JPH0788247B2 - Manufacturing method of molded products using slag - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing a molded product such as a transparent horizontal plate and an ashtray using a powdery granular slag obtained by melting industrial waste.

Background Art In large cities, almost all roads are paved with asphalt. On such roads, rainwater, etc. does not penetrate from the paved road surface to the stratum below. As a result, the formation is dry,
Problems are occurring in the biological system in the ground. In addition, rainwater concentrates on the paved road surface and floods easily occur.

Therefore, it has been expected to develop an inexpensive pavement material having water permeability.

Problem to be Solved by the Invention An object of the present invention is to provide a method for producing a molded product having desired water permeability by using a slag obtained by melting inexpensive industrial waste.

Means for solving the problem The present invention, magnetic separation of the powdery granular slag that has been subjected to dissolution treatment of industrial waste, pulverized and sieved to divide into coarse particles of 1.0 mm ~ 4.0 mm and fine particles of less than 1.0 mm, 5 to 20 parts by weight of bentonite is added to 100 parts by weight of mixed slag of 20 to 80% of coarse particles and 80 to 20% of fine particles, and the resulting mixture is compressed to 200 kg / cm ² or more and compression molded to 700 ° C. The above is a method for producing a molded product using slag, which is characterized by firing.

In the present invention, the mixed slag has a coarse grain of 25 to 80% and a fine grain of 75%.
It is characterized in that it is a mixture with 20%, the firing temperature is 700 ° C or higher, and the molded product is a water-permeable flat plate.

In the present invention, the mixed slag is composed of coarse particles of 20 to 50% and fine particles of 80%.
It is a mixture with 50 to 50%, the firing temperature is 1000 ° C. or higher, and the molded product is a water-permeable flat plate having high compressive strength.

According to the present invention, iron particles are removed by magnetic separation of the powdery and granular slag obtained by subjecting the industrial waste to melt processing, and bentonite as a binder is added thereto, followed by compression molding and firing. This slag is sieved into coarse particles having a particle diameter of 1 to 4 mm, particle diameters less than 1 mm and fine particles, and particles having a particle diameter of 4 mm or more are crushed. (A) 20 to 80% coarse particles and 80 to 20% fine particles of this slag
By mixing (b) 5 to 20 parts by weight of bentonite to 100 parts by weight of the slag, (c) compression molding at a pressure of 200 kg / cm ² or more, and (d) firing at 700 ° C. or more. As a result, a molded product can be obtained.

Since the granular slag is magnetically selected in advance, iron content is removed,
It prevents iron content from appearing on the surface of the molded product and a rusty color is conspicuous, and also prevents the iron content in the area where iron content is present from leaving a recessed hole and impairing the appearance and lowering the strength. Be done.

Regarding the mixing ratio of coarse particles and fine particles, the larger the number of coarse particles, the higher the water permeability can be, but the compressive strength decreases. If the coarse particles exceed 80%, the strength generally usable cannot be maintained. Further, in order to reduce the coarse particles to less than 20%, the amount of slag to be crushed increases, which is contrary to the gist of the present invention of using an inexpensive raw material.

Generally, for the purpose of producing a water-permeable flat plate, a slag containing 25 to 80% of coarse particles is suitable in view of water permeability. It is necessary to consider the water permeability and high compressive strength of a water-permeable flat plate for highways and airfields, and slag with coarse particles of 20 to 50% is preferably used.

The higher the firing temperature, the higher the compressive strength of the product obtained. 70
If the firing temperature is less than 0 ° C, generally usable strength cannot be obtained. The baking temperature of 700 ° C. is sufficient for general water-permeable flat plates, but the baking temperature of 1000 ° C. or higher is required for high compressive strength water-permeable plates.

The amount of bentonite added is 5 with respect to 100 parts by weight of slag.
If it is less than part by weight, the function as a binder is not achieved,
Even if the amount exceeds 20 parts by weight, the function as a binder does not change, and bentonite is expensive, so the limit is 20 parts by weight.

Example FIG. 1 is a diagram showing a process for explaining an example of the present invention, FIG. 2 shows a transparent horizontal plate for road pavement manufactured by the process, and FIG. ) Indicates an ashtray. The industrial waste is melted in a melting treatment furnace, and the molten slag obtained therefrom is water-cooled in step n1 in FIG.
Thus, a granular slag is obtained. Industrial wastes include sewage sludge and its incinerated ash, municipal solid waste and its incinerated ash, coal ash, non-combustible materials such as stone dust and alumina, and construction waste materials. As an example,
Table 1 shows the ash composition of the sewage sludge molten slag.

This water-cooled slag contains about 20% water.

Therefore, in step n2 of FIG. 1, the slag is put in a flat-bed container and dried with a dryer at 100 ° C. for 8 hours to make the water content zero.

In step n3, the slag is magnetically selected to remove iron. That is, iron, which is a ferromagnetic material, is removed. Therefore, magnetic separation can be performed by providing a magnet in the powdery granular slag that does not contain water and removing iron and the like adhering to the magnet.

Then, in step n4, the slag is crushed and sieved. Part of the slag is fretting and sieving
A coarse powder having a particle size distribution shown by line 11 in the figure is obtained.
This coarse powder has a particle size of, for example, 1.0 or more and less than 4.0 mm. The remaining slag is ground in a ball mill and sieved to obtain fine powder having a particle size distribution shown by line 12 in FIG. The fine powder has a particle size of about 0.05 or more and less than 1.0 mm.

In step n5, 80 parts by weight of the coarse powder and 20 parts by weight of the fine powder described above are mixed, and bentonite 5 is used to produce a transparent horizontal plate.
.About.20 parts by weight and 5 to 8 parts by weight of water are further added.

In manufacturing the ashtray, 5 to 10 parts by weight of bentonite and 7 to 10 parts by weight of water are added to 80 parts by weight of the coarse powder and 20 parts by weight of the fine powder described above. Thus, the coarse powder, fine powder, bentonite and water are prepared and mixed. Therefore, in step n6, kneading is performed in the wet pan for 30 minutes, for example.

In step n7, the kneaded mixture is put into a mold and compression molded. This pressure is, for example, 200 kg / cm ² .

Then, this semi-finished product is exposed to sunlight and dried in the sun in step n8.

Then, in step n9, firing is performed. Maximum temperature during firing is 10
When the temperature is 00 ° C., the hydraulic conductivity shown by line 13 in FIG. 4 and the compressive strength shown by line 15 in FIG. 5 are obtained. The maximum temperature during firing is 70
When the temperature is 0 ° C., the hydraulic conductivity shown by the line l4 in FIG. 4 and the compressive strength shown by the line l6 in FIG. 5 are obtained. In FIG. 4 and FIG. 5, the compression pressure in step n7 is 200 kg / cm ² , and bentonite as a binder is contained at 5% by weight. Process n4
It is understood that it is possible to adjust the water permeability and further the compressive strength by changing the compounding ratio of the coarse powder and the fine powder obtained in 1. and changing the firing temperature. According to the experiments conducted by the inventors of the present invention, it was found that the hydraulic conductivity and the compressive strength also change when the particle size of slag, the composition ratio of slag and bentonite, the pressure during compression molding, and the like are changed. It was

The temperature change with time during firing is changed as shown in FIG. In Figure 6, the maximum temperature during firing is 1000 ° C.
And the 1000 ° C state is maintained for 1 hour.

By using a nitriding furnace for firing and firing the semi-finished product to be fired in a nitrogen atmosphere, the fired product can be made black, for example. When this firing atmosphere is air, the resulting product becomes brown. In this way, by changing the atmosphere gas at the time of firing, it is possible to change and adjust the color of the obtained product.

The permeable horizontal plate used for road pavement is stipulated in the Japanese Industrial Standard to have a permeability coefficient of 1.0 × 10 ^-3 cm ² / sec or more. For this purpose, as is clear from FIG. 4, when the maximum temperature during firing is 1000 ° C., it is necessary that the coarse powder is 50% by weight or more and less than 80% by weight, and the fine powder 20% by weight or more and less than 50% by weight. is there. The maximum temperature during firing is 700
It can be seen that when the temperature is ° C, the coarse powder is 25% by weight or more and less than 80% by weight, and the fine powder is 20% by weight or more and less than 75% by weight.

For curved bends on expressways and runways on airfields, transparent horizontal plates with a compressive strength of 1000 kg / cm ² or more and excellent wear resistance are required. For this, the fifth
As shown in the figure, when the maximum temperature during firing is 1000 ° C,
It is necessary that the coarse powder is less than 50 parts by weight and the fine powder is 50 parts by weight or more. Therefore, referring to Fig. 4 and Fig. 5, when the maximum temperature during firing is 1,000 ° C, the required coefficient of permeability and compressive strength are about 50 parts by weight of coarse powder and 50 parts by weight of fine powder. It turns out that

By changing the color of the product by changing the type of atmospheric gas at the time of firing to nitrogen air or other types as described above, it can be used as a marker to display the lane of a paved road with a transparent horizontal plate. When used in ashtrays, etc., the aesthetics are improved.

Since the slag used in the present invention is once melted in the melting treatment furnace, the shrinkage rate during firing in step n9 is extremely small, for example, 2% or less, and thus has the desired shape and dimension. It is possible to manufacture a molded product accurately.

The physical properties of the transparent horizontal plate and the ashtray thus obtained are
It is as shown in the table.

Effects As described above, according to the present invention, it becomes possible to easily manufacture a molded product whose permeability can be adjusted to a desired value,
For example, the present invention can be widely applied to applications such as a horizontal plate having a high water permeability and an ashtray having a low water permeability and not passing water.

Further, it is an inexpensive powder-granular slag obtained by melting and processing such industrial waste, can be obtained in a large amount, and can meet a large amount of demand.

[Brief description of drawings]

FIG. 1 is a diagram showing a process of an embodiment of the present invention, FIG. 2 is a perspective view showing a product manufactured by the process shown in FIG. 1, and FIG. 3 is a grain size of slag as a raw material. A graph showing the distribution, FIG. 4 is a graph showing the hydraulic conductivity after the firing step, and FIG.
FIG. 6 is a graph showing the compressive strength after the firing step, and FIG. 6 is a graph showing the change over time in the firing temperature in the firing step.

Claims (3)

[Claims] 1. A powdery slag obtained by subjecting industrial waste to dissolution treatment is magnetically separated, and is pulverized and sieved to separate coarse particles of 1.0 mm to 4.0 mm and fine particles of less than 1.0 mm to obtain coarse particles of 20 to 80%. Characterized by adding 5 to 20 parts by weight of bentonite to 100 parts by weight of mixed slag with 80 to 20% of fine particles, pressurizing the resulting mixture to 200 kg / cm ² or more, compression molding and firing at 700 ° C or more A method for producing a molded article using slag. 2. The mixed slag comprises coarse particles of 25 to 80% and fine particles of 75 to
Is a mixture with 20%, the firing temperature is 700 ℃ or more,
The method for producing a molded article using the slag according to claim 1, wherein the molded article is a water-permeable flat plate. 3. The mixed slag comprises coarse particles of 20 to 50% and fine particles of 80 to 50%.
Is a mixture with 50%, the firing temperature is 1000 ℃ or more,
The method for producing a molded product using slag according to claim 1, wherein the molded product is a water-permeable flat plate having high compressive strength.