Powder preparation and enrichment mechanism, agitator, reactor and powder preparation method

Abstract

The present invention relates to the field of preparation of powder materials, and discloses a powder preparation enrichment mechanism, a stirrer, a reactor and a powder preparation method. The powder preparation enrichment mechanism disclosed in the present invention comprises an enrichment container, wherein a centrifugal impeller arranged vertically with a central axis is arranged in the enrichment container, an enrichment suction port is arranged at a position corresponding to the suction port of the centrifugal impeller, a first filter structure is arranged on the side wall of the enrichment container corresponding to the centrifugal direction of the circumference of the centrifugal impeller, the pore size of the first filter structure is smaller than the particle size of the target product and larger than the particle size of the inhaled reactant, and an enrichment tank is arranged at the lower part of the enrichment container corresponding to the first filter structure. The powder preparation enrichment mechanism of the present application is used to prepare powder, which can realize the continuous separation of reactants and products, improve the reaction rate and shorten the reaction time.

Description

Technical Field

[0001] The invention relates to the field of powder material preparation, in particular to a powder preparation and enrichment mechanism, a stirrer, a reaction kettle and a powder preparation method. Background Art

[0002] In recent years, with the widespread application of powder materials in different fields, the synthesis and preparation of powders have developed over the years, and the preparation and synthesis methods have become diverse.

[0003] At present, the synthesis and preparation methods of powders have become more diverse as the demand increases. Specific methods include ① roasting and decomposition method: using a rotary furnace or rotary kiln to pyrolyze block raw materials or coarse granular raw materials to obtain fine powder materials, which has problems such as low efficiency, easy agglomeration, and the need for secondary treatment; ② mechanical ball milling method: using grinding equipment to grind block raw materials or coarse granular raw materials into fine powder materials, which is only applicable to some materials with low hardness. For some super-hard and difficult-to-grind materials such as corundum, this solution has certain difficulties.

[0004] There are also more common methods such as ③ synthesis method and ④ deposition method, which are to add a variety of reaction materials in a closed reactor, set temperature, pressure, atmosphere and other conditions before fully reacting, and finally take complex steps such as unloading, solid-liquid filtration separation, drying, and crushing to obtain the target product. In this process, the process is long and the preparation rate is slow. The process is intermittent operation, and the reactants and products cannot be separated continuously, which affects the preparation efficiency and increases the production cost of the enterprise.

[0005] It can be seen that the preparation of powder by synthesis method and precipitation method has problems such as low preparation rate and difficulty in continuous separation. Therefore, it is of great significance to improve the equipment and method for preparing powder materials. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a powder preparation and enrichment mechanism, a stirrer, a reactor and a powder preparation method to achieve continuous separation of reactants and products.

[0007] The powder preparation and enrichment mechanism disclosed in the present invention comprises an enrichment container, wherein a centrifugal impeller arranged vertically with a central axis is arranged in the enrichment container, an enrichment suction port is arranged at a position corresponding to the suction port of the centrifugal impeller in the enrichment container, a first filtering structure is arranged on the side wall of the enrichment container corresponding to the centrifugal direction of the circumference of the centrifugal impeller, the pore size of the first filtering structure is smaller than the particle size of the target product and larger than the particle size of the inhaled reactant, and an enrichment tank is arranged at the lower part of the enrichment container corresponding to the first filtering structure.

[0008] Preferably, the enrichment suction port is provided with a second filter structure, and the pore size of the second filter structure is larger than the diameter of the target product.

[0009] Preferably, a single centrifugal impeller is provided in a single enrichment container, the centrifugal impeller is located in the middle of the enrichment container, and the enrichment suction port is located in the middle of the top surface or the middle of the bottom surface of the enrichment container.

[0010] Preferably, the bottom and surrounding of the bottom of the enrichment tank adopt a closed structure or a first filtering structure.

[0011] The stirrer disclosed in the present application comprises a stirring rod and a stirring paddle connected to the stirring rod, and the stirring paddle adopts the powder preparation and enrichment mechanism.

[0012] Preferably, the enrichment suction port is arranged on a side of the enrichment container away from the stirring rod and is located on the rotation center axis of the stirring paddle.

[0013] The reactor disclosed in the present application comprises a reactor body, wherein the powder preparation and enrichment mechanism is arranged in the reactor body.

[0014] Preferably, the reaction kettle is provided with the agitator.

[0015] Preferably, the reactor comprises at least two agitators, and each agitator has at least two rotation directions.

[0016] The powder preparation method disclosed in the present application adopts the above-mentioned reaction kettle and is characterized in that it comprises the following steps:

[0017] Adding reactants into a reactor, reacting according to reaction conditions to produce a product;

[0018] The centrifugal impeller of the powder preparation and enrichment mechanism is turned on to suck the reactants and products into the enrichment container from the enrichment suction port, enter the centrifugal impeller from the suction port of the centrifugal impeller, and are thrown out to the peripheral side by the centrifugal impeller to the first filtering structure;

[0019] The inhaled reactants are returned to the reactor through the first filtering structure, and the target product is blocked and falls into the enrichment tank to be collected.

[0020] Preferably, the agitator of the reactor is started to rotate when the reactants react.

[0021] Preferably, when the reactants are added to the reactor, at least one reactant is added later, and the reaction rate is controlled by controlling the addition rate of the later added reactant.

[0022] The beneficial effects of the present invention are:

[0023] (1) The powder preparation and enrichment mechanism of the present application is used to separate the powder in time through the reaction, and after the reaction is completed, there is no need for subsequent complicated operations such as filtration and separation;

[0024] (2) Timely separation of the products can make the reaction faster, shorten the reaction time and improve the reaction efficiency;

[0025] (3) The products can be separated continuously, which helps to realize automated and continuous production.

[0026] (3) Through the filtration structure, not only can the reactants and products be separated well, but also the particle size of the product can be made more uniform;

[0027] (4) The device is relatively simple, easy to install and disassemble, and easy to implement;

[0028] (5) It has a wide range of applications. The reactants can be gases or liquids and can be used for high-temperature or medium-low-temperature reactions. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the reactor of the present application;

[0030] Figure 2 is a schematic diagram of the agitator of the present application;

[0031] Figure 3 It is a schematic diagram of the powder preparation and enrichment mechanism of the present application.

[0032] Figure numerals: agitator 1, powder preparation and enrichment mechanism 11, enrichment container 111, centrifugal impeller 112, first filtering structure 113, second filtering structure 114, enrichment tank 115, stirring rod 12, kettle body shell 2, kettle body 3, cover plate 4, feed port 5, exhaust hole 6. DETAILED DESCRIPTION

[0033] The present invention is further described below.

[0034] like Figure 3 As shown, the powder preparation enrichment mechanism 11 disclosed in the present invention comprises an enrichment container 111, wherein a centrifugal impeller 112 is vertically arranged with a central axis, an enrichment suction port is arranged at a position of the enrichment container 111 corresponding to the suction port of the centrifugal impeller 112, a first filter structure 113 is arranged on the side wall of the enrichment container 111 corresponding to the centrifugal direction of the circumference of the centrifugal impeller 112, the pore size of the first filter structure 113 is smaller than the particle size of the target product and larger than the particle size of the inhaled reactant, and an enrichment tank 115 is arranged in the enrichment container 111 corresponding to the lower part of the first filter structure 113.

[0035] The enrichment suction port is the entrance of the enrichment container 111, which can be used for the entry of the target product and the inhalable reactant. The first filter structure 113 is actually the outlet of the enrichment container 111, but it is only used for the inhaled reactant to go out, while the target product is blocked and collected in the enrichment tank 115. The target product refers to the product that reaches the target, and if there is a particle size requirement, it is also necessary to reach the particle size requirement. The bottom and surrounding of the enrichment tank 115 can adopt the first filter structure 113, or a closed structure can be adopted, such as using a non-porous plate to seal the bottom and surrounding of the enrichment tank 115. In most cases, the latter is a preferred embodiment, which can reduce the contact between the product in the enrichment tank 115 and the external reaction environment, and improve the external reaction rate. However, for reactions with a particle size lower limit requirement for the product, it is preferred to use the same first filter structure 113 preferably arranged around the enrichment tank 115, so that the product that does not meet the particle size lower limit requirement can be better thrown out.

[0036] The powder preparation and enrichment mechanism 11 can be directly placed in a reactor to prepare powder materials. The powder preparation method using the reactor in which the powder preparation and enrichment mechanism 11 is placed includes the following steps:

[0037] Adding reactants into a reactor, reacting according to reaction conditions to produce a product;

[0038] The centrifugal impeller 112 of the powder preparation and enrichment mechanism 11 is turned on to suck the reactants and products into the enrichment container 111 from the enrichment suction port, enter the centrifugal impeller 112 from the suction port of the centrifugal impeller 112, and are thrown out to the peripheral side by the centrifugal impeller 112 to the first filtering structure 113;

[0039] The inhaled reactants are returned to the reactor through the first filtering structure 113 , and the target products are blocked and fall into the enrichment tank 115 to be collected.

[0040] The present application can be used for the reaction of preparing powder materials in a liquid or gas environment, and can be applicable to various systems such as aqueous systems, organic systems, high-temperature molten salt systems, etc. For example, in the reaction for material a and material b to generate powder substance c, at least one of material a and material b is gaseous or liquid, and the other can be solid, and material a and material b can be a single substance or a mixture of multiple substances. Specific conditions such as temperature, atmosphere, pressure, etc. are set according to specific reactions.

[0041] The reactor can be selected according to the different powders and raw materials to be prepared, such as Figure 1As shown, when a certain liquid and gas react to prepare a powder, a reactor comprising a reactor shell 2 and a reactor body 3 can be used. The reactor shell 2 and the reactor body 3 are in direct contact, and the reactor body 3 can be freely withdrawn. The upper part is sealed with a cover plate 4, and a temperature control system is arranged in the middle. A feed port 5 and an exhaust hole 6 are arranged on the sealing cover. The feed port 5 is inserted below the liquid level of the reactants in the reactor to form a reaction zone, and a product is produced in the reaction zone.

[0042] The product connected to the reactant is sucked into the centrifugal impeller 112 in the enrichment container 111, and then thrown out to the first filter structure 113. The pore size of the first filter structure 113 is smaller than the particle size of the target product, so that the target product cannot pass through the first filter structure 113 and is blocked from falling into the enrichment tank 115 to be collected. The pore size of the first filter structure 113 is larger than the particle size of the inhaled reactant, so that the inhaled reactant can be returned to the reactor through the first filter structure 113 to continue to participate in the reaction. The target product refers to the product that reaches the target particle size. For example, although part of the product is sucked into the enrichment container 111, it will also be returned to the reactor if it does not reach the pore size of the first filter structure 113, so that the particle size of the product can be more uniform. After the product is enriched in the enrichment container 111, it is separated from the reactants, which can make the reaction outside the enrichment container 111 faster, shorten the reaction time, and improve the reaction efficiency. When the reaction is completed or the reactants need to be extracted, the enrichment container 111 is taken out, and the target powder material can be obtained without complicated filtering and separation operations.

[0043] It can be seen from the fact that the pore size of the first filter structure 113 is smaller than the particle size of the target product and larger than the particle size of the inhaled reactant that, in the actual present application, the particle size of the inhaled reactant is smaller than the target product, so the reactant material of the present application is mostly liquid or gas, and if it contains solids, the solids need to have a larger volume, for example, and cannot be inhaled into the enrichment container 111. In addition, suspended impurities may appear in some reactions, and they are also easily inhaled into the enrichment container 111 and enter the enrichment tank 115. For this reason, in a preferred embodiment of the present application, the enrichment inlet is provided with a second filter structure 114, and the pore size of the second filter structure 114 is larger than the diameter of the target product. Because the particle size of the target product is larger than the particle size of the inhalable reactant, the inhalable reactant will also be enriched by the enrichment container 111, but will be filtered out by the first filter structure 113. The second filter structure 114 can block suspended impurities and solid reactants with larger particle sizes outside the enrichment container 111, ensure the purity of the target product collection, and facilitate subsequent collection. In the experiment conducted by the applicant, the purity of the product can reach more than 95%.

[0044] A single enrichment container 111 may be provided with one or more centrifugal impellers 112, which are specifically set according to actual conditions. If a single enrichment container 111 is provided with a single centrifugal impeller 112, the centrifugal impeller 112 is located in the middle of the enrichment container 111, and the enrichment suction port is located in the middle of the top surface or the middle of the bottom surface of the enrichment container 111. The first filter structure 113 can be arranged around the centrifugal impeller 112 in the middle, and the first filter structure 113 can be arranged in a wider range, which is conducive to fully utilizing the space occupied by the enrichment container 111.

[0045] The powder preparation and enrichment mechanism 11 of the present application can be directly set in the reactor alone, or can be set on some parts of the reactor, such as Figure 1 and 2 As shown, in a preferred embodiment of the present application, all powder preparation and enrichment mechanisms 11 are arranged on the agitator 1, and the agitator 1 includes a stirring rod 12 and a stirring paddle connected to the stirring rod 12, and the stirring paddle adopts the powder preparation and enrichment mechanism 11, and the powder preparation and enrichment mechanism 11 is connected to the bottom of the stirring rod 12, and the enrichment suction port is arranged at the bottom of the enrichment container 111. The powder preparation and enrichment mechanism 11 is the stirring paddle of the agitator 1, and it is located in the middle of the reactor, which can not only better absorb the product, but also the ejected reactants can be quickly mixed into the reactor, which is conducive to the continuous and rapid progress of the reaction.

[0046] In order to facilitate the connection between the powder preparation enrichment mechanism 11 and the stirring rod 12 as a stirring paddle, the enrichment suction port is arranged on the side of the enrichment container 111 away from the stirring rod 12 and is located on the rotation center axis of the stirring paddle. The enrichment suction port is arranged on the rotation center axis of the stirring paddle to better inhale the reactants and products.

[0047] The agitator 1 is applied to the reactor, which can make the powder preparation and enrichment mechanism 11 play a better role and save the internal space of the reactor compared with the reactor with a separate powder preparation and enrichment mechanism 11. The reactor is usually only provided with one agitator 1, but one agitator 1 is easy to form a "vortex", so in the preferred embodiment of the present application, at least two agitators 1 are included, and each agitator 1 has at least two rotation directions. Each agitator 1 can disturb each other, and it is not easy to form a "vortex", so that the reaction is more complete.

[0048] The agitator 1 provided with the powder preparation and enrichment mechanism 11 is used. In a liquid environment, the rotation speed of the agitator 1 is preferably 100-150r / min. At this speed, the powder preparation and enrichment mechanism 11 can achieve a better collection effect. Of course, depending on the reaction, the rotation speed of the agitator 1 also needs to be adjusted, and ultimately the stirring effect of the agitator 1 in the reaction needs to be taken into account.

[0049] When the powder preparation and enrichment mechanism 11 of the present application is used to prepare the powder, since the product is separated out in time, the return rate will be greatly increased, and the rate of the product produced by the reaction should be equivalent to the separation rate of the product, so that the reaction proceeds more smoothly. In order to facilitate the control of the reaction rate, in the preferred embodiment of the present application, when the reactants are added to the reactor, at least one reactant is added later, and the reaction rate is controlled by controlling the feeding rate of the reactants added later. For example, when preparing lithium nitride powder at high temperature, the reaction rate is controlled by controlling the nitrogen introduction rate.

[0050] The following are two specific embodiments of the present application.

[0051] Example 1.

[0052] Take the high temperature preparation of lithium nitride powder as an example:

[0053] At room temperature, lithium metal reacts with nitrogen to generate some lithium nitride. At higher temperatures, lithium metal reacts more violently and thoroughly with nitrogen. Lithium nitride powder has been used in many fields as a catalyst or a nitrogen source for related reactions. Here is a brief description of the preparation method of lithium nitride powder.

[0054] The high-temperature preparation of lithium nitride powder can be roughly divided into four steps: ① gas washing, ② material addition and melting, ③ ventilation reaction, and ④ centrifugal separation.

[0055] ① Gas washing: Considering the activity of metallic lithium, the reactor can be washed with inert gases such as argon and helium to remove moisture and oxygen in the reactor, so that the entire reaction preparation process can be carried out under an inert gas protective atmosphere.

[0056] ② Add materials and melt: Weigh a certain weight of lithium metal into the reactor. The lithium metal is battery-grade lithium ingots, lithium blocks or lithium strips. Start heating at about 200°C to slowly melt the lithium metal into liquid lithium metal. Lower the stirrer 1 to a position 2 / 3 below the liquid state, start stirring, and the speed is 100-150r / min.

[0057] ③ Ventilation reaction: Open the control valve of the feed port 5 on the reaction sealing cover, slowly introduce high-purity nitrogen gas, and at the same time, lower the two stirrers 1 to a position 2 / 3 below the liquid level, start stirring, and the speed is in the range of 100-150r / min. At this time, the nitrogen and liquid metal lithium react violently in the reaction zone to generate small lithium nitride particles.

[0058] ④ Centrifugal separation: The small lithium nitride particles sink to the middle and lower part as the reaction proceeds, and then enter the centrifugal impeller 112 of the powder preparation enrichment mechanism 11 through the second filter structure 114 with a mesh size of 5000 and a pore size of 2.6um along with the liquid lithium. Under the action of the centrifugal impeller 112, the liquid lithium is thrown upward through the first filter structure 113 with a mesh size of 10000 and a pore size of 0.5um and returns to the reactor to continue to react with nitrogen, while the small lithium nitride particles are blocked by the first filter structure 113 and settle to the enrichment tank 115 at the bottom of the centrifugal zone. The reactants centrifuged out react again in the reaction zone, and the remaining space is quickly filled with the mixture sucked in from the bottom, and the cycle is repeated until the reaction is basically completed and the reaction end point is reached.

[0059] Example 2.

[0060] Take the preparation of lithium carbonate powder as an example:

[0061] Lithium carbonate is an inorganic compound that is slightly soluble in water. It is widely used in ceramics, glass, medicine and other fields. There are many methods for preparing lithium carbonate, among which the sulfuric acid method is the most common. Since the entire preparation process is relatively long, only the preparation process of lithium carbonate prepared by the reaction of lithium sulfate and sodium carbonate is introduced here as an example.

[0062] The method for preparing lithium carbonate comprises the following steps: adding a lithium sulfate solution of 2 / 3 of the kettle height to a reactor, opening a control valve of a feed port 5, slowly adding a sodium carbonate solution, and at the same time, lowering two agitators 1 to a position 2 / 3 below the liquid level, starting stirring, and rotating at a speed within the range of 100-150 r / min. At this time, the sodium carbonate and the lithium sulfate solution react in the reaction zone to generate small lithium carbonate particles, and sink to the middle and lower part as the reaction proceeds, and then pass through the second filter structure 114 of 100 mesh and 150 um pore size with the lithium sulfate. The centrifugal impeller 112 of the powder preparation enrichment mechanism 11, under the action of the centrifugal impeller 112, the reactant is thrown around and thrown off through the first filter structure 113 of 800 mesh and 15 um pore size to return to the reactor to continue the reaction, and the remaining space is quickly filled with the mixed material sucked from the bottom, and the cycle is repeated until no more small lithium carbonate particles are generated, the reaction is basically completed, and the reaction end point is reached.

Claims

1. A powder preparation and enrichment mechanism (11), characterized in that: The invention comprises an enrichment container (111), wherein a centrifugal impeller (112) with a central axis arranged vertically is arranged in the enrichment container (111), an enrichment suction port is arranged in the enrichment container (111) at a position corresponding to the suction port of the centrifugal impeller (112), a first filter structure (113) is arranged on the side wall of the enrichment container (111) in a circumferential centrifugal direction corresponding to the centrifugal impeller (112), the pore size of the first filter structure (113) is smaller than the particle size of the target product and larger than the particle size of the inhaled reactant, and an enrichment tank (115) is arranged in the lower part of the enrichment container (111) corresponding to the first filter structure (113).

2. The powder preparation and enrichment device (11) according to claim 1, characterized in that: The enrichment suction port is provided with a second filter structure (114), and the pore size of the second filter structure (114) is larger than the diameter of the target product.

3. The powder preparation and enrichment device (11) according to claim 1 or 2, characterized in that: A single centrifugal impeller (112) is arranged in a single enrichment container (111), wherein the centrifugal impeller (112) is located in the middle of the enrichment container (111), and the enrichment suction port is located in the middle of the top surface or the middle of the bottom surface of the enrichment container (111).

4. The powder preparation and enrichment mechanism (11) according to claim 1, characterized in that: The bottom and surrounding of the bottom of the enrichment tank (115) adopt a closed structure or a first filtering structure (113).

5. Agitator (1), characterized in that: It comprises a stirring rod (12) and a stirring paddle connected to the stirring rod (12), wherein the stirring paddle adopts the powder preparation and enrichment mechanism (11) as claimed in any one of claims 1 to 3.

6. The stirrer (1) according to claim 5, characterized in that: The enrichment suction port is arranged on a side of the enrichment container (111) away from the stirring rod (12), and is located on the rotation center axis of the stirring paddle.

7. A reaction kettle, comprising a kettle body (3), characterized in that: The kettle body (3) is provided with a powder preparation and enrichment mechanism (11) as described in any one of claims 1 to 3.

8. The reactor according to claim 7, characterized in that: A stirrer (1) as claimed in claim 5 or 6 is provided.

9. The reactor according to claim 8, characterized in that: It comprises at least two stirrers (1), and each stirrer (1) has at least two rotation directions.

10. A method for preparing a powder, characterized in that: The reactor according to any one of claims 7 to 9 is characterized in that it comprises the following steps: Adding reactants into a reactor, reacting according to reaction conditions to produce a product; The centrifugal impeller (112) of the powder preparation and enrichment mechanism (11) is turned on to suck the reactants and products into the enrichment container (111) from the enrichment suction port, enter the centrifugal impeller (112) from the suction port of the centrifugal impeller (112), and are thrown out to the peripheral side by the centrifugal impeller (112) to the first filtering structure (113); The inhaled reactants are returned to the reactor through the first filtering structure (113), and the target products are blocked and fall into the enrichment tank (115) to be collected.

11. The powder preparation method according to claim 10, characterized in that: The reactor is provided with an agitator (1) as claimed in claim 5 or 6; When the reactants react, the stirrer (1) is started to rotate.

12. The powder preparation method according to claim 10, characterized in that: When the reactants are added to the reactor, at least one reactant is added later, and the reaction rate is controlled by controlling the addition rate of the reactant added later.

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