System and method for preparing 5n grade ammonium rhenate

Abstract

The application discloses a system and method for preparing 5N-grade ammonium perrhenate. The system for preparing 5N-grade ammonium perrhenate comprises a dissolving tank, a precipitation reaction tank, a buffer tank, a double-stage purification device, an ultrasonic freezing crystallization device, a centrifugal machine, a resolubilization tank and a vacuum drying oven. The double-stage filtration device comprises a top liquid inlet, a side liquid inlet, a hollow cylindrical shell, a liquid inlet chamber, a primary filtration membrane, a primary permeation chamber, a secondary filtration layer, a secondary permeation chamber, a bottom liquid outlet, a retention chamber, a liquid flow column and a discharge pipeline. The double-stage filtration device can break through the defects of the traditional filtration mode, such as easy clogging of pores and high loss rate of target products. The double-stage filtration device is used for realizing the separation of impurities by the principle of cross-flow filtration. The cross-flow filtration can protect the ion exchange membrane from being clogged. The ion exchange membrane can make up for the deficiency of the cross-flow filtration in removing small molecular ions, and basically does not produce adsorption on the ammonium perrhenate, so that the recovery rate of the ammonium perrhenate is ensured.

Description

Technical Field

[0001] This invention relates to the field of rare metal compound purification technology, and more specifically, to a system and method for preparing 5N grade ammonium perlite. Background Technology

[0002] Rhenium is a rare dispersed metal with excellent properties such as high melting point, high hardness, and corrosion resistance. It is widely used in aerospace, electronic communications, new energy and other fields, and plays an important role in national security and economic development.

[0003] Ammonium perrylate is a key raw material for preparing high-purity rhenium powder, and its purity and quality directly affect the performance of subsequent rhenium products. With the continuous development of high-end technologies, the market demand for 5N (i.e., 99.999%) grade ammonium perrylate is increasing.

[0004] Currently, the mainstream purification methods in China include recrystallization, ion exchange, and extraction. However, the current technology for preparing high-purity ammonium permanganate from crude ammonium permanganate still has many shortcomings:

[0005] The prior art 1 (publication number: CN117509739A, application date: November 6, 2023) uses an extraction-back-extraction method to prepare 5N grade ammonium perrylate, but a third phase is easily formed during the extraction process, which makes phase separation difficult, and the high-salt wastewater generated during the back-extraction process is difficult to treat.

[0006] Existing technology 2 (publication number: CN117446869A, application date: October 25, 2023) uses a multi-step ultrasonic impurity removal and recrystallization method to purify ammonium perrylate. However, this method requires multiple ultrasonic impurity removal and recrystallization processes, so the process is relatively long, and the purified ammonium perrylate can only reach the 4N (i.e. 99.99%) level.

[0007] In addition, existing technologies for ammonium perrylate crystallization mostly employ static crystallization methods, which makes it easy for impurities to be adsorbed and encapsulated during the crystal growth process, making it difficult to achieve 5N-level purity in the product.

[0008] Therefore, there is an urgent need to provide a system and method that can remove impurities, improve the purity of ammonium perrylate, and shorten the process flow. Summary of the Invention

[0009] In view of this, the present invention provides a system and method for preparing 5N grade ammonium perrylate, which removes impurities, improves the purity of ammonium perrylate, and shortens the process flow.

[0010] On one hand, the present invention provides a system for preparing 5N grade ammonium perrylate, comprising: a dissolving tank, a precipitation reaction tank, a buffer tank, a two-stage purification device, an ultrasonic cryo-crystallization device, a centrifuge, a remelting tank, and a vacuum drying oven, wherein,

[0011] The dissolving tank includes a hollow cylindrical first tank body and a first stirrer arranged along the center line of the first tank body. The first stirrer is an axial flow stirrer, including a cylindrical first stirring rod and a first blade located at the end of the first stirring rod. The first blade is a double-layer three-blade propulsion blade. The top of the first tank body is provided with a first feed inlet, the side of the first tank body near the top is provided with a first liquid inlet, and the side of the first tank body near the bottom is provided with a first liquid outlet.

[0012] The sedimentation reaction tank includes a hollow cylindrical second tank body and a second agitator arranged along the center line of the second tank body. The second agitator is an axial flow wide-blade agitator, including a cylindrical second stirring rod and a second blade located at the end of the second stirring rod. The second blade has three wide blades, and the inclination angle of the wide blades is 45°. The top of the second tank body is provided with a second feed inlet, and the side of the second tank body near the top is provided with a second liquid inlet. The second liquid inlet is connected to the first liquid outlet through a first pipe. The first pipe is provided with a first valve, and the side of the second tank body near the bottom is provided with a second liquid outlet.

[0013] The buffer tank includes a hollow cylindrical tank body. A third liquid inlet is provided on the side of the tank body near the top. The third liquid inlet is connected to the second liquid outlet through a second pipe. A second valve is provided on the second pipe. A third liquid outlet is provided on the side of the tank body near the bottom.

[0014] The dual-stage purification device includes a top liquid inlet, a side liquid inlet, a hollow cylindrical shell, an inlet chamber, a primary filter membrane, a primary permeation chamber, a secondary filter layer, a secondary permeation chamber, a bottom liquid outlet, a retention chamber, a liquid flow column, and a discharge pipe.

[0015] The top liquid inlet is provided at the top of the housing, and the top liquid inlet is connected to the third liquid outlet through a third pipe. The third pipe is equipped with a flow regulating valve to control the liquid inlet speed. The side liquid inlet is provided on the side of the housing near the top, and the bottom liquid outlet is provided on the side of the housing near the bottom.

[0016] The upper part of the shell is provided with the liquid inlet chamber, and the cross-section of the liquid inlet chamber is an inverted trapezoidal structure with the upper cross-sectional area being larger than the lower cross-sectional area. The bottom of the inverted trapezoidal structure is connected to the liquid flow column.

[0017] The liquid flow column is composed of at least two spiral hollow fiber tubes arranged side by side and extending from top to bottom. The wall material of the hollow fiber tubes is selected from one or more of latex and thermoplastic polyurethane. The bottom of the liquid flow column is connected to the discharge pipe.

[0018] The inner surface of the primary filter membrane is attached to the outer wall of the liquid flow column. The primary filter membrane is a double-layer microporous filter membrane, and its material is one or more of polytetrafluoroethylene, polyvinylidene fluoride, and polyethersulfone. The pore size of the primary filter membrane is in the range of 0.4μm to 2μm. In the horizontal direction, the space between the primary filter membrane and the shell constitutes the primary permeation chamber, and the interior of the liquid flow column corresponding to the primary filter membrane constitutes the retention chamber.

[0019] The secondary filtration layer is arranged horizontally at the bottom of the liquid flow column. The discharge pipe passes through the secondary filtration layer. The periphery of the secondary filtration layer is attached to the inner wall of the shell. The space between the secondary filtration layer and the bottom of the shell forms the secondary permeation chamber. Vertically, the secondary filtration layer includes a substrate, a microporous support, and an ion exchange membrane. The microporous support is located on the side of the substrate away from the bottom of the shell, and the ion exchange membrane is located on the side of the microporous support away from the substrate. The ion exchange membrane is a negatively charged polypiperazine amide type monovalent ion selective nanofiltration membrane with a pore size range of 0.6 nm to 1.0 nm. The vertical direction is the direction from the bottom of the shell to the top of the shell, and the vertical direction is perpendicular to the horizontal direction.

[0020] The discharge pipe is a hollow cylinder that penetrates the bottom of the shell. The discharge pipe is connected to the first liquid inlet through a fourth pipe, and a third valve is provided on the fourth pipe.

[0021] The ultrasonic cryo-crystallization device includes a fourth liquid inlet at the top and a fourth discharge outlet at the bottom. The fourth liquid inlet is connected to the bottom discharge outlet via a fifth pipe, and the fifth pipe is equipped with a fourth valve.

[0022] The centrifuge includes a fifth feed inlet at the top, a remelting outlet at the top, a fifth liquid outlet at the bottom, and a fifth discharge outlet on the side. The fifth feed inlet is connected to the fourth discharge outlet via a sixth pipe, and a fifth valve is provided on the sixth pipe. The fifth liquid outlet at the bottom is connected to the top liquid inlet via a seventh pipe, and a sixth valve is provided on the seventh pipe.

[0023] The vacuum drying oven includes a sixth inlet, which is connected to the fifth outlet via an eighth pipe;

[0024] The remelting tank includes a hollow cylindrical third tank body. The third tank body includes a seventh discharge port located on the side and a seventh inlet located at the bottom. The seventh inlet is connected to the remelting outlet through a ninth pipe. The seventh discharge port is connected to the side liquid inlet through a tenth pipe. A seventh valve is provided on the tenth pipe.

[0025] Optionally, the diameter of the first blade is 1 / 3 of the diameter of the first trough, and the distance between the bottom of the first blade and the bottom of the first trough is 0.3 times the diameter of the first blade.

[0026] Optionally, the diameter of the second blade is half the diameter of the second channel, and the distance between the bottom of the second blade and the bottom of the second channel is 0.5 times the diameter of the second blade.

[0027] Optionally, the negatively charged polypiperazine amide type monovalent ion selective nanofiltration membrane is one or more of DK, NF270, ESNA1 or TR-60.

[0028] On the other hand, the present invention also provides a method for preparing 5N grade ammonium perrylate, using the above-mentioned system, including the following steps:

[0029] The preparation of an ammonium perrylate solution includes providing crude ammonium perrylate, which is a 2N to 3N grade ammonium perrylate crystal containing impurities such as Si, K, Cu, W, Mo, and Sn; dissolving the crude ammonium perrylate in ultrapure water in a dissolving tank, filtering, and obtaining the crude ammonium perrylate solution, wherein the liquid-to-solid ratio is 2:1 to 6:1, the dissolving temperature is 40℃ to 100℃, the dissolving time is 0.5h to 3h, and the stirring speed is controlled at 100r / min to 200r / min;

[0030] The preliminary purification process using chemical precipitation includes: pumping the crude ammonium rhenium acid solution into a precipitation reaction tank, adjusting the pH value to 7-11, and adding a precipitant to the precipitation reaction tank to obtain calcium tungstate, calcium molybdate, and calcium stannate precipitates, resulting in a preliminarily purified ammonium rhenium acid solution, which is then stored in a buffer tank. The precipitant is one or more of calcium oxide, calcium hydroxide, and calcium chloride. The amount of precipitant added is 1.2 to 2.5 times the theoretical amount required for the chemical reaction. The reaction temperature is controlled at 40℃ to 100℃, the reaction time is 1 to 3 hours, and the stirring speed is controlled at 50 r / min to 150 r / min.

[0031] The dual-stage filtration for deep impurity removal includes: the pre-purified ammonium perlite solution is pumped into the dual-stage purification device from the top inlet via a transfer pump, flowing through a liquid flow column. Most of the calcium tungstate, calcium molybdate, and calcium stannate precipitates are retained in the retention chamber. The ammonium perlite solution and a small portion of ionic impurities pass through the primary filtration membrane into the primary permeation chamber. The ammonium perlite solution then passes through a secondary filtration layer to remove high-valence anionic and cationic impurities, resulting in a deeply purified ammonium perlite solution, which is then discharged through the bottom outlet into an ultrasonic freeze crystallization device. The liquid in the retention chamber is returned to the dissolving tank via a discharge pipe. The feed rate is 1 m / s to 5 m / s, and the feed temperature is 20°C to 50°C.

[0032] Ultrasonic cryo-crystallization includes: pumping the deeply purified ammonium perrylate solution into an ultrasonic cryo-crystallization device; obtaining a mixture of primary crystallizer and water through ultrasonic-temperature coordinated control; separating and drying the mixture by centrifugation to obtain primary crystallization mother liquor and primary crystals; the primary crystallization mother liquor is returned to the top inlet of the dual-stage purification device through a seventh pipe; wherein, the ultrasonic frequency is 20kHz~50kHz, the ultrasonic power is 100W~200W, the cooling equipment is a freezing chamber or a jacketed crystallization tank, the crystallization time is 8h~16h, and the crystallization temperature is -10℃~5℃;

[0033] Recrystallization includes: dissolving the primary crystal in ultrapure water in a remelting tank to obtain a secondary crystallization mother liquor; introducing the secondary crystallization mother liquor into a primary permeation chamber through a side inlet; purifying it again through a secondary filtration layer to obtain an ammonium peroxide solution; discharging it from the bottom outlet into the ultrasonic freeze crystallization device; and repeating the ultrasonic freeze crystallization and centrifugal separation steps to obtain secondary crystals.

[0034] Vacuum drying includes: vacuum drying the secondary crystallization to obtain a 5N grade ammonium perrylate product with a purity of 99.999%.

[0035] Compared with the prior art, the system and method for preparing 5N grade ammonium perrylate provided by the present invention achieves at least the following beneficial effects:

[0036] This invention provides a system for preparing 5N grade ammonium perrylate, including a dissolving tank, a precipitation reaction tank, a buffer tank, a two-stage purification device, an ultrasonic cryogenic crystallization device, a centrifuge, a remelting tank, and a vacuum drying oven. The two-stage filtration device includes a top inlet, a side inlet, a hollow cylindrical shell, an inlet chamber, a primary filter membrane, a primary permeation chamber, a secondary filter layer, a secondary permeation chamber, a bottom outlet, a retention chamber, a liquid flow column, and a discharge pipe. This system overcomes the shortcomings of traditional filtration methods, such as easy pore clogging and high loss rate of target product. Furthermore, the two-stage filtration device utilizes the principle of cross-flow filtration to separate impurities. Cross-flow filtration protects the ion exchange membrane from clogging, and the ion exchange membrane compensates for the inability of cross-flow filtration to remove small molecule ions. It also exhibits minimal adsorption of ammonium perrylate, ensuring a high ammonium perrylate recovery rate.

[0037] The present invention provides a method for preparing 5N grade ammonium perrylate, comprising the steps of: preparing ammonium perrylate solution, chemical precipitation for preliminary impurity removal, two-stage filtration for deep impurity removal, ultrasonic freeze crystallization, recrystallization and vacuum drying. The entire preparation process reduces the number of recrystallizations and is simple to operate.

[0038] This invention provides a method for preparing 5N grade ammonium perrylate, which uses ultrasound-assisted fine control of crystal growth: Compared with the traditional static crystallization method, ultrasonic freeze crystallization, by coordinating ultrasound and temperature, can match the requirements of each stage of crystallization, precisely control the crystallization process, refine the crystal grains, promote uniform distribution of solute, inhibit the encapsulation and adsorption of impurities, improve the purity and stability of the product, and ensure that the product purity reaches the 5N grade.

[0039] Of course, any product implementing this invention does not necessarily need to achieve all of the technical effects described above at the same time.

[0040] Other features and advantages of the invention will become clear from the following detailed description of exemplary embodiments of the invention with reference to the accompanying drawings. Attached Figure Description

[0041] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments of the invention and, together with their description, serve to explain the principles of the invention.

[0042] Figure 1 This is a schematic diagram of a system structure for preparing 5N grade ammonium perrylate provided by the present invention;

[0043] Figure 2 This is a schematic diagram of the structure of a two-stage purification device provided by the present invention;

[0044] Figure 3 This is a partially enlarged cross-sectional view of a secondary filter layer provided by the present invention;

[0045] Figure 4 This is a flowchart of a method for preparing 5N grade ammonium perrylate provided by the present invention. Detailed Implementation

[0046] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention.

[0047] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the invention or its application or use.

[0048] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0049] In all the examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0050] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0051] Combination Figure 1 This invention provides a system for preparing 5N grade ammonium perrylate, referring to... Figure 1 It includes: a dissolving tank 1, a precipitation reaction tank 2, a buffer tank 3, a two-stage purification device 4, an ultrasonic freezing crystallization device 5, a centrifuge 6, a remelting tank 7, and a vacuum drying oven 8.

[0052] The dissolving tank 1 is used to dissolve crude ammonium perrylate crystals. It has a hollow cylindrical first tank body 11 and a first stirrer 12 arranged along the center line of the first tank body 11. The stirrer is an axial flow stirrer with a cylindrical first stirring rod at the center. A first impeller is located at the end of the first stirring rod (i.e., the side of the first stirring rod away from the top of the dissolving tank). The first impeller is a double-layered, three-bladed propeller, meaning it has two layers of blades: an upper blade and a lower blade, with a gap between the two layers. The diameter of each blade layer is 1 / 3 of the diameter of the dissolving tank, and the distance from the bottom of the lower blade to the bottom of the tank is 0.3 times the blade diameter. This avoids dead zones in the stirring, reduces wall-attached eddies, and prevents ammonium perrylate crystals from settling and accumulating at the bottom, thus preventing localized agglomeration and undissolved crystals. The stirring speed is controlled at 100 r / min to 200 r / min when dissolving crude ammonium perrylate crystals. It should be noted that the terms "first" and "second" in this invention are only used for distinction and do not represent specific structures. Furthermore, the shape and structure of the double-layer three-bladed propeller blade in this invention are based on existing technologies, and no improvements are made to the structure of the double-layer three-bladed propeller blade. A first feed inlet 13 is provided at the top of the first tank 11 for feeding crude ammonium permanganate crystals and injecting ultrapure water into the first tank 11. A first liquid inlet 14 is provided on the side of the first tank 11 near the top. This first liquid inlet 14 is connected to the discharge pipe 412 of the dual-stage purification device 4 via a fourth pipe 41, allowing the ammonium permanganate waste liquid discharged from the dual-stage purification device 4 after dual-stage filtration to be discharged back into the dissolving tank 1 for dissolution, thus avoiding waste of ammonium permanganate and improving the recovery rate. A first liquid outlet 15 is provided on the side of the first tank 11 near the bottom, and the first liquid outlet 15 is connected to the precipitation reaction tank 2, pumping the dissolved crude ammonium permanganate solution into the precipitation reaction tank 2. The precipitation reaction tank 2 is used to add chemical reagents to induce a precipitation reaction and separate impurity ions such as W, Mo, and Sn from the pre-prepared ammonium permanganate solution. The chemical reaction formula will be detailed below. The precipitation reaction tank 2 includes a hollow cylindrical second tank body 21 and a second stirrer 22 arranged along the center line of the second tank body 21. The second stirrer 22 is an axial flow wide-blade stirrer, including a cylindrical second stirring rod and a second blade located at the end of the second stirring rod (the end of the second stirring rod away from the top of the second tank body 21). The stirrer adopts an axial flow wide-blade stirrer, and the second blade has 3 wide blades with a blade inclination angle of 45°. The diameter of the second blade is 1 / 2 of the diameter of the second tank body 21, and the distance between the bottom of the second blade and the bottom of the second tank body 21 is 0.5 times the diameter of the second blade. The stirring speed is controlled at 50 r / min to 150 r / min.The second impeller adopts a 45° inclined three-blade wide-blade axial flow structure. The impeller diameter is half the tank diameter, and the height from the bottom of the tank is 0.5 times the impeller diameter. Combined with low-speed stirring at 50 r / min to 150 r / min, this ensures rapid and uniform mixing of the precipitating agent and the pre-prepared ammonium permanganate solution, guaranteeing the full reaction of W, Mo, and Sn impurities to form precipitate flocs. It also reduces the shear intensity of the stirring, preventing the flocs from being broken and causing particle dispersion, while preventing excessive stirring of the bottom sediment. This balances precipitation reaction efficiency with subsequent solid-liquid separation and impurity removal. The second tank body 21 of the precipitation reaction tank 2 has a second feed inlet 23 at the top, a second liquid inlet 24 on the upper side of the second tank body 21, and a second liquid outlet 25 on the lower side of the second tank body 21. The second liquid inlet 24 is connected to the first liquid outlet 15 via a first pipe 17, and a first valve 18 is installed on the first pipe 17.

[0053] The structure of the second stirrer 22 in this invention adopts the structure of the prior art, but the structure is improved here. For example, the structure of the second stirrer 22 can adopt the structure of the prior art (publication number: CN216498640U, application date: 2021.12.24).

[0054] The buffer tank 3 is used to regulate the flow rate of ammonium perrylate solution entering the dual-stage purification device 4. The buffer tank 3 includes a hollow cylindrical tank body. A third liquid inlet 31 is provided on the side of the tank body near the top. The third liquid inlet 31 is connected to the second liquid outlet 25 of the precipitation reaction tank 2 through a second pipe 26. A second valve 27 is provided on the second pipe 26. A third liquid outlet 32 ​​is provided on the side of the tank body near the bottom. The third liquid outlet 32 ​​is connected to the top liquid inlet 401 at the top of the dual-stage purification device 4.

[0055] The dual-stage purification device 4 is used to filter and separate solid particulate impurities such as calcium tungstate, calcium molybdate, and calcium stannate from the suspension generated by the precipitation reaction tank 2 in one step, and to remove trace amounts of W, Mo, and other impurity ions from the solution, resulting in a deeply purified ammonium rheniumate solution. (Refer to...) Figure 2 The dual-stage purification device includes a top liquid inlet 401, a side liquid inlet 402, a hollow cylindrical shell, a liquid inlet chamber 404, a primary filter membrane 405, a primary permeation chamber 406, a secondary filter layer 408, a secondary permeation chamber 407, a bottom liquid outlet 409, a retention chamber 410, a liquid flow column 411, and a discharge pipe 412.

[0056] The dual-stage purification device 4 has an upper and lower structure. The uppermost part is the liquid inlet chamber 404, which has a trapezoidal structure. The cross-sectional area of ​​the liquid inlet chamber 404 is larger at the upper end than at the lower end. The material of the liquid inlet chamber 404 is stainless steel lined with polytetrafluoroethylene. The top of the dual-stage purification device 4 has a top liquid inlet 401, and the lower end is connected to the liquid flow column 411. The liquid flow column 411 is composed of several spiral tubes, which are vertically installed inside the shell. The upper end is connected to the bottom of the liquid inlet chamber 404, and the lower end is connected to the lower shell wall of the dual-stage purification device 4. The inner surface of the primary filter membrane 405 is fixedly attached to the curved surface of the outer wall of the liquid flow column 411. The secondary filter layer 408 includes a substrate 4081, an ion exchange membrane 4083, and a microporous support 4082. The substrate 4081 is made of polypropylene (PP) or polyvinylidene fluoride (PVDF), and the microporous support 4082 is made of... The material is selected from polyvinylidene fluoride (PVDF) or polyethersulfone (PES), with a micropore size range of 0.2μm to 1.0μm; the upper side is a primary permeation chamber 406, and the lower side is a secondary permeation chamber 407; the wall of the liquid flow column 411 is selected from one or more of latex and thermoplastic polyurethane; the primary filter membrane 405 is a double-layer microporous filter membrane; the top cover plate of the primary permeation chamber 406 is provided with a top liquid inlet 401, and the side wall of the secondary permeation chamber 407 is provided with a bottom liquid outlet 409; the retained liquid in the retention chamber 410 is finally collected in the discharge pipe 412 and returned to the dissolving tank 1 through the fourth pipe 41. The liquid flow column 411 is composed of at least two parallel spiral hollow fiber tubes extending from top to bottom. The wall material of the hollow fiber tubes is selected from one or more of latex and thermoplastic polyurethane. The primary filter membrane 405 is a double-layer microporous filter membrane. The membrane material is selected from one or more of polytetrafluoroethylene, polyvinylidene fluoride and polyethersulfone. The membrane pore size ranges from 0.4μm to 2μm. It is used to filter and separate solid particulate impurities such as calcium tungstate, calcium molybdate and calcium stannate in suspension.

[0057] The secondary filter layer 408 employs a negatively charged polypiperazine amide type monovalent ion selective nanofiltration membrane with a pore size range of 0.6 nm to 1.0 nm, specifically selected from one or more of DK, NF270, ESNA1, or TR-60 membranes. This membrane allows monovalent cations NH4+ to pass through a synergistic effect of pore size sieving and electrostatic repulsion. + With monovalent anion ReO4 - Simultaneous transmission, while intercepting WO4 2- MoO4 2- High-valence anions and Ca 2+ Sn 2+ Cu 2+Cations and other impurities are eliminated, and a deeply purified ammonium rheniumate solution is obtained in the secondary permeation chamber 407. An annular step is provided on the inner wall of the shell for limiting the flow. The outer edge of the secondary filter layer 408 rests on the step, and a pressure ring is used to press down on the periphery of the secondary filter layer 408. A sealing ring is added between the pressure ring and the secondary filter layer 408 to further seal and prevent liquid cross-contamination.

[0058] The top cover of the primary permeation chamber 406 is provided with a top liquid inlet 401, and the side wall of the secondary permeation chamber 407 is provided with a bottom liquid outlet 409. The retained liquid in the retention chamber 410 is finally collected in the discharge pipe 412 and returned to the dissolution tank 1 through the discharge pipe 412.

[0059] The ultrasonic cryo-crystallization apparatus 5 provides a crystallization environment for the uniform crystallization of ammonium perrylate solution. Its structure utilizes existing equipment, and no modifications are made to the structure of the ultrasonic cryo-crystallization apparatus here. The ultrasonic cryo-crystallization apparatus 5 includes a fourth inlet 51 at the top and a fourth outlet 52 at the bottom. The fourth inlet 51 is connected to the bottom outlet 409 of the dual-stage purification device 4 via a fifth pipe 53. The fifth pipe 53 is equipped with a fourth valve 54. The fourth outlet 52 is connected to the centrifuge 6 via a sixth pipe 55, pumping the primary crystallization and the primary crystallization mother liquor into the centrifuge 6.

[0060] Centrifuge 6 is used for solid-liquid separation in ammonium perrylate crystallization, separating the primary crystallization and mother liquor discharged from the ultrasonic cryogenic crystallization device 5. Its structure adopts existing equipment, and no modifications are made to the structure of centrifuge 6. Centrifuge 6 includes a fifth feed inlet 61 at the top, a return dissolution outlet 62 at the top, a fifth liquid outlet 63 at the bottom, and a fifth discharge outlet 64 on the side. The fifth feed inlet 61 is connected to the fourth discharge outlet 52 of the ultrasonic cryogenic crystallization device 5 via a sixth pipe 55, which is equipped with a fifth valve 56. The fifth liquid outlet 63 at the bottom is connected to the top inlet 401 of the dual-stage purification device 4 via a seventh pipe 65. The mother liquor from the primary crystallization returns to the dual-stage purification device 4 from the top inlet 401 via the seventh pipe 65. The primary crystallized material returns to the return dissolution tank 7 via the top return dissolution outlet 62 and the ninth pipe 66. The fifth discharge port 64 located on the side is connected to the vacuum drying oven 8 through the eighth pipe 67, and the secondary crystallization is dried in the vacuum drying oven 8.

[0061] The remelting tank 7 is used to dissolve the primary crystals. The remelting tank 7 includes a hollow cylindrical third tank body 71. The third tank body 71 includes a seventh discharge port 72 located on the side and a seventh feed port 73 located at the bottom. The seventh feed port 72 is connected to the remelting outlet 62 at the top of the centrifuge 6 through a ninth pipe 66. The primary crystals are returned to the remelting tank 7 and dissolved again with ultrapure water to obtain secondary crystallization mother liquor. The seventh discharge port 72 is connected to the side liquid inlet 402 through a tenth pipe 74. The secondary crystallization mother liquor is pumped into the first-stage permeation chamber of the dual-stage purification device 4 through the tenth pipe 74. A seventh valve 75 is provided on the tenth pipe 74.

[0062] Vacuum drying oven 8 is used to dry ammonium permanganate crystals to obtain 5N grade ammonium permanganate product. The vacuum drying oven adopts the structure of the prior art, and no changes are made to the structure of the vacuum drying oven here. Vacuum drying oven 8 includes a sixth feed port 81, which is connected to the fifth discharge port 64 of centrifuge 6 through an eighth pipe 67 to dry secondary crystals.

[0063] In practice, crude ammonium perrylate crystals (2N or 3N grade) are dissolved in dissolving tank 1 and then pumped into precipitation reaction tank 2. In precipitation reaction tank 2, ammonia water is added beforehand to adjust the pH to the required value, and then a precipitant is added to cause a precipitation reaction. After the reaction, the ammonium perrylate solution carrying a small amount of solid particles is pumped into buffer tank 3 for buffering. Then, it enters the dual-stage filtration device 4 through the top inlet 401 via the third pipe 33. After entering the dual-stage filtration device 4, it enters the inlet chamber 404 for further buffering and then is diverted to several spiral liquid flow columns 411. The spiral liquid flow columns can increase the flow contact time and contact area between the solution and the primary filter membrane 405. As the suspension flows from top to bottom, most of the solid particles are trapped in the trapping chamber 410. Ammonium peroxide solution and a small amount of ionic impurities pass through the primary filter membrane 405 into the primary permeation chamber 406, and then undergo secondary purification through the secondary filter layer 408. Trace amounts of W, Mo and other impurity ions are retained, resulting in pure ammonium peroxide liquid in the secondary permeation chamber. This liquid is then transported to the ultrasonic cryogenic crystallization device 5 through the bottom outlet 409. After crystallization, primary crystallization and primary mother liquor are obtained. The primary crystallization and primary mother liquor are pumped to the centrifuge 6 for centrifugation and drying. The primary mother liquor returns to the dual-stage purification device 4 through the seventh pipe 65 from the top inlet 401. The primary crystallization is sent to the return dissolution tank 7 for dissolution, and then transported to the side inlet 402 of the dual-stage purification device 4 through the tenth pipe 74. The secondary purification-crystallization-drying operations are repeated, and then the liquid is dried in a vacuum drying oven to obtain 5N grade ammonium peroxide crystals.

[0064] Combination Figure 4 and reference Figures 1 to 3 This invention provides a method for preparing 5N ammonium perrylate, using the above-mentioned... Figures 1 to 3 The system is prepared using the following steps:

[0065] S1. Preparation of ammonium perrylate solution: Place crude ammonium perrylate crystals in a dissolving tank, dissolve the crude ammonium perrylate in ultrapure water, and filter to obtain a crude ammonium perrylate solution. The liquid-to-solid ratio is controlled at 2:1 to 6:1, the dissolving temperature is 40 to 100℃, and the dissolving time is 0.5 h to 3 h.

[0066] Crude ammonium peroxide is a 2N to 3N grade of ammonium peroxide crystals containing trace amounts of impurities such as Si, K, Cu, W, Mo, and Sn.

[0067] Here, 2N grade refers to a content of 99%, and 3N grade refers to a content of 99.9%.

[0068] Optionally, filtration is performed using a bag filter. The bag filter housing and internal support basket are both made of 316L stainless steel, with a built-in PP or PE filter bag. Under pressure, the crude ammonium permeate solution permeates from the inside of the filter bag to the outside. Solid particles with a particle size greater than 1μm to 5μm, as well as colloidal suspended matter of silicon and metal oxides, are trapped inside the filter bag. The filtered clarified liquid is then sent to the subsequent precipitation reaction tank.

[0069] S2, Preliminary Chemical Precipitation for Impurity Removal: A crude ammonium rheniumate solution is pumped into a precipitation reaction tank, and analytical grade ammonia is added to adjust the pH to 7-11. Then, one or more precipitants—calcium oxide, calcium hydroxide, and calcium chloride—are added, with a purity of analytical grade or higher. The amount of precipitant added is 1.2-2.5 times the theoretical amount. The reaction is stirred at 50-150 rpm for 1-3 hours to obtain precipitates such as calcium tungstate, calcium molybdate, and calcium stannate, thus achieving preliminary impurity removal. The resulting ammonium rheniumate solution contains low levels of tungsten, molybdenum, and tin. The main chemical reaction equations during the precipitation process are as follows:

[0070] Cu 2+ +2OH - →Cu(OH)2↓;

[0071] Ca 2+ +WO4 2- →CaWO4↓;

[0072] Ca 2+ +MoO4 2- →CaMoO4↓;

[0073] Ca 2+ +Sn(OH)4 2- →CaSnO3↓+3H2O;

[0074] Ca 2+ +SiO3 2- →CaSiO3↓;

[0075] Ca2+ +Sn(OH)6 2- →CaSnO3↓+3H2O.

[0076] It should be noted that if the amount of precipitating reagent used is too low, impurities will not precipitate completely; if the amount used is too high, there will be an excessive amount of calcium ions, wasting reagent and increasing the subsequent desalination load. In this invention, the amount of precipitating agent added is 1.2 to 2.5 times the theoretical amount, which ensures complete precipitation without wasting reagent.

[0077] The stirring time can be 50 r / min, 60 r / min, 70 r / min, 80 r / min, 90 r / min, 100 r / min, 110 r / min, 120 r / min, 1300 r / min, 140 r / min, or 150 r / min, or a range between any two points between 50 r / min and 150 r / min, such as 80 r / min to 120 r / min.

[0078] The reaction time can be 1h, 1.5h, 2h, 2.5h or 3h, or it can be a range between any two points between 1h and 3h.

[0079] S3, Dual-stage filtration for deep impurity removal: The pre-purified ammonium peroxide solution is pumped into the inlet chamber of the dual-stage filtration device from the top inlet. Flowing through the liquid flow column, most of the calcium tungstate, calcium molybdate, and calcium stannate precipitates are retained in the retention chamber. The ammonium peroxide solution and a small amount of ionic impurities pass through the primary filtration membrane into the primary permeation chamber. The ammonium peroxide solution then passes through the secondary filtration layer to remove high-valence anionic and cationic impurities, resulting in a deeply purified ammonium peroxide solution. This solution then enters the ultrasonic freeze crystallization device through the bottom outlet. The liquid in the retention chamber is returned to the dissolving tank via the discharge pipe. The feed rate is controlled at 1 m / s to 5 m / s, and the temperature at 20°C to 50°C. The purified solution enters the freeze crystallization tank through the outlet, and the retained liquid returns to the dissolving tank via the discharge pipe.

[0080] The feed rate should be controlled between 1 m / s and 5 m / s. For example, the feed rate can be 1 m / s, 2 m / s, 3 m / s, 4 m / s, or 5 m / s. It should be noted that if the feed rate is too low, particles may settle and clog the pores; if the feed rate is too high, the filtration efficiency will decrease.

[0081] The temperature range is 20℃ to 50℃, selectable values ​​such as 20℃, 25℃, 30℃, 35℃, 40℃, 45℃, or 50℃. It can also be a range between any two points within the 20℃ to 50℃ range, such as 30℃ to 40℃. 20℃ to 50℃ is the operating range for the primary and secondary filtration layers. If the temperature is too low, the membrane flux drops sharply, and the filtration efficiency deteriorates; if the temperature is too high, the membrane material is prone to thermal aging, shrinkage, and deformation.

[0082] S4, Ultrasonic Freeze-Crystallization: A deeply purified ammonium perrylate solution is pumped into an ultrasonic freeze-crystallization device. A mixture of primary crystals and water is obtained through ultrasonic-temperature coordinated control. This mixture is then separated and dried using a centrifuge, separating the primary crystallization mother liquor and the primary crystals. The primary crystallization mother liquor returns to the top inlet of the dual-stage purification device via a seventh pipe. The ultrasonic crystallization device frequency is controlled at 20kHz~50kHz, and the ultrasonic power at 100W~200W. The cooling equipment uses a freezing chamber or a jacketed crystallization tank. The ultrasonic-temperature coordinated control crystallization time is 8h~16h, and the crystallization temperature is -10℃~5℃.

[0083] The ultrasonic crystallization device can operate at frequencies of 20kHz, 30kHz, 40kHz, or 50kHz, or within any range between 20kHz and 50kHz. The ultrasonic power can be 100W, 150W, or 200W. The crystallization time can be 8h, 9h, 10h, 11h, 12h, 13h, 14h, 15h, or 16h, or within any range between 8h and 16h, for example, 10h-15h. The crystallization temperature can be -10℃, -5℃, 0℃, or 5℃, or within any range between -10℃ and 5℃.

[0084] S5, recrystallization: The primary crystallizer is dissolved again in ultrapure water in the remelting tank to obtain secondary crystallization mother liquor. The liquid-to-solid ratio is 2:1 to 6:1, the dissolution temperature is 40℃ to 100℃, and the dissolution time is 0.5h to 3h. The secondary crystallization mother liquor enters the first-stage permeation chamber of the dual-stage purification device through the side inlet. It is then purified again through the second-stage filtration layer to obtain ammonium perrylate solution. It is then discharged from the bottom outlet into the ultrasonic cryogenic crystallization device for secondary crystallization. After centrifugation, the secondary crystals are obtained.

[0085] The liquid-to-solid ratio can be 2:1, 3:1, 4:1, 5:1, or 6:1, or any value between 2:1 and 6:1. The dissolution temperature can be 40℃, 50℃, 60℃, 70℃, 80℃, 90℃, or 100℃, or any value between 40℃ and 100℃. The dissolution time can be 0.5h, 1h, 1.5h, 2h, 2.5h, or 3h, or any value between 0.5h and 3h.

[0086] S6, Vacuum drying: The secondary crystals are placed in a vacuum drying oven and dried under vacuum to obtain 5N grade ammonium rhenium with a purity of 99.999%. The drying temperature is controlled at 70℃~110℃ and the drying time is 12h~24h.

[0087] Controlling the drying temperature to 70℃~110℃ and the drying time to 12h~24h can ensure that the crystals are fully dried.

[0088] Example 1

[0089] This embodiment provides a method for preparing 5N ammonium perrylate, the process of which is as follows: Figure 4 As shown, using Figures 1 to 3 The apparatus shown includes the following steps:

[0090] S101, add 100L of ultrapure water to the dissolving tank, heat to 40℃, add 50kg of crude ammonium perlite product, with a liquid-to-solid ratio of 2:1, wherein the crude ammonium perlite has a main grade of 99.9%, and the contents of the main impurity elements are: W 0.0215%, Mo 0.0452%, Sn 0.0078%, Si 0.0035%, K 0.0052%, and Cu 0.0076%; stir at 200r / min for 0.5 h to completely dissolve it, thus preparing a crude ammonium perlite solution;

[0091] S102, pump the crude ammonium perlite solution into the precipitation reaction tank, add ammonia water to adjust the pH to 8, slowly add 52g of analytical grade calcium chloride (1.2 times the theoretical amount of chemical reaction) to the crude ammonium perlite solution, heat to 40℃ and stir at 150r / min for 1h to precipitate small amounts of W, Mo, Sn and other elements in the crude crystals, and obtain a preliminarily purified ammonium perlite solution, which is then pumped into a buffer tank;

[0092] S103, once the solution temperature in the buffer tank drops to 20℃, the liquid is pumped into a two-stage filtration device. The first-stage filtration membrane in the two-stage purification device uses polytetrafluoroethylene material with a pore size of 0.4μm, and the second-stage filtration membrane uses DK membrane with a pore size of 0.6nm. The feed rate is controlled to 1m / s by the flow regulating valve. The deeply purified ammonium perrylate solution is obtained from the bottom outlet 409, and the retentate is returned to the dissolving tank 1 for recycling.

[0093] S4. Pump the deeply purified ammonium perrylate solution into an ultrasonic freezing device for freezing and crystallization. Set the ultrasonic frequency to 20 kHz, the ultrasonic power to 100 W, and the freezing chamber temperature to -10 °C. After ultrasonic crystallization for 4 hours, turn off the ultrasonic device and continue freezing and standing in the freezing chamber for 4 hours. Separate the primary crystallizer and the primary mother liquor using a centrifuge. Rinse the crystallizer twice with room temperature ultrapure water in the centrifuge to obtain the primary crystallizer.

[0094] S5. Dissolve the primary crystals again in ultrapure water in the remelting tank, controlling the solid-solid ratio of the solution to be 2:1 and the temperature to be 40℃. Dissolve for 0.5 hours. Repeat the unit operations of secondary purification, freeze crystallization, and spin drying under the same operating conditions as above to obtain secondary crystals.

[0095] S106, the secondary crystallizer is placed in a vacuum drying oven, the drying temperature is controlled at 70℃, and the drying time is 12h to obtain ammonium rhenium product with a main grade greater than or equal to 99.999%. The contents of the main impurity elements are as follows: W 0.000023%, Mo 0.000056%, Sn 0.000054%, Si 0.00028%, K 0.000046%, and Cu 0.000057%.

[0096] Example 2

[0097] S201. Add 200L of ultrapure water to the dissolving tank and heat to 80℃. Add 50 kg of crude ammonium perlite product at a liquid-to-solid ratio of 4:1. The crude ammonium perlite has a main purity of 99.9%, and the main impurity elements are: W 0.0215%, Mo 0.0452%, Sn 0.0078%, Si 0.0035%, K 0.0052%, and Cu 0.0076%. Stir at 100r / min for 2 h to completely dissolve the product and prepare a crude ammonium perlite solution.

[0098] S202, pump the ammonium perrylate solution into the precipitation reaction tank, add ammonia water to adjust the pH to 8, slowly add 86.6g of analytical grade calcium chloride (twice the theoretical amount) to the crude ammonium perrylate solution, heat to 80 ℃ and stir at 150 r / min for 2h to precipitate small amounts of W, Mo, Sn and other elements in the crude crystals, and obtain a preliminarily purified ammonium perrylate solution, which is then pumped into buffer tank 3;

[0099] S203, once the solution temperature in the buffer tank drops to 30℃, the liquid is pumped into a two-stage filtration device. The first-stage filtration membrane in the two-stage purification device uses polytetrafluoroethylene material with a pore size of 0.6 microns, and the second-stage filtration membrane uses NF270 membrane with a pore size of 0.6nm. The feed rate is controlled at 2.5m / s by a flow regulating valve. The deeply purified ammonium perrylate solution is obtained from the bottom outlet, and the retentate is returned to the dissolving tank for recycling.

[0100] S204. The deeply purified ammonium perrylate solution was pumped into an ultrasonic freezing device for freezing and crystallization. The ultrasonic frequency was set to 30 kHz, the ultrasonic power to 150 W, and the freezing chamber temperature to 0 °C. After ultrasonic crystallization for 4 hours, the ultrasonic device was turned off, and the solution was allowed to stand in the freezing chamber for another 6 hours. The primary crystallization and the primary mother liquor were separated into solid and liquid components using a centrifuge. The crystallized solution was washed twice with room temperature ultrapure water in the centrifuge to obtain the primary crystallization.

[0101] S205, the primary crystallizer is dissolved again in ultrapure water in the remelting tank, the solid-liquid ratio is controlled at 4:1, the temperature is 80℃, and the dissolution time is 2h. The secondary purification, freeze crystallization, and spin drying are repeated under the same operating conditions as above to obtain secondary crystallizer.

[0102] S206, the secondary crystallizer is placed in a vacuum drying oven, the drying temperature is controlled at 80℃, and the drying time is 18 h to obtain ammonium rhenium product with a main grade greater than or equal to 99.999%. The contents of the main impurity elements are as follows: W 0.000009%, Mo 0.000012%, Sn 0.000016%, Si 0.00025%, K 0.000072%, and Cu 0.000035%.

[0103] Example 3

[0104] S301. Add 300L of ultrapure water to the dissolving tank and heat to 80℃. Add 50 kg of crude ammonium perlite product at a liquid-to-solid ratio of 6:1. The crude ammonium perlite has a main purity of 99.9%, and the main impurity elements are: W 0.0215%, Mo 0.0452%, Sn 0.0078%, Si 0.0035%, K 0.0052%, and Cu 0.0076%. Stir at 150r / min for 3 h to completely dissolve the product and prepare a crude ammonium perlite solution.

[0105] S302, pump the ammonium perrylate solution into the precipitation reaction tank, add ammonia water to adjust the pH to 11, slowly add 108.25g of analytical grade calcium chloride (2.5 times the theoretical amount) to the crude ammonium perrylate solution, heat to 100 ℃ and stir at 50 r / min for 3 h to precipitate small amounts of W, Mo, Sn and other elements in the crude crystals, and obtain a preliminarily purified ammonium perrylate solution, which is then pumped into a buffer tank;

[0106] S303, once the solution temperature in the buffer tank drops to 50℃, the liquid is pumped into a two-stage filtration device. The first-stage filtration membrane in the two-stage purification device uses polytetrafluoroethylene material with a pore size of 1 micron, and the second-stage filtration membrane uses an ESNA1 membrane with a pore size of 1nm. The feed rate is controlled at 5m / s by a flow regulating valve. A deeply purified ammonium perrylate solution is obtained from the bottom outlet, and the retentate is returned to the dissolving tank for recycling.

[0107] S304. The deeply purified ammonium perrylate solution was pumped into an ultrasonic freezing device for freezing and crystallization. The ultrasonic frequency was set to 50 kHz, the ultrasonic power to 200 W, and the freezing chamber temperature to -10 ℃. After ultrasonic crystallization for 10 hours, the ultrasonic device was turned off, and the solution was allowed to stand in the freezing chamber for another 14 hours. The primary crystallization and the primary mother liquor were separated into solid and liquid components using a centrifuge. The crystallized solution was washed twice with room temperature ultrapure water in the centrifuge to obtain the primary crystallization.

[0108] S305, the primary crystal is dissolved again in ultrapure water in the remelting tank, the solid-liquid ratio is controlled at 6:1, the temperature is 100℃, and the dissolution time is 3h. The secondary purification, freeze crystallization, and spin drying are repeated under the same operating conditions as above to obtain secondary crystals.

[0109] S306, the secondary crystallizer is placed in a vacuum drying oven, and the drying temperature is controlled at 110℃ for 24 h to obtain ammonium rhenium product with a main grade greater than or equal to 99.999%. The contents of the main impurity elements are as follows: W 0.000079%, Mo 0.000012%, Sn 0.000032%, Si 0.00045%, K 0.00015%, and Cu 0.000012%.

[0110] Example 4

[0111] S401. Add 200L of ultrapure water to the dissolving tank, heat to 80℃, add 50kg of crude ammonium perrhenate product, with a liquid-to-solid ratio of 4:1, stir at 150r / min for 2h to completely dissolve it, and prepare a crude ammonium perrhenate solution; wherein, the crude ammonium perrhenate has a main grade of 99.9%, and the contents of the main impurity elements are as follows: W 0.0215%, Mo 0.0452%, Sn 0.0078%, Si 0.0035%, K 0.0052%, and Cu 0.0076%.

[0112] S402. Pump the crude ammonium perrylate solution into the precipitation reaction tank, add ammonia water to adjust the pH to 8, slowly add 57.8g of analytical grade calcium hydroxide (twice the chemical theoretical reaction amount) to the crude ammonium perrylate solution, heat to 80℃ and stir at 80r / min for 2h to precipitate small amounts of W, Mo, Sn and other elements in the crude crystals, and obtain a preliminarily purified ammonium perrylate solution, which is then pumped into a buffer tank.

[0113] S403. When the temperature of the solution in the buffer tank drops to 30°C, the liquid is pumped into a two-stage filtration device. The first-stage filtration membrane in the two-stage purification device is made of polytetrafluoroethylene material with a pore size of 0.45 micrometers, and the second-stage filtration membrane is made of DK membrane with a pore size of 0.8 nm. The feed rate is controlled at 2.5 m / s by the flow regulating valve. The deeply purified ammonium perrylate solution is obtained from the bottom outlet, and the retentate is returned to the dissolving tank 1 for recycling.

[0114] S404. The deeply purified ammonium perrylate solution is pumped into an ultrasonic freezing device for freezing and crystallization. The ultrasonic frequency is set to 30 kHz, the ultrasonic power is 150 W, and the freezing chamber temperature is 0 ℃. After ultrasonic crystallization for 4 hours, the ultrasonic device is turned off, and the solution is allowed to stand in the freezing chamber for another 6 hours. The primary crystallization and the primary mother liquor are separated into solid and liquid components using a centrifuge. The crystallization is washed twice with room temperature ultrapure water in the centrifuge to obtain the primary crystallization.

[0115] S405, the primary crystal is dissolved again in ultrapure water in the remelting tank, the solid-liquid ratio is controlled at 4:1, the temperature is 80℃, and the dissolution time is 2h. The secondary purification, freeze crystallization, and spin drying are repeated under the same operating conditions as above to obtain secondary crystals.

[0116] S406, the secondary crystallizer is placed in a vacuum drying oven, the drying temperature is controlled at 80℃, and the drying time is 18 h to obtain ammonium rhenium product with a main grade greater than or equal to 99.999%. The contents of the main impurity elements are as follows: W 0.000059%, Mo 0.000043%, Sn 0.000026%, Si 0.00035%, K 0.000052%, and Cu 0.000066%.

[0117] To illustrate the practical effects of the present invention, two sets of comparative experiments were also conducted:

[0118] Comparative Example 1

[0119] This comparative example 1 compares the impact of traditional filtration methods and the two-stage filtration method described in this invention on the quality of ammonium perrylate products.

[0120] S011, dissolve the crude crystals of ammonium perrylate by heating;

[0121] S012, then pump the ammonium perrylate solution into the precipitation reaction tank for chemical precipitation;

[0122] S013, the ammonium perrylate solution after precipitation is vacuum filtered;

[0123] S014, pump the ammonium perrylate solution into an ultrasonic freezing device for cryopreservation and crystallization, and repeat steps S015-S016.

[0124] The parameters for processes S011, S012, S014, S015, and S016 are completely consistent with those in Example 1. The test results of the obtained ammonium rheniumate product are as follows:

[0125] The main grade of ammonium perrylate is 99.991%, and the contents of the main impurity elements are as follows: W 0.00036%, Mo 0.00073%, Sn 0.0046%, Si 0.0065%, K 0.00072%, and Cu 0.00086%.

[0126] Comparative Example 2

[0127] This comparative study examines the impact of traditional freeze crystallization methods and the crystallization method described in this invention on the quality of ammonium perrylate products.

[0128] S021, dissolve the crude crystals of ammonium perrylate by heating.

[0129] S022, then the ammonium perrylate solution is pumped into the precipitation reaction tank for chemical precipitation.

[0130] S023, the liquid is pumped into a two-stage filtration device for deep purification.

[0131] S024, freeze crystallize the ammonium perryate solution at 0°C for 10 hours. Separate the primary crystallizer and the primary mother liquor using a centrifuge. Wash the crystallizer twice with room temperature ultrapure water in the centrifuge to obtain the primary crystallizer. Repeat steps S025-S026 to obtain the ammonium perryate product.

[0132] The parameters for processes S021, S022, S023, and S025-S026 in the two comparative examples above are completely consistent with those in Example 1. The test results of the obtained ammonium rheniumate product are as follows:

[0133] Comparative Example 2: The main grade of ammonium perrylate product is 99.997%, and the contents of the main impurity elements are as follows: W 0.00021%, Mo 0.00033%, Sn 0.0032%, Si 0.0065%, K 0.00045%, and Cu 0.00051%.

[0134] While specific embodiments of the invention have been described in detail by way of examples, those skilled in the art should understand that the examples are for illustrative purposes only and not intended to limit the scope of the invention. Those skilled in the art should understand that modifications can be made to the above embodiments without departing from the scope and spirit of the invention. The scope of the invention is defined by the appended claims.

Claims

1. A system for preparing 5N grade ammonium perrylate, characterized in that, include: The equipment includes a dissolving tank, a precipitation reaction tank, a buffer tank, a two-stage purification device, an ultrasonic freeze crystallization device, a centrifuge, a remelting tank, and a vacuum drying oven. The dissolving tank includes a hollow cylindrical first tank body and a first stirrer arranged along the center line of the first tank body. The first stirrer is an axial flow stirrer, including a cylindrical first stirring rod and a first blade located at the end of the first stirring rod. The first blade is a double-layer three-blade propulsion blade. The top of the first tank body is provided with a first feed inlet, the side of the first tank body near the top is provided with a first liquid inlet, and the side of the first tank body near the bottom is provided with a first liquid outlet. The sedimentation reaction tank includes a hollow cylindrical second tank body and a second agitator arranged along the center line of the second tank body. The second agitator is an axial flow wide-blade agitator, including a cylindrical second stirring rod and a second blade located at the end of the second stirring rod. The second blade has three wide blades, and the inclination angle of the wide blades is 45°. The top of the second tank body is provided with a second feed inlet, and the side of the second tank body near the top is provided with a second liquid inlet. The second liquid inlet is connected to the first liquid outlet through a first pipe. The first pipe is provided with a first valve, and the side of the second tank body near the bottom is provided with a second liquid outlet. The buffer tank includes a hollow cylindrical tank body. A third liquid inlet is provided on the side of the tank body near the top. The third liquid inlet is connected to the second liquid outlet through a second pipe. A second valve is provided on the second pipe. A third liquid outlet is provided on the side of the tank body near the bottom. The dual-stage purification device includes a top liquid inlet, a side liquid inlet, a hollow cylindrical shell, an inlet chamber, a primary filter membrane, a primary permeation chamber, a secondary filter layer, a secondary permeation chamber, a bottom liquid outlet, a retention chamber, a liquid flow column, and a discharge pipe. The top liquid inlet is provided at the top of the housing, and the top liquid inlet is connected to the third liquid outlet through a third pipe. The third pipe is equipped with a flow regulating valve to control the liquid inlet speed. The side liquid inlet is provided on the side of the housing near the top, and the bottom liquid outlet is provided on the side of the housing near the bottom. The upper part of the shell is provided with the liquid inlet chamber, and the cross-section of the liquid inlet chamber is an inverted trapezoidal structure with the upper cross-sectional area being larger than the lower cross-sectional area. The bottom of the inverted trapezoidal structure is connected to the liquid flow column. The liquid flow column is composed of at least two spiral hollow fiber tubes arranged side by side and extending from top to bottom. The wall material of the hollow fiber tubes is selected from one or more of latex and thermoplastic polyurethane. The bottom of the liquid flow column is connected to the discharge pipe. The inner surface of the primary filter membrane is attached to the outer wall of the liquid flow column. The primary filter membrane is a double-layer microporous filter membrane, and its material is one or more of polytetrafluoroethylene, polyvinylidene fluoride, and polyethersulfone. The pore size of the primary filter membrane is in the range of 0.4μm to 2μm. In the horizontal direction, the space between the primary filter membrane and the shell constitutes the primary permeation chamber, and the interior of the liquid flow column corresponding to the primary filter membrane constitutes the retention chamber. The secondary filtration layer is arranged horizontally at the bottom of the liquid flow column. The discharge pipe passes through the secondary filtration layer. The periphery of the secondary filtration layer is attached to the inner wall of the shell. The space between the secondary filtration layer and the bottom of the shell forms the secondary permeation chamber. Vertically, the secondary filtration layer includes a substrate, a microporous support, and an ion exchange membrane. The microporous support is located on the side of the substrate away from the bottom of the shell, and the ion exchange membrane is located on the side of the microporous support away from the substrate. The ion exchange membrane is a negatively charged polypiperazine amide type monovalent ion selective nanofiltration membrane with a pore size range of 0.6 nm to 1.0 nm. The vertical direction is the direction from the bottom of the shell to the top of the shell, and the vertical direction is perpendicular to the horizontal direction. The discharge pipe is a hollow cylinder that penetrates the bottom of the shell. The discharge pipe is connected to the first liquid inlet through a fourth pipe, and a third valve is provided on the fourth pipe. The ultrasonic cryo-crystallization device includes a fourth liquid inlet at the top and a fourth discharge outlet at the bottom. The fourth liquid inlet is connected to the bottom discharge outlet via a fifth pipe, and the fifth pipe is equipped with a fourth valve. The centrifuge includes a fifth feed inlet at the top, a remelting outlet at the top, a fifth liquid outlet at the bottom, and a fifth discharge outlet on the side. The fifth feed inlet is connected to the fourth discharge outlet via a sixth pipe, and a fifth valve is provided on the sixth pipe. The fifth liquid outlet at the bottom is connected to the top liquid inlet via a seventh pipe, and a sixth valve is provided on the seventh pipe. The vacuum drying oven includes a sixth inlet, which is connected to the fifth outlet via an eighth pipe; The remelting tank includes a hollow cylindrical third tank body. The third tank body includes a seventh discharge port located on the side and a seventh inlet located at the bottom. The seventh inlet is connected to the remelting outlet through a ninth pipe. The seventh discharge port is connected to the side liquid inlet through a tenth pipe. A seventh valve is provided on the tenth pipe.

2. The system for preparing 5N grade ammonium perrylate according to claim 1, characterized in that, The diameter of the first blade is 1 / 3 of the diameter of the first trough, and the distance between the bottom of the first blade and the bottom of the first trough is 0.3 times the diameter of the first blade.

3. The system for preparing 5N grade ammonium perrylate according to claim 1, characterized in that, The diameter of the second blade is half the diameter of the second channel, and the distance between the bottom of the second blade and the bottom of the second channel is 0.5 times the diameter of the second blade.

4. The system for preparing 5N grade ammonium perrylate according to claim 1, characterized in that, The negatively charged polypiperazine amide type monovalent ion selective nanofiltration membrane is one or more of DK, NF270, ESNA1 or TR-60.

5. A method for preparing 5N grade ammonium perrylate, characterized in that, Applying the system according to any one of claims 1 to 4 includes the following steps: Preparing an ammonium perrylate solution includes providing crude ammonium perrylate, wherein the crude ammonium perrylate is a 2N to 3N grade ammonium perrylate crystal containing impurities such as Si, K, Cu, W, Mo, and Sn; In a dissolving tank, the crude ammonium perrylate is dissolved in ultrapure water and filtered to obtain a crude ammonium perrylate solution. The solution-solid ratio is 2:1 to 6:1, the dissolving temperature is 40℃ to 100℃, the dissolving time is 0.5h to 3h, and the stirring speed is controlled at 100r / min to 200r / min. The preliminary purification process using chemical precipitation includes: pumping the crude ammonium rhenium acid solution into a precipitation reaction tank, adjusting the pH value to 7-11, and adding a precipitant to the precipitation reaction tank to obtain calcium tungstate, calcium molybdate, and calcium stannate precipitates, resulting in a preliminarily purified ammonium rhenium acid solution, which is then stored in a buffer tank. The precipitant is one or more of calcium oxide, calcium hydroxide, and calcium chloride. The amount of precipitant added is 1.2 to 2.5 times the theoretical amount required for the chemical reaction. The reaction temperature is controlled at 40℃ to 100℃, the reaction time is 1 to 3 hours, and the stirring speed is controlled at 50 r / min to 150 r / min. The dual-stage filtration for deep impurity removal includes: the pre-purified ammonium perlite solution is pumped into the dual-stage purification device from the top inlet via a transfer pump, flowing through a liquid flow column. Most of the calcium tungstate, calcium molybdate, and calcium stannate precipitates are retained in the retention chamber. The ammonium perlite solution and a small portion of ionic impurities pass through the primary filtration membrane into the primary permeation chamber. The ammonium perlite solution then passes through a secondary filtration layer to remove high-valence anionic and cationic impurities, resulting in a deeply purified ammonium perlite solution, which is then discharged through the bottom outlet into an ultrasonic freeze crystallization device. The liquid in the retention chamber is returned to the dissolving tank via a discharge pipe. The feed rate is 1 m / s to 5 m / s, and the feed temperature is 20°C to 50°C. Ultrasonic cryo-crystallization includes: pumping the deeply purified ammonium perrylate solution into an ultrasonic cryo-crystallization device; obtaining a mixture of primary crystallizer and water through ultrasonic-temperature coordinated control; separating and drying the mixture by centrifugation to obtain primary crystallization mother liquor and primary crystals; the primary crystallization mother liquor is returned to the top inlet of the dual-stage purification device through a seventh pipe; wherein, the ultrasonic frequency is 20kHz~50kHz, the ultrasonic power is 100W~200W, the cooling equipment is a freezing chamber or a jacketed crystallization tank, the crystallization time is 8h~16h, and the crystallization temperature is -10℃~5℃; Recrystallization includes: dissolving the primary crystal in ultrapure water in a remelting tank to obtain a secondary crystallization mother liquor; introducing the secondary crystallization mother liquor into a primary permeation chamber through a side inlet; purifying it again through a secondary filtration layer to obtain an ammonium peroxide solution; discharging it from the bottom outlet into the ultrasonic freeze crystallization device; and repeating the ultrasonic freeze crystallization and centrifugal separation steps to obtain secondary crystals. Vacuum drying includes: vacuum drying the secondary crystallization to obtain a 5N grade ammonium perrylate product with a purity of 99.999%.

6. The preparation method according to claim 5, characterized in that, The vacuum drying steps include: using a vacuum drying oven as the drying device, controlling the drying temperature at 70℃~110℃, and the drying time at 12h~24h.

7. The preparation method according to claim 5, characterized in that, The liquid-to-solid ratio for re-dissolving in ultrapure water is 2:1 to 6:1, the dissolution temperature is 40℃ to 100℃, and the dissolution time is 0.5h to 3h.

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