JP2006142136A - Foreign matter removal method and apparatus in slag - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To recover a slag and a foreign matter in the state that a handling property is enhanced. <P>SOLUTION: An indirect heating type drying device 24, a sieve 33, a magnetic sorting machine 37, a sieving device 27 and a dry type specific gravity sorting machine 25 are provided on a downstream side of a receiving hopper 23 for receiving a water-granulated slag 22 recovered by a fusion furnace in the order. After the water-granulated slag 22 in the receiving hopper 23 is subjected to drying treatment by the indirect heating type drying device 24, large metals and the foreign matters 34 are separated by the sieve 33. After a magnetic substance 38 is removed by the magnetic sorting machine 37, an undersize substance 22b of the sieve 33 is applied to the sieving device 27 and a slag particle having a large particle diameter having fear of generating sorting failure is previously separated as an oversize substance 22d by the dry type specific gravity sorting machine 25 at the downstream side and is recovered to a product slag recovery part 40. The undersize substance 22e of the sieving device 27 is applied to the dry type specific gravity sorting machine 25 to separate by specific gravity the foreign matter 26 having smaller specific gravity than that of the slag particle 22f. The slag particle 22f and the foreign matter 26 are recovered to the product slag recovery part 40 and a foreign matter recovery part 47 respectively. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a foreign matter removing method and apparatus for removing foreign matter such as unburned matter and unmelted dust mixed in slag obtained by melting waste, ash, and the like.

  At present, incineration is frequently performed as a waste treatment method, and as one of the treatment methods, a thermal decomposition gasification melting method of waste is known. This is because waste is charged into a pyrolysis furnace and indirectly heated in a low-oxygen atmosphere so that it is once thermally decomposed into a pyrolysis gas and a pyrolysis residue and then recovered. Both pyrolysis residues are supplied to a melting furnace, for example, a surface melting furnace, and burned at a high temperature, thereby melting incombustibles and ash to form slag. By making slag in this way, it is possible to achieve a significant volume reduction and stabilization (detoxification) of the final disposal object to be landfilled. It becomes possible to recycle slag as construction materials such as roadbed materials.

  In addition, in the conventional method of supplying waste to an incinerator and directly combusting it, which is generally known as a method for incineration of waste, the volume of the final disposal is reduced or the final disposal is harmless. In order to promote recycling and resource recycling, ash such as in-furnace ash and fly ash generated by burning waste in the incinerator is supplied to the ash melting furnace and melted to form slag. It is becoming

  In a melting furnace used in the above pyrolysis gasification melting method of waste or a melting furnace for treating ash generated in the direct combustion method of waste, as shown in FIG. The molten slag 2 generated by melting is dropped into the cooling water tank 3 provided below from the outlet 1 a of the melting furnace 1, whereby the molten slag 2 is cooled with water to form a granulated slag 4. Many are collected.

  By the way, in the melting furnace 1, when the object to be melted such as the pyrolysis residue or ash of the waste is changed or the amount or property thereof is changed, the char in the pyrolysis residue obtained from the waste pyrolysis furnace, Combustibles left unincinerated in the waste incinerator are discharged from the outlet 1a in an unburned state, or ashes such as ash generated by combustion are left in an unmelted state. It may be discharged from the shed 1a. In this way, combustibles discharged in an unburned state (hereinafter referred to as unburned matter) and unmelted ash (hereinafter referred to as unmelted dust) are discharged from the outlet 1a of the melting furnace 1. Then, when it is put into the cooling water tank 3, the unburned matter and unmelted dust adhere to the granulated slag 4 recovered from the cooling water tank 3, and the unburned slag 4 There is a possibility that unmelted dust may be mixed. In this case, in the unburned matter and unmelted dust, the contained heavy metals are not fixed, and heavy metals may be eluted. Therefore, the recovered granulated slag 4 conforms to the soil environmental standards. Incompatibility or when unburned components are mixed in, bubbles are generated in the granulated slag 4 and become unsuitable as construction materials such as roadbed materials, making it difficult to reuse them as resources.

  Therefore, it is necessary to suppress the amount of unburned matter and unmelted dust mixed in the granulated slag 4 to be recovered to a required standard or less. As one of the techniques for suppressing the amount of unburned matter and unmelted dust mixed in the granulated slag 4 as described above, the rate of melting slag can be set by controlling operation such as combustion improvement in the melting furnace 1. It is done to improve.

  However, even if the operating conditions of the melting furnace are adjusted to the optimum conditions as described above, the optimum operating conditions of the furnace can be changed if the amount and properties of the object to be melted supplied to the melting furnace fluctuate. In order to achieve optimum operating conditions, it is necessary to adjust each time according to the amount and properties of the melted object, but it is difficult to adjust the operating conditions in all operating conditions. As a result, it is difficult to eliminate the possibility of unburned matter and unmelted dust being discharged from the melting furnace 1 and prevent the unburned matter and unmelted dust from being mixed into the recovered granulated slag 4. is there.

  Therefore, as shown in FIG. 4, the granulated slag 4 recovered from the cooling water tank 3 is transported, assuming that unburned matter and unmelted dust adhering to the granulated slag 4 are washed and removed. A slag cleaning hopper 6 is provided on the downstream side of the transport device 5 such as a conveyor, and the granulated slag 4 is transported to the slag cleaning hopper 6 by the transport device 5 and temporarily stored, and stored in the slag cleaning hopper 6. The sprayed cleaning water 8 is sprayed from the cleaning nozzle 7 provided in the upper part of the hopper to the water granulated slag 4 so that unmelted dust and the like adhering to the water granulated slag 4 is cleaned and removed. (See, for example, Patent Document 1).

  In addition, as shown in FIG. 5, the water granulated slag 4 is washed in the same manner as described above. The cooling water tank 3 attached to the melting furnace 1 is provided with a conveying device 9 such as a conveyor, and the molten water slag 3 is provided in the cooling water tank 3. In the configuration in which the granulated slag 4 formed by dropping 2 is collected by the transport device 9 and taken out from the outlet 10, a cleaning spray 11 is provided at the outlet 10, and the outlet By spraying the washing water 12 from the washing spray 11 on the granulated slag 4 taken out from 10, the unburned matter and unmelted dust adhering to the granulated slag 4 are washed and removed. The thing is also proposed (for example, refer patent document 2).

  As a device for removing the metal mixed in the waste molten slag, when the waste molten slag obtained by melting the waste in the melting furnace is used as an aggregate for civil engineering construction or as a ceramic material, As shown in FIG. 6, a slag crusher 14, a sieve 15 that performs classification based on a required particle size, a specific gravity separator 16, and a water-slag separator 17 that performs solid-liquid separation are provided in order, What has been proposed has been proposed.

  More specifically, the slag crusher 14 stores the slag 13 as a raw material together with a plurality of movable bodies and water as a buffer fluid inside the rotating body, and is mutually associated with the rotation of the body. The glassy slag particles are crushed between the movable bodies approaching and separating from each other, and the metal particles mixed in the raw material slag have a rolling action so that the slag particles have a small diameter. On the other hand, the metal particles having excellent spreadability such as aluminum can be made into a flake by increasing the diameter.

  The specific gravity separator 16 is a glass having a small specific gravity in a state where a water flow having a required flow velocity is formed from one end side to the other end side in a rotating drum having a spiral groove formed on the inner peripheral surface. When crushed slag of high quality and crushed slag (metal particles) of a metal component having a higher specific gravity are introduced in a state in which the particle size is made uniform to some extent by the upstream sieve 15, these crushed slags have a difference in specific gravity between them. Accordingly, the crushed slag of the metal component settles early, and the crushed slag of the vitreous material is separated into layers so as to be positioned above the slag of the metal component. It is conveyed against the water flow by the spiral groove formed in the glass, while the glassy crushed slag that is less affected by the inner surface of the rotating drum and is easily affected by the water flow is carried on the water flow to make it vitreous. Crushing slag And crushing slag metal components are also available separation.

  Therefore, when the raw material slag 13 is supplied in the apparatus shown in FIG. 6, first, the vitreous slag particles in the raw material slag 13 are crushed and reduced in diameter by the slag crusher 14. The metal particles having excellent spreadability such as aluminum are rolled to increase the diameter. Next, by classifying with the sieve 15, the metal particles 18 a such as aluminum having a large diameter are separated and removed from the crushed slag crushed by the slag crusher 14 and reduced in diameter. . Next, among the crushed slag collected from the sieve 15 by the specific gravity separator 16, the crushed slag (metal particles such as iron, copper, SUS, etc.) 18b of the metal component is separated and removed from the vitreous crushed slag. Is done. Thereafter, the water-slag separator 17 separates and removes the water 19 from the glassy crushed slag collected from the specific gravity separator 16, thereby collecting the glassy crushed slag as product sand 20. (See, for example, Patent Document 3).

  In addition, the code | symbol 21 in FIG. 6 is the water treatment equipment for processing the water 19 isolate | separated from the product sand 20 with the said water-slag separator 17, and the treated water processed with this water treatment equipment 21 is It is made to return to the slag crusher 14 and circulate.

JP-A-9-243032 JP 2002-122319 A Japanese Patent Laid-Open No. 2003-211141

  However, as shown in FIG. 4 and FIG. 5 above, if a method in which the granulated slag 4 is washed using the washing water 8 or 12 is used, the unburned component mixed in the granulated slag 4 is used. It is possible to remove the unmelted dust and unmelted dust. In this case, however, an enormous amount of washing water is required. There is a possibility that the problem of increased costs arises.

  Further, when the granulated slag 4 is washed with the washing water 8 and 12, unburned matter and unmelted dust that are removed and transferred to the washing water 8 and 12 side are a large amount in the waste water treatment facility. Since it will be collected as a cake containing moisture, handling will be difficult due to an increase in weight more than necessary, and the unburned matter and unmelted dust collected as the cake will again be subjected to combustion treatment and melting treatment. When trying to do so, the contained moisture becomes a factor that lowers the temperature in the furnace, so that there arises a problem that unnecessary auxiliary fuel becomes necessary.

  Furthermore, since the granulated slag itself is recovered in a state where moisture is contained, it is necessary to reduce the moisture contained in the granulated slag after the recovery in order to improve handling. There is also the problem of being.

  By the way, unburned matter and unmelted dust are lighter in specific gravity than slag once melted and vitrified. In view of this point, in order to remove the unburned matter and unmelted dust mixed in the granulated slag, the specific gravity separation device 16 described in FIG. It is conceivable to separate minute and unmelted dust based on the specific gravity difference. In this case, the specific gravity separation device 16 shown in FIG. 6 separates particles having specific gravity differences into layers in the vertical direction because particles having different specific gravity differ in the ease of settling based on the specific gravity differences. For this reason, particles with a large specific gravity that sink to the lower layer are less affected by the water flow, whereas particles with a lower specific gravity distributed in the upper layer are greatly affected by the water flow and are carried on the water flow. Since each particle is subjected to specific gravity separation based on the principle that it is easy to be carried out, even if the above-mentioned granulated slag is used with the specific gravity separation device 16, unburned or unmelted dust having a lower specific gravity. Can be separated, the recovered granulated slag is in a state containing moisture, and unburned matter and unmelted dust separated by specific gravity from the granulated slag are also in a state containing moisture. Therefore, similarly to what was described in FIG. 4 and FIG. 5 above, problems such as recovered granulated slag, unburned matter, and unmelted dust handling properties occur. Furthermore, when unburned matter or unmelted dust absorbs moisture, the specific gravity becomes heavy and sinks with the slag.

  Therefore, the present invention can remove foreign matters such as unburned matter and unmelted dust mixed in the slag, and can recover the slag with a low moisture content, improving handling and making it easy to reuse. Furthermore, a foreign matter removing method and apparatus for removing foreign matter in slag that can collect unburned matter and unmelted dust and other foreign matter separated and removed from the slag in a dry state with good handling properties is provided. It is something to try.

  In order to solve the above-mentioned problem, the present invention, corresponding to the invention according to claim 1, after drying the granulated slag obtained by water-cooling the molten slag discharged from the melting furnace, the dried water Corresponding to the invention according to claim 3, wherein the crushed slag is subjected to a specific gravity sorting process by a dry method, and the foreign matter removal method in the slag for separating and removing foreign matters such as unburned matter and unmelted dust having a specific gravity smaller than the slag, and In the downstream of the receiving hopper for receiving granulated slag obtained by cooling the molten slag discharged from the melting furnace, a drying device and a dry specific gravity sorter are provided in order, and the dry granulated slag is sorted by dry specific gravity. An apparatus for removing foreign matter in slag having a configuration in which the slag particles and foreign matter are separated by a machine.

  Also, a method and apparatus for performing the drying process by the drying apparatus by an indirect heating method.

  Furthermore, in each said structure, it is set as the structure which provided the sieving apparatus between the drying apparatus and the dry-type specific gravity sorter, and led the thing with the small particle diameter of the dried granulated slag to a dry-type specific gravity sorter. .

  Furthermore, in each said structure, it is set as the structure which provided the magnetic separator between the drying apparatus and the dry-type specific gravity sorter.

  In each of the above-described configurations, a dust collector for collecting dust-like foreign matter from the drying device and the dry specific gravity sorter is provided.

According to the present invention, the following excellent effects are exhibited.
(1) Granulated slag obtained by cooling the molten slag discharged from the melting furnace is dried with a drying device, and then the dried granulated slag is subjected to specific gravity sorting with a dry specific gravity sorter. Because it is a foreign matter removal method and device in slag that separates and removes foreign matter such as unburned matter and unmelted dust with a smaller specific gravity, the difference in specific gravity between foreign matter such as unburned matter and unmelted dust mixed in the slag is reduced. Therefore, the product slag from which such foreign matters are removed can be recovered. And since what is collect | recovered as said product slag is in a state with little moisture content, the handleability of the collect | recovered product slag can be improved and it can be made into the state which is easy to reuse.
(2) In addition, since foreign matters such as unburned matter and unmelted dust separated from the slag can be recovered in a dry state, handling properties can be improved and the processing can be easily performed. Therefore, even when the foreign matter is again subjected to combustion treatment or melting treatment, useless auxiliary fuel is not required.
(3) Furthermore, since the particles recovered as product slag can be easily purified as slag, the fluctuation of the granulated slag recovered from the melting furnace due to fluctuations in the operating condition of the melting furnace. Even if the slag property deteriorates, it can be recovered by applying the foreign matter removing method and apparatus in the slag of the present invention.
(4) Furthermore, since there is no need for washing water as conventionally required to remove foreign matters mixed in the granulated slag, it is possible to eliminate the need for providing a large-scale wastewater treatment facility. The equipment can be installed compactly in a small space.
(5) Even if unburned matter is mixed in the granulated slag, which is the subject of the drying treatment, by performing the drying treatment of the granulated slag with an indirect heating type drying device. The risk of burning the unburned component can be prevented beforehand. Furthermore, foreign matters such as unburned matter and unmelted dust mixed in the slag can be prevented from being scattered or dusted.
(6) A sieving device is provided between the drying device and the dry specific gravity sorter so that the dry granulated slag having a small particle size is guided to the dry specific gravity sorter. Since the particle sizes of the particles supplied to the specific gravity sorter can be made uniform to some extent, the dry specific gravity sorter can prevent the occurrence of poor sorting of slag and foreign matters. Moreover, since the particles to be subjected to the sieving treatment are previously dried in the upstream indirect heating type drying apparatus, the particle size can be selected without being affected by the adhering water, and the particle size can be reduced. Accordingly, the purity of each component separated can be improved. Further, it is possible to avoid the possibility that mechanical troubles such as clogging of the sieves occur in the sieving device itself.
(7) By adopting a configuration in which a magnetic separator is provided between the drying device and the dry specific gravity sorter, foreign matters such as unburned matter and unmelted dust from slag previously dried in the drying device. Without mixing, magnetic substances such as metal particles having a specific gravity larger than that of slag particles can be easily separated and removed.
(8) By providing a dust collector for collecting dust-like foreign matter from the drying device and the dry specific gravity sorter, dust-like foreign matter can also be collected in a dry state, and It is possible to prevent the possibility of dusty foreign matter being discharged to the outside.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1 to FIG. 3 show an embodiment of the method and apparatus for removing foreign matter in slag of the present invention. As a basic configuration, similar to conventional granulated slag 4, pyrolysis gasification and melting of wastes. Water that is produced by water-cooling molten slag discharged from a melting furnace in a processing facility, or a melting furnace such as a melting furnace used for melting treatment of in-furnace ash, fly ash, etc. generated by direct combustion of waste A receiving hopper 23 for receiving and temporarily storing the crushed slag 22 is provided, and an indirect heating type drying device 24 and a dry specific gravity sorter 25 are sequentially provided on the downstream side of the receiving hopper 23, and the receiving hopper After the granulated slag 22 supplied from 23 is dried by the indirect heating type drying device 24, the granulated slag (dried slag) 22a in a dry state is supplied to the dry specific gravity sorter 25, Crushed slag 2 And foreign matter 26 such as unburned matter and unmelted dust mixed in the granulated slag 22 are selected based on the specific gravity difference between the two in a dry state. Can be separated and removed.

  Further, in the dry specific gravity sorter 25, the light granulated slag 22 having a large particle size should sort out and discharge foreign matter 26 such as unburned matter or unmelted dust which originally has a smaller specific gravity than the granulated slag 22. When there is a concern that a sorting failure may occur due to rolling to the side (lightweight object side) or the like, the indirect heating type drying device 24 is interposed between the indirect heating type drying device 24 and the dry specific gravity sorter 25. After drying, vibration for separating and recovering particles having a particle size larger than the required particle size, which is likely to cause sorting defects, from the dry slag 22a supplied to the dry specific gravity sorter 25 in advance. A sieving device 27 such as a sieve, a cylindrical bar screen, or a trommel is provided.

  More specifically, the receiving hopper 23 has a fixed amount cutting device (not shown) at the lower end, and the inlet 28 of the indirect heating type drying device 24 is provided on the outlet side of the fixed amount cutting device. By connecting, the granulated slag 22 in the receiving hopper 23 can be quantitatively supplied to the indirect heating type drying device 24 by a quantitative cutting device.

  For example, as shown in FIGS. 2 (a) and 2 (b), the indirect heating type drying device 24 has a trough shape having an input port 28 above one end in the longitudinal direction and a discharge port 29 at the lower end on the other end side. The transport path 30 is inclined at a required angle so that the discharge port 29 side is lower than the input port 28 side, and a vibration device (not shown) is attached to the transport path 30. A heat medium passage 31 for circulating the heat medium is embedded in the bottom surface, or the heat medium passage 31 is attached to the lower surface side of the transport path 30. As a result, the conveying path 30 is vibrated by the vibration device, and the receiving hopper 23 is fixedly cut in a state where, for example, low-pressure steam 32 of about 170 ° C. is circulated through the heat medium passage 31 as the heat medium. By introducing the granulated slag 22 cut out by the dispensing device into one end in the longitudinal direction of the conveyance path 30 through the inlet 28, the granulated slag 22 that contains about 20% moisture is obtained. While being conveyed to the discharge port 29 on the conveying path 30 that vibrates, it is indirectly heated through the bottom surface of the conveying path 30 by the low-pressure steam 32 that circulates the heating medium path 31 until the water content becomes about 10% or less. It is made to dry and can collect | recover from the discharge port 29 as the dry slag 22a. Note that when the granulated slag 22 is dried, even if unburned matter is mixed as foreign matter in the granulated slag 22 introduced from the receiving hopper 23, the drying process is indirectly performed as described above. Since the heating method is employed, it is possible to prevent the possibility that the unburned portion will burn. Further, it is possible to prevent the possibility that foreign matter 26 such as unburned matter and unmelted dust mixed in the granulated slag 22 is scattered or dusted. When the temperature of the dry slag 22a taken out after the drying process as described above is high and there is a concern about the ignition of the unburned portion mixed as a foreign matter, the outlet 29 of the indirect heating type drying device 24 A cooling device may be provided although not shown immediately after. This cooling device may be either a dry direct cooling method or an indirect cooling method, or any type of cooling device may be employed.

  In the present embodiment, as shown in FIG. 1, the particles contained in the dried slag 22a after the drying treatment are disposed at the end on the discharge port 29 side of the indirect heating type drying device 24 at a predetermined particle size, for example, The sieve 33 for separating particles having a diameter of 30 mm or more and less than 30 mm is integrally provided. This is because the granulated slag 22 usually has a particle size of less than 30 mm, so that particles having a particle size of 30 mm or more are separated as metals and other foreign matters 34 mixed in the granulated slag 22 and sieved. This is because it can be taken out from the upper product outlet 33a.

  A buffer 35, a quantitative cutting device 36, and a magnetic separator 37 are connected in order to the under sieve outlet 33b of the sieve 33, and the under sieve 22b recovered as particles having a particle diameter of less than 30 mm by the sieve 33 is obtained. Then, after being received in the buffer 35 and temporarily stored, it is supplied quantitatively to the magnetic separator 37 by the quantitative cutting device 36, the magnetic material 38 is separated by the magnetic separator 37, and taken out from the magnetic material outlet 37 a of the magnetic separator 37. So that it can be recovered.

  The non-magnetic material outlet 37b of the magnetic separator 37 has a slag cutting device 39 and a dry slag 22a that is supplied to the dry specific gravity separator 25 after being dried by the indirect heating type drying device 24 as described above. Thus, the magnetic separator 37 is connected in order with a sieving device 27 for separating and collecting particles having a particle size larger than the required particle size for which poor sorting is a concern, for example, particles having a particle size of 10 mm or more. The slag particles 22c discharged more as non-magnetic materials can be supplied to the sieving device 27 by the slag cutting device 39.

  The sieve top outlet 27a of the sieving device 27 is connected to the product slag collection part 40 so that the sieve top 22d separated as particles having a particle size of 10 mm or more can be collected as product slag. On the other hand, the sieving device outlet 27b of the sieving device 27 is connected to the input port 41 of the dry specific gravity sorter 25, and is recovered in a state where the particle size is less than 10 mm by the sieving device 27. The under-sieving material 22e can be supplied to the dry specific gravity sorter 25. In addition, since the slag particles 22c to be subjected to the sieving process in the sieving device 27 are in a dry state in advance, even if foreign matter such as unburned matter or unmelted dust is added to the supplied slag particles 22c. Even if 26 adheres, the foreign matter 26 can be easily detached from the slag particles 22c to be sieved. For this reason, it is possible to prevent the foreign matter 26 from being collected in the product slag collection unit 40 by being accompanied by the sieving material 22d having a particle diameter of 10 mm or more.

  For example, as shown in FIG. 3, the dry specific gravity sorter 25 has a trough shape having an inlet 41 at one end in the longitudinal direction and an outlet 42 at the other end, and a bottom surface serving as a conveying surface. As a plate-like material having a woven wire or a punched hole, or a cloth structure, a porous deck 43 that is capable of ejecting air 46 upward from the conveying surface is provided on the outlet 42 side rather than the inlet 41 side. A side slope 44 inclined at a required angle in the longitudinal direction so as to be lower and an end slope 45 inclined at a required angle in the width direction so that one end in the width direction of the discharge port 42 is lower than the other end in the width direction are formed. Arrange so that. Further, the porous deck 43 is provided with a vibration device (not shown) for vibrating in the width direction indicated by an arrow x in the drawing. As a result, the porous deck 43 is vibrated and air 46 is blown out from the conveying surface of the porous deck 43 to form an upward flow at a required speed by the air 46 above the conveying surface. When the sieving material 22e recovered from the sieving device 27 is introduced from the charging port 41 of the porous deck 43, each particle contained in the sieving material 22e that has been introduced is in accordance with the specific gravity of the air 46. Layered in the upward flow, particles with high specific gravity will be layered at the bottom and particles with low specific gravity will be layered at the top. For this reason, the slag particles 22f having a large specific gravity contained in the under sieve 22e are positioned in the lower layer in the upward flow of the air 46, so that the porous deck which is the transport surface 43 is brought into contact with the bottom surface of 43, and is strongly affected by the vibration in the width direction of the porous deck 43, so that the end slope is conveyed while being transported on the porous deck 43 from the inlet 41 side to the outlet 42 side. The transport surface of the porous deck 43 inclined in the width direction by 45 is moved so as to rise to the high place side, and discharged from a heavy side outlet 42a formed on the upper side of the discharge port 42. . On the other hand, the foreign matter 26 having a light specific gravity such as unburned matter or unmelted dust mixed in the under sieve 22e of the sieving device 27 is put on the upward flow in the upward flow of the air 46. Thus, the slag particles 22f having a large specific gravity are separated from the slag particles 22f and positioned in the upper layer. Accordingly, since the degree of contact with the conveying surface of the porous deck 43 is low and the influence of vibration in the width direction of the porous deck 43 is weak, the foreign matter 26 having a low specific gravity such as unburned matter or unmelted dust is It is conveyed according to the inclination of 43 and discharged from the light side outlet 42b formed on the lower side of the outlet 42 inclined in the width direction by the end slope 45.

  Therefore, the heavy side outlet 42a in the dry specific gravity sorter 25 is connected to the product slag collecting section 40 to remove the slag particles 22f from which the foreign matter 26 such as unburned matter and unmelted dust having a low specific gravity is separated and removed. To be collected as product slag. On the other hand, the light side outlet 42b is connected to the foreign matter collecting part 47 so as to collect the foreign matter 26 such as unburned matter and unmelted dust separated and separated by specific gravity from the slag particles 22f. In FIG. 3, the description of the ceiling portion that covers the top of the porous deck 43 is omitted.

  Further, in the dry specific gravity sorter 25, when separating the slag particles 22f from the foreign matter 26, the particle size is small and the weight is light among the foreign matters 26 such as unburned matter and unmelted dust that are mixed. There is a possibility that the dust-like thing will be accompanied by the upward flow of air 46 ejected from the bottom surface of the porous deck 43. For this purpose, a dust collector 49 such as a bag filter is connected to the air outlet 48 of the dry specific gravity sorter 25, and the dry specific gravity sorter 25 is used for specific gravity sorting of the slag particles 22f and the foreign matter 26. The dust-like foreign matter 26a accompanying the air 46 after that is collected by the dust collecting device 49 so as not to be discharged to the outside. The dust-like foreign matter 26a collected by the dust collector 49 is collected by the foreign matter collecting unit 47 in the same manner as the foreign matter 26 separated from the slag particles 22f by the dry specific gravity sorter 25. That's fine.

  Moreover, in the indirect heating type drying device 24, since water vapor is generated as the granulated slag 22 is dried, it is necessary to discharge the water vapor to the outside. Among the foreign matter 26 such as unburned matter and unmelted dust, the dust-like foreign matter 26a having a low specific gravity may be discharged along with the flow of water vapor. Therefore, a heater 52 and a dust collector 51 such as a bag filter are connected in order to the water vapor outlet 50 in the indirect heating type drying device 24 so that a gas such as water vapor discharged from the water vapor outlet 50 The heater 52 is heated in advance to a required temperature so that condensation does not occur inside the dust collector 51 on the downstream side, and is then passed through the dust collector 51 so that the gas discharged from the water vapor outlet 50 Even if the dusty foreign matter 26a is accompanied, the dusty foreign matter 26a can be recovered. The dust-like foreign matter 26a collected by the dust collecting device 51 is collected by the foreign matter collecting unit 47 in the same manner as the foreign matter 26a collected from the dust collecting device 49 attached to the dry specific gravity sorter 25. do it.

  When the foreign matter mixed in the granulated slag 22 is removed by using the foreign matter removing device in the slag of the present invention, the granulated slag 22 stored in the receiving hopper 23 is first used. It supplies to the indirect heating type drying apparatus 24 with a fixed quantity cutting device, and it dries. Since this drying is performed by indirect heating, there is no possibility that the unburned matter will burn even if the granulated slag 22 contains unburned matter as foreign matter 26.

  Next, the dried slag 22a subjected to the drying process is supplied to the sieve 33, and the metals and foreign matter 34 are separated and removed as the sieve top 33a having a particle diameter of 30 mm or more. Next, after the magnetic material 38 is removed by the magnetic separator 37 after being recovered as the under sieve 22b from the sieve 33, the magnetic material 38 is supplied to the sieving device 27 for selection in the dry specific gravity separator 25 as a subsequent process. Particles having a particle size of 10 mm or more that are likely to be poorly sorted in the process are collected in advance in the product slag collection unit 40 as the sieve top 22d.

  Thereafter, the sieving material 22e of the sieving device 27 is supplied to the dry specific gravity sorter 25, and the slag particles 22f and the foreign matter 26 such as unburned matter and unmelted dust mixed therein are compared with each other in specific gravity difference. The slag particles 22f are collected in the product slag collection unit 40, and the foreign material 26 is collected in the foreign material collection unit 47.

  After being used for the specific gravity sorting of the slag particles 22f and the foreign matter 26 in the specific gravity sorting process in the dry specific gravity sorter 25 in the dust-like foreign material 26a accompanying the flow of water vapor in the drying process in the indirect heating type drying device 24. The dust-like foreign matter 26 a accompanying the air 46 is collected by the corresponding dust collectors 49 and 51 and collected together with the foreign matter 26 to the foreign matter collecting unit 47.

  As described above, according to the foreign matter removal method and apparatus in the slag of the present invention, the mixed unburned matter and unburned matter are obtained from the water-cooled slag 22 obtained by water-cooling the molten slag obtained by melting waste and ash in the melting furnace. Foreign matter 26, 26a such as molten dust can be easily separated and removed, and the slag particles 22f collected from the sieve device 27d of the sieving device 27 and the dry specific gravity sorter 25 are collected as product slag. Can do. And what is collect | recovered as the said product slag, ie, the slag particle | grains 22f collect | recovered from the sieve top material 22d of the said sieving apparatus 27, and the dry-type specific gravity sorter 25, becomes a dry state with little moisture content. Therefore, handling property can be improved and it can collect | recover in the state which is easy to reuse.

  In addition, since foreign matter 26 and 26a such as unburned matter and unmelted dust separated from the product slag can be recovered in a dry state, handling property can be improved and the processing can be easily performed. Even when the foreign substances 26 and 26a are subjected to the combustion process or the melting process again, useless auxiliary fuel is not required.

  Furthermore, since it is possible to easily purify the particles recovered as product slag as slag, the slag properties of the granulated slag recovered from the melting furnace deteriorated due to fluctuations in the operating condition of the melting furnace. However, it is possible to recover by applying the method and apparatus of the present invention.

  Furthermore, according to the present invention, it is not necessary to provide slag washing water as conventionally required, so that it is not necessary to provide a large-scale wastewater treatment facility, etc. Therefore, the facility can be made compact in a small space. It becomes possible to install.

  Since both the sieve 33 and the sieving device 27 are provided on the downstream side of the indirect heating type drying device 24, the particle size selection can be performed without being affected by the water adhering to the granulated slag 22. In addition, the purity of each component separated according to the particle size can be improved, and the possibility of mechanical troubles such as clogging of the meshes can be avoided.

  Similarly, since the magnetic separator 37 is also provided on the downstream side of the indirect heating type drying device 37, the magnetic material 38 can be easily separated without mixing foreign matter 26 such as unburned matter or unmelted dust. Can be removed.

  In addition, this invention is not limited only to the said embodiment, The thing as described below is also included. For example, the indirect heating type drying device 24 of the present invention is arranged in a slanting manner in the longitudinal direction, and a low pressure as a heat medium is provided in the heat medium passage 31 provided on the bottom surface of the conveyance path 30 that can be vibrated by a vibration device. Although the steam 32 was shown to circulate, if the amount of water contained can be reduced to about 10% or less by indirectly heating the supplied granulated slag 22 to the required temperature, the heating medium passage 31 can be used. A heat medium other than the low-pressure steam 32 may be circulated as a heat medium to be circulated, or an electric heater may be used as the heat source. Further, a shape other than that shown in FIG. 2, such as a two-stage drying device in the upstream and downstream directions, may be employed. Further, although the indirect heating type drying device 24 is shown as having the sieve 33 integrally provided at the end of the discharge port 29, the sieve 33 may be a separate body. Furthermore, when granulated slag that does not contain unburned components, such as slag discharged from an ash melting furnace, is used as a treatment target, a direct heating type drying device is used instead of the indirect heating type drying device 24. You may make it perform a drying process. The dry specific gravity sorter 25 is exemplified by a vibration type, but the specific gravity difference between the particles of the granulated slag 22 and the foreign matter 26 such as unburned matter and unmelted dust mixed in the granulated slag 22 is obtained. As long as it can be sorted based on the above, any type or shape such as a wind sorting type may be adopted. In the case where the particle size distribution range of the granulated slag 22 to be subjected to the removal process of the mixed dust falls within the allowable range in which the specific gravity can be sorted without causing the sorting failure in the dry specific gravity sorter 25, the sieving device 27 May be omitted. Although the dust collectors 49 and 51 are individually connected to the downstream side of the air outlet 48 of the dry specific gravity sorter 25 and the water vapor outlet 50 of the indirect heating type dryer 24, one common dust collector is shown. You may make it connect to. Needless to say, the present invention can be applied to the treatment of slag discharged from any type of melting furnace for melting waste and ash, and various modifications can be made without departing from the scope of the present invention.

It is the schematic which shows one Embodiment of the foreign material removal method and apparatus in the slag of this invention. An example of the indirect heating type drying apparatus shown in FIG. 1 is shown, (A) is a schematic side view, (B) is an AA direction arrow view of (A). It is a schematic perspective view which shows an example of the dry-type specific gravity sorter shown in FIG. It is a schematic diagram which shows an example of the apparatus conventionally proposed in order to remove foreign materials, such as the unburned content and unmelted dust which are mixed in the granulated slag. It is a schematic diagram which shows the other example of the apparatus conventionally proposed in order to remove foreign materials, such as the unburned content and unmelted dust which are mixed in the granulated slag. It is a schematic diagram which shows the apparatus conventionally proposed in order to isolate | separate and remove the metal mixed in waste molten slag by specific gravity.

Explanation of symbols

22 Granulated slag 22a Dry slag 22b Under sieve 22c Slag particles 22d Over sieve 22e Under sieve 22f Slag particles 23 Receiving hopper 24 Indirect heating type drying equipment (drying equipment)
25 Dry specific gravity sorter 26, 26a Foreign matter 27 Sieving device 37 Magnetic separator 49 Dust collector 51 Dust collector

Claims (7)

  After the granulated slag formed by water-cooling the molten slag discharged from the melting furnace is dried, the dried granulated slag is subjected to a specific gravity selection process by a dry method, and unburned matter and unmelted dust having a specific gravity smaller than that of the slag. A method for removing foreign matter in a slag, wherein the foreign matter is separated and removed.   The method for removing foreign matter in slag according to claim 1, wherein the drying process is performed by an indirect heating method.   In the downstream of the receiving hopper for receiving granulated slag obtained by cooling the molten slag discharged from the melting furnace, a drying device and a dry specific gravity sorter are provided in order, and the dry granulated slag is sorted by dry specific gravity. An apparatus for removing foreign matter in slag, characterized by having a configuration in which the slag particles and foreign matter are separated by a machine.   The apparatus for removing foreign matter in slag according to claim 3, wherein the drying apparatus is an indirect heating type drying apparatus.   The slag in the slag according to claim 3 or 4, wherein a sieving device is provided between the drying device and the dry specific gravity sorter so that the dried granulated slag having a small particle size is led to the dry specific gravity sorter. Foreign matter removal device.   The apparatus for removing foreign matter in slag according to claim 3, 4 or 5, wherein a magnetic separator is provided between the drying device and the dry specific gravity sorter.   The apparatus for removing foreign matter in slag according to claim 3, 4, 5, or 6, further comprising a dust collecting device for collecting dust-like foreign matter from the drying device and the dry specific gravity sorter.

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