JP4004252B2 - Waste melting treatment method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for melting waste, and more specifically, an object to be processed in a wide area melting process or landfill for melting incineration main ash and / or incineration fly ash carried from a plurality of waste incineration facilities. Dig up the dumped waste that has been disposed of, and melt the waste to be treated in the dumped waste melting process that melts the dumped waste that has been dug up individually or in a state where the objects to be treated for both melting treatments are mixed. The present invention relates to a method for melting waste.
[0002]
[Prior art]
In general, when melting incineration main ash, which is the residue of incineration of waste that has been incinerated in a waste incinerator, and incineration fly ash collected in the flue of the waste incinerator, it is scattered during transportation. In order to prevent this, the incineration main ash and incineration fly ash are transported from each waste incinerator to a waste melting furnace in the form of wet ash with water added. The same applies to the wide-area melting process in which workpieces from a plurality of waste incineration facilities not equipped with a melting furnace are transported to a wide-area melting processing facility and melted together. By the way, the incineration main ash contains metals such as iron cans and non-combustible coarse materials. Prior to putting the wet ash into the waste melting furnace, removal of iron cans and Separation and crushing are performed as pretreatment. The removal of the iron cans is performed mainly by magnetic separation, and other noncombustible coarse materials are separated by sieving, specific gravity separation, or the like. The separated coarse product (usually over 30 mm) is subjected to a preliminary crusher, and the size is adjusted to 30 mm or less. In addition, since the said iron cans have ash adhering, it is hard to recycle as a useful metal, and it is discarded after sorting.
[0003]
On the other hand, in the case of a landfill site that has been landfilled in the past, even if this is a waste that has been properly dumped at the time of landfilling, it may no longer meet the standards at present. In addition, due to the rapid increase in waste in recent years, there is a shortage of landfill sites. Under these circumstances, dumping waste disposal that has been disposed of in landfills in the past is dug up again, melted using the waste melting furnace of these wide-area melting treatment facilities, and dumped waste melting treatment is planned to be landfilled again as reduced molten slag. Has been.
[0004]
[Problems to be solved by the invention]
In the treatment of wet ash from the above-mentioned conventional waste incineration facilities, the separated iron cans are not recovered as useful metals, but if this is recovered and used as useful metals, wet ash will adhere. It is necessary to clean iron cans, which requires equipment or a great deal of labor, labor and time. By the way, with regard to the above-mentioned dumping waste, in old landfill disposal sites, organic materials including combustible materials such as garbage, plastics and rubber are buried together with non-combustible waste including metals. When excavating and melting, it is necessary to pre-treat and separate combustible materials. In addition, iron cans also have a problem that they cannot be used as useful metals unless the iron cans to which wastes are attached are washed, as in the case of the wide-area melting treatment. Therefore, if they are to be melted together, the pretreatment process must be extremely complicated. That is, in the case of the wide-area melting treatment, the iron cans in the object to be processed and the non-combustible coarse substances are wet ash, but the iron cans in the object to be processed in the case of the dumped material melting process What adheres to the soil is part of the landfilled waste and its spoilage in addition to the soil. These may have caused rust in iron cans for many years. This means that the cleaning method is different even as far as iron cans are concerned. In the case of oversized products, combustible materials are included in the case of dumped material melting treatment, and it is necessary to separate them. Thus, if it is going to perform wide area melting processing and dumping thing melting processing in the same facility, it has the big problem that pre-processing must be a very complicated process.
[0005]
From another point of view, when excavating landfilled waste, removing iron cans from the waste, and refilling the remainder after high-temperature melting treatment, iron cans are removed by removing the iron cans. Therefore, it is possible to easily determine the usefulness of enabling reduction of the backfill amount. However, there are many iron cans in the excavated waste that have been rusted as described above, and those that have wet ash attached to them. Considering the process of washing away the waste by washing and separating only the iron cans In such a case, the deposits could not be completely removed by washing alone, making it difficult to reuse the iron cans that were taken out.
[0006]
Therefore, the waste melting method of the present invention solves the above-mentioned problems, and simply adds a simple facility, and does not greatly change the pretreatment process between the wide-area melting processing and the dumped material melting processing. The object is to provide means that can be easily implemented in the same facility and can also recover iron in a reusable form.
[0007]
[Means for Solving the Problems]
[0008]
[Characteristics of the present invention]
The waste melting method according to the present invention is an object to be processed in a wide-area melting process for melting incineration main ash and / or incineration fly ash carried from a plurality of waste incineration facilities, or both, or landfilled. The waste to be processed by digging up the dumped waste and melting the dumped waste that has been dug up, individually or in a mixed state of the products to be processed for both melting processes In the melt processing method, the object to be processed In addition It has a feature in that it includes a heat treatment step for performing a heat treatment, and each has the following features.
[0014]
The first characteristic means of the waste melting method of the present invention for the above-mentioned object is as set forth in claim 1, wherein a heat treatment step for heat-treating the object to be treated, and a treatment after the heat treatment Sort and collect metal from objects After heating A sorting and collecting step, and a melting treatment step for performing a melting treatment on the workpiece after separating the metal, and prior to the heating treatment step of the workpiece, While taking out, the one with a large particle size is crushed and processed into a workpiece having a predetermined particle size or less, and the workpiece containing iron is obtained by applying a magnetic force to the workpiece obtained by this treatment. Take out things Before heating Magnetic sorting process Before heating A heat treatment process for performing heat treatment on an object to be processed including iron taken out by magnetic separation, a rotary kiln part to which the object to be processed is sent, and a burner that sends combustion hot gas to the kiln part It is in the point comprised so that it may be performed with the rotary kiln which has.
[0015]
The second characteristic means of the waste melting method of the present invention for the above-described object is that, as described in claim 2, a vibrating force is applied to the heat-treated object discharged from the rotary kiln. After urging separation of iron and non-ferrous components, iron is separated by applying a magnetic force to the workpiece. After heating The sorting and collecting process is configured.
[0016]
[Operation and effect of characteristic means]
According to the waste melting method according to the present invention, the pretreatment for melting the object to be processed is simplified by including the heat treatment. Has an effect.
[0017]
According to the first characteristic means, the object to be processed In addition When heat treatment is performed and at least the object to be treated is dried, and the object to be treated contains a combustible material, the combustible material can be burned by further heating, and deposits can be removed from the surface of the mixed metal. It is. Accordingly, the metal in the object to be processed can be easily and easily separated, and the failure caused by the metal in the melting process can be prevented. And since the metal dries and combustible material has adhered and is burned and removed, it can be utilized as a metal resource without any particular cleaning.
As a result, the wide area melting process and the dumped substance melting process can be easily performed in the same facility without greatly changing the pretreatment process.
[0021]
And in a state where the object to be processed is set to a predetermined particle size or less by pretreatment, Before heating It is possible to create an object to be processed that contains a lot of iron by magnetic separation.
As a result, the iron can be easily taken out from the object to be processed while being easily processed with a fixed particle size.
[0022]
Also, Heating is performed while rotating the workpiece containing a lot of iron in the rotary kiln, so that the combustible material adhering to the iron is burned, the moisture is evaporated and removed, and at the same time, the heating is performed without rotation by stirring by rotation. To increase the ratio of iron after heating and promote separation of iron and residue.
As a result, iron can be easily taken out by setting the form of heat treatment.
[0023]
According to the second characteristic means, separation of iron and non-ferrous content is promoted by vibrations on the object to be processed after heat treatment, and then iron is separated by the action of magnetic force. After heating In the sorting and recovery process, only iron can be easily recovered.
As a result, it is possible to recover iron that has been dried with less adhesion of impurities, and facilitate the reuse of iron.
[0024]
DETAILED DESCRIPTION OF THE INVENTION
[First Embodiment]
An example of an embodiment of the waste melting method according to the present invention will be described below with reference to the drawings.
[0025]
Digging up the waste to be treated in the wide-area melting process that melts the incinerated main ash and / or incinerated fly ash carried from multiple waste incineration facilities, or both, or the dumped waste that has been dug up The object to be processed in the dumped object melting process for melting the object is melted individually or in a state where the objects to be processed for both melting processes are mixed. For example, as shown in FIG. 1, wastes received from a waste incineration facility, a landfill site, or both from a melting treatment facility are first subjected to size selection, and coarse ones are crushed. Then, a pretreatment condition is selected according to the properties of the received waste (in the example shown, any one of the first pretreatment condition, the second pretreatment condition, and the third pretreatment condition is selected). For example, the first pretreatment condition is a heating temperature of 200 to 400 ° C, the second pretreatment condition is a heating temperature of 550 to 700 ° C, and the third pretreatment condition is a heating temperature of 850 to 900 ° C. . The first pretreatment condition is for wet ash whose combustible material is only incombustible material, the second pretreatment condition is for wet ash containing combustible material, and the third pretreatment condition is from a disposal site. This is for dumped waste that has been dug up. Next, the object to be processed is subjected to heat treatment under the selected pretreatment conditions. The object to be treated after the heat treatment is taken out and the contained metal is sorted and recovered. Here, when there is no coarse material other than metal, metals such as iron, aluminum, and copper can be separated only by simple classification means such as a vibrating sieve, and the separated and collected metal has little deposits. It can be recovered as metal. The sieve after classification is subjected to a melting treatment as an object to be processed. If the object to be processed after the size is adjusted and the metal is removed is melted, an operation failure caused by the metal in the waste melting furnace can be prevented. The molten slag taken out from the waste melting furnace is landfilled as it is, and the molten fly ash collected by the dust collector provided in the flue of the waste melting furnace is made harmless by chelation treatment etc., and then the same as the molten slag Dispose to landfill.
[0026]
The above process is performed in a wide area melting treatment facility as shown in FIG. 3, for example. In the example shown in the figure, dumped waste excavated from a landfill site is carried by truck transportation, and wet ash from the waste incineration facility in the area is carried by container transportation. The carried waste 20 is first subjected to a visual inspection as a processing object inspection. Thereafter, the workpiece 21 is supplied to the pretreatment heating furnace 1 for the heat treatment step. As the pretreatment heating furnace 1, a rotary kiln type heating furnace is used, and combustion air is supplied into the furnace as necessary. As shown in FIG. 3, the flue 2 that guides the exhaust gas from the pretreatment heating furnace 1 has a gas cooling device 3, for example, a dust collector 4 made of a bag filter, and an exhaust gas treatment device such as an activated carbon adsorption tower. 5. Ventilation equipment 6 such as an induction fan is arranged in order, and the exhaust gas is discharged from the chimney 7 into the atmosphere. The gas cooling device 3 is for lowering the exhaust gas temperature to below the service temperature of the subsequent bag filter. The exhaust gas treatment device 5 is for detoxifying the exhaust gas when, for example, vinyl chloride or the like that generates harmful gas by heating is present in the dumped waste. In addition, when the waste 20 before thrown into the said pretreatment heating furnace 1 contains the coarse thing more than predetermined size, it throws into a crusher and the coarse thing 22 is crushed. In this case, the workpiece 21 is adjusted to a size of 300 mm or less by crushing the coarse product 22. The purpose is to increase the efficiency of the heat treatment. That is, separation or combustion of gas (steam, pyrolysis gas, or combustion gas) generated by heat treatment is facilitated.
[0027]
The heating temperature of the pretreatment heating furnace 1 is controlled by the heating furnace control mechanism 16 according to the above pretreatment conditions. The pretreatment condition is set according to the result of the above-described workpiece inspection. For example, if the waste 20 carried in is wet ash from the waste incineration facility, it is incinerated main ash and incinerated fly ash and contains almost no combustible material, so the above-mentioned first pretreatment condition is selected. To do. When the waste 20 contains mainly the wet ash and combustibles are mixed in part, the second pretreatment condition described above is selected. When the waste 20 is mainly dumped waste, the above-described third pretreatment condition is selected. This heating furnace control mechanism 16 should be capable of controlling not only the heating temperature described above but also the kiln rotation speed (in the case of a fluidized bed furnace, the supply speed of the object to be processed and the aeration speed of the flowing gas). Is preferred. For example, when the waste 20 contains a large amount of combustible materials that require time for combustion, such as waste tires, the pretreatment process takes a relatively long time.
[0028]
After the heat treatment process described above, the workpiece 21 is sent to the sorting and collecting process. That is, as shown in FIG. 3, the workpiece 21 that has been subjected to the heat treatment in the pretreatment heating furnace 1 is taken out and put into the sorting device 8. The sorting device 8 includes a first sorting device 8A mainly for sieving and a second sorting device 8B mainly for classification. The workpiece 21 after the heat treatment is first put into the first sorting device 8A. Since the workpiece 21 to be charged has been subjected to the above-described heat treatment, it is sufficient to divide it by size, for example, to separate metal and ash or earth and sand. In some cases, it may be configured. Here, the workpiece 21 is classified up and down by, for example, 30 mm. The large-diameter object 23 discharged from the sieve is mostly metal if the object 21 is wet ash from a waste incineration facility. And since it dried well by the above-mentioned heat processing and the dry ash was shaken off by said 1st sorter | selector 8A, a metal is taken out in the state which hardly adheres. Therefore, when there is no large-diameter object 23 other than metal, the second sorting device 8B described later may not be used. When the workpiece 21 is dumped waste, the large-diameter object 23 often includes waste tires that are combustible materials, tile pieces or concrete pieces that are non-combustible materials, and the first sorting device 8A. The large-diameter object 23 separated in (1) is input to the crusher 9 as necessary, and the object to be processed 21 after adjusting the size is input to the second sorting device 8B. The second sorting device 8B may be a known magnetic sorting device that can sort and separate iron, aluminum, and copper by magnetic force. As a result, the metal can be reliably separated and recovered with almost no foreign matter adhering thereto. In addition, according to the conventional method, for example, when sorting waste disposal, specific gravity sorting (wind sorting) is required to separate pieces of paper, cloth, and the like. Since the piece of paper or the piece of cloth is burned and gasified, such sorting is not necessary for the workpiece 21 in this sorting step.
[0029]
The object to be processed 21 taken out from the sieve of the first sorting device 8A is a melting process step together with the large-diameter object 23 after the metal is separated by the second sorting device 8B or the size of which is crushed and adjusted in size. To serve. In this melting process, the workpiece 21 is put into the waste melting furnace 10 to perform a melting process. As the waste melting furnace 10, a surface melting furnace that generates high-temperature gas in a reducing atmosphere in the main chamber and heats and melts the deposition surface of the workpiece 21 to be deposited can be used. The molten slag 25 taken out by heating and melting can be landfilled as it is. In the waste melting furnace 10, the dust 24 collected by the dust collector 4 provided in the flue 2 of the pretreatment heating furnace 1 is also melted together. The dust 24 includes incinerated fly ash, which is an object to be processed 21 scattered during the heat treatment. Similarly to the flue 2 of the pretreatment heating furnace 1, the gas cooling device 12, the dust collector 13, the exhaust gas treatment device 14, and the ventilation equipment 15 are arranged in this order in the flue 11 of the waste melting furnace 10. Then, the exhaust gas is discharged from the chimney 7 into the atmosphere. The molten fly ash 26 collected by the dust collector 13 may contain harmful substances such as harmful metals and dioxins, and after being subjected to detoxification treatment such as chelation treatment, it is landed together with the molten slag 25. dispose.
[0030]
[Another embodiment in the first embodiment]
An embodiment of the waste melting method according to the present invention not shown in the first embodiment will be described below.
[0031]
<1> In the first embodiment, it has been described that the object to be processed received in the melting processing facility is first subjected to size selection, and the coarse object is crushed, but the object to be processed is waste. If it is from an incineration facility, you may heat-process as it is, without selecting especially. The size selection may be performed by visual inspection, and if a coarse workpiece is found, it may be taken out. Depending on the properties of the coarse material, it may be heat-treated without being crushed, and depending on the quality, it may be disposed as landfill. For example, if the coarse product is flammable, it is not necessary to crush it if it can be put into the pretreatment heating furnace as it is. However, even if it is flammable, it should be heat-treated after being crushed as long as it takes time for combustion like a waste tire.
[0032]
<2> In the first embodiment, it is assumed that the pretreatment conditions are selected according to the properties of the received workpiece, and any of the first pretreatment conditions, the second pretreatment conditions, and the third pretreatment conditions is selected. However, the preprocessing conditions to be selected are not limited to the above three conditions, and may be only two conditions of the first preprocessing condition and the third preprocessing condition. The fourth pretreatment condition may be added, or more pretreatment conditions may be added, and one of the four pretreatment conditions may be selected.
[0033]
<3> In the first embodiment, the first pretreatment condition is a heating temperature of 200 to 400 ° C., the second pretreatment condition is a heating temperature of 550 to 700 ° C., and a third pretreatment condition. Although processing conditions explained the example whose heating temperature is 850-900 ° C, this is an illustration, and if the conditions which dry a processed material and the conditions which burn a processed material are set at least, Good. Accordingly, each pretreatment condition may be a pretreatment condition that defines not only the heating temperature but also the temperature such as the heat treatment time.
[0034]
<4> In the first embodiment, the molten slag taken out from the waste melting furnace is landfilled as it is, and the molten fly ash collected by the dust collector provided in the flue of the waste melting furnace is After detoxifying by chelating treatment or the like, it has been described that landfill disposal is performed in the same manner as the molten slag. However, the molten slag may be reused for road pavement aggregate, lightweight cement aggregate, and the like. The molten fly ash may be rendered harmless, and then charged again into the waste melting furnace to be melted and taken out as molten slag. The means for detoxifying the molten fly ash is not limited to chelate treatment, and any detoxification means may be selected.
[0035]
<5> In the first embodiment, a rotary kiln type heating furnace is used as the pretreatment heating furnace for the heat treatment process, and combustion air is supplied into the furnace as necessary. However, the pretreatment heating furnace may be another type of heating furnace, for example, a fluidized bed furnace may be used as the pretreatment heating furnace. In this case, it is preferable to appropriately size the object to be processed, such as crushing, before the heat treatment step, but it is also sized to some extent in the furnace. In this type of furnace, coarse material is taken out from the bottom of the fluidized bed, but if the object to be treated does not contain non-metallic coarse material, only the metal can be separated and collected before the subsequent sorting and collecting step. . Accordingly, in the sorting and collecting step, it is only necessary to sort iron, aluminum, copper and the like. In addition to the fluidized bed furnace, a multistage roasting furnace, a tunnel furnace, or the like can be used as the pretreatment heating furnace.
[0036]
<6> In the first embodiment, a gas cooling device, a dust collecting device, an exhaust gas treatment device, and ventilation equipment are arranged in this order in the flue leading the exhaust gas from the pretreatment heating furnace, Assuming that exhaust gas is discharged from the chimney into the atmosphere, a bag filter is given as an example of the dust collector, and an activated carbon adsorption tower is given as an example of the exhaust gas treatment device, but the configuration of equipment provided for this flue is different. It may be. Further, a waste heat boiler may be provided as the gas cooling device.
[0037]
<7> In the first embodiment described above, when a material to be processed before being put into the pretreatment heating furnace contains a coarse material having a predetermined size or more, the coarse material is put into a crusher. Although the example which adjusts the to-be-processed object to the size of 300 mm or less by crushing was demonstrated, this size is adjusted according to the characteristic of a pretreatment heating furnace, The said pretreatment heating is carried out without crushing. It may be put into the furnace, may be adjusted based on a size of 300 mm or more, and may be adjusted based on a size different from the exemplified size. This size is preferably small, and the crushing power can be reduced. Moreover, when a coarse thing is a combustible thing, since it can incinerate in the said pretreatment heating furnace, you may throw in into the said pretreatment heating furnace, without crushing.
[0038]
<8> In the first embodiment, the sorting device that performs the sorting and collecting step is divided into a first sorting device that is a classifying means exemplified by a vibrating sieve and a second sorting device that is a metal sorting means. Although the example which comprises is demonstrated, when the above-mentioned pre-processing heating furnace is comprised with a fluidized bed furnace, the said sorting apparatus may be comprised only with said 2nd sorting apparatus.
[0039]
<9> In the first embodiment, the gas cooling device, the dust collector, the exhaust gas treatment device, the flue of the waste melting furnace, as well as the flue of the pretreatment heating furnace, Although it has been described that the ventilation equipment is arranged in order and the exhaust gas is discharged from the chimney into the atmosphere, each equipment provided in the flue may be different, and the configuration thereof is arbitrary. For example, an exhaust gas neutralizing device may be attached to the gas cooling device. Moreover, the temperature of the exhaust gas passing through the dust collector may be increased, and a low melting point metal recovery device may be attached to the exhaust gas treatment device. With such a configuration, it is possible to return the molten fly ash to the melting treatment furnace and discharge it as molten slag. Moreover, the form of the waste melting furnace is also arbitrary, and besides the surface melting furnace, a swirling melting furnace, a fluidized bed type melting furnace or the like can be arbitrarily selected.
[0040]
[Second Embodiment]
An example of an embodiment of the waste melting method according to the present invention will be described below with reference to the drawings.
[0041]
In this second embodiment, a system for efficiently recovering iron contained in waste (generic name for iron ingot, iron piece, iron powder, etc.) will be described. This system efficiently removes iron free from impurities from the waste to be treated in the process until the final disposal of the dumped waste obtained by digging up the landfilled dumped waste. It is a specific example which enables the process for collection | recovery.
[0042]
Prior to the heat treatment of the workpiece 30, this system includes a workpiece containing a large amount of iron with a predetermined particle size or less by a combination of sieving, crushing, and magnetic sorting in the preliminary treatment step shown in FIG. 4. 30, the workpiece 30 containing a large amount of iron is heated in a heating process comprising a rotary kiln 63 shown in FIG. 5, and a sorting and collecting process comprising a vibration sorting device 66 and a magnetic sorting device 67. The order of processing is set to perform sorting.
[0043]
In other words, in the preliminary treatment, the object to be treated 30 (including incinerated main ash and / or incinerated fly ash carried in from a plurality of waste incineration facilities) is made of dumped waste that has been dug up and disposed of in landfilled dumped waste. A receiving pit P <b> 1 that accommodates the object to be processed 30), and the object to be processed 30 accommodated in the receiving pit P <b> 1 uses a loading crane 31 to screen and sort a plurality of vibration types. It is supplied to the grizzly sorter 32. The grizzly sorter 32 is configured to allow leakage of particles having a particle size of about 300 mm or less, and the processed material 30 in a roughly sorted state that has leaked through the grizzly sorter 32 further includes a rotary screen sorter 33 that performs sieve sorting. To be supplied. The screen sorting device 33 is configured to allow leakage of particles having a particle size of about 30 mm or less, and the material 30 to be processed is sequentially transported by a plurality of incombustible material conveyors 34 and supplied to the incombustible magnetic force sorting device 35. Is done. This incombustible magnetic force Sorting The device 35 has a performance (an example of a magnetic force sorting process) for selecting a workpiece 30 containing a large amount of iron by using an attractive force generated by a magnetic force of a magnet provided in a drum 35A driven and rotated around a horizontal axis. The workpiece 30 containing a large amount of iron is sent from the intermediate conveyor 36 to a plurality of pretreatment conveyors 37, and is sent to the foreign matter pit Px via the deodorizing damper 38. Further, the remaining object 30 that has not been subjected to the action of magnetic force is sent to the incombustible pit Py via the deodorizing damper 38. Then, as will be described later, iron is separated and collected from the workpiece 30 sent to the foreign matter pit Px.
[0044]
The workpieces 30 that do not leak through the plurality of grizzly sorting devices 33 are supplied to a two-axis shearing crushing device 41 by being conveyed by a plurality of coarse conveyors 40. The crushing device 41 has a function of roughly crushing the workpiece 30 and discharges those that cannot be crushed such as stone blocks. The to-be-processed object 30 of the rough crushing state crushed by this crushing apparatus 41 is sent to the rough crushing conveyor 42, and the to-be-processed object 30 conveyed by this rough crushing conveyor 42 is the 2nd combustible material from the 1st combustible material conveyor 43A. It is sequentially transported to the conveyor 43B and the third combustible material conveyor 43C and sent to the idler crusher 44. The first combustible material conveyor 43 </ b> A is also supplied with an object to be processed 30 that does not leak through the screen sorting device 33, and this object to be processed 30 is also sent to the idler crusher 44.
[0045]
Further, a metal detector 45 is provided on the transport path of the first combustible material conveyor 43A, and a path switching device 46 is provided at an intermediate position between the first combustible material conveyor 43A and the second combustible material conveyor 43B. When a metal lump inappropriate for crushing is detected by the metal detector 45, the metal lump is discharged by switching the path switching device 46.
[0046]
The idler crushing device 44 includes a hopper 44B having a supply conveyor 44A at the bottom, a crushing unit 44C for crushing the workpiece 30, and a discharge unit 44F having a discharge conveyor 44D at the bottom. 44C has a performance of performing a crushing process so that the particle size becomes about 30 mm and sending it to the discharge unit 44F, and a non-crushable material such as a stone block is discharged on the upper side from the crushing unit 44C. Further, the workpiece 30 crushed by the idler crushing device 44 is supplied to the combustible magnetic force sorting device 47 by the discharge conveyor 44D.
[0047]
This combustible magnetic force Sorting The apparatus 47 has a performance (an example of a magnetic force sorting process) for selecting a workpiece 30 containing a large amount of iron by using an attractive force generated by a magnetic force of a magnet provided in a drum 47A that is driven and rotated around a horizontal axis. The workpiece 30 containing a large amount of iron is sent to the pretreatment conveyor 37 through a path indicated by * a in FIG. In the same manner as above, it is sent to the foreign matter pit Px. Further, the remaining object to be processed 30 is sorted by particle size by the combustible screen sorting device 48, and the object to be treated 30 leaking through the combustible screen sorting device 48 is sent to the fourth combustible material conveyor 43D, The final sorting (an example of the magnetic sorting process) is performed by the final magnetic sorting device 49 disposed at the conveyance end of the fourth combustible material conveyor 43D. Then, the workpiece 30 attracted by the magnetic force by the final magnetic sorting device 49 is sent to the intermediate conveyor 36 via a path indicated by * d in FIG. Is sent to the foreign matter pit Px, and the remaining object 30 that has not been attracted by the magnetic force is supplied to the combustible pit Pz via the deodorizing damper 38. In addition, the object to be processed 30 that does not leak through the combustible screen sorting device 48 is returned to the first combustible material conveyor 43A through a path indicated by * f in FIG.
[0048]
A cyclone type dust collecting device 51 that sucks and collects floating dust of relatively large particles generated at the discharge part of the idal type crushing device 44 is provided, and fine particles in the air sucked by the dust collecting device 51 are collected. A bag filter 52 that removes and removes suspended particulates generated at a plurality of suction points disposed in each part of the system is provided, and a blower 53 that sucks air from the bag filter 52, and an activated carbon deodorant The dust removal system is configured by being arranged with the device 54. Further, in this dust removal system, the dust collected by the dust collector 51 is returned to the second combustible material conveyor 43B through a path indicated by * e in the drawing with a delivery point and a reaching point, and the bug filter 52 The fine dust collected in (1) is transported by a plurality of dust conveyors 55 and sent to the incombustible pit Py via a path indicated by * c in the drawing where the delivery point and the arrival point are indicated.
[0049]
In this treatment system, the platform includes a general waste pit P2 for storing general waste and a special waste pit P3 for storing waste containing a large amount of iron products. The object 30 is directly fed into the idal crushing device 44, and the object 30 to be processed from the special waste pit P3 is sent to the pretreatment conveyor 37. Then, as is clear from the processing flow of the figure, the object 30 obtained by crushing the object 30 mainly from the general waste pit P2 is stored in the combustible pit Pz, and the special waste pit is stored. The object 30 from P3 is stored Px in the foreign matter pit, the object 30 from the receiving pit P1 is selected based on the particle size, and the one containing a large amount of iron is selected by magnetic force sorting to the foreign substance pit Px. The system is formed so as to store and store, in the incombustible pit Py, the remainder that does not contain iron in the workpiece 30 from the receiving pit P1.
[0050]
Although not shown in the drawings, the object to be treated 30 collected and stored in the incombustible pit Py and the combustible pit Pz is finally slag by a melting process using a rotating surface melting furnace or the like, and is slag by a crushing process. After the copper and aluminum contained in is taken out, it is reused as a covering material for landfill and an aggregate for concrete products.
[0051]
Next, a process of selecting and collecting iron (generic name of iron ingot, iron piece, iron powder, etc.) from the workpiece 30 stored in the foreign material pit Px will be described with reference to FIG. In this processing, the workpiece 30 accommodated in the foreign matter pit Px is sent to the input conveyor 62 through the hopper 61 using the crane 60, and the workpiece 30 conveyed by the input conveyor 62 is supplied to the rotary kiln 63. Then, heat treatment is performed at a temperature of 900 ° C. or higher (an example of a heat treatment step). The rotary kiln 63 constitutes a main part in the heat treatment process. The rotary kiln 63 is a rotary kiln 63A that rotates about a horizontal axis, a burner 63B that supplies a combustion hot gas to the kiln 63A, and a workpiece 30 that is forcibly supplied to the kiln 63A. The workpiece 30 that is configured to include the pusher 63C and the combustion chamber 63D and is heat-treated in the rotary kiln 63 is sent from the cooling conveyor 64 disposed below the combustion chamber 63D to the transport conveyor 65. A vibration sorting device 66 that performs specific gravity sorting by vibration is disposed at the lower conveyance position of the conveyor 65, and the workpiece 30 sorted by the vibration sorting device 66 is sent to a plurality of magnetic sorting devices 67. The sorting device 67 separates the iron component and the residue component, and the iron component is collected and transported to the iron conveyor 68 (an example of a sorting and collecting step). In addition, the iron collected by the iron conveyor 68 is collected in a vehicle 75 such as a truck, and can be transported to a facility for reuse. The residue in the object 30 is collected in a vehicle 76 such as a truck. Then, it is returned to the incombustible pit Py and can be melted.
[0052]
The rotary kiln 63 is provided with an air supply system 70 for supplying combustion air in a preheated state, and a gas cooling tower 71 for cooling the combustion gas in the flue from which the combustion gas is discharged from the combustion chamber 63D. The gas cooling tower 71 is provided with a dust conveyor 72 that recovers the fine particles of the object 30 contained in the combustion gas and returns them to the transfer conveyor 65 at the lower part of the gas cooling tower 71. A bag filter 73 for collecting dust contained in the exhaust gas, a reuse of heat of the exhaust gas from the gas cooling tower 71, and a catalyst tower 74 for removing harmful components from the exhaust gas are provided.
[0053]
Since it is configured in this manner, for example, when processing dumped waste obtained by digging up dumped waste disposed of in landfill, this waste waste is sieved (grizzly sorter 32, screen sorter). 33), and a material having a large particle size is crushed (crushed by the crushing device 41 and the idler crushing device 44) to produce a workpiece 30 having a particle size of approximately 30 mm or less. First, a preparatory process for obtaining a workpiece 30 containing a large amount of iron by a magnetic force sorting process (separation process by a nonflammable magnetic force sorting device 35, a combustible magnetic force sorting device 47, and a final magnetic force sorting device 49) is performed to the foreign matter pit Px. To recover. Thus, since the to-be-processed object 30 collect | recovered by the foreign material pit Px has a small particle size, it is easy to convey and the process time can also be shortened also when heat-processing.
[0054]
Next, the object 30 from the foreign matter pit Px is heat-treated with the rotary kiln 63 to remove water contained in the object 30 and facilitate separation of iron and components other than iron. Then, by applying a vibration force in the vibration sorting device 66, separation of iron and components other than iron is promoted, and further, the magnetic sorting is performed by the magnetic force sorting device 67. Therefore, impurities adhering to the sorted iron The amount is extremely small. Then, after iron is collected from the iron conveyor 68 to the vehicle 75 in the workpiece 30 selected by the magnetic force, it can be transported to a facility for reuse and reused. Then, it is returned to the incombustible pit Py and melted so that it can be reused as a covering material for landfill or an aggregate for concrete products.
[0055]
【The invention's effect】
As described above, according to the present invention, an elastic pretreatment process for receiving wastes having basically different compositions in the waste melting furnace can be realized. In particular, prior to the heat treatment of the object to be treated, by obtaining the object to be treated having a predetermined particle size or less and containing a large amount of iron, the iron recovery efficiency is increased, the heating is performed with a rotary kiln, and the iron content is separated by magnetic separation. It will be better recovered.
[Brief description of the drawings]
FIG. 1 is a flowchart showing an example of a waste melting method according to a first embodiment.
FIG. 2 is a conceptual diagram of an example of equipment used for the waste melting method according to the first embodiment.
FIG. 3 is a configuration explanatory diagram of an example of a wide-area melting treatment facility according to the first embodiment.
FIG. 4 is a diagram showing a pretreatment process system according to a second embodiment;
FIG. 5 is a diagram showing a system of a heating process and a sorting and collecting process according to the second embodiment.
[Explanation of symbols]
1 Pretreatment furnace
8 Sorting device
10 Waste melting furnace
16 Heating furnace control mechanism
30 Workpiece
63 Rotary kiln
63A Kiln part
63B burner

Claims (2)

Digging up the waste to be treated in the wide area melting process that melts the incinerated main ash and / or incinerated fly ash carried from multiple waste incineration facilities, or both, or the dumped waste that has been dug up A waste melting method for melting a waste to be processed in a waste disposal process for melting an object individually or in a state where the objects to be processed for both melting processes are mixed,
A heat treatment step for performing heat treatment on the object to be treated, a post-heating sorting and collecting step for selectively collecting metal from the object to be treated after heat treatment, and a melting process for subjecting the object to be treated after separation of the metal to a melting treatment. Process,
Prior to the heat treatment step of the object to be treated, the object to be treated having a predetermined particle diameter or less is taken out by sieving, and the one having a large particle diameter is crushed to be a object to be treated having a particle diameter equal to or smaller than the predetermined particle diameter. Performing a pre-heating magnetic force sorting process to take out the workpiece containing iron by applying a magnetic force to the workpiece obtained by this treatment,
A heat treatment process for performing heat treatment on the workpiece including iron extracted by the pre-heating magnetic force sorting process includes a rotary kiln portion into which the workpiece is fed, and a combustion high-temperature gas to the kiln portion. A waste melting method configured to be performed in a rotary kiln having a burner to be fed. After applying a vibration force to the object to be processed after the heat treatment discharged from the rotary kiln to promote separation of iron and non-ferrous components, iron is separated by applying a magnetic force to the object to be processed. The waste melting method according to claim 1, wherein a post-heating sorting and collecting step is configured.

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