A firing apparatus, an apparatus for recovering fired material, a method for producing fired material, and a method for recovering fired material

Abstract

The present invention provides a firing apparatus comprising a firing portion (3) for firing a starting material (M) accommodated in a sagger (S) to obtain a fired material (C); and a recovery portion (4) configured to be capable of recovering the fired material (C), the recovery portion (4) comprising a turnover portion (41) configured to be capable of turning over the sagger (S) so that an opening portion (O) thereof is directed downward, and an impact applying portion configured to be capable of applying a physical impact to the sagger (S) with the downwardly directed opening portion (O) and / or to the fired material (C) accommodated in the sagger (S).

Description

[0001] A FIRING APPARATUS, AN APPARATUS FOR RECOVERING FIRED MATERIAL, A METHOD FOR PRODUCING FIRED MATERIAL, AND A METHOD FOR RECOVERING FIRED MATERIAL

[0002] TECHNICAL FIELD

[0003] The present disclosure relates to a firing apparatus, an apparatus for recovering a fired material, a method for producing a fired material, and a method for recovering a fired material.

[0004] BACKGROUND

[0005] A roller hearth kiln is an apparatus in which a sagger accommodating a starting material is conveyed by rollers, and the starting material inside the sagger is fired in a firing portion, and roller hearth kilns are widely used in the manufacture of electronic components, typically MLCC and positive electrode materials and negative electrode materials for all-solid-state batteries and lithium ion batteries.

[0006] Here, a lithium metal composite oxide such as lithium cobalt oxide or lithium nickel cobalt manganese oxide is used as the positive electrode material of a lithium ion battery, for example. Lithium metal composite oxides are formed as a fired material by mixing lithium hydroxide and a composite metal hydroxide and placing the mixture inside a sagger, then firing the mixture, for example. After this, the sagger is further conveyed to a recovery portion for recovering the fired material, the sagger is inverted so that the opening of the sagger is directed downward, and the fired material accommodated in the sagger drops out to be recovered below.

[0007] In this kind of firing process, when the firing starting material is accommodated inside the sagger to a certain height, oxygen may not adequately reach the bottom area of the sagger, a temperature increase rate until a lithiation reaction occurs may accelerate due to heat being differently applied, and the lithium may melt at an early stage, acting as a sintering aid, so that firing proceeds at an early stage, and unreacted lithium hydroxide may remain because the lithium hydroxide and the composite metal hydroxide do not react, adhering to the fired material and the sagger as an adhesive so that the fired material does not drop out when the sagger is inverted and cannot be recovered.

[0008] In order to deal with this adhesion of the fired material to the sagger, JP2018-169138A, for example, has proposed a powder recovery apparatus comprising at least one air blowout pipe for blowing out air toward an inner wall surface of a sagger, and a suction device for sucking a powder which was detached from the inner wall surface by means of the air blown from the air blowout pipe.

[0009] The powder recovery apparatus disclosed in JP2018-169138A is reported to be capable of efficiently recovering the powder adhering to the inner wall surface of the sagger. However, the fired material is not necessarily limited to a powder, and it may also melt because of the firing, or form clumps due to the action of components acting as an adhesive, as with lithium hydroxide, and the suction device may not be capable of sucking the fired material which is in this kind of state. SUMMARY OF THE INVENTION

[0010] The present disclosure takes account of the situation described above, and the objective thereof lies in providing a firing apparatus, an apparatus for recovering a fired material, a method for producing a fired material, and a method for recovering a fired material, capable of efficiently recovering a fired material from a sagger, even when the fired material is in the form of clumps.

[0011] The inventors engaged in extensive research to solve the problems noted above. As a result, it was found that a fired material can be efficiently recovered from a sagger, even when the fired material is in the form of clumps, by means of a firing apparatus comprising: a firing portion for firing a starting material accommodated in a sagger to obtain a fired material; and a recovery portion configured to be capable of recovering the fired material, wherein the recovery portion comprises a turnover portion configured to be capable of turning over the sagger so that an opening portion thereof is directed downward, and an impact applying portion configured to be capable of applying a physical impact to the sagger having the downwardly directed opening portion and / or to the fired material accommodated in the sagger.

[0012] According to the present disclosure, it is possible to provide a firing apparatus, an apparatus for recovering a fired material, a method for producing a fired material, and a method for recovering a fired material, capable of efficiently recovering a fired material from a sagger, even when the fired material is in the form of clumps.

[0013] DETAILED DESCRIPTION OF THE INVENTION

[0014] The undefined article “a”, “an”, “the” means one or more of the species designated by the term following said article.

[0015] In the context of the present disclosure, any specific values mentioned for a feature (comprising the specific values mentioned in a range as the end point) can be recombined to form a new range.

[0016] In the context of the present disclosure, each aspect so defined may be combined with any other aspect or aspects unless clearly indicated to the contrary. In particular, any feature indicated as being preferred or advantageous may be combined with any other feature or features indicated as being preferred or advantageous.

[0017] Firing Apparatus

[0018] A firing apparatus according to an embodiment of the present disclosure comprises: a firing portion for firing a starting material accommodated in a sagger to obtain a fired material; and a recovery portion configured to be capable of recovering the fired material, the recovery portion comprising a turnover portion configured to be capable of turning over the sagger so that an opening portion thereof is directed downward, and an impact applying portion configured to be capable of applying a physical impact to the sagger having the downwardly directed opening portion and / or to the fired material accommodated in the sagger.

[0019] A roller hearth kiln serving as an embodiment of the firing apparatus will be described below with the aid of the drawings, but there is no particular limitation as to the type of furnace. Figure 1 is an outline schematic diagram of a firing apparatus according to an embodiment of the present disclosure. A firing apparatus 1 according to the embodiment of the present disclosure mainly comprises a starting material supply portion 2, a firing portion 3, a recovery portion 4, and a sagger cleaning portion 5.

[0020] These portions will be described in detail below. Saggers S flow in a direction D by means of a flow produced by rollers, and a starting material is treated while following the order of the portions below.

[0021] In the starting material supply portion 2, a starting material is ejected from a supply hole in a starting material supply portion such as a nozzle and received in a sagger. It should be noted that the starting material supply portion 2 is not an essential component of the present disclosure.

[0022] When the starting material comprises two or more materials, the plurality of materials may be mixed beforehand and ejected into the sagger as a mixture, or a plurality of materials may be received in the sagger by providing a plurality of starting material supply portions 2 or switching the starting material being supplied, and thereby mixed.

[0023] In the firing portion 3, the starting material accommodated in the sagger is fired to obtain a fired material.

[0024] There are no particular limitations as to the firing conditions (temperature, atmosphere, time, etc.), and the firing conditions should be determined while taking account of the composition, shape, quantity and production cost, etc. of the intended fired material.

[0025] In an embodiment, the firing portion is preferably divided into a heating portion on an upstream side and a cooling portion on a downstream side. A heater is provided in the heating portion on the upstream side, and the starting material is heated to a firing temperature here, in order to produce a predetermined reaction for obtaining the intended fired material. Meanwhile, a cooler is provided in the cooling portion on the downstream side, and the temperature is controlled. In an embodiment, a fired material which reached a high temperature is steadily cooled here.

[0026] The recovery portion 4 comprises a turnover portion configured to be capable of turning over the sagger so that an opening portion thereof is directed downward, and an impact applying portion configured to be capable of applying a physical impact to the sagger having the downwardly directed opening portion and / or to the fired material accommodated in the sagger.

[0027] Figure 2 is an outline schematic diagram showing a turnover portion according to an embodiment of the present disclosure and a situation of deployment thereof. A turnover portion 41 shown in Figure 2 comprises: a support element 411 for supporting the sagger S; and a rotary shaft 412 for transmitting a rotational force to the support element 411. The sagger S which has been conveyed from outside is immobilized by means of the support element 411 , then turned over in a direction R about the rotary shaft 412. The sagger S itself does not drop even if it is turned so that an opening portion O of the sagger S is directed downward, and only the fired material C accommodated in the sagger S drops out to be recovered.

[0028] There is no particular limitation as to the method for immobilizing the sagger S on the support element 411, and the sagger S should be gripped from both sides, or upper edges of the sagger should be pressed down (not depicted).

[0029] An impact applying portion is configured to be capable of applying a physical impact to the sagger S and / or to the fired material C accommodated in the sagger S when the sagger S has been placed in a state in which the opening portion O is directed downward, i.e. , in the state in Figure 2.

[0030] There is no particular limitation as to the impact applying portion, but in one embodiment it is formed by a striking instrument such as a hammer, and a mechanism for actuating same, and the striking instrument which is used may be configured to be capable of striking a bottom surface and / or an outer wall surface of the sagger S and / or the support element 411 (a state in which a physical impact can be transmitted to the sagger S) in a state in which the opening portion O of the sagger S is directed downward.

[0031] In one embodiment, the sagger S and / or another fixed object may be moved so that the sagger S and the other fixed object collide with each other. For example, the impact applying portion may be configured to be capable of moving the sagger S and / or another fixed object, in a state in which the opening portion O of the sagger S is directed downward, so that the sagger and the fixed object collide with each other.

[0032] Furthermore, in one embodiment, the impact applying portion which is used may be configured to be capable of causing the sagger S to vibrate. Examples of vibration means that may be cited include a device for causing short, repeated reciprocating movements of the sagger S, and a device for radiating sound waves such as ultrasonic waves, etc.

[0033] In a further embodiment, the impact applying portion which is used is preferably configured to be capable of spraying a gas at the opening portion O of the sagger S. The fired material C can also be detached from the sagger S by spraying the gas so that it strikes the fired material C inside the sagger S. The sagger S is generally formed from a costly special ceramic, but cracking and surface detachment are likely to occur because of the repeated heating / cooling in firing applications. If the sagger is subjected to further impacts, such as being struck by a hammer, etc. or being made to collide with another fixed object, then there will be a greater reduction in mechanical strength, and a risk of the sagger S having a shorter lifespan. On the other hand, the reduction in mechanical strength resulting from application of a physical impact is virtually inconceivable if a gas is sprayed, and the economics are improved.

[0034] In a further embodiment, when an inverting portion rotates twice or more, the impact applying portion preferably sprays the gas once or twice or more at the second and subsequent rotations of the inverting portion (when the opening portion O of the sagger is directed downward for the second time). By directing the opening portion O downward at least once before the gas is sprayed, this enables material capable of dropping spontaneously to be removed so that only the fired material which needs to be detached by spraying the gas can be detached. Moreover, when the opening portion O is directed downward multiple times from the second time onward, the gas may be sprayed every time, or the gas may be sprayed for some of those times.

[0035] When the gas is sprayed, the impact applying portion is preferably configured to be capable of spraying the gas at least in the vicinity of the inner wall surface of the opening portion O of the sagger S. By spraying the gas in the vicinity of the inner wall surface of the opening portion O of the sagger S, the sprayed gas can pass through to the interior, enabling the fired material C adhering to the bottom surface and the inner wall surface to be detached more efficiently.

[0036] Furthermore, when the gas is sprayed, the impact applying portion is preferably configured to be capable of spraying the gas into cracks of the fired material C. By spraying the gas into cracks in the fired material C, the sprayed gas can pass through to the interior, enabling the fired material C adhering to the bottom surface and the inner wall surface to be detached more efficiently. Moreover, the cracks in the fired material C may be judged visually, or may be judged from the surface contrast, etc. of the fired material C using image processing.

[0037] There is no particular limitation as to the pressure of the gas which is sprayed by the impact applying portion, and it is preferably 0.1 MPa or more, 0.2 MPa or more, or 0.3 MPa or more, for example. By setting the pressure of the gas which is sprayed by the impact applying portion at or above the required value, the fired material C in the form of clumps is readily disintegrated by the pressure of the sprayed gas, enabling the fired material C adhering to the bottom surface and the inner wall surface to be detached more efficiently. Meanwhile, the pressure of the gas sprayed by the impact applying portion 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 setting the pressure of the gas which is sprayed by the impact applying portion at or above the required value, it is possible to further curb a reduction in the mechanical strength of the sagger that would be caused by the application of physical impacts.

[0038] There is no particular limitation as to the atmosphere of the gas which is sprayed by the impact applying portion, and an inert gas is preferred, for example. This makes it possible to prevent the fired material C from reacting with the gas, and to inhibit the formation of impurities. In particular, the atmosphere of the gas sprayed by the impact applying portion 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. A material comprising lithium, such as a positive electrode material for a lithium ion secondary battery, will react with carbon to form lithium carbonate which adversely affects battery performance, but by setting the carbon dioxide concentration at or below the required value, it is possible to inhibit the formation of lithium carbonate. Meanwhile, the atmosphere of the gas which is sprayed by the impact applying portion may have a carbon dioxide concentration of 0 ppm or more or 1 ppm or more. There is no particular limitation as to the temperature of the gas which is sprayed by the impact applying portion, and it may be normal temperature, or it may be cooled or it may be heated, for example, but the temperature is preferably 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, for example.

[0039] There is no particular limitation as to the time for which the gas is sprayed by the impact applying portion, but the time is preferably 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, for example. The time for which the gas is sprayed by the impact applying portion may be the entire time during which the opening portion O of the sagger S is directed downward, and it 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.

[0040] Furthermore, a combination of gas spraying and application of vibration to the sagger may be used as the physical impact applied by the impact applying portion.

[0041] The sagger cleaning portion 5 cleans the sagger S by removing powder, etc. of the fired material C which remains in recesses in the sagger after the majority of the fired material C has been dropped in the recovery portion 4.

[0042] There is no particular limitation as to the cleaning method provided that it enables residual powder of the fired material C to be removed, and the recesses in the sagger may be cleaned with a brush or air may be blown, for example.

[0043] It should be noted that the example of a roller hearth kiln was described in the embodiment above, but the firing apparatus of the present disclosure is not limited to roller hearth kiln, provided that it fires a starting material inside a sagger and has a recovery portion the same as the recovery portion 4, and a static furnace or a pusher furnace, etc. may also be used.

[0044] Method for Producing Fired Material

[0045] A method for producing a fired material according to an embodiment of the present disclosure comprises: a firing step in which a starting material accommodated in a sagger is fired to obtain a fired material; a turnover step in which the sagger is turned over so that an opening portion thereof is directed downward; and an impact applying step in which a physical impact is applied to the sagger having the downwardly directed opening portion and / or to the fired material accommodated in the sagger.

[0046] The method for producing a fired material can be implemented using the firing apparatus 1 described above, for example.

[0047] A starting material preparation step is carried out by mixing, etc. a plurality of starting materials, as required, and then placing the starting material ejected from a starting material supply portion of a starting material preparing portion 2 into the sagger circulating on rollers. In the firing step, the starting material accommodated in the sagger is fired to obtain the fired material. The sagger in which the starting material was placed in the starting material preparing step is conveyed to the firing portion 3 along the flow of the rollers, and passes through a passage heated by the heater, whereby the starting material is subjected to a heating treatment.

[0048] In the turnover step, the sagger is turned over so that the opening portion thereof is directed downward. The sagger accommodating the fired material obtained in the firing step is conveyed to the recovery portion 4.

[0049] When the sagger is turned over in the turnover step so that the opening portion thereof is directed downward, some of the fired material drops out, but, depending on the fired material, the whole amount thereof or a partial amount thereof may adhere to the inside of the sagger so that it does not drop out. In the impact applying step, a physical impact is therefore applied to the downwardly directed sagger and / or to the fired material accommodated in the sagger. Specific examples of the physical impact are as described above.

[0050] Apparatus for Recovering Fired Material

[0051] An apparatus for recovering a fired material according to an embodiment of the present disclosure recovers the fired material which was accommodated in the sagger, and comprises the turnover portion configured to be capable of turning over the sagger so that the opening portion thereof is directed downward, and the impact applying portion configured to be capable of applying a physical impact to the sagger having the downwardly directed opening portion and / or to the fired material accommodated in the sagger.

[0052] This recovery apparatus has the same configuration as that of the recovery portion 4 of the firing apparatus 1 disclosed above, and will therefore not be described here.

[0053] Method for Recovering Fired Material

[0054] A method for recovering a fired material according to an embodiment of the present disclosure recovers the fired material which was accommodated in the sagger, and comprises the turnover step in which the sagger is turned over so that the opening portion thereof is directed downward; and the impact applying step in which a physical impact is applied to the sagger having the downwardly directed opening portion and / or to the fired material accommodated in the sagger.

[0055] This recovery method has the same configuration as that of the recovery step of the method for producing a fired material disclosed above, and will therefore not be described here.

[0056] It should be noted that an example in which a lithium metal composite oxide is fired as the fired material has mainly been described in the present specification, but the fired material in the firing apparatus, the apparatus for recovering a fired material, the method for producing a fired material, and the method for recovering a fired material according to the present disclosure is not limited to a lithium metal composite oxide, and there is no particular limitation as to the material, which may include various types of ceramic materials and resin materials, etc. When an adhesive which bonds two solids, including the starting material, the fired material, byproducts, impurities and the sagger, is contained in the starting material or is formed as a result of the firing or a reaction; when one or more of the starting material, the fired material, byproducts and impurities reacts with the sagger; when the starting material has a small particle size and poor fluidity; or when firing is performed at a high temperature (e.g., 1000°C or more when a ceramic material is synthesized), it is difficult to recover the fired material simply by directing the opening portion of the sagger downward, but the fired material can be efficiently recovered even in such cases with the firing apparatus, the apparatus for recovering a fired material, the method for producing a fired material, and the method for recovering a fired material according to the present disclosure.

[0057] BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Figure 1 is an outline schematic diagram of a firing apparatus according to an embodiment of the present disclosure, wherein „1“ denotes firing apparatus, „2“ denotes starting material supply portion, „3“ denotes firing portion, „4“ denotes recovery portion and „5“ denotes sagger cleaning portion.

[0059] Figure 2 is an outline schematic diagram showing a turnover portion according to an embodiment of the present disclosure and a situation of deployment thereof, wherein „41“ denotes turnover portion, ,,411“ denotes support element and ,,412“ denotes rotary shaft.

[0060] EMDODIMENT

[0061] Embodiments of the present disclosure are described below, but the present disclosure is not limited in any way by the description of the embodiments and can be worked with additional modifications, as appropriate.

[0062] Embodiment 1

[0063] A firing apparatus comprising: a firing portion for firing a starting material accommodated in a sagger to obtain a fired material; and a recovery portion configured to be capable of recovering the fired material, wherein the recovery portion comprises a turnover portion configured to be capable of turning over the sagger so that an opening portion thereof is directed downward, and an impact applying portion configured to be capable of applying a physical impact to the sagger having the downwardly directed opening portion and / or to the fired material accommodated in the sagger.

[0064] Embodiment 2

[0065] The firing apparatus according to Embodiment 1 , wherein the impact applying portion is configured to be capable of spraying a gas at the opening portion of the sagger and / or at the fired material accommodated in the sagger.

[0066] Embodiment 3

[0067] The firing apparatus according to Embodiment 2, wherein the impact applying portion is configured to be capable of spraying the gas at least in the vicinity of an inner wall surface of the opening portion of the sagger. Embodiment 4

[0068] The firing apparatus according to any one of Embodiments 2 to 3, wherein the impact applying portion is configured to be capable of spraying the gas under a pressure of from 0.1 Mpa to 16 MPa.

[0069] Embodiment 5

[0070] A recovery apparatus for recovering a fired material accommodated in a sagger, the recovery apparatus comprising: a turnover portion configured to be capable of turning over the sagger so that an opening portion thereof is directed downward; and an impact applying portion configured to be capable of applying a physical impact to the sagger having the downwardly directed opening portion and / or to the fired material accommodated in the sagger.

[0071] Embodiment 6

[0072] A method for producing a fired material comprising steps of: a firing step in which a starting material accommodated in a sagger is fired to obtain a fired material; a turnover step in which the sagger is turned over so that an opening portion thereof is directed downward; and an impact applying step in which a physical impact is applied to the sagger having the downwardly directed opening portion and / or to the fired material accommodated in the sagger.

[0073] Embodiment 7

[0074] A method for recovering a fired material accommodated in a sagger comprising steps of: a turnover step in which the sagger is turned over so that an opening portion thereof is directed downward; and an impact applying step in which a physical impact is applied to the sagger having the downwardly directed opening portion and / or to the fired material accommodated in the sagger.

[0075] EXAMPLE

[0076] The present disclosure is illustrated in greater detail below using example but is not limited to these examples.

[0077] A nickel sulfate aqueous solution, and cobalt sulfate and aluminum sulfate aqueous solutions were mixed to an Ni, Co, Al ratio (molar ratio) of Ni:Co:AI= 90:5:5 to obtain a mixed aqueous solution. 10 L of pure water to which 300 g of a sodium hydroxide aqueous solution and 500 g of aqueous ammonia had been added was prepared in advance as the mother liquor in a reactor, the interior of the reactor was purged with nitrogen gas at a flow rate of 0.7 L / min to create a nitrogen atmosphere, and the reaction was also carried out under a nitrogen atmosphere.

[0078] After this, the mixed aqueous solution, sodium hydroxide aqueous solution and ammonia water were simultaneously dripped at a predetermined rate while a stirring blade was rotated at 1000 rpm, and, by means of a crystallization reaction in which the dripping amount of alkaline solution was adjusted to achieve a pH of 11.7, the Ni, Co and Al crystallized and coprecipitated so that agglomerated particles were formed, and a coprecipitate was obtained.

[0079] After this, the slurry inside the reactor was separated into liquid and solids, which were further washed with pure water to lower residual impurities, and the co-precipitate in a caked form was then dried for 10 hours at 100°C under an atmospheric environment to obtain a nickel-cobalt- aluminum composite hydroxide represented by the compositional formula Nio.9oCoo.o5Alo.o5(OH)2.

[0080] The resulting nickel-cobalt-aluminum composite hydroxide was then oxidized by a heat treatment for 6 hours at 650°C under the atmosphere (oxygen concentration: 21 vol%), and a nickel-cobalt-aluminum composite oxide was obtained.

[0081] The resulting nickel-cobalt-aluminum composite oxide and anhydrous lithium hydroxide were then weighed out to a molar ratio of Li / (Ni+Co+AI)=1.030 and mixed to obtain a mixture.

[0082] The resulting mixture was fired using the firing apparatus 1 shown in Figure 1. Specifically, 14 kg of the mixture were loaded from the starting material supply portion 2 into mullite saggers having a length of 330 mm, a breadth of 330 mm, and a height of 150 mm. After this, the saggers were conveyed to the firing portion 3 where the mixture was fired over the course of 4 hours at a maximum temperature of 740°C under an oxygen atmosphere (oxygen concentration: 97 vol%) then discharged from the firing portion 3 after cooling.

[0083] The discharged saggers were conveyed by the rollers to the recovery portion 4, after which the saggers were immobilized while being gripped from both ends thereof. The saggers were then inverted through 180° by being turned over at a rate of 40 rpm and held for 3 seconds with the opening portion thereof directed downward. The inversion and holding for 3 seconds were repeated for a total of three times.

[0084] The inversion and holding for 3 seconds were once again repeated for a total of three times in the recovery portion 4 for two saggers in which fired material remained as a result of the operation above, and, for the first two times out of the three times of holding with the opening portion directed downward, a physical impact was imparted to the fired material by blowing decarboxylated air (carbon dioxide concentration: 10 ppm or less) at a pressure of 2 MPa using an air gun having an opening diameter of 4 mm. In this process, the air was blown in the vicinity of the inner wall of the saggers. Specifically, the air was introduced into gaps formed between the fired material and the inner wall of the saggers as a result of the fired material contracting in the saggers. Virtually all of the fired material dropped out from both of the saggers as a result.

[0085] By applying an impact to the sagger and / or to the fired material accommodated in the sagger while the opening portion of the sagger is directed downward in the manner described above, it is possible to recover the fired material that could not be recovered by simply inverting the sagger.

Claims

CLAIMS1. A firing apparatus comprising: a firing portion for firing a starting material accommodated in a sagger to obtain a fired material; and a recovery portion configured to be capable of recovering the fired material, wherein the recovery portion comprises a turnover portion configured to be capable of turning over the sagger so that an opening portion thereof is directed downward, and an impact applying portion configured to be capable of applying a physical impact to the sagger having the downwardly directed opening portion and / or to the fired material accommodated in the sagger.

2. The firing apparatus according to Claim 1, wherein the impact applying portion is configured to be capable of spraying a gas at the opening portion of the sagger and / or at the fired material accommodated in the sagger.

3. The firing apparatus according to Claim 2, wherein the impact applying portion is configured to be capable of spraying the gas at least in the vicinity of an inner wall surface of the opening portion of the sagger.

4. The firing apparatus according to any one of Claims 2 to 3, wherein the impact applying portion is configured to be capable of spraying the gas under a pressure of from 0.1 Mpa to 16 MPa.

5. A recovery apparatus for recovering a fired material accommodated in a sagger, the recovery apparatus comprising: a turnover portion configured to be capable of turning over the sagger so that an opening portion thereof is directed downward; and an impact applying portion configured to be capable of applying a physical impact to the sagger having the downwardly directed opening portion and / or to the fired material accommodated in the sagger.

6. A method for producing a fired material comprising steps of: a firing step in which a starting material accommodated in a sagger is fired to obtain a fired material; a turnover step in which the sagger is turned over so that an opening portion thereof is directed downward; and an impact applying step in which a physical impact is applied to the sagger having the downwardly directed opening portion and / or to the fired material accommodated in the sagger.

7. A method for recovering a fired material accommodated in a sagger comprising steps of: a turnover step in which the sagger is turned over so that an opening portion thereof is directed downward; andan impact applying step in which a physical impact is applied to the sagger having the downwardly directed opening portion and / or to the fired material accommodated in the sagger.

Images