JP2001287991A - Abrasion resistant aggregate and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a new aggregate produced from a starting material consisting essentially of a burned ash from a refuge incinerator, and a thermite exothermic reagent, and excellent in abrasion resistance, and further to provide a method for producing the aggregate. SOLUTION: (1) This abrasion resistant aggregate comprises a material obtained by melting and solidified the starting material consisting essentially of the burned ash from the refuge incinerator, and the thermite exothermic reagent, and is characterized in that the solidified material contains 6-35% alumina component, and the amount of the remaining aluminum is <=0.2%. (2) The method for producing the aggregate is characterized in that the thermite exothermic reagent is mixed and melted with the burned ash from the refuge incinerator to provide a vitrified inorganic composition, and the melted material is gradually cooled and solidified.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an abrasion-resistant aggregate and a method for producing the same, and more particularly, it is produced from a starting material containing incinerated ash from a garbage incinerator and a thermite exothermic reactant as essential components. The present invention relates to a novel aggregate having excellent wear resistance and a method for producing the aggregate.

[0002]

2. Description of the Related Art As is well known, wastes discharged from factories and homes are increasing at an accelerating rate, and the remaining years of final disposal sites are becoming tight. There is a feeling that garbage fills the earth. Reducing garbage is an urgent issue. Incineration is most effective for volume reduction, but incineration ash is generated as a result. This incinerated ash is light and easily scattered, does not remain in landfills, and is very troublesome. As a recent tendency, there has been an attempt to melt and vitrify incinerated ash to reduce its volume and reuse it for civil engineering construction materials and the like. However, new problems have also arisen with the melting process. It is a problem that aluminum metal remains in the incineration ash. In recent years, the discharge of products such as aluminum beverage cans, aluminum foil, and laminates of aluminum foil on plastic confectionery bags has increased dramatically, and metallic aluminum has inevitably remained in the incineration ash of incinerators.
Metallic aluminum reacts with acidic or alkaline water to generate hydrogen, which in some cases can explode and cause personal injury. Even if the incinerated ash is melted and vitrified, the aluminum remains as it is, and the problem of hydrogen generation remains as it is, and cracks occur even when used for civil engineering construction materials. At present, it is difficult to develop a wide range of applications because the glass remains brittle due to the remaining aluminum. There is no use even if the volume is reduced. In addition to the problem of residual aluminum, incinerated ash also has a disadvantage that it has a large amount of a silica component and low strength, and is inferior in abrasion resistance. In order to use incinerated ash effectively, remove residual aluminum,
It is necessary to modify the component composition to have high strength and high abrasion resistance and to make the crystal structure of the molten and solidified product a slow cooling structure without distortion.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and a novel bone having high strength and excellent abrasion resistance, which solves the above-mentioned problems, using incinerated ash as a starting material. It is intended to provide materials and a method for producing the same.

[0004]

Means for Solving the Problems The present inventor has made intensive studies on the above problems and obtained the following findings. (1) The incineration ash of the refuse incinerator and the starting material containing the thermite exothermic reactant as essential components are melt-solidified, the amount of alumina of the solidified material is 6 to 35%, and the amount of residual aluminum is 0.2%. What can be solved by doing the following. And, (2) the above-mentioned melt-solidified substance is produced by mixing and melting the thermite exothermic reactant with the incineration ash of a garbage incinerator to forge a glassy inorganic composition, and gradually cooling and solidifying this melt. What you can do. And (3) the thermite exothermic reactant is obtained by mixing a powder containing an aluminum component and a powder containing an iron oxide component, and adjusting the aluminum content of the mixture to 5% or more, the aluminum component and the iron oxide component. Is most preferably 1: (2.0-5.0). (4) The aluminum content of the mixture of the powder and granules is 5% or more;
The ratio of the aluminum component to the iron oxide component is 1: (2.0 to 5.
0) Most preferably, the mixture contains 3 to 12% by weight of titanium oxide and 1 to 5% by weight of manganese oxide. (5) The pulverized waste aluminum can can be suitably used for the powder containing the aluminum component. (6) The residual aluminum ash can be suitably used for the powder containing the aluminum component. (7) The magnetic iron oxide sludge can be suitably used for the powder containing the iron oxide component. (8) Red mud from the production of alumina hydroxide can be suitably used for the powder containing the iron oxide component. (9) It is more preferable that the mixture of the granules and the incineration ash of the garbage incinerator are compression molded. (10) It is most preferable that the mixture of the above-mentioned powder and granules is mixed at 10 to 40% of the whole when mixed with the incineration ash of the refuse incinerator. The above findings were obtained. The present invention has been made based on the above findings.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The abrasion-resistant aggregate of the present invention can be obtained by melting and gradually cooling and solidifying a starting material containing incinerated ash and a thermite exothermic reactant as essential components. During the melting process,
The metallic aluminum remaining in the incineration ash changes into harmless inorganic compounds (mainly alumina). The reaction at this time is presumed to be due to the following mechanism. That is, thermite exothermic reactant aluminum reacts with iron oxide to cause a thermite exothermic reaction. At this time, the aluminum contained in the incineration ash also reacts at the same time, causing harmless inorganic substances (alumina).
It is presumed to change to Therefore, in the present invention, it is essential that a thermite reaction occurs. In order to cause a thermite reaction, the aluminum content in the thermite reactant is preferably 5% or more. If it is less than 5%, thermite exothermic reaction does not occur, which is not preferable. The mixing ratio of aluminum to iron oxide is preferably such that the aluminum content is 1 and the iron oxide content is 2.0 to 5.0. If the ratio of the aluminum-containing raw material to the iron oxide-containing raw material exceeds the upper limit, the amount of iron oxide becomes excessive and thermite exothermic reaction does not occur, which is not preferable. On the other hand, if the amount is less than the lower limit, aluminum is excessive and aluminum remains in the melt, which is not preferable.

[0006] When 3 to 12% by weight of titanium oxide and 1 to 5% by weight of manganese oxide are contained in the mixture, the melting point of the molten glass is lowered and the flowability is improved, so that the slag flows continuously without interruption. become. It is extremely important for stabilizing operations. When titanium oxide and manganese oxide are already contained in the aluminum raw material and the iron oxide raw material, it is sufficient to newly add a shortage of titanium oxide and manganese oxide. Titanium oxide and manganese oxide may be added by adding titanium oxide and manganese oxide itself,
Alternatively, those containing titanium oxide and manganese oxide components may be added. Most preferably, waste containing titanium oxide and manganese oxide is used.

[0007] If the titanium oxide content is less than the lower limit, the viscosity of the molten product increases, the meltability deteriorates, and continuous operation of the incinerator is not preferable. Further, even if the content exceeds the upper limit, no further improvement effect of the meltability can be expected. For the method of mixing these compositions, for example, it is only necessary to mix using a normal stirring mixer such as a fret mill, a high-speed mixer, a mixer, and the addition of titanium oxide, manganese oxide, etc., and the mixing method are also specially limited. Not necessarily.

Although there is no problem in practical use even if the shape of these compositions is in the form of powder, it is more preferable to form them into granules or granules having a size of 2 to 30 mm.
When granules and granules are formed, the density of the granules is higher than that of the granules, so that the propagation speed of combustion heat is high and a higher heat generation effect can be obtained. As the method of granulation or granulation, dry molding is preferable because the aluminum component constituting the composition easily reacts with moisture.

The component composition of the aggregate of the present invention is as follows.
It is preferable to set the content to 5% and the residual aluminum content to 0.2% or less, most preferably 0.0% or less. If the amount of residual aluminum in the aggregate is 0.2% or less, no trouble occurs in which hydrogen is generated during actual use and the aggregate collapses. Therefore, up to 0.2% is permissible. If it exceeds 0.2%, troubles of hydrogen generation and aggregate collapse occur, which is not preferable. Most preferably, it is 0.0% or less.

The aggregate of the present invention has high strength and high abrasion resistance when the amount of alumina in the aggregate increases, but when the amount of alumina is less than the lower limit, the strength and abrasion resistance required for the construction road aggregate. Can not be obtained. Ordinary incineration ash already contains about 10% of alumina, and if a thermite is added and melted, the amount of alumina in the melt exceeds 10%. If the road aggregate contains at least 6% alumina, the required minimum characteristics can be satisfied, so that the incinerated ash can be mixed with other materials having a low alumina component and diluted for use. As the diluent, waste materials having low alumina content such as fly ash (coal ash) and waste pottery stone can be effectively used.

In the present invention, when the mixing ratio of the thermite agent is increased, the amount of alumina formed as a result increases, and the alumina content of the aggregate increases. The amount of alumina in the aggregate is 3
If the thermit agent is added in an amount exceeding 5%, the flowability of the molten product becomes poor and continuous operation becomes difficult. Therefore, the amount of alumina in the aggregate needs to be suppressed to the upper limit (35%) or less. The mixing ratio of the thermite exothermic reactant is preferably 5 to 40% by weight, and most preferably 10 to 25% by weight of the total when mixed with the incineration ash. As described above, the addition exceeding the upper limit is not preferable because the fluidity of the melt becomes poor and continuous operation becomes difficult. On the other hand, if it is less than the lower limit, the residual aluminum in the aggregate exceeds 0.2%, which is not preferable. By the way, 15
% Or more, the residual aluminum becomes 0.0% or less.

The thermite reactant may be added in the form of aluminum or iron oxide, or may be added in the form of a powder containing these components. It is preferable to use a waste powder containing these components.

The powder containing aluminum component is most preferably a waste aluminum can for drinks or a powder of aluminum waste such as aluminum ash generated when aluminum metal is redissolved. It is not limited to only. Powders containing iron oxide components include general metal waste such as iron scrap, iron rust, dust collected from converter furnace and blast furnace dust generated in the steelmaking industry, and by-products during the production of magnetic iron oxide. However, the present invention is not limited to iron oxide sludge, which is generated as such, and red mud when producing aluminum hydroxide from bauxite. These powdery and granular raw materials may be used alone or as a mixture of two or more different starting raw materials.

[0014] The purity, shape, particle size,
The water content varies depending on the type and history of the starting materials,
Prior to the mixing of the raw materials and the adjustment of the components, pretreatments such as drying, crushing, crushing, and classification are appropriately performed according to the circumstances of each raw material. In the pretreatment method, since the purity, shape, moisture content, etc. of the waste material used vary widely, the most efficient and economic means may be appropriately selected in each case. For example, when a waste aluminum can is used as an aluminum-containing raw material, the purpose can be sufficiently achieved by crushing into small pieces of about 5 to 10 mm by a cutter and then secondary grinding to 1 to 3 mm or less. In addition, when a material having a high water content is used as the iron oxide-containing raw material, the content of water may be dried to about 5 to 1% by solar drying or the like. In order to further improve the mixing with the aluminum raw material, the lump is preferably finely pulverized.

[0015] The compression efficiency of the mixture of the powder containing the aluminum component and the powder containing the iron oxide component and the mixture of the incineration ash is increased if they are compression-formed before being put into a melting furnace. It can be compressed by up to about 40%, which increases the melting efficiency by 1.5 to 2 times.

It is preferable that the molten product is allowed to cool in the air to be slowly cooled and solidified. As a result, an inorganic glass composition having high strength and excellent abrasion resistance can be obtained. The obtained glass composition can be suitably used as a road aggregate. When used for the aggregate of the surface layer of an asphalt road, the abrasion resistance is improved by about 2 to 5 times as compared with the commonly used natural aggregate. Also, the abrasion resistance is improved by about 20 to 30 times as compared with a case where only incinerated ash is melted and water-cooled is used as an aggregate.

As the melting furnace used in the present invention, all existing furnaces for melting, such as a burner type melting furnace, an electric furnace and a coke oven, can be used.

[0018]

The present invention will be described by way of examples. Example 1 Thermite exothermic reactant Aluminum component: Use of aluminum can pulverized to 3 mm or less Iron oxide component: Use iron oxide sludge by-produced during the production of magnetic iron oxide Auxiliary raw material: Waste titanium oxide and manganese oxide Pulverized The above aluminum component, iron oxide component and auxiliary raw materials were mixed and mixed to the following composition (% by weight) to prepare a thermite exothermic reactant. Aluminum component: 15% Iron oxide component: 35% Titanium oxide: 5% Manganese oxide: 2% Granule molding The above-mentioned thermite exothermic reactant was mixed with an inorganic binder and molded into a ball having a size of 2 to 30 mm and solidified. After that, it is mixed with incineration ash from a garbage incinerator to make 10%
%, And 30% by weight, mixed and charged into a melting furnace of the structure shown in FIG. 1, which was fired by a heavy oil burner, melted at 1300 ° C., melted, and then allowed to cool in the air to be slowly cooled and solidified. The molten slag is
Each of the compositions had excellent meltability, and flowed continuously without interruption until the incinerator was stopped. At the bottom of the slag chamber of the melting furnace, molten iron was separated from the slag and accumulated.
The amount of alumina in the incinerated ash used was 24% and the amount of aluminum was 0.89%, but the amount of residual alumina in the molten and solidified material was as follows: Composition: 0.15% Composition: 0.00% Composition: 0.00%. On the other hand, the amount of alumina in the molten and solidified product was as shown in Table 1 below. In each case, the amount of oxides of alkali metals such as sodium and potassium in the melt was reduced. The molten solid was immersed in alkaline or acidic water, but no hydrogen was generated. Next, the melt was crushed and used as an aggregate of the asphalt surface layer, and the wear resistance as a road aggregate was examined. The results are as shown in Table 2.

Example 2 Thermite exothermic reactant Aluminum raw material: A material obtained by pulverizing aluminum residual ash generated when aluminum metal was redissolved Iron oxide raw material: Red mud used in the production of aluminum hydroxide from bauxite Raw materials: Titanium oxide and manganese oxide wastes were crushed and used. The above aluminum raw materials, iron oxide raw materials, and auxiliary raw materials were mixed and prepared into the following composition. Aluminum component: 18% Iron oxide component: 40% Titanium oxide: 5% Manganese oxide: 2% Granulation molding The above mixture was mixed with water glass to form a round ball of 10 to 30 mm, dried, and hardened. Thereafter, this was mixed with the incineration ash of a garbage incinerator, added and mixed at 20% by weight of the whole, compressed by 40% with a press, and charged into an electric furnace.
After melting at room temperature, the mixture was allowed to cool in air to be slowly cooled and solidified. Molten slag has excellent flowability, and it takes 24 hours to shut down the furnace.
It was able to operate continuously for hours. The residual aluminum content of the incinerated ash before melting was 0.6%. The residual aluminum content after the melting was 0.0%. The molten incineration ash was immersed in acidic water, but no hydrogen was generated. The melt was crushed and used as road aggregate.
The abrasion resistance was three times that of the case where the same amount of natural aggregate was used.

[0020]

As described above in detail, the present invention is intended to reduce the troublesome waste such as incinerator ash, aluminum ash, iron oxide sludge and the like for civil engineering construction which has excellent abrasion resistance. It can be recycled into materials and makes a great contribution to resource recycling.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a melting furnace used in an embodiment of the present invention.

Claims (10)

[Claims] An incinerated ash from a refuse incinerator and a starting material having a thermite exothermic reactant as essential components are melted and solidified, and the solidified material contains 6 to 35% of an alumina component,
A wear-resistant aggregate having a residual aluminum content of 0.2% or less. 2. An abrasion resistant bone characterized in that a thermite exothermic reactant is mixed and melted into incineration ash of a refuse incinerator to forge a glassy inorganic composition, and the melt is gradually cooled and solidified. The method of manufacturing the material. 3. The thermite exothermic reactant comprises a mixture of a granular material containing an aluminum component and a granular material containing an iron oxide component, wherein the mixture has an aluminum content of 5% or more and an aluminum component and an iron oxide component. A method for producing a wear-resistant aggregate, wherein the ratio is 1: (2.0 to 5.0). 4. An aluminum content of the mixture of the powder and granules is 5%.
Above, the ratio of the aluminum component to the iron oxide component is 1: (2.0 to
5.0) and in the mixture, titanium oxides 3 to 12
A method for producing an abrasion-resistant aggregate, comprising 1% to 5% by weight of manganese oxide. 5. The method for producing an abrasion-resistant aggregate according to claim 2, wherein the powder containing the aluminum component is a crushed product of a waste aluminum can. 6. The method for producing an abrasion-resistant aggregate according to claim 2, wherein the powder containing the aluminum component is aluminum residual ash. 7. The method for producing an abrasion-resistant aggregate according to claim 2, wherein the granular material containing the iron oxide component is a magnetic iron oxide sludge. 8. The method for producing an abrasion-resistant aggregate according to claim 2, wherein the powder containing the iron oxide component is red mud from alumina hydroxide. 9. The method for producing an abrasion-resistant aggregate according to claim 2, wherein the mixture of the granules and the incineration ash of a garbage incinerator are compression-molded. 10. Abrasion resistant according to any one of claims 2 to 9, wherein said mixture of powder and granules is mixed in an amount of 10 to 40% of the whole when mixed with incineration ash of a garbage incinerator. Method for producing wearable aggregate.