Cerium nitrate refining kettle

Abstract

The utility model discloses a cerous nitrate refining kettle which comprises a refining kettle wall, a refining kettle cover, a refining kettle bottom and a refining kettle cavity defined by the refining kettle wall, the refining kettle cover and the refining kettle bottom, the cerous nitrate refining kettle further comprises a stirrer, a stirring shaft of the stirrer penetrates through the refining kettle cover, and a cerous nitrate primary product inlet and a dilute nitric acid inlet are formed in the refining kettle cover. A refined liquid outlet is formed in the refining kettle bottom, a flat membrane is arranged in the refining kettle cavity and divides the refining kettle cavity into an upper refining cavity and a lower refining cavity which are separated from each other, and stirring blades of the stirrer are positioned in the upper refining cavity. The refined cerous nitrate solution formed by the device disclosed by the utility model can be directly used for subsequent production without re-filtration and oil removal or recrystallization.

Description

Technical Field

[0001] The utility model relates to the production of cerium nitrate, and more specifically to a cerium nitrate refining kettle. Background Art

[0002] Cerium ammonium nitrate, with the molecular formula Ce(NH4)2(NO3)6, referred to as CAN, is an orange-red granular crystal that easily dissolves in water and is used as an oxidant.

[0003] In the early days, ammonium cerium nitrate was mainly used in organic synthesis reactions as an organic reaction reagent; in recent years, ammonium cerium nitrate has been widely used in the electronics industry, etc., mainly as a brightener for LEDs, an etchant for integrated circuits, and a special corrosive agent for CDs and liquid crystal displays.

[0004] The rapidly developing electronics industry has higher and higher requirements for CAN quality, and has put forward high requirements on product purity, crystal form, color, and color stability, especially product purity, with the requirement for impurity ions measured in ppm.

[0005] Ce(NO3)3 (cerium nitrate) is an intermediate product of CAN. The TREO (wt% <50) of cerium nitrate commonly sold on the market has a CeO2 / TREO ratio between 99 and 99.9. Before producing ammonium cerium nitrate, the purchased cerium nitrate usually needs to be refined.

[0006] CN110745857A discloses a method for preparing high-purity clean cerium nitrate and a product, comprising the following steps: (1) adding cerium nitrate into nitric acid until the cerium nitrate is completely dissolved to obtain a cerium nitrate solution, and adjusting the pH value of the cerium nitrate solution to 0.8-1; (2) filtering the cerium nitrate solution obtained in step (1) to obtain a filtrate (plate and frame filtration), and removing oil from the filtrate; (3) concentrating the filtrate treated in step (2) at 120-125°C to obtain a supersaturated cerium nitrate solution; (4) crystallizing the supersaturated cerium nitrate solution obtained in step (3) by ultrasonic wave in an ice bath, aging and centrifuging to obtain cerium nitrate crystals; (5) recrystallizing the cerium nitrate crystals obtained in step (4) and centrifuging.

[0007] Although CN110745857A can obtain high-purity and clean cerium nitrate, the process steps of the method are relatively complicated, and each step is an intermittent operation, which cannot form continuous production. Utility Model Content

[0008] In view of the above problems, the utility model provides a cerium nitrate refining kettle. The refined cerium nitrate solution produced by the cerium nitrate refining kettle does not need to be filtered and deoiled again, and does not need to be recrystallized, and can be directly used in subsequent production.

[0009] A cerium nitrate refining kettle comprises a refining kettle wall, a refining kettle cover, a refining kettle bottom and a refining kettle cavity surrounded by the refining kettle wall, the refining kettle cover and the refining kettle bottom. The cerium nitrate refining kettle also comprises a stirrer, the stirring shaft of the stirrer passes through the refining kettle cover, the refining kettle cover is provided with a cerium nitrate primary product inlet and a dilute nitric acid inlet, the refining kettle bottom is provided with a refined liquid outlet, a flat membrane is installed in the refining kettle cavity, the flat membrane divides the refining kettle cavity into two mutually isolated upper refining chambers and a lower refining chamber, and the stirring blades of the stirrer are located in the upper refining chamber.

[0010] Optionally, the flat membrane includes a plurality of flat membrane units and a liquid collecting pipe, the liquid collecting pipe is connected to the refined liquid outlet, each flat membrane unit includes a longitudinal channel, a filter membrane, a liquid collecting chamber and a unit wall, the longitudinal channel is surrounded by the filter membrane, the liquid collecting chamber is surrounded by the filter membrane and the unit wall, and the liquid collecting chamber covers the longitudinal channel; the liquid collecting chamber of each flat membrane unit is connected to the liquid collecting pipe through a pipeline, the upper end of the longitudinal channel of each flat membrane unit is connected to the upper refining chamber, and the lower end is connected to the lower refining chamber; a waste liquid outlet is also provided on the bottom of the refining kettle, and the waste liquid outlet is connected to the lower refining chamber.

[0011] Optionally, the pore size of the filter membrane is <0.1 um.

[0012] Optionally, the flat membrane is a ceramic flat membrane, the cerium nitrate refining kettle is an enamel kettle, and the liquid collecting pipe is a ceramic tube.

[0013] Optionally, a multifunctional plate is further provided in the upper refining chamber, and the multifunctional plate is located above the stirring blades of the stirrer. A plurality of conical protrusions are provided downward on the lower surface of the multifunctional plate, and the farther the conical protrusions are from the lower surface of the multifunctional plate, the smaller their diameters.

[0014] Optionally, a plurality of oil overflow holes are provided on the multifunctional plate.

[0015] Optionally, the diameter of the oil overflow hole gradually decreases from the lower surface to the upper surface of the multifunctional plate.

[0016] Optionally, the diameter of the oil overflow hole on the upper surface of the multifunctional plate is 0.1 mm-1 mm.

[0017] Optionally, the multifunctional board is a ceramic board.

[0018] Compared with the prior art, the beneficial effects of the present invention are:

[0019] The refined cerium nitrate solution formed by the utility model does not need to be filtered and deoiled again, and does not need to be recrystallized, and can be directly used for subsequent production. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0021] Figure 1 This is a schematic diagram of the overall structure of the cerium nitrate refining kettle of the utility model;

[0022] Figure 2 This is the principle structure diagram of the flat membrane unit of the utility model;

[0023] Figure 3 It is a schematic diagram of a top view of the multifunctional board of the utility model;

[0024] Figure 4 It is a schematic diagram of a partial cross-sectional view of the multifunctional board of the utility model;

[0025] Explanation of the reference numerals: 10. Multifunctional plate, 101. Conical protrusion, 102. Oil overflow hole, 103. Oil overflow pipe, 11. Refining kettle wall, 12. Refining kettle cavity, 121. Upper refining chamber, 122. Lower refining chamber, 13. Refining kettle cover, 14. Refining kettle bottom, 15. Agitator, 16. Cerium nitrate primary product inlet, 17. Dilute nitric acid inlet, 18. Refined liquid outlet, 181. Waste liquid outlet, 19. Flat membrane, 191. Longitudinal channel, 192. Filter membrane, 193. Liquid collecting chamber, 194. Unit wall, 195. Liquid collecting pipe. DETAILED DESCRIPTION

[0026] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, or it can be an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0027] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as a limitation on the present invention. In the description of the present invention, "multiple" means two or more, unless otherwise precisely and specifically specified.

[0028] The terms "first", "second", "third", "fourth", etc. (if any) in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein, for example. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0029] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0030] The following specific embodiments are used to describe the technical solution of the utility model in detail. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described in detail in some embodiments.

[0031] Please refer to Figure 1 , Figure 1 It is a schematic diagram of the overall structure of a cerium nitrate refining kettle.

[0032] A cerium nitrate refining kettle comprises a refining kettle wall 11, a refining kettle cover 13, a refining kettle bottom 14 and a refining kettle cavity 12 surrounded by the refining kettle wall 11, the refining kettle cover 13 and the refining kettle bottom 14. The cerium nitrate refining kettle also comprises a stirrer 15, the stirring shaft of the stirrer 15 passes through the refining kettle cover 13, a cerium nitrate primary product inlet 16 and a dilute nitric acid inlet 17 are provided on the refining kettle cover 13, and a refining liquid outlet 18 is provided on the refining kettle bottom 14.

[0033] A flat membrane 19 is installed at the lower part of the refining kettle chamber 12. The flat membrane 19 divides the refining kettle chamber 12 into two mutually isolated upper refining chambers 121 and lower refining chambers 122. The stirring blades of the agitator 15 are located in the upper refining chamber 121. The flat membrane 19 includes a plurality of flat membrane units and a liquid collecting pipe 195. The liquid collecting pipe 195 is connected to the refined liquid outlet 18.

[0034] Please refer to Figure 2 , Figure 2 This is the principle structure diagram of the flat membrane unit.

[0035] Each flat membrane unit includes a longitudinal channel 191, a filter membrane 192, a liquid collecting chamber 193 and a unit wall 194. The longitudinal channel 191 is surrounded by the filter membrane 192, the liquid collecting chamber 193 is surrounded by the filter membrane 192 and the unit wall 194, and the liquid collecting chamber 193 covers the longitudinal channel 191.

[0036] The liquid collecting chamber 193 of each flat membrane unit is connected to the liquid collecting pipe 195 through a pipeline, and the upper end of the longitudinal channel 191 of each flat membrane unit is connected to the upper refining chamber 121, and the lower end is connected to the lower refining chamber 122.

[0037] A waste liquid outlet 181 is also provided on the bottom 14 of the refining kettle, and the waste liquid outlet 181 is communicated with the lower refining chamber 122 .

[0038] When cerium nitrate is refined, colorless granular cerium nitrate primary product enters the cerium nitrate refining kettle from the cerium nitrate primary product inlet 16, and at the same time, dilute nitric acid enters the cerium nitrate refining kettle from the dilute nitric acid inlet 17. The cerium nitrate primary product is dissolved in the dilute nitric acid under the stirring of the stirrer 15, and then enters the longitudinal channel 191 for filtration under the action of gravity. The cerium nitrate dissolved in the dilute nitric acid and the dilute nitric acid enter the liquid collecting chamber 193 through the filter membrane 192 and then enter the liquid collecting pipe 195, and then flow out from the refined liquid outlet 18. The impurities and other concentrated liquid that have not flowed into the liquid collecting chamber 193 enter the lower refining chamber 122 and are finally discharged from the waste liquid outlet 181.

[0039] Continuous operation can be achieved by controlling the intake of primary cerium nitrate, dilute nitric acid and refined liquid. Since the refined liquid keeps flowing out during the refining process, a suction effect is formed on the liquid collecting chamber 193, which generates a suction force on the liquid passing through the longitudinal channel 191, so that the solution enters the liquid collecting chamber 193 through the filter membrane.

[0040] The liquid discharged from the waste liquid outlet 181 can be collected and used as an intermediate product in a production process with lower requirements, or it can be returned to the upper refining chamber 121 for further dissolution and filtration.

[0041] Furthermore, in order to avoid the introduction of metal impurities, the flat membrane 19 is a ceramic flat membrane, the cerium nitrate refining kettle is an enamel kettle, and the liquid collecting pipe 195 is a ceramic tube.

[0042] Furthermore, the pore size of the filter membrane 192 is less than 0.1 um.

[0043] Furthermore, in order to increase the pressure difference of filtration, the pipeline of the refined liquid outlet 18 can also be connected to a liquid pump (not shown in the figure); those skilled in the art should understand that the liquid pump needs to be installed only when the process capacity cannot operate normally. When the process capacity can operate, that is, when the liquid pump is not installed, and the pressure difference of filtration can be used for normal filtration, the liquid pump is not installed to avoid the introduction of metal impurities.

[0044] Further, please refer again to Figure 1 , and references Figure 3-Figure 4 , Figure 3 This is a top view of the multi-function board. Figure 4 This is a partial cross-sectional view of the multi-function board.

[0045] A multifunctional plate 10 is also provided in the upper refining chamber 121. The multifunctional plate 10 is located above the stirring blade of the stirrer 15. When working, the lower surface of the multifunctional plate 10 is located below the dissolved liquid level line, and the upper surface is flush with the liquid level line or slightly lower than the liquid level line. The multifunctional plate 10 is provided with a hole for allowing the stirring shaft of the stirrer 15 to pass through, a hole for allowing the cerium nitrate primary product feed pipe installed on the cerium nitrate primary product inlet 16 to pass through, and a hole for allowing the dilute nitric acid feed pipe installed on the dilute nitric acid inlet 17 to pass through. A plurality of conical protrusions 101 are downwardly provided on the lower surface of the multifunctional plate 10. The farther the conical protrusion 101 is from the lower surface of the multifunctional plate 10, the smaller the diameter. With the provision of the plurality of conical protrusions 101, on the one hand, the foam generated by the dissolving and stirring gradually moves upward to the liquid surface because it is lighter than the liquid. On the one hand, the foam continuously rubs against the conical protrusion 101 to accelerate the rupture of the foam. On the other hand, the top directly pierces the foam or the macromolecular oil layer, while promoting gas-liquid separation, reducing the foam, and generating a downward force. Compared with the production without the multifunctional plate 10 , the foam in the cerium nitrate refining kettle installed with the multifunctional plate 10 is reduced by about 20%.

[0046] Furthermore, a plurality of oil overflow holes 102 are provided on the multifunctional board 10. During the production process, impure oil molecule clusters gradually float up to the multifunctional board 10. When contacting with the conical protrusions 101, the impurity oil molecule clusters are punctured into small molecules and gathered at the multifunctional board 10. They overflow from the oil overflow holes 102 to the top of the multifunctional board 10 and are discharged through the oil overflow pipe 103. In addition, after the oil overflow holes 102 are set, the foam is further broken by the collision of the oil overflow holes 102, thereby further reducing the foam.

[0047] Furthermore, in order to achieve a better oil-liquid separation effect, the diameter of the oil overflow hole 102 gradually decreases from the lower surface to the upper surface of the multi-function plate 10 .

[0048] Furthermore, the multifunctional board 10 is a ceramic board, and the diameter of the oil overflow hole 102 on the upper surface of the multifunctional board 10 is 0.1 mm-1 mm.

[0049] The elimination and separation of foam and oil molecules make the mixing uniformity effect better, and the liquid entering the flat membrane 19 below is more uniform, thereby improving the purity of the refined liquid.

[0050] When the multifunctional board 10 is installed, the groove (not shown in the figure) on the lower surface of the multifunctional board 10 is embedded into the installation block (not shown in the figure) on the refining kettle wall 11.

[0051] During maintenance, cleaning water can be introduced into the cerium nitrate refining kettle from the cerium nitrate primary product inlet 16 and the waste liquid outlet 181 respectively to remove impurities in the flat membrane 19 and other cerium nitrate refining kettles.

[0052] The refined cerium nitrate solution formed by the cerium nitrate refining kettle of the utility model does not need to be filtered and deoiled again, and does not need to be recrystallized, and can be directly used for subsequent production. Compared with CN110745857A, the process and equipment are relatively simple, and continuous production can be achieved without the introduction of metal impurities.

[0053] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model, rather than to limit it. Although the utility model has been described in detail with reference to the aforementioned embodiments, ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not make the essence of the corresponding technical solution deviate from the scope of the technical solution of the embodiments of the utility model.

Claims

1. A cerium nitrate refining kettle, comprising a refining kettle wall (11), a refining kettle cover (13), a refining kettle bottom (14) and a refining kettle chamber (12) surrounded by the refining kettle wall (11), the refining kettle cover (13) and the refining kettle bottom (14), the cerium nitrate refining kettle also comprising a stirrer (15), the stirring shaft of the stirrer (15) passing through the refining kettle cover (13), the refining kettle cover (13) is provided with a cerium nitrate primary product inlet (16) and a dilute nitric acid inlet (17), the refining kettle bottom (14) is provided with a refining liquid outlet (18), characterized in that: The refining kettle chamber (12) is provided with a flat membrane (19), which divides the refining kettle chamber (12) into two mutually isolated upper refining chambers (121) and lower refining chambers (122), and the stirring blades of the stirrer (15) are located in the upper refining chamber (121).

2. The cerium nitrate refining kettle according to claim 1, characterized in that: The flat membrane (19) comprises a plurality of flat membrane units and a liquid collecting pipe (195). The liquid collecting pipe (195) is connected to the refined liquid outlet (18). Each flat membrane unit comprises a longitudinal channel (191), a filter membrane (192), a liquid collecting chamber (193) and a unit wall (194). The longitudinal channel (191) is surrounded by the filter membrane (192), the liquid collecting chamber (193) is surrounded by the filter membrane (192) and the unit wall (194), and the liquid collecting chamber (193) is surrounded by the filter membrane (192) and the unit wall (194). The liquid cavity (193) covers the longitudinal channel (191) therein; the liquid collecting cavity (193) of each flat membrane unit is connected to the liquid collecting pipe (195) through a pipeline; the upper end of the longitudinal channel (191) of each flat membrane unit is connected to the upper refining cavity (121), and the lower end is connected to the lower refining cavity (122); a waste liquid outlet (181) is also provided on the bottom (14) of the refining kettle, and the waste liquid outlet (181) is connected to the lower refining cavity (122).

3. The cerium nitrate refining kettle according to claim 2, characterized in that: The pore size of the filter membrane (192) is less than 0.1 um.

4. The cerium nitrate refining kettle according to claim 1, characterized in that: The flat membrane (19) is a ceramic flat membrane, the cerium nitrate refining kettle is an enamel kettle, and the liquid collecting pipe (195) is a ceramic pipe.

5. The cerium nitrate refining kettle according to any one of claims 1 to 4, characterized in that: A multifunctional plate (10) is also provided in the upper refining chamber (121). The multifunctional plate (10) is located above the stirring blade of the stirrer (15). A plurality of conical protrusions (101) are provided downward on the lower surface of the multifunctional plate (10). The farther the conical protrusions (101) are from the lower surface of the multifunctional plate (10), the smaller their diameters.

6. The cerium nitrate refining kettle according to claim 5, characterized in that: The multifunctional plate (10) is provided with a plurality of oil overflow holes (102).

7. The cerium nitrate refining kettle according to claim 6, characterized in that: The diameter of the oil overflow hole (102) gradually decreases from the lower surface to the upper surface of the multifunctional plate (10).

8. The cerium nitrate refining kettle according to claim 7, characterized in that: The oil overflow hole (102) has a hole diameter of 0.1 mm to 1 mm on the upper surface of the multifunctional plate (10).

9. The cerium nitrate refining kettle according to claim 6, characterized in that: The multifunctional board (10) is a ceramic board.

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