Calcining apparatus, calcined product recovery apparatus, calcined product production method and calcined product recovery method

Abstract

To provide a calcining apparatus, a calcined product recovery apparatus, a calcined product production method and a calcined product recovery method which can efficiently recover a calcined product from a sagger even if it is massive.SOLUTION: A calcining apparatus according to the present disclosure comprises: a calcining part 3 for calcining materials M stored in a sagger S to obtain a calcined product C; and a recovery part 4 configured to recover the calcined product C. The recovery part 4 comprises: a turning part 41 configured to turn the sagger S so that an opening part O faces downward; and an impact application part configured to apply physical impact on the sagger S with the opening part O facing downward and / or the calcined product C stored in the sagger S.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a firing apparatus, a firing product recovery apparatus, a firing product manufacturing method, and a firing product recovery method. [Background technology]

[0002] A roller hearth kiln is a device that uses rollers to transport saggers containing raw materials and sinters the raw materials inside the saggers in the firing section. It is widely used in the production of positive and negative electrode materials for all-solid-state batteries and lithium-ion batteries, as well as electronic components such as MLCCs.

[0003] Here, for example, lithium metal composite oxides such as lithium cobalt oxide and lithium nickel-cobalt manganese oxide are used as the positive electrode material of lithium ion batteries. The lithium metal composite oxide is formed as a fired product by, for example, mixing lithium hydroxide and a composite metal hydroxide, placing the mixture in a sagger, and firing the mixture. The sagger is then further transported, and in a recovery section for recovering the fired product, the sagger is inverted so that the opening of the sagger faces downward, causing the fired product contained in the sagger to fall and be recovered below.

[0004] In this type of firing process, if the firing raw materials contained in the sagger are tall, oxygen may not reach the bottom of the sagger sufficiently, the temperature may rise quickly until the lithiation reaction occurs due to differences in the way heat is applied, or the lithium may melt prematurely and act as a sintering aid, causing the firing to proceed prematurely.As a result, the lithium hydroxide and the composite metal hydroxide do not react, and unreacted lithium hydroxide remains. This acts as a glue to adhere the fired product to the sagger, and it does not fall when the sagger is inverted, making it impossible to recover the fired product.

[0005] To address this issue of adhesion of fired materials to saggers, for example, Patent Document 1 proposes a powder recovery device that includes at least one air blowing tube that blows air toward the inner wall surface of the sagger, and a suction device that sucks up powder detached from the inner wall surface by the air blown from the air blowing tube. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2018-169138 A Summary of the Invention [Problem to be solved by the invention]

[0007] It has been reported that the powder recovery device described in Patent Document 1 can efficiently recover powder adhering to the inner wall surface of a sagger. However, the fired material is not necessarily in powder form, and may be in the form of clumps due to melting during firing or the action of ingredients that act as a glue, such as the lithium hydroxide mentioned above, and the suction device may not be able to suck up fired material in such a state.

[0008] The present disclosure has been made in consideration of the above-described situation, and aims to provide a firing device that can efficiently recover even chunky fired products from a sagger, a firing product recovery device, a firing product manufacturing method, and a firing product recovery method. [Means for solving the problem]

[0009] The present inventors conducted extensive research to solve the above-mentioned problems. As a result, they found that a firing device having a firing section that fires raw materials contained in a sagger to obtain a fired product, and a recovery section configured to be able to recover the fired product, the recovery section having a turning section configured to be able to turn the sagger so that the opening faces downward, and an impact applying section configured to be able to apply a physical impact to the sagger with the opening facing downward and / or the fired product contained in the sagger, can efficiently recover even a lump-shaped fired product from the sagger. Specifically, the present disclosure provides the following.

[0010] (1) a firing section for firing raw materials contained in a sagger to obtain a fired product; A recovery section configured to recover the fired product, The recovery unit includes a turning unit configured to be able to turn the sagger so that the opening faces downward, and an impact applying unit configured to be able to apply a physical impact to the sagger with the opening facing downward and / or the baked product in which the sagger is housed. Baking equipment.

[0011] (2) The baking apparatus according to (1), wherein the impact applying unit is configured to be capable of injecting gas into an opening of the sagger and / or into the object to be baked contained in the sagger.

[0012] (3) The firing apparatus according to (2), wherein the impact applying unit is configured to be able to inject the gas at least near an inner wall surface of the opening of the sagger.

[0013] (4) The impact applying unit is configured to be capable of injecting gas at 0.1 MPa or more and 16 MPa or less. 4. The baking apparatus according to claim 2 or 3.

[0014] (5) A recovery device for recovering fired products contained in a sagger, A turning unit configured to be able to turn the sagger so that an opening faces downward; and an impact applying unit configured to apply a physical impact to the sagger with the opening facing downward and / or the baked product contained in the sagger. A device for recovering fired products.

[0015] (6) a firing step of firing the raw materials contained in the sagger to obtain a fired product; a rotating step of rotating the sagger so that the opening faces downward; and applying a physical impact to the sagger with the opening facing downward and / or the baked product contained in the sagger. A method for producing a fired product.

[0016] (7) A method for recovering fired material contained in a sagger, comprising the steps of: a rotating step of rotating the sagger so that the opening faces downward; and applying a physical impact to the sagger with the opening facing downward and / or the fired product contained in the sagger. How to recover fired products.

[0017] According to the present disclosure, it is possible to provide a firing device that can efficiently recover even chunky fired products from a sagger, a firing product recovery device, a firing product manufacturing method, and a firing product recovery method. [Brief description of the drawings]

[0018] [Figure 1] FIG. 1 is a schematic diagram of a baking device according to an embodiment of the present disclosure. [Diagram 2] 1 is a schematic diagram showing a turning section according to an embodiment of the present disclosure and its deployed state. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Hereinafter, embodiments of the present disclosure will be described, however, the present disclosure is not limited in any way to the description of the embodiments and can be implemented with appropriate modifications.

[0020] In addition, in this disclosure, the notation "X to Y" means "greater than or equal to X and less than or equal to Y." In addition, in this disclosure, the term "below" is used, and "below" refers to the direction of gravity and a direction that forms an angle of ±10° with the direction of gravity.

[0021] <Baking equipment> A firing device according to an embodiment of the present disclosure has a firing section that fires raw materials contained in a sagger to obtain a fired product, and a recovery section configured to be able to recover the fired product, and the recovery section has a turning section configured to be able to turn the sagger so that its opening faces downward, and an impact application section configured to be able to apply a physical impact to the sagger with its opening facing downward and / or the fired product contained in the sagger.

[0022] Hereinafter, a roller hearth kiln as an embodiment of a firing device will be described with reference to the drawings, but the type of firing furnace is not particularly limited. Fig. 1 is a schematic diagram of a firing device according to an embodiment of the present disclosure. The firing device 1 according to an embodiment of the present disclosure mainly includes a raw material supply section 2, a firing section 3, a recovery section 4, and a sagger cleaning section 5.

[0023] Each section will be explained in detail below. The rollers move the sagger S in the direction of D, and the raw materials are processed by passing through each section in order.

[0024] [Raw material supply department] In the raw material supplying unit 2, the raw material is discharged from a supply hole of the raw material supplying unit such as a nozzle into a sagger and stored therein. Note that the raw material supplying unit 2 is not an essential component of the present disclosure.

[0025] When the raw material consists of two or more kinds of materials, the multiple materials may be mixed in advance and discharged in a mixed state into the sagger, or multiple raw material supply units 2 may be provided, and the multiple materials may be mixed by storing them in the sagger by switching the raw materials to be supplied.

[0026] [Baking section] In the firing section 3, the raw materials contained in the saggers are fired to obtain a fired product.

[0027] The firing conditions (temperature, atmosphere, time, etc.) are not particularly limited and may be determined taking into consideration the composition, shape, amount, production cost, etc. of the desired fired product.

[0028] In one embodiment, it is preferable to separate the upstream side into a heating section and the downstream side into a cooling section. The upstream heating section is provided with a heater, which heats the raw materials to a temperature at which they are fired, causing a predetermined reaction to occur and obtaining the desired fired product. Meanwhile, the downstream cooling section is provided with a cooler, and the temperature is controlled. In one embodiment, the fired product that has reached a high temperature here is gradually cooled.

[0029] [Collection Department] The recovery section 4 has a turning section configured to be able to turn the sagger so that its opening faces downward, and an impact application section configured to be able to apply a physical impact to the sagger with its opening facing downward and / or the fired product contained in the sagger.

[0030] Fig. 2 is a schematic diagram showing a turning section according to an embodiment of the present disclosure and its deployment. The turning section 41 shown in Fig. 2 is composed of a support 411 that supports the sagger S and a rotating shaft 412 that transmits a rotational force to the support 411 (Fig. 2(a)). The sagger S transported from the outside is fixed by the support 411 (Fig. 2(b)), and then turns in the R direction around the rotating shaft 412 (Fig. 2(c)). Even if the sagger S turns so that the opening O of the sagger S faces downward (Fig. 2(d)), the sagger S itself does not fall, and only the fired product C contained in the sagger S falls and is collected.

[0031] The method for fixing the sack S to the support 411 is not particularly limited, and may be, for example, by clamping the sack S from both sides or by pressing the upper edge of the sack (not shown).

[0032] In this way, when the opening O of the sagger S faces downward, i.e., when in the state shown in Figure 2(d), the impact application section is configured to be able to apply a physical impact to the sagger S and / or the fired product C contained in the sagger S.

[0033] The impact application unit is not particularly limited, but in one embodiment, it may be composed of a striking tool such as a hammer that strikes the object and a mechanism for shaking it, and the striking tool may be configured to strike the bottom surface and / or outer wall surface and / or support body 411 of the sagger S (in a state in which a physical impact can be transmitted to the sagger S) with the opening O of the sagger S facing downward.

[0034] In one embodiment, the sack S and / or other solid body may be moved to cause the sack S to collide with the other solid body. For example, the impact applying unit may be configured to move the sack S and / or other solid body so that the sack S and the solid body collide with each other with the opening O facing downward.

[0035] In one embodiment, the impact applying unit may be configured to vibrate the sack S. Examples of the vibration means include a device that moves the sack S back and forth in small increments, and a device that irradiates sound waves such as ultrasonic waves.

[0036] Furthermore, in one embodiment, it is preferable to use an impact applying unit that is configured to be able to inject gas into the opening O of the sagger S. It is also possible to peel off the fired body C from the sagger S by injecting gas and striking it against the fired body C in the sagger S. The sagger S is generally made of special ceramics and is expensive, while it is prone to cracking and surface peeling due to repeated heating and cooling in firing applications. If it is further struck with a hammer or struck against or collided with another solid body, the mechanical strength will be further reduced, and the life of the sagger S may be shortened. On the other hand, if gas is injected, the mechanical strength is hardly reduced by the application of physical impact, and economic efficiency can be improved.

[0037] Furthermore, in one embodiment, when the inversion part rotates two or more times, it is preferable that the impact applying part injects gas once or more during the second or subsequent rotation of the inversion part (when the sagger faces the opening O downward for the second time). By facing the opening O downward at least once before gas injection, it is possible to remove materials that may fall naturally and to inject gas to peel off only the fired body that needs to be peeled off. Note that when the opening O is faced downward multiple times from the second time onwards, gas may be injected every time, or gas may be injected some of those times.

[0038] When gas is injected, the impact application unit is preferably configured to be able to inject gas at least near the inner wall surface of the opening O of the sagger S. By injecting gas near the inner wall surface of the opening O of the sagger S, the injected gas passes through to the inside, and the fired product C adhering to the bottom surface and inner wall surface can be peeled off more efficiently.

[0039] In addition, when gas is injected, it is preferable that the impact application unit is configured to be able to inject gas into the cracks in the baked product C. By injecting gas into the cracks in the baked product C, the injected gas passes through to the inside, and the baked product C adhering to the bottom surface or inner wall surface can be peeled off more efficiently. Note that the cracks in the baked product C may be judged visually, or may be judged from the surface contrast of the baked product C by image processing.

[0040] The pressure of the gas injected by the impact applying unit is not particularly limited, but is preferably 0.1 MPa or more, 0.2 MPa or more, or 0.3 MPa or more. By the pressure of the gas injected by the impact applying unit being equal to or more than the required value, the lump-shaped baked product C is easily broken down by the pressure of the injected gas, and the baked product C attached to the bottom surface or inner wall surface can be peeled off more efficiently. On the other hand, the pressure of the gas injected by the impact applying unit is preferably 16 MPa or less, 13 MPa or less, 10 MPa or less, 9.5 MPa or less, 9 MPa or less, 8.5 MPa or less, 8 MPa or less, 7.5 MPa or less, 7 MPa or less, 6.5 MPa or less, 6 MPa or less, 5.5 MPa or less, 5 MPa or less, 4.5 MPa or less, 4 MPa or less, 3.5 MPa or less, 3 MPa or less, 2.5 MPa or less, 2 MPa or less, 1.5 MPa or less, 1.2 MPa or less, or 1 MPa or less. By ensuring that the pressure of the gas ejected by the impact application unit is equal to or greater than a required value, it is possible to further prevent the mechanical strength of the sagger from being reduced due to the application of a physical impact.

[0041] The atmosphere of the gas injected by the impact applying unit is not particularly limited, but is preferably an inert gas, for example. This can prevent the reaction of the fired product C with the gas and suppress the generation of impurities. In particular, the atmosphere of the gas injected by the impact applying unit preferably has a carbon dioxide concentration of 400 ppm or less, 350 ppm or less, 300 ppm or less, 250 ppm or less, 200 ppm or less, 150 ppm or less, 100 ppm or less, 80 ppm or less, 50 ppm or less, 30 ppm or less, 20 ppm or less, or 10 ppm or less. Lithium-containing materials, including the positive electrode material of a lithium-ion secondary battery, react with carbon to produce lithium carbonate, which has a negative effect on the performance of the battery, but the generation of this lithium carbonate can be suppressed by having the carbon dioxide concentration be equal to or less than a required value. On the other hand, the atmosphere of the gas injected by the impact applying unit may be 0 ppm or more, 1 ppm or more.

[0042] The temperature of the gas sprayed by the impact application unit is not particularly limited and may be, for example, room temperature, or may be cooled or heated, but it is preferably, for example, 200°C or less, 170°C or less, 150°C or less, 120°C or less, 100°C or less, 70°C or less, or 50°C or less.

[0043] The gas injection time of the impact applying part is not particularly limited, but is preferably, for example, 0.1 seconds or more, 0.2 seconds or more, 0.3 seconds or more, 0.4 seconds or more, 0.5 seconds or more, 0.6 seconds or more, 0.7 seconds or more, 0.8 seconds or more, 0.9 seconds or more, or 1 second or more. The gas injection time of the impact applying part may be the entire time during which the opening O of the sagger S faces downward, and may be, for example, 5 seconds or less, 4.5 seconds or less, 4 seconds or less, 3.5 seconds or less, 3 seconds or less, 2.5 seconds or less, 2 seconds or less, or 1.5 seconds or less.

[0044] The physical impact applied by the impact applying unit may be a combination of gas injection and vibration of a sagger.

[0045] [Casket Cleaning Department] The sagger cleaning section 5 is for removing and cleaning powder and the like of the sagger S from the sintered material C that has fallen from the recovery section 4 and remains in the recesses of the sagger S.

[0046] The cleaning method is not particularly limited as long as it can remove the remaining powder of the fired product C. For example, the concave portion of the sagger may be scrubbed with a brush or blown with air.

[0047] In the above embodiment, a roller hearth kiln has been used as an example. However, the firing apparatus of the present disclosure is not limited to a roller hearth kiln and may be a stationary furnace, pusher furnace, or the like, as long as it fires the raw materials in a sagger and has a collection section similar to collection section 4.

[0048] <Production method of fired products> A method for producing a fired product according to an embodiment of the present disclosure includes a firing step of firing raw materials contained in a sagger to obtain a fired product, a rotation step of rotating the sagger so that its opening faces downward, and an impact application step of applying a physical impact to the sagger with its opening facing downward and / or the fired product contained in the sagger.

[0049] This method for producing a fired product can be carried out, for example, by using the firing apparatus 1 described above.

[0050] [Raw material preparation process] In the raw material preparation process, multiple raw materials are mixed as necessary, and then the raw materials discharged from the raw material supply unit of the raw material preparation unit 2 are stored in a sagger that circulates on rollers.

[0051] [Firing process] In the firing process, the raw materials contained in the saggers are fired to obtain a fired product. The saggers containing the raw materials from the raw material preparation process are transported along the rollers to the firing section 3, where they are passed through a passage heated by a heater, where the raw materials are subjected to a heat treatment.

[0052] [Turning process] In the turning step, the sagger is turned so that the opening faces downward. The sagger containing the fired product obtained in the firing step is transported to the recovery section 4.

[0053] [Impact application process] In the above-mentioned turning step, when the sagger is turned so that the opening faces downward, some of the fired products may fall, but some of the fired products may stick to the inside of the sagger and not fall. Therefore, in the impact application step, a physical impact is applied to the downward-facing sagger and / or the fired products contained in the sagger. Specific examples of the physical impact are as described above.

[0054] <Baked product recovery device> A fired product recovery device according to an embodiment of the present disclosure is a recovery device that recovers fired products contained in a sagger, and has a turning unit configured to be able to turn the sagger so that its opening faces downward, and an impact application unit configured to be able to apply a physical impact to the sagger with its opening facing downward and / or the fired product contained in the sagger.

[0055] This recovery device has a similar configuration to the recovery section 4 of the above-mentioned firing device 1, so a description thereof will be omitted here.

[0056] <How to collect fired products> A method for recovering a fired material according to an embodiment of the present disclosure is a method for recovering a fired material contained in a sagger, and includes a rotation step of rotating the sagger so that its opening faces downward, and an impact application step of applying a physical impact to the sagger with its opening facing downward and / or the fired material contained in the sagger.

[0057] This recovery method has the same configuration as the recovery step in the above-mentioned calcined product production method, so a detailed description thereof will be omitted here.

[0058] In this specification, an example of calcining a lithium metal composite oxide as a calcined product has been mainly described. However, the calcined product in the calcination apparatus, the calcined product recovery apparatus, the calcined product manufacturing method, and the calcined product recovery method of the present disclosure is not limited to lithium metal composite oxide, and may be made of various ceramic materials, resin materials, or the like, and is not particularly limited in terms of material.

[0059] In cases where an adhesive that bonds two solids consisting of the raw materials, the fired product, by-products, impurities, and the sagger is contained in the raw materials or is produced by firing or reaction, where one or more of the raw materials, fired product, by-products, and impurities react with the sagger, where the raw materials have a small particle size and poor fluidity, or where firing is performed at high temperatures (for example, 1000°C or higher when synthesizing ceramic materials), it is difficult to recover the fired product by simply facing the opening of the sagger downward.However, the firing apparatus, fired product recovery apparatus, fired product manufacturing method, and fired product recovery method disclosed herein allow the fired product to be efficiently recovered even in the above cases. EXAMPLES

[0060] The present disclosure will be described in more detail below with reference to examples, but the present disclosure is not limited to these examples.

[0061] A mixed aqueous solution was obtained by mixing an aqueous nickel sulfate solution, an aqueous cobalt sulfate solution, and an aqueous aluminum sulfate solution so that the ratio (molar ratio) of Ni, Co, and Al was Ni:Co:Al=90:5:5. In the reaction vessel, 10 L of pure water to which 300 g of an aqueous sodium hydroxide solution and 500 g of an aqueous ammonia solution had been added was prepared in advance, and the reaction vessel was filled with nitrogen gas at a flow rate of 0.7 L / min to create a nitrogen atmosphere, and the reaction was also carried out in a nitrogen atmosphere.

[0062] Thereafter, while rotating the stirring blade at 1000 rpm, the mixed aqueous solution, sodium hydroxide aqueous solution, and ammonia water were simultaneously dropped at a predetermined rate, and the amount of the alkaline solution dropped was adjusted so that the pH became 11.7. Through a crystallization reaction, Ni, Co, and Al were crystallized and coprecipitated to form agglomerated particles, thereby obtaining a coprecipitate.

[0063] After that, the slurry in the reactor was separated into solid and liquid, and further washed with pure water to reduce residual impurities. The coprecipitate cake was then dried at 100°C for 10 hours in an air environment to obtain the product with the formula Ni 0.90 Co 0.05 Al 0.05 A nickel-cobalt-aluminum composite hydroxide represented by (OH)2 was obtained.

[0064] Next, the obtained nickel-cobalt-aluminum composite hydroxide was oxidized by heat treatment at 650° C. for 6 hours in the air (oxygen concentration: 21 vol%) to obtain a nickel-cobalt-aluminum composite oxide.

[0065] The obtained nickel-cobalt-aluminum composite oxide and anhydrous lithium hydroxide were weighed and mixed so as to have a molar ratio of Li / (Ni+Co+Al)=1.030 to obtain a mixture.

[0066] The obtained mixture was fired using a firing apparatus 1 shown in Fig. 1. Specifically, 14 kg of the mixture was filled into a mullite sagger measuring 330 mm in length, 330 mm in width, and 150 mm in height from a raw material supply section 2. The sagger was then transported to a firing section 3, where it was fired in an oxygen atmosphere (oxygen concentration: 97 vol%) at a maximum temperature of 740°C for 4 hours, cooled, and then discharged from the firing section 3.

[0067] The discharged sack was transported to the collection section 4 by rollers, and the sheath was fixed by pinching it from both ends. The sack was then turned 180 degrees by rotating it at a speed of 40 rpm, and held for 3 seconds with the opening facing downward. This turning and holding for 3 seconds was repeated a total of 3 times.

[0068] The two saggers in which the fired products remained after this operation were turned over again in the recovery section 4 and held for three seconds, a total of three times. During the first two of the three times the openings were held facing downward, decarbonated air (carbon dioxide concentration: 10 ppm or less) was blown at a pressure of 2 MPa using an air gun with a diameter of φ4 mm to give the fired products a physical shock. At this time, the air was blown near the inner wall of the sagger. Specifically, air was introduced into the gap between the fired products and the inner wall of the sagger, which had formed as the fired products contracted inside the sagger. As a result, almost all of the fired products fell out in both saggers.

[0069] As described above, by applying an impact to the sack and / or the fired products contained therein with the opening of the sack facing downward, it is possible to recover fired products that cannot be recovered by simply inverting the sack. [Explanation of symbols]

[0070] 1. Baking equipment 2 Raw material supply section 3. Baking section 4. Collection Section 41 Turning Section 411 Support 412 Rotational Axis 5. Sack Bowl Cleaning Department

Claims

1. a firing section for firing the raw materials contained in the sagger to obtain a fired product; A recovery section configured to recover the fired product, The recovery unit includes a turning unit configured to be able to turn the sagger so that the opening faces downward, and an impact applying unit configured to be able to apply a physical impact to the sagger with the opening facing downward and / or the baked product contained in the sagger. Baking equipment.

2. The impact applying unit is configured to inject gas into an opening of the sagger and / or into the baked object contained in the sagger. The baking apparatus according to claim 1 .

3. The impact applying unit is configured to inject the gas at least near an inner wall surface of the opening of the sagger. The baking apparatus according to claim 2.

4. The impact applying unit is configured to be capable of injecting gas at a pressure of 0.1 MPa or more and 16 MPa or less. The baking apparatus according to claim 2 or 3.

5. A recovery device for recovering fired material contained in a sagger, A turning unit configured to be able to turn the sagger so that an opening faces downward; and an impact applying unit configured to apply a physical impact to the sagger with the opening facing downward and / or the baked product contained in the sagger. A device for recovering fired products.

6. a firing step of firing the raw material contained in the sagger to obtain a fired product; a rotating step of rotating the sagger so that the opening faces downward; and applying a physical impact to the sagger with the opening facing downward and / or the fired product contained in the sagger. A method for producing a fired product.

7. A method for recovering fired material contained in a sagger, comprising the steps of: a rotating step of rotating the sagger so that the opening faces downward; and applying a physical impact to the sagger with the opening facing downward and / or the fired product contained in the sagger. How to recover fired products.

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