System and method for producing aggregate from incineration ash

Abstract

To provide a system and a method for producing aggregate from incineration ash that can convert low-density classified ash as a whole into aggregate having good quality.SOLUTION: The system comprises: a kneader 65 configured to knead supplied low-density classified ash with water; a granulator 66 configured to form the low-density classified ash kneaded by the kneader 65 into granules; a carbonation treatment device 67 configured to perform carbonation of the low-density classified ash by exposing the granulated low-density classified ash formed by the granulator 66 to exhaust gas containing carbon dioxide while conveying the granulated low-density classified ash; a measuring device 69 configured to periodically measure a value related to the hardness of the granulated low-density classified ash carbonated by the carbonation treatment device 67; and a controller 90. The controller 90 executes at least one of the following controls when the measured value obtained by the measuring device 69 is equal to or less than a predetermined value: the control to increase the exposure time of the low-density classified ash to the exhaust gas in the carbonation treatment device 67; the control to increase the amount of exhaust gas introduced into the carbonation treatment device 67; and the control to decrease the amount of low-density classified ash supplied to the kneader.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a system and method for converting incineration ash into aggregate. [Background technology]

[0002] Conventionally, waste such as municipal waste has been incinerated in incinerators, and the ash produced by the incineration has been disposed of in landfills at final disposal sites.

[0003] In recent years, attempts have been made to recover and recycle metals from incineration ash, or to turn the incineration ash from which metals have been removed into aggregate and effectively use it as civil engineering materials, etc. This reduces the amount of incineration ash transported to final disposal sites and also helps extend the life of final disposal sites.

[0004] Patent Document 1 describes a method in which waste incineration ash is separated into high-specific-gravity separated ash and low-specific-gravity separated ash using a specific-gravity separation device, and then the low-specific-gravity separated ash is brought into contact with purified exhaust gas discharged from an incinerator using a carbonation treatment device, thereby carbonating the low-specific-gravity separated ash. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2023-43984 Summary of the Invention [Problem to be solved by the invention]

[0006] In the carbonation treatment device disclosed in Patent Document 1, low-specific-gravity sorted ash is carbonated and formed into granules using a screw-type granulator supplied with water and exhaust gas, and the granular low-specific-gravity sorted ash is exposed to exhaust gas while being transported on a conveyor, thereby promoting carbonation. The carbonated granular low-specific-gravity sorted ash is then sorted by a gravity sorting device and converted into aggregate, which can be effectively used as civil engineering materials, etc. The configuration of Patent Document 1 leaves room for improvement in terms of converting the low-specific-gravity sorted ash into high-quality aggregate.

[0007] The present disclosure has been made to solve the above-mentioned problems, and aims to provide an aggregate production system and aggregate production method for incineration ash that can generally produce high-quality aggregate from low-specific-gravity sorted ash. [Means for solving the problem]

[0008] In order to achieve the above object, a system for producing aggregate from incineration ash according to one aspect of the present disclosure includes a system in which incineration ash from waste, which is discharged from an incinerator that incinerates waste and has particle sizes aligned within a predetermined range, is separated into high-specific-gravity separated ash, which is mainly composed of particles with a high specific gravity, and low-specific-gravity separated ash, which is mainly composed of particles with a low specific gravity, and the low-specific-gravity separated ash is supplied, and the system includes a kneader that mixes the low-specific-gravity separated ash with water, a granulator that forms the low-specific-gravity separated ash mixed in the kneader into granules, and a transport system that draws in exhaust gas containing purified carbon dioxide discharged from the incinerator and transports the granular low-specific-gravity separated ash formed in the granulator. The apparatus comprises a carbonation treatment device that carbonates the granular low-specific-gravity selected ash by exposing it to the exhaust gas while it is still in a hard state; a measuring device that periodically measures the hardness value of the granular low-specific-gravity selected ash carbonated by the carbonation treatment device; and a controller, wherein when the measurement value of the measuring device is below a predetermined value, the controller performs at least one of the following controls: increase the time for which the granular low-specific-gravity selected ash is exposed to the exhaust gas in the carbonation treatment device; increase the amount of exhaust gas drawn in by the carbonation treatment device; and decrease the amount of low-specific-gravity selected ash supplied to the kneader.

[0009] In addition, a method for producing aggregate from incineration ash according to one aspect of the present disclosure includes separating incineration ash from waste that has been discharged from an incinerator for incinerating waste and has particle sizes within a predetermined range into high-specific-gravity separated ash, which is mainly composed of particles with a high specific gravity, and low-specific-gravity separated ash, which is mainly composed of particles with a low specific gravity, and mixing the low-specific-gravity separated ash with water, forming the mixed low-specific-gravity separated ash into granules, drawing in exhaust gas containing purified carbon dioxide that has been discharged from the incinerator, and using the formed granules. The low-specific-gravity selected ash is exposed to the exhaust gas while being transported, and the granular low-specific-gravity selected ash is carbonated. The hardness value of the carbonated granular low-specific-gravity selected ash is measured periodically, and if the measured hardness value is equal to or less than a predetermined value, at least one of the following is implemented: increasing the time for which the granular low-specific-gravity selected ash is exposed to the exhaust gas during the carbonation; increasing the amount of exhaust gas drawn in during the carbonation; and decreasing the amount of the low-specific-gravity selected ash to be mixed. [Effects of the Invention]

[0010] The present disclosure has the effect of providing an incineration ash aggregate production system and aggregate production method that have the configuration described above and can convert low-specific-gravity separated ash into high-quality aggregate overall. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a diagram showing a schematic configuration of an example of an incineration ash processing system including an incineration ash aggregate production system according to this embodiment, and related facilities. [Figure 2] FIG. 2 is a schematic diagram showing an example of the gravity separation device and aggregate production system of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0012] Preferred embodiments of the present disclosure will be described below with reference to the drawings. Note that the same or corresponding elements will be designated by the same reference numerals throughout the drawings, and redundant explanations will be omitted. The drawings are schematic illustrations of the respective components for ease of understanding, and the shapes, dimensional ratios, and the like may not be accurately depicted. The present disclosure is not limited to the following embodiments.

[0013] (Embodiment) FIG. 1 is a diagram showing a schematic configuration of an example of an incineration ash processing system including an incineration ash aggregate production system according to this embodiment, and related facilities.

[0014] In Figure 1, an incineration plant BS is shown as a related facility of the incineration ash treatment system AS. The incineration plant BS is equipped with an incinerator 7 for incinerating waste, a boiler 8, a turbine 9, a generator 10, and a dust collector 11, a blower 12, and a chimney 13 as exhaust gas treatment equipment.

[0015] The incinerator 7 is a stoker-type incinerator having a main combustion chamber 7A, a re-burning chamber 7B, a hopper 71, a dust feeder 72, and multiple stokers 73. Waste fed into the hopper 71 is sent to the main combustion chamber 7A by the dust feeder 72, where it dries, ignites, and burns on the stoker 73. The main ash m remaining after combustion is discharged through a discharge chute 74. This main ash m and the falling ash n that falls from the stoker 73 are supplied to the incineration ash conveying device 1. The combustion exhaust gas from the main combustion chamber 7A is completely combusted in the re-burning chamber 7B.

[0016] The boiler 8 has a first flow path 81 disposed above the re-burning chamber 7B, a second flow path 82 communicating with the first flow path 81, and a third flow path 83 communicating with the second flow path 82 and having a superheater 84 disposed therein. The boiler 8 is configured to recover heat from the exhaust gas passing through the first to third flow paths 81 to 83 and generate steam. The generated steam is sent to a turbine 9 connected to a generator 10 and used for power generation. The exhaust gas that has passed through the boiler 8 is purified by a dust collector 11 and then released into the atmosphere from a chimney 13 via a blower 12.

[0017] In addition, in this embodiment, a portion of the exhaust gas G1 passing through the flue 14 between the dust collector 11 and the blower 12 is supplied to the aggregate system 6, and the exhaust gas G2 that has passed through the aggregate system 6 is returned to the flue 14 and released into the atmosphere from the chimney 13 via the blower 12.

[0018] The incineration ash treatment system AS includes an incineration ash transport device 1, a vibration conveyor 2, a hanging magnetic separator 3, a classifier 4, a gravity separator 5, and an aggregate system 6.

[0019] The incineration ash conveying device 1 is a dry conveyor configured so that cooling air g is supplied from below the wire mesh belt conveyor. The incineration ash conveying device 1 conveys incineration ash P, which consists of dust ash n and main ash m discharged from an incinerator 7, and supplies it to the vibrating conveyor 2.

[0020] The incineration ash P supplied to the vibrating conveyor 2 is transported by the vibrating conveyor 2 and passes under the hanging magnetic separator 3, where magnetic materials such as iron are removed, and the ash is then supplied to the classifier 4.

[0021] The classifier 4 can be configured, for example, by a vibrating screen. The incineration ash, whose particle size has been made uniform within a predetermined range by the classifier 4, is supplied to the gravity separator 5. The incineration ash whose particle size is outside the predetermined range is processed separately.

[0022] The gravity separator 5 separates the incineration ash supplied from the classifier 4 into high-specific-gravity separated ash and low-specific-gravity separated ash. The low-specific-gravity separated ash separated by the gravity separator 5 is supplied to the aggregate production system 6, while the high-specific-gravity separated ash is processed separately. Here, the high-specific-gravity separated ash is incineration ash whose main component is high-specific-gravity particles, which are particles with a large specific gravity, and the low-specific-gravity separated ash is incineration ash whose main component is low-specific-gravity particles, which are particles with a small specific gravity. The incineration ash supplied from the classifier 4 to the gravity separator 5 contains, for example, high-specific-gravity particles, which are heavy metals such as Cu and Pb, and low-specific-gravity particles such as Si, Ca, and Al.

[0023] FIG. 2 is a schematic diagram showing an example of the gravity separator 5 and aggregate production system 6 of FIG. 1. The gravity separator 5 shown in FIG. 2 has a device main body 51 that is roughly rectangular and elongated in the direction of the arrow x. The device main body 51 has an open top, and a breathable metallic vibration plate 52 is disposed in this opening. A discharge chute 54 is disposed at the top end of one longitudinal end of the device main body 51, and a discharge chute 55 is disposed at the top end of the other end. In addition, a vibration device 53 is fixed to both side surfaces of the device main body 51 in the width direction.

[0024] Device body 51 is inclined, with the four corners of its bottom surface elastically supported on base 57 by four springs 56. A blower 59 is installed inside base 57, and a flexible pipe 58 is installed between base 57 and device body 51. Air supplied from blower 59 is supplied into device body 51 through flexible pipe 58, and the airflow is adjusted inside device body 51 so that the air is blown up evenly from the entire surface of diaphragm 52.

[0025] The vibrating plate 52 is inclined so that one end 52a in the longitudinal direction is higher than the other end 52b in accordance with the inclination of the device body 51. A supply port 50 for incineration ash supplied from the classifier 4 is installed above the center of the vibrating plate 52. The vibrating plate 52 has numerous small holes large enough to allow air to pass through but prevent the incineration ash from falling. The vibrating device 53 is composed of a vibration motor or the like, and vibrates the device body 51 equipped with the vibrating plate 52 in the direction of arrow S1 at a predetermined period and amplitude.

[0026] In this gravity separator 5, the vibrating plate 52 is vibrated in the direction of arrow S1 by the vibrating device 53. The high-specific-gravity particles of the incineration ash supplied from the classifier 4 to the center of the vibrating plate 52 move toward the discharge chute 54 and are discharged from the discharge chute 54. Meanwhile, the low-specific-gravity particles are suspended by the air blowing up from below the vibrating plate 52 and are barely affected by the vibration of the vibrating plate 52. They move downwards by gravity toward the vibrating plate 52 and are discharged from the discharge chute 55. However, in practice, the high-specific-gravity particles and the low-specific-gravity particles cannot be completely separated and separated. In other words, the high-specific-gravity separated ash discharged from the discharge chute 54 is primarily composed of high-specific-gravity particles but also contains a small amount of low-specific-gravity particles. The low-specific-gravity separated ash discharged from the discharge chute 55 is primarily composed of low-specific-gravity particles but also contains a small amount of high-specific-gravity particles. The low-specific-gravity separated ash discharged from the discharge chute 55 is supplied to the aggregate-making system 6.

[0027] In Figure 2, the low-specific-gravity separated ash discharged from the specific gravity separator 5 is configured to be supplied directly to the aggregate-making system 6, but it may also be configured to be supplied to the aggregate-making system 6 via a conveying device or the like. Furthermore, the specific gravity separator 5 is not limited to the example shown in Figure 2, and may be any device that can separate the incineration ash supplied from the classifier 4 into high-specific-gravity separated ash and low-specific-gravity separated ash.

[0028] The aggregate-making system 6 shown in Figure 2 is an example of the incineration ash aggregate-making system of this embodiment. This aggregate-making system 6 includes an ash receiving device 61, a measuring and conveying device 62, a calcium source supplying device 63, a water supplying device 64, a kneading machine 65, a granulating machine 66, a carbonation treatment device 67, a detector 68, a measuring device 69, a sample taking-out device 70, a controller 90, an input device 91, and the like.

[0029] The ash receiving device 61 receives the low-specific-gravity separated ash discharged from the discharge chute 55 of the gravity separator 5 and supplies it to the weighing and conveying device 62. The ash receiving device 61 includes, for example, a cylindrical body 61a that receives the low-specific-gravity separated ash, two discharge chutes 61b and 61c installed at the bottom of the cylindrical body 61a, and a rotatable gate 61g. When the gate 61g is in the state shown by the solid line, all of the low-specific-gravity separated ash received in the cylindrical body 61a is supplied to the weighing and conveying device 62 through the discharge chute 61b. When the gate 61g is in the state shown by the two-dot chain line, a portion of the low-specific-gravity separated ash received in the cylindrical body 61a is discharged through the discharge chute 61c into the storage container 101, and the remaining portion is supplied to the weighing and conveying device 62 through the discharge chute 61b.

[0030] The detector 68 is configured using an elemental analyzer such as an energy dispersive X-ray fluorescence analyzer that employs the FP method, and is capable of instantaneously analyzing the elements contained in the target object. The detector 68 detects in real time the concentration of calcium contained in the low-specific-gravity separated ash supplied from the specific gravity separator 5 to the ash receiving device 61, and transmits this detected concentration to the controller 90.

[0031] The calcium source supplying device 63 can supply a calcium source to, for example, the ash receiving device 61. This allows the calcium source to be added to the low-specific-gravity separated ash supplied from the specific gravity separator 5. Here, the calcium source supplied by the calcium source supplying device 63 can be slaked lime made of calcium hydroxide, quick lime made of calcium oxide, or both slaked lime and quick lime.

[0032] The weighing and conveying device 62 is configured, for example, by a conveyor scale that continuously weighs the weight of the low-specific-gravity sorted ash on the conveyor while transporting the low-specific-gravity sorted ash by the conveyor. The low-specific-gravity sorted ash transported by the weighing and conveying device 62 is supplied to the kneader 65.

[0033] The kneader 65 kneads the low-specific-gravity separated ash supplied from the weighing and conveying device 62 with water supplied from the water supply device 64, and supplies the resulting mixture to the granulator 66. The water supply device 64 is configured to be able to adjust the amount of water supplied to the kneader 65.

[0034] The granulator 66 forms the kneaded low-specific-gravity separated ash supplied from the kneader 65 into granules, and supplies them to a carbonation treatment device 67 .

[0035] The carbonation treatment device 67 includes a case body 671 equipped with a discharge chute 674, a conveyor 672 disposed within the case body 671, and a blower 673 for supplying exhaust gas G1 containing carbon dioxide to the case body 671.

[0036] The blower 673 draws in a portion of the exhaust gas G1 passing through the flue 14 between the dust collector 11 and the blower 12 in Fig. 1 and supplies it to the case main body 671. The exhaust gas G2 that has passed through the case main body 671 is returned to the flue 14 and is released into the atmosphere from the chimney 13 via the blower 12.

[0037] Granular low-specific-gravity separated ash supplied from granulator 66 is supplied near the upstream end of conveyor 672 in case body 671 of carbonation treatment device 67. Conveyor 672 is configured, for example, as a wire mesh belt conveyor, and exhaust gas G1 is supplied from below from blower 673.

[0038] In this carbonation treatment device 67, the granular low-specific-gravity sorted ash is carbonated by being exposed to exhaust gas G1 while being transported by a conveyor 672. This results in granular low-specific-gravity sorted ash with increased hardness, i.e., aggregate-like granular low-specific-gravity sorted ash, which is then discharged from a discharge chute 674.

[0039] The discharge chute 674 has an opening midway, at which a sample extraction chute 70s is installed, along with a gate 70g that opens and closes the opening. The sample extraction chute 70s and gate 70g form the sample extraction device 70. When the gate 70g changes from a closed state indicated by a solid line to an open state indicated by a two-dot chain line, a portion of the granular low-specific-gravity separated ash passing through the discharge chute 674 passes through the sample extraction chute 70s and is supplied to the measuring device 69 as a sample. The gate 70g is controlled by the controller 90 so that it periodically changes from a normally closed state to an open state, and a sample is periodically supplied to the measuring device 69.

[0040] The measuring device 69 includes, for example, a hardness tester that applies a load to the granular low-specific-gravity sorted ash supplied as a sample to measure its hardness. The hardness tester transmits the measured hardness of the granular low-specific-gravity sorted ash to the controller 90.

[0041] The controller 90 is, for example, a computer having an arithmetic unit such as a CPU and memory units such as a ROM and RAM, and the CPU executes a predetermined program pre-stored in the memory unit to control the operation of the entire aggregate-forming system 6. That is, the controller 90 controls the gate 61g of the ash receiving device 61, the measuring and conveying device 62, the calcium source supply device 63, the water supply device 64, the kneader 65, the granulator 66, the carbonation treatment device 67, and the gate 70g of the sample taking-out device 70. The controller 90 may be configured as a single controller that performs centralized control, or may be configured as a plurality of controllers that cooperate with each other to perform decentralized control.

[0042] The input unit 91 is a device that is operated by the user to input desired information to the controller 90.

[0043] It should be noted that the functions of the controller 90 disclosed herein can be performed using circuits or processing circuits, including general-purpose processors, special-purpose processors, integrated circuits, ASICs (Application Specific Integrated Circuits), conventional circuits, or combinations thereof, configured or programmed to perform the disclosed functions. A processor is considered a processing circuit or circuit because it includes transistors and other circuitry. In this disclosure, a circuit, unit, or means is hardware that performs the recited functions or hardware that is programmed to perform the recited functions. The hardware may be hardware disclosed herein or other known hardware that is programmed or configured to perform the recited functions. Where the hardware is a processor, which is considered a type of circuit, the circuit, unit, or means is a combination of hardware and software, and the software is used to configure the hardware and / or processor.

[0044] Here, carbonation of incineration ash from waste will be explained. Waste typically contains shells and other materials containing calcium carbonate. When such waste is burned in the incinerator 7, calcium carbonate (CaCO3) is decomposed into quicklime (CaO) and carbon dioxide (CO2). The quicklime produced here is contained in the incineration ash, and is therefore contained in the low-specific-gravity separated ash supplied to the ash receiving device 61 via the classifier 4 and the specific gravity separator 5. This quicklime (CaO) reacts with water (H2O) in the kneader 65 to form slaked lime (Ca(OH)2). Then, in the carbonation treatment device 67, calcium carbonate (CaCO3) is formed when the slaked lime (Ca(OH)2) reacts with carbon dioxide (CO2) contained in the flue gas G1. In this way, when the granular low-specific-gravity separated ash is carbonated in the carbonation treatment device 67 to form calcium carbonate, other components can also be incorporated into the granular low-specific-gravity separated ash to solidify it.

[0045] Next, the operation control of the aggregate-forming system 6 will be described. In the following, the calcium source supply device 63 will be described as supplying slaked lime as a calcium source. Here, it is assumed that the aggregate-forming system 6 is operating with the two gates 61g, 70g each shown by a solid line and with no slaked lime being supplied from the calcium source supply device 63 to the ash receiving device 61. In this case, the low-specific-gravity separated ash discharged from the discharge chute 55 of the specific gravity separator 5 is received by the ash receiving device 61 and supplied in its entirety to the weighing and conveying device 62. The weighing and conveying device 62 weighs the low-specific-gravity separated ash in real time as it is being conveyed, and supplies the low-specific-gravity separated ash from the discharge end to the kneader 65.

[0046] The weighing and conveying device 62 transmits the weight of the weighed low-specific-gravity sorted ash to the controller 90, and the controller 90 controls the amount of water supplied by the water supply device 64 to the kneader 65 in accordance with the weight of the low-specific-gravity sorted ash. Here, the water supply device 64 is controlled so that the amount of water supplied is within a predetermined range of, for example, about 5 to 30% of the weight of the low-specific-gravity sorted ash supplied to the kneader 65, in order to ensure that the amount of water supplied is an amount suitable for carbonation of the low-specific-gravity sorted ash.

[0047] The low-specific-gravity sorted ash mixed with water in the kneader 65 is supplied to a granulator 66, which forms it into granules and supplies them to the upstream end of a conveyor 672 of a carbonation treatment device 67. While being transported by the conveyor 672, the granular low-specific-gravity sorted ash is exposed to flue gas G1 drawn in from the flue 14 by a blower 673 operating at a predetermined air volume. This causes carbonation, increasing the hardness and turning it into granular low-specific-gravity sorted ash that has been converted into aggregate, which is then discharged from a discharge chute 674.

[0048] During the above operation, the detector 68 detects the calcium concentration in real time contained in the low-specific-gravity separated ash supplied from the specific gravity separator 5 to the ash receiver 61 and transmits this detected concentration to the controller 90. If the detected calcium concentration is below a predetermined concentration, the controller 90 transmits a calcium source addition command to the calcium source supply device 63. Upon receiving the calcium source addition command, the calcium source supply device 63 supplies a predetermined amount of slaked lime to the ash receiver 61. This adds slaked lime to the low-specific-gravity separated ash supplied to the kneader 65 via the weighing and conveying device 62, thereby increasing the proportion of calcium contained in the granular low-specific-gravity separated ash supplied to the carbonation treatment device 67 via the kneader 65 and granulator 66. This increases the proportion of calcium carbonate produced by carbonation, allowing the granular low-specific-gravity separated ash to solidify to a hardness suitable for aggregate. On the other hand, if slaked lime is not added when the detected calcium concentration is below a predetermined concentration, the calcium content of the granular low-specific-gravity separated ash supplied to the carbonation treatment device 67 is low, resulting in a low proportion of calcium carbonate produced by carbonation, which may prevent the granular low-specific-gravity separated ash from being solidified to a hardness suitable for aggregate. Therefore, by adding slaked lime when the calcium concentration of the low-specific-gravity separated ash supplied from the specific gravity separation device 5 is below a predetermined concentration, the low proportion of calcium carbonate produced by carbonation can be prevented from being reduced, and the carbonated granular low-specific-gravity separated ash can be solidified to a hardness suitable for aggregate. In other words, the carbonated granular low-specific-gravity separated ash can be solidified to a hardness suitable for aggregate. The predetermined concentration is input into the controller 90 via the input device 91 by a user and stored in the memory of the controller 90. Note that, although the calcium source supply device 63 supplies slaked lime in the above example, similar effects can be achieved by supplying quicklime instead of slaked lime, or by supplying both slaked lime and quicklime, as described above.

[0049] During the above operation, the controller 90 periodically opens the gate 70g of the sampler 70, as indicated by the two-dot chain line, at predetermined intervals to extract a sample of carbonated granular low-specific-gravity sorted ash and supply it to the measuring device 69. The measuring device 69 measures the hardness of the sample and transmits the measured hardness to the controller 90. If the measured hardness of the sample is below a predetermined hardness, it is likely that uncarbonated calcium remains in the granular low-specific-gravity sorted ash discharged from the discharge chute 674. Therefore, the controller 90 may perform a first control operation to increase the airflow rate of the blower 673 by a predetermined amount. This increases the amount of exhaust gas G1 containing carbon dioxide drawn in, promoting carbonation of the granular low-specific-gravity sorted ash and solidifying the carbonated granular low-specific-gravity sorted ash to a hardness suitable for aggregate. In other words, the carbonated granular low-specific-gravity sorted ash can be generally converted into high-quality aggregate.

[0050] Furthermore, as a second control, the controller 90 may be configured to reduce the conveying speed of the conveyor 672 by a predetermined speed when the measured hardness of the sample is equal to or lower than a predetermined hardness. This increases the time that the granular low-specific-gravity sorted ash is exposed to exhaust gas on the conveyor 672, promoting carbonation and solidifying the carbonated granular low-specific-gravity sorted ash to a hardness suitable for aggregate. In other words, the carbonated granular low-specific-gravity sorted ash can be made into high-quality aggregate.

[0051] Furthermore, if the measured hardness of the sample is equal to or less than a predetermined hardness, the controller 90 may perform a third control by opening the gate 61g of the ash receiving device 61 by a predetermined angle, as indicated by the two-dot chain line, to discharge a portion of the low-specific-gravity separated ash received from the specific gravity separator 5 into the storage container 101. In this case, the amount of low-specific-gravity separated ash supplied from the ash receiving device 61 to the kneader 65 via the weighing and conveying device 62 can be reduced, and the amount of granular low-specific-gravity separated ash supplied to the carbonation treatment device 67 via the granulator 66 can be reduced. This increases the amount of carbon dioxide contained in the exhaust gas relative to the low-specific-gravity separated ash to be carbonated, thereby promoting carbonation. The carbonated granular low-specific-gravity separated ash can be solidified to a hardness suitable for aggregate. In other words, the carbonated granular low-specific-gravity separated ash can be converted into high-quality aggregate.

[0052] When the measured hardness of the sample is equal to or less than a predetermined hardness, the controller 90 preferably performs at least one of the first to third controls. The predetermined hardness to be compared with the measured hardness of the sample is input in advance to the controller 90 from the input device 91 by a user's operation and stored in the memory of the controller 90.

[0053] In this embodiment, the measuring device 69 may be a device for measuring the weight percentage of calcium carbonate contained in the granular low-specific-gravity separated ash supplied as a sample, instead of a hardness meter. In this case, the measuring device 69 includes, for example, a container for storing the supplied sample, a weight measuring device for measuring the weight of the sample in the container, a heating device for heating the sample in the container, and a carbon dioxide concentration meter for measuring the carbon dioxide concentration in the container before and after the heating. The measuring device 69 measures the weight of the sample stored in the container and then heats the sample. By heating, the calcium carbonate in the sample decomposes, generating carbon dioxide. The measuring device 69 then calculates the weight percentage of calcium carbonate contained in the low-specific-gravity separated ash in the sample based on the measured weight of the sample and the increase in carbon dioxide concentration before and after heating measured by the carbon dioxide concentration meter, and transmits this weight percentage to the controller 90. Note that a high weight percentage of calcium carbonate indicates a high hardness of the sample, while a low weight percentage of calcium carbonate indicates a low hardness of the sample. Therefore, the weight percentage of calcium carbonate is an example of a value related to hardness.

[0054] In this case, it is preferable that the controller 90 performs at least one of the first to third controls when the weight percentage of calcium carbonate received from the measuring device 69 is equal to or less than a predetermined percentage. In this case, the predetermined percentage is input in advance to the controller 90 from the input device 91 by a user's operation and stored in the memory of the controller 90.

[0055] In this embodiment, the measuring device 69 is configured to automatically measure the hardness of the sample or the weight percentage of calcium carbonate contained in the sample and transmit the measured value to the controller 90, but this is not limited to this. For example, the hardness of the sample or the weight percentage of calcium carbonate contained in the sample may be measured through a user's operation, and the user may input the measured value into the controller 90 by operating the input device 91.

[0056] From the above description, many improvements and other embodiments of the present disclosure will be apparent to those skilled in the art. Therefore, the above description should be construed as illustrative only and is provided for the purpose of teaching those skilled in the art the best mode for carrying out the present disclosure. Details of the structure and / or function thereof can be substantially changed without departing from the spirit of the present disclosure.

[0057] Summary of the Disclosure The incineration ash aggregate production system according to the first aspect of the present disclosure is a system in which incineration ash from waste, which is discharged from an incinerator that incinerates waste and has particle sizes aligned within a predetermined range, is separated into high-specific-gravity separated ash, which is mainly composed of particles with a high specific gravity, and low-specific-gravity separated ash, which is mainly composed of particles with a low specific gravity, and the low-specific-gravity separated ash is supplied, and the system includes a kneader that mixes the low-specific-gravity separated ash with water, a granulator that forms the low-specific-gravity separated ash mixed in the kneader into granules, and a system that draws in exhaust gas containing purified carbon dioxide discharged from the incinerator and conveys the granular low-specific-gravity separated ash formed in the granulator while conveying the exhaust gas. The apparatus comprises a carbonation treatment device that carbonates the granular low-specific-gravity selected ash by exposing it to exhaust gas, a measuring device that periodically measures the hardness value of the granular low-specific-gravity selected ash carbonated by the carbonation treatment device, and a controller, and when the measurement value of the measuring device is below a predetermined value, the controller performs at least one of the following controls: increase the time for which the granular low-specific-gravity selected ash is exposed to the exhaust gas in the carbonation treatment device; increase the amount of exhaust gas drawn in by the carbonation treatment device; and decrease the amount of low-specific-gravity selected ash supplied to the kneader.

[0058] According to this configuration, the hardness value of the carbonated granular low-specific-gravity sorted ash is periodically measured using a measuring device. If the measured value is below a predetermined value, it is believed that uncarbonated calcium remains in the granular low-specific-gravity sorted ash. Therefore, if the measured value is below a predetermined value, carbonation can be promoted by increasing the time the granular low-specific-gravity sorted ash is exposed to exhaust gas containing carbon dioxide in the carbonation treatment device. Furthermore, if the measured value is below a predetermined value, the amount of exhaust gas drawn into the carbonation treatment device can be increased to increase the amount of carbon dioxide and promote carbonation. Furthermore, if the measured value is below a predetermined value, the amount of low-specific-gravity sorted ash supplied to the kneader can be reduced to increase the amount of carbon dioxide relative to the low-specific-gravity sorted ash to be carbonated, thereby promoting carbonation. As described above, promoting carbonation allows the carbonated granular low-specific-gravity sorted ash to be solidified to a hardness suitable for aggregate. In other words, the carbonated granular low-specific-gravity sorted ash can be generally converted into high-quality aggregate.

[0059] The incineration ash aggregate production system according to the second aspect of the present disclosure may be the incineration ash aggregate production system according to the first aspect, wherein the measuring device measures the hardness of the granular low-specific-gravity separated ash carbonated in the carbonation treatment device as the value related to the hardness.

[0060] The incineration ash aggregate production system according to a third aspect of the present disclosure is the incineration ash aggregate production system according to the first aspect, wherein the measuring device measures the weight percentage of calcium carbonate contained in the granular low-specific-gravity separated ash carbonated in the carbonation treatment device as the value related to the hardness.

[0061] In addition, a method for producing aggregate from incineration ash according to one aspect of the present disclosure includes separating incineration ash from waste that has been discharged from an incinerator for incinerating waste and has particle sizes within a predetermined range into high-specific-gravity separated ash, which is mainly composed of particles with a high specific gravity, and low-specific-gravity separated ash, which is mainly composed of particles with a low specific gravity, and mixing the low-specific-gravity separated ash with water, forming the mixed low-specific-gravity separated ash into granules, drawing in exhaust gas containing purified carbon dioxide that has been discharged from the incinerator, and using the formed granules. The low-specific-gravity selected ash is exposed to the exhaust gas while being transported, and the granular low-specific-gravity selected ash is carbonated. The hardness value of the carbonated granular low-specific-gravity selected ash is measured periodically, and if the measured hardness value is equal to or less than a predetermined value, at least one of the following is implemented: increasing the time for which the granular low-specific-gravity selected ash is exposed to the exhaust gas during the carbonation; increasing the amount of exhaust gas drawn in during the carbonation; and decreasing the amount of the low-specific-gravity selected ash to be mixed.

[0062] According to this method, the hardness value of the carbonated granular low-specific-gravity sorted ash is periodically measured. If the measured value is below a predetermined value, it is believed that uncarbonated calcium remains in the granular low-specific-gravity sorted ash. Therefore, if the measured value is below a predetermined value, carbonation can be promoted by increasing the time for exposing the granular low-specific-gravity sorted ash to exhaust gas containing carbon dioxide during carbonation. Furthermore, if the measured value is below a predetermined value, the amount of exhaust gas introduced during carbonation can be increased to increase the amount of carbon dioxide and promote carbonation. Furthermore, if the measured value is below a predetermined value, the amount of low-specific-gravity sorted ash to be mixed can be reduced to increase the amount of carbon dioxide relative to the low-specific-gravity sorted ash to be carbonated, thereby promoting carbonation. As described above, promoting carbonation allows the carbonated granular low-specific-gravity sorted ash to be solidified to a hardness suitable for aggregate. In other words, the carbonated granular low-specific-gravity sorted ash can be generally converted into high-quality aggregate. [Explanation of symbols]

[0063] 6 Aggregate System 65 Mixer 66 Granulator 67 Carbonation treatment device 69 Measuring Equipment 90 Controller

Claims

1. The waste incineration ash discharged from an incinerator for incinerating waste and having particle sizes aligned within a predetermined range is sorted into high-specific-gravity sorted ash mainly composed of particles with a high specific gravity and low-specific-gravity sorted ash mainly composed of particles with a low specific gravity. The low-specific-gravity sorted ash is supplied to a kneader which kneads the low-specific-gravity sorted ash with water; a granulator that forms the low-specific-gravity separated ash mixed in the mixer into granules; a carbonation treatment device that draws in exhaust gas containing purified carbon dioxide discharged from the incinerator and exposes the granular low-specific-gravity sorted ash formed by the granulator to the exhaust gas while transporting the granular low-specific-gravity sorted ash; and a measuring device for periodically measuring the hardness value of the granular low-specific-gravity separated ash carbonated by the carbonation treatment device; a controller; The controller When the measurement value of the measuring device is equal to or less than a predetermined value, at least one of the following controls is carried out: a control to increase the time for which the granular low-specific-gravity separated ash in the carbonation treatment device is exposed to the exhaust gas; a control to increase the amount of the exhaust gas drawn into the carbonation treatment device; and a control to decrease the amount of the low-specific-gravity separated ash supplied to the kneader. Aggregation system.

2. The measuring device measures the hardness of the granular low-specific-gravity separated ash carbonated by the carbonation treatment device as the value related to the hardness. The system for converting incineration ash into aggregate according to claim 1.

3. the measuring device measures the weight percentage of calcium carbonate contained in the granular low-specific-gravity separated ash carbonated in the carbonation treatment device as the value related to the hardness; The system for converting incineration ash into aggregate according to claim 1.

4. Incineration ash of waste discharged from an incinerator for incinerating waste and having particle sizes aligned within a predetermined range is separated into high-specific gravity separated ash mainly composed of particles with a high specific gravity and low-specific gravity separated ash mainly composed of particles with a low specific gravity, and the low-specific gravity separated ash is kneaded with water, The mixed low-specific-gravity separated ash is formed into granules, exhaust gas containing purified carbon dioxide discharged from the incinerator is drawn in, and the formed granular low-specific-gravity sorted ash is exposed to the exhaust gas while being transported, thereby carbonating the granular low-specific-gravity sorted ash; periodically measuring the hardness value of the carbonated granular low specific gravity sorted ash; When the measured value relating to the hardness is equal to or less than a predetermined value, at least one of increasing the time for which the granular low-specific-gravity sorted ash is exposed to the flue gas when performing the carbonation, increasing the amount of the flue gas drawn in when performing the carbonation, and decreasing the amount of the low-specific-gravity sorted ash to be mixed is performed. A method for turning incineration ash into aggregate.

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