CN111187230A

CN111187230A - Preparation method of 2,4, 6-trimercapto-1, 3,5 triazine trisodium salt (TMT)

Info

Publication number: CN111187230A
Application number: CN202010029418.0A
Authority: CN
Inventors: 周明财; 孟祥富
Original assignee: Chaoyang Tianming Industry Trade Co ltd
Current assignee: Chaoyang Tianming Industry Trade Co ltd
Priority date: 2020-01-13
Filing date: 2020-01-13
Publication date: 2020-05-22

Abstract

The invention relates to a preparation method of 2,4, 6-trimercapto-1, 3,5 triazine trisodium salt (TMT). Dissolving cyanuric chloride in water, and continuously adding a sodium hydrosulfide solution, wherein the mass percentage of the sodium hydrosulfide solution is 30-50%, the molar ratio of cyanuric chloride to sodium hydrosulfide is 1 (2-3), and the reaction temperature is 10-60 ℃; after dropwise adding sodium hydrosulfide, adding a sodium hydroxide solution with the mass concentration of 30-50%, and controlling the reaction temperature at 40-60 ℃; cooling and crystallizing, adding TMT crystal seeds when the TMT solution is nearly saturated, adding sodium chloride crystals in the crystallization process, and centrifugally filtering and drying the TMT crystals to obtain the TMT finished product. The invention has the advantages of mild process conditions, simple process, high conversion rate, high product content and low production cost.

Description

Preparation method of 2,4, 6-trimercapto-1, 3,5 triazine trisodium salt (TMT)

Technical Field

The invention relates to the technical field of chemical production, in particular to a preparation method of 2,4, 6-trimercapto-1, 3,5 triazine trisodium salt (TMT).

Background

Today, the pollution of heavy metals in waste water faced by many industries due to the increasing environmental importance of the country, the treatment of heavy metals in waste water is more critical, such as: ag⁺、Pb²⁺、Hg⁺The conventional method is not enough to completely remove the heavy metals, so that a treatment mode which is simple in process, flexible in operation and free of secondary environmental pollution needs to be developed, and the 2,4, 6-trimercapto-1, 3,5 triazine trisodium salt has strong complexing capability on the heavy metals and wide adaptability, so that the development and research of the 2,4, 6-trimercapto-1, 3,5 triazine trisodium salt are of great significance.

Few documents are available about the production process of 2,4, 6-trimercapto-1, 3,5 triazine trisodium salt (TMT).

Relevant publications are: patent application 200910141853.6 relates to the preparation of trisodium salt of 2,4, 6-trimercapto-1, 3,5 triazine- "Process for preparing trisodium salt of 2,4, 6-trimercapto-s-triazine", with cyanuric chloride as the starting materialThe raw material is firstly converted into the monosodium salt (TMT-Na) of 2,4,6 trimercapto-s-triazine₁) And disodium salt of 2,4, 6-trimercapto-s-triazine (TMT-Na)₂) The pH was then adjusted to give a 15% solution of the trisodium salt of 2,4,6 trimercapto-s-triazine.

The 2,4, 6-trimercapto-1, 3,5 triazine trisodium salt (TMT) produced by the prior art has low purity and low yield.

Disclosure of Invention

The invention aims to solve the problems and provides a preparation method of 2,4, 6-trimercapto-1, 3,5 triazine trisodium salt (TMT).

In order to solve the problems, the technical scheme adopted by the invention is as follows:

the preparation method of the 2,4, 6-trimercapto-1, 3,5 triazine trisodium salt (TMT) is characterized in that cyanuric chloride is dissolved in water, a sodium hydrosulfide solution is continuously added, the mass percentage of the sodium hydrosulfide solution is 30-50%, the molar ratio of the cyanuric chloride to the sodium hydrosulfide is 1 (2-3), and the reaction temperature is 10-60 ℃; after dropwise adding sodium hydrosulfide, adding a sodium hydroxide solution with the mass concentration of 30-50%, and controlling the reaction temperature at 40-60 ℃; and cooling and crystallizing, controlling the crystallization temperature to be 5-20 ℃ finally, adding 1-5% of TMT crystal seeds when the TMT solution is nearly saturated, adding 1-3% of sodium chloride crystals in the crystallization process, and centrifugally filtering and drying the TMT crystals to obtain the TMT finished product.

Furthermore, the TMT crystal seed is TMT powder, the mass percentage of the TMT crystal seed is not less than 99.0 percent, and the size of the powder is less than 1000 meshes.

Further, the mass percentage of the sodium chloride crystal is not less than 98.0%, and the powder size is less than 1000 meshes.

Compared with the prior art, the invention has the beneficial characteristics that:

the invention overcomes the problems of cyanuric chloride hydrolysis and low TMT yield in the prior art, and adopts the same ion effect in the yield link to improve the TMT yield and the quality thereof in order to meet the requirement of industrial production, and simultaneously, the TMT crystal seed is added to reduce the supersaturation degree, complete crystallization and improve the purity.

The invention has the advantages of mild process conditions, simple process, high conversion rate, high product content and low production cost.

Detailed Description

The following detailed description of the preferred embodiments of the present invention is provided to enable those skilled in the art to more readily understand the advantages and features of the present invention and to clearly and unequivocally define the scope of the present invention.

Example 1

Adding 300 g of cyanuric chloride and 900 ml of water into a conical flask, stirring for dissolving, dropwise adding 860g of sodium hydrosulfide solution within 5 hours, controlling the mass percentage content of the sodium hydrosulfide solution to be 30%, controlling the reaction temperature to be 45 ℃, adding 185 g of caustic soda flakes within 30 minutes after the dropwise adding is completed, controlling the reaction temperature to be 60 ℃, removing the mixture from a crystallization kettle after heat filtration, cooling and crystallizing, controlling the crystallization temperature to be 10 ℃, adding 30g of TMT crystal seeds when the mixture is saturated, controlling the addition amount of the TMT crystal seeds to be 30g, controlling the purity of the added TMT crystal seeds to be 99.5%, controlling the size of the TMT crystal seeds to be 1000 meshes, then adding 30g of sodium chloride crystals, controlling the purity of the sodium chloride crystals to be 98.0%, controlling the size to be 1000 meshes, and obtaining 347g of TMT by centrifugal filtration and drying, wherein.

Example 2

Adding 300 g of cyanuric chloride and 600 ml of water into a conical flask, stirring for dissolving, dropwise adding 690 g of sodium hydrosulfide solution with the mass percentage content of 40% within 3 hours, controlling the reaction temperature to be 45 ℃, then adding 580 g of 32% ionic membrane caustic soda within 60 minutes, controlling the reaction temperature to be 40 ℃, performing heat filtration, then removing a crystallization kettle for cooling and crystallizing, controlling the crystallization temperature to be 5 ℃, adding TMT crystal seeds when the crystallization temperature is close to saturation, wherein the adding amount of the TMT crystal seeds is 10g, the purity of the added TMT crystal seeds is 99.5%, the size of the TMT crystal seeds is 1340 meshes, adding 15g of sodium chloride crystals, the purity of the sodium chloride crystals is 99.0%, the size of the sodium chloride crystals is 1000 meshes, and obtaining 353g of TMT by centrifugal filtration and drying, wherein the yield is 89.3% and the content is 97.5%.

Example 3

Adding 300 g of cyanuric chloride and 800 ml of deionized water into a conical flask, stirring for dissolving, adding 185 g of caustic soda flakes into the conical flask, dropwise adding 690 g of 60% sodium hydrosulfide solution within 3 hours, controlling the reaction temperature to be 50 ℃, performing heat filtration, then adding into a crystallization kettle, cooling, crystallizing, controlling the crystallization temperature to be 20 ℃, adding 50g of TMT crystal seeds when the crystallization temperature is close to saturation, wherein the purity of the added TMT crystal seeds is 99.0%, the size of the added TMT crystal seeds is 1000 meshes, adding 10g of sodium chloride crystals, the purity of the sodium chloride crystals is 99.0%, the size of the sodium chloride crystals is 1000 meshes, performing centrifugal filtration and drying to obtain 338g of TMT, and the yield is 85.5%, and the content is 98.3%.

Example 4

Adding 300 g of cyanuric chloride and 600 ml of water into a conical flask, uniformly stirring, dropwise adding 860g of 32% sodium hydrosulfide solution within 4 hours, controlling the reaction temperature to be 10 ℃, adding 580 g of caustic soda within 90 minutes after the dropwise addition is finished, controlling the reaction temperature to be 60 ℃, removing the mixture from a crystallization kettle after heat filtration, cooling and crystallizing, controlling the crystallization temperature to be less than 10 ℃, adding TMT crystal seeds when the mixture is close to saturation, wherein the addition amount of the TMT crystal seeds is 2g, the purity of the added TMT crystal seeds is 99.0%, the size of the TMT crystal seeds is 1000 meshes, adding 10g of sodium chloride crystals, the purity of the sodium chloride crystals is 99.0%, the size of the sodium chloride crystals is 1000 meshes, and obtaining 358g of TMT by centrifugal filtration and drying, wherein the yield is 90.6% and the content is 98.1.

The foregoing shows and describes the general principles, essential features, and advantages of the invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, that the preferred embodiments of the present invention are described above and the present invention is not limited to the preferred embodiments, and that various changes and modifications may be made without departing from the spirit and scope of the present invention and these changes and modifications are within the scope of the invention as claimed.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims

1. The preparation method of the 2,4, 6-trimercapto-1, 3,5 triazine trisodium salt (TMT) is characterized in that cyanuric chloride is dissolved in water, a sodium hydrosulfide solution is continuously added, the mass percentage of the sodium hydrosulfide solution is 30-50%, the molar ratio of the cyanuric chloride to the sodium hydrosulfide is 1 (2-3), and the reaction temperature is 10-60 ℃; after dropwise adding sodium hydrosulfide, adding a sodium hydroxide solution with the mass concentration of 30-50%, and controlling the reaction temperature at 40-60 ℃; and cooling and crystallizing, controlling the crystallization temperature to be 5-20 ℃ finally, adding 1-5% of TMT crystal seeds when the TMT solution is nearly saturated, adding 1-3% of sodium chloride crystals in the crystallization process, and centrifugally filtering and drying the TMT crystals to obtain the TMT finished product.

2. The method for preparing 2,4, 6-trimercapto-1, 3,5 triazine trisodium salt (TMT) according to claim 1, wherein the TMT seed crystal is TMT powder with mass percentage of not less than 99.0% and powder size of less than 1000 meshes.

3. The preparation method of 2,4, 6-trimercapto-1, 3,5 triazine trisodium salt (TMT) as claimed in claim 1, wherein the mass percentage of sodium chloride crystal is not less than 98.0%, and the powder size is less than 1000 meshes.