A simple and efficient integrated potassium ferrate preparation device and method

Abstract

The invention discloses a simple and efficient integrated potassium ferrate preparation device and method, which relates to the technical field of solid potassium ferrate preparation, and comprises: a mixing box, which can mix sodium hypochlorite solution with potassium hydroxide solution to form an alkaline sodium hypochlorite solution, a preparation box which can mix alkaline sodium hypochlorite solution with trivalent iron solid powder to form a potassium ferrate solution, a centrifugal filter device which can centrifugally filter the potassium ferrate solution to form a filtrate and a potassium ferrate solid raw material, the potassium ferrate solid raw material is mixed with an alkali solution in a solid collector to form a potassium ferrate solid coarse material, a purification device which can rinse the potassium ferrate solid coarse material to form a potassium ferrate solid fine material, and a drying device which can dry the potassium ferrate solid fine material to form a potassium ferrate solid product. The invention simplifies the preparation process, reduces the maintenance time caused by the independence difference between the equipment, improves the preparation efficiency, improves the purity and product quality of the potassium ferrate solid, and saves the preparation cost.

Description

Technical Field

[0001] The invention relates to the technical field of solid potassium ferrate preparation, and in particular to a simple and efficient integrated potassium ferrate preparation device and method. Background Art

[0002] Potassium ferrate is a green water treatment agent that can effectively degrade pharmaceuticals and personal care products. It also has multiple functions such as removing heavy metals, improving sludge decomposition, controlling membrane fouling and pretreating algae water. However, the preparation cost of potassium ferrate is high, the product is unstable and easily decomposed, and large-scale industrial preparation has not been achieved.

[0003] At present, there are three main methods for preparing potassium ferrate: chemical dry method (melting method), chemical wet method (hypochlorite oxidation method) and electrochemical oxidation method (electrolysis method). Among them, the chemical dry method has high requirements on preparation conditions, requires a specific high temperature and high pressure environment, and the purity of the prepared potassium ferrate is not high; in the preparation process of the electrochemical oxidation method, as the reaction time increases, a passivation film will slowly form on the surface of the anode electrode, affecting further electrolysis, and the yield of potassium ferrate is low; the chemical wet method is to obtain potassium ferrate by oxidizing iron ions with hypochlorite in a strong alkaline environment. The energy consumption of this process is low, the yield is high, and the corrosion resistance requirements of the reaction equipment are low, which is more suitable for laboratory scale and industrial production scale preparation.

[0004] The existing chemical wet preparation process is complicated, and the independence of each link device is poor. When maintenance is required at a certain point, the entire process equipment often needs to be stopped, which affects the preparation efficiency. At the same time, the preparation process usually requires the preparation of a high-concentration sodium ferrate solution, and then converting it into potassium ferrate solid. The potassium ferrate obtained by the initial crystallization has low purity, and a recrystallization process needs to be added to obtain high-purity solid potassium ferrate. In addition, the amount of rinse agent required for the purification of potassium ferrate is large, and the process operation is cumbersome, which increases the preparation cost. A large amount of waste liquid is generated during the preparation process, which is difficult to deal with in a timely and effective manner.

[0005] Invention patent CN110449109A discloses a continuous preparation device for ferrate, which improves the oxidation efficiency of sodium hypochlorite solution, accelerates solution mixing, and enhances preparation efficiency through coils and ultrasonic generators, but the limitations of pipelines and liquid flow rates make some reactions inadequate. Utility model patent CN219129274U discloses a potassium ferrate production system, which is divided into four subsystems for operation, resulting in a complicated preparation process. Invention patent CN102161513A discloses a method for preparing potassium ferrate with low cost, fast preparation speed and high safety. It uses 10-20 mol / L potassium hydroxide instead of saturated potassium hydroxide for recrystallization process, which saves raw materials, but does not change the conversion of sodium ferrate to potassium ferrate and the recrystallization process, and the preparation process is cumbersome. Invention patent CN115947376A discloses a stable and efficient method for preparing potassium ferrate, which uses chlorine to prepare potassium hypochlorite, which has low stability and increases the risk and cost, and the potassium ferrate impurities precipitated initially are relatively large.

[0006] In summary, the existing technology has not yet solved the problems of complex chemical wet preparation process, low preparation efficiency and high preparation cost. In view of this, how to provide a chemical wet preparation method for potassium ferrate with high efficiency, low cost and simple process to achieve effective preparation of solid potassium ferrate is a problem that technical personnel in this field urgently need to solve. Summary of the invention

[0007] The purpose of the present invention is to provide a simple and efficient integrated potassium ferrate preparation device and method, which can prepare potassium ferrate by a chemical wet method with high efficiency, low cost and simple process, realize the effective preparation of solid potassium ferrate, and solve the problems existing in the prior art.

[0008] To achieve the above object, the present invention provides the following solution: The present invention provides a simple and efficient integrated potassium ferrate preparation device, comprising:

[0009] A mixing box, the mixing box is connected to the sodium hypochlorite solution storage tank and the potassium hydroxide solution storage tank respectively, and the mixing box can mix the sodium hypochlorite solution and the potassium hydroxide solution to form an alkaline sodium hypochlorite solution;

[0010] A preparation box, the preparation box is connected to the mixing box and the ferric iron storage box respectively, and the preparation box can mix the alkaline sodium hypochlorite solution with the ferric iron solid powder to form a potassium ferrate solution;

[0011] A centrifugal filter device, the centrifugal filter device is connected to the preparation box, the centrifugal filter device can centrifugally filter the potassium ferrate solution to form a filtrate and a potassium ferrate solid raw material, the centrifugal filter device has a discharge pipe and a solid discharge pipe, the filtrate is discharged through the discharge pipe, the potassium ferrate solid raw material is discharged into a solid collector through the solid discharge pipe, the solid collector is filled with alkali solution, the potassium ferrate solid raw material is mixed with the alkali solution in the solid collector, and is left to stand to form a potassium ferrate solid coarse material;

[0012] A purification device, the purification device is connected to the centrifugal filtering device, the purification device has a circulation pump, the circulation pump can suck the potassium ferrate solid coarse material into the purification device, and the purification device can rinse the potassium ferrate solid coarse material to form potassium ferrate solid fine material;

[0013] A drying device is provided, wherein the drying device is capable of drying the potassium ferrate solid fine material to form a potassium ferrate solid product.

[0014] Furthermore, the potassium hydroxide solution storage tank is located in the mixing tank, and the potassium hydroxide solution storage tank and the sodium hypochlorite solution storage tank are both connected to the mixing tank through a liquid inlet pipe, and a peristaltic pump is provided on the liquid inlet pipe.

[0015] Furthermore, a filter layer is provided on the bottom surface of the mixing box and at the connection point between the mixing box and the preparation box. The filter layer is made of glass fiber and has a thickness of 8-20 mm.

[0016] Furthermore, a magnetic stirrer and a first ultrasonic device are provided in the preparation box, and a temperature control device is provided on the outer surface of the preparation box, and the temperature control device can maintain the internal temperature of the preparation box at 5-10°C.

[0017] Furthermore, the ferric iron storage tank has a grinding device, which can grind the ferric iron solid to form ferric iron solid powder.

[0018] Furthermore, the centrifugal filter device comprises:

[0019] A centrifugal chamber, the centrifugal chamber is connected to the preparation box, and a centrifugal shaft is arranged at the bottom center of the centrifugal chamber; one end of the solid discharge pipe is connected to the bottom of the centrifugal chamber, the connection point is spaced from the centrifugal shaft, and the other end is connected to the solid collector;

[0020] An outer cavity, the outer cavity is arranged outside the centrifugal cavity, the centrifugal cavity is provided with through holes through the inner and outer surfaces, the inner wall of the centrifugal cavity is covered with a filter cloth covering the through holes, one end of the drain pipe is connected with the outer cavity, the connection point is close to the top of the centrifugal cavity, and the other end extends outward;

[0021] A scraper is driven by a pneumatic device and is provided with an infrared sensor, which can detect the thickness of the potassium ferrate solid coarse material on the inner wall and / or the bottom of the centrifugal chamber; when the thickness of the potassium ferrate solid coarse material on the inner wall and / or the bottom of the centrifugal chamber reaches a preset value, the scraper can scrape the potassium ferrate solid coarse material on the inner wall and the bottom of the centrifugal chamber into the solid collector.

[0022] Furthermore, the purification device comprises:

[0023] A purification chamber, wherein the purification chamber is connected to the centrifugal cavity through a connecting pipe, the circulating pump is arranged on the connecting pipe, and a second ultrasonic device is arranged in the purification chamber;

[0024] an organic solvent storage box, the organic solvent storage box being in communication with the purification chamber and filled with an organic solvent;

[0025] The tray has multiple layers and is evenly spaced from top to bottom. The potassium ferrate solid coarse material is sucked into the tray by a circulation pump and a connecting pipe. The organic solvent storage tank can transport the organic solvent to the tray and rinse the potassium ferrate solid coarse material.

[0026] The present invention also provides a simple and efficient integrated preparation method of potassium ferrate, comprising the following steps:

[0027] S1: pumping a sodium hypochlorite solution and a potassium hydroxide solution into a mixing tank, and mixing them in the mixing tank to form an alkaline sodium hypochlorite solution;

[0028] S2: feeding the ferric iron fixed powder and the alkaline sodium hypochlorite solution into a preparation box, and mixing them in the preparation box by a magnetic stirrer and a first ultrasonic device to form a potassium ferrate solution;

[0029] S3: The potassium ferrate solution enters a centrifugal filter device, is separated by a centrifugal shaft to form a filtrate and a potassium ferrate solid raw material, the filtrate is discharged through a discharge pipe, and the potassium ferrate solid raw material is discharged into a solid collector through a solid discharge pipe. The solid collector is filled with alkali solution, and the potassium ferrate solid raw material is mixed with the alkali solution in the solid collector and allowed to stand to form a potassium ferrate solid crude material;

[0030] S4: The potassium ferrate solid crude material is sucked from the solid collector into the purification chamber through a circulation pump and a connecting pipe, an organic solvent is introduced into the purification chamber, and the potassium ferrate solid crude material is rinsed by the organic solvent and the second ultrasonic device until the potassium ferrate solid crude material at the bottom of the purification chamber turns purple-black without other colors, thereby forming potassium ferrate solid fine material;

[0031] S5: placing the rinsed potassium ferrate solid fine material into a drying device, and obtaining a potassium ferrate solid product after drying.

[0032] Furthermore, the sodium hypochlorite solution is a sodium hypochlorite solution with an effective chlorine content of 8%-20%, the stoichiometric ratio of the sodium hypochlorite to the trivalent iron fed into the preparation box is 5-10, and the trivalent iron fixed powder is fed into the preparation box in a multiple-time manner.

[0033] Furthermore, the organic solvents include ethanol, n-hexane, n-pentane, methanol and ether; during rinsing, the potassium ferrate solid crude material is firstly rinsed with ethanol and a second ultrasonic device, and then with n-hexane, n-pentane, methanol, ether and a second ultrasonic device.

[0034] The present invention discloses the following technical effects:

[0035] 1. The present invention provides an integrated potassium ferrate solid product preparation device, which simplifies the preparation process, reduces the maintenance time caused by the independence differences between equipment, improves the preparation efficiency, and reduces the use of multi-link independent equipment through continuous structural design, making the entire preparation process smoother and simpler.

[0036] 2. Through the use of centrifugal filtering devices, purification devices and ultrasonic devices, the reaction process is optimized, the purity and product quality of potassium ferrate solid are improved, and the preparation cost is saved.

[0037] 3. Potassium hydroxide and sodium hypochlorite are mixed to form an alkaline sodium hypochlorite solution. No recrystallization is required during the preparation process, which simplifies the process, saves costs, increases economic benefits, environmental benefits and the feasibility of technical solutions, and lays the foundation for large-scale preparation. Potassium ferrate is prepared by an efficient, low-cost and simple chemical wet method to achieve effective preparation of solid potassium ferrate.

[0038] 4. No waste liquid is generated during the preparation process: The waste liquid of this method is mainly the filtrate produced after centrifugal filtration. The filtrate has a relatively high iron content. Potassium ferrate solid can be precipitated by further adding solid potassium hydroxide to increase its output rate. It can also be used in the recrystallization process of low-purity potassium ferrate solid. It can also be used in the pre-treatment stage of some specific wastewater to reasonably circulate the waste liquid and effectively utilize it.

[0039] 5. This method is simple and convenient, the experimental conditions are mild, and it can achieve rapid on-site preparation. At the same time, it can meet different preparation needs. It has low maintenance costs and can achieve the target output with a small amount of initial investment. It has good operability and controllability. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0041] Figure 1 It is a schematic diagram of the structure of the present invention;

[0042] Figure 2 It is a schematic diagram of the structure of a centrifugal filter device;

[0043] Figure 3 The graphs are the spectrum curves of homemade potassium ferrate and commercially available potassium ferrate;

[0044] Figure 4 This is the removal efficiency diagram of homemade potassium ferrate and commercial potassium ferrate for phenol;

[0045] Among them, 1. shell; 2. trivalent iron storage box; 3. grinding device; 4. motor; 5. temperature control layer; 6. sodium hypochlorite solution storage box; 7. control device; 8. liquid temporary storage layer; 9. flow pump; 10. preparation box; 11. mixing box; 12. feed pipe; 13. circulation pump; 14. centrifugal filtration device; 15. drainage pipe; 16. drainage pump; 17. organic solvent storage box; 18. purification device; 19. drying device; 20. pneumatic device; 21. filter cloth; 22. solid discharge pipeline; 23. solid collector; 24. centrifugal shaft; 25. scraper; 26. centrifugal cavity; 27. outer cavity. DETAILED DESCRIPTION

[0046] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0047] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0048] Example 1

[0049] like Figure 1 and Figure 2As shown, the embodiment of the present invention provides a simple and efficient integrated potassium ferrate preparation device, including: a mixing box 11 integrated in the same shell 1, the mixing box 11 is connected to the sodium hypochlorite solution storage tank 6 and the potassium hydroxide solution storage tank respectively, and the mixing box 11 can mix the sodium hypochlorite solution and the potassium hydroxide solution to form an alkaline sodium hypochlorite solution; a preparation box 10, the preparation box 10 is connected to the mixing box 11 and the ferric iron storage tank 2 respectively, the ferric iron storage tank 2 has a grinding device 3, and the grinding device 3 has a motor 4, which can grind the ferric iron solid to form ferric iron solid powder. The preparation box 10 can mix the alkaline sodium hypochlorite solution with the trivalent iron solid powder to form a potassium ferrate solution; the centrifugal filter device 14 is connected to the preparation box 10, and the centrifugal filter device 14 can centrifugally filter the potassium ferrate solution to form a filtrate and a potassium ferrate solid raw material. The centrifugal filter device 14 has a drain pipe 15 and a solid discharge pipeline 22. The filtrate is discharged through the drain pipe 15, and the potassium ferrate solid raw material is discharged into the solid collector 23 through the solid discharge pipeline 22. The solid collector 23 is filled with Alkali solution, potassium ferrate solid raw material is mixed with alkali solution in solid collector 23 and left to stand to form potassium ferrate solid coarse material; purification device 18, purification device 18 is connected with centrifugal filter device 14, purification device 18 has circulation pump 13, circulation pump 13 can suck potassium ferrate solid coarse material into purification device 18, purification device 18 can rinse potassium ferrate solid coarse material to form potassium ferrate solid fine material; drying device 19, drying device 19 can dry potassium ferrate solid fine material to form potassium ferrate solid product.

[0050] In this embodiment, the potassium hydroxide solution storage tank is located in the mixing tank 11, and the potassium hydroxide solution storage tank and the sodium hypochlorite solution storage tank 6 are both connected to the mixing tank 11 through a liquid inlet pipe, a peristaltic pump is provided on the liquid inlet pipe, and a solution temporary storage layer and a flow pump 9 are provided between the sodium hypochlorite solution storage tank 6 and the liquid inlet pipe, which are used to accurately control the flow of potassium hydroxide entering the mixing tank 11.

[0051] In this embodiment, a filter layer is provided on the bottom surface of the mixing box 11 and at the connection point between the mixing box 11 and the preparation box 10. The filter layer is made of glass fiber and has a thickness of 8-20 mm. The pores of the filter layer on the bottom surface are larger than the pores of the filter layer at the connection point. The filter layer at the connection point can effectively prevent solid impurities from entering the preparation box 10, avoid clogging the pipeline, and reduce product impurities. The filter layer on the bottom surface is used to carry solids precipitated during the mixing process of the sodium hypochlorite solution and the potassium hydroxide solution.

[0052] In this embodiment, a magnetic stirrer and a first ultrasonic device are provided in the preparation box 10, and a temperature control device is provided on the outer surface of the preparation box 10. When the preparation box 10 prepares a high-concentration potassium ferrate solution, the magnetic stirrer is mainly used to ensure that the reaction is fully carried out, but the efficiency is low, and as the reaction time increases, the viscosity of the solution gradually increases, the stirring resistance becomes larger, the stirring rate becomes slower, and the efficiency of the stirrer further decreases. In order to improve the preparation efficiency, this embodiment is provided with a first ultrasonic device in the middle of the device, which can increase the disturbance of the solution, accelerate the reaction, and improve the preparation yield. The temperature control device is composed of a heating layer and a control device 7. The temperature of the heating layer is controlled by the control device 7. A temperature sensor or other sensing component can be provided in the preparation box 10 so that the internal temperature of the preparation box 10 is maintained at 5-10°C. The high-concentration potassium ferrate solution is in a colloidal state, and the solution contains a large amount of iron oxides. The traditional suction filtration method is inefficient, so the centrifugal filtration technology is introduced to accelerate the separation of solid and liquid. At the same time, the centrifugal temperature needs to be controlled during centrifugal filtration to increase the stability of potassium ferrate.

[0053] In this embodiment, the centrifugal filtration device 14 includes: a centrifugal cavity 26, the centrifugal cavity 26 is connected to the preparation box 10 through the feed pipe 12, and a centrifugal shaft 24 is arranged at the bottom center of the centrifugal cavity 26; one end of the solid discharge pipe 22 is connected to the bottom of the centrifugal cavity 26, and the connection point is spaced apart from the centrifugal shaft 24, and the other end is connected to the solid collector 23; an outer cavity 27, the outer cavity 27 is arranged outside the centrifugal cavity 26, and the centrifugal cavity 26 is provided with through holes through the inner and outer surfaces, and the inner side wall of the centrifugal cavity 26 is covered with a filter cloth 21, and a liquid discharge pipe One end of the centrifugal shaft 24 is connected to the outer cavity 27, and the connection point is close to the top of the centrifugal cavity 26, and the other end extends outward; the scraper 25 is driven by the pneumatic device 20, and the scraper 25 is provided with an infrared sensor, which can detect the thickness of the potassium ferrate solid coarse material on the inner wall and / or the bottom of the centrifugal cavity 26; when the thickness of the potassium ferrate solid coarse material on the inner wall and / or the bottom of the centrifugal cavity 26 reaches a preset value, the centrifugal shaft 24 slows down, and at this time, the scraper 25 can scrape the potassium ferrate solid coarse material on the inner wall and the bottom of the centrifugal cavity 26 into the solid collector 23. An electric control valve can be provided at the connection point between one end of the solid discharge pipe 22 and the centrifugal cavity 26. The electric control valve is closed during the centrifugation process. Under the action of centrifugation, the potassium ferrate solution is centrifugally filtered to form a filtrate and a potassium ferrate solid raw material. The filtrate passes through the filter cloth 21 and the through hole and enters the outer cavity 27. The outer cavity 27 has a certain volume. When the filtrate accumulates a certain volume in the outer cavity 27, the liquid level of the filtrate reaches the drain pipe 15 and is discharged through the drain pump 16 and the drain pipe 15. The filtrate can be further precipitated with solid potassium ferrate by slowly adding potassium hydroxide in an ice water bath. It can also be used for the preliminary treatment of some sewage, to adjust the pH value of the solution and to preliminarily eliminate the pollutants therein, so as to use it reasonably and effectively, so that no waste liquid is generated during the preparation process.

[0054] In this embodiment, the purification device 18 includes: a purification chamber, the purification chamber is connected to the centrifugal cavity 26 through a connecting pipe, the circulation pump 13 is arranged on the connecting pipe, and a second ultrasonic device is arranged in the purification chamber; an organic solvent storage box 17, the organic solvent storage box 17 is connected to the purification chamber, and the organic solvent storage box 17 is filled with organic solvent; a tray, the tray has multiple layers and is evenly spaced from top to bottom, the connecting pipe can be set to multiple and correspond to the multi-layer trays one by one, the potassium ferrate solid coarse material is sucked into each layer of the tray through the circulation pump 13 and the connecting pipe; the organic solvent storage box 17 can transport the organic solvent to the tray through the spray device and spray the potassium ferrate solid coarse material in each layer of the tray. The purification chamber has a liquid outlet, which can be used to discharge the organic solvent for rinsing, and the liquid outlet is provided with an electric control valve.

[0055] The present invention also provides a simple and efficient integrated preparation method of potassium ferrate, comprising the following steps:

[0056] S1: Pumping the sodium hypochlorite solution and the potassium hydroxide solution into the mixing box 11, and mixing them in the mixing box 11 to form an alkaline sodium hypochlorite solution;

[0057] In S1, the sodium hypochlorite solution is a sodium hypochlorite solution with an effective chlorine content of 8%-20%, which replaces the complex process of preparing chlorine gas by on-site process and passing it into sodium hydroxide solution to prepare sodium hypochlorite, simplifies the preparation process, reduces the use of chlorine gas, and improves safety. Commercially available sodium hypochlorite solution is more stable than homemade sodium hypochlorite solution, which is conducive to the efficient and continuous preparation of potassium ferrate; homemade sodium hypochlorite solution, affected by the concentration of chlorine gas and sodium hydroxide, cannot guarantee the stability of its effective chlorine during the preparation process, and its concentration fluctuates greatly, which affects the preparation of potassium ferrate. In sodium hypochlorite solution, the effective chlorine concentration cannot be too low. If the effective chlorine concentration is too low, potassium ferrate cannot be effectively prepared. Sodium hypochlorite solution with too high effective chlorine concentration has high production and transportation costs. At the same time, the heat generated during the reaction process consumes more significant amounts of high-concentration effective chlorine. Therefore, taking all factors into consideration, using a sodium hypochlorite solution with an effective chlorine content between 8% and 20% can ensure the effective production of potassium ferrate and save preparation costs.

[0058] Potassium hydroxide is used to create a strong alkaline environment. Compared with sodium hydroxide as an alkaline solution, both are strongly alkaline, but the potassium salt produced by the reaction of potassium hydroxide in the solution has low solubility and is easier to precipitate solids. Potassium hydroxide can be dissolved in organic solvents such as ethanol, which is convenient for subsequent rinsing. If solid sodium hydroxide is used instead, the solubility of the final product, sodium ferrate, in water is greater than that of potassium ferrate. In order to obtain a solid phase product, potassium hydroxide needs to be added to the sodium ferrate solution and converted into potassium ferrate through a recrystallization process. Therefore, using potassium hydroxide as an alkaline solution can effectively reduce the complexity of the process and the preparation cost.

[0059] S2: feeding the ferric iron fixed powder and the alkaline sodium hypochlorite solution into the preparation box 10, and mixing them in the preparation box 10 by a magnetic stirrer and a first ultrasonic device to form a potassium ferrate solution;

[0060] In S2, the stoichiometric ratio of sodium hypochlorite and ferric iron fed into the preparation box 10 is 5-10. It is found through experiments that in the process of preparing potassium ferrate, as the addition ratio of sodium hypochlorite to ferric iron increases, the output of potassium ferrate prepared gradually increases. This is because the stability of the sodium hypochlorite solution is poor and it decomposes faster in a solution with lower alkalinity, which reduces the utilization rate of hypochlorite. Increasing the addition ratio can effectively increase the amount of available sodium hypochlorite, but the increase in the addition ratio will also increase the cost of sodium hypochlorite. Therefore, considering comprehensively, it is best to control the stoichiometric ratio between 5-10, and the method can achieve control of the preparation output through proportional scaling. The ferric iron fixed powder is fed into the preparation box 10 in a multiple-time feeding manner, with a small amount being fed each time. If the feeding is too fast, the ferric hydroxide content in the solution will be too high. At the same time, the reaction in which the ferric iron participates is an exothermic reaction, and the increase in the solution temperature increases the ineffective decomposition of the sodium hypochlorite. Therefore, the reaction temperature needs to be controlled when the ferric iron is added, and the feeding time is controlled within 25 minutes. During the feeding process, the solution gradually turns purple-black, and as the reaction time increases, the color gradually deepens.

[0061] S3: The potassium ferrate solution enters the centrifugal filter device 14, and is separated by the centrifugal shaft 24 to form a filtrate and a potassium ferrate solid raw material. The filtrate is discharged through the drain pipe 15, and the potassium ferrate solid raw material is discharged into the solid collector 23 through the solid discharge pipe 22. The solid collector 23 is filled with alkali solution. The potassium ferrate solid raw material is mixed with the alkali solution in the solid collector 23 and is left to stand for 30 minutes to form a potassium ferrate solid crude material.

[0062] S4: The potassium ferrate solid crude material is sucked from the solid collector 23 into the purification chamber through the circulation pump 13 and the connecting pipe (actually, it is first sucked into the centrifugal filter device 14 and then sucked into the purification chamber), and an organic solvent is introduced into the purification chamber. The potassium ferrate solid crude material is rinsed by the organic solvent and the second ultrasonic device until the potassium ferrate solid crude material at the bottom of the purification chamber is purple-black and has no other colors, thereby forming potassium ferrate solid fine material;

[0063] In S4, the initial rinse agent is cheap anhydrous ethanol. Under the action of ultrasonic oscillation, other iron oxides in the potassium ferrate solid crude material are removed, and high-purity potassium ferrate solid can be obtained without recrystallization. At the same time, most of the impurities in the product can be removed through the initial ultrasonic rinse, reducing the use of subsequent organic solvents and saving costs. Ultrasonic waves are used to promote the dissolution of impurities such as potassium hydroxide and iron oxides in the product in ethanol, speed up the rinse process, make the preparation process simpler, reduce costs, and reduce the consumption of organic solvents. After the initial rinse is completed, the electric control valve at the liquid outlet is opened to discharge the ethanol.

[0064] The organic solvents used to further purify the potassium ferrate solid are n-hexane, n-pentane, methanol and diethyl ether. The purification process is to first rinse twice with n-hexane, then rinse twice with n-pentane, then rinse twice with methanol, and finally rinse twice with diethyl ether. Among them, n-hexane and n-pentane are used to remove impurities such as salt in the water, methanol is used to remove n-hexane and n-pentane, and diethyl ether is used to remove water and dry.

[0065] S5: The rinsed potassium ferrate solid fine material is placed in a drying device 19, and a potassium ferrate solid product is obtained after drying.

[0066] In the above method, the chemical stoichiometric ratio of sodium hypochlorite to ferric iron was adjusted to 5:2 (A), 5:1 (B) and 10:1 (C); other preparation conditions and methods were the same, and the potassium ferrate solid product obtained after drying was placed in a brown bottle, marked and sealed for storage. A certain volume of sample was taken from the three potassium ferrate solid products, dissolved in a 10 mL vial, and the purity of the obtained solid potassium ferrate was calculated by direct spectrophotometry and ABTS method, as shown in the following table:

[0067]

[0068] It can be seen from the above table that among the three dosage ratios, the purity of potassium ferrate solid is the highest at the dosage ratio of 10:1, and the purity of potassium ferrate solid can reach more than 80% at the dosage ratio of 5:1. Scheme A is used as the control group, and the purity of potassium ferrate solid is less than 80% at the dosage ratio of 5:2.

[0069] Example 2

[0070] This example is used to verify the effect of mixing different alkali solutions with sodium hypochlorite on the purity of potassium ferrate solid.

[0071] The same preparation method and preparation conditions were used to prepare potassium ferrate solid products using sodium hydroxide (D) and potassium hydroxide (E) as alkali solutions. The results are shown in the following table:

[0072]

[0073] As can be seen from the above table, the potassium ferrate solid products prepared by the two different alkali solutions have high purity, and the purity of potassium hydroxide as the alkali solution is higher than that of sodium hydroxide as the alkali solution. In addition, when sodium hydroxide is used as the alkali solution, the preparation process requires a recrystallization process, which consumes a lot of resources and the process is also more complicated. When potassium hydroxide is used as the alkali solution, the recrystallization process can be omitted.

[0074] Example 3

[0075] This example is used to verify the influence of different pre-rinsing organic solvents on the purity of potassium ferrate solid and the cost comparison.

[0076] Using the same preparation method, preparation conditions and subsequent organic solvent rinsing conditions, ethanol (F) and methanol (G) were used as the organic solvents for rinsing the crude potassium ferrate product in the early stage, and the purity of the prepared potassium ferrate product was determined. The results are as follows:

[0077]

[0078] As can be seen from the above table, when ethanol is used as the preliminary cleaning agent, the purity of the potassium ferrate solid product prepared is slightly higher than that of the potassium ferrate when methanol is used as the preliminary cleaning agent. Subsequently, the same preparation method and preparation conditions were adopted, ethanol was used as the preliminary cleaning agent, and the amount of organic solvent for the subsequent rinsing was halved (H). The results showed that when ethanol was used as the preliminary cleaning agent, halving the amount of organic solvent in the subsequent stage had little effect on the purity of the prepared potassium ferrate product, and ethanol was non-toxic, which could improve the safety and economic benefits of the preparation process to a certain extent.

[0079] Example 4

[0080] This example is used to verify the stability of the potassium ferrate product prepared in Example 1.

[0081] like Figure 3 As shown, the potassium ferrate solid product prepared in Example 1 and the commercially available potassium ferrate solid product were subjected to spectral analysis, and both had the same characteristic absorption peak.

[0082] Commercially available potassium ferrate solid agent A, commercially available potassium ferrate solid agent B, newly prepared homemade potassium ferrate (Example 1) and homemade potassium ferrate (Example 1) stored for 30 days were selected for phenol removal experiments. In the experiment, the same volume of potassium ferrate solid was dissolved in a 10 mL vial, and then 100 μmol / L of potassium ferrate was taken to remove 5 μmol / L of phenol. The removal effect is shown in FIG. Figure 4 shown.

[0083] Among them, the commercially available potassium ferrate A is the potassium ferrate sold by McLean Reagent Company, and the commercially available potassium ferrate B is the potassium ferrate sold by Aladdin Reagent Company. It can be found that the homemade potassium ferrate has higher purity and better stability than the commercially available potassium ferrate, and the oxidation ability of the homemade potassium ferrate does not change significantly after long-term storage, and can be stored for a long time. Therefore, the potassium ferrate prepared by this method has higher purity and better stability.

[0084] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0085] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A simple and efficient integrated potassium ferrate preparation device, characterized in that: include: A mixing box (11), wherein the mixing box (11) is capable of mixing the sodium hypochlorite solution and the potassium hydroxide solution to form an alkaline sodium hypochlorite solution; A preparation box (10), wherein the preparation box (10) is capable of mixing an alkaline sodium hypochlorite solution with a ferric iron solid powder to form a potassium ferrate solution; A centrifugal filter device (14), wherein the centrifugal filter device (14) is capable of centrifugally filtering a potassium ferrate solution to form a filtrate and a potassium ferrate solid raw material, wherein the centrifugal filter device (14) has a liquid discharge pipe (15) and a solid discharge pipe (22), wherein the filtrate is discharged through the liquid discharge pipe (15), and the potassium ferrate solid raw material is discharged into a solid collector (23) through the solid discharge pipe (22), wherein the solid collector (23) is filled with an alkali solution, and wherein the potassium ferrate solid raw material is mixed with the alkali solution in the solid collector (23) and allowed to stand to form a potassium ferrate solid coarse material; A purification device (18), the purification device (18) being connected to the centrifugal filtering device (14), the purification device (18) comprising a circulation pump (13), the circulation pump (13) being capable of pumping potassium ferrate solid coarse material into the purification device (18), and the purification device (18) being capable of rinsing the potassium ferrate solid coarse material to form potassium ferrate solid fine material; A drying device (19), wherein the drying device (19) is capable of drying the potassium ferrate solid fine material to form a potassium ferrate solid product; The centrifugal filter device (14) comprises: a centrifugal chamber (26), the centrifugal chamber (26) being in communication with the preparation box (10), and a centrifugal shaft (24) being arranged at the bottom center of the centrifugal chamber (26); one end of the solid discharge pipe (22) being in communication with the bottom of the centrifugal chamber (26), the communication point being spaced apart from the centrifugal shaft (24), and the other end being in communication with the solid collector (23); an outer cavity (27), the outer cavity (27) being arranged outside the centrifugal cavity (26), the centrifugal cavity (26) being provided with through holes penetrating the inner and outer surfaces, a filter cloth (21) being provided on the inner side wall of the centrifugal cavity (26) and covering the through holes, one end of the drainage pipe (15) being in communication with the outer cavity (27), the communication point being close to the top of the centrifugal cavity (26), and the other end extending outward; A scraper (25), the scraper (25) being driven by a pneumatic device (20), the scraper (25) being provided with an infrared sensor, the infrared sensor being capable of detecting the thickness of the potassium ferrate solid coarse material on the inner side wall and / or the bottom of the centrifugal chamber (26); when the thickness of the potassium ferrate solid coarse material on the inner side wall and / or the bottom of the centrifugal chamber (26) reaches a preset value, the scraper (25) is capable of scraping the potassium ferrate solid coarse material on the inner side wall and the bottom of the centrifugal chamber (26) into the solid collector (23).

2. A simple and efficient integrated potassium ferrate preparation device according to claim 1, characterized in that: The mixing box (11) is connected to the sodium hypochlorite solution storage box (6) and the potassium hydroxide solution storage box respectively; the potassium hydroxide solution storage box is located inside the mixing box (11); the potassium hydroxide solution storage box and the sodium hypochlorite solution storage box (6) are both connected to the mixing box (11) via a liquid inlet pipe; a peristaltic pump is provided on the liquid inlet pipe.

3. A simple and efficient integrated potassium ferrate preparation device according to claim 1, characterized in that: The preparation box (10) is connected to the mixing box (11) and the ferric iron storage box (2) respectively. The bottom surface of the mixing box (11) and the connection point between the mixing box (11) and the preparation box (10) are provided with a filter layer, and the filter layer is made of glass fiber and has a thickness of 8-20 mm.

4. A simple and efficient integrated potassium ferrate preparation device according to claim 3, characterized in that: The ferric iron storage tank (2) has a grinding device (3), and the grinding device (3) is capable of grinding ferric iron solid to form ferric iron solid powder.

5. A simple and efficient integrated potassium ferrate preparation device according to claim 1, characterized in that: A magnetic stirrer and a first ultrasonic device are arranged in the preparation box (10), and a temperature control device is arranged on the outer surface of the preparation box (10), wherein the temperature control device can maintain the internal temperature of the preparation box (10) at 5-10°C.

6. A simple and efficient integrated potassium ferrate preparation device according to claim 1, characterized in that: The purification device (18) comprises: a purification chamber, the purification chamber being in communication with the centrifugal chamber (26) via a connecting pipe, the circulating pump (13) being arranged on the connecting pipe, and a second ultrasonic device being arranged in the purification chamber; an organic solvent storage box (17), the organic solvent storage box (17) being in communication with the purification chamber, and the organic solvent storage box (17) being filled with an organic solvent; The tray has multiple layers and is evenly spaced from top to bottom. The potassium ferrate solid coarse material is sucked into the tray by a circulation pump (13) and a connecting pipe. The organic solvent storage tank (17) can transport the organic solvent to the tray and rinse the potassium ferrate solid coarse material.

7. A simple and efficient integrated preparation method of potassium ferrate, characterized in that: The simple and efficient integrated potassium ferrate preparation device according to any one of claims 1 to 6 comprises the following steps: S1: pumping a sodium hypochlorite solution and a potassium hydroxide solution into a mixing box (11), and mixing them in the mixing box (11) to form an alkaline sodium hypochlorite solution; S2: feeding the ferric iron fixed powder and the alkaline sodium hypochlorite solution into a preparation box (10), and mixing them in the preparation box (10) by a magnetic stirrer and a first ultrasonic device to form a potassium ferrate solution; S3: the potassium ferrate solution enters the centrifugal filter device (14), is separated by the centrifugal shaft (24) to form a filtrate and a potassium ferrate solid raw material, the filtrate is discharged through the discharge pipe (15), and the potassium ferrate solid raw material is discharged into the solid collector (23) through the solid discharge pipe (22), and the solid collector (23) is filled with alkali solution. The potassium ferrate solid raw material is mixed with the alkali solution in the solid collector (23) and allowed to stand to form a potassium ferrate solid coarse material; S4: The potassium ferrate solid crude material is sucked from the solid collector (23) into the purification chamber through the circulation pump (13) and the connecting pipe, and an organic solvent is introduced into the purification chamber to rinse the potassium ferrate solid crude material with the organic solvent and the second ultrasonic device until the potassium ferrate solid crude material at the bottom layer of the purification chamber turns purple-black and has no other colors, thereby forming potassium ferrate solid fine material; S5: The rinsed potassium ferrate solid fine material is placed in a drying device (19) and dried to obtain a potassium ferrate solid product.

8. A simple and efficient integrated method for preparing potassium ferrate according to claim 7, characterized in that: The sodium hypochlorite solution is a sodium hypochlorite solution with an effective chlorine content of 8%-20%. The stoichiometric ratio of the sodium hypochlorite to the trivalent iron fed into the preparation box (10) is 5-10. The trivalent iron fixed powder is fed into the preparation box (10) in a multiple-dose manner.

9. A simple and efficient integrated method for preparing potassium ferrate according to claim 7, characterized in that: The organic solvents used are ethanol, n-hexane, n-pentane, methanol and ether; during rinsing, the potassium ferrate solid crude material is firstly rinsed with ethanol and a second ultrasonic device, and then rinsed with n-hexane, n-pentane, methanol, ether and a second ultrasonic device.

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