JP2002066499A - Waste treatment method, massive molded item obtained thereby, and waste treatment system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a waste treatment method whereby both a harmful waste and a plastic waste are effectively treated by producing a massive molded item so as to prevent the harmful waste from flowing out into the environment and whereby the life of a storage site for storing the massive molded item is prolonged. SOLUTION: This treatment method has the step of mixing and kneading a harmful waste 47 with a molten plastic waste 41, the step of molding the resultant mixture into a massive molded item 48 by cooling and solidification, and the step of storing the massive molded item 48 in a storage site 49. In the molding step, the mixture is slowly cooled to give the massive molded item 48 having an average particle size of 5 mm or lower. After the molding step, there is the step of treating the surface of the massive molded item 48 to prevent the harmful waste 47 from flowing out.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention can process various kinds of wastes such as general wastes and industrial wastes extremely economically, appropriately and safely while minimizing the influence on the global environment. More specifically, the present invention relates to a waste treatment method, a bulk molded product obtained by the waste treatment method, and a waste treatment system.

[0002] In particular, hazardous wastes including hazardous wastes such as incinerated ash and soot and the like, sludge, contaminated soil, and sludge discharged from incinerators or melting furnaces, etc.
The present invention relates to pollution-free treatment of obtaining and storing a lump-shaped molded product using plastic waste discharged from households and factories.

[0003] Further, a lump-shaped molded product is obtained by using incineration waste and the like generated in an administrative area and plastic waste, and the lump-shaped molded article is constructed in the same administrative area, construction in a civil engineering business, and civil engineering materials. Waste treatment to strongly promote and promote a self-contained self-contained type in an administrative area that reuses both incineration waste and plastic waste by using it as a fuel for melting furnaces. It is about.

[0004] Further, waste containing metal components can be mixed into plastic waste discharged from ordinary households and factories into molten compacts to form bulk moldings, which can be safely stored in large quantities for a long period of time. The present invention also relates to a method for separating and recovering a metal component contained in a massive molded product after stockpiling.

[0005]

2. Description of the Related Art Incinerated ash or dust generated by incineration of industrial waste or general waste in incinerators and soot and dust generated from melting furnaces contain heavy metals and dioxins. If scattered inside, it causes irreversible environmental pollution, and poses a problem as a serious adverse effect on the human body for a long time.

[0006] Wastes such as general wastes and industrial wastes discharged in association with daily activities and business activities are diverse, and wastes which are difficult to incinerate or recycle, residues after incineration or accompanying incineration. Hazardous waste and sludge generated will cause environmental pollution if left arbitrarily.
It is stored semi-permanently in one of the following stable landfills, managed landfills, and closed landfills based on national standards.

[0007] However, with the improvement of living standards and the activation of business activities, the amount of waste discharged is continually expanding, and the remaining years of existing disposal sites are decreasing. For this reason, an attempt has been made to construct a new disposal site, but there is a feeling of inhabitants, the situation is slow, and there is a concern that there is a shortage of disposal sites.

[0008] The present invention provides a waste treatment method capable of effectively treating or disposing of the waste (collectively referred to as treatment), and a waste treatment for technically solving the shortage of the disposal site. One of the objects of the present invention is to provide a method. First, a current waste disposal situation will be described below. (1) Relationship between Waste and Disposal Site FIG. 4 is a process flow showing the relationship between the waste 40 and the disposal site 52. Most of the waste 40 composed of industrial waste or household waste is incinerated in an incinerator 53 or melted in a melting furnace 54. The waste 40 is incinerated in the incinerator 53 to generate soot and dust 44 and incineration ash 45. Further, the waste 40 is subjected to the melting treatment in the melting furnace 54 to generate soot and dust 44. Among them, the soot and dust 44 having a particularly high heavy metal content is prepared by a cement solidification method A as shown in FIG.
Stabilization and immobilization of heavy metals are performed by intermediate treatment such as chemical treatment method B, acid extraction treatment method C, melting treatment method D, and eco-cement treatment method E, and then final treatment at disposal site 52. It is. Regarding the incinerated ash 45, if the concentration of the heavy metal is high, it is desirable to stabilize and fix the heavy metal by the cement solidification treatment method A and then to finally dispose the incineration ash 45 at the disposal site 52.

On the other hand, as shown in FIG. 4, the plastic waste 41 contained in the waste 40 is pulverized into a predetermined shape and then landfilled 59 or incinerated in an incinerator 53. Or melted in a melting furnace 54. Alternatively, the recycling process 60 is performed. In particular, in recent years, the recycling of containers and packaging has progressed, the recovery of plastic waste discharged from general households and the like has progressed, and relatively many attempts have been made to recycle and reuse plastic waste.

[0010] The waste 40 is subjected to the above-mentioned various intermediate treatments in accordance with the type thereof, and is stored in a disposal site 52. Disposal site 5
2 is roughly classified into one of a stable type disposal site, a management type disposal site, and a closed type disposal site.

[0011] Stable disposal sites can store only chemically stable limited waste (5 items) such as glass, set goods, iron and plastic, and their use is limited. Among them, the plastic waste 41 is crushed into a predetermined shape, in other words, it is often disposed of in a bulky state, and the remaining years of the stable disposal site are rapidly disappearing. Weight loss is desired. For this reason, the plastic waste 41 is incinerated, but dioxin may be generated from a large amount of PVC or the like, and it is not so preferable that the amount is gradually reduced. It is conceivable that the waste is compressed and heat is applied to soften it and reduce its capacity, and then disposed of.However, the cost is high, and disposal at a stable disposal site is disadvantageous in terms of cost. It is not at present.

The shut-off type disposal site has a very strict closed structure so that even if waste containing hazardous waste, such as sludge and cinders, is stored as it is, no hazardous waste will exit the disposal site at all. And there are only a small number in a limited place, it is expensive to use,
The facility cannot be used for ordinary waste.

[0013] The controlled disposal site stores intermediately treated waste so that hazardous waste is less likely to be eluted or discharged, and includes a soot and dust 44 obtained as a result of being incinerated in an incinerator 53 or the like, incineration ash. The dust 45 and the dust 44 generated in the melting furnace 54 are stored after being subjected to the above-mentioned intermediate treatment such as the cement solidification treatment method A for preventing the elution of the contained heavy metal. Most of the waste 40 is reduced in volume by this treatment.

[0014] In such a controlled disposal site, even if harmful waste is discharged or eluted, the storage portion is subjected to a water shielding treatment so as not to cause environmental pollution in the surrounding area. It is equipped with a drainage system for collecting and purifying waste, which requires large-scale construction and construction costs, and is installed in a well-located area in consideration of the feelings of the residents. In addition, as will be described later, maintenance costs for scaling up drainage facilities due to calcium salts eluted from storage wastes in large quantities, various types of hazardous wastes eluted from a variety of storage wastes after aging, BOD
Since the cost of large amounts of chemicals, equipment, and operating costs used for detoxifying and removing the COD source and COD source are high, maintenance costs are extremely high.

As described above, the waste 40 is currently stored in the existing disposal site 52, but a large amount of waste 40 is generated.
However, there is a concern that these disposal sites 52 may be insufficient.
Therefore, it is considered to set up a new disposal site, but it is extremely difficult to set up a new disposal site due to the feelings of residents who are concerned about environmental pollution. This means that the stored material can be in various forms (powder,
It is stored in the form of sludge, etc.), so it is unavoidable to give the impression that it is a hazardous waste causing environmental pollution and to give rise to the risk of contamination due to scattering.

[0016] On the other hand, as described above, in combination with the fact that the construction of a final disposal site for incinerated ash or dust is not progressing,
Incinerated ash and soot and dust generated in one area may be disposed of in another area. For example, incineration ash and dust from the Tokyo metropolitan area are transported to southern Kyushu for disposal, and incineration ash from Saitama Prefecture is disposed of in Fukui Prefecture. Transporting a large amount of incinerated ash and soot from one area to another requires a large amount of energy and human resources to be transported. High energy consumption is an important problem to be solved.

[0017] Therefore, in order to reduce the total amount of waste, efforts are being made on a national basis and on a municipal basis to devise ways of living that do not generate garbage itself and to promote recycling by the Container Recycling Law.
In particular, recycling technology for plastic waste is being actively developed, but the technology has not been established and has not become a trump card for waste disposal.

For example, a plastic waste 41 is pulverized, melted, molded, and the use of a recycled product is being studied. .

For example, the Japan Society for Promotion of Plasticity has constructed an experimental plant and tried to regenerate plastic waste discharged as general waste. This recycling of plastic waste separates plastic waste,
It consists of three steps of crushing, melting, and molding the separated plastic waste, and treating the separately collected plastic waste as gravel-like small lump,
Prototypes of remanufactured products, such as bars, were used to study the uses of remanufactured products.

However, the reclaimed product has a relatively low specific gravity, a low compressive strength, and floats on water because its internal structure is porous and porous. Could not be used. In addition, even if mold molding is performed, voids are generated inside the molded product due to insufficient gelling at the time of melting and low pressing pressure to the mold, and the strength of the molded product is insufficient. there were.

Thus, in response to the shortage of the disposal site 52,
At present, we are trying to cope by reducing the amount of waste itself, recycling waste, and establishing new disposal sites, but all are in a deadlock situation.

That is, to date, disposal sites have been viewed only from the viewpoint of the place or equipment for disposing of wastes.
There was no idea to use technical measures for waste storage in order to use the repository effectively.

Therefore, there is a need for a new waste disposal method that can utilize existing disposal sites as effectively as possible. (2) Safety of Intermediate Treatment Method In FIG. 4, most of the waste 40 is incinerated in an incinerator 53, and as a result, dust 44 and incinerated ash 45 containing heavy metals and dioxins are generated, and a small number of molten metals are melted. Dust 54 is generated by the melting process in the furnace 54. In order to stabilize and fix the heavy metals contained, this dust 44 is applied to methods such as cement solidification treatment method A, chemical treatment method B, acid extraction treatment method C, melting treatment method D, and eco-cement treatment method E. Intermediate processing is performed. In the case of the incinerated ash 45, when the amount of hazardous waste is equal to or more than a predetermined reference value, it is desirable to fix the hazardous waste by solidifying cement.

However, the above-mentioned cement solidification treatment method A is a treatment method in which incineration ash 45 or dust 44 is mixed into cement to solidify to obtain a solidified material. If exposed to rainwater or the like for a long time, cracks may occur, and there is a risk that incinerated waste such as soot and dust enclosed therein will flow into the environment at once after a certain period of time. Furthermore, cement solidification method A is inadequate or impossible for the treatment of soot containing high concentrations of heavy metals.

In the above-described chemical treatment method B, there is a chemical treatment method in which a heavy metal contained in incineration waste is stabilized by using a chemical such as an organic chelating agent or an inorganic powder. This chemical treatment method B is not suitable for suppressing elution of dioxins and calcium salts in dust and the like. Further, the organic chelating agent may cause acid rain, soil bacteria, and ultraviolet ray deterioration, and as a result, may cause environmental pollution.

Further, the acid extraction method C tends to have relatively high equipment running costs and has a problem in work safety. As a result, the acid extraction method C is actually employed. There are only two or three treatment plants nationwide. Therefore, the acid extraction method C has a problem in practical utility.

Further, in the melting method D, since the initial cost and the running cost both tend to be relatively expensive, it takes a long period of several decades for nationwide introduction. There is a problem.

Eco-cement treatment method E is a treatment method in which dust and the like are used as a cement material. Cement obtained by the eco-cement treatment method contains a chlorine compound, and its use is limited. Problem.

Further, the above-mentioned solidification treatment method A, chemical treatment method B, and acid extraction treatment method C not only have an insufficient effect of stabilizing dioxins and calcium compounds, but also produce incinerated waste. Because of the need to reclaim land at the final disposal site, the shortage of the final disposal site and the problem of leachate treatment described above are serious, which may lead to a situation where incineration waste is no longer available.

The above-mentioned solidification method A, chemical treatment method B, and acid extraction treatment method C focus on suppressing the elution of heavy metals, and are under recent strict dioxin regulations. Then, the stabilization, immobilization, and, in some cases, detoxification treatment were not sufficient. Furthermore, the melt processing method D and the ecocement processing method E are effective in decomposing and detoxifying dioxin, and may be used effectively, but equipment and running costs are extremely high,
There is no immediate effect because it takes time to spread it nationwide.

Therefore, there is a need for an intermediate treatment method which can be treated at a lower cost than before and which effectively prevents the outflow of dioxin.

On the other hand, incineration ash or soot containing metal components such as heavy metals and heavy metal oxides has been considered so far because the metal components may leak into the environment and cause harm to the natural environment. In order to prevent elution, they were subjected to intermediate treatment by the above-mentioned cement solidification method or chemical treatment method, and then buried in a final treatment plant together with other waste. However, the metal components contained in these incinerated ash and dust may also contain relatively valuable metal components. Therefore, discarding them as it is is a problem from the viewpoint of resource depletion.
Although it has been proposed to recover metal components contained in dust, there is a problem that recycling costs are too high at present and it is difficult to realize efficient recycling. (3) Maintenance and management of disposal sites Stable disposal sites do not inherently elute hazardous wastes, so maintenance and management costs are low. However, managed and closed disposal sites may dissolve hazardous wastes. Therefore, drainage facilities are provided to collect hazardous waste in water discharged from the disposal site (hereinafter referred to as leachate).

As described above, in such a management type disposal site, a storage portion is subjected to a water shielding treatment so as not to cause environmental pollution in the surroundings, and a facility for collecting and purifying harmful wastes from leachate. It requires large-scale construction and construction costs, and is installed in a remote place in consideration of residents' feelings. In addition, maintenance costs for scaling up equipment due to calcium salts eluted from stored waste in large quantities, various kinds of hazardous wastes eluted from a variety of stored waste drugs after aging, BO
Since the large amount of chemicals, equipment, and operating costs used for detoxifying and removing the D and COD sources are expensive,
Maintenance costs are extremely high.

For example, soot and dust generated from municipal garbage incinerators and melting furnaces nationwide reaches about 1.5 million tons annually, of which about 300,000 tons is unreacted used for removing hydrogen chloride in exhaust gas. Slaked lime or other calcium compounds. Calcium compounds contained in large quantities in incineration waste do not disappear in the subsequent intermediate treatment, but are stored in a controlled disposal site and then flow out in large quantities into leachate. Therefore, since these calcium compounds have an adverse effect on the wastewater, pipes and pumps of the purification facility, the cost for removing these is enormous (for example, disposal of 1.5 million m3 of waste is stored). At the venue, it is said to be 1 billion yen / year.)

Therefore, there is a demand for a waste storage method that reduces the maintenance and management costs of the disposal site, and furthermore, a disposal site with a low maintenance cost and a disposal site with a low construction cost are desired. I have. (4) Installation condition of incinerator and melting furnace Although the melting furnace 54 generates dust 44, most of it is converted into molten slag. This molten slag is vitrified,
There is no elution of hazardous waste. Therefore, it is sufficient to perform the melting process using a melting furnace. However, it is said that it takes 10 to 20 years to install a required number of melting furnaces because the number of melting furnaces is extremely small and the construction cost is extremely high. This includes the feelings of the inhabitants, but how to dispose of the waste 40 generated until the required number is installed is a serious problem.

Therefore, there is a demand for a technology capable of storing dust and incineration ash generated from a large number of existing incinerators before the necessary melting furnace is constructed without causing environmental pollution. (5) Recycling In the above situation, even if an efficient storage method for the disposal site 52 is performed, or if the safety of the intermediate treatment is enhanced, a new disposal site may be installed. Because of the limitations, the waste problem cannot be solved unless the waste is recycled and reused.

Therefore, there is a demand for the development of technology that can recycle plastic waste and stored materials, such as soot, stored in managed landfills.

Although recycling of soot and dust using plastic waste has been proposed so far,
No technology can be implemented.

Therefore, there is a demand for a recycling technique that does not elute hazardous waste.

[0040]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and includes incineration ash, dust and the like discharged from incinerators, melting furnaces, and the like, and general households.
Both plastic waste discharged from factories, etc.
It is an object of the present invention to provide a waste treatment method and a waste treatment system capable of effectively treating incineration ash, dust and the like, and plastic waste, while appropriately treating the waste so as not to flow into the environment.

[0041]

According to a first aspect of the present invention, there is provided a waste disposal method comprising: a kneading step of kneading hazardous waste and molten plastic waste; and cooling and solidifying. This is a waste treatment method comprising: a forming step of forming a lump-shaped molded product; and a storage step of storing the lump-shaped molded product in a storage place.

Further, according to a second aspect of the present invention, there is provided a waste disposal method according to the first aspect of the present invention.
The molding step is a waste treatment method in which the average particle size is reduced to 5 mm or less while gradually cooling to obtain a lump-shaped molded product.

Further, according to a third aspect of the present invention, there is provided a waste disposal method according to the second aspect.
A waste treatment method comprising a surface treatment step of performing a surface treatment after the molding step so that the hazardous waste does not flow out to the bulk molded article.

According to a fourth aspect of the present invention, there is provided the waste disposal method according to the first aspect of the present invention, wherein the hazardous waste is hardly removed in the kneading step. This is a waste treatment method in which inorganic powdery particles to be solubilized are mixed.

According to a fifth aspect of the present invention, there is provided the waste treatment method according to the first aspect of the present invention, wherein the oil component is mixed in the kneading step. It is a material processing method.

According to a sixth aspect of the present invention, there is provided a waste disposal method according to any one of the first to fifth aspects, wherein the storage site is a disposal site. It is.

According to a seventh aspect of the present invention, there is provided the waste disposal method according to the first aspect, wherein the harmful waste is incinerated ash, dust, sludge, or the like. Alternatively, it is a waste disposal method that includes at least one of contaminated soils.

Further, according to the present invention, the hazardous waste according to any one of claims 1 to 6, wherein the hazardous waste is one of dust and incinerated ash. A waste disposal method that includes at least one.

Further, according to the ninth aspect of the present invention, there is provided a waste disposal method comprising the steps of: converting a plastic waste and a hazardous waste containing at least one of incinerated ash, dust, sludge and contaminated soil. A waste mixing step of mixing and forming a waste mixture, melting the waste mixture, performing kneading, a melt kneading step of forming a melt kneaded product, extruding the molten kneaded product from an extrusion die, and molding. Extrusion molding step to form a molding by cooling the molding,
A waste treatment method comprising a cooling step of obtaining a lump-shaped molded article and a storage step of storing the lump-shaped molded article in a storage place.

According to a tenth aspect of the present invention, the plastic waste is stored in a warm state from a crusher for crushing the plastic waste. Pneumatic transportation to the first thermal silo by heated air, and hazardous waste containing at least one of incinerated ash, dust, sludge, or contaminated soil, from the ash input hopper into which the hazardous waste is injected, from the hazardous waste A transportation step of pneumatically transporting heated goods to a second thermal insulation silo to store the articles in a thermal insulation state; the plastic waste stored in the first thermal insulation silo; and the hazardous waste stored in the second thermal insulation silo. And a melt kneading process for melting and kneading the waste mixture to form a melt kneaded product. Extruding the melt-kneaded product from an extrusion die, forming an extrusion by molding, a cooling step of cooling the molded product to obtain a lump, and placing the lump in a storage area And a storage step for storing.

Further, in the waste disposal method according to the present invention, the hazardous waste and the molten plastic waste are kneaded and cooled and solidified to form a massive molded product. This is a waste treatment method using a lump-shaped molded product as fuel for a melting furnace.

According to a twelfth aspect of the present invention, there is provided a waste disposal method according to any one of the first to tenth aspects, wherein the bulk molded product is stored in a storage yard. A waste treatment method using the massive molded product as fuel for a melting furnace.

According to a thirteenth aspect of the present invention, in the waste treatment method according to the ninth or tenth aspect, the melting and kneading step includes a feeding part for feeding and remaining heat, and a melting and kneading step. With a twin-screw extruder having a melt-kneading unit for kneading, the waste mixture is melted, and kneaded with a twin-screw arranged rotatably in the cylinder body in the axial direction. This is a waste treatment method which is a melt-kneading process for forming a product.

According to a fourteenth aspect of the present invention, there is provided a waste disposal method according to the first aspect, wherein the plastic waste comprises polyethylene, polypropylene, polystyrene, AS resin,
A waste treatment method that is a general-purpose plastic waste containing at least one of ABS resin, vinyl chloride resin, methacrylic resin, polyethylene terephthalate, polyvinylidene chloride, ethylene vinyl alcohol copolymer, ACS resin, ASA resin and AES resin. is there.

According to a fifteenth aspect of the present invention, there is provided the waste disposal method according to any one of the first to thirteenth aspects, wherein the plastic waste comprises a vinyl chloride waste and a chloride waste. This is a waste disposal method that is plastic waste separated from plastic waste that does not contain vinyl.

According to a sixteenth aspect of the present invention, there is provided a waste disposal method according to any one of the first to fifteenth aspects, wherein the plastic waste is mixed with the hazardous waste. Is a waste treatment method having a weight ratio of 1: 0.25 to 1: 4.

According to the present invention, there is provided a waste disposal method according to the present invention.
In the invention according to any one of Items 2 to 16, the storage site is a waste disposal method for storing only the massive molded product.

Further, according to the present invention as set forth in claim 18, in the invention according to any one of claims 1 to 17, the bulk molded product may have a mass, a volume or a shape. This is a waste treatment method that differs in at least one of them.

Further, according to the present invention, the bulk molded product according to the present invention comprises plastic waste, incineration ash,
It is a lump-shaped molded product obtained by mixing with hazardous waste containing at least one of soot, sludge and contaminated soil, melt-kneading, extruding from an extrusion die, molding and cooling.

According to a twentieth aspect of the present invention, there is provided a lump-shaped molded article according to the nineteenth aspect, wherein the lump-shaped molded article has an average particle size of 5 mm or less. .

According to a twenty-first aspect of the present invention, there is provided the massive molded product according to the present invention, wherein the hazardous waste does not flow out to the surface of the massive molded product. It is a lump-shaped molded product that has been subjected to surface treatment.

[0062] According to the present invention as set forth in claim 22, the lumpy molded product according to the present invention is characterized in that the hazardous waste is hardly contained in the lumped molded product. It is a lump-shaped molded product containing an inorganic powdery material to be solubilized.

According to a twenty-third aspect of the present invention, there is provided a bulk molded product according to the present invention, wherein the bulk molded product contains an oil component. It is a molded product.

[0064] Further, according to the invention as set forth in claim 24, the mass formed product according to the present invention is characterized in that the plastic waste and the hazardous waste are mixed with each other. , Which are 1: 0.25 to 1: 4 by weight.

Further, the waste treatment system according to the present invention, as set forth in claim 25, converts plastic waste and hazardous waste containing at least one of incinerated ash, dust, sludge and contaminated soil. A waste mixing means for mixing and forming a waste mixture, a melting and kneading means for melting and kneading the waste mixture and forming a melt and kneaded substance, and extruding and shaping the molten and kneaded substance from an extrusion die. A waste treatment system comprising: an extrusion molding means for forming a molded product by cooling; and a cooling means for cooling the molded product to obtain a bulk molded product.

Further, in the waste disposal system according to the present invention, the plastic waste is stored in a warm state from a crusher for crushing the plastic waste. Pneumatic transportation with heated air to the first thermal silo, incineration ash,
Hazardous waste containing at least one of soot, sludge or contaminated soil, from an ash input hopper into which the hazardous waste is charged, to a second heat insulation silo in which the hazardous waste is stored in a heated state, and heated air is used. Transport means for transporting, the plastic waste stored in the first thermal silo, and waste mixing means for mixing the hazardous waste stored in the second thermal silo to form a waste mixture, A melt kneading means for melting and kneading the waste mixture to form a melt kneaded product; an extrusion molding means for extruding the molten kneaded material from an extrusion die and molding to form a molded product; and And a cooling means for obtaining a lump-shaped molded product.

According to a twenty-seventh aspect of the present invention, in the waste disposal system according to the twenty-seventh aspect, the first heat-keeping silo includes a first can for storing the plastic waste. And a first steam pipe wound around the outer surface of the first can body and through which steam flows, and wherein the second heat retaining silo stores the hazardous waste. And a second steam pipe wound around the outer surface of the second can body and through which steam flows.

According to a twenty-eighth aspect of the present invention, there is provided a waste treatment system according to any one of the twenty-fifth to twenty-seventh aspects, wherein the melt-kneading means is configured to supply and perform residual heat. Part and a twin-screw extruder having a melt-kneading part for performing melting and kneading, the waste mixture is melted, and kneaded with a twin-screw arranged rotatably in the cylinder body in the axial direction. This is a waste treatment system which is a melt-kneading means for forming a melt-kneaded material.

Further, according to the present invention as set forth in claim 29, in the waste disposal system according to any one of claims 25 to 28, the plastic waste is made of polyethylene, polypropylene, polystyrene, A
Waste that is general-purpose plastic waste including at least one of S resin, ABS resin, vinyl chloride resin, methacrylic resin, polyethylene terephthalate, polyvinylidene chloride, ethylene vinyl alcohol copolymer, ACS resin, ASA resin, and AES resin It is a processing system.

According to a thirty-fifth aspect of the present invention, in the waste disposal system according to any one of the twenty-fifth to twenty-ninth aspects, the waste mixing means includes the plastic waste and the plastic waste. A waste treatment system wherein the mixing with the hazardous waste is 1: 0.25 to 1: 4 by weight.

According to a thirty-first aspect of the present invention, in the waste disposal system according to the thirty-first aspect, after obtaining the mass-formed product, the mass-molded product is obtained. This is a waste treatment system having a storage means for storing materials in a storage place.

Further, according to the present invention, there is provided a waste disposal method comprising at least one of incinerated ash, dust, sludge, and contaminated soil generated in an administrative area. And a waste mixing step of mixing a plastic waste generated in the administrative area to form a waste mixture, and a melt kneading step of melting and kneading the waste mixture to form a molten kneaded product. Extruding the melt-kneaded product from an extrusion die and forming the molded product by molding, a cooling process of cooling the molded product to obtain a bulk molded product, And a storage step of storing the waste at a storage site in the wastewater treatment method.

According to a thirty-third aspect of the present invention, there is provided a waste disposal method according to the thirty-second aspect, wherein the plastic waste is made of polyethylene, polypropylene, polystyrene, AS resin, ABS resin. This is a waste treatment method that is a general-purpose plastic waste containing at least one of vinyl chloride, vinyl chloride resin, methacrylic resin, polyethylene terephthalate, polyvinylidene chloride, ethylene vinyl alcohol copolymer, ACS resin, ASA resin and AES resin.

Further, in the waste disposal method according to the present invention, as described in claim 34, the waste containing a metal component and the molten plastic waste are kneaded, and cooled and solidified to form a block. This is a waste disposal method in which after collecting the bulk molded product, the metal component is recovered from the bulk molded product.

[0075]

BEST MODE FOR CARRYING OUT THE INVENTION
The method includes a kneading step of kneading harmful waste and molten plastic waste, a forming step of cooling and solidifying to form a lump, and a storing step of storing the lump in a storage. Since molten plastic waste is used, the volume of plastic waste can be reduced,
Furthermore, since the molten plastic waste and the hazardous waste are kneaded and cooled and solidified to form a lump-shaped molded article, the lump-shaped molded article is prevented while preventing scattering, outflow and elution of the hazardous waste. Can be stored in the storage area. Therefore, both hazardous waste and plastic waste can be treated while preventing environmental pollution.

In the forming step, it is preferable to form a lump-shaped product by reducing the average particle size to 5 mm or less while gradually cooling. By setting the average particle size of the bulk molded product to 5 mm or less, the bulk specific gravity of the bulk molded product can be reduced, and the bulk specific gravity of the bulk molded product can be reduced. The filling rate can be improved. In addition, the average particle size of the bulk molded product is 5
By setting the diameter to be equal to or less than mm, kneading and dispersion of the massive molded product can be improved. That is, the kneading and dispersion of the hazardous waste and the plastic waste can be improved. In addition, by setting the average particle size of the massive molded product to 5 mm or less, the handleability, transportability, and workability of the massive molded product can be improved. Furthermore, by setting the average particle size of the massive molded product to 5 mm or less, the drop strength of the massive molded product can be improved. In addition, by setting the average particle size of the block-shaped product to 5 mm or less, it is easy to process the block-shaped product so as not to have a fractured surface. further,
If the average particle size of the lump is 5 mm or less, when the lump is put into the melting furnace, the lump is injected instantaneously and continuously by air pressure from the horizontal inlet of the melting furnace. You can do it. Therefore, the bridging phenomenon in the feed pipe due to the melting of the massive molded product due to the high temperature in the melting furnace can be prevented. Further, when the average particle size of the massive molded product is 5 mm or less, when the massive molded product is put into the melting furnace, it is easy to gasify instantaneously in the lower part of the melting furnace. That is, since the specific surface area of the massive molded product is large, the massive molded product is instantaneously gasified in the melting furnace and instantaneously emits strong thermal energy, so that the melting efficiency can be improved. . The fact that the average particle size of the massive molded product is 5 mm or less means that the material passes through a sieve made of a 5 mm mesh defined by JIS standards.

In the forming step, it is more preferable that the average particle diameter is controlled to 3 mm or more and 5 mm or less while cooling slowly. If the average particle size of the block-shaped product is smaller than 3 mm, the production efficiency of the block-shaped product may be reduced, and the handleability of the block-shaped product may be reduced. Furthermore, when the average particle size of the block-shaped molded product is 3 mm or less, the surface of the block-shaped molded product is abraded by rubbing between the block-shaped molded products, the surface is scratched, and harmful waste flows into the environment. This is because there is a possibility of doing so.

In the molding step, it is necessary to reduce the average particle size of the bulk molded product to 5 mm or less while cooling slowly. This is because, even when the average particle size is 5 mm or less, the hazardous waste can be firmly sealed in the bulk molded article by slow cooling.

As a method of cooling the massive molded product, there is a method of cutting the massive molded product while spraying water. However, when water is sprayed, there is a possibility of rapid cooling. Therefore, it is preferable to adopt a method of cutting a massive molded product while spraying oils heated to such an extent that the plastic resin does not solidify. The temperature of the oils to be sprayed is 100
It is preferable that the temperature is 150C. 100-150 ° C
By spraying oils in the temperature range of, even if the hazardous waste contains polypropylene, polyethylene, polystyrene, etc., their softening points are 120 to
At 130 ° C., cooling and solidification of the plastic resin can be prevented. In addition, this makes it possible to prevent the lump-shaped molded product from clinging to the cutter during the cutting, while gradually cooling the lump-shaped molded product.

Here, the slow cooling means 1.5 to 1.5 times per second.
It refers to lowering the temperature of the block at 2.5 ° C. In addition, when the average particle diameter of the massive molded product is 5 mm or less, the massive molded product has a pellet-like shape, and thus the massive molded product can be expressed as a granular molded product.

The cutting method for reducing the average particle size of the block-shaped molded product to 5 mm or less can be an ordinary cutting method such as an air-cooled strand method, an underwater cutting method, a hot cutting method, and a mist cutting method.

[0082] After the molding step, it is preferable to have a surface treatment step of performing a surface treatment on the bulk molded article so that the hazardous waste does not flow out. In the surface treatment step, the surface of the massive molded product can be treated using an aqueous solution of aluminum sulfate. In other words, by immersing the lump in the aluminum sulfate aqueous solution, even if the lump is attached to the surface of the lump, the hazardous waste can be chemically transformed into an insoluble compound. . For example, when a strong alkaline dust containing a large amount of calcium hydroxide is contained as a hazardous waste, the effect of suppressing the elution of heavy metals is obtained by lowering the pH, and colloidal aluminum hydroxide and calcium sulfate are formed. By doing so, hazardous waste can be physically adsorbed. These colloidal substances precipitate when left in water, but can be separated from water by using a coagulant or a filter press. When it is separated from water, it can be brought to the final disposal site by air drying or solidifying with cement, so that it is possible to carry out the treatment extremely safely.

When calcium hydroxide is contained in the massive molded product, the surface of the massive molded product is expressed by the following chemical formula.
The result is a coating of insoluble calcium sulfate and aluminum hydroxide.

3Ca (OH) ₂ + Al ₂ (SO ₄ ) ₃ →
As a 3CaSO ₄ + 2Al (OH) ₃ surface treatment step, it is possible to reheat the massive molded product. When a heat extrusion molding machine is used in the molding process of the massive molded product, a fracture surface is formed on the surface of the massive molded product due to kneading conditions, cutting conditions, cooling methods, etc. In some cases, the coating of the plastic resin covering the hazardous waste becomes incomplete. When such a lump-shaped molded article is exposed to rainwater or the like outdoors, hazardous waste may flow out of the lump-shaped molded article into the environment at a level higher than a predetermined standard. Therefore, as a surface treatment step, the lump molded article is reheated to dissolve the plastic resin again, and the hazardous waste is covered with the completely melted plastic resin. In the reheating, it is preferable to heat the massive molding at 180 to 200 ° C. for 4 to 5 minutes.

For the reheating of the massive molded product, it is preferable to use a method of immersing the massive molded product in heated oil, a method of irradiating the massive molded product with far-infrared rays, or the like. By adopting such a method, it is possible to apply heat to the entire block-shaped product. In addition, at the time of reheating, it is desirable that the block-shaped moldings do not stick to each other during the reheating. Therefore, during reheating, it is preferable to use a stirrer, a vibrating sieve, or the like.

[0086] In the kneading step, it is preferable to mix an inorganic powdery particulate which makes the harmful waste hardly soluble. Hazardous waste contained in soot and dust includes inorganic lead, cadmium, mercury, selenium, hexavalent chromium, arsenic,
Hazardous waste can be immobilized in a bulk molded product by mixing inorganic powdery materials which are physically adsorbed or solidified and insolubilized, such as cyan. The inorganic powdery granules are cements, silica,
It is an inorganic powder containing alumina, magnesium, calcium, iron and the like. Further, the inorganic powdery granular material,
A material that does not decompose, dissolve or corrode even at a temperature of about 300 ° C. is preferable. For example, cements are C
It contains aO, SiO ₂ , Al ₂ O ₃ , and Fe ₂ O ₃ , and causes a hydration reaction to be solidified by using kneading water as a solvent.
In the process of solidification, it encloses soot and dust.
As the fine powder mainly composed of silica, a porous crystal mainly composed of SiO ₂ is used. Such a porous body strongly adsorbs heavy metals such as lead. In the case of mixing the inorganic powdery granules in the kneading step, it is preferable that the inorganic powdery granules be contained at 5 to 30% by mass, more preferably 5 to 20% by mass, based on the hazardous waste. It is preferable to include them.

In the kneading step, it is preferable to mix an oil component. By mixing hazardous waste, molten plastic waste and oil components,
The water repellency of the massive molded product can be improved. Because it is possible to improve the water repellency of the massive molded product, even if the massive molded product is exposed to rainwater or the like and has water absorption like PET resin, the hazardous waste dissolves in water It does not flow out. As the oil component, those having water repellency and heat resistance are suitable, and specifically, silicone oil or the like can be used. Silicon oil is KF96.9 from Shin-Etsu Chemical Co., Ltd.
9 or the like can be used. Silicon oil is preferably used as a diluent of about 3 to 5% by mass diluted with water.

By charging the lump into a reduction melting furnace, it is possible to melt soot and dust using the combustion heat of heavy oil and the plastic waste contained in the lump. In addition, the lump-shaped molded product is put into a reduction melting furnace, where the plastic waste in the lump-shaped molding is used as a carbon source for reduction to reduce zinc oxide and lead oxide contained in soot and dust. Then, it can be evaporated as metallic zinc and metallic lead, which can be collected by a dust collector. When the massive molded product is put into the reduction melting furnace, it is preferable that the ratio of hazardous waste to plastic waste is 1: 0.05 to 1: 0.5 by mass.

As an example of a hazardous waste containing a metal component, a steel dust discarded from an electric furnace containing zinc, the steel dust containing about 20% zinc oxide in the Weltz method, which is a dry method, is taken as an example. The following method has been adopted to concentrate and recover zinc from water. That is, when coke and limestone are mixed with steel dust, and the mixture is put into a reduction kiln and heated to 1200 to 1300 ° C. by a heavy oil burner, the dust is melted and turned into slag, but zinc evaporates and is accompanied by combustion gas. At this time, the zinc is oxidized to zinc oxide, and is collected by a dust collector as crude zinc oxide together with other accompanying components. The dust of the crude zinc oxide is washed with water to remove salts and other impurities, and then pelletized by removing the moisture with a heating and drying kiln. Most of the costs incurred in these processes are energy costs, coke as a reducing agent, and limestone to ensure fluidity.However, when the zinc content in dust is low, And costly, resulting in an economically disadvantageous result. 0.5 in the dust
Although it contains about 10% of zinc and lead, it cannot be recovered by conventional methods because it cannot be profitable. Soot and dust are expensive and detoxify heavy metals at high cost. In addition, it was disposed of at a final disposal site.

However, in recent years, the construction of a final disposal site has not progressed and the remaining capacity is imminent due to the strengthening of regulations related to the environment. Therefore, there is a need for a method for effectively using soot and dust without reclaiming it. It has become to.

Thus, the dust and the melted plastic waste are kneaded, cooled and solidified to form a molded product, which is put into a reduction melting furnace, where the combustion heat of heavy oil and the combustion of the plastic waste are added to the melting of the dust. By utilizing heat and using carbon in plastic as a reducing agent, zinc oxide and lead oxide contained in dust are reduced and evaporated as metallic zinc and metallic lead, which are collected by a dust collector. According to this method, zinc and lead in dust can be concentrated 5 to 10 times, so that zinc and lead can be economically recovered from dust having a low content. This makes it possible to safely store the bulk molded product in large quantities for a long period of time and then separate and recover the components contained in the bulk molded product at a profitable cost.

In addition, since dusts in powder, including high-concentration zinc dust generated in a reduction-concentration furnace, are agglomerated and reduced in volume, handling is easy, and transportation costs to a smelter can be reduced. Moreover, storage can be facilitated. Further, coke can be saved because plastic waste is a carbon source necessary for reduction in the reduction melting furnace. The concentration of salts in dust can also be diluted by mixing with the currently accepted steel dust. Further, since plastic waste is used as fuel, heavy oil for heating can be saved. For example, an environmental plant manufacturer estimates that kerosene requires 300 liters of heavy oil to melt 1 ton of ash, but 0.5 tons of plastic waste requires 8 liters of kerosene. In addition, if the molded product is thermally decomposed by a heating furnace provided separately to obtain cracked oil and is used as fuel, heavy oil is not required. Since the dust contains a large amount of CaO, the amount of limestone can be reduced. In addition, silica is added simultaneously with limestone in order to suppress the generation of massive melt generated on the furnace wall, etc.,
This also makes it possible to substitute the silica contained in the dust to some extent. Furthermore, since the residue can be used as molten slag, there is no waste to be disposed at the final disposal site. As described above, the economic effect when the above-described method is adopted is large, and even if the dust content is low, the cost of recovering the metal can be compensated, so that the recovery of the metal from the dust is profitable. It will be.

The storage site can be a disposal site. By kneading the molten plastic waste and the hazardous waste and cooling and solidifying the mixture, it is possible to obtain a reduced-volume molded product. Therefore, the scattering of hazardous waste,
While preventing runoff and elution, the remaining years of the repository can be extended.

The hazardous waste may include at least one of incinerated ash, dust, sludge, and contaminated soil. Soot, incinerated ash, sludge, or contaminated soil has conventionally been stored in a disposal site, and large amounts of small harmful component particles may flow into a drainage facility. The material is kneaded with the molten plastic waste, cooled and solidified to form a lump, so the particles of the harmful components of the harmful waste are firmly enclosed in the lump and flow into the environment. To do so can be highly prevented.

The hazardous waste may contain at least one of dust and incinerated ash. Since the calcium salt contained in the dust or incinerated ash is fixed and stabilized by the molten plastic waste, it can be highly prevented from being eluted into the leachate of the disposal site. Therefore, it is possible to reduce the maintenance of the drainage equipment required for taking measures against the eluted calcium salt as compared with the related art, and it is possible to reduce the maintenance cost. In addition, it is possible to prevent dioxin from flowing out.

Melted plastic waste, incinerated ash,
Hazardous waste containing at least one of dust, sludge, and contaminated soil is kneaded and cooled and solidified to obtain a lump-shaped molded product, and the lump-shaped molded product can be stored in a storage site.

The molten plastic waste and the hazardous waste are kneaded and solidified by cooling to obtain a massive molded product. Therefore, it is possible to prevent the hazardous waste such as dioxin from flowing out of the massive molded product to a high degree. In addition, plastic waste can be reduced in volume. Since the volume reduction processing of the plastic waste can be promoted, the space of the storage site can be effectively used even when the bulk molded product is stored in the storage site. The waste treatment method according to the present invention is to knead a molten plastic waste and a hazardous waste, and to obtain a lump-shaped molded product by cooling and solidifying the plastic waste. By comparison, the volume is about 1/5
The volume can be reduced to some extent. Therefore, it is possible to promote the processing of reducing the volume of plastic waste, and it is possible to achieve effective use of the storage site and, thus, to greatly extend the life of the existing storage site.

Further, since a lump-shaped molded product is obtained by kneading the molten plastic waste and the hazardous waste and cooling and solidifying the same, it is necessary to strongly encapsulate the hazardous waste such as dioxin in the lump-shaped molded product. It is possible to prevent hazardous waste from flowing into the environment. Therefore, it is possible to prevent environmental pollution while treating plastic waste and hazardous waste.

The molten plastic waste and the hazardous waste are kneaded and cooled and solidified to obtain a massive molded product. Therefore, calcium salts from the hazardous waste can be encapsulated in the massive molded product. It is possible to suppress the outflow of calcium salts from waste. Therefore, when storing the massive moldings in the storage, the maintenance cost of the storage associated with the outflow of the calcium salt from the waste can be reduced.

Furthermore, although various kinds of substances are mixed in hazardous wastes, the amount of hazardous wastes and water pollutants discharged from the various substances to the environment is considerably reduced. In addition, since it is possible to reduce the type of the effluent substance itself, it is possible to reduce the maintenance cost of the storage site when storing the bulk molded product in the storage site.

Further, since the hazardous waste can be firmly enclosed in the lump, the outflow of the hazardous waste into the environment can be considerably suppressed, and the form of the lump is solid. Since it is not powdery or granular, there is little possibility of scattering. For this reason, the massive molded product according to the present invention is extremely good for safety, and the consent of the local residents is obtained even if the storage location for storing the massive molded product is provided in the vicinity of the residential area of the peripheral residents. It becomes easier.

Further, the waste disposal method according to the present invention is a waste disposal method which comprises mixing a plastic waste and a hazardous waste containing at least one of incinerated ash, dust, sludge and contaminated soil to form a waste mixture. A material mixing step, melting the waste mixture, performing kneading, a melt kneading step of forming a molten kneaded material, a cooling step of cooling the molten kneaded material, and a cooling step of obtaining a massive molded product, And a storage step of storing the waste in a storage site. After mixing the plastic waste and the hazardous waste to form a waste mixture, the waste mixture is melted and kneaded to form a melt-kneaded product, and the molten kneaded product is cooled, and It is possible to obtain

In the step of obtaining a lump-shaped molded product from the melt-kneaded product, the molten kneaded product is extruded from an extrusion die and molded to form a molded product, and the molded product is cooled to obtain a lump-shaped molded product. It is also possible to obtain a massive molded product by cooling and solidifying in the water tank by putting the melt-kneaded material in a water tank, and also put the melt-kneaded material in a container and put it in the container. It is also possible to obtain a lump-shaped molded product by exposing the melt-kneaded product to room temperature.

Further, the waste disposal method according to the present invention comprises a waste mixing step of mixing a plastic waste and a hazardous waste to form a waste mixture, and melting and kneading the waste mixture. A melt-kneading step of forming a melt-kneaded product, an extrusion molding step of extruding the melt-kneaded product from an extrusion die and molding to form a molded product, and a cooling process of cooling the molded product to obtain a massive molded product. And a storage step of storing the massive molded product in a storage place.

Further, the waste disposal method according to the present invention is a method for removing plastic waste from a pulverizer to a first thermal silo.
While transporting pneumatically with heated air, transporting the hazardous waste from the ash input hopper to the second thermal silo by pneumatic transport with heated air, the plastic waste stored in the first thermal silo, A waste mixing step of mixing the harmful waste stored in the two heat-keeping silos to form a waste mixture, melting the waste mixture, performing kneading, and a melt-kneading step of forming a melt-kneaded product; Extrusion of the melt-kneaded product from an extrusion die and molding to form a molded product; an extrusion process of cooling the molded product to obtain a massive molded product; and storing the massive molded product in a storage area. And a storage step.

In the melt-kneading step, the waste mixture is melted by a twin-screw extruder having a feed section for feeding and preheating and a melt-kneading section for melting and kneading, and is mutually axially inserted into the cylinder body. It is possible to perform a kneading process in which kneading is performed with a biaxial screw rotatably disposed to form a melt-kneaded product.

Further, the waste disposal system according to the present invention comprises a waste mixing means for mixing a plastic waste and a hazardous waste to form a waste mixture, and melting and kneading the waste mixture. A melt-kneading means for forming a melt-kneaded product, and extruding the melt-kneaded product from an extrusion die,
It has an extrusion molding means for forming a molded product by molding, a cooling means for cooling the molded product to obtain a massive molded product, and a storage means for storing the massive molded product in a storage area.

Further, the waste treatment system according to the present invention pneumatically transports plastic waste from a crusher to a first heat-keeping silo with heated air, and transfers hazardous waste from an ash charging hopper to a second heat-keeping silo. Up to this point, the transportation means for pneumatically transporting the heated air, the plastic waste stored in the first thermal silo, and the hazardous waste stored in the second thermal silo are mixed to form a waste mixture. A waste mixing means, a melt kneading means for melting and kneading the waste mixture to form a melt kneaded product, and an extrusion molding method for extruding the molten kneaded material from an extrusion die and molding to form a molded product. Means, cooling means for cooling the molding to obtain a lump, and storage means for storing the lump in a storage area.

Further, as the melt-kneading means, the waste mixture is melted by a twin-screw extruder having a supply section for feeding and remaining heat and a melt-kneading section for melting and kneading.
It is possible to use a melt-kneading means for kneading with a biaxial screw arranged rotatably in the cylinder body in the axial direction to form a melt-kneaded product.

The plastic waste is polyethylene, polypropylene, polystyrene, AS resin, ABS
Resin, vinyl chloride resin, methacrylic resin, polyethylene terephthalate, polyvinylidene chloride, ethylene vinyl alcohol copolymer, ACS resin, ASA resin, AE
It is a general-purpose plastic waste containing at least one of the S resins. Incidentally, the AS resin is a random copolymer obtained by suspending, solution or bulk polymerization of acrylonitrile and styrene. The ABS resin is a copolymer resin composed of three components of acritonitrile / butadiene / styrene, and is a resin having both the characteristics of polystyrene and the characteristics of an AS resin and further increasing their physical property levels. The ACS resin is a three-dimensional polymer using chlorinated polyethylene instead of butadiene as an ABS resin. The ASA resin is a three-dimensional polymer using acrylic rubber instead of butadiene as an ABS resin. The AES resin is a three-dimensional polymer using an ethylene-propylene-diene terpolymer blend (EPDM) instead of butadiene as an ABS resin.

Although the above-mentioned general-purpose plastics do not reach the physical property levels of engineering plastics among thermoplastic resins, they have considerable physical property levels, are excellent in workability, are excellent in balance between the two, and are relatively inexpensive. Therefore, it is used in large quantities on a scale of several hundred thousand to several million tons per year. In particular, polyethylene,
Polypropylene, polystyrene and polyvinylidene chloride are produced in large quantities.

Plastic waste includes natural rubber, natural rubber derivatives, emulsion-polymerized styrene-butadiene rubber, solution-polymerized styrene-butadiene rubber, high cis-butadiene rubber, low cis-butadiene rubber, isoprene rubber,
Disposal of rubber components such as acrylonitrile butadiene rubber, hydrogenated nitrile rubber, butyl rubber, halogenated butyl rubber, chloroprene rubber, epichlorohydrin rubber, chlorosulfonated polyethylene, fluoro rubber, ethylene propylene rubber, acrylic rubber, silicone rubber, urethane rubber and polysulfide rubber Things shall be included.

The hazardous waste contains at least one of incineration ash, dust, sludge, and contaminated soil. The incineration ash or dust is obtained by converting industrial waste or general waste into an incinerator or melting furnace. It is emitted by incineration. The hazardous waste contains hazardous wastes such as lead, cadmium, mercury, hexavalent chromium, selenium, cyanide, arsenic, dioxin, and calcium compounds.

FIG. 3 is a schematic diagram of a waste disposal method according to the present invention. The melting furnace 54 incinerates and melts at a temperature higher than the incineration temperature of the incinerator 53 (1200 ° C. or higher). The amount of is limited. Waste 40
Consists of industrial waste and household waste. Most of the waste 40 is incinerated in an incinerator 53 or melted in a melting furnace 54. As a result of the incineration or melting, the waste 40 generates soot and dust 44 or incineration ash 45 or a mixture thereof. Hazardous waste 47 includes at least one of incinerated ash and dust, and this hazardous waste 47 includes sludge,
It is possible to contain contaminated soil and the like. In addition, it is possible to mix infectious medical waste into the hazardous waste 47, but the most suitable one to be used as the hazardous waste 47 is a dust containing a high concentration of heavy metals.

On the other hand, the waste 40 contains plastic waste 41. This plastic waste 41
Are separated from the waste 40 and mixed with the hazardous waste 47 to form a waste mixture. In addition, as a method of separating the plastic waste 41 from the waste 40, a commonly used method can be used.

The waste kneaded material is heated to melt the plastic waste 41 and kneaded with the hazardous waste 47 to form a molten kneaded material. In this state, an appropriate amount of the melt-kneaded material is taken out, cooled and solidified to form a massive molded product 48.
Get. Alternatively, the melt-kneaded product can be extruded from an extrusion die, molded, and the molded product can be cooled to form a massive molded product 48. In addition, it is also possible to mix the hazardous waste 47 into the place where the plastic waste 41 has been melted in advance, and knead the two to form a melt-kneaded product.

The hazardous waste 47 and the plastic waste 41 are melted and kneaded in a dry state of 1% or less, respectively, at a weight ratio of, for example, 1: 0.5.

The mass 48 can be obtained in this manner, and a system for achieving this is shown in FIG.
Is preferred. The operation will be described later.

Then, the molded product is cooled to obtain a massive molded product 48. The bulk molded product 48 may have any shape, size, and the like, but has a smooth shape such as a sphere having a size of about 5 cm to 10 cm or a rectangular flat plate having no fine protrusions on the outer peripheral surface. In addition, if a plastic having a thickness of about 2 mm completely covers the surface of the molded product, particles such as dust (1 μm to 100 μm) can be used.
m) are dispersed and physically sealed therein. Therefore, this massive molded product 48 is very hard due to plastic, and is in a state that it is extremely hard to be broken.

In the state of the mass 48, harmful wastes such as heavy metal ions and calcium salts contained in dust and the like are firmly sealed inside the mass and eluted into the environment as described later. Alternatively, it is difficult to flow out. Further, since the dioxin adhering to the dust particles is completely surrounded by the plastic, it hardly flows into the environment unless the massive molding 48 is finely pulverized and the dioxin is exposed on the surface.

Therefore, the mass 48 is transferred to the storage 4
9 and can prevent harmful waste from flowing into the environment.

The storage 49 is a temporary storage 50 and a storage 51.
And a disposal site 52.

The temporary storage place 50 is a place where the mass 48 is temporarily placed and placed, and means the most primitive and simple storage facility among the storage places 49. Temporary storage 5
0, for example, after that,
It can be used as the melting furnace fuel 55. That is, the plastic waste 41 and the hazardous waste 47 are mixed to form a waste mixture, the waste mixture is melted and kneaded to form a melt-kneaded material, and the molten kneaded material is cooled to obtain a mixture. The massive molding 48 can be used as a melting furnace fuel 55. When used as the melting furnace fuel 55, most of the hazardous waste becomes molten slag, and the elution of the hazardous waste is further prevented. Moreover, even if dioxin is contained, dioxin is decomposed and made harmless by the high-temperature heat of the melting furnace, so that environmental pollution due to dioxin can be properly prevented.

The temporary storage 50 is a storage facility in which the use of the massive molding 48 is determined, and is temporarily placed before the massive molding 48 is consumed. As described above, the lumpy molded product 48 has a structure in which the hazardous waste is extremely unlikely to flow out. Therefore, even if the storage facility for temporarily storing the hazardous waste is simply configured, the hazardous waste can be found in the environment. The probability of flowing out is extremely low. After being subjected to the melting treatment, the massive molded product 48 used as the fuel of the melting furnace is dropped into a water-cooled pool provided at the lower part of the melting furnace to become a molten slag 58. Since the molten slag 58 is a vitreous substance and the hazardous waste is firmly bound in the vitreous substance, the possibility that the hazardous waste from the molten slag 58 flows into the environment is extremely low. Therefore, the molten slag 58 can be safely used as the civil engineering work material 56.

The storage place 51 is a place where the mass 48 is stored for a certain period of time. The storage space 51 can be configured such that a storage space is formed by an outer wall and the block 48 is stored in the storage space. In addition, storage place 51
It is also possible to adopt a configuration in which a storage space is formed by an outer wall, and a dome-shaped rainwater intrusion prevention portion for preventing infiltration of rainwater into the storage space is provided on the ceiling. In any case, since the hazardous waste hardly leaks out of the bulk molded product 48, the storage space 51 can have a relatively simple configuration, and as a result, economically inexpensive storage is possible. It becomes. Bulk molding 4 stored in storage 51
8 can be stored until its intended use is found. The intended use may be the fuel of the melting furnace. That is, there are many existing incinerators 53, and a large amount of soot and incineration ash is generated from the incinerators 53. On the other hand, since the melting furnace 54 incinerates and melts the waste 40 at a very high temperature, the volume of the waste is greatly reduced by incineration and melting. Since dioxin is completely decomposed in addition to slag, the disposal method of the waste 40 is preferable.

However, the number of existing facilities (about 30) is extremely small compared to the required number (several hundreds), and the construction of the required number of facilities takes a long time of 10 to 20 years. Therefore, the soot and the like that cannot be melted in the melting furnace 54 and incinerated in the incinerator 53 are safely stored so that harmful substances do not flow into the environment.
With the increase in the number of facilities, if the stored mass 48 is used as a fuel for the melting furnace 54, the plastic becomes a fuel, and at that time, the plastic does not generate dioxin due to high temperature. In addition, the enclosed dioxin is decomposed by high temperature, so that hazardous waste can be rendered harmless. In addition, there is no need to enclose in plastic. That is, dust and the like containing harmful waste generated when incinerated in the incinerator 53 are sealed in the lump 48, and the plastic is reused as fuel along with the construction of the melting furnace 54, and the harmful waste is removed. It makes the waste harmless.

The disposal site 52 refers to an existing final disposal site for the waste 40. The disposal site 52 is classified into a stable final disposal site, a managed final disposal site, and a shielded final disposal site. It is possible. As explained in the section of the prior art, the stable final disposal site has a retaining wall for holding waste and an enclosure surrounding the waste, and is constructed with landslide prevention works and subsidence prevention works. Is done. The management type final disposal site has a retaining wall, a fence, drainage facilities such as a water collection facility and a leachate treatment facility, and is constructed with a seepage control, a landslide prevention and a settlement prevention. What is a shielded final disposal site?
It has an enclosure, an internal partitioning device, an outer peripheral partitioning device, a rainwater intrusion prevention part, and the like. Hazardous waste hardly leaks out of the lump 48 and is a relatively safe substance. Naturally, it can be disposed of at the existing final disposal site. However, since the construction of leachate in the stable disposal site is not enough, the lump 48 is cracked after several decades, taking into account the case that heavy metals etc. elute from the inside, As much as possible, the block 48 is not stored here.

However, the block-type disposal site can naturally store the bulk molded product. Waste 40, including hazardous waste, is typically stored in managed landfills. Since this disposal site has measures against leachate and is equipped with a drainage system, even if some heavy metals elute from the lump after several decades, it will be recovered from the leachate Therefore, it does not cause environmental pollution.

It should be noted that if the mass is stored in the disposal site to some extent and the soil is covered (soil covering) every time it is stored to a certain thickness, there is almost no deterioration due to solar radiation, so it is natural that no hazardous waste will flow out. . In addition, since the bulk molded product is hard and does not break into particles, the particles of the stored material are less likely to be mixed in the leachate. Therefore, the amount of sediment that sediments on the sedimentation equipment in the drainage equipment is reduced, and the maintenance cost is further reduced.

As described above, by employing the waste disposal method according to the present invention, the plastic waste 41 and the hazardous waste 47 can be effectively used for stabilization and immobilization, and the plastic waste 41 and the hazardous waste 47 can be effectively used. The object 47 can be processed very safely. further,
Since the massive molding 48 hardly elutes calcium salt, the amount of calcium salt contained in the wastewater discharged from the storage site 49 is naturally small. Therefore, the maintenance and management costs required for treating the calcium salt contained in the wastewater from the storage site 49 can be reduced. Also, by forming the massive molding 48,
The volume of the plastic waste 41 and the hazardous waste 47 can be reduced, the storage site 49 can be formed in a relatively small space, and the life of the existing disposal site 52 can be extended. It becomes. Even if this bulk molding is additionally disposed of in an existing managed disposal site, the maintenance of drainage facilities etc. is simplified and inexpensive for the above reasons, but when a new managed disposal site is established, If only the bulk molding or the bulk molding is stored, the drainage equipment and the like can be reduced in size and simplified, so that construction costs can be reduced and maintenance costs are naturally reduced. .

The bulk molded product 48 can be finally disposed of by storing it in a controlled disposal site, and may be left semipermanently. However, the massive molding once stored may be taken out as the melting furnace 54 increases and used as fuel for the melting furnace 54. Then, the managed disposal site can be used more efficiently. In particular, if only the lump-shaped molded product is stored, the lump-shaped molded product can easily be taken out.

Further, according to the present invention, a product which has been subjected to an intermediate treatment (a chemical treatment method, an acid extraction method, etc.) as in the prior art,
It is good also as a lump molding thing by enclosing with plastic waste.

FIG. 1 is a schematic diagram of a waste treatment system suitable for obtaining the above-mentioned massive molding 48. As shown in FIG. Crusher 2 for crushing plastic waste 41 into flakes
And a first venturi 32 that sucks the crushed and flaked plastic waste 41 from the crusher 2.
And a first cyclone 28 for collecting the flake-shaped plastic waste 41 and a first heat retention for heating the plastic waste 41 crushed and formed into a flake before being melt-kneaded by the twin-screw extruder 1. A silo 4, an ash input hopper 3 into which the toxic waste 47 can be injected, a second venturi 33 that sucks the toxic waste 47 input from the ash input hopper 3, and a second excluding foreign substances from the toxic waste 47 A cyclone 29, a second heat-keeping silo 5 for heating the melt before kneading the hazardous waste 47 with the twin-screw extruder 1, and a warm air from the first venturi 32 to the first cyclone 28. From the pipe P8 for pneumatic transportation, the first fixed-rate feeder 6 for supplying a fixed amount of the plastic waste 41 from the first heat-keeping silo 4 to the twin-screw extruder 1, and the second heat-keeping silo 5 A screw extruder certain amount supplying hazardous waste 47 to 1 second metering feeder 7, wherein the first metering feeder 6
A twin-screw extruder 1 that melts and kneads the plastic waste 41 flowing from the above and the hazardous waste 47 flowing from the second metering device 7 to form a melt-kneaded material, and extrudes the melt-kneaded material into a predetermined shape. Extrusion die 8 for molding to form a molded product
And a cooling water tank 9 for cooling the molded product to form the massive molded product 48, and a storage hopper 10 for storing the massive molded product 48.

The plastic waste 41 crushed into flakes by the crusher 2 is sucked out from the crusher 2 by pneumatic transportation by the first venturi 32 via the pipe P1. Thereafter, the air is transported from the first venturi 32 to the first cyclone 28 via the pipe P2, and is collected by the first cyclone 28. From the first cyclone 28, the flake-shaped plastic waste 41 is temporarily stored in the first heat retaining silo 4. The air recovered from the first cyclone 28 is introduced into the first circulating air heater 24 via the pipe P3 and is heated. First circulation air heater 2
The temperature of the circulating air flowing into 4 can be increased by using waste heat from an incinerator or a melting furnace, and when such waste heat is used, it is very economical. is there. The air discharged from the first circulating air heater 24 is introduced into the first blower 26 via the pipe P5 and forms a flow of circulating air. The circulating air discharged from the first blower 26 flows into the first venturi 32 via the pipe P6, and mixes with the flake-shaped plastic waste 41 pneumatically transported from the crusher 2 via the pipe P1, again,
It flows through the pipe P2.

In the waste disposal system according to the present invention, the plastic waste 41 is replaced with the plastic waste 41.
From the crusher 2 for crushing the plastic waste 41
Since the air is transported by heated air to the first heat-keeping silo 4 where the water is stored in a heat-retained state, it is possible to dry the moisture adhering to the plastic waste 41 at the same time as carrying the air. When the plastic waste 41 containing water flows into the twin-screw extruder 1, the twin-screw extruder 1
When steam is enclosed in the melt-kneaded material during the melt-kneading, there is a possibility that air bubbles are generated in the massive molded product. Further, when the plastic waste 41 containing water flows into the twin-screw extruder 1, hydrochloric acid generated by absorbing hydrochloric acid gas generated in the twin-screw extruder 1 and salts contained in soot and dust are removed. This may cause corrosion of the twin-screw extruder 1. Therefore, the plastic waste 41 is pneumatically transported by the heated air, so that the plastic waste 41 can be dried at the same time as the pneumatic transport, so that such a disadvantage can be prevented. As a dry state of the plastic waste 41, the moisture contained in the plastic waste 41 is preferably 3% by mass or less, more preferably 1% by mass or less.

The hazardous waste 47 input from the ash input hopper 3 is sucked out from the ash input hopper 3 by pneumatic transportation by the second venturi 33 via the pipe P7. Thereafter, the air is transported from the second venturi 33 to the second cyclone 29 via the pipe P8, and is collected by the second cyclone 29. From the second cyclone 29, the hazardous waste 47 is temporarily stored in the second heat retaining silo 5. The air collected from the second cyclone 29 is introduced into the second circulating air heater 25 via the pipe P9 and is heated. The temperature of the circulating air flowing into the second circulating air heater 25 can be increased by using waste heat from an incinerator or a melting furnace. Is very economical. The air discharged from the second circulating air heater 25 is introduced into the second blower 27 via the pipe P11 and forms a flow of circulating air. The circulating air discharged from the second blower 27 is
The ash flows into the second venturi 33 via the pipe 12, mixes with the hazardous waste 47 pneumatically transported from the ash input hopper 3 via the pipe P 7, and flows again through the pipe P 8.

In the waste disposal system according to the present invention, the hazardous waste 47 is transferred from the ash input hopper 3 into which the hazardous waste 47 is charged to the second thermal insulation silo 5 which stores the hazardous waste 47 in a warmed state. Since the air is transported by heated air, the moisture adhering to the hazardous waste 47 can be transported by air and dried at the same time.
As a dry state of the hazardous waste 47, the water content in the hazardous waste 47 is preferably 3% by mass or less, more preferably 1% by mass or less.

A pipe P4 is branched from the middle of the pipe P3, and a first pressure regulating valve 34 is provided in the pipe P4. When the pressure in the pipe increases, the pressure of the circulating air can be maintained at a predetermined value by opening the first pressure regulating valve 34 to exhaust the circulating air from the pipe P4. From the middle of the pipe P9, the pipe P
10 is provided in a branched manner, and a first pressure regulating valve 35 is provided in the pipe P10. When the pressure in the pipe becomes high, by opening the first pressure regulating valve 35,
By exhausting the circulating air from the pipe P10, the pressure of the circulating air can be maintained at a predetermined value.

Pipe P1, pipe P2, pipe P3, pipe P
4. The air temperature of the circulating air flowing through the pipes P5 and P6 is set to 120 to 150 ° C. If the temperature in the circulating air is set higher than 150 ° C,
Flake-shaped plastic waste 41 flowing through the piping
Is likely to melt and adhere to the inner wall of the pipe. When the temperature in the circulating air is set lower than 120 ° C., the flaky plastic waste 41
This is because the effect of drying is not sufficient. On the other hand, pipe P
7, the air temperature of the circulating air flowing through the pipes P8, P9, P10, P11 and P12 is 12
It is set to 0 to 180 ° C. Set the temperature in the circulating air to 1
When the temperature is set to be higher than 80 ° C., if the temperature of the hazardous waste 47 flowing through the pipe is too high, the temperature is too high when the plastic waste 41 is melted and kneaded in the twin-screw extruder, so that the resin becomes too hot. May be decomposed. If the temperature in the circulating air is set lower than 120 ° C., the effect of drying the hazardous waste 47 is not sufficient.

The plastic waste 41 stored in the first thermal insulation silo 4 is stored while being kept at a predetermined temperature. By maintaining the temperature at a predetermined temperature, the temperature can be preliminarily increased before flowing into the twin-screw extruder 1, and therefore, the melt-kneading in the twin-screw extruder 1 is facilitated. The first heat retaining silo 4 has a first can body for storing plastic waste 41, and a first steam pipe wound around the outer surface of the first can body and through which steam flows. Since the temperature of the first can body can be raised from the outside by the steam flowing through the first steam pipe, the plastic waste 41 stored in the first heat keeping silo 4 can be kept warm. The steam flowing through the first steam pipe can use the waste heat of the incinerator or melting furnace, and if waste heat is used, the consumption of heating energy can be suppressed. It becomes possible.

The hazardous wastes 47 stored in the second thermal silo 5 are stored while being kept at a predetermined temperature. The second heat retaining silo 5 has a second can body for storing hazardous waste 47, and a second steam pipe wound around the outer surface of the second can body and through which steam flows. Since the temperature of the second can body can be raised from the outside by the steam flowing through the second steam pipe, the plastic waste 41 stored in the second heat keeping silo 5 can be kept warm. The steam flowing through the second steam pipe is
It is possible to use the waste heat of an incinerator or melting furnace.

The plastic waste 41 stored in the first heat keeping silo 4 is supplied to the twin screw extruder 1 from the first constant feeder 6 in a constant amount. Hazardous waste 47 stored in the second heat-keeping silo 5 is supplied to the twin-screw extruder 1 by a constant amount from the second quantitative feeder 7. Then, the plastic waste 41 and the hazardous waste 47 are mixed in the twin-screw extruder 1 to form a waste mixture.

Plastic waste 41 and hazardous waste 47
And a waste mixing means for forming a waste mixture by mixing
The crusher 2, the first heat-keeping silo 4, the ash input hopper 3, the second heat-keeping silo 5, the first constant-rate feeder 6, and the second constant-rate feeder 7 The plastic waste 41 and the hazardous waste 47 are mixed together, and the plastic waste 41 from the first quantitative feeder 6 and the hazardous waste 47 from the second quantitative feeder 7 are mixed by a twin-screw extruder. 1 is carried out at the stage of mixing. The melt-kneading means for forming the melt-kneaded material has the twin-screw extruder 1.
The extruding section for extruding the melt-kneaded product to form a molded product is provided with an extrusion die 8. The cooling unit that cools the molded product to obtain the massive molded product 48 includes the cooling water tank 9.

In the waste mixing step of mixing the plastic waste 41 and the hazardous waste 47 to form a waste mixture, the waste plastic from the first quantitative feeder 6 and the waste plastic from the second quantitative feeder 7 are mixed. Is mixed in the twin-screw extruder 1. Before the plastic waste 41 from the first metering device 6 and the hazardous waste 47 from the second metering device 7 are mixed into the twin-screw extruder 1, they are sufficiently mixed. It is also possible to provide a mixing tank having a built-in stirring device. In such a case, the step of mixing the plastic waste 41 from the first fixed-quantity feeder 6 and the hazardous waste 47 from the second fixed-quantity feeder 7 into the mixing tank is the waste mixing step.

In the waste mixing step, the mixing of the plastic waste 41 and the hazardous waste 47 is performed at a weight ratio of 1:
Preferably, it is 0.25 to 1: 4. The content ratio of the hazardous waste 47 to the plastic waste 41 is 0.
When it is smaller than 25, the content ratio of the hazardous waste 47 is small, which is insufficient from the viewpoint of appropriately treating a large amount of hazardous waste. Further, when the content ratio of the hazardous waste 47 to the plastic waste 41 is larger than 4, the content of the plastic waste in the lump is reduced, and as a result, the harmful components in the hazardous waste are reduced. There is a possibility that it may be difficult to firmly enclose in a massive molding.

[0146] The storage site 49 is the bulk molded product 4 according to the present invention.
It is preferable that the equipment is a facility for exclusively storing 8. Calcium salts and hazardous wastes are hardly eluted from the massive molding 48 according to the present invention. Therefore, the wastewater that flows out of the storage site 49 generated by pouring rainwater into the storage site 49 does not substantially contain calcium salts and harmful wastes, and even if the wastewater contains calcium salts and the like. Its content is minimal. Therefore, when the storage site 49 is a facility for storing only the massive molding 48, the deterioration or damage of the storage site 49 is small, and the maintenance and management costs of the storage site 49 can be extremely reduced. It is.

[0147] As shown in FIG.
1 is preferably a plastic waste obtained by separating a vinyl chloride waste 43 and a plastic waste 42 containing no vinyl chloride.

That is, from the plastic waste 41,
The vinyl chloride waste 43 is separated from the plastic waste 42 containing no vinyl chloride, and the plastic waste 42 containing no vinyl chloride waste and the hazardous waste 47 are mixed to form a waste mixture. The melt mixture is melted and kneaded to form a melt-kneaded material, the melt-kneaded material is extruded from an extrusion die, molded to form a molded product, and the molded product is cooled to obtain a massive molded product 48. ,
The massive molded product 48 can be stored in a storage place 49. Hydrogen chloride may be generated from the vinyl chloride waste 43 in the melt-kneading process. Therefore,
By preliminarily separating the vinyl chloride waste 43 and the plastic waste 42 containing no vinyl chloride from the plastic waste 41 and using only the plastic waste 42 containing no vinyl chloride, the massive molded product 48 is extremely safely. Can be obtained, and it is not necessary to consider the measures against hydrogen chloride in the waste treatment system, so that the waste treatment system can be manufactured inexpensively and simply.

On the other hand, the vinyl chloride waste 43 and the plastic waste 42 containing no vinyl chloride are separated from the plastic waste 41, and the vinyl chloride waste 43 and the hazardous waste 47 are mixed. Forming, melting the waste mixture, kneading, forming a melt-kneaded product, extruding the molten kneaded product from an extrusion die, molding to form a molded product, cooling the molded product, A molded product 48 is obtained, and the massive molded product 48 can be stored in the storage area 49. In such a case, the melting temperature in the melt-kneading step is preferably set to 170 to 190 ° C. If the melting temperature is set lower than 170 ° C., it may be difficult to uniformly knead the hazardous waste 47 and the vinyl chloride waste 43 uniformly. If the temperature is set higher than 190 ° C., chlorine chloride is generated as a result of decomposition of vinyl chloride, which is extremely dangerous.

As shown in FIG. 2, the twin-screw extruder 1 has a supply section 14 for feeding and preheating and a melt-kneading section 15 for melting and kneading. The twin-screw extruder 1 melts the waste mixture, and performs kneading with the twin-screw 13, 13 arranged rotatably in the axial direction in the cylinder body to form a melt-kneaded product. This step is a melt-kneading step.

When the waste mixture is melt-kneaded in the twin-screw extruder 1, gas such as steam may be generated.
When a large amount of gas is generated in the twin-screw extruder 1, not only when the pressure in the twin-screw extruder 1 rises but the melt-kneading conditions are different from the assumed conditions, but also It may be damaged. Therefore, the twin-screw extruder 1 is provided with a gas discharger 31 capable of discharging generated gas to an external space.

Next, the melt-kneaded product is extruded from the extrusion die 8 and molded to form a molded product. This step is an extrusion molding step.

The molded product is sufficiently cooled in water in a cooling water tank 9 to obtain a massive molded product 48. This step is a cooling step. As shown in FIG. 1, the cooling water tank 9 is provided with a stirrer 30 near the bottom of the cooling water tank 9 for stirring the cooling water stored in the cooling water tank. The molded product extruded from the extrusion die 8 is in a high temperature state. When the molded product falls into the cooling water tank 9 in such a state, the temperature of the upper portion of the cooling water stored in the cooling water tank 9 rises, thereby cooling the molded product. The cooling effect may be reduced if the cooling water is stationary in the lower part. Therefore, by providing the stirrer 30 near the bottom of the cooling water tank 9, the temperature of the cooling water in the cooling water tank 9 can be kept constant and the cooling effect can be enhanced. After that, the mass 48 is stored in the storage hopper 10.

The mass 48 stored in the storage hopper 10 is stored in a storage area 49. This step is the storage step.

FIG. 2 shows a twin screw extruder 1 and an extrusion die 8.
FIG. 4 is a diagram for explaining in detail the vicinity of. As shown in FIG. 2, the twin-screw extruder 1 includes a plastic waste 41 from a first fixed feeder 6 and a hazardous waste 47 from a second fixed feeder 7. One cylinder body 12 is supplied. The plastic waste 41 and the hazardous waste 47 are mixed by entering between two screws 13, 13 called full flights, which are disposed in the cylinder body 12 so as to be rotatable with respect to each other in the axial direction. A mixture is formed. Then, first, in the supply unit 14,
The waste mixture is fed and preheated. Next, the waste mixture sent from the supply unit 14 is compressed in the melt-kneading unit 15, generates heat by friction with the screw, melts, and is kneaded to form a melt-kneaded material. At this time, in order to adjust the degree of kneading of the melt-kneaded material in the melt-kneading section 15, a gate section 16 capable of adjusting the degree of filling in the melt-kneading section 15 is provided downstream of the melt-kneading section 15. Is provided. The melt-kneaded material melted and kneaded in the melt-kneading section 15 is:
After passing through the gate section 16, it is transported forward by the transport section 17, and the discharge port 1 provided on the side of the cylinder body 12.
Sent to 8. Further, it is fed to the downstream side by a gear pump 20 through a transport section 19 connected to the discharge port 18.
The melt-kneaded material pressure-fed by the gear pump 20 is screened by a screen 21 to remove foreign substances and the like, and then cut by a rotary blade 22 provided on the die surface of the extrusion die 8 using a cut-type pelletizer 23. The pellets are formed into pellets to form a molded article, and thereafter, are transported to the outside by a pellet transporting device (not shown). A motor for rotating the biaxial screws 13 and 13 is indicated by M1, and a motor for rotating the rotary blade 22 is indicated by M2. In addition, the molded product is formed into a pellet by molding with the pelletizer 23. However, the molded product may be formed into an arbitrary shape as well as the pellet shape. For example, from the twin screw extruder 1 to the extrusion die 8
, And may be extruded into a rod shape, cut into short pieces, and put into cooling water to obtain a block-shaped molded product 48. In addition, various granular materials, aggregates, plates, rods,
It is possible to mold it into a molded article.

It is preferable that the block-shaped moldings 48 differ in at least one of mass, volume, and shape. That is, it is preferable that the block 48 does not have a fixed value in at least one of the mass, the volume, and the shape. The massive molding 48 is a substance that is extremely hard to deteriorate, but may deteriorate after a very long time.
In such a case, if the mass of the mass 48 has a certain value, the hazardous waste may be discharged from the mass 48 into the environment at once. Therefore, by setting the mass, volume, or shape of the block 48 to be non-uniform, the deterioration speed of the block 48 can be set differently. In addition, it is possible to avoid a situation in which the hazardous waste is degraded at one time and discharged into the environment.

It is to be noted that various methods can be employed for setting the mass, volume, and shape of the block 48 to be non-uniform. For example, as described above, the pellet is molded by the pelletizer 23. In the process of forming into a pellet, it is only necessary to form the pellet into an uneven shape.

The temperature of the supply section 14 is 50 to 150 ° C.
Is set to If the temperature of the supply unit 14 is lower than 50 ° C., the flexibility of the waste mixture is insufficient, and
This is because it is difficult to carry the waste mixture to the waste mixture 5, and if the temperature of the supply unit 14 is higher than 150 ° C., local heating of the waste mixture may occur.

On the other hand, the temperature of the melt-kneading section 15 is 18
The temperature is set to 0 to 280 ° C. If the temperature of the melt-kneading unit 15 is lower than 180 ° C., the melt-kneading effect becomes insufficient, and if the temperature of the melt-kneading unit 15 is higher than 280 ° C., it is energy inefficient or This is because the resin may be decomposed.

The twin screws 13, 13 in the twin-screw extruder 1 can be any of a non-meshing type, a partially meshing type, and a completely meshing type, but a completely meshing type is particularly preferable. Since the waste treatment system according to the present invention employs the twin-screw extruder 1, that is, the twin-screw, the self-cleaning action for the melt-kneaded material in the two screw flow paths is smaller than that of the single-screw. That is one of the advantages. Further, in the waste treatment system according to the present invention, since the twin screw is adopted, even if it is a non-meshing type twin screw structure, the presence of a stagnant layer is smaller than that of the single screw extruder. Become. In the case of adopting the meshing type twin screw structure, since the flights of the two screws are in contact with each other, the action of scraping the stagnant layer at the bottom of the screw, that is, the self-cleaning action is the shape of the twin screw. It can be further expected according to the rotation direction.

The direction of rotation of the twin screw in the twin screw extruder can be either the same direction rotation or the different direction rotation, but the different direction rotation is particularly preferable. When a co-rotating twin screw is employed, one screw moves along the bottom of the other screw, and a mechanical self-cleaning action is likely to occur. The mechanical self-cleaning action is obtained by a ball screw type or a kneading disk type in the case of a co-rotating twin screw, and by a completely meshing trapezoidal screw in the case of a different direction rotation. When a co-rotating twin screw is used, a single thread (deep groove) and a double thread (intermediate groove)
Alternatively, any of three-start screws (shallow grooves) can be adopted.

In the melt-kneading step, the shear rate applied to the melt-kneaded product is 826 to 2165 (1 / sec.).
It is preferable to set the screw rotation speed as in c). When the shear rate applied to the melt-kneaded material is 826
If it is smaller than (1 / sec), the melt-kneading effect is insufficient, while if it is larger than 2165 (1 / sec), the frictional force becomes large, and as a result, high heat is generated and the resin may be decomposed. Because there is.

The ratio (L / D) of the screw length to the screw diameter in the twin screw extruder is preferably from 24 to 60. If the L / D is less than 24, the melt-kneading effect is not promoted and the melt-kneading of plastic waste and incineration waste tends to be insufficient.
If L / D is larger than 60, excessive energy is consumed for melt-kneading.

In the twin-screw extruder 1, the cylinder body 1 is exposed due to chlorine gas generated by generation of various gases or steam or decomposition of polyvinyl chloride (PVC).
In some cases, the pressure of the melt-kneading unit 15 and the transporting unit 17 in 2 may increase. Therefore, the twin-screw extruder 1 can be provided with a chlorine gas exclusion controller. That is, it is possible to provide an opening in the transfer section 17 of the cylinder body 12 and the like, form an opening box in the opening, and connect a chlorine gas elimination line to the opening box. A pressure sensor is provided inside the opening box, and the pressure in the cylinder 12 is detected by a pressure gauge connected to the pressure sensor. Then, various gases are removed from the gas removal line based on the pressure value detected by the pressure gauge.

The cylinder body 12 may be provided with a temperature detecting section capable of detecting the temperature, a temperature increasing section capable of increasing the temperature, and a cooling section capable of decreasing the temperature. For example, the cylinder body 12 is divided into a plurality of temperature control sections, and a heater is provided on an outer surface of each section,
A temperature detecting unit such as a thermocouple is provided on the upper or lower side of the cylinder main body 12, and the temperature can be set to a temperature at which the melt-kneaded material supplied into the cylinder main body 12 does not thermally decompose. As the cooling unit, the cylinder body 12 of the twin-screw extruder 1 is formed into a jacket, and water or a coolant having an appropriate temperature is circulated through the jacket of each section, so that an appropriate cooling effect can be provided. .

In the waste mixing means, the mixing of the plastic waste 41 and the hazardous waste 47 is performed in a weight ratio of 1: 1:
Preferably, it is 0.25 to 1: 4. The content ratio of the hazardous waste 47 to the plastic waste 41 is 0.
When it is smaller than 25, it is insufficient from the viewpoint of properly treating a large amount of hazardous waste, and the running cost for treating the hazardous waste increases. Further, when the content ratio of the hazardous waste 47 to the plastic waste 41 is larger than 4, it may be difficult to encapsulate the hazardous components in the hazardous waste in the bulk molding for a long period of time. There is.

By performing the waste disposal method according to the present invention, it is possible to obtain the massive molding 48. The mass 48 is mixed with a plastic waste 41 and a hazardous waste 47 containing at least one of incineration ash, soot, sludge and contaminated soil, melt-kneaded by the twin-screw extruder 1, and extruded. It is a massive molded product 48 obtained by extruding from a die for use, molding and then cooling.

From the block 48, the hazardous waste 4
Hazardous waste such as heavy metal ions contained in 7 tends to be extremely difficult to flow out. The reason is that the hazardous waste such as heavy metal ions contained in the hazardous waste 47 is sealed in the bulk molding 48, and that the bulk molding 48
Is very strong and hard to crack.

As described above, the block-shaped molded product 48 firmly seals the hazardous waste 47, and stabilizes the hazardous waste contained therein physically and chemically. Also,
This massive molding 48 has extremely strong performance against destruction by pressure and impact and deterioration by soil bacteria, ultraviolet rays, acid rain and the like. Indeed, the mass 48 is about 10-5
Deterioration gradually over a long period of about 0 years, peeling, cracking, cracks, etc. may occur on the surface of the massive molded product, and the hazardous waste enclosed inside may flow out from the cracks, etc. generated on the surface Although there may be, when compared with the case where the hazardous waste 47 is cemented, the phenomenon of collapse, cracking, and weathering in a short period of time after a certain period of time, like the case of cementing with the cement, Hazardous waste does not flow into the natural environment at once because it is unlikely. Even if the bulk molded product 48 according to the present invention is deteriorated, the deterioration rate of each molded product is different due to the difference in the material mixing ratio, strength, shape, size, etc. of the molded product, so that the harmful waste is external. Even if spilled, it is spread over a long period of time and is contained in a very small amount, so it is considered that the possibility of adverse effects on people's lives and natural environment is extremely low.

When the compressive strength of the block 48 was measured, it was 600 to 1500 kgf / cm ² , which was higher than the compressive strength of natural stone. When the bulk molded product 48 according to the present invention is crushed into small pieces with a hammer, it was too hard to require considerable time and force.

Further, even if the massive molding 48 according to the present invention was left in water for one year, the heavy metals in the hazardous waste 47 hardly flowed into the water. Further, the Ph of the water after standing for one year remained neutral without any change. Furthermore, even when the massive molded product 48 according to the present invention is left in salt water for one year, or in acidic water having a pH of about 4 for one year, almost no outflow of heavy metals in the hazardous waste 47 into water occurs. Did not.

[0172] The Environment Agency Notification No. 13 test as a dissolution test was conducted in such a manner that various hazardous wastes brought into the disposal site or solidified harmful wastes with cement or the like were broken or cracked by some pressure or impact. It is mandatory to crush the solidified material to 5 mm or less and measure the elution value of heavy metals and the like from fragments and powders of 5 mm or less, assuming that most of them will be weathered or deteriorated for many years. ing. The mass molded product 48 according to the present invention was first notified by the Environment Agency.
Even in the case of the No. 3 test, the outflow of hazardous waste could be suppressed to a very small amount, and was within the legally required landfill standard value.

The Environment Agency Notification No. 13 test method means that a sample is pulverized to a particle size of 5 mm or less, to which 10 times pure water is added to obtain a solid-liquid ratio of 10 and shaken for 6 hours. This is a test method for measuring the concentration of a substance in a solution obtained by filtration.

The dust discharged from the incinerator was kneaded with pure water and dried and solidified, and the test was conducted with the Environment Agency Notification No. 13 to measure the elution amount of the lead component.

On the other hand, polyethylene terephthalate (PE)
T) 100 g (85.5% by mass) of waste and dust (14.5% by mass) discharged from the incinerator are melted by the twin-screw extruder 1 using the waste treatment method according to the present invention. A mass 48 was obtained by kneading. This block 48
The test was conducted with the Environment Agency Notification No. 13 to measure the elution amount of the lead component.

Dust discharged from the incinerator was taken as a comparative example, while the lump 48 according to the present invention was taken as the present invention, and the test results are shown in Table 1 below.

[0177]

[Table 1]

In the case of the comparative example, the amount of lead eluted was 48 ppm, and the amount of lead eluted showed a high value, whereas in the case of the present invention, the amount of lead eluted from the block 48 was 0.01 ppm.
Below, the amount of lead eluted showed a considerably low value. Therefore, in the bulk molded article 48 in the case of the present invention, the lead elution amount reduction rate is 99.98% or more as compared with the comparative example. Since the elution amount is 0.01 ppm or less in a severe elution test performed on a molded product having a particle size of 5 mm or less, the elution amount of a bulk molded product having a small surface area is considered to be almost equal to zero. Even if the bulk molded product 48 according to the present invention is stored, it is considered that it is sufficiently safe in terms of environmental protection. As described above, the lumpy molded product 48 obtained by this system is particularly capable of dissolving harmful waste even if it becomes particulate because the plastic is dense and dust and the like are evenly dispersed. And it is highly likely that it will be the same as the natural environment or less than the environmental standard value.

[0179] Therefore, in addition to storage, the lump-shaped molded article formed by this system can be left in the natural world 57 or can be used as a civil engineering work material 56. The massive molded product 48 stored in the storage site 49 can be used as civil engineering work material 56. Concretely, the civil engineering materials 56 include roadbed materials for road construction, subgrade materials for elevated roads, soundproofing materials for highways, rooftop waterproofing materials for public buildings, materials for reclamation works, and materials for waste disposal site construction. Materials,
It can be used for construction materials for marine disposal sites, block materials for seawalls, construction materials for marine airports, etc.

As described above, the massive molded product 48 according to the present invention is used.
Has strong strength, and has been devised so that any shape and size can be intentionally changed in the manufacturing process so that it can be used as a substitute for crushed stone and gravel.Therefore, roadbed materials, backfill materials, asphalt -It can be widely used in various places as concrete aggregate.

It is preferable that the average particle size of the bulk molded product is 5 mm or less. 5 mm average particle size
By doing the following, the bulk specific gravity of the massive molded product can be reduced, and the filling rate can be improved when storing the massive molded product. Further, by setting the average particle size of the massive molded product to 5 mm or less, kneading and dispersion of the massive molded product can be improved. In addition, by setting the average particle size of the massive molded product to 5 mm or less, the handleability, transportability, and workability of the massive molded product can be improved. Furthermore, by setting the average particle size of the massive molded product to 5 mm or less, the drop strength of the massive molded product can be improved. In addition, by setting the average particle size of the block-shaped product to 5 mm or less, it is easy to process the block-shaped product so as not to have a fractured surface. Furthermore, when the average particle size of the block-shaped product is 5 mm or less, when the block-shaped product is put into the melting furnace, the block-shaped product is instantaneously and continuously instantaneously and pneumatically fed from the side inlet of the melting furnace. Can be entered. Further, when the average particle size of the massive molded product is 5 mm or less, when the massive molded product is put into the melting furnace, it is easy to gasify instantaneously in the lower part of the melting furnace. In addition, the fact that the average particle size of the bulk molded product is 5 mm or less means that J
It means passing through a sieve made of a 5 mm mesh defined by the IS standard. In addition, it is more preferable that the average particle diameter of the block-shaped molded product is 3 mm or more and 5 mm or less.

Further, it is preferable that a surface treatment is performed on the surface of the bulk molded article so that the hazardous waste does not flow out. As the surface treatment, the surface of the massive molded product can be treated using an aqueous solution of aluminum sulfate. In other words, by immersing the lump in the aluminum sulfate aqueous solution, even if the lump is attached to the surface of the lump, the hazardous waste can be chemically transformed into an insoluble compound. .

Further, by reheating the massive molded product as a surface treatment, the plastic resin can be dissolved again, and the hazardous waste can be covered with the completely melted plastic resin. In addition, reheating is performed for the mass-formed product in
It is preferred to heat at 00 ° C for 4-5 minutes.

It is preferable that the lump-shaped molded product contains an inorganic powdery or granular material that makes the harmful waste hardly soluble.
The inorganic particles are inorganic particles containing cement, silica, alumina, magnesium, calcium, iron and the like. In addition, the inorganic powdery or granular material is 300
Those which do not decompose, dissolve or corrode even at a temperature of about ° C are preferred. The inorganic powdery particulate matter is preferably contained at 5 to 30% by mass, more preferably 5 to 20% by mass, based on the hazardous waste.

It is preferable that the bulk molding contains an oil component. Thereby, the water repellency of the massive molded product can be improved. Since the water repellency of the massive molded product can be improved, even if rainwater or the like hits the massive molded product, the hazardous waste does not dissolve in the water and flows out into the environment. As the oil component, those having water repellency and heat resistance are suitable, and specifically, silicone oil or the like can be used. Silicon oil is preferably used as a diluent of about 3 to 5% by mass diluted with water.

Plastic waste 41 and hazardous waste 47
Is preferably 1: 0.25 to 1: 4 by weight. When the content ratio of the hazardous waste 47 to the plastic waste 41 is smaller than 0.25,
The running cost for treating hazardous waste is increased. Further, when the content ratio of the hazardous waste 47 to the plastic waste 41 is larger than 4, it may be difficult to encapsulate the hazardous component for a long period of time.

In the waste disposal method according to the present invention, industrial waste or general waste generated in an administrative area is incinerated in an incinerator 53 existing in the administrative area, or present in the administrative area. A waste mixing step of mixing the incineration waste generated by melting in the melting furnace 54 and the plastic waste 41 generated in the administrative area to form a waste mixture; and melting the waste mixture. A melt-kneading step of kneading to form a melt-kneaded product, an extrusion molding step of extruding the melt-kneaded product from an extrusion die and molding to form a molded product, and cooling the molded product to form a massive molded product 48 A cooling step for obtaining
Is used as a civil engineering work material 56 in a civil engineering work in the administrative area, thereby reusing the incineration waste and the plastic waste.

The incineration waste generated in the administrative area and the plastic waste 41 are mixed, melt-kneaded, extruded, and then cooled to form a lump-shaped molded article 48, which is used for the civil engineering in the administrative area. Civil engineering work materials 5 in the construction business
By reusing as 6, self-contained waste disposal at the administrative district level becomes possible. That is, the plastic waste 41, which is the majority of the waste 40 collected in the administrative area, is separated, taken out, and crushed. The incinerated ash 45 and soot and dust 44 produced by burning the remaining combustible waste and the like are mixed with the plastic waste 41, melt-kneaded, extruded and then cooled to form a massive molded product 48.
By using 8 as a roadbed material or backfill material for road construction instead of quarrying or the like, an organization having control over the administrative area can reduce the disposal cost of the waste 40 accordingly. An organization that has control over an administrative area is an organization that covers a part of the country and gives residents living in that area autonomous control within the scope of the law. It is an organization. In addition, the administrative area is a range with a domestic division governed by the above-mentioned group having the controlling right, and corresponds to, for example, a prefecture or a municipal government. Further, the waste 40 includes industrial waste and general waste generated in the administrative area, and further includes plastic waste generated in the administrative area.

The plastic waste 41 and the incineration waste are mixed, melt-kneaded, extruded and then cooled to form a lump 48, which is reused as a civil engineering material 56 in a civil engineering business. By doing so, there is almost no need to bury the plastic waste 41 and the incineration waste in a final disposal site or the like, so that the life of such a final disposal site can be extended.

Further, according to the waste disposal method of the present invention, industrial waste or general waste generated in an administrative area is
Incineration waste generated by incineration in the incinerator 53 or melting in the melting furnace 54 existing in the administrative area and plastic waste 41 generated in the administrative area are mixed to generate waste. A waste mixing step of forming a mixture, a melt kneading step of performing a melt kneading on the waste mixture to form a melt kneaded product, and extruding the melt kneaded product from an extrusion die to form a molded product. Extrusion molding step, and cooling the molded product to form
And the use of the mass 48 as fuel for the melting furnace 54 present in the administrative area to provide the incineration waste and the plastic waste 41.
And a reuse step of reusing.

When the block 48 is used as a fuel for the melting furnace 54, the incineration ash 4 contained in the block 48 may be used.
5. About 95% (weight ratio) of the soot and dust 44 is converted into molten slag in the melting process. Then, the molten slag is cooled by a cooling means such as water cooling or air cooling to be a cooled solidified product. The harmful substances such as the incineration ash 45 and the dust 44 are enclosed in the solidified cooling material, so that the harmful substances do not flow out of the environment. Therefore, the massive molded product 48 can be used as fuel for the melting furnace 54 to be converted into molten slag, and the molten slag can be effectively used as a civil engineering construction material 56.

Further, the waste disposal method according to the present invention is a method of mixing a hazardous waste generated in an administrative area with a plastic waste 41 generated in the administrative area to form a waste mixture. A mixing step, a melt-kneading step of melt-kneading the waste mixture to form a melt-kneaded product, and an extrusion molding step of extruding the melt-kneaded product from an extrusion die and forming a molded product by molding. The method includes a cooling step of cooling the molded article to obtain a massive molded article 48, and a storing step of accumulating the massive molded article 48 in the administrative area.

In the concept of discarding or discarding incinerated ash, dust, sludge, contaminated soil, and the like, since the lands that can be effectively used are limited, there will be a shortage of landfills for garbage and harmful substances in the near future, and Can also be a serious environmental concern. Further, in recent years, the amount of plastic waste generated has increased, and it is a serious problem to dispose of the plastic waste 41. The conventional idea of discarding the plastic waste 41 is, as described above, insufficient for the final disposal site. As a result, the country as a whole may become a serious environmental conservation problem. Especially plastic waste 4
Among them, the amount of plastic bottle (polyethylene terephthalate) waste tends to increase.

Therefore, the idea is changed from the conventional concept of disposal to the concept of storage. However, it is difficult to effectively use all of the municipal garbage, which is estimated to generate more than 50 million tons per year. Hazardous waste 47 such as ash 45 and dust 44 and plastic waste 41 are mixed, melt-kneaded, extruded, and cooled to form a lump 48, which is temporarily stored. The stored bulk molding 48 can be used in public works and the like.

In the melt-kneading step, the waste mixture is melted by a twin-screw extruder 1 having a supply section for feeding and extra heat and a melt-kneading section for melting and kneading, and the melt is kneaded into a cylinder body. The kneading process is preferably a kneading process in which kneading is performed with a biaxial screw arranged so as to be mutually rotatable in the directions to form a melt-kneaded product.

Hazardous waste 47 and plastic waste 41
, Melt-kneaded with a twin-screw extruder, extruded, and then cooled to form a block 48, which has a compressive strength of 6%.
It is 100-1500 kgf / cm ² , more tough than natural stone, and can withstand high pressure and impact. For this reason, the massive molded article 48 can be used as a civil engineering work material 56 in a civil engineering work in an administrative area. Specifically, a roadbed material for road construction, a roadbed material for an elevated road, an expressway It can be used for soundproofing materials, rooftop waterproofing materials for public buildings, materials for reclamation work, materials for construction of waste disposal sites, materials for construction of marine disposal sites, block materials for seawalls, materials for construction of marine airports, etc. . Here, the offshore airport construction materials refer to construction materials used for facilities artificially constructed on the sea such as airport construction. Also,
Even if the massive molded product is broken, it is only divided into several pieces, and is not divided into small pieces as when concrete is broken. Therefore, even if the massive molded product is broken, only a relatively small amount of hazardous waste elutes from the damaged surface, and does not cause water pollution or groundwater pollution exceeding environmental standards.

Examples of the plastic waste 41 include polyethylene, polypropylene, polystyrene, AS resin, ABS resin, vinyl chloride resin, methacrylic resin, polyethylene terephthalate, polyvinylidene chloride, ethylene vinyl alcohol copolymer, ACS resin, ASA resin
It is possible to use general-purpose plastic waste such as resin and AES resin.

Most of the waste generated in the administrative area is the plastic waste 41. For example, about 30 to 50% by volume (7 to 12% by weight) of the plastic waste 41 is included in the municipal waste. Is mixed. In the waste disposal method according to the present invention, the plastic waste 41 is not incinerated, but is mixed with the hazardous waste 47, melt-kneaded, extruded, and then cooled to form a massive molded product 48. Since it is reused as the civil engineering work material 56 in the civil engineering work, the amount of carbon dioxide generated by incineration can be significantly reduced. Therefore, it is possible to further contribute to environmental conservation in each administrative area.

Further, in the waste disposal method according to the present invention, the incineration waste generated in the administrative area and the plastic waste are mixed, melt-kneaded, extruded and then cooled to form the mass 48. Need to transport incinerated waste and plastic waste 41 generated in the administrative area to a distant final disposal site by making it and reusing it as civil engineering material 56 in the civil engineering work in the administrative area. There is no. Therefore, there is no need to use a large amount of transportation energy for intrinsically invaluable waste such as incineration waste and plastic waste 41.

The metal component-containing waste and the molten plastic waste are kneaded, cooled and solidified to form a lump-shaped molded product. After storing the lump-shaped molded product, the metal component is recovered from the lump-shaped molded product. can do. Here, storing the massive molded product means storing the massive molded product for a long period of time with the intention of taking out and effectively utilizing the metal component contained in the massive molded product in the future.

The wastes include hazardous wastes and non-hazardous wastes that have little or no effect on living organisms or the environment. More specifically,
The waste contains a harmful metal component and a non-hazardous metal component that has little or no effect on living organisms or the environment.

[0202] Recovering metal components contained from wastes such as incinerated ash and dust is expensive at present and has not been commercialized. However,
The reserves of minable metals are limited, and it is necessary to implement a method for recovering metal components from waste in the future, especially for metals with low reserves.

Therefore, in the present invention, the waste containing the metal component is temporarily stored in the form of a lump, and the contained metal component is recovered from the lump as needed. Since the contained metal component is encapsulated in the bulk molding, even if the metal component is a harmful metal component, it does not affect the natural world.

[0204] Further, in this way, when the bulk molded product is stored in the disposal site, the space of the disposal site is increased by the amount of the bulk molded product from which the contained metal component has been recovered. Can be reused.

The above-mentioned stockpiling is not limited to the above-mentioned disposal site,
This can be done at a storage place provided for the purpose of stockpiling. In particular, when stockpiling waste consisting only of non-hazardous waste, it is possible to pile up.

[0206] When a waste that requires collection of a metal component and a waste that does not require collection of a metal component are disposed in the same disposal site, the collection of the required metal component requires another waste. It is necessary to separate the sediment from the soil and soil used for earth covering, and it is necessary to transport the separated material to a smelter located in a remote place. Therefore, when stockpiling, it is preferable to stock only wastes that require recovery of metal components.

Hazardous waste includes incinerated ash discharged from an incinerator or melting furnace, incinerated waste such as dust, toxic waste such as sludge, contaminated soil, sludge, and the like. ), Coal ash, shredder dust, waste gypsum boats and the like. In particular, incinerated ash or dust generated by incinerating industrial waste or general waste in incinerators, and dust generated from melting furnaces may contain relatively large amounts of zinc and lead components. is there. Therefore, if the dust and incineration ash generated from the incinerator or melting furnace and the molten plastic waste are kneaded and cooled and solidified to form a lump-shaped molded article, the lump-shaped lump was stored very safely for a long time. Thereafter, a zinc component and a lead component can be recovered from the bulk molded product at a high recovery rate.

Aluminum slag (aluminum dross) is an impurity generated on the surface of a molten metal when aluminum ingots and scraps are melted in the process of manufacturing an aluminum product. The amount of aluminum slag (aluminum dross) depends on the melting method and the type of raw material.
Degree occurs. Since alumidroth cannot be used as it is, it is usually removed from the melting furnace, but contains a large amount of reusable metal aluminum components, about 60%. Almidros are produced in Japan at about 350,000 tons annually, and in Japan, where most of the aluminum ingots are relied on overseas, the establishment of technology that can efficiently recover metal aluminum has become an important issue. However, in a conventional processing method such as a burner-type rotary furnace, the recovery rate of the aluminum component is limited to 40 to 60% because the metal aluminum component is reduced by an oxidation reaction during the processing.
In addition, most of the 100,000 tons of ash generated annually after the recovery of aluminum components is disposed of in landfills in managed landfills as industrial waste. In addition to rising disposal costs, nitrides in the residual ash react with water to produce ammonia gas with an irritating odor. I have. So, with aluminum dross,
By kneading the molten plastic waste and cooling and solidifying it to form a lump, it is extremely safe to store the lump over a long period of time and then recover the aluminum component from the lump at a high recovery rate You can do it. That is, according to this method, the aluminum component can be recovered at a high recovery rate while solving the problem of securing the disposal site.

Coal ash is a type of incineration ash generated from thermal power plants, and reaches 600,000 tons annually. The main components of the coal ash are silica and alumina, and the alumina contains about 70% of the coal ash. Similarly, if this coal ash is kneaded with the coal ash and the molten plastic waste, and cooled and solidified to form a lump-shaped molded article, it is extremely safe to store the lump-shaped molded article for a long time. The aluminum component can be recovered from the bulk molded product at a high recovery rate. According to this method, the aluminum component can be recovered at a high recovery rate while solving the problem of securing the disposal site.

[0210] Shredder dust broadly refers to waste obtained by cutting industrial waste with a shredder. For example, shredder dust for automobiles contains copper as a metal component. Conventionally, shredder dust of this vehicle has not been recycled and has been disposed of in landfills. Similarly, this shredder dust is similarly aggregated by kneading the shredder dust with molten plastic waste and cooling and solidifying it. In the case of a molded product, the copper component can be recovered from the massive molded product at a high recovery rate after stockpiling the massive molded product for a very long time. According to this method, the copper component can be recovered at a high recovery rate while solving the problem of securing the disposal site.

[0211] Waste gypsum board is waste gypsum board. Gypsum board is a construction material that is light and easy to process, with a slightly thick paper stuck on both sides of a thin gypsum board. Gypsum board has excellent heat insulation, sound insulation, and fire protection properties, and is widely used as a representative of semi-combustible materials. Waste gypsum boards contain arsenic, cadmium and the like, and in recent years, with the increase of waste gypsum boards accompanying the dismantling of buildings, the treatment method has become a major environmental problem. However, as for the waste gypsum board, similarly, if the waste gypsum board and the molten plastic waste are kneaded and cooled and solidified to form a massive molded product,
After stockpiling massive moldings very safely for a long time,
The arsenic component and the cadmium component can be recovered from the bulk molded product at a high recovery rate. According to this method, the arsenic component and the cadmium component can be recovered at a high recovery rate while solving the problem of securing the disposal site.

FIG. 5 is a flow chart of a means for recovering a metal component from a stored bulk molding. Here, the case where dust and incineration ash generated from incinerators and melting furnaces and molten plastic waste are kneaded, and a zinc component and a lead component are collected from a block-shaped molded product that has been cooled and solidified will be described as an example. do.

[0213] The massive molding 48 is heated in a heating furnace (pyrolysis furnace) 70.
, The air is cut off and heated to melt and decompose the plastic component of the block-shaped molded product 48 to obtain a decomposed gas 72 and a decomposed oil 73. The heating in the heating furnace 70 with the air cut off is preferably performed at about 450 to 550 ° C.

At the bottom of the heating furnace 70, a residue (Tiacol) 74 and an ash (incinerated fly ash or molten fly ash) 75 remain. The residue (Tiacol) 74 and the ash (incinerated fly ash or molten fly ash) 75 are taken out, and the mixture thereof is heated in the melting furnace 54 by high-temperature combustion gas. The heating in the melting furnace is performed at 1300 to 1500 ° C.
It is possible to do to an extent. As a result of heating the mixture with a high-temperature combustion gas, a metal oxide 78 such as zinc oxide ZnO76 or lead oxide PbO77 is obtained. This is collected by a dust collector and recovered as a powdery metal oxide 78. On the other hand, the molten slag 58 is obtained by throwing incinerated fly ash or molten fly ash melted by high temperature at the bottom of the melting furnace 54 into water.

Next, zinc oxide ZnO76 and lead oxide PbO
In a reduction furnace 71, coke 79 is added, and heated and reduced to obtain metal zinc powder 80 and metal lead 81. The heating in the reduction furnace 71 is 1
It can be performed at 200 to 1300 ° C.

According to the above-described method, the incinerated ash having a metal component content of 5% and the waste plastic are in a weight ratio of 50: 5.
When 1000 kg of a lump-shaped molded product in the case of 0 is treated, about 25 kg of metallic zinc or metallic lead can be obtained.

In the recovery process of metallic zinc and metallic lead, a decomposition gas 72 obtained by pyrolysis of waste plastic in the heating furnace 70 is used as a heat source of the heating furnace 70 itself and a heat source of the melting furnace 54 and the reduction furnace 71. By doing so, most of the heat energy required for operating the metal recovery device can be covered, and the operation can be performed extremely economically. Further, the cracked oil 73 obtained by the thermal decomposition of the waste plastic can be used as a fuel such as gasoline, light oil, and kerosene by refining.

It should be understood that the embodiments disclosed this time are illustrative in all aspects and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

[0219]

By using the waste treatment method according to the present invention or implementing the waste treatment system according to the present invention, incineration wastes discharged from incinerators, melting furnaces, and general households are discharged. Both plastic waste and plastic waste were properly treated so as not to flow into the living environment, and the incinerated waste and plastic waste could be used effectively.

[0220] Further, the massive molded product obtained by using the waste disposal method according to the present invention has a strong hardness,
Hazardous waste such as heavy metals is difficult to leak to the outside,
It can be used for civil engineering materials such as roadbed materials, and has excellent environmental protection effects.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a waste treatment system according to the present invention.

FIG. 2 is a schematic diagram illustrating a twin-screw extruder used in a waste treatment system according to the present invention.

FIG. 3 is a schematic diagram illustrating a waste disposal method according to the present invention.

FIG. 4 is a schematic diagram illustrating a conventional waste disposal method.

FIG. 5 is a diagram illustrating a flowchart for collecting a metal component.

[Explanation of symbols]

1 twin screw extruder, 2 crusher, 3 ash input hopper, 4
1st heat keeping silo, 5 second heat keeping silo, 6 1st constant feeder, 7 2nd constant feeder, 8 extrusion die, 9 cooling water tank, 10 storage hopper, 12 cylinder body, 13 screw, 14 supply section, 15 Melt kneading section, 16 Gate section, 17 Transport section, 18 Discharge port, 1
9 conveyor, 20 gear pump, 21 screen, 2
2 rotary blade, 23 pelletizer, 24 first circulating air heater, 25 second circulating air heater, 26 first blower, 27 second blower, 28 first cyclone, 29
2nd cyclone, 30 stirrer, 31 gas exhauster, 3
2 First Venturi, 33 Second Venturi, 34
First pressure regulating valve, 35 Second pressure regulating valve, 40 waste, 41 plastic waste, 42 vinyl chloride-free plastic waste, 43 vinyl chloride waste,
44 soot and dust, 45 incinerators, 46 other harmful substances,
47 Hazardous waste, 48 Bulk molding, 49 Reservoir,
50 temporary storage site, 51 storage site, 52 disposal site, 53 incinerator, 54 melting furnace, 55 melting furnace fuel, 56 civil engineering work materials, 57 leaving, 58 molten slag, 70 heating furnace,
71 reduction furnace, 72 cracked gas, 73 cracked oil, 74
Thiacol, 75 ash, 76 ZnO, 77 PbO,
78 metal oxide, 79 coke, 80 zinc powder, 8
1 Metal lead.

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) B09C 1/02 C10L 5/46 1/06 5/48 1/08 B29K 23:00 B29B 17/00 25:00 C02F 11 / 00 27:00 C10L 5/46 29:00 5/48 33:00 // B29K 23:00 67:00 25:00 B09B 3/00 303E 27:00 ZAB 29:00 303L 33:00 303P 67:00 304P 304G 304K F-term (reference) 4D004 AA07 AA36 AA37 AA41 AB03 AB05 AB07 BA02 BA03 BB10 CA07 CA14 CA15 CA22 CA27 CA29 CA32 CA37 CA42 CA45 CB12 CB16 CB26 CB42 CB43 CB44 CB47 CC11 CC13 CC15 DA01 DA02 DA03 DA06 DA06 DA03 DA01 DA02 DA03 BK09 BK10 CB01 CC03 CC04 DA03 DA08 DA12 DA19 DA22 DA35 DA66 DB40 EB06 EB11 EB20 4F301 AA13 AA14 AA15 AA17 AA19 AA25 BC26 BC33 BC38 BD09 BD22 BD23 BD29 BD42 BD43 BD48 BF08 BF16 BF31 BG15 A17 BG15 A17 BG16 A57 BG16 BB01 BB06 CA03 CB01

Claims (34)

[Claims] 1. A kneading step of kneading harmful waste and a molten plastic waste, a forming step of solidifying by cooling and solidifying, and a storing step of storing the bulk forming substance in a storage area And a waste disposal method comprising: 2. The waste treatment method according to claim 1, wherein the forming step is to form a block-shaped product by reducing the average particle size to 5 mm or less while gradually cooling. 3. After the molding step,
3. The waste treatment method according to claim 2, further comprising a surface treatment step of performing a surface treatment so that the hazardous waste does not flow out. 4. The method according to claim 1, wherein in the kneading step, an inorganic powdery substance that makes the harmful waste hardly soluble is mixed.
4. The waste disposal method according to any one of 3. 5. The waste treatment method according to claim 1, wherein an oil component is mixed in the kneading step. 6. The storage site according to claim 1, wherein said storage site is a disposal site.
The waste disposal method according to any one of the above. 7. The hazardous waste is incinerated ash, soot and dust,
The waste disposal method according to any one of claims 1 to 6, wherein the method comprises at least one of sludge and contaminated soil. 8. The hazardous waste contains at least one of dust and incinerated ash.
7. The waste disposal method according to any one of 6. 9. A waste mixing step of mixing a plastic waste and a hazardous waste containing at least one of incineration ash, dust, sludge and contaminated soil to form a waste mixture; Melting and kneading to form a melt-kneaded product; a melt-kneading process for extruding the melt-kneaded product from an extrusion die to form a molded product by molding; and cooling the molded product to form a block. A waste treatment method comprising: a cooling step of obtaining a molded article; and a storage step of storing the massive molded article in a storage area. 10. A plastic waste is pneumatically transported with heated air from a crusher for crushing the plastic waste to a first thermal insulation silo for storing the plastic waste in a heated state, and the incineration ash, soot and dust, Hazardous waste containing at least one of sludge and contaminated soil is pneumatically transported by heated air from an ash input hopper into which the hazardous waste is charged to a second thermal insulation silo that stores the hazardous waste in a heated state. A transporting step, a waste mixing step of mixing the plastic waste stored in the first thermal silo with the hazardous waste stored in the second thermal silo to form a waste mixture, and the waste Melt-kneading step of melting and kneading the material mixture to form a melt-kneaded material; extruding the melt-kneaded material from an extrusion die, molding and molding A waste disposal method comprising: an extrusion molding step of forming an object; a cooling step of cooling the molded article to obtain a lump molded article; and a storage step of storing the lump molded article in a storage place. 11. A waste treatment method in which a hazardous waste and a molten plastic waste are kneaded, cooled and solidified to form a massive molded product, and the massive molded product is used as fuel for a melting furnace. 12. The waste disposal method according to claim 1, wherein the mass is stored in a storage area, and then the mass is used as a fuel for a melting furnace. 13. The melt-kneading step is a twin-screw extruder having a supply section for feeding and preheating and a melt-kneading section for melting and kneading, wherein the waste mixture is melted, The waste treatment method according to claim 9 or 10, wherein a kneading process is carried out by kneading with a biaxial screw arranged rotatably to form a melt-kneaded product. 14. The plastic waste is polyethylene, polypropylene, polystyrene, AS resin, AB
S resin, vinyl chloride resin, methacrylic resin, polyethylene terephthalate, polyvinylidene chloride, ethylene vinyl alcohol copolymer, ACS resin, ASA resin, A
The waste disposal method according to any one of claims 1 to 13, which is a general-purpose plastic waste containing at least one of ES resins. 15. The plastic waste according to claim 1, wherein said plastic waste is a plastic waste obtained by separating vinyl chloride waste and plastic waste containing no vinyl chloride.
4. The waste disposal method according to any one of 3. 16. The waste disposal method according to claim 1, wherein the weight ratio of the plastic waste and the hazardous waste is 1: 0.25 to 1: 4. 17. The waste disposal method according to claim 1, wherein the storage site stores only the bulk molded product. 18. The waste disposal method according to claim 1, wherein the bulk molded article differs in at least one of mass, volume, and shape. 19. A plastic waste and a hazardous waste containing at least one of incinerated ash, dust, sludge and contaminated soil are mixed, melt-kneaded, extruded from an extrusion die, molded, and cooled. Lumped molded product obtained by letting it. 20. The massive molded product according to claim 19, wherein the average particle size of the massive molded product is 5 mm or less. 21. The massive molding according to claim 19, wherein the surface of the massive molding is subjected to a surface treatment so that the hazardous waste does not flow out. 22. The mass-formed product contains an inorganic powdery particulate material that makes the hazardous waste hardly soluble.
21. The massive molded article according to any one of 21. 23. The massive molded article according to claim 19, wherein the massive molded article contains an oil component. 24. The massive molded product according to claim 19, wherein the weight ratio of the plastic waste and the hazardous waste is 1: 0.25 to 1: 4. 25. A waste mixing means for mixing a plastic waste and a hazardous waste containing at least one of incineration ash, dust, sludge and contaminated soil to form a waste mixture; A melt kneading means for melting and kneading to form a melt kneaded product; an extrusion molding means for extruding the melt kneaded material from an extrusion die and molding to form a molded product; and cooling and cooling the molded product. A waste treatment system having a cooling means for obtaining a molded product. 26. Pneumatic transport of plastic waste from a crusher for crushing the plastic waste to a first thermal insulation silo for storing the plastic waste in a heated state, while incinerating ash, soot and dust, Hazardous waste containing at least one of sludge and contaminated soil is pneumatically transported by heated air from an ash input hopper into which the hazardous waste is charged to a second thermal insulation silo that stores the hazardous waste in a heated state. Transportation means; a waste mixing means for mixing the plastic waste stored in the first heat-keeping silo with the hazardous waste stored in the second heat-keeping silo to form a waste mixture; Melt-kneading means for melting and kneading the material mixture to form a melt-kneaded material, and extruding the melt-kneaded material from an extrusion die, molding and molding A waste treatment system comprising: extrusion molding means for forming an object; and cooling means for cooling the molded article to obtain a lump molded article. 27. A first canned silo for storing the plastic waste, a first steam pipe wound around an outer surface of the first canned body and through which steam flows. A second heat retaining silo includes a second can body storing the hazardous waste, and a second steam pipe wound around an outer surface of the second can body and through which steam flows. 27. The waste treatment system according to claim 26. 28. A twin-screw extruder in which said melt-kneading means has a supply section for feeding and remaining heat and a melt-kneading section for melting and kneading, and melts said waste mixture in an axial direction in a cylinder body. 28. The waste treatment system according to claim 25, wherein the waste treatment system is a melt-kneading means for forming a melt-kneaded material by kneading with a biaxial screw arranged rotatably to each other. 29. The plastic waste is polyethylene, polypropylene, polystyrene, AS resin, AB
S resin, vinyl chloride resin, methacrylic resin, polyethylene terephthalate, polyvinylidene chloride, ethylene vinyl alcohol copolymer, ACS resin, ASA resin, A
The waste treatment system according to any one of claims 25 to 28, wherein the waste treatment system is general-purpose plastic waste containing at least one of ES resins. 30. The waste mixing means according to claim 25, wherein the mixing ratio of the plastic waste and the hazardous waste is 1: 0.25 to 1: 4 by weight. Waste treatment system. 31. The method according to claim 25, further comprising storage means for storing the lump-shaped molded product in a storage place after obtaining the lump-shaped molded product.
30. The waste treatment system according to any one of 30. 32. A hazardous waste including at least one of incineration ash, dust, sludge or contaminated soil generated in an administrative area, and a plastic waste generated in the administrative area, and the waste is mixed. A waste mixing step of forming a mixture, melting the waste mixture, performing kneading, a melt kneading step of forming a melt kneaded product, extruding the molten kneaded product from an extrusion die, and molding to obtain a molded product A waste disposal method, comprising: an extrusion molding step of forming; a cooling step of cooling the molded article to obtain a lump molded article; and a storage step of storing the lump molded article in a storage site in the administrative district. 33. The plastic waste is polyethylene, polypropylene, polystyrene, AS resin, AB
S resin, vinyl chloride resin, methacrylic resin, polyethylene terephthalate, polyvinylidene chloride, ethylene vinyl alcohol copolymer, ACS resin, ASA resin, A
33. The waste disposal method according to claim 32, wherein the waste is a general-purpose plastic waste containing at least one of ES resins. 34. A waste containing a metal component and a molten plastic waste are kneaded, cooled and solidified to form a lump-shaped molded product, and the lump-shaped molded product is stored. To collect the waste disposal method.