ethylenediaminetetraacetic acid magnesium salt, has high purity and low impurities by producing magnesium chloride as basic magnesium carbonate with high purity and low impurity content. The means for achieving this include but are not limited to purification of magnesium chloride raw materials, purification of other raw materials, etc., and magnesium chloride is very convenient to obtain and easy to operate, thereby effectively improving production efficiency.

[0018] 3. Industrial magnesite is often rich in a series of metal ions such as metallic iron ions, which may cause the metal impurity ions including but not limited to iron ions in the magnesium chloride used as the raw material to exceed the standard, thereby affecting the content of metal impurity ions in disodium magnesium ethylenediaminetetraacetate, thereby reducing its metal selectivity in the metal ion chelation reaction in the application. The present invention effectively improves the purity of the product through simple steps, so that the purity of disodium magnesium ethylenediaminetetraacetate reaches more than 99.5%.

[0019] 4. The present invention provides a method that does not require expensive special equipment during production, and can meet the requirements of high purity of magnesium disodium ethylenediaminetetraacetate, particularly a content of more than 99.5%, and extremely low contents of chloride ions, sulfides, sulfates and metallic iron ions; thereby improving the application of the product in high-precision fields, especially in the fields of chemical reagents and medicine.

[0020] 5. The steps described in the present invention are simple, easy to operate, easy to realize industrial production, and the production and processing time is short, which greatly improves production efficiency and shortens working hours.

[0021] 6. The present invention further reasonably optimizes all raw material ratios and other reaction conditions. DETAILED DESCRIPTION

[0022] The present invention is further described in detail below through specific examples. The following examples are only illustrative and not restrictive, and the protection scope of the present invention cannot be limited thereto.

[0023] Example 1

[0024] A method for preparing high-purity ethylenediaminetetraacetic acid disodium magnesium salt comprises the following steps:

[0025] S1. Into a 3-ton batching kettle equipped with a heating device, electric stirring, a thermometer, and a titration feeder, 600 kg of industrial-grade magnesium chloride and 2 tons of pure water as raw materials are respectively added, and then 3.8 kg of reagent-grade magnesium oxide is added, and the electric stirring is turned on and heated to 80° C. to dissolve the magnesium chloride and magnesium oxide completely, and then the heating is stopped and the electric stirring is turned off, and the solution is allowed to stand until it is completely clarified, and mechanical impurities and precipitates containing iron ions are removed by filtration to obtain a solution 1;

[0026] S2, adding the filtered solution 1 to a 5-ton reactor equipped with a heating device, an electric stirrer, a thermometer, and a titration feeder, and turning on the electric stirrer of the reactor; dissolving 300 kg of anhydrous sodium carbonate in 1.8 tons of pure water in another 3-ton batching kettle equipped with a heating device, an electric stirrer, a thermometer, and a titration feeder, and then adding 0.21 kg of 40% sodium hydroxide solution, turning on the electric stirrer to heat and dissolve until boiling, then stopping the heating and turning off the electric stirrer, standing the solution until it is completely clarified, filtering, and obtaining a solution 2;

[0027] S3, slowly add solution 2 into a 5-ton reactor, keep the temperature at 60°C, until no more precipitation is produced in the reactor, filter the precipitate, and vacuum dry at 70°C to obtain purified basic magnesium carbonate;

[0028] S4, add 670 kg of disodium ethylenediaminetetraacetate and 3 tons of pure water to a 5-ton reactor equipped with a heating device, electric stirring, thermometer, and titration feeder, turn on the electric stirring and heat until they are completely dissolved, then add 0.2 kg of 40% sodium hydroxide solution, and then add 700 kg of newly reacted purified basic magnesium carbonate, control the pH value accurately to 8.2-8.5, and use this as the control point; then stop heating and turn off the electric stirring, let the solution stand until it is completely clarified, pass through a filter column containing activated carbon filler, and after obtaining a clarified solution, slowly add it to a 5-ton concentration kettle to obtain solution 3;

[0029] S5. Heat the 5-ton concentration kettle, keep the electric stirring on and the solution in the concentration kettle boiling, heat and concentrate the liquid to about 1 / 3 of the raw material; stop heating, naturally cool under stirring until the concentration kettle returns to room temperature and crystals precipitate, turn off the electric stirring, filter the crystal precipitate, and vacuum dry at 70°C to obtain high-purity disodium magnesium ethylenediaminetetraacetic acid.

[0030] Example 2

[0031] A method for preparing high-purity ethylenediaminetetraacetic acid disodium magnesium salt comprises the following steps:

[0032] S1. Into a 3-ton batching kettle equipped with a heating device, electric stirring, a thermometer, and a titration feeder, 600 kg of industrial-grade magnesium chloride and 2 tons of pure water as raw materials are respectively added, and then 4.0 kg of reagent-grade magnesium oxide is added, and the electric stirring is turned on and heated to 80° C. to dissolve the magnesium chloride and magnesium oxide completely, and then the heating is stopped and the electric stirring is turned off, and the solution is allowed to stand until it is completely clarified, and mechanical impurities and precipitates containing iron ions are removed by filtration to obtain a solution 1;

[0033] S2, adding the filtered solution 1 to a 5-ton reactor equipped with a heating device, an electric stirrer, a thermometer, and a titration feeder, and turning on the electric stirrer of the reactor; dissolving 300 kg of anhydrous sodium carbonate in 1.8 tons of pure water in another 3-ton batching kettle equipped with a heating device, an electric stirrer, a thermometer, and a titration feeder, and then adding 0.22 kg of 40% sodium hydroxide solution, turning on the electric stirrer to heat and dissolve until boiling, then stopping the heating and turning off the electric stirrer, standing the solution until it is completely clarified, filtering, and obtaining a solution 2;

[0034] S3, slowly add solution 2 into a 5-ton reactor, keep the temperature at 60°C, until no more precipitation is produced in the reactor, filter the precipitate, and vacuum dry at 70°C to obtain purified basic magnesium carbonate;

[0035] S4, add 670 kg of disodium ethylenediaminetetraacetate and 3 tons of pure water to a 5-ton reactor equipped with a heating device, electric stirring, thermometer, and titration feeder, turn on the electric stirring and heat until they are completely dissolved, then add 0.2 kg of 40% sodium hydroxide solution, and then add 710 kg of newly reacted purified basic magnesium carbonate, control the pH value accurately to 8.2-8.5, and use this as the control point; then stop heating and turn off the electric stirring, let the solution stand until it is completely clarified, pass through a filter column containing activated carbon filler, obtain a clarified solution, and slowly add it to a 5-ton concentration kettle to obtain solution 3;

[0036] S5, heating the 5-ton concentration kettle, keeping the electric stirring on and the solution in the concentration kettle boiling, heating and concentrating the liquid to about 1 / 3 of the raw material; stopping heating, stirring and cooling naturally until the concentration kettle returns to room temperature and crystals are precipitated, turning off the electric stirring, filtering the crystal precipitate, and vacuum drying at 80°C; obtaining high-purity disodium magnesium ethylenediaminetetraacetic acid.

[0037] Example 3

[0038] A method for preparing high-purity ethylenediaminetetraacetic acid disodium magnesium salt comprises the following steps:

[0039] S1. Into a 3-ton batching kettle equipped with a heating device, electric stirring, a thermometer, and a titration feeder, 600 kg of industrial-grade magnesium chloride and 2 tons of pure water as raw materials are respectively added, and then 4.3 kg of reagent-grade magnesium oxide is added, and the electric stirring is turned on and heated to 80° C. to completely dissolve the magnesium chloride and magnesium oxide, and then the heating is stopped and the electric stirring is turned off, and the solution is allowed to stand until it is completely clarified, and mechanical impurities and precipitates containing iron ions are removed by filtration to obtain a solution 1;

[0040] S2, adding the filtered solution 1 to a 5-ton reactor equipped with a heating device, an electric stirrer, a thermometer, and a titration feeder, and turning on the electric stirrer of the reactor; dissolving 300 kg of anhydrous sodium carbonate in 1.8 tons of pure water in another 3-ton batching kettle equipped with a heating device, an electric stirrer, a thermometer, and a titration feeder, and then adding 0.23 kg of 40% sodium hydroxide solution, turning on the electric stirrer to heat and dissolve until boiling, then stopping the heating and turning off the electric stirrer, standing the solution until it is completely clarified, filtering, and obtaining a solution 2;

[0041] S3, slowly add solution 2 into a 5-ton reactor, keep the temperature at 60°C, until no more precipitation is produced in the reactor, filter the precipitate, and vacuum dry at 70°C to obtain purified basic magnesium carbonate;

[0042] S4, add 670 kg of disodium ethylenediaminetetraacetate and 3 tons of pure water to a 5-ton reactor equipped with a heating device, electric stirring, thermometer, and titration feeder, turn on the electric stirring and heat until they are completely dissolved, then add 0.2 kg of 40% sodium hydroxide solution, and then add 715 kg of newly reacted purified basic magnesium carbonate, control the pH value accurately to 8.2--8.5, and use this as the control point; then stop heating and turn off the electric stirring, let the solution stand until it is completely clarified, pass through a filter column containing activated carbon filler, and after obtaining a clarified solution, slowly add it to a 5-ton concentration kettle to obtain solution 3;

[0043] S5, heating the 5-ton concentration kettle, keeping the electric stirring on and the solution in the concentration kettle boiling, heating and concentrating the liquid to about 1 / 3 of the raw material; stopping heating, stirring and cooling naturally until the concentration kettle returns to room temperature and crystals are precipitated, turning off the electric stirring, filtering the crystal precipitate, and vacuum drying at 80°C; obtaining high-purity disodium magnesium ethylenediaminetetraacetic acid.

[0044] Although the embodiments of the present invention are disclosed for illustrative purposes, those skilled in the art will appreciate that various substitutions, changes and modifications are possible without departing from the spirit and scope of the present invention and the appended claims. Therefore, the scope of the present invention is not limited to the contents disclosed in the embodiments.

Claims

1. A method for preparing high-purity ethylenediaminetetraacetic acid disodium magnesium salt, characterized in that: The steps include: S1. Add magnesium chloride, purified water and magnesium oxide to a batching kettle respectively, stir, and heat until all the raw materials are dissolved, then stand until the solution is completely clarified, filter, and obtain solution 1; S2, dissolving anhydrous sodium carbonate in pure water, and adding it, solution 1, and sodium hydroxide solution into a reaction kettle respectively, stirring, heating and dissolving until boiling, then standing until the solution is completely clarified, filtering, and obtaining solution 2; S3, slowly add solution 2 into another reactor, keep the temperature at 40-80°C, until no more precipitation is produced in the reactor, filter, dry, and obtain purified basic magnesium carbonate; S4, respectively adding disodium ethylenediaminetetraacetate and purified water to a reaction kettle, stirring, heating until completely dissolved, then adding 40% sodium hydroxide solution and purified basic magnesium carbonate, then standing until the solution is completely clarified, filtering, and obtaining solution 3; S5. Place solution 3 in a concentration kettle for heating and concentration until the liquid is concentrated to one third of the raw material, then cool to room temperature and precipitate crystals, filter, and dry to obtain high-purity disodium magnesium salt of ethylenediaminetetraacetic acid.

2. The method for preparing high-purity ethylenediaminetetraacetic acid disodium magnesium salt according to claim 1, characterized in that: In step S4, the pH needs to be controlled at 8.2-8.

5.

3. The method for preparing high-purity ethylenediaminetetraacetic acid disodium magnesium salt according to claim 1, characterized in that: The drying is vacuum drying at a temperature of 70-80°C.

4. The method for preparing high-purity ethylenediaminetetraacetic acid disodium magnesium salt according to claim 1, characterized in that: The magnesium chloride is of industrial grade, and the magnesium oxide, sodium hydroxide, disodium ethylenediaminetetraacetate, and anhydrous sodium carbonate are of reagent grade.