CN114436663A

CN114436663A - Preparation method of mullite sagger

Info

Publication number: CN114436663A
Application number: CN202110872315.5A
Authority: CN
Inventors: 黄勇; 邓孟辉; 尤英
Original assignee: Jingzhou Xinqiu Industry Co ltd
Current assignee: Jingzhou Xinqiu Industry Co ltd
Priority date: 2021-07-30
Filing date: 2021-07-30
Publication date: 2022-05-06

Abstract

The invention discloses a preparation method of a mullite sagger, belonging to the technical field of mullite sagger production, and the preparation method comprises the following steps: s1, preparation of aggregate: mixing mullite, cordierite and molekett to obtain aggregate; s2, preparation of base stock: mixing alumina powder, zircon sand, magnesite powder and quartz powder to obtain a base material; s3, preparation of slurry: mixing water, base material and binding agent to obtain slurry; s4, preparing pug: mixing the slurry and the aggregate, and treating the mixture by a kneading machine and a pug mill to obtain pug; s5, molding: pouring the pug into a forming die, and pressing to obtain a sagger; s6, drying: conveying the sagger into a drying chamber for drying; s7, sintering: and (4) feeding the dried sagger into a firing kiln for firing to obtain the mullite sagger. The invention solves the problems of poor high-temperature performance, poor thermal shock stability and poor erosion resistance of the mullite sagger and easy powder removal and slag removal.

Description

Preparation method of mullite sagger

Technical Field

The invention relates to the technical field of mullite sagger production, in particular to a preparation method of a mullite sagger.

Background

Mullite is a general name of a series of minerals composed of aluminosilicate, is a high-quality refractory raw material, and is rare. Mullite is a mineral formed by aluminosilicate at high temperature, and mullite is formed when aluminosilicate is artificially heated. The mullite can be applied to industries such as refractory materials, ceramics, metallurgy, casting, electronics and the like, has the characteristics of high temperature resistance, high strength, small heat conductivity coefficient, obvious energy-saving effect and the like, is suitable for linings of petroleum cracking furnaces, metallurgical hot blast furnaces, ceramic roller kilns, tunnel kilns, electroceramic drawer kilns, glass crucible kilns and various electric furnaces, and can be in direct contact with flame.

The mullite sagger is one of saggers, and is needed to be used in the sintering process of lithium cobaltate, cobalt oxide, ternary materials, graphite cathode materials, lithium battery anode and cathode materials and various powders. At present, a plurality of mullite saggers are prepared, but the phenomena of poor high-temperature performance, poor thermal shock stability and poor erosion resistance generally exist, and powder and slag are easy to remove.

In view of the above, the invention provides a novel preparation method of a mullite sagger.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide a preparation method of a mullite sagger, which aims to solve the problems that the mullite sagger is poor in high-temperature performance, thermal shock stability and erosion resistance, and easy to remove powder and slag.

In order to achieve the purpose, the invention provides the following technical scheme:

a preparation method of a mullite sagger comprises the following steps:

s1, preparation of aggregate: mixing mullite, cordierite and molykate according to the mass ratio of 4:3:1 to obtain aggregate;

s2, preparation of base materials: mixing alumina powder, zircon sand, magnesite powder and quartz powder according to the mass ratio of 2:1:1:1 to obtain a base material;

s3, preparation of slurry: water, base material and binding agent are mixed according to the mass ratio of 25: (8-10): 1, mixing by a mixing device to obtain slurry;

s4, preparing pug: mixing the slurry and the aggregate according to the mass ratio (1.5-3): 1, mixing, and treating by a kneading machine and a pug mill to obtain pug;

s5, molding: pouring the pug into a forming die, and then pressing according to the required size to obtain a sagger;

s6, drying: the sagger is sent into a drying chamber with the temperature of 120-150 ℃ for drying for 8-12 h;

s7, sintering: and (3) feeding the dried sagger into a firing kiln for firing, wherein the firing temperature is 1280-1400 ℃, and the heat preservation time is 4-6 hours, so as to obtain the mullite sagger.

More preferably: the binder is one or two of carboxymethyl cellulose and yellow dextrin.

More preferably: in step S3, the mass ratio of water, binder and binder is 25: 9: 1.

more preferably: in step S4, the mass ratio of the slurry to the aggregate is 2: 1.

more preferably: the mixing device comprises a stirring tank, a driving mechanism, a rotating shaft, a rotating drum, a first stirrer and a second stirrer;

the top of the stirring tank is provided with a feeding hole, the bottom of the stirring tank is provided with a discharging hole, the rotating shaft and the central shaft of the rotating drum are both superposed with the central shaft of the stirring tank, the rotating shaft is inserted into the rotating drum, the upper end of the rotating shaft extends to the upper part of the rotating drum, the first stirrer and the second stirrer are both positioned in the stirring tank, the first stirrer is fixed on the rotating drum, and the second stirrer is fixed on the rotating shaft;

the driving mechanism is used for driving the rotating shaft and the rotating drum to rotate reversely around the central shaft of the rotating drum simultaneously, so that the first stirrer and the second stirrer reversely stir materials in the stirring tank.

More preferably: the driving mechanism comprises a motor, a fixing plate, a lower rotary table, an upper rotary table and a gear;

the fixing plate is fixed at the bottom of the stirring tank, the motor is installed on the fixing plate, the gear is fixedly connected with an output shaft of the motor, the upper rotary table is positioned below the stirring tank, the lower rotary table is positioned below the upper rotary table, and central shafts of the upper rotary table and the lower rotary table are coincided with a central shaft of the stirring tank;

the gear is positioned between the upper rotary table and the lower rotary table and is respectively meshed with the tooth surfaces of the upper rotary table and the lower rotary table, the lower end of the rotating shaft is fixed with the center of the lower rotary table, and the lower end of the rotating drum is fixed with the center of the upper rotary table.

More preferably: the rotary table top surface is provided with the sand grip, the sand grip is the ring form and the centre of a circle is located on the agitator tank center pin, agitator tank bottom surface be provided with the spout of sand grip looks adaptation, the sand grip insert in the spout and with spout sliding fit.

More preferably: the rotary drum lower extreme with it is fixed to go up the carousel, and the upper end passes agitator tank bottom and extend to in the agitator tank, the pivot lower extreme with it is fixed to go down the carousel, and the upper end passes just upwards extend behind the rotary drum, the pivot surface mounting has spacing platform, spacing platform is located the rotary drum top and with rotary drum up end contact.

More preferably: the first stirrer comprises a first vertical plate, a first transverse plate and a first reinforcing rib;

one end of the first transverse plate is fixed with the outer surface of the rotary drum, the other end of the first transverse plate is fixed with the lower end of the first vertical plate, the first reinforcing rib is obliquely arranged and connected to the joint of the first vertical plate and the first transverse plate, the upper end of the first reinforcing rib is connected with the first vertical plate, and the lower end of the first reinforcing rib is connected with the first transverse plate;

the first transverse plate is close to the inner bottom of the stirring tank, and the first vertical plate is close to the inner side wall of the stirring tank.

More preferably: the second stirrer comprises a second vertical plate, a second transverse plate and a second reinforcing rib;

one end of the second transverse plate is fixed with the outer surface of the rotating shaft, the other end of the second transverse plate is fixed with the middle section of the second vertical plate, the second transverse plate is positioned above the rotating drum, the second reinforcing rib is obliquely arranged and connected at the joint of the second vertical plate and the second transverse plate, one end of the second reinforcing rib is connected with the second vertical plate, and the other end of the second reinforcing rib is connected with the second transverse plate;

the second vertical plate is connected and positioned between the first vertical plate and the rotary drum, the lower end of the second vertical plate is close to the first transverse plate, and the upper end of the second vertical plate is close to the top of the stirring tank.

In conclusion, the invention has the following beneficial effects: the mullite has excellent high-temperature mechanical property, chemical stability, creep resistance and thermal shock resistance, and the thermal expansion coefficient is low; cordierite has a small thermal expansion coefficient, and the thermal shock stability of the sagger product can be improved; the Moleksite low-density microporous material has low thermal expansion coefficient and good thermal shock resistance. The addition of the zircon sand improves the erosion resistance of the sagger, and in the invention, no matter the aggregate or the base material does not contain clay materials with higher impurity content, such as kaolin, chlorite, bentonite and the like, so the mullite sagger formed by sintering is not easy to generate the phenomena of powder removal and slag removal. The problems that the mullite sagger is poor in high-temperature performance, thermal shock stability and erosion resistance and easy to remove powder and slag are solved.

Drawings

FIG. 1 is a block flow diagram of an embodiment, primarily intended to embody a method of making a mullite sagger;

FIG. 2 is a schematic structural diagram of an embodiment, which is mainly used for embodying the overall structure of the mixing device;

FIG. 3 is a schematic sectional view of an embodiment, which is mainly used for embodying the internal structure of the mixing device;

fig. 4 is a schematic structural diagram of the embodiment, which is mainly used for embodying the structures of the first stirrer and the second stirrer.

In the figure, 1, a stirring tank; 2. a support leg; 3. a feed inlet; 4. a discharge port; 51. a motor; 52. a fixing plate; 53. a lower turntable; 54. an upper turntable; 55. a gear; 56. a convex strip; 6. a rotating shaft; 7. a rotating drum; 8. a first stirrer; 81. a first vertical plate; 82. a first transverse plate; 83. a first reinforcing rib; 9. a second agitator; 91. a second vertical plate; 92. a second transverse plate; 93. a second reinforcing rib; 10. and a limiting table.

Detailed Description

The invention is described in detail below with reference to the figures and examples.

Example 1: a method for preparing a mullite sagger, as shown in fig. 1, comprising the following steps:

s1, preparation of aggregate: mixing mullite, cordierite and molekite according to the mass ratio of 4:3:1 for 20min by a stirrer to obtain aggregate;

s2, preparation of base materials: mixing alumina powder, zircon sand, magnesite powder and quartz powder for 20min by a stirrer according to the mass ratio of 2:1:1:1 to obtain a base material;

s3, preparation of slurry: using carboxymethyl cellulose as a binding agent, and mixing water, a base material and the binding agent according to a mass ratio of 25: 9: 1, mixing for 30min by a mixing device to obtain slurry;

s4, preparing pug: and (3) mixing the slurry and the aggregate according to the mass ratio of 2:1, mixing, and stirring by a kneading machine and a pug mill to prepare pug to obtain pug;

s5, molding: pouring the pug into a forming die, and pressing by a press machine to form a sagger with the specification of 20cm multiplied by 230cm multiplied by 125 cm;

s6, drying: the sagger is sent into a drying chamber with the temperature of 130 ℃ to be dried for 10 hours;

s7, sintering: and (3) feeding the dried sagger into a firing kiln for firing, wherein the firing temperature is 1300 ℃, and the heat preservation time is 5 hours, so as to obtain the mullite sagger.

In the technical scheme, the mullite has excellent high-temperature mechanical property, chemical stability, creep resistance and thermal shock resistance, and the thermal expansion coefficient is low; cordierite has a small thermal expansion coefficient, and the thermal shock stability of the sagger product can be improved; molekett is a low-density microporous material, has low thermal expansion coefficient and good thermal shock resistance. The addition of the zircon sand improves the erosion resistance of the sagger, and in the invention, no matter the aggregate or the base material does not contain clay materials with higher impurity content, such as kaolin, chlorite, bentonite and the like, so the mullite sagger formed by sintering is not easy to generate the phenomena of powder removal and slag removal. The problems that the mullite sagger is poor in high-temperature performance, thermal shock stability and erosion resistance and easy to remove powder and slag are solved.

Referring to fig. 2 to 4, in step S3, the mixing apparatus includes a stirring tank 1, a driving mechanism, a rotating shaft 6, a rotating drum 7, a first stirrer 8, and a second stirrer 9. The stirring tank 1 is cylindrical, the top of the stirring tank is provided with a feeding hole 3, the bottom of the stirring tank is provided with a discharging hole 4, and the discharging hole 4 is positioned on one side of the lower part of the stirring tank 1. 1 bottom of agitator tank is fixed with landing leg 2, and landing leg 2 is provided with threely, and three landing leg 2 sets up in 1 bottom of agitator tank along 1 circumferencial direction of agitator tank equidistant. The upper ends of the supporting legs 2 are fixed with the bottom of the stirring tank 1, and the lower ends of the supporting legs are used for being supported on the ground or a foundation plane. The central axes of the rotating shaft 6 and the rotating drum 7 are coincided with the central axis of the stirring tank 1, the rotating shaft 6 is inserted in the rotating drum 7, and the upper end of the rotating shaft extends above the rotating drum 7. First agitator 8 and second agitator 9 all are located agitator tank 1, and first agitator 8 is fixed on rotary drum 7, and second agitator 9 is fixed on pivot 6. The driving mechanism is used for driving the rotating shaft 6 and the rotating drum 7 to rotate reversely around the central shaft at the same time, and the rotating speeds are the same, so that the first stirrer 8 and the second stirrer 9 reversely stir materials in the stirring tank 1, and the materials are conveniently and quickly mixed.

Referring to fig. 2-4, the drive mechanism preferably includes a motor 51, a fixed plate 52, a lower dial 53, an upper dial 54, and a gear 55. The fixing plate 52 is fixed at the bottom of the stirring tank 1, the motor 51 is installed on the fixing plate 52, and the gear 55 is fixedly connected with the output shaft of the motor 51 so as to drive the gear 55 to rotate around the central shaft thereof through the motor 51. The upper turntable 54 is positioned below the stirring tank 1, the lower turntable 53 is positioned below the upper turntable 54, and the central axes of the upper turntable 54 and the lower turntable 53 are coincided with the central axis of the stirring tank 1. The upper turntable 54 and the lower turntable 53 are symmetrically arranged on the upper side and the lower side of the gear 55, specifically, a circle of tooth surface matched with the gear 55 is arranged on the bottom surface of the upper turntable 54, and a circle of tooth surface matched with the gear 55 is arranged on the top surface of the lower turntable 53. The gear 55 is positioned between the upper turntable 54 and the lower turntable 53 and is respectively meshed with the tooth surfaces of the upper turntable 54 and the lower turntable 53, the lower end of the rotating shaft 6 is fixed with the center of the lower turntable 53, and the lower end of the rotating drum 7 is fixed with the center of the upper turntable 54. In order to enable the upper rotating disc 54 to rotate stably under the stirring tank 1, it is preferable that the top surface of the upper rotating disc 54 is provided with a convex strip 56, the convex strip 56 is annular, and the center of the circle is located on the central axis of the stirring tank 1. The bottom surface of the stirring tank 1 is provided with a sliding groove matched with the raised line 56, and the raised line 56 is inserted into the sliding groove and is in sliding fit with the sliding groove. The lower extreme of rotary drum 7 is fixed with last carousel 54, and in the upper end passed agitator tank 1 bottom and extended to agitator tank 1, the lower extreme of pivot 6 was fixed with lower carousel 53, and the upper end passed behind the rotary drum 7 and upwards extended. In order to enable the rotating shaft 6 to rotate stably in the rotating drum 7 and prevent the rotating shaft 6 from moving downwards in the rotating drum 7, specifically, a limiting table 10 is fixed on the outer surface of the rotating shaft 6, and the limiting table 10 is located above the rotating drum 7 and is in contact with the upper end surface of the rotating drum 7.

In the technical scheme, the traditional mixing device adopts a single stirrer for stirring, and during the stirring process of the stirrer, the stirring is carried out clockwise or anticlockwise, and the stirring cannot be carried out clockwise or anticlockwise simultaneously, so that the novel mixing device is provided, and two stirrers are adopted for carrying out reverse stirring, namely the first stirrer 8 and the second stirrer 9. In the invention, when the motor 51 is started, the gear 55 rotates between the upper rotating disc 54 and the lower rotating disc 53, and the gear 55 is respectively meshed with the tooth surfaces on the upper rotating disc 54 and the lower rotating disc 53, so that the upper rotating disc 54 and the lower rotating disc 53 rotate reversely around the central shafts thereof during the rotation of the gear 55, and the first stirrer 8 and the second stirrer 9 are driven by the rotating cylinder 7 and the rotating shaft 6 to reversely stir materials in the stirring tank 1.

Referring to fig. 1-3, the first agitator 8 preferably includes a first riser 81, a first cross plate 82, and a first reinforcement 83. One end of the first transverse plate 82 is fixed to the outer surface of the rotating drum 7, the other end of the first transverse plate 82 is fixed to the lower end of the first vertical plate 81, the first reinforcing ribs 83 are arranged in an inclined mode and connected to the joints of the first vertical plate 81 and the first transverse plate 82, the upper ends of the first reinforcing ribs 83 are connected with the first vertical plate 81, and the lower ends of the first reinforcing ribs are connected with the first transverse plate 82. First diaphragm 82 is close to the bottom in agitator tank 1, and first riser 81 is close to agitator tank 1 inside wall to through the stirring of first diaphragm 82 and first riser 81 the material that is close to agitator tank 1 lateral wall or bottom. The first stirrers 8 are arranged in two, and the two first stirrers 8 are symmetrically arranged on two opposite sides of the rotating drum 7.

Referring to fig. 2-4, the second agitator 9 preferably includes a second vertical plate 91, a second transverse plate 92, and a second reinforcing bead 93. One end of the second horizontal plate 92 is fixed to the outer surface of the rotating shaft 6, the other end of the second horizontal plate 92 is fixed to the middle section of the second vertical plate 91, and the second horizontal plate 92 is located above the rotating drum 7. The second strengthening rib 93 sets up and connects in second riser 91, second diaphragm 92 junction for the slope, and second strengthening rib 93 one end is connected with second riser 91, and the other end is connected with second diaphragm 92. The second vertical plate 91 is connected between the first vertical plate 81 and the rotating drum 7, so that the materials close to the middle part of the stirring tank 1 are stirred through the second horizontal plate 92 and the second vertical plate 91. The lower end of the second vertical plate 91 is close to the first transverse plate 82, and the upper end is close to the inner top of the stirring tank 1. The number of the second stirrers 9 is two, and the two second stirrers 9 are symmetrically arranged on two opposite sides of the rotating shaft 6.

In the above technical solution, when the rotating drum 7 rotates, the first vertical plate 81, the first horizontal plate 82 and the first reinforcing rib 83 rotate around the central axis of the rotating drum 7 as a whole, so that the materials near the side wall and the inner bottom in the stirring tank 1 are sufficiently stirred through the first vertical plate 81 and the first horizontal plate 82. When the rotating shaft 6 rotates, the second vertical plate 91, the second transverse plate 92 and the second reinforcing ribs 93 rotate integrally around the central axis of the rotating drum 7, so that materials close to the central position in the stirring tank 1 are stirred through the second vertical plate 91 and the second transverse plate 92. According to the invention, the two independent stirrers, namely the first stirrer 8 and the second stirrer 9 are used for stirring at different positions and in different directions, so that the stirring efficiency and the material mixing effect are improved.

Example 2: a method for preparing a mullite sagger, which is different from the method in example 1, and comprises the following steps:

s3, preparation of slurry: using carboxymethyl cellulose as a binding agent, and mixing water, a base material and the binding agent according to a mass ratio of 25: 8: 1, mixing for 30min by a mixing device to obtain slurry;

s4, preparing pug: mixing the slurry and the aggregate according to a mass ratio of 1.5: 1, mixing, and stirring by a kneading machine and a pug mill to prepare pug to obtain pug;

s6, drying: conveying the sagger into a drying chamber at 120 ℃ for drying for 8 hours;

s7, sintering: and (3) feeding the dried sagger into a firing kiln for firing, wherein the firing temperature is 1280 ℃, and the heat preservation time is 4 hours, so as to obtain the mullite sagger.

Example 3: a method for preparing a mullite sagger, which is different from the method in example 1, and comprises the following steps:

s2, preparation of base stock: mixing alumina powder, zircon sand, magnesite powder and quartz powder for 20min by a stirrer according to the mass ratio of 2:1:1:1 to obtain a base material;

s4, preparing pug: and (3) mixing the slurry and the aggregate according to a mass ratio of 3:1, mixing, and stirring by a kneading machine and a pug mill to prepare pug to obtain pug;

s6, drying: the sagger is sent into a drying chamber with the temperature of 150 ℃ to be dried for 12 hours;

s7, sintering: and (3) feeding the dried sagger into a firing kiln for firing at 1400 ℃, and keeping the temperature for 6 hours to obtain the mullite sagger.

The above description is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments, and all technical solutions belonging to the idea of the present invention belong to the protection scope of the present invention. It should be noted that several improvements and modifications without departing from the principle of the present invention will occur to those skilled in the art, and such improvements and modifications should also be construed as within the scope of the present invention.

Claims

1. A preparation method of a mullite sagger is characterized by comprising the following steps: the method comprises the following steps:

s6, drying: the saggar is sent into a drying chamber with the temperature of 120-150 ℃ for drying for 8-12 h;

2. The method of preparing a mullite sagger as set forth in claim 1, wherein: the binder is one or two of carboxymethyl cellulose and yellow dextrin.

3. The method of preparing a mullite sagger as set forth in claim 1, wherein: in step S3, the mass ratio of water, binder and binder is 25: 9: 1.

4. the method of preparing a mullite sagger as set forth in claim 1, wherein: in step S4, the mass ratio of the slurry to the aggregate is 2: 1.

5. the method of preparing a mullite sagger as set forth in claim 1, wherein: the mixing device comprises a stirring tank (1), a driving mechanism, a rotating shaft (6), a rotating drum (7), a first stirrer (8) and a second stirrer (9);

the top of the stirring tank (1) is provided with a feeding hole (3), the bottom of the stirring tank is provided with a discharging hole (4), the central axes of the rotating shaft (6) and the rotating drum (7) are coincided with the central axis of the stirring tank (1), the rotating shaft (6) is inserted into the rotating drum (7), the upper end of the rotating shaft extends above the rotating drum (7), the first stirrer (8) and the second stirrer (9) are both positioned in the stirring tank (1), the first stirrer (8) is fixed on the rotating drum (7), and the second stirrer (9) is fixed on the rotating shaft (6);

the driving mechanism is used for driving the rotating shaft (6) and the rotating drum (7) to rotate reversely around the central axis of the rotating shaft simultaneously so that the first stirrer (8) and the second stirrer (9) stir materials reversely in the stirring tank (1).

6. The method of preparing a mullite sagger as claimed in claim 5, wherein: the driving mechanism comprises a motor (51), a fixing plate (52), a lower rotary table (53), an upper rotary table (54) and a gear (55);

the fixing plate (52) is fixed at the bottom of the stirring tank (1), the motor (51) is installed on the fixing plate (52), the gear (55) is fixedly connected with an output shaft of the motor (51), the upper rotary table (54) is positioned below the stirring tank (1), the lower rotary table (53) is positioned below the upper rotary table (54), and the central axes of the upper rotary table (54) and the lower rotary table (53) are coincided with the central axis of the stirring tank (1);

the bottom surface of the upper rotating disc (54) is provided with a circle of tooth surface, the top surface of the lower rotating disc (53) is provided with a circle of tooth surface, the gear (55) is positioned between the upper rotating disc (54) and the lower rotating disc (53) and is respectively meshed with the tooth surfaces of the upper rotating disc (54) and the lower rotating disc (53), the lower end of the rotating shaft (6) is fixed with the center of the lower rotating disc (53), and the lower end of the rotating drum (7) is fixed with the center of the upper rotating disc (54).

7. The method of preparing a mullite sagger as claimed in claim 6, wherein: go up carousel (54) top surface and be provided with sand grip (56), sand grip (56) are the ring form and the centre of a circle is located agitator tank (1) center pin is last, agitator tank (1) bottom surface be provided with the spout of sand grip (56) looks adaptation, sand grip (56) insert in the spout and with spout sliding fit.

8. The method of preparing a mullite sagger as claimed in claim 6, wherein: the lower end of the rotary drum (7) is fixed with the upper rotary table (54), the upper end of the rotary drum penetrates through the bottom of the stirring tank (1) and extends into the stirring tank (1), the lower end of the rotary shaft (6) is fixed with the lower rotary table (53), the upper end of the rotary drum penetrates through the rotary drum (7) and extends upwards, a limiting table (10) is fixed on the outer surface of the rotary shaft (6), and the limiting table (10) is located above the rotary drum (7) and contacts with the upper end face of the rotary drum (7).

9. The method of preparing a mullite sagger as set forth in claim 8, wherein: the first stirrer (8) comprises a first vertical plate (81), a first transverse plate (82) and a first reinforcing rib (83);

one end of the first transverse plate (82) is fixed with the outer surface of the rotary drum (7), the other end of the first transverse plate is fixed with the lower end of the first vertical plate (81), the first reinforcing ribs (83) are obliquely arranged and connected to the joints of the first vertical plate (81) and the first transverse plate (82), the upper ends of the first reinforcing ribs (83) are connected with the first vertical plate (81), and the lower ends of the first reinforcing ribs are connected with the first transverse plate (82);

the first transverse plate (82) is close to the bottom in the stirring tank (1), and the first vertical plate (81) is close to the inner side wall of the stirring tank (1).

10. The method of preparing a mullite sagger as claimed in claim 9, wherein: the second stirrer (9) comprises a second vertical plate (91), a second transverse plate (92) and a second reinforcing rib (93);

one end of the second transverse plate (92) is fixed to the outer surface of the rotating shaft (6), the other end of the second transverse plate is fixed to the middle section of the second vertical plate (91), the second transverse plate (92) is located above the rotating drum (7), the second reinforcing ribs (93) are obliquely arranged and connected to the joints of the second vertical plate (91) and the second transverse plate (92), one end of each second reinforcing rib (93) is connected to the corresponding second vertical plate (91), and the other end of each second reinforcing rib is connected to the corresponding second transverse plate (92);

the second vertical plate (91) is connected between the first vertical plate (81) and the rotary drum (7), the lower end of the second vertical plate (91) is close to the first transverse plate (82), and the upper end of the second vertical plate (91) is close to the inner top of the stirring tank (1).