JP5724724B2 - Cement manufacturing apparatus and cement manufacturing method - Google Patents

Description

  The present invention relates to a cement manufacturing apparatus and a cement method, and in particular, in a cement manufacturing apparatus using solid waste as a part of cement raw material or fuel, metals can be efficiently removed from the solid waste, and The present invention relates to a cement manufacturing apparatus and the like that can reduce the burden on the apparatus.

  Conventionally, for example, Patent Document 1 discloses a cement manufacturing apparatus in which waste stones discharged from a vertical mill are returned to the vertical mill again via a circulation unit. In recent years, from the viewpoint of environmental measures and the like, it has been proposed to use solid waste such as construction residual soil and sludge as a part of cement raw material and fuel.

JP-A-5-245405

  By the way, when using solid waste as a part of cement raw material or fuel as described above, it is desirable to separate and remove metals from the solid waste. As one method for realizing this, for example, it is conceivable to dispose metal separation means on the upstream side of the vertical mill and separate and remove the metal using this. However, in the case of this configuration, when the metals cannot be sufficiently removed by the metal separation means, the metals are supplied to downstream devices such as a vertical mill, thereby causing significant damage and wear. There is a fear. In particular, when the solid waste contains a lot of moisture, the above problem becomes more prominent because the removal efficiency of the metal separation means is lowered.

  The present invention has been made in view of the problems as described above, and its purpose is to use solid waste as a part of cement raw material or fuel, and from such waste, metals containing non-ferrous metals are used. An object of the present invention is to provide a cement manufacturing apparatus and the like that can be efficiently removed and that can reduce the burden on the apparatus.

The cement manufacturing apparatus of the present invention for solving the above problems is as follows.
In cement production equipment that uses waste as cement raw material or fuel,
A pulverizing unit for pulverizing the waste, and a shape selecting unit for selecting the pulverized waste from suitable waste of a size suitable for cement raw material or fuel and other waste of other sizes. Vertical mill,
The separate waste is circulated by unloading from the shape sorting unit, and recirculating to the vertical mill;
A metal sorting section for sorting metals from the separate waste,
The circulation unit includes a discharge path for carrying out the separate waste from the vertical mill, and a supply path connected to the discharge path and supplying the separate waste vertically above the vertical mill. ,
The metal sorting unit is provided in the supply path, sorts and removes the metals from another waste conveyed by the supply path,
The supply path is provided with a plurality of systems, and includes (i) a selection system provided with the metal selection unit, and (ii) a non-selection system other than the selection system,
further,
A vibration detector for detecting vibration of the vertical mill;
Switching means for supplying the separate waste to the selected system and supplying the separate waste to the selected system when the detected vibration exceeds a threshold value. A cement manufacturing apparatus comprising:

  According to the present invention, since the metal sorting unit is provided in the circulation unit, the metals can be efficiently removed and damage to the vertical mill and the device provided downstream thereof can be reduced ( Details will be described later in [Description of Embodiments]. Furthermore, since the separate waste is supplied to the sorting system only when the vibration of the vertical mill exceeds a predetermined threshold value, the life of the sorting system can be extended. it can.

  According to the present invention, in a cement manufacturing apparatus using solid waste as part of cement raw material or fuel, it is possible to efficiently remove metals from the waste and to reduce the burden on the apparatus. A manufacturing apparatus and a cement manufacturing method can be provided.

It is a figure which shows typically the structure of the cement manufacturing apparatus of one form of this invention. It is a longitudinal cross-sectional view which shows the structure of a vertical mill. It is a perspective view of a metal sorter. It is a flowchart which shows an example of operation | movement of the circulation part mainly of the cement manufacturing apparatus of FIG. It is a flowchart which shows the other example of operation | movement of the circulation part mainly of the cement manufacturing apparatus of FIG.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
As shown in FIG. 1, the cement manufacturing apparatus 1 includes a vertical mill 100 for crushing supplied raw cement raw material and solid waste (hereinafter also simply referred to as “raw raw material etc.”), and the vertical mold A supply unit 200 for supplying the raw raw stone or the like to the mill 100, fine powder such as raw raw stone or the like crushed by the vertical mill 100 is supplied to a kiln (not shown) of a cement baking apparatus, and gas from the vertical mill 100 is supplied. A discharge unit 400 that removes dust and discharges, and a circulation unit 300 that circulates coarse particles (also referred to as waste stone or another waste) crushed by the vertical mill 100 and returns to the vertical mill 100 again. I have.

  In FIG. 1, a state in which raw raw cement material and waste are supplied to a belt conveyor 208 (detailed below) of the supply unit 200 is illustrated. Examples of the “waste (solid waste)” include construction residual soil, landfill, incineration ash, and coal ash. As an example, the “raw raw material of cement” may be a cement raw material mainly composed of limestone, clays, and silica.

[Vertical mill]
As shown in FIG. 2, the vertical mill 100 includes a cylindrical main body 141, and a crushing part 120 for crushing raw raw stone or the like is provided therein. A raw material supply path 122 extending in the vertical direction is provided on the side of the main body 141, and raw material or the like is supplied into the main body 141 through the raw material supply path 122.

  The crushing unit 120 is located at the bottom of the main body 141, and includes a crushing table 121B that rotates around the vertical axis using the electric motor 127 as a driving source, and a plurality of crushing rollers 121A that roll on the upper surface. The raw raw material or the like supplied into the main body 141 is supplied onto the crushing table 121B and is crushed by the crushing roller 121A while rotating on the crushing table 121B.

  A gas inlet 124 is provided on the bottom side surface of the main body 141, and a high-temperature gas (for example, 300 ° C.) is introduced into the main body 141 from the gas inlet 124. The introduced gas becomes an ascending gas flow 129 in the main body 141, and the ascending gas flow 129 causes fine powders such as crushed raw stones to fly upward (details will be described later). The fine powder is discharged together with the gas from the discharge port 125 at the top of the main body 141.

  An opening 126 for stone removal is provided around the crushing table 121B. Relatively large coarse particles or lumps (including metals) that cannot get on the rising gas 129 fall from the periphery of the crushing table 121B to the opening 126. Coarse particles (stone waste, separate waste) that have fallen into the opening 126 are conveyed to the outside by a belt conveyor 305 (see FIG. 1). The crushing table 121B functions as a shape selection unit in combination with the action of the rising gas flow 129.

  A classifier 123, which is another shape selection unit, is provided in the upper part of the main body 141. The classifier 123 classifies the fine powder carried by the rising gas flow 129.

[overall structure]
Refer to FIG. 1 again. The supply unit 200 receives a raw cement raw material and waste and conveys the raw material belt conveyor 208, a magnetic separator 203 disposed in the middle of the belt conveyor 208, and a raw material disposed on the terminal end side of the belt conveyor 208. A tank 202 and a raw material belt feeder 207 for conveying raw raw stones and the like from the raw material tank 202 to the vertical mill 100 are provided. Thus, when the magnetic separator 203 is provided in the supply part 200, before supplying to the raw material tank 202, an iron piece etc. are preferable from the point which can be removed.

  The discharge unit 400 includes a cyclone 409 that sends fine powder discharged from the discharge port 125 (see FIG. 2) of the vertical mill 100 to a kiln (not shown) of the cement manufacturing apparatus, and an exhaust fan 410 through which gas from the cyclone 409 passes. And an electric dust collector 411 that removes foreign matters in the gas, and a chimney 412 that discharges the gas from the dust collector 411 to the atmosphere.

  The circulation unit 300 includes a stone removal belt conveyor 305 that conveys the stone discharged from the vertical mill 100 in a substantially horizontal direction, and a stone removal bucket elevator 306 that conveys the stone discharged by the belt conveyor 305 upward. have. In the vicinity of the discharge portion of the waste stone bucket elevator 306, switching means 332 for receiving the waste stone from the waste stone bucket elevator 306 is disposed. The switching unit 332 has a function of switching the waste stone between the first transport route and the second transport route. A metal sorting unit 350 (detailed below) and a belt conveyor 370 are arranged in parallel downstream of the switching unit 332, and the switching unit 332 distributes the waste stone to one of these routes. The switching unit 332 may have any configuration as long as it has such a distribution function. As an example, the internal passage is switched by a predetermined drive source, and the stone is discharged through the first route or the second route. It may be distributed to the route.

[Metal sorter]
Next, the metal sorter 350 will be described with reference to FIG.
A commercially available metal sorting unit 350 (for example, “Multi Sorter F600” manufactured by Earth Technica Co., Ltd.) can be used. In this example, a belt conveyor 354 that conveys the waste stones in a substantially horizontal direction, and two hoppers 364 and 365 provided near the end of the belt conveyor 354 are provided. The side closer to the belt conveyor 354 is a first hopper 365 and the side far from the belt conveyor 354 is a second hopper 365. The metal sorting unit 350 further includes a magnetic field sensor 353 disposed in the belt conveyor 354. In addition, air nozzles 356 arranged in the lateral direction are provided between the end portion of the belt conveyor 354 and the first hopper 364.

  The magnetic field sensor 353 detects a metal present in the waste stone on the belt conveyor 354 by using strong magnetism, and is provided so as to detect not only iron but also non-ferrous metal. In this embodiment, most of the iron pieces in the waste stone have been removed in advance by the magnetic separator 203, and the magnetic field sensor 353 mainly detects non-ferrous metals.

  The metal sorting unit 350 configured as described above operates the air nozzle 356 at a predetermined timing when the metal sensor (mainly non-ferrous metal) is detected by the magnetic field sensor 353, so that the metal pressure is reduced by the wind pressure. Blow off the hopper to the second hopper 365. On the other hand, a lump other than metals falls into the first hopper 364. Thereby, metals can be separated from the waste stone. As shown in FIG. 1, the waste stone dropped on the first hopper 364 is sent again to the raw material tank 202 and re-entered into the vertical mill 100, while the metals blown off on the second hopper 365 are stored in the container. 318 is removed.

[Mill vibration detection]
As shown in FIG. 1, in the present embodiment, the vertical mill 100 is provided with a vibration detection unit 15 that measures the vibration. The vibration detection unit 15 is not particularly limited as long as it can detect vibration. For example, the vibration detection unit 15 may detect acceleration or may detect displacement. The vibration detection unit 15 may be either a contact type or a non-contact type, and the arrangement position thereof is not limited to a specific location. As an example, the vibration detection unit 15 may be attached to the side surface of the mill casing (main body unit 141) approximately 1 meter above the table liner of the vertical mill 100.

  The direction of vibration detected by the vibration detection unit 15 may be both the horizontal direction and the vertical direction, or only one of them.

As schematically shown in FIG. 1, in this example, the vibration detection unit 15 is connected to the control unit 30. The control unit 30 is connected to a drive source of the switching unit 332 (an example), and performs the following process (an example) based on the detection result of the vibration detection unit 15:
(I) When the detected vibration of the vertical mill 100 is equal to or greater than a certain threshold value, the switching unit 332 is controlled so that the waste stone is supplied to the metal sorting unit 350.
(Ii) On the other hand, when the vibration is below a certain threshold, the switching means 332 is controlled so that the waste stone is supplied to the belt conveyor 370.

[Raw material and waste flow]
The operation of the cement manufacturing apparatus 1 of the present embodiment configured as described above will be described below.

  First, the raw raw cement material and solid waste are supplied to the belt conveyor 208 of the supply unit 200. The raw material or the like is conveyed by a belt conveyor 208 and supplied into the raw material tank 202. In the middle of being conveyed by the belt conveyor 208, the magnetic separator 203 sorts and removes the metal inner iron pieces and the like mixed in the raw raw stone.

  Next, raw raw stones and the like from the raw material tank 202 are conveyed to the vertical mill 100 by the belt feeder 207. The conveyed raw stone or the like is supplied to the raw material supply path 122 (see FIG. 2) of the vertical mill 100, and passes through the raw material supply path 122 (specifically, through the triple damper 128). Sent in.

  As shown in FIG. 2, the raw material raw material or the like sent into the main body 141 is supplied onto the crushing table 121B and finely crushed by the crushing roller 121A.

  In the vertical mill 100 of the present embodiment, when the metal foreign matter contained in the supplied raw raw stone or the like is relatively large (or a large amount), vibration generated when pulverizing also becomes large. Therefore, in the present embodiment, the vibration detection unit 15 measures the vibration of the vertical mill 100 and estimates the property of the metal foreign matter contained in the raw raw stone or the like in the mill from the magnitude of the vibration. The switching operation of the switching unit 332 based on the detection result of the vibration detection unit 15 will be described later.

  Referring again to FIG. 2, during the operation of the pulverizing table 121B and the pulverizing roller 121A, hot air having a kiln exhaust gas temperature of 300 ° C. (one example) is introduced from the gas inlet 124, and the hot air rises from the periphery of the pulverizing table 121B. A gas stream 129 is sent upward. By this ascending gas flow 129, fine powders (applicable waste) such as crushed raw stones are carried upward, classified by the classifier 123, and riding on the ascending gas flow 129 and discharged from the pulverized product outlet 125 to the outside. Is done. Note that the metals classified by the classifier 123 and discharged to the outside do not have a quality problem as cement products.

  The fine powder discharged from the outlet 125 is then collected by a cyclone 409 and sent to the cement kiln as shown in FIG. The gas from which most of the fine powder has been separated by the cyclone 409 passes through the exhaust fan 410 and is almost completely removed by the electric dust collector 411 and discharged from the chimney 412 to the atmosphere. The dust collected by the electric dust collector 411 is conveyed to a cement kiln and fired to become a cement clinker (cement intermediate product). Note that the cyclone 409 may be omitted.

  Returning to the description of the vertical mill 100 (see FIG. 2), most of the relatively large coarse particles (stone waste, separate waste) containing unmilled metals that could not get on the rising gas stream 129 are largely discharged. It falls from the stone opening 126. The fallen stones are transported by the stone belt conveyor 305 as shown in FIG. The waste stones transported by the conveyor 305 are then transported upward by the waste stone bucket elevator 306 and supplied to the switching means 332.

[Control based on mill vibration]
In the present embodiment, the vibration of the vertical mill 100 in operation is measured by the vibration detector 15 (step S1 in the flowchart of FIG. 4). The vibration detection unit 15 detects the vibration while the crushing roller 121A of the vertical mill 100 is crushing raw material or the like. The detection may be performed constantly during the pulverization of the raw material or the like, but is not limited to this, and may be performed intermittently.

  Then, the control unit 30 determines whether or not the detected vibration value f is greater than or equal to a threshold value α (step S2). It is made to supply to the metal sort | selection part 350 via the conveyor 354 (sorting system) (step S3: Supply by a sorting system).

  In the metal sorting unit 350 (see FIG. 3), first, the waste stone from the elevator 306 is received by the belt conveyor 354 (sorting system), and the belt conveyor 354 conveys the waste stone toward the hoppers 364 and 365. Metals detected by the magnetic field sensor 353 are blown off by the injection of the air nozzle 356 and jump into the second hopper 365. Exhaust stones (powder and lump) other than metals fall into the first hopper 364 from the end of the belt conveyor. The metals that have entered the second hopper 365 are removed into the container 318 as shown in FIG. On the other hand, the waste stone that has entered the first hopper 364 is put into the raw material tank 202 again.

  When the detected vibration value f is less than a certain threshold value α in step S2 of FIG. 4, the control unit 30 supplies the waste stone from the switching means 332 to the belt conveyor 370 (non-sorted system) ( Step S4: supplied by an unselected system). The waste stone supplied to the belt conveyor 370 is sent to the downstream as it is and supplied to the raw material tank 202 as described above.

  The waste stone supplied to the raw material tank 202 is sent again into the vertical mill 100 via the raw material belt feeder 207, and then the above series of operations is repeated.

[Control based on mill vibration (considering start-up time)]
In addition, the cement manufacturing apparatus 1 may operate according to the flowchart as shown in FIG. 5 in addition to the flowchart as shown in FIG. The flowchart in FIG. 5 is basically the same as that in FIG. 4, but a determination step (step S2 ′) for determining whether or not the predetermined time t has elapsed is added after the determination step in step S2. That is, when the detected vibration value f is greater than or equal to the threshold value α (step S2), and when a predetermined time t has elapsed from that point in time (when the threshold value α is greater than or equal to the threshold value α) (step S2 ′), Are distributed to the metal sorter 350.

  As described above, one reason for delaying the sorting of the waste stones to the metal sorting unit 350 by the predetermined time t is as follows. That is, for example, when the metal sorting unit 350 is stopped and operated normally for reasons of energy saving or the like, it is necessary to activate the metal sorting unit 350 at the same time as switching to the belt conveyor 354 (sorting system) due to a large vibration. However, if there is a time lag between the activation of the metal sorting unit 350 and the start of operation, the waste is supplied to the belt conveyor 354 even though the metal sorting unit 350 is not operated, and the metal is appropriately May not be removed. On the other hand, by switching to the belt conveyor 354 after the predetermined time t has elapsed (at this time, the start of the metal sorting unit 350 is completed) as described above, the metal can be appropriately removed. It becomes possible.

  The predetermined time t (step S2 ′ in FIG. 5) is determined in consideration of, for example, the time required for transporting the waste stone from the vertical mill 100 to the metal sorting unit 350. There may be.

[effect]
The invention according to the present embodiment described above is as follows.
1. In a cement manufacturing apparatus (1) using waste as a raw material or fuel for cement,
A pulverizing unit (pulverizing roller 121A, pulverizing table 121B) for pulverizing the waste, and compatible waste having a size suitable for the cement raw material or fuel and other waste having other sizes. A vertical mill (100) having a shape selection unit (grinding table 121B) for performing selection of
A circulation unit (300) for carrying out and circulating the separate waste from the shape selection unit and re-introducing the vertical mill (100);
A metal sorting section (350) for sorting metals from the separate waste,
The circulation part (300) is connected to the discharge path (305) for carrying out the separate waste from the vertical mill (100) and the discharge path, and is vertically above the vertical mill (100). A supply path (306, 354) for supplying another waste,
The metal sorting unit (350) is provided in the supply path (354), sorts and removes the metals from another waste conveyed by the supply path,
The supply path is provided with a plurality of systems, and includes (i) a sorting system (belt conveyor 354) provided with the metal sorting unit, and (ii) a non-sorting system (belt conveyor 370) other than this sorting system. ,
further,
Switching means (332) for supplying the separate waste to one of the sorting system (belt conveyor 354) and the non-sorting system (belt conveyor 370);
A vibration detector (15) for detecting vibration of the saddle mill,
The cement manufacturing apparatus (1), wherein the switching means (332) supplies the separate waste to the sorting system (belt conveyor 354) when the detected vibration exceeds a threshold value.

  The cement manufacturing apparatus (1) configured in this way has the following advantages. That is, when the metal sorting unit (350) is not provided in the circulation unit (300), once the magnetic separator (203) leaves the metal, it cannot be sorted again, but the metal sorter as in the present embodiment. If the selection part (350) is provided, metals can be removed efficiently. In addition, by providing the metal sorting unit (350) in the circulation unit (300), it is possible to greatly reduce the metal charged again into the vertical mill (100), and the vertical mill (100) and The load applied to the circulation unit (300) can be reduced.

  A general cement manufacturing apparatus is provided with a vertical mill (100) for pulverizing raw materials such as limestone. In this embodiment, the vertical mill (100) is used to pulverize the waste, so that the metals can be selected while pulverizing the waste without providing a new device. . In the circulation part (300), since the waste has already been crushed, it is more efficient to remove the metals than when removing the metals upstream from the vertical mill (100). Can be removed. Further, in the configuration as shown in FIG. 1, the iron mass has already been primarily sorted by the magnetic separator 203, and the metal sorting unit 350 removes the metals compared to the upstream (belt conveyor 208). Since the lump is small, removal of metals can be performed satisfactorily.

  In particular, when the waste is construction generated soil, the waste also contains metal, and when the amount of the metal contained increases, the metal lump collides with the inside wall of the apparatus, especially the circulation path (300). May cause adverse effects. On the other hand, in the present embodiment, when a large amount of metal passes through the vertical mill (100), the vibration of the vertical mill (100) increases, and only when the detected vibration exceeds a threshold value, the separate waste Is supplied to the sorting system (belt conveyor 354), the burden on the sorting system apparatus (belt conveyor 354) can be reduced.

  This point will be described in more detail. If a separate belt conveyor 370 is not provided as in this embodiment, waste stones are always conveyed by the belt conveyor 354 of the metal separator 350, so that the belt conveyor 354 or the like is worn or damaged. Easy to progress.

  In particular, in the metal sorting unit 350 as shown in FIG. 3, the magnetic field sensor 353 is provided inside the belt conveyor 354, and the metal is sorted through the belt conveyor 354. The conveyor 354 will be used. Therefore, measures for wear and damage of the belt conveyor 354 are particularly important. However, according to the configuration of the present embodiment, another waste is intermittently supplied to the belt conveyor 354. Wear and damage can be reduced.

  On the other hand, depending on the nature of the waste stone (that is, when there are not so many metals including non-ferrous metals), the waste stone may be returned to the vertical mill 100 without performing the metal classification. is there.

  In the present embodiment, when the vibration amount of the vertical mill 100 is equal to or greater than a predetermined threshold, in other words, only when it is estimated that a relatively large amount of metal is included in the pulverized material. Since the waste stone is supplied to the metal separation device 350 side and the rest is transported by the belt conveyor 370, the wear and damage of the belt conveyor 354 and the like of the metal separation device 350 can be suppressed.

  Even if a metal whose amount of vibration of the vertical mill does not exceed a predetermined threshold is returned from the circulation unit 300 to the vertical mill 100 again, if the amount of the metal is that level, it is powdered. Since it can be used as a cement raw material, there is no particular problem. Moreover, the damage which such metals give to the equipment of a raw material grinding | pulverization process is slight.

  Further, when the belt conveyor 370 is provided separately from the metal sorting unit 350 as in the present embodiment, even if the metal sorting unit 350 becomes inoperable due to a failure or the like, the belt conveyor 370 Therefore, it is possible to avoid stopping the entire cement raw material grinding process.

  The metal sorting unit 350 may be configured to perform an intermittent operation or may be configured to perform a continuous operation (always operation). In the case of intermittent operation, the operation cost can be reduced.

2. The switching means (332) supplies the separate waste to the sorting system (354) after a predetermined time (t) has elapsed since the detected vibration has exceeded the threshold value.
According to such a configuration, as described above, it is possible to perform excellent metal removal considering the time until the metal sorting unit 350 is operated, for example.

  The present invention is not limited to the form shown in FIG. 1, and various modifications can be made. For example, the magnetic separator 203 of FIG. 1 may be omitted. Whether or not to provide the magnetic separator 230 may be determined in consideration of the properties of the waste to be introduced.

  In FIG. 1, one control unit 30 is schematically illustrated, but such a control unit is not necessarily provided as an independent device. You may respond | correspond by giving the function similar to the control part 30 to the control means not shown which controls operation | movement of the cement manufacturing apparatus 1. FIG.

DESCRIPTION OF SYMBOLS 1 Cement manufacturing apparatus 15 Vibration detection part 30 Control part 100 Vertical mill 120 Grinding part 121A Grinding roller 121B Grinding table 122 Raw material supply path 123 Classifier 124 Gas introduction part 125 Discharge part 126 Opening part 129 Ascending gas flow 141 Main body part 200 Supply Unit 202 material tank 203 magnetic separator 207 material belt feeder 208 belt conveyor 300 circulating unit 305 waste stone belt conveyor 306 waste stone bucket elevator 332 switching means 350 metal sorting unit 353 magnetic field sensor 354 belt conveyor 356 air nozzle 364 first hopper 365 first 2 hoppers 370 belt conveyor 400 discharge unit 409 cyclone 410 exhaust fan 411 electrostatic precipitator 412 chimney

Claims (4)

In cement production equipment that uses waste as cement raw material or fuel,
A pulverizing unit for pulverizing the waste, and a shape selecting unit for selecting the pulverized waste from suitable waste of a size suitable for cement raw material or fuel and other waste of other sizes. Vertical mill,
The separate waste is circulated by unloading from the shape sorting unit, and recirculating to the vertical mill;
A metal sorting section for sorting metals from the separate waste,
The circulation unit includes a discharge path for carrying out the separate waste from the vertical mill, and a supply path connected to the discharge path and supplying the separate waste vertically above the vertical mill. ,
The metal sorting unit is provided in the supply path, sorts and removes the metals from another waste conveyed by the supply path,
The supply path is provided with a plurality of systems, and includes (i) a selection system provided with the metal selection unit, and (ii) a non-selection system other than the selection system,
further,
A vibration detector for detecting vibration of the vertical mill;
Switching means for supplying the separate waste to the selected system and supplying the separate waste to the selected system when the detected vibration exceeds a threshold value. A cement manufacturing apparatus comprising: In the cement manufacturing apparatus according to claim 1,
The switching means supplies the separate waste to the sorting system after a predetermined time has elapsed since the detected vibration becomes equal to or greater than a threshold value. A crushing unit that crushes waste, and a shape selection unit that sorts the crushed waste into compatible waste of a size suitable for the cement raw material or fuel and other waste of other sizes A mold mill, a circulation unit that carries out and circulates the separate waste from the shape sorting unit, and re-enters the vertical mill, and a metal sorting unit that sorts metals from the separate waste. In a cement manufacturing method for manufacturing cement using waste as a cement raw material or fuel by using a cement manufacturing apparatus,
The cement manufacturing apparatus includes:
The circulation unit includes a discharge path for carrying out the separate waste from the vertical mill, and a supply path connected to the discharge path and supplying the separate waste vertically above the vertical mill. ,
The metal sorting unit is provided in the supply path, sorts and removes the metals from another waste conveyed by the supply path,
The supply path is provided with a plurality of systems, and includes (i) a selection system provided with the metal selection unit, and (ii) a non-selection system other than the selection system,
Furthermore, a switching means for supplying the separate waste to one of the sorting system and the non-sorting system, and a vibration detection unit for detecting the vibration of the vertical mill,
Measuring vibration of the vertical mill;
Determining whether the measured vibration is greater than or equal to a threshold;
A step of supplying the separate waste to the sorting system when a threshold value or more is reached. In the cement manufacturing method according to claim 3,
Determining whether a predetermined time has elapsed since the measured vibration is equal to or greater than a threshold value,
The cement manufacturing method, wherein the step of supplying the separate waste to the sorting system is performed when a predetermined time has elapsed.

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