Cement clinker manufacturing method and clay slurry supply device

Abstract

To provide a method for producing a cement clinker, capable of stably utilizing a clay slurry in a storage part while controlling solid particle deposition in the storage part.SOLUTION: A method for producing a cement clinker is provided which includes: a discharging step of discharging a clay slurry into a clay slurry S stored in a storage part 10, from a discharge port 28 at a bottom part 15 of the storage part 10 of the clay slurry S, the clay slurry S containing clay attached to limestone and water; a feeding step of feeding the clay slurry from the storage part 10 to a raw material mill; and a firing step of firing, in a kiln, at least a portion of a milled product obtained in the raw material mill.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a method for producing cement clinker and a clay slurry supply device. [Background technology]

[0002] Limestone is used as the main raw material for cement clinker. Some limestone has clay attached to its surface. When such limestone with clay attached is washed, clay slurry is produced. Effective use of such clay slurry as a cement raw material has been studied. For example, Patent Document 1 proposes that the solid particles of the clay slurry are allowed to settle and thicken in a gravity settling tank, and then the thickened slurry extracted from the bottom of the gravity settling tank is supplied to a cement raw material grinding device. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-143797 Summary of the Invention [Problem to be solved by the invention]

[0004] The clay slurry produced during the limestone washing process is temporarily stored in a storage area such as a pit. When the clay slurry is stored in such a storage area, the solid particles contained in the clay slurry tend to accumulate at the bottom of the storage area. As the amount of accumulated solid particles increases, it becomes difficult to transport the clay slurry from the storage area. To resolve this phenomenon, it is necessary to periodically collect the solid particles accumulated at the bottom of the storage area using a suction truck or the like.

[0005] Therefore, the present disclosure provides a method for producing cement clinker that can stably utilize the clay slurry in the storage unit while suppressing the accumulation of solid particles in the storage unit, and also provides a slurry supply device that can stably supply the clay slurry while suppressing the accumulation of solid particles in the storage unit. [Means for solving the problem]

[0006] In one aspect, the present disclosure provides a method for producing cement clinker, comprising: a discharge step of discharging clay slurry containing clay and water adhered to limestone from a discharge port at the bottom of the storage section into clay slurry stored in the storage section; a supply step of supplying the clay slurry from the storage section to a raw material mill; and a firing step of firing at least a portion of the pulverized material obtained in the raw material mill in a kiln.

[0007] The above-mentioned manufacturing method includes a discharge step of discharging clay slurry from a discharge port at the bottom of the storage section into clay slurry stored in the storage section. In this discharge step, the clay slurry remaining at the bottom is agitated by the clay slurry discharged from the discharge port. Therefore, accumulation of solid particles of the clay slurry at the bottom can be suppressed. The clay slurry supplied to the raw material mill from a storage section having such a discharge port has sufficiently reduced variation in solid particle concentration. Therefore, clogging of piping, etc. is suppressed when such clay slurry is supplied to the raw material mill, and the clay slurry can be stably supplied to the raw material mill. Therefore, according to the above-mentioned manufacturing method, the accumulation of solid particles in the storage section can be suppressed and the clay slurry can be stably supplied to the raw material mill, thereby enabling the raw material mill to be operated stably and cement clinker to be stably produced.

[0008] The storage section has a sidewall and a bottom surface at the lower end of the sidewall, and preferably multiple clay slurry discharge ports are arranged along the sidewall. Solid particles in clay slurry tend to accumulate in areas where the flow is stagnant. However, by arranging multiple discharge ports along the sidewall, it is possible to prevent solid particles from accumulating in corners near the connection between the sidewall and the bottom surface. This reduces the frequency of solid particle recovery work and improves workability.

[0009] When viewed in a vertical cross section of the clay slurry passing through the discharge port, the downward vertical direction is 0°, the horizontal direction toward the center of the storage section is 90°, and the discharge angle from the discharge port is θ, it is preferable that the discharge port discharge the clay slurry so that 0°<θ≦90° is satisfied. This allows the clay slurry to flow along the bottom of the storage section. Therefore, the accumulation of solid particles at the bottom of the storage section can be further suppressed.

[0010] In the above manufacturing method, it is preferable to suck the clay slurry from the storage section with a sand pump, supply a portion of the sucked clay slurry to the raw material mill, and discharge another portion of the sucked clay slurry from the discharge port to the storage section for circulation. The sand pump can be installed inside the storage section. This makes it possible to shorten the distance between the sand pump and the discharge port, and to sufficiently increase the discharge pressure of the clay slurry from the discharge port. In addition, the amount of clay slurry supplied to the raw material mill and the amount of clay slurry circulated can be easily adjusted depending on the properties of the clay slurry being stored. This allows for more stable use of the clay slurry.

[0011] It is preferable to use multiple flow paths to circulate the clay slurry sucked by the sand pump to the reservoir. This reduces the difference in discharge pressure between the most upstream and most downstream outlets. It also increases the average discharge pressure at each outlet. Therefore, the deposition of solid particles over a wider area can be adequately suppressed.

[0012] In the above manufacturing method, the clay slurry is preferably supplied to one or both of the raw material charging chute and raw material charging gate of the raw material mill. This allows the solid particles of the clay slurry to be effectively used as a raw material for cement clinker. Furthermore, the amount of industrial water consumed in the raw material mill along with the clay slurry can be reduced.

[0013] In one aspect, the present disclosure provides a clay slurry supplying device to be installed in a cement clinker manufacturing facility, the clay slurry supplying device comprising: a washing section for obtaining a clay slurry containing clay and water that has adhered to limestone; a storage section for storing the clay slurry; a discharge section provided at the bottom of the storage section for discharging the clay slurry into the clay slurry stored in the storage section; and a supply section for supplying the clay slurry in the storage section to a raw material mill.

[0014] The clay slurry supply device is provided with a discharge section that is provided at the bottom of the storage section and that discharges clay slurry into the clay slurry stored in the storage section. The clay slurry at the bottom of the storage section is agitated by the clay slurry discharged from this discharge section. Therefore, it is possible to suppress the accumulation of solid particles of the clay slurry at the bottom. Furthermore, the clay slurry supplied from the storage section to the raw material mill has a sufficiently reduced variation in the concentration of solid particles. Therefore, it is possible to suppress the blockage of piping, etc. in the supply section, and to reduce the variation in the properties of the clay slurry supplied to the raw material mill. Therefore, the supply device can stably supply clay slurry while suppressing the accumulation of solid particles in the storage section. [Effects of the Invention]

[0015] A method for producing cement clinker that can stably utilize the clay slurry in the storage unit while suppressing the accumulation of solid particles in the storage unit can be provided. Also, a slurry supply device that can stably supply the clay slurry while suppressing the accumulation of solid particles in the storage unit can be provided. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 is a diagram showing an example of a clay slurry supply device. [Figure 2] FIG. 2 is a plan view of the storage section of FIG. 1. [Figure 3] FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2. [Figure 4] FIG. 4 is an enlarged cross-sectional view showing the clay slurry discharge port and its vicinity in FIG. 3. [Figure 5] FIG. 10 is a diagram showing a modified example of a clay slurry supply device. [Figure 6] FIG. 1 is a diagram showing an example of a raw material mill to which a clay slurry is supplied. DETAILED DESCRIPTION OF THE INVENTION

[0017] An embodiment of the present disclosure will be described below, with reference to the drawings as needed. However, the following embodiment is an example for explaining the present disclosure and is not intended to limit the present disclosure to the following content. In the description, the same elements or elements having the same functions will be designated by the same reference numerals, and redundant explanations will be omitted where appropriate. Furthermore, unless otherwise specified, positional relationships such as up, down, left, and right will be based on the positional relationships shown in the drawings. Furthermore, the dimensional ratios of each element are not limited to those shown in the drawings.

[0018] A method for producing cement clinker according to one embodiment includes the following steps: a washing step of washing limestone having clay attached to its surface with water to obtain a clay slurry containing clay and water; an introduction step of introducing the clay slurry obtained in the washing step into a storage section; a discharge step of discharging the clay slurry from a discharge port at the bottom of the storage section into the clay slurry stored in the storage section; a supply step of supplying the clay slurry from the storage section to a raw material mill; and a firing step of firing at least a portion of the pulverized material obtained in the raw material mill in a kiln. The washing step, introduction step, discharge step, and supply step can be performed using a clay slurry supplying device shown in FIGS. 1 to 5, for example.

[0019] The clay slurry supply device illustrated in FIG. 1 includes a washing unit 60 that performs a washing process. The limestone 68 having clay attached to its surface can be limestone used as a raw material for producing cement clinker. In the washing process, the limestone 68 having clay attached to its surface is transported by belt conveyors 61 and 62 in a direction from left to right in FIG. 1. In the washing unit 60, the limestone 68 being transported is washed by spraying water from a water spray unit 65. This washes away the clay attached to the limestone, generating clay slurry.

[0020] Additionally, clay 63 adheres to the surface of the belt conveyor 61 as the limestone 68 is transported. The clay 63 adhering to the belt surface is scraped off, for example, by a belt cleaner 64 provided on the return side of the belt conveyor 61 (the return line after the belt conveyor 61 transports the raw materials). The scraped off clay containing water may also be made into clay slurry.

[0021] In this way, a clay slurry containing clay and water is obtained in the washing step. The limestone from which the clay has been washed away by washing may be introduced into, for example, a raw material mill. Meanwhile, the clay slurry may be collected in a hopper 66 as shown in FIG. 1. In order to adjust the viscosity of the clay slurry in the hopper 66, water may be introduced to dilute the clay slurry as needed.

[0022] In the introduction step, the clay slurry S obtained in the washing step is transported by a transport facility 70 equipped with a pump, piping, etc., and introduced into the storage unit 10 through the introduction piping 71 shown in Figures 2 and 3. The storage unit 10 may be, for example, a collection tank installed on the ground, or a pit formed by excavating the ground. In the manufacturing method of this embodiment, the clay slurry does not need to be extracted downward from the bottom of the storage unit by gravity, which allows for a wider range of options for the installation location of the storage unit. Furthermore, the cost of introducing the equipment is reduced and maintenance work can be performed efficiently.

[0023] In the discharge step, as shown in Figures 2 and 3, with the clay slurry S stored in the storage section 10, the clay slurry is discharged from a discharge port 28 of a circulation pipe 26 arranged at the bottom 15 of the storage section 10 into the clay slurry S stored in the storage section 10. The bottom in the present disclosure refers to a region below a height that is 1 / 3 of the maximum height (maximum height) when the level when the maximum amount of clay slurry S is stored in the storage section 10 is used as a reference. The maximum height may be 1 to 10 m, or may be 2 to 5 m.

[0024] The storage section 10 has a side wall 14 and a bottom surface 12 at the lower end of the side wall 14. The discharge port 28 discharges the clay slurry toward the side wall 14 opposite to the side wall 14 closer to the discharge port 28. The discharge port 28 may discharge the clay slurry toward the center of the storage section 10. This allows the clay slurry S to flow toward the sand pump 20.

[0025] A plurality of discharge ports 28 for discharging the clay slurry are provided so as to surround the sand pump 20, which will be described later, in a plan view as shown in Fig. 2. The discharge ports 28 are provided closer to the side wall 14 than the sand pump 20. This allows the area in which the deposition of solid particles can be suppressed to be sufficiently wide.

[0026] The plurality of discharge ports 28 may be arranged at predetermined intervals along the side wall 14. By arranging a plurality of ports along the side wall 14 in this manner, it is possible to maintain the flow of the clay slurry S at the corners near the connection between the side wall 14 and the bottom surface 12, and to prevent the solid particles contained in the clay slurry S from settling. The number and intervals of the discharge ports 28 are not limited to the example shown in the figure, and may be changed depending on the shape and size of the storage section 10, the properties of the clay slurry S, etc.

[0027] A sand pump 20 is provided in the center of the bottom surface 12 of the storage unit 10 to discharge the clay slurry S from the storage unit 10. The sand pump 20 may be provided with, for example, an agitating blade at the bottom. By providing such an agitating blade, the solid particles contained in the clay slurry can be crushed at the suction port. Furthermore, by continuously agitating the clay slurry, the accumulation of solid matter near the suction port can be suppressed. In this way, the clay slurry containing solid particles can be stably sucked.

[0028] The clay slurry S sucked into the sand pump 20 flows through the outlet pipe 22 and branches into two at the branch point 25. The branch point 25 may be, for example, a three-way valve. A portion of the clay slurry S separated at the branch point 25 is supplied to the raw material mill, and another portion flows through the circulation pipe 26 and is circulated and supplied to the storage unit 10. When the clay slurry is circulated and supplied to the storage unit 10 in this manner, the clay slurry is discharged from the discharge port 28 provided in the circulation pipe 26 into the clay slurry S stored in the storage unit 10. The flow rate ratio of the clay slurry circulated to the storage unit 10 via the circulation pipe 26 to the total amount of clay slurry sucked into the sand pump 20 is preferably 0.05 to 0.5, and more preferably 0.1 to 0.4. This allows the clay slurry to be transported with sufficiently high efficiency while suppressing the deposition of solid particles.

[0029] A portion of the clay slurry sucked into the sand pump 20 is discharged from the discharge port 28. The transport distance of the clay slurry from the sand pump 20 to the discharge port 28 can be made sufficiently short. Therefore, the discharge pressure of the clay slurry from the discharge port 28 can be made sufficiently higher than when the clay slurry is discharged from, for example, the inlet pipe 71. Therefore, the deposition of solid particles in the storage section 10 can be sufficiently suppressed without, for example, increasing the size of the pump in the transport equipment 70. The amount of clay slurry discharged from the discharge port 28 can be adjusted by changing the amount of clay slurry circulated.

[0030] 3 indicate the distance between the side wall 14 and the portion of the circulation pipe 26 where the discharge port 28 is provided, and the distance between the portion and the bottom surface 12. Distance L1 may be 0.5 m or less, or may be 0.2 m or less. Distance L2 may be 0.5 m or less, or may be 0.2 m or less.

[0031] FIG. 4 shows a vertical cross section passing through the discharge port 28 formed in the circulation pipe 26. The discharge port 28 discharges the circulated clay slurry. The discharge direction D of the clay slurry from the discharge port 28 is defined as the direction of a straight line connecting the center C1 of the circulation pipe 26 to the center C2 of the discharge port 28. The discharge angle θ of the clay slurry from the discharge port 28 is defined as the angle between the vertical downward direction D1 and the discharge direction D, with the vertical downward direction D1 as the reference, when the vertical downward direction D1 is 0° and the horizontal direction D2 toward the center of the storage section 10 is 90°. In other words, when the discharge angle θ is 0°, the clay slurry discharge port 28 discharges the clay slurry toward the bottom surface 12. On the other hand, when the discharge angle θ is 90°, the clay slurry discharge port 28 discharges the clay slurry in the horizontal direction toward the center of the storage section 10.

[0032] From the viewpoint of sufficiently suppressing deposition of solid particles of the clay slurry in the storage section 10, the discharge angle θ is preferably 0°<θ≦90°. This causes the clay slurry to flow from one side wall 14 of the storage section 10 toward the opposing side wall 14 and along the bottom surface 12 of the storage section 10. This makes it possible to sufficiently suppress deposition of solid particles in the storage section 10. From the same viewpoint, the discharge angle θ is preferably 30°≦θ<≦90°, more preferably 60°≦θ<90°, and even more preferably 70°≦θ<90°.

[0033] The discharge directions D from the multiple discharge ports 28 do not all need to be the same, and may be different from one another. In addition, the discharge direction D may be offset from the opposing direction of the opposing side walls 14. For example, when viewed in a plan view as shown in FIG. 2, the discharge direction D may be offset from the opposing direction of the side walls 14 (for example, D AThe discharge ports 28 may be formed in a direction parallel to the sand pump 20 (i.e., a direction parallel to the sand pump 20). This can prevent solid particles from accumulating in the area between adjacent discharge ports 28. In one example, the clay slurry may be discharged from the discharge ports 28 in such a way that a vortex is formed with the sand pump 20 as its center. This allows the accumulated solid particles to be caught in the vortex and smoothly sucked into the sand pump 20. If a vortex is formed in the reservoir 10 with the suction of the sand pump 20 and the discharge direction of the clay slurry discharged from the discharge ports 28 acting synergistically, the accumulation of solid particles can be further prevented.

[0034] In a modified example, the clay slurry may be branched into three or more paths at the branching section. In this case, multiple circulation pipes 26 may be provided, and the clay slurry may be circulated to the reservoir 10 via multiple circulation routes. In the example shown in FIG. 5, the clay slurry branches into three paths at the branching section 25A. Two of these paths are composed of a first circulation pipe 26A and a second circulation pipe 26B. In this case, the clay slurry sucked by the sand pump 20 is branched at the branching section 25A, and then circulated to the reservoir 10 via two paths (two routes), the first circulation pipe 26A and the second circulation pipe 26B.

[0035] The first circulation pipe 26A and the second circulation pipe 26B are each provided with a discharge port 28, similar to the circulation pipe 26 in FIGS. 2 and 3. In this case, the flow path length between the most upstream discharge port 28 and the most downstream discharge port 28 can be made shorter than the flow path length in the circulation pipe 26 in FIG. 2. This reduces the difference in discharge pressure between the most upstream discharge port 28 and the most downstream discharge port 28. Furthermore, when there is only one circulation pipe 26, the flow rate of the clay slurry circulating at the downstream discharge port 28 decreases, and the flow pressure decreases. This also reduces the discharge pressure from the discharge port 28. On the other hand, when there are multiple circulation pipes 26, the flow pressure is maintained high, and the discharge pressure from the discharge port 28 can be maintained high. This allows the clay slurry S in the storage section 10 to be sufficiently agitated, thereby sufficiently suppressing the deposition of solid particles over a wider area.

[0036] In the supply step, a portion of the clay slurry discharged from the storage section 10 is supplied to the raw material mill. In the example of Figures 2 and 3, the clay slurry discharged by the sand pump 20 flows through the discharge pipe 22 and then branches into two at the branch section 25. One of the two clay slurries separated at the branch section 25 flows through the supply pipe 27 and is supplied to the raw material mill.

[0037] In the example shown in FIG. 6, the raw material mill 50 includes a raw material charging gate 51 through which the cement raw materials are introduced, a raw material charging chute 52 connecting the raw material charging gate 51 to the mill main body 54, and the mill main body 54. Clay slurry circulating through the supply pipe 27 is supplied to one or both of the raw material charging gate 51 and the raw material charging chute 52. This prevents the cement raw materials from adhering to the raw material charging gate 51 and the raw material charging chute 52. The introduction of the clay slurry also cools the gas discharged from the raw material mill 50. Kiln exhaust gas at 200 to 400°C is introduced into the mill main body 54 through a gas flow path 56. This kiln exhaust gas exchanges heat with the cement raw materials before being discharged from the mill main body 54. The gas discharged from the discharge pipe 55 connected to the mill main body 54 contains pulverized material. This pulverized material is separated from the gas by a cyclone and an electrostatic precipitator connected to the discharge pipe 55.

[0038] The pulverized material separated from the gas by the cyclone is fired in a kiln as a cement raw material together with other raw materials in the firing process. An electrostatic precipitator installed downstream of the cyclone collects dust (fine particles) that could not be separated by the cyclone. When the gas temperature during dust collection is between 100°C and 200°C, the dust's electrical resistance increases, tending to reduce the dust collection efficiency in the electrostatic precipitator. Therefore, to improve dust collection efficiency, it is preferable to cool the gas discharged from the raw material mill 50 to 70°C to 90°C. Therefore, by supplying clay slurry to the raw material input gate 51 and the raw material input chute 52, the dust-containing gas discharged from the raw material mill 50 can be sufficiently cooled. Water, such as industrial water, may be used in addition to the clay slurry for cooling. In this case, using clay slurry reduces water consumption while effectively utilizing solid particles as a cement raw material.

[0039] In the firing process, the pulverized material (dust) collected by the cyclone and electrostatic precipitator is fired in a kiln together with other raw materials as cement raw materials. The kiln may be a kiln equipped with a new suspension preheater. Cement clinker is obtained by firing in such a kiln and cooling in a clinker cooler. According to the method for producing cement clinker of this embodiment, the clay slurry is discharged from the discharge port 28, which makes it possible to suppress the accumulation of solid particles in the storage section 10. Furthermore, it is possible to reduce variations in the concentration of solid particles in the clay slurry S stored in the storage section 10. In this way, cement clinker can be stably produced while effectively utilizing the clay slurry from the storage section 10.

[0040] A clay slurry supply device according to one embodiment is provided in a cement clinker manufacturing facility and comprises a washing section 60 for obtaining clay slurry containing clay and water that has adhered to limestone 68, a storage section 10 for storing the clay slurry, a discharge port 28 provided at the bottom of the storage section 10 for discharging the clay slurry into the clay slurry S stored in the storage section 10, and a supply section for supplying the clay slurry S in the storage section 10 to a raw material mill 50.

[0041] The supply unit includes a sand pump 20 that discharges the clay slurry S from the storage unit 10, and a supply pipe 27 that supplies a portion of the clay slurry S discharged by the sand pump 20 to the raw material mill 50. Another portion of the clay slurry S discharged by the sand pump 20 returns to the circulation pipe 26 provided with a discharge outlet 28, and is circulated from the discharge outlet 28 to the storage unit 10. The details of the components provided in the clay slurry supply device are the same as those described above in the method for producing cement clinker. The details of the clay slurry supply device are also applied to the method for producing cement clinker.

[0042] The clay slurry supplying device can stably supply clay slurry while suppressing the accumulation of solid particles in the storage section 10. If a cement clinker manufacturing apparatus is equipped with such a clay slurry supplying device, cement clinker can be stably manufactured while effectively utilizing the solid particles contained in the clay slurry. The clay slurry supplying device does not need to have a scraper in the storage section 10. This can reduce the cost of installing the device, as well as the maintenance work and costs.

[0043] Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above embodiments. For example, the method for producing cement clinker may be performed using an apparatus having a structure different from that of the clay slurry supply apparatus and raw material mill shown in Figures 1 to 6. Furthermore, the clay slurry may contain clay or other solid particles different from the clay attached to the limestone. The storage section for the clay slurry S in the storage section is not limited to a rectangular parallelepiped shape, but may be cylindrical or have other shapes. [Example]

[0044] Example 1 A clay slurry supplying device having the configuration shown in Figures 1 to 4 was operated. As a result, for more than two months after the start of operation, the sand pump 20 installed in the center of the storage section 10 was able to continue operating without any clay recovery work being performed in the storage section 10 (storage tank). In addition, neither the supply pipe nor the circulation pipe that supplies the clay slurry to the raw material mill shown in Figure 6 was clogged. Therefore, the clay slurry in the storage section could be stably used while suppressing the accumulation of solid particles in the storage section 10.

[0045] (Comparative Example 1) Instead of installing a sand pump, a pump installed outside the storage section was used to extract the entire amount of clay slurry without circulating it and supply it to the raw material mill. In this case, solid particles accumulated in the storage section (storage tank), so it was necessary to use a suction truck to collect the solid particles that had accumulated at the bottom of the storage section at least once a month. [Industrial Applicability]

[0046] According to the present disclosure, it is possible to provide a method for producing cement clinker that can stably use clay slurry from a reservoir while suppressing the accumulation of solid particles in the reservoir, and a slurry supply device that can stably supply clay slurry while suppressing the accumulation of solid particles in the reservoir. [Explanation of symbols]

[0047] 10...storage section, 12...bottom, 14...side wall, 15...bottom, 20...sand pump, 22...exhaust pipe, 25, 25A...branch section, 26...circulation pipe, 26A...first circulation pipe, 26B...second circulation pipe, 27...supply pipe, 28...discharge port, 50...raw material mill, 51...raw material input gate, 52...raw material input chute, 54...mill main body, 55...exhaust pipe, 56...gas flow path, 60...cleaning section, 61, 62...belt conveyor, 63...clay, 64...belt cleaner, 65...spray section, 66...hopper, 68...limestone, 70...conveying equipment, 71...inlet pipe, S...clay slurry, θ...discharge angle.

Claims

1. A discharge step of suctioning the clay slurry stored in a clay slurry storage section containing clay and water attached to limestone with a sand pump, and discharging a portion of the suctioned clay slurry from a discharge port at the bottom of the storage section into the clay slurry stored in the storage section and circulating it; A supply step of supplying another portion of the clay slurry sucked by the sand pump to a raw material mill; and a calcination step of calcining at least a portion of the pulverized material obtained in the raw material mill in a kiln.

2. The storage section has a side wall and a bottom surface at a lower end of the side wall, The method for producing cement clinker according to claim 1 , wherein a plurality of the clay slurry discharge ports are arranged along the side wall.

3. 3. The method for producing cement clinker according to claim 1, wherein, when viewed in a vertical cross section of the clay slurry passing through the discharge outlet, the vertically downward direction is 0°, the horizontal direction toward the center of the storage section is 90°, and the discharge angle from the discharge outlet is θ, the discharge outlet discharges the clay slurry so that 0°<θ≦90° is satisfied.

4. A method for producing cement clinker as described in any one of claims 1 to 3, wherein in the discharge process, a portion of the sucked clay slurry is discharged into the clay slurry stored in the storage section from the discharge outlets, which are provided in multiple locations surrounding the sand pump in a plan view of the storage section, and circulated.

5. The method for producing cement clinker according to any one of claims 1 to 4, wherein a portion of the clay slurry sucked by the sand pump is circulated to the storage section using a plurality of flow paths.

6. The method for producing cement clinker according to any one of claims 1 to 5, wherein the clay slurry is supplied to one or both of a raw material charging chute and a raw material charging gate of the raw material mill.

7. A clay slurry supply device provided in a cement clinker manufacturing facility, a washing section for obtaining a clay slurry containing clay adhering to the limestone and water; A storage unit for storing the clay slurry; a sand pump provided in the storage section and configured to suck the clay slurry stored in the storage section; A discharge port provided at the bottom of the storage section, which discharges and circulates a portion of the clay slurry sucked by the sand pump into the clay slurry stored in the storage section; A clay slurry supply device comprising: a supply unit that supplies another portion of the clay slurry sucked by the sand pump to a raw material mill.

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