A method for preparing potassium iodide and ammonium iodide based on micro-chemical reaction technology

Abstract

The application discloses a preparation method of potassium iodide and ammonium iodide based on micro-chemical reaction technology, and comprises the following steps: (1) mixing hydrazine hydrate and potassium hydroxide according to a molar ratio of 4:1-1:8 to prepare 0.5 mol·L ‑1 Solution as the dispersed phase of the micro-reactor; (2) dispersing elemental iodine into water according to a molar ratio of 1:60-1:500 to prepare a suspension as the continuous phase; (3) pumping the solution prepared in the step 1 into the dispersed phase inlet at the same flow rate, pumping the iodine suspension prepared in the step 2 into the continuous phase, and carrying out reaction at normal temperature; and potassium iodide and ammonium iodide products can be obtained after concentration, crystallization and separation. The application realizes continuous, safe and efficient production of potassium iodide and ammonium iodide by using micro-chemical continuous reaction technology, and by skillfully selecting hydrazine hydrate as a reducing agent, potassium hydroxide as a pH regulator of a reaction system, and optimizing the raw material ratio and the feeding flow rate of the three.

Description

Technical Field

[0001] This invention belongs to the field of chemical technology, specifically relating to a method for preparing potassium iodide and ammonium iodide based on microchemical continuous synthesis technology. Background Technology

[0002] Iodine is a nonmetallic element in various forms. It can form compounds with all elements except sulfur, selenium, and inert gases. It exhibits strong biocompatibility, high reactivity, and is easily oxidized and reduced, volatile, and adsorbed. Elemental iodine can be used as a raw material for synthesizing iodides such as potassium iodide, hydroiodic acid, ammonium iodide, potassium iodate, iodomethane, and trifluoroiodomethane. These iodides have wide applications in chemical raw material preparation, pharmaceutical production, catalytic organic synthesis, material dopants, food and feed additives, fire extinguishing agents, lasers, solar cells, and photography.

[0003] The preparation of iodide products such as potassium iodide and ammonium iodide from elemental iodine usually involves adding a reducing agent, an oxidizing agent, and a pH adjuster in a batch reactor in a certain proportion to complete the reaction. However, the violent redox reaction in the process can easily generate a large amount of gas and heat, posing serious safety hazards to the production. At the same time, batch operation also has the problem of generally low production efficiency. Summary of the Invention

[0004] The purpose of this invention is to overcome the above-mentioned shortcomings and provide a continuous, safe, efficient method for simultaneously synthesizing potassium iodide and ammonium iodide.

[0005] The objective of this invention is achieved through the following technical solution.

[0006] The present invention provides a method for preparing potassium iodide and ammonium iodide based on microchemical continuous reaction technology, comprising the following steps:

[0007] (1) 0.5 mol·L⁻¹ hydrazine hydrate was prepared by mixing hydrazine hydrate and potassium hydroxide in a molar ratio of 4:1-1:8. -1 The solution serves as the dispersed phase in the microreactor;

[0008] (2) Elemental iodine is dispersed in water at a molar ratio of 1:60 to 1:500 to obtain a continuous suspension.

[0009] (3) Use a pump to apply two equal flow rates of 20-80 ml·min -1 The solution obtained in step 1 is fed into the dispersed phase inlet, and the iodine suspension obtained in step 2 is fed into the continuous phase. The sieve diameter of the microreactor is 10~100 mm. The reaction is carried out at room temperature. After concentration, crystallization and separation, potassium iodide and ammonium iodide products can be obtained.

[0010] Using the above method, the utilization rate of elemental iodine is higher than 96.2%.

[0011] Furthermore, in step (3), the two identical flow rates are controlled at 20-80 ml·min. -1 .

[0012] Furthermore, the sieve diameter of the microreactor is 10~100 mm.

[0013] Compared with existing technologies, this invention has significant advantages. As can be seen from the above technical solution, by employing microchemical continuous reaction technology to prepare ammonium iodide and potassium iodide, and by cleverly selecting hydrazine hydrate as a reducing agent and potassium hydroxide as a pH adjuster for the reaction system, and optimizing the ratio of the three raw materials and the feed flow rate, continuous, safe, and efficient production of potassium iodide and ammonium iodide is achieved. The utilization rate of elemental iodine in this invention is higher than 96.2%. Implementation

[0014] The present invention will be further described below through specific embodiments. Example 1

[0015] The present invention provides a method for preparing potassium iodide and ammonium iodide based on microchemical continuous reaction technology, comprising the following steps:

[0016] (1) 0.5 mol·L⁻¹ hydrazine hydrate and potassium hydroxide were prepared by mixing them in a molar ratio of 4:1. -1 The solution serves as the dispersed phase in the microreactor;

[0017] (2) The elemental iodine is dispersed in water at a molar ratio of 1:60 to water to obtain a continuous suspension.

[0018] (3) Use a pump to apply two equal flow rates of 20 ml·min -1 The solution obtained in step 1 is fed into the dispersed phase inlet, and the iodine suspension obtained in step 2 is fed into the continuous phase. The sieve diameter of the microreactor is 10 mm. The reaction is carried out at room temperature. After concentration, crystallization and separation, potassium iodide and ammonium iodide products can be obtained.

[0019] The conversion rate of elemental iodine was found to be 98.9%. Example 2

[0020] The present invention provides a method for preparing potassium iodide and ammonium iodide based on microchemical continuous reaction technology, comprising the following steps:

[0021] (1) 0.5 mol·L⁻¹ hydrazine hydrate and potassium hydroxide were prepared by mixing them in a molar ratio of 4:1. -1 The solution serves as the dispersed phase in the microreactor;

[0022] (2) The suspension is prepared by dispersing elemental iodine in water at a molar ratio of 1:500 to water to obtain a continuous phase.

[0023] (3) Use a pump to apply two equal flow rates of 20 ml·min -1 The solution obtained in step 1 is fed into the dispersed phase inlet, and the iodine suspension obtained in step 2 is fed into the continuous phase. The sieve diameter of the microreactor is 10 mm. The reaction is carried out at room temperature. After concentration, crystallization and separation, potassium iodide and ammonium iodide products can be obtained.

[0024] The conversion rate of elemental iodine was found to be 99.4%. Example 3

[0025] The present invention provides a method for preparing potassium iodide and ammonium iodide based on microchemical continuous reaction technology, comprising the following steps:

[0026] (1) 0.5 mol·L⁻¹ hydrazine hydrate and potassium hydroxide were prepared by mixing them in a molar ratio of 1:8. -1 The solution serves as the dispersed phase in the microreactor;

[0027] (2) The suspension is prepared by dispersing elemental iodine in water at a molar ratio of 1:500 to water to obtain a continuous phase.

[0028] (3) Use a pump to press two pumps at the same flow rate of 80 ml·min -1 The solution obtained in step 1 is fed into the dispersed phase inlet, and the iodine suspension obtained in step 2 is fed into the continuous phase. The sieve diameter of the microreactor is 100 mm. The reaction is carried out at room temperature. After concentration, crystallization and separation, potassium iodide and ammonium iodide products can be obtained.

[0029] The conversion rate of elemental iodine was found to be 97.5%. Example 4

[0030] The present invention provides a method for preparing potassium iodide and ammonium iodide based on microchemical continuous reaction technology, comprising the following steps:

[0031] (1) 0.5 mol·L⁻¹ hydrazine hydrate and potassium hydroxide were prepared by mixing them in a molar ratio of 1:8. -1 The solution serves as the dispersed phase in the microreactor;

[0032] (2) The elemental iodine is dispersed in water at a molar ratio of 1:60 to water to obtain a continuous suspension.

[0033] (3) Use a pump to press two pumps at the same flow rate of 80 ml·min -1 The solution obtained in step 1 is fed into the dispersed phase inlet, and the iodine suspension obtained in step 2 is fed into the continuous phase. The sieve diameter of the microreactor is 100 mm. The reaction is carried out at room temperature. After concentration, crystallization and separation, potassium iodide and ammonium iodide products can be obtained.

[0034] The conversion rate of elemental iodine was found to be 96.2%. Example 5

[0035] The present invention provides a method for preparing potassium iodide and ammonium iodide based on microchemical continuous reaction technology, comprising the following steps:

[0036] (1) 0.5 mol·L⁻¹ hydrazine hydrate and potassium hydroxide were prepared by mixing them in a molar ratio of 2:1. -1 The solution serves as the dispersed phase in the microreactor;

[0037] (2) The elemental iodine is dispersed in water at a molar ratio of 1:60 to water to obtain a continuous suspension.

[0038] (3) Use a pump to apply two equal flow rates of 20 ml·min -1 The solution obtained in step 1 is fed into the dispersed phase inlet, and the iodine suspension obtained in step 2 is fed into the continuous phase. The sieve diameter of the microreactor is 10 mm. The reaction is carried out at room temperature. After concentration, crystallization and separation, potassium iodide and ammonium iodide products can be obtained.

[0039] The conversion rate of elemental iodine was found to be 99.8%. Example 6

[0040] A method for preparing potassium iodide and ammonium iodide based on microchemical continuous reaction technology according to the present invention includes the following steps:

[0041] (1) 0.5 mol·L⁻¹ hydrazine hydrate and potassium hydroxide were prepared by mixing them in a molar ratio of 2:1. -1 The solution serves as the dispersed phase in the microreactor;

[0042] (2) The suspension is prepared by dispersing elemental iodine in water at a molar ratio of 1:120 to water to obtain a continuous phase.

[0043] (3) Use a pump to apply two equal flow rates of 60 ml·min -1 The solution obtained in step 1 is fed into the dispersed phase inlet, and the iodine suspension obtained in step 2 is fed into the continuous phase. The sieve diameter of the microreactor is 50 mm. The reaction is carried out at room temperature. After concentration, crystallization and separation, potassium iodide and ammonium iodide products can be obtained.

[0044] The conversion rate of elemental iodine was found to be 98.9%. Example 7

[0045] The present invention provides a method for preparing potassium iodide and ammonium iodide based on microchemical continuous reaction technology, comprising the following steps:

[0046] (1) 0.5 mol·L⁻¹ hydrazine hydrate and potassium hydroxide were prepared by mixing them in a molar ratio of 1:1. -1 The solution serves as the dispersed phase in the microreactor;

[0047] (2) The suspension is prepared by dispersing elemental iodine in water at a molar ratio of 1:120 to water to obtain a continuous phase.

[0048] (3) Use a pump to apply two equal flow rates of 60 ml·min -1 The solution obtained in step 1 is fed into the dispersed phase inlet, and the iodine suspension obtained in step 2 is fed into the continuous phase. The sieve diameter of the microreactor is 50 mm. The reaction is carried out at room temperature. After concentration, crystallization and separation, potassium iodide and ammonium iodide products can be obtained.

[0049] The conversion rate of elemental iodine was found to be 98.3%.

[0050] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments without departing from the technical essence of the present invention shall still fall within the scope of the present invention.

Claims

1. A method for preparing potassium iodide and ammonium iodide based on micro-chemical continuous synthesis technology, characterized in that, comprising the following steps: (2) dispersing elemental iodine into water to prepare a suspension as a continuous phase according to a molar ratio of elemental iodine to water of 1:60-1:500; (1) 0.5 mol L of hydrazine hydrate was mixed with potassium hydroxide in a molar ratio of 4:1-1:8 to prepare a solution -1 as the dispersed phase of the microreactor; (3) pumping the solution prepared in step 1 into the inlet of the dispersed phase at two same flow rates, pumping the iodine suspension prepared in step 2 into the continuous phase, and performing the reaction at normal temperature in a micro-reactor with a mesh diameter of 10-100 mm, so that potassium iodide and ammonium iodide products can be obtained after concentration and crystallization separation. The utilization rate of elemental iodine is higher than 96.2%.

2. The production method according to claim 1, characterized by, The mesh diameter of the micro-reactor is 10-100 mm.

3. The preparation method according to claim 1, characterized in that, The two identical isoflow controls of step (3) are at 20-80 ml min -1 .

4. The method according to any one of claims 1 to 3, characterized in that, ​