Preparation method of high-purity yellow phosphorus

Abstract

The application discloses a preparation method of high-purity yellow phosphor, which comprises the following steps: (1) adding pure water into a reaction kettle, adding liquefied yellow phosphor under the condition of heat preservation, starting a stirrer in the reaction kettle, and repeatedly rinsing the yellow phosphor to remove floating impurities; (2) introducing the rinsed yellow phosphor into a circulating fluidized bed reactor provided with a catalyst bed after fully mixing the yellow phosphor with an oxidizing agent through a mixer, fully contacting a mixed fluid of the yellow phosphor and the oxidizing agent with catalyst filling materials in the catalyst bed, and performing an oxidation-reduction reaction; (3) after the oxidation-reduction reaction is completed, the yellow phosphor is flowed back to the reaction kettle from the circulating fluidized bed reactor, and the yellow phosphor flowed back to the reaction kettle is pumped into the circulating fluidized bed reactor to circulate the above oxidation-reduction reaction; and (4) after the reaction is completed, the liquefied industrial yellow phosphor in the reaction kettle is left to be stratified, impurities are removed, refined yellow phosphor is separated, and high-purity yellow phosphor is obtained by rinsing with high-purity water.

Description

Technical Field

[0001] This invention relates to a method for purifying yellow phosphorus, and more particularly to a method for producing high-purity yellow phosphorus, belonging to the field of yellow phosphorus preparation technology. Background Technology

[0002] High-purity yellow phosphorus is mainly used in semiconductor manufacturing, lithium battery materials, electronics industry and specialty chemical fields. Its core applications are concentrated in the preparation of semiconductor dopants (such as indium phosphide, gallium phosphide, etc.), for wafer cleaning and etching processes (electronic grade phosphoric acid), and functional layer materials such as photodetectors and solar cells.

[0003] Industrial yellow phosphorus is often produced using the electric furnace process, where coke reduces phosphate rock to elemental phosphorus. Yellow phosphorus molecules have a tetrahedral structure, with phosphorus at each of the four vertices. During this process, other impurities from the ore may also be introduced into the yellow phosphorus. In particular, arsenic, a member of the same group, may also be reduced to elemental arsenic, potentially displacing phosphorus in the tetrahedral structure, making it difficult to separate arsenic impurities from phosphorus.

[0004] Therefore, simple methods such as distillation and rectification are insufficient to separate arsenic from yellow phosphorus. Currently, the main processes for arsenic removal from yellow phosphorus include distillation, alloy vacuum distillation, oxidation, solvent extraction, phosphine decomposition, zone melting, melt crystallization, and adsorption.

[0005] US Patent (US4483746A) discloses a phosphorus purification process. Under a distillation temperature ≤200℃ and a vacuum pressure of approximately 13.33 kPa, yellow phosphorus is distilled. The purified yellow phosphorus contains 1 ppm of arsenic, indicating an unsatisfactory arsenic removal effect. Oxidation method: Sulfuric acid and nitric acid are generally used as oxidants (US5310530A, US6146610A) to reduce impurities in phosphorus. This is currently the most commonly used industrial treatment method. Arsenic in industrial yellow phosphorus mostly exists in elemental form and has a slightly stronger reducing ability than in yellow phosphorus itself. Therefore, concentrated sulfuric acid and nitric acid are used as oxidants to treat yellow phosphorus to achieve arsenic removal. A method for oxidative arsenic removal from yellow phosphorus (CN111533097A) uses nitric acid as an oxidant and potassium iodide solution as a catalyst to treat yellow phosphorus, reducing the arsenic content to 2 ppm, achieving an arsenic removal rate of 99.6% and a phosphorus recovery rate of 94%. However, this type of oxidation method rarely achieves arsenic levels below 1 ppm, and it consumes a large amount of yellow phosphorus, posing operational safety risks and generating difficult-to-treat sulfuric and nitric acid waste. Adsorption method: A patented method for generating high-purity yellow phosphorus (CN101759164A) uses activated carbon and diatomaceous earth adsorption to remove arsenic from yellow phosphorus, achieving a purity of 5N-6N. However, the operation is complex, and the phosphorus adsorbed by activated carbon and diatomaceous earth is difficult to desorb and recover. Other methods, such as solvent extraction, phosphine decomposition, zone melting, and melt crystallization, are only suitable for small-scale trials due to operational limitations, significant safety hazards, and high costs; they are not suitable for large-scale industrial production.

[0006] In summary, the production of high-purity yellow phosphorus has always been a challenging issue. Impurities in yellow phosphorus mainly consist of metallic elements, half-metallic elements (Fe, Ca, Co, Mg, Cr, Cd, Mn, Ni, Cu, Pb, Zn, Al, As, etc.), and organic impurities. Among these, the half-metallic element arsenic and organic compounds are the most difficult to handle. Currently, existing technologies for preparing high-purity yellow phosphorus all have numerous problems, limiting their industrial application. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide a method for preparing high-purity yellow phosphorus. The method is a multi-stage purification coupling method that uses high-efficiency catalysis, circulating fluidized bed reaction and rinsing to produce high-purity yellow phosphorus with organic impurities of less than 1 ppb and metal impurities of less than 10 ppb. This method provides raw materials for the preparation of semiconductor dopants and etchant cleaners (electronic grade phosphoric acid).

[0008] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0009] A method for preparing high-purity yellow phosphorus includes the following steps:

[0010] (1) Add pure water to the reactor, and under heat preservation conditions, add liquefied industrial yellow phosphorus, turn on the stirrer in the reactor, and repeatedly rinse the liquefied industrial yellow phosphorus to remove floating impurities.

[0011] (2) After rinsing, the yellow phosphorus is thoroughly mixed with the oxidant through a mixer and then introduced into a circulating fluidized bed reactor equipped with a catalyst bed. The mixture of yellow phosphorus and oxidant is in full contact with the catalyst packing in the catalyst bed to carry out an oxidation-reduction reaction.

[0012] (3) After the redox reaction is completed, the yellow phosphorus flows back from the circulating fluidized bed reactor into the reactor, and then the yellow phosphorus that flows back into the reactor is pumped into the circulating fluidized bed reactor to circulate the above redox reaction.

[0013] (4) After the reaction is complete, the liquefied industrial yellow phosphorus in the reactor is allowed to stand and separate into layers to remove floating impurities, separate the refined yellow phosphorus, and then rinse with high-purity water to obtain high-purity yellow phosphorus.

[0014] The aforementioned method for preparing high-purity yellow phosphorus is characterized in that: the oxidant is one or two of persulfate, perdisulfate, peracetic acid, chlorate, nitric acid, m-chloroperoxybenzoic acid, Desmond reagent, and diisopropyl peroxycarbonate.

[0015] The catalyst supported in the catalyst packing is a nano-metal-organic framework material, including Mn-MoFs, Ce-MOFs, Fe-MOFs, FeMo-MOFs, ZnP-COF, CuP-COF, and Fe... 0 One or two of -COF102;

[0016] The rinsing agent added during rinsing in step (1) is one or two of the following high-purity aqueous solutions: polymethoxyphosphoric acid, phosphoric acid, polyether polyol, aminodimethylphosphonic acid, and ethylenediaminetetraacetic acid.

[0017] The aforementioned method for preparing high-purity yellow phosphorus is characterized in that: the volume of the oxidant added is 10%-30% of the volume of yellow phosphorus, the volume of the catalyst added is 5%-10% of the volume of yellow phosphorus, and the volume of the washing agent added is 5%-10% of the volume of yellow phosphorus.

[0018] The aforementioned method for preparing high-purity yellow phosphorus is characterized in that: the catalyst is supported on a resin-based spherical activated carbon matrix by polyvinylidene fluoride to form a catalyst filler, wherein the total catalyst loading is 10%-20%, and the outer surface loading of the resin-based spherical activated carbon matrix is ​​2%-5%, and the particle size of the catalyst carbon spheres in the catalyst filler is 0.6-6 mm, and the bulk density is 0.6-0.8 g / mL.

[0019] The aforementioned method for preparing high-purity yellow phosphorus is characterized in that: the mixer includes a pipeline static mixer or a jet pump mixer.

[0020] The aforementioned method for preparing high-purity yellow phosphorus is characterized in that: the circulating fluidized bed reactor includes a bed body, a catalyst bed, a partition plate, a discharge port, and a reactor wall, and has the functions of liquid-solid circulation enhanced mass transfer and continuous circulation regeneration of the catalyst bed.

[0021] The aforementioned method for preparing high-purity yellow phosphorus is characterized in that: the temperature of the reaction vessel is 50-70℃, and the cyclic reaction time is 5-10 hours.

[0022] The aforementioned method for preparing high-purity yellow phosphorus is characterized in that: throughout the entire production process, the yellow phosphorus in the reactor is covered with pure water, and the water level is no less than 10 cm below the surface of the yellow phosphorus liquid.

[0023] The aforementioned method for preparing high-purity yellow phosphorus is characterized in that: in step (2), before adding yellow phosphorus and oxidant into the circulating fluidized bed reactor, pure water is filled inside to remove air.

[0024] The aforementioned method for preparing high-purity yellow phosphorus is characterized by the following preparation process for the catalyst filler: polyvinylidene fluoride is dissolved in N,N-dimethylformamide solvent, a catalyst is added, and the mixture is stirred until uniformly dispersed. Then, a resin-based spherical activated carbon substrate is added, and the catalyst is fully adsorbed by ultrasonic vibration. Finally, the substrate is cured into a film to form the catalyst filler. The resin-based spherical activated carbon substrate has a particle size of 0.6-5 mm, a bulk density of 0.42-0.75 g / mL, an iodide value >800 mg / g, and is pre-treated by soaking in 5% electronic-grade nitric acid and washing with ultrapure water to remove impurities before drying.

[0025] The beneficial effects of this invention are as follows: High-purity yellow phosphorus is prepared through a multi-stage purification coupling method of high-efficiency catalysis-circulating fluidized bed reaction-complexation rinsing. By combining a circulating fluidized bed reactor, the catalytic reaction and the circulating process are separated and coupled. During catalytic oxidation, the contact area between the aqueous phase and solid catalyst of the yellow phosphorus and oxidant mixture is significantly increased, thereby improving the redox reaction rate and the efficiency of arsenic and metal removal, reducing the reaction temperature, reducing the loss of oxidant and catalyst, and lowering production costs. This solves the problem of preparing high-purity yellow phosphorus at lower temperatures and atmospheric pressure, improves purification efficiency, and the entire process equipment is simple, requires low investment, and yields quick results. It operates at atmospheric pressure and low temperature, is safe, and is conducive to industrialization. The yellow phosphorus recovery rate is high, reaching over 98%, and the product purity is high, reaching 6N-7N grade. This is of great significance for the subsequent preparation of electronic-grade phosphoric acid and is a highly efficient, energy-saving, low-cost, safe, and environmentally friendly method for purifying high-purity yellow phosphorus. Attached Figure Description

[0026] Figure 1 This is a process flow diagram of a method for preparing high-purity yellow phosphorus according to the present invention. Detailed Implementation

[0027] To make the technical solution of the present invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. Of course, the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0028] All embodiments of the present invention include: a 5-liter jacketed hot water heating reactor, wherein the reactor is equipped with an adjustable speed stirring device and a reaction liquid temperature measuring device; a circulating fluidized bed reactor with an effective volume of 1250 ml, wherein the catalyst bed volume is 500 ml (the upper and lower partitions are distributed with a mesh size of φ0.5 mm), and is equipped with a high-efficiency dispersion mixer. Example 1

[0029] like Figure 1 As shown, using high-quality yellow phosphorus (As content 78 ppm, total conventional metal content 7 ppm) as raw material, Fe... 0High-purity yellow phosphorus was prepared using a multi-stage purification coupling method involving high-efficiency catalysis, circulating fluidized bed reaction, and complexation rinsing, with COF102 as the catalyst and nitric acid water as the oxidant. Specifically:

[0030] First, add 1250mL of pure water to the reactor and heat it to 60℃. Pump in 2 liters (about 3.5kg) of liquid yellow phosphorus at 60℃, turn on the stirring device, add 150mL of rinsing agent polymethic acid and 50mL of ethylenediaminetetraacetic acid, stir and rinse the yellow phosphorus to remove incompatible impurities such as ash and coke floating on the surface of the yellow phosphorus. Rinse until there are no obvious residues on the surface of the yellow phosphorus. Rinse is complete.

[0031] Next, the circulating fluidized bed reactor is filled with pure water to purge the air. Then, the valve is switched to input the pre-purified yellow phosphorus from the reactor into the mixer. Simultaneously, the valve of the oxidant storage tank is opened to input the oxidant solution into the mixer and mix it thoroughly with the yellow phosphorus. The mixed solution is then mixed with the catalyst packing material in the catalyst-filled bed. Under the induction of the catalyst, the oxidant undergoes a redox reaction with arsenic and other elements. The oxidized arsenic enters the liquid phase in the form of arsenic acid and arsenous acid, which can be separated from the yellow phosphorus. At the same time, the resin-based spherical activated carbon substrate in the catalyst packing material also has an adsorption and removal effect on metal ions. The redox-reduced yellow phosphorus is then returned to the reactor to repeat the above redox process. In this embodiment, the oxidant is 20% nitric acid, with an addition amount of 0.6L, and the supported nano-catalyst Fe is used. 0 The catalyst was 200 mL (approximately 125 g) of COF102, and the total reaction time was 6 hours.

[0032] Finally, a rinsing agent is added to the reactor to rinse the yellow phosphorus. After 1 hour, most of the water layer in the reactor is removed, but the remaining water layer should be at least 10 cm below the surface of the yellow phosphorus solution to ensure safety. Then, pure water is added for multiple rinses until the pH of the water layer is close to neutral (pH=6). A water sample is taken for testing. When the total content of conventional metal ions (K, Na, Ca, Mg, Fe, Zn, Cr, Ni, Sb) is less than 50 ppb, the rinsing is complete.

[0033] Tests showed that the total metal impurities in the yellow phosphorus were below 30 ppb, arsenic was 60 ppb, the yellow phosphorus yield was 94.2%, and carbon disulfide (CS2) insoluble matter was less than 0.5 ppm. The product was pumped into a high-purity phosphorus storage tank for later use.

[0034] In this embodiment, the mixer is either a pipeline static mixer or a jet pump mixer. The oxidant solution is injected into the yellow phosphorus delivery pipeline at the front end of the mixer via a high-precision intelligent peristaltic pump and a PTFE hose (or, if a jet pump is used, it can be added from the suction port). After being fully mixed with the yellow phosphorus in the mixer, it is injected into the circulating fluidized bed reactor from the top and returned to the reactor vessel from the bottom.

[0035] In this embodiment, the preparation process of the catalyst filler is as follows: polyvinylidene fluoride is dissolved in N,N-dimethylformamide solvent, a catalyst is added, and the mixture is stirred until uniformly dispersed. Then, a resin-based spherical activated carbon substrate is added, and the catalyst is fully adsorbed by ultrasonic vibration. Finally, the substrate is cured into a film to form the catalyst filler. The resin-based spherical activated carbon substrate has a particle size of 0.6-5 mm, a bulk density of 0.42-0.75 g / mL, an iodide value >800 mg / g, and is pre-treated by soaking in 5% electronic-grade nitric acid and washing with ultrapure water to remove impurities before drying. Key parameters during preparation include solution concentration (PVDF content 15%-20%), impregnation time (2-4 hours), curing temperature (60-80℃), total catalyst loading of 10%-20%, with an outer surface loading of 2%-5% on the substrate, and catalyst carbon spheres with a particle size of 0.6-6 mm and a bulk density of 0.6-0.8 g / mL. By loading the catalyst onto a resin-based spherical activated carbon substrate, the utilization and recycling rates of the catalyst are improved, and the introduction of yellow phosphorus as a new impurity is avoided, as well as catalyst loss is effectively prevented. The catalyst used is a solid powdered nano-metal-organic framework catalyst. Furthermore, the direct use of conventional catalysts, such as FeCl2 solution, is avoided, as its effectiveness is poor with large quantities and it can produce iron phosphate precipitation, reducing efficiency and potentially introducing new impurities.

[0036] In this embodiment, the material enters the circulating fluidized bed reactor via a top-in, bottom-out method. This configuration is because the density of the catalyst carbon spheres is much lower than that of yellow phosphorus (1.74 g / mL at 50°C). During the process, the material will undergo phase separation, with the aqueous phase on top. If bottom-up conveying is used, the aqueous phase will exit first, resulting in a lack of water seal for the yellow phosphorus, posing a safety hazard. The yellow phosphorus conveying pump has a flow rate of 0.08 m³ / mL. 3 / h, head 30m, motor power 2KW, motor speed 2850RPM. Peristaltic pump flow rate 0.006-2300mL / min, speed 0.2-500r / min. Example 2

[0037] The oxidant in Example 1 was replaced with 500 mL of 20% peracetic acid (PAA), while other reagents and operating procedures remained unchanged. Testing revealed that the total metal impurities in the yellow phosphorus were below 30 ppb, arsenic was 35 ppb, the yellow phosphorus yield was 97.8%, and CS2 insoluble matter was less than 0.5 ppm. Example 3

[0038] The oxidant in Example 1 was replaced with 500 mL of 20% permonosulfate (PMS), while other reagents and operating procedures remained unchanged. Testing revealed that the total metal impurities in the yellow phosphorus were below 30 ppb, arsenic was 22 ppb, the yellow phosphorus yield was 98.2%, and CS2 insoluble matter was less than 0.5 ppm. Example 4

[0039] In Example 3, the reaction time was extended to 10 hours, while other reagents and operating steps remained unchanged. The purified yellow phosphorus was tested and found to have a total metal impurity content of less than 20 ppb, an arsenic content of 8 ppb, a yellow phosphorus yield of 97.6%, and CS2 insoluble matter of less than 0.5 ppm. Example 5

[0040] The catalyst supported on the catalyst bed in Example 3 was replaced with an equal volume of FeMo-MOFs carbon spheres, while other reagents and operating procedures remained unchanged. Testing revealed that the total metal impurities in the yellow phosphorus were less than 20 ppb, arsenic was 9 ppb, the yellow phosphorus yield was 97.7%, and CS2 insoluble matter was less than 0.5 ppm. Example 6

[0041] The oxidant in Example 1 was replaced with 500 mL of 20% diisopropyl peroxide carbonate emulsion, while other reagents and operating procedures remained unchanged. Testing revealed that the total metal impurities in the yellow phosphorus were below 20 ppb, arsenic was 28 ppb, the yellow phosphorus yield was 98.3%, and CS2 insoluble matter was less than 0.5 ppm. Example 7

[0042] The catalyst supported on the catalyst bed in Example 1 was replaced with an equal volume of Fe-MOF carbon spheres, while other reagents and operating procedures remained unchanged. Testing revealed that the total metal impurities in the yellow phosphorus were less than 50 ppb, arsenic was 48 ppb, the yellow phosphorus yield was 95.1%, and CS2 insoluble matter was less than 0.5 ppm. Example 8

[0043] The catalyst in the catalyst bed supported in Example 1 was replaced with an equal volume of FeCl2 carbon sphere packing material, while other reagents and operating procedures remained unchanged. Testing revealed that the total metal impurities in the yellow phosphorus were less than 100 ppb, arsenic was 172 ppb, the yellow phosphorus yield was 94.7%, and CS2 insoluble matter was less than 0.5 ppm.

[0044] Comparative Example 1

[0045] After stirring and rinsing the yellow phosphorus in Example 1 to remove incompatible impurities such as ash and coke floating on its surface, without starting the circulating fluidized bed reactor system, 20% nitric acid oxidant was slowly added to the reactor. After stirring until homogeneous, 20% FeCl2 solution was slowly added dropwise. Finally, the amount of 20% nitric acid added was 0.6 L, and the FeCl2 solution (Fe...) was added... 2+ The amount of yellow phosphorus (20% concentration) was 200 mL. The subsequent rinsing process followed the final rinsing process of Example 1. Finally, the total metal impurities in the yellow phosphorus were tested to be less than 100 ppb, arsenic was 1.28 ppm, the yellow phosphorus yield was 95.4%, and CS2 insoluble matter was less than 5 ppm.

[0046] Comparative Example 2

[0047] The oxidant in Comparative Example 1 was replaced with 500 mL of 20% permonosulfate (PMS), and all other operations were performed in accordance with Comparative Example 1. The total metal impurities in the yellow phosphorus were found to be less than 100 ppb, arsenic was 0.86 ppm, the yellow phosphorus yield was 96.7%, and CS2 insoluble matter was less than 5 ppm.

[0048] Comparative Example 3

[0049] The catalyst in Comparative Example 2 was replaced with an equal volume of FeMo-MOFs, and all other operations were performed in the same manner as in Comparative Example 2. Analysis showed that the total metal impurities in the yellow phosphorus were less than 100 ppb, arsenic was 0.12 ppm, the yellow phosphorus yield was 96.3%, and CS2 insoluble matter was less than 5 ppm.

[0050] The above embodiments and comparative examples are summarized in the following table:

[0051] Table 1. Comparison of products obtained under different processing conditions

[0052]

[0053] As shown in Table 1, the yellow phosphorus prepared in the embodiments of the present invention achieves a purity of 6N-7N; arsenic content ≤60ppb, with an optimal content of 8ppb, and an arsenic removal efficiency of 99%; total metals ≤50ppb, even less than 20ppb; and CS2 insoluble matter is less than 0.5ppm. In contrast, the purification effect of yellow phosphorus in the comparative examples is quite poor.

[0054] The specific analysis is as follows:

[0055] (1) Highly efficient and specialized catalysts are essential for the efficient purification of yellow phosphorus. The metal-organic framework materials used in the catalysts possess stability and reusability, highly efficient catalytic activation, optimized free radical generation pathways, and multifunctional synergistic effects. For example, Fe-MOFs (iron-based metal-organic frameworks) activate persulfates (such as PMS) in a Fenton-like manner through heterogeneous catalytic activation, compared to Fe alone. 2+ Fe-MOFs offer advantages for PMS activation: their high specific surface area and tunable pore structure provide more active sites, significantly improving PMS activation efficiency; Fe-MOFs regulated through trap engineering can enable Fe... 3+ / Fe 2+ The cycle efficiency was increased by 23.7 times, accelerating electron transfer, free radical generation, and the production of high-valence active species, thus enhancing the catalytic effect. In particular, bimetallic FeMo-MOFs exhibited a multifunctional synergistic effect, demonstrating optimal catalytic efficiency. For example, Examples 5 and Comparative Example 3 showed the best performance within their respective groups. In contrast, conventional Fe alone... 2+Solution catalysts are prone to oxidation, lack reusability, or may react with other substances, leading to a decrease in catalytic activity. Of course, the choice of oxidant is also crucial. For example, Example 3 uses persulfate (PMS), an oxidant with a Fenton-like reaction, which is significantly superior to the simple oxidant nitric acid used in Example 1.

[0056] (2) The role of the circulating fluidized bed reactor system is very important. The effects of the examples and the comparative examples are significantly different, the biggest difference being the different processes used. The comparative example uses a simple reactor to treat yellow phosphorus, which can only increase the contact area between the aqueous phase of yellow phosphorus and the aqueous phase containing the oxidant by stirring, thereby increasing the reaction rate. However, stirring alone cannot achieve efficient mixing of the aqueous phase of yellow phosphorus and the aqueous phase containing the oxidant. The examples use a circulating fluidized bed reactor system, which not only allows the yellow phosphorus and oxidant solution to collide fully through the efficient mixing unit, forming fine particles, which can greatly increase the contact area with the catalyst, but also, due to the huge density difference between the two (the density of yellow phosphorus at 50℃ is 1.74 g / mL, and the density of the catalyst carbon balls is 0.6-0.8 g / mL), the catalyst carbon balls continuously sink and float under the impact of the jet flow from top to bottom, realizing the dynamic fluidized bed effect, increasing the probability of contact between the nano-catalyst and yellow phosphorus and oxidant, so the effect is significantly improved.

[0057] (3) In addition to promoting the entry of floatable impurities such as coke, ash and insoluble phosphate into the aqueous phase through adsorption, debinding and complexation, the rinsing agent also has the ability to form water-soluble complexes with metal ions for removal.

[0058] (4) The process of the present invention has the advantages of non-high temperature conditions, safe operation and low energy consumption.

[0059] It is evident that this invention patent employs a coupled process of highly efficient dedicated catalyst, circulating fluidized bed reaction, and complexation rinsing, ultimately achieving significant results in the purification of yellow phosphorus to remove metal impurities and arsenic.

[0060] The methods and products of this invention have been described through preferred embodiments. Those skilled in the art will readily be able to modify or appropriately alter and combine the methods and products described herein without departing from the content, spirit, and scope of this invention to achieve the technical benefits of this invention. It should be particularly noted that the practicality of this invention in terms of the operability of process equipment, the controllability of process safety risks, and energy saving and cost reduction, as well as the obvious improvements to the technology in the art from all similar substitutions and modifications, are considered to be included within the spirit, scope, and content of this invention.

Claims

1. A method for preparing high-purity yellow phosphorus, characterized in that: Includes the following steps: (1) Add pure water to the reactor, and under heat preservation conditions, add liquefied industrial yellow phosphorus, turn on the stirrer in the reactor, and repeatedly rinse the liquefied industrial yellow phosphorus to remove floating impurities. (2) After rinsing, the yellow phosphorus is thoroughly mixed with the oxidant through a mixer and then introduced into a circulating fluidized bed reactor equipped with a catalyst bed. The mixture of yellow phosphorus and oxidant is in full contact with the catalyst packing in the catalyst bed to carry out an oxidation-reduction reaction. (3) After the redox reaction is completed, the yellow phosphorus flows back from the circulating fluidized bed reactor into the reactor, and then the yellow phosphorus that flows back into the reactor is pumped into the circulating fluidized bed reactor to circulate the above redox reaction. (4) After the reaction is complete, the liquefied industrial yellow phosphorus in the reactor is allowed to stand and separate into layers to remove floating impurities, separate the refined yellow phosphorus, and then rinse with high-purity water to obtain high-purity yellow phosphorus. The oxidizing agent is one or two of the following: persulfate, perdisulfate, peracetic acid, chlorate, nitric acid, m-chloroperoxybenzoic acid, Dys-Martin reagent, and diisopropyl peroxycarbonate. The catalysts supported in the catalyst packing are Mn-MoFs, Ce-MOFs, Fe-MOFs, FeMo-MOFs, ZnP-COF, CuP-COF, and Fe. 0 One or two of -COF102; The rinsing agent added during rinsing in step (1) is one or two of the following high-purity aqueous solutions: polymethoxyphosphoric acid, phosphoric acid, polyether polyol, aminodimethylphosphonic acid, and ethylenediaminetetraacetic acid.

2. The method for preparing high-purity yellow phosphorus according to claim 1, characterized in that: The volume of the oxidant added is 10%-30% of the volume of yellow phosphorus, the volume of the catalyst added is 5%-10% of the volume of yellow phosphorus, and the volume of the rinsing agent added is 5%-10% of the volume of yellow phosphorus.

3. The method for preparing high-purity yellow phosphorus according to claim 1, characterized in that: The catalyst is loaded onto a resin-based spherical activated carbon matrix via polyvinylidene fluoride to form a catalyst filler. The total catalyst loading is 10%-20%, and the outer surface loading of the resin-based spherical activated carbon matrix is ​​2%-5%. The catalyst carbon spheres in the catalyst filler have a particle size of 0.6-6 mm and a bulk density of 0.6-0.8 g / mL.

4. The method for preparing high-purity yellow phosphorus according to claim 1, characterized in that: The mixer includes a pipeline static mixer or a jet pump mixer.

5. The method for preparing high-purity yellow phosphorus according to claim 1, characterized in that: The circulating fluidized bed reactor includes a bed, a catalyst bed, a partition plate, a discharge port, and a reactor wall, and has the functions of enhanced mass transfer through liquid-solid circulation and continuous regeneration of the catalyst bed.

6. The method for preparing high-purity yellow phosphorus according to claim 1, characterized in that: The temperature of the reactor is 50-70℃, and the cycle reaction time is 5-10 hours.

7. The method for preparing high-purity yellow phosphorus according to claim 1, characterized in that: Throughout the entire production process, the yellow phosphorus in the reactor is covered with pure water, with the water level at least 10 cm below the surface of the yellow phosphorus solution.

8. The method for preparing high-purity yellow phosphorus according to claim 1, characterized in that: In step (2), before adding yellow phosphorus and oxidant into the circulating fluidized bed reactor, the reactor is filled with pure water and the air is removed.

9. The method for preparing high-purity yellow phosphorus according to claim 3, characterized in that: The preparation process of the catalyst filler is as follows: polyvinylidene fluoride is dissolved in N,N-dimethylformamide solvent, the catalyst is added, and the mixture is stirred until it is evenly dispersed. Then, resin-based spherical activated carbon substrate is added, and the catalyst is fully adsorbed by ultrasonic vibration. Finally, the mixture is cured into a film to form the catalyst filler. The resin-based spherical activated carbon substrate has a particle size of 0.6-5 mm, a bulk density of 0.42-0.75 g / mL, an iodine value of >800 mg / g, and is pre-soaked in 5% electronic grade nitric acid and washed with ultrapure water to remove impurities before drying.

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