Fluidized bed reactor for purification and microcrystalline graphite fluidized bed continuous purification system

Abstract

The utility model discloses a fluidized bed reactor for purification and a microcrystalline graphite fluidized bed continuous purification system. The fluidized bed reactor for purification comprises a reactor main body, a reaction chamber is arranged in the reactor main body, the reaction chamber is provided with a gas dispersion area, a reaction area and a settlement area which are communicated in sequence, the reactor main body is further provided with a gas inlet structure, a gas outlet structure, a feeding structure and a discharging structure, the gas inlet structure is directly communicated with the gas dispersion area, and the gas outlet structure is directly communicated with the reaction area. The gas outlet structure is directly communicated with the settling area, and the feeding structure and the discharging structure are directly communicated with the reaction area; the distribution plate structure is arranged in the reaction chamber, the distribution plate structure is at least used for bearing microcrystalline graphite, and the distribution plate structure is further provided with a ventilation structure through which gas can pass. On one hand, high-purity carbon material preparation is realized; on the other hand, a large amount of acid-containing wastewater is not generated, high-temperature treatment at 3000 DEG C is not needed, and the cost is low.

Description

Technical Field

[0001] The utility model particularly relates to a fluidized bed reactor for purification and a microcrystalline graphite fluidized bed continuous purification system, belonging to the technical field of material purification. Background Art

[0002] Battery materials require very high purity of graphite raw materials, with the Fe impurity content even required to be below 30ppm. However, natural graphite is derived from natural ores and has a complex impurity composition and structure, especially microcrystalline graphite.

[0003] The current industrial treatment methods mainly include pickling purification and high-temperature evaporation. However, pickling purification generally uses HF acid for purification, which produces a large amount of acid-containing wastewater, causing environmental pollution. High-temperature evaporation requires the use of an intermittent furnace at approximately 3000°C for purification. This treatment process has a small processing capacity and requires intermittent operation, which has high costs and is difficult to commercialize on a large scale. Summary of the Invention

[0004] The main purpose of the utility model is to provide a fluidized bed reactor for purification and a microcrystalline graphite fluidized bed continuous purification system, which can realize the preparation of high-purity carbon materials (>99.95%) on the one hand; on the other hand, the system does not produce a large amount of acid-containing wastewater, does not require high-temperature intermittent treatment at 3000°C, has low cost and is easy to industrialize.

[0005] In order to achieve the above-mentioned purpose of the utility model, the technical solutions adopted by the utility model include:

[0006] A first aspect of an embodiment of the present invention provides a fluidized bed reactor for purification, comprising:

[0007] A reactor body, wherein the reactor body has a reaction chamber therein, the reaction chamber having a gas dispersion zone, a reaction zone, and a settling zone connected in sequence, the reactor body further being provided with an air inlet structure, an air outlet structure, a feed structure, and a discharge structure, the air inlet structure being directly connected to the gas dispersion zone, the air outlet structure being directly connected to the settling zone, and the feed structure and the discharge structure being directly connected to the reaction zone;

[0008] A distribution plate structure is arranged in the reaction chamber, and the distribution plate structure is located between the gas dispersion zone and the reaction zone, or the distribution plate structure is arranged between the gas dispersion zone and the reaction zone and in the dispersion zone. The distribution plate structure is at least used to carry solid materials, and the distribution plate structure also has a breathable structure for gas to pass through.

[0009] A second aspect of the embodiment of the present invention provides a microcrystalline graphite fluidized bed continuous purification system, comprising:

[0010] A reaction unit, comprising the fluidized bed reactor for purification, wherein the fluidized bed reactor for purification is used to purify the microcrystalline graphite;

[0011] a feeding unit connected to the feeding structure of the fluidized bed reactor for purification and used to provide microcrystalline graphite into the fluidized bed reactor for purification;

[0012] a receiving unit connected to the discharge structure of the purification fluidized bed reactor and used to receive the graphite treated by the purification fluidized bed reactor;

[0013] a gas supply unit connected to the gas inlet structure of the purification fluidized bed reactor and used to input fluidizing gas or reaction gas into the purification fluidized bed reactor;

[0014] The tail gas treatment unit is connected to the gas outlet structure of the purification fluidized bed reactor and is used to purify the gas output from the purification fluidized bed reactor.

[0015] Compared with the existing technology, the advantages of the present invention include: the embodiment of the present invention provides a fluidized bed reactor for purification and a microcrystalline graphite fluidized bed continuous purification system, which, on the one hand, realizes the preparation of high-purity carbon materials (>99.95%); on the other hand, does not produce a large amount of acid-containing wastewater; more importantly, the fluidized bed continuous purification system can realize continuous low-temperature production, does not require 3000°C high-temperature intermittent treatment, and has the advantages of low cost and easy industrialization. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments recorded in this application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 This is a schematic structural diagram of a microcrystalline graphite fluidized bed continuous purification system provided in a typical embodiment of the present invention;

[0018] Figure 2 This is a schematic structural diagram of a fluidized bed reactor for purification provided in a typical embodiment of the present invention;

[0019] Figure 3 This is a schematic diagram of the partial structure of a reactor body provided in a typical embodiment of the present invention;

[0020] Figure 4This is a partial structural diagram of another reactor body provided in a typical embodiment of the present invention;

[0021] Figure 5 This is a partial structural diagram of another reactor body provided in a typical embodiment of the present invention;

[0022] Figure 6 This is a schematic diagram of the partial structure of another reactor body provided in a typical implementation case of the present utility model. DETAILED DESCRIPTION

[0023] In view of the shortcomings of the existing technology, the inventors of this case, after long-term research and extensive practice, have proposed the technical solution of this utility model. The following will further explain this technical solution, its implementation process and principles.

[0024] The present invention provides a fluidized bed reactor for purification, comprising:

[0025] A reactor body, wherein the reactor body has a reaction chamber therein, the reaction chamber having a gas dispersion zone, a reaction zone, and a settling zone connected in sequence, the reactor body further being provided with an air inlet structure, an air outlet structure, a feed structure, and a discharge structure, the air inlet structure being directly connected to the gas dispersion zone, the air outlet structure being directly connected to the settling zone, and the feed structure and the discharge structure being directly connected to the reaction zone;

[0026] A distribution plate structure is arranged in the reaction chamber, and the distribution plate structure is located between the gas dispersion zone and the reaction zone, or the distribution plate structure is arranged between the gas dispersion zone and the reaction zone and in the dispersion zone. The distribution plate structure is at least used to carry solid materials, and the distribution plate structure also has a breathable structure for gas to pass through.

[0027] Furthermore, the distribution plate structure includes at least one distribution plate with a gas-permeable structure, and at least one of the distribution plates is located between the gas dispersion zone and the reaction zone, and isolates the gas dispersion zone and the reaction zone from each other.

[0028] Furthermore, the distribution plate structure includes m distribution plates with a breathable structure, and the m distribution plates are arranged in sequence along the direction from the gas dispersion zone to the sedimentation zone. The m distribution plates divide the reaction zone into m interconnected reaction spaces, wherein the first distribution plate is located between the gas dispersion zone and the reaction zone, and isolates the gas dispersion zone from the reaction zone. The gas enters the reaction zone through the first distribution plate, and passes through the second distribution plate from bottom to top...the mth distribution plate, m≥2.

[0029] Furthermore, there is a gap between the second to mth distribution plates and the side walls of the reaction chamber, and adjacent reaction spaces are directly connected via the gaps between the distribution plates and the side walls of the reaction chamber. The gaps between the second to mth distribution plates and the side walls of the reaction chamber are connected and form solid material channels through which solid materials can pass. Of course, the solid material channels can also allow gas to pass through.

[0030] Furthermore, the plurality of distribution plates except the first distribution plate are staggeredly arranged along the direction from the gas dispersion zone to the sedimentation zone.

[0031] Furthermore, the area of the first distribution plate is equal to the radial area of the reaction chamber corresponding to its position, and the area of the second to mth distribution plates is smaller than the radial area of the reaction chamber corresponding to its position.

[0032] Furthermore, baffles are provided on the second to mth distribution plates, and the baffles are arranged at an angle to the distribution plates, and the baffles and the distribution plates enclose a receiving space for receiving solid materials.

[0033] Furthermore, the air intake structure includes one or more air intake ports.

[0034] Furthermore, the air outlet structure includes one or more air outlets.

[0035] Furthermore, the reaction zone is a straight cylindrical structure with a uniform radial cross-sectional area, or the reaction zone is a conical structure with a radial cross-sectional area gradually increasing toward the sedimentation zone.

[0036] A second aspect of the embodiment of the present invention provides a microcrystalline graphite fluidized bed continuous purification system, comprising:

[0037] A reaction unit, comprising the fluidized bed reactor for purification, wherein the fluidized bed reactor for purification is used to purify the microcrystalline graphite;

[0038] a feeding unit connected to the feeding structure of the fluidized bed reactor for purification and used to provide microcrystalline graphite into the fluidized bed reactor for purification;

[0039] a receiving unit connected to the discharge structure of the purification fluidized bed reactor and used to receive the graphite treated by the purification fluidized bed reactor;

[0040] a gas supply unit connected to the gas inlet structure of the purification fluidized bed reactor and used to input fluidizing gas or reaction gas into the purification fluidized bed reactor;

[0041] The tail gas treatment unit is connected to the gas outlet structure of the purification fluidized bed reactor and is used to purify the gas output from the purification fluidized bed reactor.

[0042] Furthermore, the tail gas treatment unit includes a cyclone separator, a metal halide collector and an absorption tower connected in series, and the cyclone separator is directly connected to the fluidized bed reactor for purification.

[0043] The technical solution, its implementation process and principles will be further explained below in conjunction with the accompanying drawings and specific embodiments. Unless otherwise specified, the intermediate tank, feed tank and receiving tank and other containers, as well as the cooling furnace, pre-oxidation furnace, desorption furnace, etc. used in the embodiments of the present invention are all known in the art. The cyclone separator, metal halide compound collector and absorption tower used in the embodiments of the present invention are also known in the art, and no specific equipment models are limited here. The gas supply mechanism used in the embodiments of the present invention and the connection structure between the various functional mechanisms are all known in the art and are not specifically limited here.

[0044] Example 1

[0045] See also Figure 1 A continuous purification system for microcrystalline graphite in a fluidized bed includes a reaction unit 200 and a feeding unit 100, a receiving unit 300, a gas supply unit and an exhaust gas treatment unit 400 respectively connected to the reaction unit 200, wherein the feeding unit 100 is used to transport the microcrystalline graphite into the reaction unit 200, and the gas supply unit is used to input fluidizing gas into the reaction unit 200. The fluidizing gas or the reaction gas contacts the microcrystalline graphite in the reaction unit 200, and the microcrystalline graphite is purified. The purified microcrystalline graphite enters the receiving unit 300 for storage, and the gas in the reaction unit 200 enters the exhaust gas treatment unit 400 for purification and then is discharged or collected. Exemplarily, the fluidizing gas can be a mixture of an inert gas such as nitrogen, argon and a halogen gas such as chlorine, fluorine, hydrogen chloride, and Freon, and the reaction gas can be a halogen gas such as chlorine, fluorine, hydrogen chloride, and Freon. Of course, in addition to being used for the purification of microcrystalline graphite, this embodiment can also be used for the purification of other natural graphite, biochar, coal, etc.

[0046] In this embodiment, please refer to Figure 2The reaction unit 200 includes a fluidized bed reactor for purification, which is used to purify the microcrystalline graphite (it can be understood that the purification process is achieved together with the fluidizing gas provided by the gas supply unit). The fluidized bed reactor for purification includes a reactor body and a distribution plate structure. The reactor body has a reaction chamber inside, and the reaction chamber has a gas dispersion zone 213, a reaction zone 212 and a sedimentation zone 211 connected in sequence. The reactor body is also provided with an air inlet structure 214, an air outlet structure 215, a feed structure 216 and a discharge structure 217. The air inlet structure 214 is directly connected to the gas dispersion zone 213. The gas outlet structure 215 is directly connected to the sedimentation zone 211, the feed structure 216 and the discharge structure 217 are directly connected to the reaction zone 212, and the distribution plate structure is arranged in the reaction chamber. The distribution plate structure is located between the gas dispersion zone 213 and the reaction zone 212. The distribution plate structure is at least used to support microcrystalline graphite, and the distribution plate structure also has a breathable structure for gas to pass through, wherein the feed unit 100, the receiving unit 300, the gas supply unit, and the tail gas treatment unit 400 are respectively connected to the feed structure 216, the discharge structure 217, the gas intake structure 214, and the gas outlet structure 215 of the reactor body.

[0047] In this embodiment, before the purification treatment is carried out, the discharge structure 217 of the reactor body is closed, and the feeding structure 216, the air inlet structure 214 and the air outlet structure 215 are opened. The fluidizing gas enters the gas dispersion zone 213 of the reactor through the air inlet structure 214, and the microcrystalline graphite enters the reaction zone 212 of the reactor from the feeding unit 100 through the feeding structure 216 and presents a fluidized boiling state under the action of the fluidizing gas (if the flow rate of the fluidizing gas is small, the microcrystalline graphite will accumulate on the distribution plate; if the flow rate of the fluidizing gas reaches the predetermined requirement, the microcrystalline graphite will present a fluidized boiling state). After the feeding is completed, the feeding structure 216 is closed, and the fluidizing gas contacts the microcrystalline graphite to realize the purification treatment of the microcrystalline graphite. The fluidizing gas after the purification treatment enters the tail gas treatment unit 400 through the air outlet structure 215 for purification treatment. The microcrystalline graphite after the purification treatment enters the receiving unit 300 through the discharge structure 217, thereby completing the purification of the microcrystalline graphite.

[0048] It should be noted that the air intake structure 214, the air outlet structure 215, the feed structure 216 and the discharge structure 217 are all equipped with switchable valves. Of course, these valves can also be set on the connecting pipelines between the feed unit 100, the receiving unit 300, the gas supply unit, the exhaust gas treatment unit 400 and the feed structure 216, the discharge structure 217, the air intake structure 214, and the air outlet structure 215.

[0049] In this embodiment, please refer to Figure 3 and Figure 4 The reaction zone 212 is a straight cylindrical structure with a uniform radial cross-sectional area or the reaction zone 212 is a tapered structure with a radial cross-sectional area gradually increasing in the direction toward the sedimentation zone 211. The straight cylindrical structure can provide a larger volume of effective reaction zone 212, while the tapered structure can increase the flow rate of the fluidizing gas in the reaction zone 212, reduce the dead zone, and improve the purification effect. In this embodiment, the sedimentation zone 211 includes a first sedimentation section and a second sedimentation section arranged in sequence away from the reaction zone 212. The area of the radial cross-section of the first sedimentation section gradually increases in the direction away from the reaction zone 212, and the area of the radial cross-section of the second sedimentation section is uniform and the same as the maximum radial cross-sectional area of the first sedimentation section. Through such a design, the fine powder in the fluidizing gas after the reaction can be fully settled.

[0050] In a more typical implementation scheme, please refer to Figure 5 and Figure 6 The distribution plate structure includes m distribution plates 210 with a gas permeable structure, and the m distribution plates 210 are sequentially spaced along the direction from the gas dispersion zone 213 to the sedimentation zone 211. The m distribution plates 210 divide the reaction zone 212 into m interconnected reaction spaces, wherein the first distribution plate 210 is located between the gas dispersion zone 213 and the reaction zone 212, and isolates the gas dispersion zone 213 from the reaction zone 212, m≥2, wherein there is a gap between the second distribution plate 210 to the mth distribution plate 210 and the side wall of the reaction chamber, and adjacent reaction spaces are directly connected via the gap between the distribution plate 210 and the side wall of the reaction chamber, and the second distribution plate 210 to the mth distribution plate 21 0 is connected to the gap between the sidewalls of the reaction chamber, forming a channel for both solid material and gas to pass through. Furthermore, baffles 218 are provided on the second through mth distribution plates 210. These baffles 218 are arranged at an angle to the distribution plates 210, and the space between the baffles 218 and the distribution plates 210 forms a storage space for microcrystalline graphite. By providing m distribution plates 210, the reaction zone 212 is divided into multiple storage spaces, which increases the residence time of the fluidizing gas within the reaction zone 212 and thereby improves the purification effect. Furthermore, the m distribution plates 210 divide the reaction zone 212 into multiple storage spaces, reducing the height of each storage space for the purification reaction. The low bed height further enhances the stability of the fluidization reaction. It will be appreciated that the multiple distribution plates 210, excluding the first distribution plate 210, are staggered in a direction from the gas dispersion zone 213 toward the settling zone 211.

[0051] In this embodiment, please refer to Figure 1The feeding unit 100 may include at least one intermediate tank 110 and at least one feeding tank 120 connected in series. The feeding tank 120 is directly connected to the feeding structure 216 of the fluidized bed reactor for purification. The receiving unit 300 includes at least one receiving tank 310. The receiving tank 310 is connected to the discharge structure 217 of the fluidized bed reactor for purification. The gas supply unit may include a fluidized gas storage tank and an air pump. The fluidized gas storage tank is connected to the fluidized bed reactor for purification via the air pump. The air pump can adjust the pressure and flow rate of the fluidized gas. The tail gas treatment unit 400 includes a cyclone separator 410, a metal halide compound collector 420, and an absorption tower 430 connected in series. The cyclone separator 410 is directly connected to the fluidized bed reactor for purification. The cyclone separator 410 is used to separate a small amount of dust contained in the gas, and the metal halide compound collector 420 is used to separate metal salt substances in the gas.

[0052] Exemplarily, the process of treating natural graphite using a microcrystalline graphite fluidized bed continuous purification system in this embodiment includes the following steps:

[0053] Pre-purification: using hydrochloric acid, nitric acid, hydrofluoric acid or sulfuric acid to acid-immerse the graphite raw material to obtain a pre-purified dispersion Y1; specifically, the process may include: (1) mixing microcrystalline graphite, pure water and acid (at least one of hydrochloric acid, nitric acid, hydrofluoric acid and sulfuric acid); (2) soaking at 60-90°C for 2-24 hours; (3) performing liquid-solid separation by pressure filtration or high-speed centrifugation, rinsing with water to obtain a filter cake; (3) mixing the filter cake with pure water to obtain a dispersion Y1;

[0054] Drying and granulation: spray drying Y1 to obtain graphite particles Y2 having a moisture content of <5% and a particle size of 8 to 200 μm. Specifically, spray granulation can be performed at 80 to 350° C. and spray drying to obtain powder Y2 having a moisture content of <5% and a particle size of 8 to 200 μm. The Y2 particles have characteristics suitable for fluidization. It should be noted that spray drying to obtain graphite particles suitable for fluidization is a known technique in the art and is not limited thereto.

[0055] Continuous chlorination purification: Y2 is added to the fluidized bed reactor for purification and halogen gas is introduced to achieve good fluidization and continuous production to obtain high-purity microcrystalline graphite materials.

[0056] It should be understood that the above embodiments are merely illustrative of the technical concepts and features of the present invention. Their purpose is to enable those familiar with the art to understand the contents of the present invention and implement them accordingly. They are not intended to limit the scope of protection of the present invention. Any equivalent changes or modifications based on the spirit of the present invention are intended to fall within the scope of protection of the present invention.

Claims

1. A fluidized bed reactor for purification, characterized in that: include: A reactor body, wherein the reactor body has a reaction chamber therein, the reaction chamber having a gas dispersion zone, a reaction zone, and a settling zone connected in sequence, the reactor body further being provided with an air inlet structure, an air outlet structure, a feed structure, and a discharge structure, the air inlet structure being directly connected to the gas dispersion zone, the air outlet structure being directly connected to the settling zone, and the feed structure and the discharge structure being directly connected to the reaction zone; A distribution plate structure is arranged in the reaction chamber, and the distribution plate structure is located between the gas dispersion zone and the reaction zone, or the distribution plate structure is arranged between the gas dispersion zone and the reaction zone and in the dispersion zone. The distribution plate structure is at least used to carry solid materials, and the distribution plate structure also has a breathable structure for gas to pass through.

2. The fluidized bed reactor for purification according to claim 1, wherein: The distribution plate structure includes at least one distribution plate with a gas permeable structure. The at least one distribution plate is located between the gas dispersion zone and the reaction zone, and isolates the gas dispersion zone and the reaction zone from each other.

3. The fluidized bed reactor for purification according to claim 2, wherein: The distribution plate structure includes m distribution plates with a breathable structure, and the m distribution plates are arranged in sequence along the direction from the gas dispersion zone to the sedimentation zone. The m distribution plates divide the reaction zone into m interconnected reaction spaces, wherein the first distribution plate is located between the gas dispersion zone and the reaction zone, and m≥2.

4. The fluidized bed reactor for purification according to claim 3, wherein: There is a gap between the second to mth distribution plates and the side walls of the reaction chamber, and adjacent reaction spaces are directly connected via the gaps between the distribution plates and the side walls of the reaction chamber. The gaps between the second to mth distribution plates and the side walls of the reaction chamber are connected and form solid material channels for solid materials to pass through.

5. The fluidized bed reactor for purification according to claim 4, characterized in that: The plurality of distribution plates except the first distribution plate are staggeredly arranged along a direction from the gas dispersion zone to the sedimentation zone.

6. The fluidized bed reactor for purification according to claim 5, characterized in that: The area of the first distribution plate is equal to the radial area of the reaction chamber corresponding to its position, and the area of the second to mth distribution plates is smaller than the radial area of the reaction chamber corresponding to its position.

7. The fluidized bed reactor for purification according to claim 3, 4, 5 or 6, characterized in that: Baffles are further provided on the second to mth distribution plates. The baffles are arranged at an angle to the distribution plates. The baffles and the distribution plates enclose a containing space for containing solid materials.

8. The fluidized bed reactor for purification according to claim 3, 4, 5 or 6, characterized in that: The air inlet structure includes one or more air inlets, and / or the air outlet structure includes one or more air outlets.

9. The fluidized bed reactor for purification according to claim 1, characterized in that: The reaction zone is a straight cylindrical structure with a uniform radial cross-sectional area, or the reaction zone is a conical structure with a radial cross-sectional area gradually increasing toward the sedimentation zone.

10. A microcrystalline graphite fluidized bed continuous purification system, characterized in that: include: A reaction unit comprising a fluidized bed reactor for purification according to any one of claims 1 to 9, wherein the fluidized bed reactor for purification is used for purifying microcrystalline graphite; a feeding unit connected to the feeding structure of the fluidized bed reactor for purification and used to provide microcrystalline graphite into the fluidized bed reactor for purification; a receiving unit connected to the discharge structure of the purification fluidized bed reactor and used to receive the graphite treated by the purification fluidized bed reactor; a gas supply unit connected to the gas inlet structure of the purification fluidized bed reactor and used to input fluidizing gas or reaction gas into the purification fluidized bed reactor; The tail gas treatment unit is connected to the gas outlet structure of the purification fluidized bed reactor and is used to purify the gas output from the purification fluidized bed reactor.

11. The microcrystalline graphite fluidized bed continuous purification system according to claim 10, characterized in that: The tail gas treatment unit comprises a cyclone separator, a metal halide compound collector and an absorption tower which are connected in series in sequence. The cyclone separator is directly connected to the fluidized bed reactor for purification.

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