JP2002220744A - Inorganic fiber and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high-strength inorganic fiber made from incinerated ash as a main raw material, and a method for producing the inorganic fiber. SOLUTION: This method for producing the inorganic fiber is characterized by comprising a step of mixing the refuse incinerated ash with a thermite exothermic reactant, a step of melting the resultant mixture with an oxidation flame and converting the mixture into a slag, a step of making the slag flow into a well, a step of making the slag flowing into the well stay in the well, settling and separating a molten metal in the slag, a step of overflowing the molten slag from a weir of the well and pouring the molten slag into a holding furnace, a step of regulating components of the slag in the holding furnace and a step of making the molten slag flow down from the holding furnace and forming the molten slag into a fiber.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an inorganic fiber and a method for producing the same, and more particularly, to an inorganic fiber using refuse incineration ash as a main raw material and a method for producing the same.

[0002]

2. Description of the Related Art As is well known, refuse discharged from factories and homes is increasing at an accelerating rate, and reducing the volume of refuse is an urgent issue. Incineration is most effective for volume reduction, but incineration ash is generated as a result. Since the incinerated ash is light and easily scattered, it does not remain in the landfill, and recently, the incinerated ash has once been vitrified. Eventually, a system for vitrifying and using incinerated ash is being established. The question is how to use the molten incineration ash. At present, some are used as roadbed materials, tiles and aggregates, and as a high value-added commercial material, fiberization and use as rock wool (Japanese Unexamined Patent Publication No. Hei 10-273332) have been attempted. Rock wool is far from practical. Waste incineration ash has large fluctuations in the composition of the molten glass due to drastic fluctuations in the composition of the raw material, and the most difficult problem is that metal aluminum, carbon, sulfur, metal iron, etc. remain in the molten slag, resulting in fiber This is because the strength is weak. The cause is that municipal garbage is inevitably mixed with aluminum used in daily life, such as aluminum cans and aluminum foil, and remains in the slag without being oxidized during the melting process, and during the production of rock wool. There is also a problem with the slag melting method described above, which causes aluminum, carbon, sulfur and iron to remain without being oxidized. In other words, rock wool is used as a raw material in the form of a molten slag in a melting furnace, cooled once, and then melted again in a cupola and arc electric furnace to form fibers.However, both cupola and arc electric furnaces are melted in a reducing atmosphere. This is because aluminum, carbon, sulfur, and iron remain without being oxidized. In addition, new carburization and vulcanization from coke must be taken into account in cupola dissolution.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems.
It is an object of the present invention to provide a method capable of forming a fiber as it is without leaving carbon, sulfur, iron and the like, and to provide the fiber.

[0004]

Means for Solving the Problems The present inventor has conducted intensive studies in view of the above problems and found that the following means can solve the problems.

An inorganic fiber which is obtained by melting waste incineration ash as a main raw material and melting said incineration ash into fibers, and having the following composition. Al2O3: 20~35 SiO2: 15~40 Fe2O3: 5~20 CaO: 20~45 MgO: 3~20 MnO: 3~15 R 2 O: 5% or less Fe: 0.3% or less C: 0.3% S: 0.3% or less Al: 0.3% or less Other unavoidable components + R ₂ O: 10% or less

2. A step of mixing the incineration ash and thermite exothermic reactant, a step of melting the mixture with an oxidizing flame to form a slag, and a step of holding the slag in a holding furnace to precipitate molten metal in the slag. A method for producing inorganic fibers, comprising: a separating step; a step of adjusting slag components in the holding furnace; and a step of flowing molten slag from the holding furnace to fibrillate.

3. A step of mixing the incineration ash and thermite exothermic reactant; a step of melting the mixture with an oxidizing flame to form slag; a step of flowing the slag into a basin; A step of sedimenting and separating the molten metal in the slag by staying in the pool, a step of overflowing the molten slag from the pool weir and injecting it into a holding furnace, and a step of adjusting the slag components in the holding furnace. And a step of flowing molten slag from the holding furnace to fiberize the molten slag.

4. The thermite exothermic reactant is obtained by mixing a particulate material containing an aluminum component and a particulate material containing an iron oxide component as essential components, and the content of the aluminum component in the reactant. 5% or more, the ratio of the aluminum component to the iron oxide component is 1: (2.0 to 5.0), and 5 to 40% is mixed with the incinerated ash. 4. The method for producing an inorganic fiber according to any one of claims 1 to 3.

5. The method for producing an inorganic fiber according to claim 4, wherein the mixture of the granules is granulated or granulated.

6. The method according to claim 4, wherein the mixture of the powdery and granular materials is divided into small portions, placed in a bag, and mixed with the incineration ash.
3. The method for producing an inorganic fiber according to item 1.

7. The method for producing inorganic fibers according to claim 4, wherein the mixture of the powdery and granular materials is divided into capsules, mixed with incinerated ash, and mixed.

8. The method for producing an inorganic fiber according to claim 4, wherein the particulate material containing the aluminum component is a crushed product of a waste aluminum can.

9. The method for producing an inorganic fiber according to claim 4, wherein the particulate material containing an aluminum component is aluminum residual ash.

10. The method for producing an inorganic fiber according to claim 4, wherein the material containing the iron oxide component is magnetic iron oxide sludge.

11. The method for producing an inorganic fiber according to claim 4, wherein the material containing the iron oxide component is red mud during the production of alumina hydroxide.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The thermite exothermic reactant of the present invention has an auxiliary effect as a heat source for melting incinerated ash,
The greatest effect is the mixing and disruption of incineration ash.
Thermite exothermic reactant mixed with the incineration ash has a strong high-temperature explosive action during the reaction, which violently disturbs the incineration ash, frequently causes the lower layer and the upper layer to be exchanged, and the residual carbon, sulfur, Aluminum and the like are always exposed to the heating atmosphere. Since an oxidizing flame is used for heating, residual carbon and sulfur are oxidized and burned off. Aluminum is also oxidized and changes to aluminum oxide. It is also presumed that the metal aluminum contained in the incinerated ash reacts simultaneously with the reaction of the thermite exothermic reactant to convert to aluminum oxide. According to the method of the present invention, residual carbon, sulfur,
Aluminum can both be reduced to 0.3% or less.

Further, Na represented by the chemical formula of R ₂ O
_{2 O,} K 2 _O is then dispersed gas by high temperature reaction of the thermite exothermic agent, the total amount can be reduced to 5% or less.

The inorganic fiber of the present invention preferably has the following composition range. Al2O3: 20~35 SiO2: 15~40 Fe2O3: 5~20 CaO: 20~45 MgO: 3~20 R 2 O: 5% or less Fe: 0.3% or less MnO: 3~15 C: 0.3% S: 0.3% or less Al: 0.3% or less Other unavoidable components + R ₂ O: 10% or less

In the present invention, since the thermite exothermic reactant is used, the alumina content generated by the thermite exothermic reaction is usually added to the alumina content contained in the incineration ash. Ordinary incineration ash contains more than ten percent of alumina, but if the amount of alumina after melting is less than 20%, a sufficient amount of thermite exothermic reactant is added, so that sufficient incineration of the incineration ash is expected. Can not. It is necessary to add a thermite exothermic reactant to at least 20% or more in order to cause a disturbing action freely. On the other hand, if it exceeds the upper limit, the viscosity of the molten incinerated ash becomes large, and it becomes difficult to form fibers. If the content of SiO2 is less than the lower limit, sufficient heat resistance cannot be obtained. If it exceeds the upper limit, the viscosity becomes large and fiberization becomes difficult. CaO, MgO, and MnO are necessary to lower the viscosity of the molten slag, and if it is less than the lower limit, the viscosity cannot be sufficiently reduced. Addition exceeding the upper limit is not preferred because it causes a decrease in heat resistance. Fe2O3 is preferably in the above range in terms of fiber strength. R ₂ O is preferably at most 5%. If the upper limit is exceeded, the heat resistance will be reduced and the fibers will be brittle. F
e, C, S, and Al are all preferably 0.3% or less. Exceeding the upper limit is not preferable because the fiber breaks.

In the present invention, molten iron is generated by a thermite exothermic reaction, so that the molten slag is temporarily stored in a pool, and the iron is submerged and separated. In addition, slag is stored in a holding furnace for component adjustment, and components are added here to adjust to the target components. In the process of holding in a holding furnace, unseparated iron is settled and separated.

[0010] The slag is fiberized by flowing molten slag from a holding furnace and blowing it off with a high-speed rotating body utilizing centrifugal force. Alternatively, the fibers are blown off with compressed air to form fibers. Alternatively, the fibers are formed by a method using both of them.

The mixing ratio of the thermite reactant is 5 to 40.
% Is preferred. This is for the following reasons.
That is, the thermite reaction involves a violent disturbance and heat generation during the reaction, but when the reaction is weak, it stays only on the surface and does not propagate to the bottom. In order to disturb the incineration ash by the disturbing action and replace the incineration ash on the surface and the bottom, and to infiltrate the reaction heat to the bottom and to form a deep pool, it is necessary to mix at least a certain amount, and mix at least 5% or more. It is necessary. The upper limit is preferably about 40%. Mixing more than the upper limit increases the viscosity of the molten incinerated ash, which is not preferable.

The thermite exothermic reactant comprises a mixture of a raw material containing an aluminum component and a raw material containing an iron oxide component. Examples of the raw material containing an aluminum component include waste aluminum cans for beverages and waste containing an aluminum component such as residual aluminum ash generated when aluminum metal is redissolved, but are not limited thereto. Raw materials containing iron oxide components are iron scrap,
Common metal waste such as iron rust, dust collection ash such as converter dust and blast furnace dust generated in the steel industry, iron oxide sludge generated as a by-product during the production of magnetic iron oxide, and aluminum hydroxide from bauxite Red mud during production is effective, but is not limited thereto. These raw materials may be used as a single type,
Alternatively, two or more kinds of starting materials different from each other may be appropriately mixed and used.

[0013] As described above, when the aluminum-containing raw material is a crushed piece of an aluminum can, a mixture obtained by mixing with the iron oxide-containing raw material is pressed into a plate shape, divided into appropriate sizes, and divided into incinerated ash. They may be mixed and dispersed. The thickness of the crimping piece is preferably about 3 to 6 mm and the length is about 5 to 30. Adhesive components remain on the pressure-bonded pieces from which the water in the aluminum can is evaporated, and moderate strength is exhibited. The size of the crushed piece of the waste aluminum can may be such that the crushed piece is crushed into small pieces of about 5 to 10 mm by a cutter and then secondarily crushed to 1 to 3 mm or less. When iron oxide sludge by-produced during the production of magnetic iron oxide is used as the iron oxide-containing raw material, the moisture content may be dried to about 5 to 1% by sun drying or the like. In order to further improve the mixing with the aluminum raw material, the lump is preferably finely pulverized.

The aluminum content in the thermite reaction composition containing the aluminum-containing raw material and the iron oxide-containing raw material as the main raw materials 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 and iron oxide is preferably such that the aluminum content is 1 and the iron oxide content is 2.5 to 6, and the mixture contains 3 to 12% by weight of titanium oxide and 1 to 3% by weight of manganese oxide. It is preferable to include them. When titanium oxide and manganese oxide are already contained in the aluminum raw material and the iron oxide raw material, after mixing the aluminum raw material and the oxidized raw material, the shortage of titanium oxide and manganese oxide may be newly added. Regarding the method of adding titanium oxide and manganese oxide, titanium oxide and manganese oxide may be added, or titanium oxide and manganese oxide may be added.
A material containing a manganese oxide component may be added. It is also effective to add waste particles containing titanium oxide and manganese oxide.

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 thermit exothermic reaction does not occur, which is not preferable. On the other hand, if it is less than the lower limit, the amount of aluminum is excessive, which is not preferable.

If the content of titanium oxide is less than the lower limit value, the viscosity of the thermite reaction product is so high that the meltability deteriorates and continuous operation is not possible, which is not preferable. Further, even if the content exceeds the upper limit, no further improvement in the meltability can be expected.

Although there is no problem in practical use even if the thermite is in the form of a powder, it is more preferable to form it into granules or granules. 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.

When the thermite exothermic reactant is mixed with the incinerated ash, the thermite exothermic reactant may be divided into small portions and placed in a bag of resin or the like or in a combustible capsule and mixed with the incinerated ash.

The incinerated ash is melted by flame heating. The flame adjusts to the oxidizing flame and melts. As the melting furnace, any furnace having a structure capable of flame heating can be used, but a surface melting furnace having an inclined hearth is most preferable. FIG. 1 is an explanatory diagram of a surface melting furnace having an inclined hearth, a holding furnace, and a spinner rotating at high speed. In FIG. 1, the incinerated ash is pushed by a pusher 2 to the top of the inclined hearth 3 in the furnace. The incinerated ash pushed into the furnace pushes the previously put incinerated ash from behind, and pushes the previously put incinerated ash down the slope of the hearth down. A burner 4 opens in the furnace ceiling toward the inclined hearth, and the flame heats the incineration ash placed on the hearth surface. The incinerated ash is heated by the burner flame while flowing down the slope of the hearth, melts and melts, flows as slag, and accumulates in the pool 5 provided at the lower end of the hearth. In the slag of the pool, the iron sinks below, where the slag and iron are separated. The slag overflowing from the weir falls down and falls into the holding furnace 6. The slag that has fallen downward from the holding furnace is blown off by the spinner 7 that rotates at a high speed, and is fiberized and solidified.

In the holding furnace, components are adjusted mainly for adjusting viscosity and fire resistance. SiO2, CaO, MgO, Mn
The components are adjusted by adding O, TiO2, Fe2O3 and the like. In the holding furnace, unseparated iron is settled and separated again.

[0021]

The present invention will be described by way of examples. Example 1 A thermite reactant having the following composition was mixed with incinerated ash and melted with an oxidizing flame, and the molten slag was examined for residual aluminum, carbon and sulfur. The composition of the thermite reactant is as follows. Aluminum raw material: Aluminum raw material obtained by crushing aluminum ash generated during remelting of aluminum ingot was used. Iron oxide component: The iron oxide component used was red mud when aluminum hydroxide was produced from bauxite. Pulverized waste of titanium oxide and manganese oxide was used as an auxiliary material.

The above aluminum raw material, iron oxide raw material, and auxiliary raw material were mixed and prepared into the following composition (% by weight). Aluminum component: 18% Iron oxide component: 40% Titanium oxide: 5% Manganese oxide: 2% 150 g of the above mixture was put into a polyethylene bag,
This was supplied from a hopper and mixed with 10% by weight of incinerated ash.

Burner fuel uses kerosene, 1300 ° C
Melted in an oxidizing flame. The molten incineration ash and the thermite produced slag with a low melting point and flowed continuously until the incinerator was shut down due to its excellent meltability. As a comparative example, a sample in which the thermite exothermic reactant was not added and a case in which it was dissolved in a reducing flame was also prepared.

Result Residual aluminum, carbon, and sulfur in slag Residual aluminum When melted without adding a thermite reactant, 0.7-1.0% aluminum remained in both oxidized and reduced flames. With the addition of thermite reactant, 0.0
% And 0.1% in the reducing flame. Carbon and sulfur In the oxidation flame with the addition of thermite reactant, both carbon and sulfur were 0.1% or less.

[0025]

Example 2 The melting test of incinerated ash was performed using the following thermite reactant. The composition of the thermite reactant is as follows. Aluminum raw material: Use aluminum can crushed to 3mm or less Iron oxide component: Use iron oxide sludge by-produced during the production of magnetic iron oxide Auxiliary raw material: Titanium oxide and manganese oxide waste

The above aluminum raw material, iron oxide raw material, and auxiliary raw material were mixed and prepared into the following composition (% by weight). Aluminum component: 15% Iron oxide component: 35% Titanium oxide: 5% Manganese oxide: 2% The above mixture was stretched and pressed on a 4 mm-thick plate by a press.
This was cut into a length of 5 to 30 mm, and 20% by weight of incinerated ash was supplied from a hopper and mixed.

The burner fuel uses kerosene, 1350 ° C.
Melted in an oxidizing flame. The molten incineration ash and the thermite produced slag with a low melting point and had excellent melting properties and flowed continuously until the melting furnace was stopped. For the production of inorganic fibers, the melting furnace, holding furnace and spinner shown in FIG. 1 were used. In the holding furnace, a small amount of calcia was added. The holding furnace was kept at 1500 ° C. and dropped on a spinner. An inorganic fiber having the following composition was obtained. Alumina: 30% Silica: 33% Iron oxide: 7% Calcia: 21% Magnesia: 4% Manganese oxide: 1% Na2O + K2O: 3.8% Carbon: 0.1% Sulfur: 0.0% Aluminum: 0.0% Residual component: 0.1% An inorganic fiber excellent in flexibility without cutting was obtained.

As has been described in detail above, the present invention is one in which garbage incineration ash can be used as a main raw material and can be directly fiberized from a melting furnace for incineration ash, which greatly contributes to the effective use of incineration ash. It is.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of the method of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Melting furnace 2 ... Pusher 3 ... Inclination hearth 4 ... Burner 5 ... Puddle 6 ... Holding furnace 7 ... Spinner

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Claims (11)

[Claims] An inorganic fiber which is obtained by melting waste incineration ash as a main raw material and melting said incineration ash into fibers. Al2O3: 20~35 SiO2: 15~40 Fe2O3: 5~20 CaO: 20~45 MgO: 3~20 MnO: 3~15 R 2 O: 5% or less Fe: 0.3% or less C: 0.3% S: 0.3% or less Al: 0.3% or less Other unavoidable components + R ₂ O: 10% or less 2. A step of mixing the incineration ash and thermite exothermic reactant, a step of melting the mixture with an oxidizing flame to form a slag, and a step of holding the slag in a holding furnace to precipitate molten metal in the slag. A method for producing inorganic fibers, comprising: a separating step; a step of adjusting slag components in the holding furnace; and a step of flowing molten slag from the holding furnace to fibrillate. 3. A step of mixing the incineration ash and thermite exothermic reactant; a step of melting the mixture with an oxidizing flame to form slag; a step of flowing the slag into a basin; A step of sedimenting and separating the molten metal in the slag by staying in the pool, a step of overflowing the molten slag from the pool weir and injecting it into a holding furnace, and a step of adjusting the slag components in the holding furnace. And a step of flowing molten slag from the holding furnace to fiberize the molten slag. 4. The thermite exothermic reactant is obtained by mixing a particulate material containing an aluminum component and a particulate material containing an iron oxide component as essential components, and the content of the aluminum component in the reactant. 5% or more, the ratio of the aluminum component to the iron oxide component is 1: (2.0 to 5.0), and 5 to 40% is mixed with the incinerated ash. 4. The method for producing an inorganic fiber according to any one of claims 1 to 3. 5. The method for producing an inorganic fiber according to claim 4, wherein the mixture of the granules is granulated or granulated. 6. The method according to claim 4, wherein the mixture of the powdery and granular materials is divided into small portions, placed in a bag, and mixed with the incineration ash.
3. The method for producing an inorganic fiber according to item 1. 7. The method for producing inorganic fibers according to claim 4, wherein the mixture of the powdery and granular materials is divided into capsules, mixed with incinerated ash, and mixed. 8. The method for producing an inorganic fiber according to claim 4, wherein the particulate material containing the aluminum component is a crushed product of a waste aluminum can. 9. The method for producing an inorganic fiber according to claim 4, wherein the particulate material containing the aluminum component is aluminum residual ash. 10. The method for producing an inorganic fiber according to claim 4, wherein the material containing the iron oxide component is magnetic iron oxide sludge. 11. The method for producing an inorganic fiber according to claim 4, wherein the material containing the iron oxide component is red mud during the production of alumina hydroxide.