JP3699418B2 - Method and system for recycling waste incineration ash - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method and system for recycling incinerated ash obtained by incinerating at least one of general waste and industrial waste as a cement raw material.
[0002]
[Background Art and Problems to be Solved by the Invention]
Since the amount of general waste and industrial waste is enormous, in recent years, they have been incinerated at ordinary incineration facilities such as the stoker method and fluidized bed method to reduce the volume, and then landfilled at the final disposal site. However, with this method, the amount of incinerated ash is still quite large, so it is necessary to continue to create a final disposal site, but it is difficult to obtain the consent of the residents to create a new final disposal site. There is a problem.
[0003]
Incineration ash produced by incineration of general waste and industrial waste at ordinary incineration facilities may still contain hazardous substances such as heavy metals and dioxins. The incineration ash is washed and the leachate from it is treated to make the incineration ash and leachate harmless. However, unless the incineration ash is detoxified, the leachate treatment facility must be operated. In addition, since it is difficult to predict the time of detoxification by washing landfill incineration ash due to rain or the like, there is a problem that the operating cost of the water treatment facility and the maintenance cost of the final disposal site increase.
[0004]
For this reason, attempts have been made to utilize incinerated ash obtained by incineration of general waste and industrial waste by using it as resources, and as a form of its utilization, it is used as clay as a raw material for cement.
[0005]
However, when used as a raw material for cement as described above, conventionally, incineration ash obtained by incineration of those wastes is stored in a storage facility without being treated at all, and then processed by a cement company and used for cement. As it is, incineration ash as it is generally has a high salt concentration and corrodes the reinforcing bars, so it cannot be used as ordinary cement for reinforced concrete, and is therefore considered as a raw material for eco-cement used in the field of unreinforced concrete. There is a problem that the application is limited.
[0006]
By the way, the inventor of the present application stores waste in a storage tank of a waste disposal site in which a side surface and a bottom surface are formed with a steel plate to be electrically corrosion-proofed and a roof is provided as disclosed in JP-A-2000-126711. And spraying water on the waste and treating the leachate from the waste to circulate by making it into the above sprayed water, and promoting the detoxification of the waste under stable conditions, As a result of research on the waste disposal site, it was discovered that the salt content of waste can be removed by spraying water.
[0007]
[Means for solving the problems and their functions and effects]
The present invention aims to provide a recycling method and system that advantageously solves the conventional problems in view of the above-mentioned knowledge, and the recycling method of waste incineration ash according to the present invention is generally In a method of recycling incinerated ash obtained by incinerating at least one of waste and industrial waste as a cement raw material, the incinerated ash is stored in a storage tank in which side and bottom surfaces are formed with a steel plate that is electrically corrosion-resistant and a roof is provided. Sprinkle water over the incineration ash to wash away the salt from the incineration ash and use the incineration ash as a raw material for ordinary cement. Then, water is circulated , the salinity of the leachate is monitored, and the incinerated ash is carried out from the reservoir when it becomes a predetermined concentration or less .
[0008]
The system for recycling waste incineration ash according to the present invention is a system that uses incineration ash incinerated from at least one of general waste and industrial waste as a raw material for cement, and forms side and bottom surfaces using steel plates that are electrically corrosion-resistant. In addition, the incineration ash is stored in a storage tank provided with a roof, and water is sprayed on the incineration ash to wash away salt from the incineration ash, so that the incineration ash is used as a raw material for ordinary cement. the leachate was Eject outside the reservoir, and ash retention facility for the unloading of the ash from the reservoir layer when the salinity of the leachate is a predetermined concentration or less, salt from the leachate And a leachate treatment facility for monitoring the salinity of the leachate while returning the water to the incineration ash storage facility as water sprayed on the incineration ash.
[0009]
According to the resource recycling method and resource recycling system of the present invention, when incineration ash obtained by incinerating at least one of general waste and industrial waste is used as a raw material for cement, water is sprayed on the incineration ash and the incineration ash is recovered. Since the incinerated ash is recycled as a raw material for ordinary cement by washing away the salt from the raw material, the raw material can be used for a wide range of applications. In addition, incineration ash is stored in a storage tank with a roof, and water is sprayed on the incineration ash, so that the incineration ash can be made harmless under stable conditions, and the time of detoxification can be easily predicted. In addition, the salt water contained in the incinerated ash contains salt, so that the electrocorrosion protection can function effectively, and the storage tank made of steel can be easily maintained for a long period of time, and therefore leachate treatment The operation cost of the facility and the maintenance cost of the incineration ash storage facility can be reduced.
[0010]
Furthermore, according to the resource recycling method and resource recycling system of the present invention, a roof is provided in the storage tank to prevent the incineration ash from being scattered, and water from which salt has been removed from the leachate from the incineration ash is sprayed and circulated on the incineration ash. Therefore, it is possible to reduce the environmental burden compared to final disposal sites that do not have a roof to make them harmless with rainwater, and storage facilities that have a roof but store it without processing incineration ash at all. it can.
[0011]
By the way, according to the experiment by the present inventor, the chloride ion concentration in the incineration ash was equal to or lower than the chloride ion concentration of the leachate from the incineration ash, so the chloride ion concentration of the leachate was monitored. If this is the case, the chloride ion concentration of the incinerated ash in the reservoir can be ascertained. Further, according to the resource recycling method and resource recovery system of the present invention, the salinity concentration of the leachate is monitored at the leachate treatment facility. Since the incineration ash is carried out from the reservoir of the incineration ash storage facility when the concentration becomes lower than the predetermined concentration, the incineration ash having a predetermined salt concentration or less can be carried out from the reservoir.
[0012]
In the resource recycling system of the present invention, the storage tank is preferably divided into three sections. When the storage tank is used repeatedly, when the incineration ash is carried into the third section, it can be desalted in the second section, and the incinerated ash after desalting can be carried out from the first section. This is because the storage tank can be used efficiently.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a perspective view showing the appearance of an embodiment of the waste incineration ash resource recycling system according to the present invention, which implements one embodiment of the waste incineration ash recycling method according to the present invention. Is an explanatory example showing the configuration of the resource recycling system of the embodiment, FIG. 3 is a perspective view showing the reservoir of the incineration ash storage facility in the resource recycling system of the embodiment, and FIG. 4 is the resource recycling of the embodiment. It is explanatory drawing which shows the process of the leachate in the leachate treatment facility in a system.
[0014]
The system for recycling waste incineration ash according to this embodiment is a system for recycling incineration ash obtained by incinerating at least one of general waste and industrial waste as raw material (clay) of ordinary cement. As shown in FIG. 2, a circulating water spray type incineration ash storage facility 1 and a leachate treatment facility 2 are provided. The incineration ash storage facility 1 stores incineration ash A incinerated with general waste. For this purpose, a storage tank 5 which is provided in a hole dug in the ground G and is watertightly formed with a steel plate 3 which is electrocorrosion-proofed by a normal method and the outside of the steel plate 3 is surrounded by a concrete layer 4, and A roof 6 that covers the entire storage tank 5, a reservoir 7 that stores the water treated by the leachate treatment facility 2 and makeup water (rain water, etc.) as circulating water, a pump 8 that pumps the water in the reservoir 7, and a pump 8 from within reservoir 7 A sprinkling pipe 9 for evenly spraying the discharged water on the incineration ash A in the storage tank 5, a water collection pipe 10 for collecting leachate from the incineration ash A in the storage tank 5 and guiding it to the outside of the storage tank 5, And an adjustment pond 11 for storing leachate from the water pipe 10. In addition, as shown in FIG. 3, the storage tank 5 is divided into three sections for repeated use as will be described later, and each section reaches the bottom surface from the carry-in / out path 5a of the incinerated ash and the carry-in / out path 5a. A ramp 5b is provided.
[0015]
In addition, the leachate treatment facility 2 here makes the leachate from the incinerated ash A in the storage tank 5 harmless and removes the salinity therefrom, as shown in FIG. Is contained in the tank 2a that adjusts the pH (pH) of the leachate, the tank 2b that coagulates and precipitates foreign matter contained in the water that has exited the tank 2a, and the water that has exited the tank 2b. A tank 2c for biological treatment of the foreign matter present, a tank 2d for filtering the water exiting the tank 2c with sand, a tank 2e for photochemically decomposing foreign matter contained in the water exiting the tank 2d, A tank 2f that adsorbs and removes foreign substances contained in water exiting the tank 2e with activated carbon, a tank 2g that adsorbs and removes foreign substances contained in water exiting the tank 2f, and a tank 2g. Desalination treatment is performed to remove chloride ions (salts) contained in the water. And it comprises a tank 2h, water exiting the last tank 2h is accumulated in the reservoir 7.
[0016]
In addition, a known thing can be used for the said tank 2a-2h, for example, the tank 2h which performs a desalination process removes a chloride ion (salt content) by an electrodialysis method, a reverse osmosis method, an ion exchange method, etc. What is necessary is just to comprise so. In the leachate treatment facility 2, the concentration of chloride ions in the leachate from the incinerated ash A in the storage tank 5 is regularly monitored, and the concentration becomes 128 ppm or less, which is the raw material use standard for ordinary cement. Then, from the experiment of the present inventor described above, the concentration of chloride ions in the incineration ash A in the storage tank 5 should be equal to or less than that, and the incineration ash A in the storage tank 5 is Since salt can be used as a raw material for ordinary cement, it is determined that the incinerated ash A can be carried out of the reservoir 5.
[0017]
In the resource recycling method of the above embodiment using such a resource recycling system, when the incinerated ash A incinerated at least one of general waste and industrial waste is recycled as a raw material (clay) of ordinary cement, the incinerated ash is stored. The incineration ash A is stored in the storage tank 5 having the roof 6 provided with the side and bottom surfaces of the steel plate 3 that is electrically corrosive-proofed in the facility 1, and water is sprayed on the incineration ash A through the sprinkler 9 The incineration ash A is rendered harmless and the salt from the incineration ash A is washed away to use the incineration ash A as a raw material for ordinary cement. The leachate from the incineration ash A is treated at the leachate treatment facility 2 and the leachate. After the salt is removed from the leachate, the water is returned to the incineration ash storage facility 1 and sprayed onto the incineration ash A through the water spray pipe 9 to circulate the water.
[0018]
FIG. 5 is an explanatory diagram showing an example of an operation cycle when incineration ash is recycled by the resource recycling system and the resource recycling method of the above embodiment. In this example, the cleaning desalting period of the incineration ash is assumed to be 5 years. Then, after the construction of facilities 1 and 2, the incineration ash was first delivered to three sections (1) to (3) over five years in each section, and the third section (3) During the first import period, the first incineration ash from the first section (1) is carried out, and then the first incineration ash from the second section (2) During the first unloading period, the incineration ash is carried into the first section (1) for the second time, and the incineration ash from the third section (3) is being unloaded for the first time. Incineration ash is carried into the second section (2) for the second time, and then the first section (1) during the second period of delivery to the third section (3). The incineration ash from ▼ Performs a carry-out times, and then sequentially perform a second time out of the ash from the second round of carry-out and a third of the compartment ▲ 3 ▼ of ash from the compartment ▲ 2 ▼ of the second.
[0019]
As a result, the first 30 years of the above period will be the incineration ash landfill service period, and the ordinary cement raw material (clay) service period will be 30 years from the 10th year to the 40th year. And since landfill is not performed for the last 10 years, it becomes a maintenance management period of the facilities 1 and 2, and 35 years from the beginning becomes an operation period of the leachate treatment facility 2.
[0020]
FIG. 6 shows the magnitude of the environmental load when the two final disposal sites are used sequentially, when the untreated storage facility is used, and when the circulating water spraying storage facility of the above embodiment is used. It is explanatory drawing which compares and shows secular change, and when using the circulating water dispersion | spreading type | mold storage facility of the said Example as it is clear from this figure, years pass in the state with the smallest environmental load. Moreover, because there is no guarantee that the waste is completely stabilized at the final disposal site during the lifetime of the facility, there is a possibility that the operation of the leachate treatment facility may be extended. The facility can adjust the stabilization time of the incineration ash to the life of the facility by adjusting the amount of sprayed water.
[0021]
Therefore, according to the resource recycling method and resource recycling system of this embodiment, when incineration ash A incinerated at least one of general waste and industrial waste is recycled as a cement raw material, water is sprayed on the incineration ash A. By washing away the salt from the incinerated ash A, the incinerated ash A is recycled as a raw material for ordinary cement, so that the raw material can be used for a wide range of applications. Moreover, since the incineration ash A is stored in the storage tank 5 provided with the roof 6 and water is sprayed on the incineration ash A, detoxification of the incineration ash A can be promoted under stable conditions. It can be easily predicted, and the water penetrated into the incineration ash A contains salt, so that the electrocorrosion can be effectively functioned and the storage tank 5 formed of the steel plate 3 can be easily maintained for a long period of time. Therefore, the operating cost of the leachate treatment facility 2 and the maintenance cost of the incineration ash storage facility 1 can be reduced.
[0022]
Furthermore, according to the resource recycling method and resource recycling system of this embodiment, the roof 6 is provided in the storage tank 5 to prevent the incineration ash A from scattering and incinerate the water from which the salt content has been removed from the leachate from the incineration ash A. Since the closed system is constructed by spraying and circulating on the ash A, as described above, it is stored as it is without treating the incineration ash at all, even if a final disposal site without a roof to make it harmless with rainwater or a roof is provided. Compared to storage facilities, the environmental load can be reduced.
[0023]
Furthermore, according to the resource recycling method and resource recycling system of this embodiment, the storage tank 5 is divided into three sections. Therefore, when the storage tank 5 is used repeatedly, the third section ▲ as described above. When incinerated ash is carried into 3 ▼, desalting can be carried out in the second section (2) and the incinerated ash after desalting can be carried out from the first section (1), and each section can be used in the same way after that. The storage tank can be used efficiently.
[0024]
Furthermore, according to the resource recycling method and resource recycling system of this embodiment, the salinity concentration of the leachate is monitored, and the incinerated ash A is carried out from the reservoir 5 when it becomes below a predetermined concentration. Therefore, the incinerated ash A having a predetermined salt concentration or less can be carried out from the reservoir 5 and a normal cement raw material of good quality can be used.
[0025]
7 to 9 are other examples of the incineration ash storage facility that can be used in the resource recovery method and resource recovery system of the present invention, and each is a cross-sectional view showing the storage tank 5 provided on the ground G. Yes, in the example shown in FIG. 7, the side surface and bottom surface of the storage tank 5 are formed watertight with the steel plate 3 that is electrically corroded by a normal method, and the outside of the side steel plate 3 is mainly surrounded by the concrete layer 4. A roof base 12 is attached to the concrete layer 4 and a roof 6 covering the entire storage tank 5 is spanned.
[0026]
In the example shown in FIG. 8, the side surface and bottom surface of the storage tank 5 are formed watertight with the steel plate 3 that is electrocorrosion-proofed by a normal method, and a retaining wall is formed on the outside of the side surface steel plate 3 by a reinforced earth method. For example, the steel plate 3 is surrounded by a tail arme wall 13 in which a large number of strips 13a are embedded, and a roof foundation 12 is provided on the top of the tail arme wall 13 to cover a roof 6 that covers the entire storage tank 5.
[0027]
In the example shown in FIG. 9, the side surface and the bottom surface of the storage tank 5 are formed in a watertight manner with the steel plate 3 that is electrically corroded by a normal method, and the outside of the side surface steel plate 3 is made of steel that is driven into the ground G or A plurality of reinforced concrete piles 14 are enclosed and supported, and a roof 6 covering the entire storage tank 5 is spanned by using these piles 14 as a roof foundation. Even in these incineration ash storage facilities, the same effect as the incineration ash storage facility 1 in the previous embodiment can be obtained.
[0028]
FIG. 10 is an explanatory diagram showing a leachate treatment procedure in another example of a leachate treatment facility that can be used in the resource recycling method and resource recovery system of the present invention. In order to detoxify the leachate from the incinerated ash A in the tank 5 and remove salt from the tank 2a, the tank 2a accepts the leachate from the adjustment pond 11 and adjusts the pH (pH) of the leachate; The microfilter 2i that removes foreign matter contained in the water that has flowed out of the tank 2a by filtration, and chloride ions (salt) contained in the water that has exited the microfilter 2i A tank 2j for removing with an RO membrane (reverse osmosis membrane) and a tank 2k for removing chloride ions (salts) still contained in the water leaving the tank 2 with a second-stage RO membrane (reverse osmosis membrane) The water that came out of the last tank 2k is the above water storage It is accumulated to 7. Even in this leachate treatment facility, the same effect as the leachate treatment facility 2 in the previous embodiment can be obtained.
[0029]
As mentioned above, although demonstrated based on the example of illustration, this invention is not limited to the above-mentioned example, For example, the number of divisions of the storage tank of an incineration ash storage facility is made into two or less or four or more as needed. In addition, the incineration ash storage facility may be configured other than the above example, and the leachate treatment facility may also be configured to remove other foreign substances or neutralize or remove toxicity. May be.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an external appearance of an embodiment of a waste incineration ash recycling system according to the present invention, in which an embodiment of the waste incineration ash recycling method of the present invention is implemented.
FIG. 2 is an explanatory example showing a configuration of a resource recycling system according to the embodiment.
FIG. 3 is a perspective view showing a storage tank of an incineration ash storage facility in the resource recycling system of the embodiment.
FIG. 4 is an explanatory diagram showing a leachate treatment procedure in a leachate treatment facility in the resource recycling system of the embodiment.
FIG. 5 is an explanatory diagram showing an example of an operation cycle in the case of incineration ash being recycled by the resource recycling system and the resource recycling method of the embodiment.
[Fig. 6] Secular change in the magnitude of the environmental load when using two final disposal sites sequentially, when using an untreated storage facility, and when using the circulating water spray storage facility of the above embodiment It is explanatory drawing which compares and shows.
FIG. 7 is a cross-sectional view showing another example of an incineration ash storage facility that can be used in the resource recycling method and resource recycling system of the present invention.
FIG. 8 is a cross-sectional view showing still another example of an incineration ash storage facility that can be used in the resource recycling method and resource recycling system of the present invention.
FIG. 9 is a cross-sectional view showing still another example of an incineration ash storage facility that can be used in the resource recycling method and resource recycling system of the present invention.
FIG. 10 is an explanatory diagram showing a leachate treatment procedure in another example of a leachate treatment facility that can be used in the resource recycling method and resource recovery system of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Incinerated ash storage facility 2 Leachate treatment facility 2a-2k Tank 3 Steel plate 4 Concrete layer 5 Reservoir 5a Carry-in / out path 5b Slope 6 Roof 7 Reservoir 8 Pump 9 Sprinkling pipe 10 Drain pipe 11 Regulating pond 12 Roof foundation 13 Tail arme wall 13a Strip 14 Pile A Incineration ash G Ground

Claims (3)

In a method of recycling incinerated ash obtained by incinerating at least one of general waste and industrial waste as a raw material for cement,
The incineration ash is usually stored by forming the side and bottom surfaces of steel plates that are electrically corroded, storing the incineration ash in a storage tank with a roof, spraying water on the incineration ash, and washing away the salt from the incineration ash. As a raw material for cement,
After removing the salt from the water leached from the incineration ash, spraying the water on the incineration ash to circulate the water ,
A method for recycling waste incineration ash, wherein the salinity of the leachate is monitored and the incineration ash is carried out from the reservoir when it becomes a predetermined concentration or less . In a system that recycles incinerated ash from incineration of at least one of general waste and industrial waste as cement raw materials,
The incineration ash is usually stored by forming the side and bottom surfaces of steel plates that are electrically corroded, storing the incineration ash in a storage tank with a roof, spraying water on the incineration ash, and washing away the salt from the incineration ash. as a raw material for cement, and eject the leachate from the ash out of the reservoir, performing unloading of the ash from the reservoir layer when the salinity of the leachate is a predetermined concentration or less incineration An ash storage facility;
After removing salinity from the leachate and returning the water to the incineration ash storage facility as water sprayed on the incineration ash, the leachate treatment facility for monitoring the salinity concentration of the leachate,
Recycling system for waste incineration ash.   The waste incineration ash recycling system according to claim 2, wherein the storage tank is divided into three sections.

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