A method for purifying high-purity potassium ferrate

Abstract

The present invention discloses a method for purifying high-purity potassium ferrate, comprising the following steps: S1, adding a dilute KOH solution with a concentration of 2 to 6 mol / L to a crude potassium ferrate product to fully dissolve the crude potassium ferrate product, and collecting the filtrate for later use; S2, recrystallization: placing the filtrate in a constant temperature water bath, slowly adding a concentrated KOH solution with a concentration of 15 to 20 mol / L during stirring until potassium ferrate solid precipitates from the solution, standing for 15 to 90 minutes, and removing the filtrate to obtain potassium ferrate crystals; S3, washing: washing the potassium ferrate crystals multiple times; S4, drying: placing the washed potassium ferrate on a watch glass and drying it in a vacuum drying oven to obtain high-purity potassium ferrate. The present invention optimizes the purification process and refines the test parameters of the dissolution process, recrystallization process, rinsing process, and drying process to achieve a one-time purification of more than 90%, thereby improving the purification efficiency and reducing the purification cost.

Description

Technical Field

[0001] The present invention relates to the technical field of chemical production, and in particular to a method for purifying high-purity potassium ferrate. Background Art

[0002] Potassium ferrate is a green, multifunctional, strong oxidant widely used in water treatment. Investigations and testing of commercially available potassium ferrate products revealed that their purity is very low, reaching only around 20%. This not only affects the stability of potassium ferrate but also its effectiveness. Therefore, there is a need to further improve the purity of commercially available potassium ferrate products.

[0003] Since the purification process involves issues such as operating techniques and operating proficiency, slight operating differences may lead to significant changes in the potassium ferrate content in the product. Therefore, optimizing the purification process has an important impact on ensuring the purity of potassium ferrate in the product. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention provides a method for purifying high-purity potassium ferrate.

[0005] The technical solution of the present invention is: a method for purifying high-purity potassium ferrate, comprising the following steps:

[0006] S1. Dissolving the raw materials: Add a dilute KOH solution with a concentration of 2-6 mol / L to the crude potassium ferrate product to fully dissolve the crude potassium ferrate product; then use a funnel to filter to remove impurities and collect the filtrate for later use;

[0007] S2. Recrystallization: Place the filtrate in a thermostatic water bath set at 0-30°C, continue stirring, and slowly add a 15-20 mol / L concentrated KOH solution during stirring until potassium ferrate solid precipitates from the solution. Let the solution stand at the set temperature of the thermostatic water bath for 15-90 minutes; then remove the filtrate using a funnel to obtain potassium ferrate crystals.

[0008] S3, washing: washing the potassium ferrate crystals multiple times to obtain washed potassium ferrate;

[0009] S4. Drying: Place the washed potassium ferrate on a watch glass, and place it in a vacuum drying oven for drying to obtain high-purity potassium ferrate.

[0010] Furthermore, the method of multiple washing is:

[0011] 1) Primary washing: using a non-polar solvent to azeotropically remove water from the potassium ferrate crystals; wherein the non-polar solvent is any one of cyclohexane and n-hexane;

[0012] 2) Secondary washing: using a polar non-aqueous solvent to remove residual inorganic salts in the potassium ferrate crystals; wherein the polar non-aqueous solvent is any one of anhydrous ethanol and anhydrous methanol;

[0013] 3) Three washings: using a volatile non-polar solvent to wash and remove the solvent introduced in steps 1) and 2); wherein the volatile non-polar solvent is any one of petroleum ether, cyclohexane, and n-hexane.

[0014] Description: The recrystallized product is treated by the above-mentioned multiple washings. First, a non-polar solvent (cyclohexane, n-hexane) is used to remove moisture from the product. Then, a polar non-aqueous solvent (anhydrous ethanol, anhydrous methanol) is used to remove residual inorganic salts in the product. Finally, a volatile non-polar solvent (petroleum ether, cyclohexane, n-hexane) is used to remove the organic solvent introduced in the rinsing step. The principle of the entire rinsing process is clear, more targeted than rinsing with only isopropanol, and has higher purification efficiency. In addition, the present invention provides multiple options in the process of multiple washings, improves the rinsing efficiency, and uses volatile solvents such as petroleum ether, cyclohexane, and n-hexane instead of chemical ether, thereby reducing the harmfulness of purification.

[0015] Furthermore, the funnels in step S1 and step S2 are both G3 sand core funnels.

[0016] Note: Since potassium ferrate is highly oxidizing, and the main component of filter paper is cellulose, which is reducing, the filter paper will be corroded by potassium ferrate; therefore, the use of a G3 sand core funnel can well meet the use requirements of the purification method of the present invention.

[0017] Furthermore, the potassium ferrate washed in step S4 is dried at a temperature of 45-95° C. for 1 hour.

[0018] Note: Experiments have found that the purity of potassium ferrate varies when dried at different drying temperatures. The above drying temperature range can keep the purity of potassium ferrate crystals at a higher level, which is conducive to obtaining high-purity potassium ferrate.

[0019] Furthermore, the non-polar solvent is cyclohexane, the polar non-aqueous solvent is anhydrous methanol, and the volatile non-polar solvent is petroleum ether.

[0020] Note: Experiments have found that the effect is better when cyclohexane is used as a non-polar solvent. When n-hexane is used for treatment, the process is slower and it is difficult to completely remove the water contained in potassium ferrate. The effect is better when anhydrous methanol is used as a polar non-aqueous solvent. By using petroleum ether, the use of ether can be avoided. Because ether is volatile and has a strong odor, it is more dangerous and has great hazards in actual mass production.

[0021] Furthermore, the addition ratio of the crude potassium ferrate product and the dilute KOH solution is: 25 mL of the dilute KOH solution is added to every 5.00 g of the crude potassium ferrate product.

[0022] Note: The above ratio can effectively dissolve the corresponding industrial-grade crude potassium ferrate product, avoiding the problem of increased costs caused by excessive dilute KOH solution.

[0023] Furthermore, the amount of the non-polar solvent, polar non-aqueous solvent or volatile non-polar solvent added is: 20-60 mL of the non-polar solvent, polar non-aqueous solvent or volatile non-polar solvent is used for every 5.00 g of crude potassium ferrate product.

[0024] Note: The above ratio can effectively wash potassium ferrate and avoid the problem of high costs caused by excessive use of non-polar solvents, polar non-aqueous solvents or volatile non-polar solvents.

[0025] Furthermore, in the one-time washing, an intermittent mixing device is used for one-time washing treatment, and the non-polar solvent is sprayed multiple times and azeotropically treated with the potassium ferrate crystals by intermittent mixing, specifically:

[0026] 1) A single dose of the non-polar solvent is 1 / 6 to 1 / 4 of the total amount of the non-polar solvent added, and the spraying temperature of the non-polar solvent is 15 to 20° C. The single dose of the non-polar solvent is sprayed and mixed with the potassium ferrate crystals;

[0027] 2) After the non-polar solvent and potassium ferrate crystals are mixed once, the mixture is allowed to stand for 1 to 3 minutes, and then the potassium ferrate crystals are dried at 75° C. for 20 to 50 seconds;

[0028] 3) Then repeat the above steps 1)-2) to repeatedly spray and mix the potassium ferrate crystals with a single dose of non-polar solvent, let it stand, and dry it to complete one washing process.

[0029] Note: In actual operation, it is found that the precipitate obtained after potassium ferrate crystallization is a purple-black, fine, and sticky mud-like substance, which is easy to form agglomerates and it is difficult to completely wash out the water contained therein. The above-mentioned one-time washing treatment method can effectively improve the effect of removing water after potassium ferrate crystallization in an intermittent manner, and the intermittent change of temperature difference can also effectively reduce the problem of the purple-black, dense, and sticky mud-like substance forming agglomerates, thereby completely washing out the water contained in the potassium ferrate crystallization.

[0030] Furthermore, the intermediate mixing equipment includes an intermediate mixing combination chamber for adding a non-polar solvent and azeotropically co-existing the potassium ferrate crystals with the non-polar solvent, a carrier plate assembly for placing the potassium ferrate crystals, and a support frame;

[0031] The intermediate mixing combination warehouse includes a drying warehouse and a liquid adding warehouse arranged in sequence from top to bottom, and a detachable docking connection ring is provided between the drying warehouse and the liquid adding warehouse; a support rod is provided on each side of the liquid adding warehouse in the vertical direction, and the lower end of the support rod is fixedly connected to the support frame; the support frame is provided with a lifting motor for controlling the up and down movement of the intermediate mixing combination warehouse, and the output shaft of the lifting motor is detachably connected to the bottom surface of the liquid adding warehouse;

[0032] The carrier plate assembly is arranged inside the intermediate mixing combination bin, and the carrier plate assembly includes a carrier plate and a plurality of lifting members. Two connecting rods are symmetrically provided on the side wall of the carrier plate in the horizontal direction. The connecting rods pass through the intermediate mixing combination bin and are fixedly connected to the support rods. The side walls of the drying bin, the connecting ring, and the liquid adding bin are provided with slide grooves that are interconnected and used for the connecting rods to slide up and down in the vertical direction.

[0033] The lifting member is arranged in an embedding groove provided on the bottom surface of the carrier plate, and an elastic membrane connected to the bottom surface of the carrier plate is provided around the lifting member, the lifting member includes an airbag column, an extension piece and a connecting tube, one end of the extension piece is fixedly connected to the upper part of the side wall of the airbag column, and the other end of the extension piece is provided with a spring connected to the embedding groove, one end of the connecting tube is fixedly connected to the lower part of the side wall of the airbag column, and the other end of the connecting tube extends into an annular cavity provided in the side wall of the carrier plate, an arc-shaped airbag sheet corresponding to the lifting member is provided in the annular cavity, a trigger ring rotatably sealed and connected to the annular cavity is provided above the arc-shaped airbag sheet, a pressing sheet for squeezing the arc-shaped airbag sheet by rotation is provided on the lower end surface of the trigger ring, a plurality of hydraulic inclined grooves are circumferentially provided on the upper end surface of the trigger ring, and a plurality of pneumatic inclined holes are circumferentially provided on the side wall of the trigger ring below the hydraulic inclined groove;

[0034] Two docking assemblies are symmetrically provided on the upper end surface of the side wall of the carrier plate, and the docking assembly includes a liquid inlet docking port fixed to the upper end surface of the side wall of the carrier plate, and an air inlet docking port provided on one side of the liquid inlet docking port and fixed to the side wall of the carrier plate. One end of the liquid inlet docking port is connected to the hydraulic chute, and the other end of the liquid inlet docking port is provided with a liquid inlet. One end of the air inlet docking port is connected to the pneumatic inclined hole, and the other end of the air inlet docking port is provided with an air inlet. The inner side wall of the carrier plate is provided with a plurality of liquid outlet pipes for connecting to the hydraulic chute and a plurality of air outlet pipes for connecting to the pneumatic inclined hole, and the liquid outlet pipes and the air outlet pipes are both arranged to be inclined downward at 15°.

[0035] The top surface of the drying chamber is provided with a heating plate and an air intake fan. Two air intake fans are provided and correspond one to one with the air intake docking ports. The air outlet duct of the air intake fan passes through the drying chamber and is provided with an interface docking with the air intake port. A condensation box is provided on the outer side of the side wall of the drying chamber. An air extraction pump is provided on each side of the condensation box. The air extraction pump is connected to the upper part of the drying chamber through a pipeline.

[0036] Two liquid supply boxes are provided on the inner side wall of the liquid filling bin, and the liquid supply boxes correspond to the liquid inlet docking ports one by one. The liquid supply box near the liquid inlet docking port is provided with a sink and a baffle slidably connected to the sink in the vertical direction, and the lower end of the baffle is provided with a trigger plate for cooperating with the bottom surface of the carrier plate, and the side wall of the liquid supply box is provided with a guide groove for making the trigger plate move up and down, and the lower end of the baffle is provided with a spring for connecting with the bottom surface of the sink, and a connecting pipe is provided on the upper part of the liquid supply box in the horizontal direction, and the connecting pipe is slidably and sealedly connected to the pipe groove of the liquid supply box, and one end of the connecting pipe is provided with a spring for connecting to the inner end surface of the pipe groove, and the upper end surface of the connecting pipe is provided with a second liquid port that is connected to the first liquid port provided at the front end of the top surface of the pipe groove by sliding the connecting pipe, and the first liquid port extends into the bottom of the liquid storage area of ​​the liquid supply box through a bent pipe, and the other end of the connecting pipe and the liquid inlet are provided with a magnetic ring, and the bottom surface of the connecting pipe is provided with an inclined block for cooperating with the baffle to move;

[0037] An inflatable airbag is provided at the upper and lower parts of the chute, one end of the inflatable airbag is connected to the chute, and the other end of the inflatable airbag is connected to the connecting rod. The inflatable airbag is connected to the pressurizing port provided on the liquid supply box through a hose, and the pressurizing port is connected to the liquid storage area of ​​the liquid supply box.

[0038] Description: Through the above-mentioned structure of the mixed equipment for one-time washing, the carrier plate assembly can be switched between the drying chamber and the liquid filling chamber by the reciprocating up and down motion of the lifting motor. In addition, the drying chamber and the liquid filling chamber are also equipped with device components that automatically cooperate with the carrier plate assembly to perform heating and liquid replenishment. Automatic switching and docking are achieved through mechanical components, and this function can be achieved without the need for additional electronic control components.

[0039] At the same time, through the carrier plate assembly provided, the device can use lifting parts, trigger rings and other components to intermittently drive the lifting parts for lifting when replenishing cyclohexane or filling with gas to accelerate the circulation, thereby solving the problem that the precipitate obtained after potassium ferrate crystallization is a purple-black fine and viscous muddy substance that is easy to form agglomerates. In addition, this setting can improve the dehydration efficiency of potassium ferrate, thereby quickly and thoroughly removing the water contained in the potassium ferrate crystallization.

[0040] The beneficial effects of the present invention are:

[0041] (1) The present invention optimizes the purification process and refines the test parameters of the dissolution process, recrystallization process, washing process and drying process, so that the purification rate reaches more than 90% in one time, thereby improving the purification efficiency and reducing the purification cost.

[0042] (2) The present invention further reduces the hazards of actual production by using petroleum ether or cyclohexane, n-hexane, etc. as volatile non-polar solvents to replace anhydrous ether.

[0043] (3) The present invention optimizes a single wash and utilizes an intermittent and temperature-difference method to effectively improve the effect of removing moisture after potassium ferrate crystallization, thereby thoroughly washing away the moisture contained in potassium ferrate crystallization.

[0044] (4) The present invention can simplify the operational complexity of a single washing method by providing an intermediate mixing device for the single washing method. The drying chamber and the liquid adding chamber are also provided with device components that automatically cooperate with the carrier assembly to perform heating and liquid replenishment. Automatic switching and docking are achieved through mechanical components, without the need for additional electronic control components. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 This is a comparison chart of the effect of KOH concentration on the dissolution process of the purification method of the present invention;

[0046] Figure 2 This is a comparison chart of the effect of recrystallization temperature on the purification method of the present invention;

[0047] Figure 3 This is a comparison chart of the effect of KOH concentration on the purification method of the present invention;

[0048] Figure 4 This is a comparison chart showing the effect of recrystallization time on the purification method of the present invention;

[0049] Figure 5 This is a comparison chart of the effects of drying temperature on the purification method of the present invention;

[0050] Figure 6 This is a comparison chart of the screening of dehydration solvents in the purification method of the present invention;

[0051] Figure 7 This is a comparison chart of screening desalting solvents for the purification method of the present invention;

[0052] Figure 8 It is a comparison chart of screening of volatile solvents in the purification method of the present invention;

[0053] Figure 9 1 is the UV-visible absorption spectrum of potassium ferrate before and after purification of the present invention;

[0054] Figure 10 1 is an XRD diagram of potassium ferrate before and after purification of potassium ferrate according to the present invention;

[0055] Figure 11 This is a SEM image of potassium ferrate before and after purification of the present invention, magnified 1000 times;

[0056] Figure 12 It is a schematic diagram of the overall structure of the intermediate mixing equipment of the present invention;

[0057] Figure 13 This is a schematic diagram of the drying chamber structure of the intermediate mixing equipment of the present invention;

[0058] Figure 14 This is a schematic diagram of the liquid adding bin structure of the intermediate mixing equipment of the present invention;

[0059] Figure 15 This is a schematic diagram of the assembly structure of the carrier plate assembly and the support frame of the intermediate mixing equipment of the present invention;

[0060] Figure 16 is a partial cross-sectional schematic diagram of a carrier plate of the carrier plate assembly of the present invention;

[0061] Figure 17 Schematic diagram of the trigger ring structure of the carrier assembly of the present invention;

[0062] Figure 18 It is a schematic structural diagram of the lifting member of the carrier assembly of the present invention;

[0063] Figure 19 This is a schematic diagram of the external structure of the liquid supply box of the liquid adding bin of the present invention;

[0064] Figure 20 It is a schematic diagram of the internal structure of the liquid supply box of the liquid adding bin of the present invention;

[0065] Among them, 1-support frame, 11-support rod, 12-lifting motor, 2-drying chamber, 21-heating plate, 22-intake fan, 23-condensation box, 24-vacuum pump, 3-liquid adding chamber, 31-liquid supply tank, 32-sink, 33-baffle, 34-trigger plate, 35-pipe groove, 36-connecting pipe, 37-pressurization port, 4-carrying plate, 41-connecting rod, 42-arc-shaped airbag piece, 43-liquid inlet interface, 44-air inlet interface, 45-liquid outlet pipe, 46-air outlet pipe, 5-lifting piece, 51-airbag column, 52-extension piece, 53-connecting pipe, 6-trigger ring, 61-pressing piece, 62-hydraulic inclined groove, 63-pneumatic inclined hole, 7-inflatable airbag, 8-connecting ring. DETAILED DESCRIPTION

[0066] The present invention will be further described in detail below in conjunction with specific implementation methods to better demonstrate the advantages of the present invention.

[0067] In certain embodiments, a method for purifying high-purity potassium ferrate comprises dissolving the raw material in a dilute KOH solution having a concentration of 2 to 6 mol / L; then adding a concentrated KOH solution having a concentration of 15 to 20 mol / L until solid potassium ferrate precipitates from the solution; and then performing multiple washing and drying steps to obtain high-purity potassium ferrate with a purity greater than 90%. By optimizing the purification process and refining the experimental parameters of the dissolution, recrystallization, rinsing, and drying processes, a single-stage purification of greater than 90% can be achieved, thereby improving purification efficiency and reducing purification costs.

[0068] In certain embodiments, the multiple washing method comprises: sequentially using a non-polar solvent to azeotropically remove moisture from the potassium ferrate crystals, using a polar non-aqueous solvent to wash and remove residual inorganic salts from the potassium ferrate crystals, and using a volatile non-polar solvent to wash and remove the solvent introduced by the first two washes; wherein the non-polar solvent is any one of cyclohexane and n-hexane; the polar non-aqueous solvent is any one of anhydrous ethanol and anhydrous methanol; and the volatile non-polar solvent is any one of petroleum ether, cyclohexane, and n-hexane. The principle of this multiple washing process is clear, more targeted than rinsing with only isopropyl alcohol, and has higher purification efficiency. In addition, the present invention provides multiple options during the multiple washing process to improve rinsing efficiency, while using volatile solvents such as petroleum ether, cyclohexane, and n-hexane instead of chemical ether, thereby reducing the harmfulness of purification.

[0069] In certain embodiments, in the single washing, the non-polar solvent is sprayed multiple times with the potassium ferrate crystals in an intermittent mixing manner for azeotropic treatment, the single dose of the non-polar solvent is 1 / 6 to 1 / 4 of the total amount of the non-polar solvent added, and the spraying temperature of the non-polar solvent is 15 to 20°C. The single dose of the non-polar solvent is sprayed and mixed with the potassium ferrate crystals; after the single mixing of the non-polar solvent and the potassium ferrate crystals, the mixture is allowed to stand for 1 to 3 minutes, and then the potassium ferrate crystals are dried for 20 to 50 seconds; then the above steps are repeated to spray, mix, stand, and dry the potassium ferrate crystals with a single dose of the non-polar solvent, thereby completing the single washing process. This single washing can effectively improve the effect of removing moisture from the potassium ferrate crystals by an intermittent manner, and can also effectively reduce the problem of the purple-black, dense, and viscous muddy substance from forming lumps by intermittent changes in temperature, thereby thoroughly washing the moisture contained in the potassium ferrate crystals.

[0070] In certain embodiments, a single washing process is performed using a mixing device comprising a mixing chamber for adding a non-polar solvent and azeotroping the potassium ferrate crystals with the non-polar solvent, a tray assembly for placing the potassium ferrate crystals, and a support frame. This mixing device can improve the dehydration efficiency of the potassium ferrate, thereby quickly and completely removing the moisture contained in the potassium ferrate crystals.

[0071] In order to better illustrate the technical effects of the present invention, the present researcher further elaborates on the relevant experimental contents during the research process as follows, so that those skilled in the art can fully understand the technical concept of the present invention.

[0072] Example 1

[0073] A method for purifying high-purity potassium ferrate comprises the following steps:

[0074] S1. Dissolving the raw materials: Add 25 mL of a 3 mol / L dilute KOH solution to 5.00 g of crude potassium ferrate to fully dissolve the crude potassium ferrate; then use a G3 sand core funnel to filter out impurities and collect the filtrate for later use;

[0075] S2. Recrystallization: Place the filtrate in a thermostatic water bath set at 0°C, continue stirring, and slowly add a 15-20 mol / L concentrated KOH solution during stirring until potassium ferrate solid precipitates from the solution. Let the solution stand at the set temperature of the thermostatic water bath for 30 minutes; then use a G3 sand core funnel to remove the filtrate to obtain potassium ferrate crystals.

[0076] S3, washing: washing the potassium ferrate crystals multiple times to obtain washed potassium ferrate; wherein the multiple washing methods are:

[0077] 1) One wash: using 60 mL of a non-polar solvent to azeotropically remove water from the potassium ferrate crystals; wherein the non-polar solvent is cyclohexane;

[0078] 2) Secondary washing: using 60 mL of a polar non-aqueous solvent to remove residual inorganic salts in the potassium ferrate crystals; wherein the polar non-aqueous solvent is anhydrous methanol;

[0079] 3) Three washes: Use 60 mL of volatile non-polar solvent to wash and remove the solvent introduced in steps 1) and 2); wherein the volatile non-polar solvent is petroleum ether

[0080] S4. Drying: Place the washed potassium ferrate on a watch glass, place in a vacuum drying oven and dry at 65° C. for 1 hour to obtain high-purity potassium ferrate.

[0081] Example 2

[0082] The difference from Example 1 is that 25 mL of a dilute KOH solution with a concentration of 2 mol / L is added to 5.00 g of crude potassium ferrate product.

[0083] Example 3

[0084] The difference from Example 1 is that 25 mL of a 6 mol / L dilute KOH solution was added to 5.00 g of crude potassium ferrate product.

[0085] Example 4

[0086] The difference from Example 1 is that the filtrate is placed in a constant temperature water bath and the temperature is set at 10°C.

[0087] Example 5

[0088] The difference from Example 1 is that the filtrate is placed in a constant temperature water bath and the temperature is set at 30°C.

[0089] Example 6

[0090] The difference from Example 1 is that the filtrate is placed in a constant temperature water bath, and a concentrated KOH solution with a concentration of 15 mol / L is slowly added during stirring until potassium ferrate solid precipitates in the solution.

[0091] Example 7

[0092] The difference from Example 1 is that the filtrate is placed in a constant temperature water bath, and a concentrated KOH solution with a concentration of 20 mol / L is slowly added during stirring until potassium ferrate solid precipitates in the solution.

[0093] Example 8

[0094] The difference from Example 1 is that the mixture is left to stand at the set temperature of the constant temperature water bath for 15 minutes.

[0095] Example 9

[0096] The difference from Example 1 is that the mixture is left to stand at the set temperature of the constant temperature water bath for 90 minutes.

[0097] Example 10

[0098] The difference from Example 1 is that the drying is performed at 45° C. for 1 hour.

[0099] Example 11

[0100] The difference from Example 1 is that the drying is performed at 95° C. for 1 hour.

[0101] Example 12

[0102] The difference from Example 1 is that the non-polar solvent is 40 mL of cyclohexane; the polar non-aqueous solvent is 40 mL of anhydrous methanol; and the volatile non-polar solvent is 40 mL of petroleum ether.

[0103] Example 13

[0104] The difference from Example 1 is that the non-polar solvent is 20 mL of cyclohexane; the polar non-aqueous solvent is 20 mL of anhydrous methanol; and the volatile non-polar solvent is 20 mL of petroleum ether.

[0105] The high-purity potassium ferrate obtained by the purification method of Example 1-13 was tested and analyzed as follows:

[0106] 1. Effect of dissolution process on the purification of potassium ferrate

[0107] This experiment investigated the effect of dissolving potassium ferrate in 2-6 mol / L KOH solution on the recrystallization effect. Figure 1 As shown, it was found that when the concentration of the dilute KOH solution was in the range of 2 to 6 mol / L, as the concentration of the dilute KOH solution increased, the purity of the obtained potassium ferrate crystals increased, reaching a maximum value when the concentration of the dilute KOH solution was 3 mol / L, and then continued to increase the concentration of the dilute KOH solution, the purity of the potassium ferrate crystals decreased.

[0108] The recovery rate of potassium ferrate crystals gradually increases with the increase of KOH concentration. Considering the purity and recovery rate, a KOH solution with a concentration of 3-4 mol / L can be selected to dissolve the crude potassium ferrate product. After a single recrystallization, the purity of the solid potassium ferrate can reach over 80%.

[0109] Therefore, if Figure 1 As shown, compared with Examples 2 and 3, Example 1 is relatively optimal in purification effect, and Example 3 is relatively optimal in recovery rate. At the same time, a comprehensive selection can also be made according to actual production needs, for example: 4 mol / L dilute KOH solution.

[0110] 2. Influence of recrystallization temperature

[0111] This experiment investigated the effects of different temperatures between 0 and 60 °C on the recrystallization effect. Figure 2 As shown in the figure, with the increase of recrystallization temperature, the purity and recovery rate of potassium ferrate crystals gradually decreased. Overall, recrystallization at low temperature is relatively better for its purity and recovery rate.

[0112] Therefore, if Figure 2 As shown, compared with Examples 4 and 5, Example 1 is relatively optimal in terms of recrystallization effect. However, in order to consider the factors of actual production conditions, overall, good purification effects are achieved in the range of 0 to 30°C, and actual settings can be made as needed in actual production.

[0113] 3. Effect of Recrystallization Process on Purification of Potassium Ferrate

[0114] This experiment investigated the effect of 15-20 mol / L KOH solution on the purity and recovery of potassium ferrate during recrystallization. Figure 3 As shown in the figure, when the concentration of concentrated KOH solution is in the range of 15 to 17 mol / L, as the concentration of concentrated KOH increases, the purity and recovery rate of the obtained potassium ferrate crystals increase; thereafter, as the concentration of concentrated KOH solution continues to increase, the purity and recovery rate of the potassium ferrate crystals decrease.

[0115] Therefore, if Figure 3As shown, compared with Examples 6 and 7, Example 1 is relatively optimal in terms of recrystallization effect, and the purity of solid potassium ferrate obtained by one recrystallization can reach more than 80%.

[0116] 4. Influence of recrystallization standing time

[0117] This experiment investigated the effect of 15 to 90 min crystallization time on the recrystallization effect. Figure 4 As shown, it can be seen that with the increase of recrystallization time, the purity and recovery rate of potassium ferrate crystals first increase and then decrease.

[0118] Therefore, if Figure 4 As shown, compared with Examples 8 and 9, the potassium ferrate purification process of Example 1 is better under the process conditions of Example 1.

[0119] 5. Effect of Drying Temperature on Purification of Potassium Ferrate

[0120] This experiment investigated the effect of drying temperature between 45 and 95°C on the purity of potassium ferrate crystals. Figure 5 As shown, it was found that when the drying temperature was 45-65°C, the purity of potassium ferrate crystals increased slowly with the increase of temperature; when the temperature was higher than 65°C, the purity of potassium ferrate slowly decreased with the increase of temperature.

[0121] Therefore, if Figure 5 As shown, compared with Examples 10 and 11, the drying temperature of Example 1 has the best effect on purification.

[0122] 6. Effect of dehydrating solvent (non-polar solvent)

[0123] The commonly used solvent for potassium ferrate dehydration is n-hexane, but in actual operation, it is found that the process of washing potassium ferrate crystals with n-hexane is extremely slow. The precipitate obtained after potassium ferrate crystallization is a purple-black, fine, viscous mud-like substance that easily forms lumps and is difficult to completely wash out the water contained in it. Figure 6 As shown, taking Example 12 as a reference, after using the same dosage of non-polar organic solvents such as n-hexane, cyclohexane, petroleum ether, toluene and benzene to dehydrate the potassium ferrate crystalline product, it was found that cyclohexane had the best dehydration effect per unit time.

[0124] Therefore, if Figure 6 As shown in the figure, cyclohexane is the best choice for non-polar solvents.

[0125] 7. Influence of desalting solvent (polar non-aqueous solvent)

[0126] The most commonly used desalination solvent is anhydrous ethanol. Figure 7As shown, using Example 12 as a reference, when using anhydrous methanol, anhydrous ethanol, isopropanol, acetonitrile, and acetone to rinse the product, it was found that anhydrous methanol was more efficient in removing inorganic salt ions from the product than anhydrous ethanol. In addition, the recovery rate of isopropanol was also relatively high, and all of them can be used as suitable desalination solvents.

[0127] Therefore, if Figure 7 As shown in the figure, anhydrous methanol is relatively the best choice for polar non-aqueous solvents.

[0128] 8. Influence of volatile solvents (volatile non-polar solvents)

[0129] The most commonly used flushing agent is anhydrous ether, but ether is a chemical and is very dangerous in actual production use. Figure 8 As shown, with Example 12 as a reference, by comparing the same doses of ether, petroleum ether, cyclohexane and normal hexane, it is found that petroleum ether can also obtain higher purity and recovery rate, and cyclohexane and normal hexane can also obtain relatively good results, and all can replace ether. In subsequent production, petroleum ether, cyclohexane and normal hexane can be preferentially selected for the final rinse.

[0130] Therefore, if Figure 8 As shown in the figure, petroleum ether is the best choice for the selection of volatile non-polar solvents.

[0131] 9. Effect of dosage of non-polar solvents, polar non-aqueous solvents and volatile non-polar solvents

[0132] The experiment was repeated 5 times for Examples 12, 13, and 14, and the average purification value was obtained. The results are shown in Table 1 below:

[0133] Table 1 Effect of solvent usage on purity during multiple washings

[0134] Group purity(%) Example 12 84.31 Example 13 79.72 Example 14 68.25

[0135] From the comparison in Table 1 above, it can be seen that as the dosage of the non-polar solvent, polar non-aqueous solvent, and volatile non-polar solvent gradually decreases, their purity is affected to a certain extent. By comparing the reduction in Example 12 with Example 13, and Example 13 with Example 14, it can be found that as the dosage continues to increase, the impact on its purity becomes smaller and smaller.

[0136] Therefore, as shown in Table 1, Example 1 is relatively optimal in terms of the dosage of the non-polar solvent, the polar non-aqueous solvent, and the volatile non-polar solvent.

[0137] Example 14

[0138] On the basis of Example 1, a washing treatment was performed using an intermittent mixing device, and the non-polar solvent was sprayed multiple times with the potassium ferrate crystals using an intermittent mixing method to perform an azeotropic treatment, specifically:

[0139] 1) A single dose of the non-polar solvent is 1 / 5 of the total amount of the non-polar solvent added, and the spraying temperature of the non-polar solvent is 17° C. The single dose of the non-polar solvent is sprayed and mixed with the potassium ferrate crystals;

[0140] 2) After a single mixing of the non-polar solvent and potassium ferrate crystals, the mixture was allowed to stand for 2 minutes, and then the potassium ferrate crystals were dried at 75°C for 40 seconds;

[0141] 3) Then repeat the above steps 1)-2) 4 times to spray and mix the potassium ferrate crystals with a single dose of non-polar solvent, let it stand, and dry it to complete one washing process.

[0142] Example 15

[0143] The difference from Example 14 is that the single dose of the non-polar solvent is 1 / 6 of the total amount of the non-polar solvent added.

[0144] Example 16

[0145] The difference from Example 14 is that the single dose of the non-polar solvent is 1 / 4 of the total amount of the non-polar solvent added.

[0146] Example 17

[0147] The difference from Example 14 is that the spraying temperature of the non-polar solvent is 15° C.; after standing for 2 minutes, the potassium ferrate crystals are dried at 75° C. for 20 seconds.

[0148] Example 18

[0149] The difference from Example 14 is that the spraying temperature of the non-polar solvent is 20° C.; after standing for 2 minutes, the potassium ferrate crystals are dried at 75° C. for 50 seconds.

[0150] The high-purity potassium ferrate obtained by the purification method of Examples 14-18 was tested and analyzed as follows:

[0151] 1. The crude potassium ferrate product (purity: 26.7%) was purified using Example 14 and the intermediate mixing equipment. The following is the characterization of the potassium ferrate crystals before and after purification:

[0152] 1) UV-visible absorption spectroscopy analysis

[0153] Under alkaline conditions, the potassium ferrate solution (0.8 mmol / L) before and after purification was scanned by UV-visible absorption spectrum in the range of 300-800 nm. Figure 9 As shown, the maximum absorption peaks are detected at 505-510 nm. According to the Lambert-Beer law, the purity of the crude potassium ferrate product can be increased from 26.73% to 97.28% through the purification treatment of the present application.

[0154] 2) X-ray diffraction analysis

[0155] The crystal structures of potassium ferrate before and after purification were further compared, such as Figure 10 As shown, it was found that characteristic peaks could be clearly observed after purification, which were basically consistent with the potassium ferrate standard card, and it could be determined that the purified product was potassium ferrate.

[0156] 3) Scanning electron microscopy analysis

[0157] The appearance of potassium ferrate before and after purification was analyzed by SEM. Figure 11 As shown, it can be seen that potassium ferrate crystals are rod-shaped and plate-shaped crystals of varying lengths, with a length of about 50 to 200 μm and a particle size of about 5 to 25 μm.

[0158] 2. The influence of primary washing process parameters on purity

[0159] In comparative example 1, a non-polar solvent and potassium ferrate crystals were mixed as a whole and dried at 75° C. for 200 seconds.

[0160] Comparative Example 2 was set up, based on Example 14, without standing, and the other parameters were the same as Example 15;

[0161] Using the UV-visible absorption spectroscopy analysis method, the potassium ferrate solution (0.8 mmol / L) before and after purification in each embodiment and comparative example was scanned for UV-visible absorption spectra in the range of 300 to 800 nm under alkaline conditions. The following Table 2 was obtained by calculation using the Lambert-Beer law:

[0162] Table 2 Effect of different process parameters of one-time washing on purity

[0163]

[0164]

[0165] As can be seen from the results in Table 2, Examples 14, 15, and 16 perform a single washing treatment at different single doses, which has a certain impact on the purity. Among them, the effect of Example 15 is relatively better. However, by comparing with Example 14, it can be seen that the purity difference between the two is very small. However, the power consumption of the mixing equipment of the two is compared with the power consumption of 5 and 6 reciprocating times, respectively. Therefore, the corresponding selection can be made according to actual needs;

[0166] From the results in Table 2, it can be seen that the washing treatments performed once at different temperature differences in Examples 14, 17, and 18 have a certain impact on the purity, among which the effect of Example 14 is relatively the best.

[0167] As can be seen from the results in Table 2, Example 14 and Comparative Example 1 (ie, Example 1) can significantly improve the purity of the purified potassium ferrate by optimizing the mixing equipment and the one-time washing process. Therefore, Example 14 is relatively better.

[0168] As can be seen from the results in Table 2, Example 14 and Comparative Example 2 adopted the standing and non-standing methods, respectively. Standing for 1 to 3 minutes has an impact on the purity of the purified potassium ferrate compared to not standing. Therefore, the intermittent mixing method is used for azeotropic treatment, which promotes the purification effect of potassium ferrate.

[0169] Example 19

[0170] On the basis of Example 14, Figure 12 As shown, the indirect mixing equipment includes an indirect mixing combination chamber for adding a non-polar solvent and azeotropically co-existing potassium ferrate crystals with the non-polar solvent, a carrier plate assembly for placing potassium ferrate crystals, and a support frame 1;

[0171] like Figure 12 As shown, the intermediate mixing combination warehouse includes a drying warehouse 2 and a liquid adding warehouse 3 arranged in sequence from top to bottom, and a connecting ring 8 that is detachably connected by a convex and groove is provided between the drying warehouse 2 and the liquid adding warehouse 3; a support rod 11 is provided on each side of the liquid adding warehouse 3 in the vertical direction, and the lower end of the support rod 11 is fixedly connected to the support frame 1; a lifting motor 12 for controlling the up and down movement of the intermediate mixing combination warehouse is provided on the support frame 1, and the output shaft of the lifting motor 12 is detachably connected to the bottom surface of the liquid adding warehouse 3 by a convex and groove. The lifting motor 12 is adjusted in shape according to the commercially available lifting motor to be adapted for installation in this device;

[0172] like Figure 15 As shown, the carrier plate assembly is arranged inside the intermediate mixing combination warehouse, and the carrier plate assembly includes a carrier plate 4 and a plurality of lifting members 5. Two connecting rods 41 are symmetrically provided on the side wall of the carrier plate 4 in the horizontal direction. The connecting rods 41 pass through the intermediate mixing combination warehouse and are fixedly connected to the support rods 11. The side walls of the drying warehouse 2, the connecting ring 8, and the liquid adding warehouse 3 are provided with chutes that are interconnected and used for the connecting rods 41 to slide up and down in the vertical direction.

[0173] like Figure 16 、 17As shown in Figure 18, the lifting member 5 is arranged in the embedded groove provided on the bottom surface of the carrier plate 4, and the lifting member 5 is surrounded by an elastic membrane connected to the bottom surface of the carrier plate 4. The elastic membrane is made of American DuPont high-toughness film. The lifting member 5 includes an airbag column 51, an extension piece 52 and a connecting tube 53. One end of the extension piece 52 is fixedly connected to the upper part of the side wall of the airbag column 51, and the other end of the extension piece 52 is provided with a spring connected to the embedded groove. One end of the connecting tube 53 is fixedly connected to the lower part of the side wall of the airbag column 51, and the connecting tube 53 The other end extends into the annular cavity provided in the side wall of the carrier plate 4. The annular cavity is provided with an arc-shaped airbag sheet 42 corresponding one-to-one to the lifting member 5. A trigger ring 6 is provided above the arc-shaped airbag sheet 42 and is rotatably sealed with the annular cavity. The lower end surface of the trigger ring 6 is provided with a pressing sheet 61 for squeezing the arc-shaped airbag sheet 42 by rotation. The upper end surface of the trigger ring 6 is circumferentially provided with a plurality of hydraulic inclined grooves 62, and the side wall of the trigger ring 6 below the hydraulic inclined grooves 62 is circumferentially provided with a plurality of pneumatic inclined holes 63.

[0174] like Figure 15 、 16 As shown, two docking assemblies are symmetrically provided on the upper end surface of the side wall of the carrier plate 4, and the docking assembly includes a liquid inlet docking port 43 fixed to the upper end surface of the side wall of the carrier plate 4 and an air inlet docking port 44 provided on one side of the liquid inlet docking port 43 and fixed to the side wall of the carrier plate 4. One end of the liquid inlet docking port 43 is connected to the hydraulic chute 62, and the other end of the liquid inlet docking port 43 is provided with a liquid inlet. One end of the air inlet docking port 44 is connected to the pneumatic inclined hole 63, and the other end of the air inlet docking port 44 is provided with an air inlet; a plurality of liquid outlet pipes 45 for connecting to the hydraulic chute 62 and a plurality of air outlet pipes 46 for connecting to the pneumatic inclined hole 63 are provided on the inner side of the side wall of the carrier plate 4, and the liquid outlet pipes 45 and the air outlet pipes 46 are both arranged to be inclined downward by 15°;

[0175] like Figure 13 As shown, a heating plate 21 and an air intake fan 22 are provided on the top surface of the drying chamber 2. Two air intake fans 22 are provided and correspond one to one with the air intake docking ports 44. The air outlet duct of the air intake fan 22 passes through the drying chamber 2 and is provided with an interface for docking with the air intake 44. A condensation box 23 is provided on the outer side of the side wall of the drying chamber 2. An air extraction pump 24 is provided on each side of the condensation box 23. The air extraction pump 24 is connected to the upper part of the drying chamber 2 through a pipe. The shape of the heating plate 21 is adjusted according to the commercially available heating plate to adapt to installation in this device.

[0176] like Figure 14 、 19As shown in FIG20 , two liquid supply boxes 31 are provided on the inner side of the side wall of the liquid adding bin 3. The liquid supply boxes 31 correspond to the liquid inlet interface 43 one by one. The liquid supply box 31 near the liquid inlet interface 43 is provided with a sink 32 and a baffle 33 slidably connected to the sink 32 in the vertical direction. The lower end of the baffle 33 is provided with a trigger plate 34 for cooperating with the bottom surface of the carrier 4. The side wall of the liquid supply box 31 is provided with a guide groove for moving the trigger plate 34 up and down. The lower end of the baffle 33 is provided with a spring for connecting to the inner bottom surface of the sink 32. A connecting pipe 36 is provided horizontally at the upper portion of the liquid supply tank 31. The connecting pipe 36 is slidably and sealingly connected to the pipe groove 35 of the liquid supply tank 31. A spring is provided at one end of the connecting pipe 36 for connecting to the inner end surface of the pipe groove 35. A second liquid port is provided on the upper end surface of the connecting pipe 36, which is slidably connected to the first liquid port provided at the front end of the inner top surface of the pipe groove 35. The first liquid port extends into the bottom of the liquid storage area of ​​the liquid supply tank 31 through a curved pipe. The other end of the connecting pipe 36 and the liquid inlet are both provided with magnetic rings. The bottom surface of the connecting pipe 36 is provided with an inclined block for cooperating with the baffle 33 to move.

[0177] like Figure 12 、 15 As shown, an inflatable airbag 7 is provided at the upper and lower parts of the chute, one end of the inflatable airbag 7 is connected to the chute, and the other end of the inflatable airbag 7 is connected to the connecting rod 41. The inflatable airbag 7 is connected to the pressurizing port 37 provided on the liquid supply box 31 through a hose, and the pressurizing port 37 is connected to the liquid storage area of ​​the liquid supply box 31.

[0178] The working method of the above-mentioned intermediate mixing device is as follows: cyclohexane is divided into the liquid storage areas of the two liquid supply tanks 31, and then potassium ferrate crystals are spread flat on the bottom surface of the carrier plate 4;

[0179] The lifting motor 12 is set to start and reciprocate 5 times, and stop running for 2 minutes in the middle of a single lifting stroke. The lifting time of the lifting motor 12 is 4 seconds. This time is not recorded as the rest time of the present invention, and the time taken for this single lifting is negligible.

[0180] When the lifting motor 12 drives the intermediate mixing bin to move upward, the carrier plate assembly is located in the area where the liquid adding bin 3 is located. Specifically, the carrier plate 4 presses the trigger plate 34, causing the baffle 33 to squeeze the spring and move downward along the sink 32. When the baffle 33 moves to the bottom of the sink 32, the connecting pipe 36 loses the obstruction of the baffle 33. Under the action of the spring, the connecting pipe 36 moves outward along the pipe groove 35 and is magnetically connected to the liquid inlet interface 43, so that the first liquid port and the second liquid port are connected, so that cyclohexane is injected into the carrier plate 4. By injecting cyclohexane and acting on the liquid dynamic inclined plate 6, the liquid dynamic inclined plate 36 is opened. The groove 62 is located, thereby causing the trigger ring 6 to rotate. During the rotation, cyclohexane is injected from the liquid outlet pipe 45 onto the potassium ferrate crystals. At the same time, during the rotation of the trigger ring 6, the arc-shaped airbag sheet 42 is squeezed by the pressing sheet 61, and the airbag column 51 and the extension sheet 52 are lifted upward through the lifting member 5 connected thereto, thereby lifting and loosening the potassium ferrate crystals. When the arc-shaped airbag sheet 42 loses the pressure of the pressing sheet 61, the lifting member 5 is reset under the action of its own restoring force. This reciprocating process can intermittently lift and loosen various areas of the potassium ferrate crystals.

[0181] When the trigger plate 34 loses the pressure of the carrier plate 4, the baffle 33 moves upward under the action of the spring restoring force, and at the same time pushes the inclined block of the connecting pipe 36. With the cooperation of the inclined block, the connecting pipe 36 is reset, so that the first liquid port and the second liquid port are misaligned and disconnected;

[0182] The lifting motor 12 drives the intermediate mixing chamber to move downward so that the carrier plate assembly is located in the area where the drying chamber 2 is located. Specifically, after the air inlet docking port 44 is docked with the air inlet fan 22, the heating plate 21 is started to heat the potassium ferrate crystals. The hot air flow enters the carrier plate 4 and acts on the pneumatic inclined hole 63 of the trigger ring 6 through the hot air flow, thereby causing the trigger ring 6 to rotate. During the rotation, the hot air flow is ejected from the outlet pipe 46 at an angle of 15°, thereby forming a hot air vortex, which accelerates the azeotropic coexistence of potassium ferrate crystals and cyclohexane. At the same time, by starting the vacuum pump 24, the steam in the azeotropic zone is sucked into the condensation box 23 and condensed on the 0°C mesh plate of the condensation box 23;

[0183] This reciprocating process is repeated five times to complete a washing operation process. At the same time, during the reciprocating motion, the inflatable airbag 7 continuously contracts and resets, which can provide constant pressurization for the connected liquid supply box 31. At the same time, the opening size of the connecting pipe 36 is adjusted to control the amount of cyclohexane injected into the carrier plate 4 in a single time.

Claims

1. A method for purifying high-purity potassium ferrate, characterized in that: The following steps are involved: S1. Dissolving the raw materials: Add a dilute KOH solution with a concentration of 2-6 mol / L to the crude potassium ferrate product to fully dissolve the crude potassium ferrate product; then use a funnel to filter to remove impurities and collect the filtrate for later use; S2. Recrystallization: Place the filtrate in a thermostatic water bath set at 0-30°C, continue stirring, and slowly add a 15-20 mol / L concentrated KOH solution during stirring until potassium ferrate solid precipitates from the solution. Let the solution stand at the set temperature of the thermostatic water bath for 15-90 minutes; then remove the filtrate using a funnel to obtain potassium ferrate crystals. S3, washing: washing the potassium ferrate crystals multiple times to obtain washed potassium ferrate; S4, drying: placing the washed potassium ferrate on a watch glass and drying it in a vacuum drying oven to obtain high-purity potassium ferrate; In one of the multiple washing steps, a washing process is performed using an intermittent mixing device. The non-polar solvent is sprayed multiple times and azeotropically treated with potassium ferrate crystals using an intermittent mixing method. Specifically: 1) A single dose of the non-polar solvent is 1 / 6 to 1 / 4 of the total amount of the non-polar solvent added, and the spraying temperature of the non-polar solvent is 15 to 20° C. The single dose of the non-polar solvent is sprayed and mixed with the potassium ferrate crystals; 2) After the non-polar solvent and potassium ferrate crystals are mixed once, the mixture is allowed to stand for 1 to 3 minutes, and then the potassium ferrate crystals are dried at 75° C. for 20 to 50 seconds; 3) then repeating the above steps 1)-2) to repeatedly spray and mix the potassium ferrate crystals with a single dose of non-polar solvent, allow them to stand, and dry them to complete a washing process; The mixing device comprises a mixing combination chamber for adding a non-polar solvent and azeotropically co-existing potassium ferrate crystals with the non-polar solvent, a carrier plate assembly for placing potassium ferrate crystals, and a support frame (1); The intermixing combination bin comprises a drying bin (2) and a liquid adding bin (3) arranged in sequence from top to bottom, and a detachable connecting ring (8) is provided between the drying bin (2) and the liquid adding bin (3); a support rod (11) is provided on each side of the liquid adding bin (3) in a vertical direction, and the lower end of the support rod (11) is fixedly connected to the support frame (1); a lifting motor (12) for controlling the upward and downward movement of the intermixing combination bin is provided on the support frame (1), and the output shaft of the lifting motor (12) is detachably connected to the bottom surface of the liquid adding bin (3); The carrier plate assembly is arranged inside the intermixing combination bin, and the carrier plate assembly includes a carrier plate (4) and a plurality of lifting members (5). Two connecting rods (41) are symmetrically provided on the side wall of the carrier plate (4) in the horizontal direction. The connecting rods (41) pass through the intermixing combination bin and are fixedly connected to the support rods (11). The side walls of the drying bin (2), the connecting ring (8), and the liquid adding bin (3) are provided with sliding grooves that are interconnected and used for the connecting rods (41) to slide up and down in the vertical direction. The lifting member (5) is arranged in an embedded groove provided on the inner bottom surface of the carrier (4), and an elastic membrane connected to the bottom surface of the carrier (4) is provided around the lifting member (5). The lifting member (5) includes an airbag column (51), an extension piece (52) and a connecting tube (53). One end of the extension piece (52) is fixedly connected to the upper part of the side wall of the airbag column (51), and the other end of the extension piece (52) is provided with a spring connected to the embedded groove. One end of the connecting tube (53) is fixedly connected to the lower part of the side wall of the airbag column (51), and the other end of the connecting tube (53) extends into the carrier (4). An annular cavity is provided in the side wall, wherein an arc-shaped airbag sheet (42) corresponding to the lifting member (5) is provided in the annular cavity, a trigger ring (6) is provided above the arc-shaped airbag sheet (42) and is rotatably sealed with the annular cavity, a pressing sheet (61) is provided on the lower end surface of the trigger ring (6) for squeezing the arc-shaped airbag sheet (42) by rotation, a plurality of hydraulic inclined grooves (62) are provided on the upper end surface of the trigger ring (6), and a plurality of pneumatic inclined holes (63) are provided on the side wall of the trigger ring (6) below the hydraulic inclined grooves (62); Two docking assemblies are symmetrically provided on the upper end surface of the side wall of the carrier plate (4), and the docking assembly includes a liquid inlet docking interface (43) fixed on the upper end surface of the side wall of the carrier plate (4) and an air inlet docking interface (44) arranged on one side of the liquid inlet docking interface (43) and fixed to the side wall of the carrier plate (4), one end of the liquid inlet docking interface (43) is connected to the hydraulic inclined groove (62), and the other end of the liquid inlet docking interface (43) is provided with a liquid inlet, one end of the air inlet docking interface (44) is connected to the pneumatic inclined hole (63), and the other end of the air inlet docking interface (44) is provided with an air inlet; a plurality of liquid outlet pipes (45) for connecting to the hydraulic inclined groove (62) and a plurality of air outlet pipes (46) for connecting to the pneumatic inclined hole (63) are provided on the inner side of the side wall of the carrier plate (4), and the liquid outlet pipes (45) and the air outlet pipes (46) are both arranged to be inclined downward by 15 degrees; The top surface of the drying chamber (2) is provided with a heating plate (21) and an air intake fan (22), two air intake fans (22) are provided and correspond one to one with the air intake interface (44), an air outlet duct of the air intake fan (22) passes through the drying chamber (2) and is provided with an interface with the air intake interface (44), a condensation box (23) is provided on the outside of the side wall of the drying chamber (2), an air extraction pump (24) is provided on each side of the condensation box (23), and the air extraction pump (24) is communicated with the upper part of the drying chamber (2) through a pipeline; Two liquid supply boxes (31) are provided on the inner side of the side wall of the liquid adding bin (3), and the liquid supply boxes (31) correspond to the liquid inlet interface (43) one by one. The liquid supply box (31) on the side close to the liquid inlet interface (43) is provided with a sink (32) and a baffle (33) slidably connected to the sink (32) in the vertical direction. The lower end of the baffle (33) is provided with a trigger plate (34) for cooperating with the bottom surface of the carrier (4). The side wall of the liquid supply box (31) is provided with a guide groove for moving the trigger plate (34) up and down. The lower end of the baffle (33) is provided with a spring for connecting to the inner bottom surface of the sink (32). A connecting pipe (36) is provided on the upper portion of the liquid supply box (31) in a horizontal direction. The connecting pipe (36) is slidably and sealedly connected to the pipe groove (35) of the liquid supply box (31). One end of the connecting pipe (36) is provided with a spring for connecting to the inner end surface of the pipe groove (35). The upper end surface of the connecting pipe (36) is provided with a second liquid port that is connected to the first liquid port provided at the front end of the inner top surface of the pipe groove (35) by sliding the connecting pipe (36). The first liquid port extends into the bottom of the liquid storage area of ​​the liquid supply box (31) through a curved pipe. The other end of the connecting pipe (36) and the liquid inlet are both provided with magnetic rings. The bottom surface of the connecting pipe (36) is provided with an inclined block for cooperating with the baffle (33) to move. An inflatable airbag (7) is provided at the upper and lower parts of the chute, one end of the inflatable airbag (7) is connected to the chute, and the other end of the inflatable airbag (7) is connected to the connecting rod (41). The inflatable airbag (7) is connected to a pressurizing port (37) provided on the liquid supply box (31) through a hose, and the pressurizing port (37) is communicated with the liquid storage area of ​​the liquid supply box (31); The method of described multiple washing is: 1) Primary washing: using a non-polar solvent to azeotropically remove water from the potassium ferrate crystals; wherein the non-polar solvent is any one of cyclohexane and n-hexane; 2) Secondary washing: using a polar non-aqueous solvent to remove residual inorganic salts in the potassium ferrate crystals; wherein the polar non-aqueous solvent is any one of anhydrous ethanol and anhydrous methanol; 3) Three washings: using a volatile non-polar solvent to wash and remove the solvent introduced in steps 1) and 2); wherein the volatile non-polar solvent is any one of petroleum ether, cyclohexane, and n-hexane.

2. The method for purifying high-purity potassium ferrate according to claim 1, wherein: The funnels in step S1 and step S2 are both G3 sand core funnels.

3. The method for purifying high-purity potassium ferrate according to claim 1, wherein: The potassium ferrate washed in step S4 is dried at a temperature of 45-95° C. for 1 hour.

4. The method for purifying high-purity potassium ferrate according to claim 1, wherein: The non-polar solvent is cyclohexane, the polar non-aqueous solvent is anhydrous methanol, and the volatile non-polar solvent is petroleum ether.

5. The method for purifying high-purity potassium ferrate according to claim 1, wherein: The addition ratio of the crude potassium ferrate product and the dilute KOH solution is: add 25 mL of the dilute KOH solution to every 5.00 g of the crude potassium ferrate product.

6. The method for purifying high-purity potassium ferrate according to claim 1, wherein: Cyclohexane was used as the non-polar solvent in the first washing.

7. The method for purifying high-purity potassium ferrate according to claim 1, wherein: The addition amount of the non-polar solvent, polar non-aqueous solvent and volatile non-polar solvent is: 20-60 mL of the non-polar solvent, polar non-aqueous solvent and volatile non-polar solvent is used for every 5.00 g of crude potassium ferrate product.

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