Vibrating screen device, stoker-type incinerator, and method for recovering valuable metals from ash of a stoker-type incinerator

Abstract

To provide a vibration sieve apparatus, a stoker type incinerator and a valuable metal recovery method which can be achieved by only improvement of an existing stoker type incinerator without needing a large scale additional device, suppress a used energy increment, and can recover valuable metals.SOLUTION: A stoker type incinerator includes: a vibration sieve apparatus 1; a first main ash chute 105 which is provided adjacent to the vibration sieve apparatus 1 and drops a large particle diameter component; a second main ash chute 121 for dropping a middle particle diameter component from a second discharge port 40 of the vibration sieve apparatus 1; and a dropped dust ash transportation conveyor 120 for recovering a small particle diameter component from a first discharge port 30 of the vibration sieve apparatus 1.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a vibrating sieve device capable of recovering valuable metals from the main ash of a stoker-type incinerator, and particularly to a vibrating sieve device that can efficiently recover valuable metals with energy savings without requiring a large additional processing device, a stoker-type incinerator equipped with the vibrating sieve device, and a method for recovering valuable metals from the ash of the stoker-type incinerator.

Background Art

[0002] In waste incineration facilities, miscellaneous garbage is incinerated, but the treatment of the incineration ash generated by such incineration is a problem, and reduction and resource utilization of the incineration ash are required. Therefore, various technologies for recovering resources (for example, valuable metals) from the incineration ash and recycling them have been proposed.

[0003] For example, Patent Document 1 discloses a metal smelting raw material recovery device that recovers metal smelting raw materials from incineration ash discharged from a grate-type waste incinerator. As shown clearly in FIG. 2 of Patent Document 1, the dust ash falling from the gaps of the grate and the nozzles of the combustion air of the grate is collected by a dust ash collection device and then sent to a waste gasification melting device for dust ash supply operation, and the main ash discharged from the end of the grate is collected by a main ash collection device and then sent to a waste gasification melting device for main ash supply operation. By switching between the two, a technique for recovering valuable metals from the dust ash has been proposed. Patent Document 1 states that since the amount of valuable metals in the main ash is small and its recovery is difficult, the main ash and the dust ash are separated and recovered, and each is melted separately in a waste gasification melting device to recover valuable metals.

[0004] Patent Document 2 proposes a method for recovering precious metals from incinerated ash, comprising: a crushing step of crushing incinerated ash containing precious metal-attached particles to which precious metals that were mixed in the waste have been attached, thereby generating precious metal-concentrated particles containing the precious metal portion scraped off from the surface of the precious metal-attached particles in the incinerated ash, and other particles; a classification step of classifying the precious metal-concentrated particles and other particles obtained in the crushing step to a certain particle size; a specific gravity separation step of separating the precious metal-concentrated particles from other particles by specific gravity separation of the particles classified in the classification step; and a high magnetic force separation step of separating magnetically adhering metals contained in the heavy ash containing the precious metal-concentrated particles using a magnetic field. The classification step is performed by sieving, and the specific gravity separation step is a dry process performed by floating the incinerated ash on an air table with an upward airflow and a suction airflow, and forming a fluidized bed in which granular ash with a high specific gravity is in the lower layer and lightweight ash with a low specific gravity is in the upper layer by vibration.

[0005] Patent Document 3 proposes a valuable metal recovery system in which incinerated ash is dried, magnetic metals are removed by magnetic separation, then sieved, and non-magnetic metal particles attached to magnetic metals of a predetermined particle size or smaller are recovered by magnetic separation and eddy current separation. The ash is then crushed, dried, and separated into fine powder (mill refined powder) and coarse powder (mill discharged material) using a vertical mill, and valuable metals are concentrated and recovered in the mill discharged material.

[0006] Patent Document 4 states that the ratio of the area of ​​the combustion air outlet to the total area of ​​the grate hearth is 2%. A method and apparatus for recovering metals from waste incineration ash is disclosed, which uses a grate with a porosity of 5% or less to separate and collect the dust ash falling from the gaps in the grate and the combustion air outlet from the main ash discharged from the end of the grate, and recover valuable metals from the separated and collected dust ash. Patent Document 4 states that valuable metals are contained in greater quantities in the dust ash than in the main ash, and that if the grate porosity is less than 2%, almost all of the valuable metals are contained in the main ash. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Patent No. 6391046 [Patent Document 2] Patent No. 6465825 [Patent Document 3] Patent No. 6375205 [Patent Document 4] Patent No. 3661662 [Overview of the project] [Problems that the invention aims to solve]

[0008] In the technology described in Patent Document 1, the bottom ash separated from the dust ash is sent directly to the subsequent waste gasification and melting device and processed together with the waste. Valuable metals are abundant in the dust ash, but the total amount of dust ash in a stoker-type incinerator is small compared to the total amount of bottom ash, and therefore only a small amount of valuable metals can be recovered from the entire waste. Furthermore, because the bottom ash, which has a high moisture content, is melted together with the waste in the waste gasification and melting device, drying equipment and wastewater treatment equipment are required, resulting in a problem of low recovery rates of valuable metals despite high energy consumption.

[0009] The technologies described in Patent Documents 2 and 3 both involve the use of magnetic separation, resulting in large-scale and complicated apparatus configurations.

[0010] The technology described in Patent Document 4 uses a grate with a specific range of grate porosity to recover valuable metals from dust ash that falls through the gaps in the grate, but does not recover valuable metals from the bottom ash. If the grate porosity deviates from the specific range, valuable metals will be included in the bottom ash, making it impossible to recover valuable metals from the incinerated ash.

[0011] Therefore, the object of the present invention is to provide a vibrating sieve device, a stoker-type incineration device equipped with the vibrating sieve device, and a method for recovering valuable metals from a stoker-type incineration device, which can be constructed by simply improving an existing stoker-type incineration device without requiring large-scale additional equipment, and which can recover valuable metals while suppressing an increase in the amount of energy used. [Means for solving the problem]

[0012] The inventors of this invention diligently studied to resolve the above problems and discovered that valuable metals are contained in the ash transferred to the main ash chute. They found that by separating this ash and recovering the ash containing valuable metals, the above objective can be achieved, and valuable metals can be recovered at low cost. This led to the completion of the present invention.

[0013] The present invention provides the following embodiments. [1] A vibrating sieve device installed in a stoker-type combustion furnace in which the inside of the incinerator can be adjusted to a negative pressure, which re-draws the lighter portion of the ash into the incinerator and classifies the ash by weight, A porous diaphragm is installed facing the inside of the incinerator, It comprises a vibrating screen tank located below the porous vibrating plate, which classifies and discharges the weight of material that falls through the porous vibrating plate, The above vibrating sieve tank includes: A first discharge port located at the bottom, which can be opened and closed, for discharging small particle weight components, A second discharge port, located above the first discharge port, is openable and closable for discharging medium-particle components, The vibrating screen tank has a forced air inlet for introducing forced air, A vibration mechanism for vibrating the above-mentioned vibrating screen tank, A vibrating screen device characterized by having a feature. [2] The vibrating sieve tank has an exhaust gas inlet for introducing exhaust gas into the vibrating sieve tank. The vibrating screen device described in [1] above, characterized in that it is provided in the above. [3] A vibrating sieve device installed in a stoker-type combustion furnace in which the inside of the incinerator can be adjusted to a negative pressure, which re-draws the lighter portion of the ash into the incinerator and classifies the ash by weight, A porous diaphragm is installed facing the inside of the incinerator, It comprises a vibrating screen tank located below the porous vibrating plate, which classifies and discharges the weight of material that falls through the porous vibrating plate, In the above-described vibrating sieve tank, a first discharge port that is located at the bottom and can be opened and closed for discharging the weight component of small particle size, a second discharge port that is located above the first discharge port and can be opened and closed for discharging the medium particle size component, a pushing air inlet for introducing pushing air into the vibrating sieve tank, a vibration mechanism for vibrating the vibrating sieve tank, a vibrating sieve device characterized in that it is provided, a first main ash chute provided adjacent to the vibrating sieve device for dropping the large particle size component, a second main ash chute for dropping the medium particle size component from the second discharge port of the vibrating sieve device, a stoker-type incinerator comprising a conveying device for receiving and conveying the small particle size component from the first discharge port of the vibrating sieve device. [4] The stoker-type incinerator according to [3] above, wherein the vibrating sieve tank further has an exhaust gas inlet for introducing exhaust gas into the vibrating sieve tank. [5] The stoker-type incinerator according to [3] or [4] above, further comprising an ash extrusion device for receiving the medium particle size component from the second main ash chute. [6] A vibrating sieve device provided in a stoker-type combustion furnace whose inside of the incinerator can be adjusted to a negative pressure, for re-sucking the light component of the ash into the incinerator and classifying the weight component of the ash, a porous vibrating plate provided facing the inside of the incinerator, a vibrating sieve tank located below the porous vibrating plate for classifying and discharging the weight component that passes through the porous vibrating plate and drops, In the above-described vibrating sieve tank, a first discharge port that is located at the bottom and can be opened and closed for discharging the weight component of small particle size, a second discharge port that is located above the first discharge port and can be opened and closed for discharging the medium particle size component, a pushing air inlet for introducing pushing air into the vibrating sieve tank, a vibration mechanism for vibrating the vibrating sieve tank, A vibrating sieve device characterized by being provided with A first main ash chute provided adjacent to the vibrating sieve device for dropping large particle size components A second main ash chute for dropping medium particle size components from the second discharge port of the vibrating sieve device A conveying device for receiving and conveying small particle size components from the first discharge port of the vibrating sieve device, and a method for recovering valuable metals from the ash of a stoker-type incinerator, characterized by comprising While introducing air from the air injection inlet of the vibrating sieve tank, vibrating the vibrating sieve tank, floating lightweight components among the main ash on the porous vibrating plate and re-sucking them into the incinerator, sifting components with weight and medium to small particle sizes from the porous vibrating plate onto the vibrating sieve tank, and leaving components with weight and large particle sizes on the porous vibrating plate in a first step Minimally or stopping the introduction of air from the air injection inlet of the vibrating sieve tank, vibrating the vibrating sieve tank, moving components with weight and large particle sizes on the porous vibrating plate to the first main ash chute and dropping them, and segregating and classifying the weight components that have fallen into the vibrating sieve tank into small particle size components and medium particle size components in a second step Minimally or stopping the introduction of air from the air injection inlet of the vibrating sieve tank, vibrating the vibrating sieve tank, opening the second discharge port, and dropping components with weight and medium particle sizes onto the second main ash chute in a third step Minimally or stopping the introduction of air from the air injection inlet of the vibrating sieve tank, vibrating the vibrating sieve tank, closing the second discharge port, slightly opening the first discharge port, dropping components with weight and small particle sizes onto the conveying device, and leaving medium particle size components in the vibrating sieve tank in a fourth step Closing the first discharge port and the second discharge port and returning to the first step in a fifth step A recovery method characterized by comprising [7] The vibrating sieve tank is further provided with an exhaust gas inlet for introducing exhaust gas into the vibrating sieve tank, and the recovery method according to [6] is characterized in that, in the first to fourth steps, when air is introduced from the forced air inlet, exhaust gas is also introduced from the exhaust gas inlet. [Effects of the Invention]

[0014] The vibrating sieve device of the present invention can be implemented simply by modifying existing stoker-type incineration facilities without requiring large-scale additional equipment, and it is possible to construct a stoker-type incineration facility that can recover valuable metals while suppressing the increase in energy consumption.

[0015] Furthermore, it is possible to separate and recover the heavy, small-particle and heavy, medium-particle components containing valuable metals in the bottom ash, which were previously transported to the bottom ash chute and could not be separated and recovered, from the heavy, medium-particle components, thereby improving the recovery efficiency of valuable metals.

[0016] Furthermore, by returning the lightweight components in the bottom ash, which were conventionally transported to the bottom ash chute, back into the incinerator and burning them again, the amount of dioxins generated due to unburned or incomplete combustion can be reduced.

[0017] Furthermore, by allowing only the large particle size components from the bottom ash, separated from the small and medium particle size components, to fall into the bottom ash chute, secondary processing of the large particle size components becomes easier, the volume of the large particle size components can be reduced, and costs such as landfill disposal can also be reduced.

[0018] Therefore, the vibrating sieve apparatus and stoker-type incinerator of the present invention are useful in recovering valuable metals and suppressing the generation of dioxins in existing ash melting apparatuses and eco-cement apparatuses. [Brief explanation of the drawing]

[0019] [Figure 1] Figure 1 is a schematic diagram illustrating the entire stoker-type incinerator of the present invention. [Figure 2]Figure 2 is a schematic diagram illustrating the vibrating screen device of the present invention. [Figure 3] Figure 3(a) is a plan view of one embodiment of a porous diaphragm, and Figure 3(b) is a cross-sectional view AA of Figure 3(a). [Figure 4] Figure 4(a) is a plan view of another embodiment of the porous diaphragm, and Figure 4(b) is a cross-sectional view AA of Figure 4(a). [Figure 5] Figure 5(a) is a plan view of yet another embodiment of the porous diaphragm, and Figure 5(b) is a cross-sectional view AA of Figure 5(a). [Figure 6] Figure 6(a) is a plan view of yet another embodiment of the porous diaphragm, and Figure 6(b) is a cross-sectional view AA of Figure 6(a). [Figure 7] Figure 7 is a schematic diagram illustrating the vibrating sieve apparatus used in the first step of the method for recovering valuable metals according to the present invention. [Figure 8] Figure 8 is a schematic diagram illustrating the vibrating sieve apparatus used in the second step of the method for recovering valuable metals according to the present invention. [Figure 9] Figure 9 is a schematic diagram illustrating the vibrating sieve apparatus used in the third step of the method for recovering valuable metals according to the present invention. [Figure 10] Figure 10 is a schematic diagram illustrating the vibrating sieve apparatus used in the fourth step of the method for recovering valuable metals according to the present invention. [Figure 11] Figure 11 is a schematic diagram illustrating the vibrating sieve apparatus used in the fifth step of the method for recovering valuable metals according to the present invention. [Figure 12] Figure 12 is a schematic diagram illustrating a conventional stoker-type incinerator. [Modes for carrying out the invention]

[0020] Preferred embodiments of the present invention will be described below with reference to the drawings, but the present invention is not limited thereto.

[0021] In stoker-type incinerators, bottom ash is produced in greater quantities than fly ash. Bottom ash contains precious metals such as gold, silver, copper, and platinum, as well as valuable metals such as zinc and lead, although in trace amounts compared to fly ash. In this specification, the precious metals and valuable metals contained in bottom ash are collectively referred to as "valuable metals."

[0022] In this invention, "highly concentrated valuable metal ash" refers to base ash containing valuable metals at a relatively high concentration due to their concentration, and "lowly concentrated valuable metal ash" refers to base ash containing valuable metals at a relatively low concentration because they are not concentrated. "Highly concentrated valuable metal ash" has a concentration of valuable metals of approximately 1.5 times or more, preferably approximately 1.7 times or more, the average concentration of valuable metals in the base ash, and "lowly concentrated valuable metal ash" has a concentration of valuable metals of approximately 0.7 times or less, preferably approximately 0.6 times or less, the average concentration of valuable metals in the base ash. It is desirable that "highly concentrated valuable metal ash" has a concentration of valuable metals of approximately 2 times or more, preferably approximately 2.5 times or more, the concentration of valuable metals in "lowly concentrated valuable metal ash". For example, if the valuable metal is copper, it is preferable that the highly concentrated valuable metal ash contains 10 g / kg or more of copper.

[0023] In this invention, "large particle size component" refers to large lumps with a particle size of 30 mm or more, such as unsuitable materials like iron scrap and ceramics, and in some cases clinker and refractories. "Medium particle size component" refers to the main ash component with a particle size of 10 mm or more and less than 30 mm. "Small particle size component" refers to the main ash component with a particle size of less than 10 mm. "Weight and medium particle size component" is a "medium particle size component" that is the main ash component containing valuable metals, and is often low-concentration ash of valuable metals. "Weight and small particle size component" is a "small particle size component" that is the main ash component containing valuable metals, and is often high-concentration ash of valuable metals.

[0024] As shown in Figure 12, in a conventionally known stoker-type incinerator 201, a drying zone stoker 211, a combustion zone stoker 213, a post-combustion zone stoker 215, and a main ash chute 205 are arranged in this order at the bottom of the incinerator body 210. Below each stoker are a drying zone chute 212, a combustion zone chute 214, and a post-combustion zone chute 216. Below each of these chutes, a dust and ash conveying conveyor 220 is installed to receive dust and ash from each chute and transport it to an ash pit (not shown). Below the main ash chute 205, an ash extrusion device 225 is installed to receive main ash and form main ash lumps. Below the ash extrusion device 225, a main ash conveying conveyor 223 is installed to receive main ash lumps from the ash extrusion device 225 and transport them to an ash pit (not shown).

[0025] The vibrating sieve device of the present invention can be installed in a conventionally known stoker-type incinerator. Therefore, the present invention also provides a stoker-type incinerator equipped with the vibrating sieve device of the present invention. Figure 1 shows an embodiment of a stoker-type incinerator equipped with the vibrating sieve device of the present invention, utilizing the basic configuration of the conventional stoker-type incinerator shown in Figure 12.

[0026] In the stoker-type incinerator 101 equipped with the vibrating screen device 1 of this embodiment, a drying zone stoker 111, a combustion zone stoker 113, a post-combustion zone stoker 115, the vibrating screen device 1, and the first main ash chute 105 are arranged in this order at the bottom of the incinerator body 110. Below each stoker are a drying zone chute 112, a combustion zone chute 114, and a post-combustion zone chute 116. Below each of these chutes, a dust and ash conveying conveyor 120 is installed to receive dust and ash from each chute and transport it to a first ash pit (not shown). As shown in Figure 2, the vibrating screen device 1 is provided with a first discharge port 30 and a second discharge port 40. Below the vibrating screen device 1 is a second main ash chute 121, and the vibrating screen device 1 is positioned to drop the main ash from the second discharge port 40 into the second main ash chute 121 and the main ash from the first discharge port 30 into the dust ash conveying conveyor (conveying device) 120. Below the second main ash chute 121 is an ash extrusion device 125, which receives the main ash and forms ash lumps. Below the ash extrusion device 125 is an ash conveying conveyor 123, which is configured to receive the ash lumps from the ash extrusion device 125 and convey them to a second ash pit (not shown). In the illustrated embodiment, an ash extrusion device 125 is provided to receive heavy and medium-sized components from the second discharge port 40. However, the vibrating sieve device of the present invention re-suctions easily scattered lightweight components into the incinerator by accompanying them with the rising airflow from the forced air inlet 27. Therefore, there is no need for the wetting treatment that was conventionally required, and the ash extrusion device 125 may not be provided. The heavy and medium-sized components from the second discharge port 40 may be dropped directly from the second main ash chute 121 to the main ash conveying conveyor (conveying device) 123.

[0027] As shown in Figure 1, the vibrating sieve device 1 of this embodiment is installed in the stoker-type combustion furnace body 110, where the inside of the incinerator becomes negatively pressurized when in operation. Through the ash pulverization and sieving caused by the vibration of the vibrating sieve device, and the upward flow caused by the forced air and the suction caused by the negative pressure inside the incinerator, the main ash, which would have fallen into the main ash chute in conventional devices, can be further separated into finer particles.

[0028] Figure 2 shows an embodiment of the vibrating sieve device of the present invention. The vibrating sieve device 1 includes a porous vibrating plate 10 provided on the upper surface facing the inside of the incinerator 110, a vibrating sieve tank 20 having a first discharge port 30 at the bottom for discharging small particle size components of the main ash, a second discharge port 40 on a side surface 22 near the bottom for discharging medium particle size components of the main ash, and a forced air inlet 27 provided on a side surface 24 where the second discharge port 40 is not provided, and a vibration applying means 23 for applying vibration to the vibrating sieve tank 20.

[0029] The vibrating sieve device 1 causes large-particle and lightweight components that cannot pass through the porous vibrating plate 10 to float up with an upward flow introduced from the forced air inlet 27, and is then re-suctioned into the incinerator 110 by the negative pressure inside the incinerator. Heavy components or large-particle components that cannot pass through the porous vibrating plate 10 and cannot float up are sent to the first main ash chute 105 by the vibration of the porous vibrating plate 10 and dropped. The main ash that has passed through the porous vibrating plate 10 is classified by the vibration of the vibrating sieve tank 20, with medium-particle components segregating upwards and small-particle components segregating downwards. The small-particle components that have segregated downwards are dropped from the first discharge port 30 to the dust ash discharge conveyor 120, and the medium-particle components that have segregated upwards are dropped from the second discharge port 40 to the second main ash chute 121 for separation.

[0030] The following describes in detail each component of the vibrating screen device of the present invention.

[0031] [Porous diaphragm] The porous vibrating plate 10 is installed in the upper opening of the vibrating sieve tank 20 facing the inside of the incinerator 101, and constitutes the upper surface of the vibrating sieve tank 20. Preferably, the porous vibrating plate 10 has an inclination angle of 1 / 100 or more and 5 / 100 or less from the end on the post-combustion zone 115 side toward the end on the first main ash chute 105 side. By providing an inclination angle of 1 / 100 or more, the porous vibrating plate can function even when the processing volume increases or when main ash is not fed from the post-combustion zone at the completion of combustion in the down-combustion phase. The main ash on the moving plate 10 can be conveyed toward the first chute 105. If the inclination angle is greater than 5 / 100, the time the main ash remains on the porous vibrating plate 10 is too short, and the classification efficiency by the vibrating sieve decreases. The porous vibrating plate 10 can be, for example, a porous plate or a slit plate, and specifically, in this embodiment, the porous plate or slit plate shown in Figures 3 to 6 can be used.

[0032] The perforated plate 10a shown in Figures 3(a) and (b) is a perforated plate in which multiple openings P are arranged in an alignment. The openings P penetrate the plate with the same width, as shown in the AA cross section in Figure 3(b). The opening diameter is preferably 10 mm or more and 30 mm or less, and more preferably 10 mm or more and 15 mm or less. The perforation ratio is preferably 3% or more and 25% or less, and more preferably 3.5% or more and 10% or less.

[0033] The perforated plate 10b shown in Figures 4(a) and (b) is a slit plate, and multiple bars b with an equilateral V-shaped cross-section are arranged in parallel, as shown in the AA cross-section in Figure 4(b), and multiple slits s are arranged in parallel in the width direction of the plate, as shown in Figure 4(a). By setting the tops of the equilateral V-shaped bars b facing upward, large particle size components larger than the width of the slits remain on the sieve, while small particle size components smaller than the width of the slits are more likely to pass through the slits and fall. The slit width is preferably 10 mm or more and 30 mm or less, and more preferably 10 mm or more and 15 mm, and the slit ratio is preferably 3% or more and 25% or less, and more preferably 3.5% or more and 10% or less.

[0034] The perforated plate 10c shown in Figures 5(a) and (b) is a slit plate, in which multiple bars b with a flat cross-section are arranged in parallel, as shown in the AA cross-section in Figure 5(b), and multiple slits s are arranged in parallel in the width direction of the plate, as shown in Figure 5(a). In addition, the spacing between each slit is narrower than that of the slits in the perforated plate shown in Figure 4. The slit width is preferably 10 mm or more and 30 mm or less, more preferably 10 mm or more and 15 mm or less, and the slit ratio is preferably 3% or more and 25% or less, more preferably 3.5% or more and 10% or less.

[0035] The perforated plate 10d shown in Figures 6(a) and (b) is formed by stacking two or more perforated plates shown in Figure 5 in an alternating pattern. A space is provided between the two stacked plates b1 and b2, each having slits. The slit widths in each plate b1 and b2 are larger than those in the perforated plates shown in Figures 4 and 5. The plates b1 and b2 are stacked so that the position of the slits s is offset between them, resulting in a diagonal gap between plates b1 and b2 of 10 mm or more and 15 mm or less. The main ash component passing through the diagonal gap between plates b1 and b2 is sieved off. The perforation ratio is preferably 3% to 25%, and more preferably 3.5% to 10%.

[0036] [Vibrating sieve tank] The vibrating sieve tank 20 is a hollow, conical-shaped tank. Although not shown in the figures, it has a rectangular opening on its top surface, and the tank body can be conical or square pyramidal in shape. In this embodiment, it is square pyramidal, and the side surface 22 located on the first main ash chute 105 side has a gentler slope than the side surface 24 on the post-combustion zone stoker 115 side, but they may have the same slope. It is preferable to have a difference in the inclination angle between side surface 22 and side surface 24 because it allows for better discharge of ash particles from the second discharge port 40, which will be described later. The vibrating sieve tank 20 is provided with a first discharge port 30 located at the bottom, which can be opened and closed for discharging small particle size components, and a second discharge port 40 located above the first discharge port 30, which can be opened and closed for discharging medium particle size components.

[0037] Furthermore, the vibrating sieve tank 20 is equipped with a motor 23 for applying vibration. A forced air inlet 27 is provided on the side 24 of the vibrating sieve tank 20 for introducing forced air into the vibrating sieve tank 20. The forced air inlet 27 is connected to a forced air blower that introduces fresh air to the drying chute 112, the combustion chute 114, and the post-combustion chute 116 in conventional devices. The forced air inlet 27 is equipped with a known airflow control mechanism (not shown) and can be freely adjusted in terms of airflow and opened and closed.

[0038] In the embodiment shown in Figure 2, an exhaust gas inlet 25 for introducing exhaust gas into the vibrating sieve tank 20 is provided on the side surface 22 of the vibrating sieve tank 20, but the exhaust gas inlet 25 is not required. When a forced air inlet 27 and an exhaust gas inlet 25 are provided, it is preferable that they be located opposite each other. The exhaust gas inlet 25 is connected to an exhaust gas introduction pipe (not shown) that recirculates the exhaust gas within the incineration equipment. The exhaust gas inlet 25 is equipped with a known airflow control mechanism (not shown) and can be freely adjusted in terms of airflow and opening / closing. It is preferable to provide the exhaust gas inlet 25 and the forced air inlet 27 opposite each other on the side surface of the cone-shaped vibrating sieve tank 20, as this generates turbulence, prevents the aggregation of the main ash in the vibrating sieve tank 20, and promotes sieving. Furthermore, by providing an exhaust gas inlet 25 and introducing exhaust gas, the amount of fresh air used as forced air can be reduced, and the exhaust gas within the incineration equipment can be effectively utilized. Furthermore, since the exhaust gas from the incineration facility is at a higher temperature than fresh air, the temperature drop inside the incinerator can be reduced, and because the oxygen concentration is lower than that of fresh air, the generation of nitrogen oxides due to combustion can be reduced.

[0039] [First discharge port] The first discharge port 30 is located at the bottom of the cone-shaped vibrating sieve tank 20 and is provided with a plate-shaped lid 31 that can be opened and closed. The size of the first discharge port 30 is arbitrary depending on the size of the vibrating sieve tank 20. The lid 31 is equipped with a motor or cylinder (not shown) for opening and closing while controlling the operation. The motor or cylinder is connected to a control computer via wiring, and various types of control, such as timer control, are possible.

[0040] [Second outlet] The second discharge port 40 is located above the first discharge port 30 and is provided on the side surface 22. Preferably, the second discharge port 40 is located at a position between 1 / 4 and 1 / 3 of the height of the vibrating sieve tank 20. The second discharge port 40 is also provided with a plate-shaped lid 41 that can be opened and closed. The size of the second discharge port 40 is arbitrary depending on the size of the vibrating sieve tank 20. The lid 41 is provided with a motor or cylinder (not shown) for opening and closing while controlling the operation. The motor or cylinder is connected to a control computer via wiring, and various types of control, such as timer control, are possible.

[0041] [Methods for recovering valuable metals] A method for recovering valuable metals from incinerated ash of a stoker-type incinerator equipped with the vibrating sieve device of the present invention will be described with reference to Figures 7 to 11. The method for recovering valuable metals of the present invention can be carried out by repeating a cycle in which the operation of the sieve vibrating device goes through the first to fifth steps shown in Figures 7 to 11 and returns to the initial state shown in Figure 7 (the state in which the first step is performed). In the illustrated embodiment, exhaust gas is introduced from the exhaust gas inlet 25, but the introduction of exhaust gas from the exhaust gas inlet 25 is not required.

[0042] The first step, shown in Figure 7, involves vibrating the vibrating sieve tank 20 while introducing air from the forced air inlet 27 and exhaust gas from the exhaust gas inlet 25. This process suspends the lightweight components of the main ash on the porous vibrating plate 10, causing the heavier, medium-to-small particle size components to pass through the porous vibrating plate 10 and fall back into the vibrating sieve tank 20, while leaving the heavier, large particle size components on the porous vibrating plate 10. As a result, the lightweight components of the main ash on the porous vibrating plate 10 of the vibrating sieve tank 20 are suspended, drawn into the furnace by the negative pressure inside the furnace, re-combusted, and then collected by a dust collector (not shown). The particles are collected by the following process. The weight components of small to medium particle size pass through the porous vibrating plate 10 and fall into the vibrating sieve tank 20.

[0043] The second step, shown in Figure 8, involves vibrating the vibrating sieve tank 20 to move heavy, large-particle components on the porous vibrating plate 10 to the main ash chute 105 and cause them to fall. Simultaneously, the heavy components that have fallen into the vibrating sieve tank 20 are segregated by vibration, with small-particle components moving downwards and medium-particle components moving upwards, thereby classifying them. The introduction of air from the forced air inlet 27 and the introduction of exhaust gas from the exhaust gas inlet 25 are both stopped or kept to a minimum amount so as not to cause small-particle components to be stirred up. Specifically, the combustion status inside the furnace and the pressure below the furnace are monitored, and the airflow rate is determined by calculation control.

[0044] The third step, shown in Figure 9, involves vibrating the vibrating sieve tank 20 to open the second discharge port 40, allowing the heavier, medium-particle-sized components that segregate upward to fall into the second main ash chute 121. The second discharge port 40 is kept open until no more ash falls. The introduction of air from the forced air inlet 27 and exhaust gas from the exhaust gas inlet 25 is either stopped or kept to a minimum amount so as not to cause small-particle-sized components to be stirred up. Specifically, the combustion status inside the furnace and the pressure below the furnace are monitored, and the airflow rate is determined by computational control. In this step as well, by continuing the vibration, segregation classification will continue.

[0045] The fourth step, shown in Figure 10, involves closing the second outlet 40 and slightly opening the first outlet 30 to allow heavy, small-particle components to fall onto the ash conveying conveyor (conveying device) 120, leaving the medium-particle components behind for classification. The opening time of the first outlet 30 is preferably controlled by a timer. The introduction of air from the forced air inlet 27 and the introduction of exhaust gas from the exhaust gas inlet 25 are both stopped or reduced to a minute amount so as not to cause small-particle components to become airborne. Specifically, the combustion status inside the furnace and the pressure below the furnace are monitored, and the airflow rate is determined by calculation control.

[0046] The fifth step, shown in Figure 11, is the process of closing the first discharge port 30 and returning to a state where the first step can be performed.

[0047] According to the stoker-type incinerator equipped with the vibrating sieve device of the present invention, segregation phenomena are utilized in the vibrating sieve tank to classify the main ash, which was conventionally not separated and subjected to secondary processing, into light components, heavy and large particle components, heavy and medium particle components, and heavy and small particle components, thereby recovering the small particle heavy components containing valuable metals. Only the vibrating sieve device needs to be installed in a conventional stoker-type incinerator; no other large-scale equipment is required, and no significant energy is added. Therefore, according to the present invention, valuable metals can be recovered efficiently without incurring initial or running costs, and by using the equipment and machinery already installed in waste incineration facilities. This provides a beneficial pre-treatment process for resource recovery systems not only for some companies and local governments, but for Japan as a whole.

[0048] [Other components] In addition to the above-described components, the vibrating screen device 1 of the present invention may include any other components without departing from the spirit of the present invention. The present invention is not limited in any way to the embodiments described above, and can be modified in various ways without departing from the spirit of the invention. [Industrial applicability]

[0049] The present invention utilizes segregation phenomena (particle size difference, specific gravity difference) to recover bottom ash from existing stoker-type incineration facilities, particularly ash containing valuable metals that were previously discarded without treatment, and provide it to intermediate processing facilities and resource recovery facilities. Therefore, the volume reduction of bottom ash and resource recovery can be effectively integrated into the system flow. This allows for the efficient recovery and resource utilization of valuable metals contained in trace amounts in the bottom ash. This will enable the 2050 Car This can contribute to building a waste-recycling society that aims for zero bonnet neutrality. [Explanation of Symbols]

[0050] 1. Vibrating screen device 10 Porous diaphragm 20 Vibrating sieve tank 23 Vibration-applying means (motor) 25 Exhaust gas inlet 27 Forced air inlet 30 First discharge port 40 Second outlet 101 Stoker-type incinerator 105 First main ash shot 110 Stoker-type incinerator body 111 Arid Zone Stoker 112 Arid Shoot 113 Combustion Zone Stoker 114 Combustion Zone Shot 115 Post-combustion zone stoker 116 Post-burn zone shot 120 Conveying device (Dust and ash conveying conveyor) 121 Second main shot 123 Conveying device (main ash conveying conveyor) 125 Ash extruder

Claims

1. A vibrating sieve device installed in a stoker-type combustion furnace in which the internal pressure of the incinerator can be adjusted to a negative pressure, which re-draws the lighter portion of the ash back into the incinerator and classifies the ash by weight, A porous diaphragm is installed facing the inside of the incinerator, It comprises a vibrating screen tank located below the porous vibrating plate, which classifies and discharges the weight of material that falls through the porous vibrating plate, The above vibrating sieve tank includes: A first discharge port located at the bottom, which can be opened and closed for discharging small particle weight components, A second discharge port, located above the first discharge port, is openable and closable for discharging medium-particle components, The vibrating screen tank has a forced air inlet for introducing forced air, A vibration mechanism for vibrating the above-mentioned vibrating screen tank, A vibrating screen device characterized by having a feature.

2. The vibrating sieve apparatus according to claim 1, characterized in that the vibrating sieve tank is further provided with an exhaust gas inlet for introducing exhaust gas into the vibrating sieve tank.

3. A vibrating sieve device installed in a stoker-type combustion furnace in which the internal pressure of the incinerator can be adjusted to a negative pressure, which re-draws the lighter portion of the ash back into the incinerator and classifies the ash by weight, A porous diaphragm is installed facing the inside of the incinerator, It comprises a vibrating screen tank located below the porous vibrating plate, which classifies and discharges the weight of material that falls through the porous vibrating plate, The above vibrating sieve tank includes: A first discharge port located at the bottom, which can be opened and closed for discharging small particle weight components, A second discharge port, located above the first discharge port, is openable and closable for discharging medium-particle components, The vibrating screen tank has a forced air inlet for introducing forced air, A vibration mechanism for vibrating the above-mentioned vibrating screen tank, A vibrating screen device characterized by having a, A first main ash chute is provided adjacent to the above-mentioned vibrating sieve device for dropping large particle size components, A second main ash chute for dropping medium-sized particles from the second discharge port of the above-mentioned vibrating sieve device, A stoker-type incinerator characterized by comprising a conveying device that receives and conveys small particle size components from the first discharge port of the vibrating sieve device described above.

4. The stoker-type incinerator according to claim 3, characterized in that the vibrating sieve tank is further provided with an exhaust gas inlet for introducing exhaust gas into the vibrating sieve tank.

5. The stoker-type incinerator according to claim 3 or 4, further comprising an ash extrusion device for receiving medium-particle components from the second main ash chute.

6. A vibrating sieve device installed in a stoker-type combustion furnace in which the internal pressure of the incinerator can be adjusted to a negative pressure, which re-draws the lighter portion of the ash back into the incinerator and classifies the ash by weight, A porous diaphragm is installed facing the inside of the incinerator, It comprises a vibrating screen tank located below the porous vibrating plate, which classifies and discharges the weight of material that falls through the porous vibrating plate, The above vibrating sieve tank includes: A first discharge port located at the bottom, which can be opened and closed for discharging small particle weight components, A second discharge port, located above the first discharge port, is openable and closable for discharging medium-particle components, The vibrating screen tank has a forced air inlet for introducing forced air, A vibration mechanism for vibrating the above-mentioned vibrating screen tank, A vibrating screen device characterized by having a, A first main ash chute is provided adjacent to the above-mentioned vibrating sieve device for dropping large particle size components, A second main ash chute for dropping medium-sized particles from the second discharge port of the above-mentioned vibrating sieve device, A method for recovering valuable metals from the ash of a stoker-type incinerator, comprising a conveying device that receives and conveys small particle size components from the first discharge port of the vibrating sieve device, The first step involves introducing air from the forced air inlet of the vibrating sieve tank while vibrating the vibrating sieve tank, causing the lightweight components of the main ash on the porous vibrating plate to float and be re-drawn into the incinerator, while the heavier components with medium to small particle sizes are sieved off from the porous vibrating plate into the vibrating sieve tank, and the heavier components with large particle sizes remain on the porous vibrating plate. A second step involves introducing a small amount of air from the forced air inlet of the vibrating sieve tank or stopping it altogether, vibrating the vibrating sieve tank, moving the heavy and large-particle components on the porous vibrating plate to the first main ash chute and causing them to fall, and then segregating the heavy components that have fallen into the vibrating sieve tank into small-particle and medium-particle components for classification. A third step involves introducing a small amount of air from the forced air inlet of the vibrating sieve tank to the vibrating sieve tank, causing the vibrating sieve tank to vibrate, opening the second discharge port, and allowing the heavy and medium-particle components to fall into the second main ash chute. A fourth step involves introducing a small amount of air from the forced air inlet of the vibrating sieve tank to the vibrating sieve tank, causing the vibrating sieve tank to vibrate, closing the second discharge port, and slightly opening the first discharge port to allow components of heavy weight and small particle size to fall into the conveying device, while leaving components of medium particle size in the vibrating sieve tank. A fifth step involves closing the first and second discharge ports and returning to the first step. A recovery method characterized by comprising the following:

7. The recovery method according to claim 6, wherein the vibrating sieve tank is further provided with an exhaust gas inlet for introducing exhaust gas into the vibrating sieve tank, and in the first to fourth steps, exhaust gas is introduced from the exhaust gas inlet when air is introduced from the forced air inlet.

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