Method for synchronously preparing iodine pentafluoride and silver fluoride

Abstract

The invention provides a method for preparing iodine pentafluoride through photocatalysis, which comprises the following steps: mixing silver iodide, iodine pentafluoride and potassium iodide to obtain a mixed solution; the method comprises the following steps: under the condition of mixed gas of fluorine and protective gas, carrying out photocatalytic reaction under the irradiation of ultraviolet light, and then separating to respectively obtain iodine pentafluoride and silver fluoride. The reaction of the silver iodide and fluorine is accelerated by utilizing the photosensitive characteristic of the silver iodide, and meanwhile, the iodine pentafluoride and the silver fluoride with high additional values are prepared, so that the preparation reaction efficiency of the iodine pentafluoride is improved, and the iodine pentafluoride production process based on the iodide is efficient, economical and feasible. According to the method, the capacity of the reaction system on the silver iodide is improved by utilizing the potassium iodide, the byproduct high-value silver fluoride is produced in the process of producing the iodine pentafluoride, value-added utilization of the raw materials is realized, and the economic benefit is good; the silver iodide reaction speed is increased, silver fluoride can be selectively produced, and the product purity is high; the reaction process is mild and controllable, and the stability is good.

Description

Technical Field

[0001] The invention belongs to the technical field of iodine pentafluoride production and relates to a method for synchronously preparing iodine pentafluoride and silver fluoride. Background Art

[0002] Iodine pentafluoride is an important raw material for the production of perfluoroiodoethane, IF7, NF3, SF4, C4F6 and other organic and inorganic fluorides. It can also be used in semiconductor etching and cleaning, lithium batteries and other fields. Therefore, it is of great significance to develop industrial preparation technology for iodine pentafluoride. In the prior art, the preparation methods of iodine pentafluoride mainly include the following two categories:

[0003] The first type is to react iodine pentafluoride with single substance I2 as raw material and single substance F2, wherein I2 single substance can participate in the reaction in gaseous state, solid state, melt state, or dissolved state, and its production process can be carried out by intermittent or continuous method. For example, Chinese invention patent (CN101528593) proposes that in the method for making iodine pentafluoride by reacting fluorine and iodine, iodine is supplied to the gas phase adjacent to the liquid of iodine pentafluoride containing iodine, and the liquid phase iodine pentafluoride generated is taken out from the reactor continuously or intermittently. Chinese invention patent (CN101920937A) proposes that solid iodine is placed above liquid iodine pentafluoride or iodine pentafluoride solution, fluorine gas is passed into liquid iodine pentafluoride or iodine pentafluoride solution, and the iodine pentafluoride generated by solid iodine and fluorine reaction flows into liquid iodine pentafluoride or iodine pentafluoride solution after dissolving part of iodine. The Chinese invention patent (CN104326443A) proposes a method for continuous production of iodine pentafluoride in a multi-reactor using iodine pentafluoride and molten iodine as raw materials. This method has high reaction efficiency, but the reaction process is difficult to control due to the intense heat release, and the sublimation of iodine blocks the reaction pipeline, resulting in a high production risk.

[0004] The second method is to use iodine-containing compounds to react with fluorine gas to generate iodine pentafluoride, wherein the iodine compound can be organic or inorganic. For example, US Pat. No. 6,239,319 B1 discloses a method for simultaneously preparing C2-C 10 The process of perfluoroalkane and IF5, the method uses perfluoroalkyl iodide to react with F2 in an inert solvent, and then prepares IF5 by distillation, but IF5 has low production capacity and high raw material prices. Chinese invention patent (CN105523522B) discloses a method of dissolving iodine alkali metal or iodine alkaline earth metal salt in iodine pentafluoride solution, and continuously passing fluorine gas to obtain iodine pentafluoride. The raw materials of this method are cheap and easy to obtain, and a large amount of heat release problems in the reaction process of elemental iodine and fluorine gas are avoided, but the reaction time is long (higher than 150h), and the production efficiency is low.

[0005] Therefore, how to provide a suitable iodine pentafluoride production process to solve the above-mentioned problems existing in the prior art has become one of the focuses of widespread attention of many forward-looking researchers in this field. Summary of the invention

[0006] In view of this, the technical problem to be solved by the present invention is to provide a method for the simultaneous preparation of iodine pentafluoride and silver fluoride. The essence of the present invention is to utilize the photosensitivity of silver iodide to accelerate its reaction with fluorine gas, and simultaneously prepare high value-added iodine pentafluoride and silver fluoride, which is an efficient and economically feasible iodine pentafluoride production process based on iodide. Moreover, the preparation method has simple steps, mild conditions, good stability, strong controllability, and is more suitable for large-scale production promotion and application.

[0007] The present invention provides a method for synchronously preparing iodine pentafluoride and silver fluoride, comprising the following steps:

[0008] 1) mixing silver iodide, iodine pentafluoride and potassium iodide to obtain a mixed solution;

[0009] 2) Under the condition of a mixed gas of fluorine and protective gas and irradiation of ultraviolet light, a photocatalytic reaction is carried out, and then iodine pentafluoride and silver fluoride are obtained after separation.

[0010] Preferably, the mass ratio of potassium iodide to iodine pentafluoride is (0.05-0.1):1;

[0011] The mass ratio of the silver iodide to iodine pentafluoride is (0.02-0.06):1.

[0012] Preferably, the mixing temperature is 20 to 40°C;

[0013] The protective gas includes an inert gas.

[0014] Preferably, the volume ratio of fluorine gas in the mixed gas is 10% to 25%;

[0015] The molar ratio of fluorine gas to silver iodide in the mixed gas is (10-30):1;

[0016] The pressure of the mixed gas is 0.5-3 MPa.

[0017] Preferably, the temperature of the photocatalytic reaction is 50-70°C;

[0018] The photocatalytic reaction time is 10 to 30 hours.

[0019] Preferably, the photocatalytic reaction is specifically carried out under stirring conditions;

[0020] The stirring speed is 200-450 rpm.

[0021] Preferably, the wavelength of the ultraviolet light is 250-400 nm.

[0022] Preferably, the photocatalytic reaction further includes a cooling step;

[0023] The temperature after cooling is 10-20°C.

[0024] Preferably, the separation is solid-liquid separation;

[0025] The separated liquid phase is iodine pentafluoride, and the solid phase is silver fluoride.

[0026] Preferably, the separation further includes a step of distilling the liquid phase.

[0027] The present invention provides a method for synchronously preparing iodine pentafluoride and silver fluoride, comprising the following steps: firstly, silver iodide, iodine pentafluoride and potassium iodide are mixed to obtain a mixed solution; then, under the condition of a mixed gas of fluorine and a protective gas and under the irradiation of ultraviolet light, a photocatalytic reaction is carried out, and then after separation, iodine pentafluoride and silver fluoride are obtained respectively. Compared with the prior art, the present invention particularly designs a method for synchronously preparing iodine pentafluoride and silver fluoride by photocatalysis, the essence of which is to utilize the photosensitivity of silver iodide to accelerate its reaction with fluorine gas, and simultaneously prepare high-value-added iodine pentafluoride and silver fluoride, thereby improving the efficiency of the iodine pentafluoride preparation reaction, and is an efficient and economically feasible iodine pentafluoride production process based on iodide.

[0028] The invention utilizes potassium iodide to increase the capacity of the reaction system for silver iodide, produces high-value silver fluoride as a by-product in the process of producing iodine pentafluoride, realizes the value-added utilization of raw materials, and has good economic benefits; and utilizes a photocatalytic method to increase the reaction speed of silver iodide, can selectively produce silver fluoride, and has a high product purity; the invention has a simple process flow, a mild and controllable reaction process, good stability, and is more conducive to industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A schematic diagram of the process flow of the method for simultaneously preparing iodine pentafluoride and silver fluoride provided by the present invention;

[0030] Figure 2 A graph showing changes in the contents of silver iodide and potassium iodide, the reactants, during the reaction process provided by the present invention;

[0031] Figure 3 It is the ultraviolet absorption spectrum of silver iodide and potassium iodide;

[0032] Figure 4 This is a scanning electron microscope-energy spectrum diagram of the silver fluoride reaction product prepared by the present invention. DETAILED DESCRIPTION

[0033] In order to further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples, but it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than limiting the claims of the invention.

[0034] All raw materials of the present invention have no particular limitation on their sources, and can be purchased from the market or prepared according to conventional methods known to those skilled in the art.

[0035] The raw materials used in the present invention have no particular limitation on their purity. The present invention preferably uses analytical purity or conventional purity in the field of iodine pentafluoride preparation.

[0036] The brands and abbreviations of all raw materials of the present invention are conventional brands and abbreviations in the art. Each brand and abbreviation is clear and definite in the field of its related use. Those skilled in the art can purchase them from the market or prepare them by conventional methods according to the brands, abbreviations and corresponding uses.

[0037] The abbreviations of all processes of the present invention are conventional abbreviations in the field, and each abbreviation is clear and unambiguous in the field of its related use. Those skilled in the art can understand its conventional process steps based on the abbreviations.

[0038] The present invention provides a method for synchronously preparing iodine pentafluoride and silver fluoride, comprising the following steps:

[0039] 1) mixing silver iodide, iodine pentafluoride and potassium iodide to obtain a mixed solution;

[0040] 2) Under the condition of a mixed gas of fluorine and protective gas and irradiation of ultraviolet light, a photocatalytic reaction is carried out, and then iodine pentafluoride and silver fluoride are obtained after separation.

[0041] The invention firstly mixes silver iodide, iodine pentafluoride and potassium iodide to obtain a mixed solution.

[0042] In the present invention, the mass ratio of potassium iodide to iodine pentafluoride is preferably (0.05-0.1):1, more preferably (0.06-0.09):1, and more preferably (0.07-0.08):1.

[0043] In the present invention, the mass ratio of silver iodide to iodine pentafluoride is (0.02-0.06):1, more preferably (0.025-0.055):1, more preferably (0.03-0.05):1, and more preferably (0.035-0.045):1.

[0044] In the present invention, the mixing temperature is preferably 20 to 40°C, more preferably 24 to 36°C, and more preferably 28 to 32°C.

[0045] The invention further performs a photocatalytic reaction under the condition of a mixed gas of fluorine and protective gas and under the irradiation of ultraviolet light, and then obtains iodine pentafluoride and silver fluoride respectively after separation.

[0046] In the present invention, the protective gas preferably includes an inert gas.

[0047] In the present invention, the volume ratio of fluorine gas is preferably 10% to 25%, more preferably 13% to 22%, and even more preferably 16% to 19%.

[0048] In the present invention, the molar ratio of fluorine gas to silver iodide in the mixed gas is preferably (10-30):1, more preferably (17-28):1, more preferably (15-25):1, and more preferably (17-23):1.

[0049] In the present invention, the pressure of the mixed gas is preferably 0.5 to 3 MPa, more preferably 1.0 to 2.5 MPa, and more preferably 1.5 to 2.0 MPa.

[0050] In the present invention, the temperature of the photocatalytic reaction is preferably 50-70°C, more preferably 53-68°C, and more preferably 55-65°C.

[0051] In the present invention, the photocatalytic reaction time is preferably 10 to 30 hours, more preferably 14 to 26 hours, and more preferably 18 to 22 hours.

[0052] In the present invention, the photocatalytic reaction is preferably carried out under stirring conditions.

[0053] In the present invention, the stirring speed is preferably 200 to 450 rpm, more preferably 250 to 400 rpm, and more preferably 300 to 450 rpm.

[0054] In the present invention, the wavelength of the ultraviolet light is preferably 250 to 400 nm, more preferably 280 to 370 nm, and more preferably 310 to 340 nm.

[0055] In the present invention, the photocatalytic reaction preferably further includes a cooling step.

[0056] In the present invention, the temperature after cooling is preferably 10 to 20°C, more preferably 12 to 18°C, and more preferably 14 to 16°C.

[0057] In the present invention, the separation is preferably solid-liquid separation;

[0058] In the present invention, the separated liquid phase is preferably iodine pentafluoride, and the solid phase is preferably silver fluoride.

[0059] In the present invention, the separation preferably further includes a step of distilling the liquid phase.

[0060] The present invention is to complete and refine the overall technical solution, better ensure the characteristics and purity of the products iodine pentafluoride and silver fluoride, and further improve the reaction efficiency of the synchronous preparation process of iodine pentafluoride and silver fluoride. The above-mentioned method for synchronously preparing iodine pentafluoride and silver fluoride by photocatalysis may specifically include the following contents:

[0061] The technical solution of the present invention is as follows:

[0062] (1) adding silver iodide to a mixed solution of iodine pentafluoride and potassium iodide, wherein the mass ratio of potassium iodide to iodine pentafluoride in the mixed solution is 0.05-0.1:1, and the mass ratio of silver iodide to iodine pentafluoride is 0.02-0.06:1, and controlling the temperature in the reactor to be 20-40° C.;

[0063] (2) introducing a mixed gas of fluorine and an inert gas into the reaction, wherein the inert gas is one of argon and helium, the volume ratio of fluorine gas is 10-25%, the molar ratio of fluorine gas to silver iodide in the mixed gas is 10-30:1, the reaction pressure is controlled to be 0.5-3MPa, the reaction temperature is 50-70°C, the stirring speed is controlled to be 200-450 rpm, ultraviolet light with a wavelength of 250-400nm is provided to the reaction system, and the preferred parameter is 320-400nm, and the reaction time is controlled to be 10-30h;

[0064] (3) After the reaction is completed, the reaction is cooled to 10-20° C. for solid-liquid separation. The solid is the silver fluoride product. The liquid is distilled to produce the iodine pentafluoride product. The produced solid, potassium iodide, is returned to step (1).

[0065] See also Figure 1 , Figure 1 The present invention provides a simplified process flow diagram of the method for simultaneously preparing iodine pentafluoride and silver fluoride.

[0066] The above content of the present invention provides a method for synchronously preparing iodine pentafluoride and silver fluoride. The method for synchronously preparing iodine pentafluoride and silver fluoride by photocatalysis designed by the present invention is essentially to utilize the photosensitivity of silver iodide to accelerate its reaction with fluorine gas, and simultaneously prepare high value-added iodine pentafluoride and silver fluoride, thereby improving the efficiency of the iodine pentafluoride preparation reaction, and is an efficient and economically feasible iodine pentafluoride production process based on iodide.

[0067] The invention utilizes potassium iodide to increase the capacity of the reaction system for silver iodide, produces high-value silver fluoride as a by-product in the process of producing iodine pentafluoride, realizes the value-added utilization of raw materials, and has good economic benefits; and utilizes a photocatalytic method to increase the reaction speed of silver iodide, can selectively produce silver fluoride, and has a high product purity; the invention has a simple process flow, a mild and controllable reaction process, good stability, and is more conducive to industrial production.

[0068] In order to further illustrate the present invention, a method for simultaneously preparing iodine pentafluoride and silver fluoride provided by the present invention is described in detail below in conjunction with examples. However, it should be understood that these examples are implemented on the premise of the technical solution of the present invention, and detailed implementation methods and specific operating processes are given only to further illustrate the characteristics and advantages of the present invention, rather than to limit the claims of the present invention, and the protection scope of the present invention is not limited to the following examples.

[0069] Example 1

[0070] 1000g of a mixed solution of iodine pentafluoride and potassium iodide was loaded into the reactor, the mass ratio of potassium iodide to iodine pentafluoride was 0.05:1, silver iodide was added, the mass ratio of silver iodide to iodine pentafluoride was controlled to be 0.02:1, and the temperature in the reactor was controlled to be 20°C. Fluorine-argon mixed gas was introduced into the reaction raw materials, the volume ratio of fluorine gas was 10%, the molar ratio of fluorine gas to silver iodide in the mixed gas was 30:1, the reaction pressure was controlled to be 3MPa, the reaction temperature was controlled to be 70°C, the stirring speed was controlled to be 200 rpm, the wavelength of ultraviolet light irradiation was controlled to be 320-400nm, the reaction time was controlled to be 10h, and the changes in the contents of potassium iodide and silver iodide during the reaction were as follows: Figure 2 shown. Figure 2 The present invention provides a graph showing the changes in the contents of silver iodide and potassium iodide, the reactants, during the reaction process.

[0071] See also Figure 3 , Figure 3 This is the ultraviolet absorption spectrum of silver iodide and potassium iodide.

[0072] After the reaction is completed, the mixture is cooled to 10°C and solid-liquid separation is performed. The solid product is silver fluoride. The electron microscopy and energy spectrum analysis of the product are as follows: Figure 4 shown.

[0073] See also Figure 4 , Figure 4 This is a scanning electron microscope-energy spectrum diagram of the silver fluoride reaction product prepared by the present invention.

[0074] The content of silver iodide in the reaction liquid is shown in Table 1. After the liquid is distilled, an iodine pentafluoride product is produced. Table 1 shows the content of silver iodide in the reaction liquid in the embodiment of the present invention.

[0075] Table 1

[0076] Example Reaction time / h Silver iodide content / g / ml 1 10 0.0013 2 20 0.0028 3 30 0.0048

[0077] Example 2

[0078] 1000g of mixed solution of iodine pentafluoride and potassium iodide was loaded into the reactor, the mass ratio of potassium iodide to iodine pentafluoride was 0.08:1, silver iodide was added, the mass ratio of silver iodide to iodine pentafluoride was controlled to be 0.04:1, and the temperature in the reactor was controlled to be 30°C. Fluorine-helium mixed gas was introduced into the reactants, the volume ratio of fluorine gas was 25%, the molar ratio of fluorine gas to silver iodide in the mixed gas was 20:1, the reaction pressure was controlled to be 2MPa, the reaction temperature was controlled to be 60°C, the stirring speed was controlled to be 300 rpm, the wavelength of ultraviolet light irradiation was controlled to be 250-350nm, and the reaction time was controlled to be 20h. After the reaction was completed, it was cooled to 15°C, solid-liquid separation was performed, the solid product was silver fluoride, and the iodine pentafluoride product was produced after liquid distillation. The content of silver iodide after the reaction was completed is shown in Table 1.

[0079] Example 3

[0080] 1000g of mixed solution of iodine pentafluoride and potassium iodide was loaded into the reactor, the mass ratio of potassium iodide to iodine pentafluoride was 0.1:1, silver iodide was added, the mass ratio of silver iodide to iodine pentafluoride was controlled to be 0.06:1, and the temperature in the reactor was controlled to be 40°C; fluorine-argon mixed gas was introduced into the reactants, the volume ratio of fluorine gas was 15%, the molar ratio of fluorine gas to silver iodide in the mixed gas was 10:1, the reaction pressure was controlled to be 0.5MPa, the reaction temperature was controlled to be 50°C, the stirring speed was controlled to be 450 rpm, the wavelength of ultraviolet light irradiation was controlled to be 250-400nm, and the reaction time was controlled to be 30h. After the reaction was completed, it was cooled to 20°C, solid-liquid separation was performed, the solid product was silver fluoride, and the iodine pentafluoride product was produced after liquid distillation. The content of silver iodide after the reaction was completed is shown in Table 1.

[0081] The above is a detailed introduction to a method for the simultaneous preparation of iodine pentafluoride and silver fluoride provided by the present invention. The principles and implementation methods of the present invention are described in detail using specific examples herein. The description of the above embodiments is only used to help understand the method and its core ideas of the present invention, including the best mode, and also enables any technician in the field to practice the present invention, including the manufacture and use of any device or system, and the implementation of any combined method. It should be pointed out that for ordinary technicians in the technical field, without departing from the principles of the present invention, the present invention can also be improved and modified in a number of ways, and these improvements and modifications also fall within the scope of protection of the claims of the present invention. The scope of patent protection of the present invention is defined by the claims and may include other embodiments that can be thought of by those skilled in the art. If these other embodiments have structural elements that are not different from the textual expression of the claims, or if they include equivalent structural elements that are not substantially different from the textual expression of the claims, then these other embodiments should also be included in the scope of the claims.

Claims

1. A method for simultaneously preparing iodine pentafluoride and silver fluoride, characterized in that: The following steps are involved: 1) mixing silver iodide, iodine pentafluoride and potassium iodide to obtain a mixed solution; 2) Under the condition of a mixed gas of fluorine and protective gas and irradiation of ultraviolet light, a photocatalytic reaction is carried out, and then iodine pentafluoride and silver fluoride are obtained after separation.

2. The method according to claim 1, characterized in that The mass ratio of potassium iodide to iodine pentafluoride is (0.05-0.1):1; The mass ratio of the silver iodide to iodine pentafluoride is (0.02-0.06):

1.

3. The method according to claim 1, characterized in that The mixing temperature is 20 to 40°C; The protective gas includes an inert gas.

4. The method according to claim 1, characterized in that: In the mixed gas, the volume ratio of fluorine gas is 10% to 25%; The molar ratio of fluorine gas to silver iodide in the mixed gas is (10-30):1; The pressure of the mixed gas is 0.5-3 MPa.

5. The method according to claim 1, characterized in that The temperature of the photocatalytic reaction is 50-70°C; The photocatalytic reaction time is 10 to 30 hours.

6. The method according to claim 1, characterized in that The photocatalytic reaction is specifically carried out under stirring conditions; The stirring speed is 200-450 rpm.

7. The method according to claim 1, characterized in that The wavelength of the ultraviolet light is 250-400nm.

8. The method according to claim 1, characterized in that The photocatalytic reaction further includes a cooling step; The temperature after cooling is 10-20°C.

9. The method according to claim 1, characterized in that: The separation is specifically solid-liquid separation; The separated liquid phase is iodine pentafluoride, and the solid phase is silver fluoride.

10. The method according to claim 1, characterized in that The separation further includes a step of rectifying the liquid phase.

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