JPH0819768A - Manufacture of road pavement material using waste - Google Patents

Abstract

PURPOSE:To stabilize the quality, if incineration ash is used and at the same time, make it possible to consume a large quantiy of other waste. CONSTITUTION:In cineration ash to be used is of a polymer. Washed sand as an aggregate is dried at about 200 deg.C and classified as 20-to 60-mesh sizes by a sieve. A ceramic waste is classified to 7-to-20 mesh sizes using a sieve after crushing for use. These materials are stirred and mixed, then are kneaded by adding water, and are granulated, dried into a body. Next, the body is formed using a hydraulic press at 200kgf/cm<2>, and the molding is baked in an electric furnace at 1075 deg.C.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to waste such as incinerated ash obtained by incinerating sludge generated by sewage treatment, sand settled by sewage treatment, sand washing, and used porcelain waste generated by sewer construction. The present invention relates to a method for producing a road pavement material excellent in water permeability and strength by utilizing.

[0002]

BACKGROUND OF THE INVENTION From waste, especially sewage treatment systems,
Sewage sludge incineration ash (hereinafter referred to as incineration ash) obtained by incinerating sludge recovered from the sedimentation tank after concentration, digestion, dehydration, and
Settled sand collected during dredging of pipes and the like, and washed sand obtained by washing this sand with water are generated, and used sewer pipes, which are used ceramic pipes, are generated. These are usually disposed of in landfills, but with the importance of recycling wastes in recent years, attempts are being made especially for incinerated ash, and only incinerated ash is pressure-molded or incinerated ash. There are already many known methods for manufacturing civil engineering and building materials using incinerated ash, such as mixing a plastic ceramic raw material and an aggregate into a mixture, press-molding, and then firing to manufacture a ceramic product such as brick.

[0003]

The ceramic products using the above-mentioned incinerated ash have a low bulk specific gravity of 0.4 to 0.6 in the incinerated ash itself when only the former incinerated ash is used. Molding pressure of typical ceramic products is 200 kg per 1 cm ^{2 of} molded product
Although it is about 300 kg, a large pressure of about 1 ton is required, so that the manufacturing facility becomes very large. In addition, the molded product has a shrinkage ratio of 15 after firing.
In addition, the incineration ash has a large variation in chemical composition depending on its natural environmental conditions and sewage treatment conditions, resulting in a large variation in the sintering temperature and poor product quality stability. I still have many problems. In addition, when the latter plastic ceramic raw materials and aggregates are added, the size and quality of the product will be stabilized, but the amount of incinerated ash will be low and it will not lead to large consumption, and reduction of raw material cost cannot be expected. . On the other hand, sand settling generated in the above-mentioned pipe dredging and sewage treatment process, pottery tube scraps generated in sand washing and sewer construction, stoneware,
Wastes such as porcelain product scraps have few uses for reuse, and most of them are currently landfilled.

[0004]

In view of the above, the present invention focuses on other wastes such as sand settling, washing sand, and ceramic shavings, and replaces the aggregate added to the incineration ash with the setting sand, washing shavings, and ceramic shavings. It provides a method for manufacturing road pavement materials using waste that enables stable quality and large-scale consumption of waste as a whole.
The structure is such that at least one kind of sand, washed sand, and ceramic waste is added to the incineration ash as an aggregate and mixed to form a kneaded clay, and after the kneaded clay is formed, the incinerated ash is sintered. It is characterized by being fired at a temperature. Further, it is desirable to add crushed and classified porcelain, stoneware and porcelain product scraps to the aggregate. Moreover, the weight part of the incineration ash is 35 to 50
%, And the weight part of the aggregate is preferably set to 45% or more. Further, as the fuel for the above-mentioned calcination, digestive gas generated in the sewage treatment process can be used.

[0005]

First, each element in the manufacturing method of the present invention will be described. "Incineration ash" Incineration ash can be used from those discharged from public sewage treatment facilities, but incineration ash has polymer type and lime type, depending on the type of coagulant added during dehydration from sewage sludge, In the present invention, a polymer incineration ash that is preferable in terms of heat consumption and firing control is used rather than a lime type that contains a large amount of CaO and has a relatively high firing temperature and a narrow softening and melting temperature range. In general, 90% of the incinerated ash has a particle size of 40 μm or less, and 50 to 60 μm in the range of 5 to 20 μm.
Since it is a fine powder in which% is concentrated, it will be treated as a fine particle raw material in the present invention hereinafter. Further, since the incinerated ash itself has poor plasticity and the strength of the molded product is not so great, an inorganic or organic binder may be added if necessary due to handling problems. Inorganic substances include kibushi clay, frog clay, bentonite, etc., and organic substances are preferably hydrophilic binders, such as starch and rubber for natural products, and CMC, PVA for semi-synthetic or synthetic products. These may be added to the incinerated ash in an amount of 5 to 15% in the case of an inorganic substance and 0.1 to 5% in the case of an organic substance. "Aggregate" This is a coarse-grain raw material that maintains its original shape at the softening and melting temperature of incinerated ash. In addition to sand components, a large amount of foreign substances such as metals and plastics are mixed in the settling sand and washing sand generated during sewage treatment, so use a magnet or a sieve. Etc. to remove as much as possible. This removal can prevent defects such as foaming and color point during firing of the molded product. The settled sand, washed sand, and porcelain waste that have been treated as described above are crushed with a sieve, classified, and if necessary, calcined to adjust the particle size of the calcined product. The particle size of the coarse particle raw material is 5.0 mm or less in the case of a water-permeable product, but 0.2-
About 3.0 mm is desirable. As other coarse particle raw materials,
Pottery, stoneware, porcelain product waste. As shown in FIG. 16, these coarse particle raw materials 2 are fine particle raw materials 3 during firing.
Even if the softened and melted material is reduced in volume, the volume of the molded product 1 as a whole is prevented, the shrinkage rate of the baked product 1'is reduced, and the pores 4
Is generated and becomes water permeable. "Burning fuel" As a fuel for firing, a digestion gas generated in a digestion tank for sewage treatment can be used. Generally, when digestion is carried out smoothly, in the case of sludge with a water content of around 97%, 350 to 550 Nl / kg of organic matter, and 7 to the sludge input.
Approximately 10 times the amount of digestive gas is generated, and the digestive gas component varies depending on the digested state of sludge, but it is approximately 60 to 65 methane.
% Vol.% Is included, and the lower heating value is 5000-5
It is 500 kcal / Nm ³ . Needless to say, these can be used as fuel not only during firing but also during drying of settling sand, washing sand, etc., during drying of kneaded clay, and during drying of molded products.

An embodiment of the present invention using the above elements will be described with reference to the drawings and tables. Example 1 A test was conducted by combining the mixing condition A and the baking condition B shown in Table 1. The incineration ash used as the raw material for the fine particles is a high-polymer type, and the clay is frog-eyed clay. As coarse particle raw material, the washed sand is dried at about 200 ° C. and classified with a sieve to 20 to 60 mesh (particle size: 0.25 to 0.84 mm), and the porcelain aggregate is crushed to 7 to 20 with a sieve. Mesh (particle size 0.84 to 2.83m
Use the one classified in m). These raw materials are mixed by stirring under four mixing conditions of the mixing condition A in Table 1, and then kneaded while adding water, granulated, and dried to obtain a kneaded clay. Next, it is molded with a hydraulic press at a pressure of 200 kgf / cm ² , and the molded product is baked in an electric furnace at four temperatures of baking conditions B shown in Table 1. The results of measuring various characteristics of the fired product are shown in FIGS.

[0007]

[Table 1]

From the results shown in FIGS. 1 and 2, those having a water permeability of 1.0 × 10 ^-2 cm / sec or more and a bending strength of 30 kgf / cm ² or more, which can be used as a road paving material, have a firing temperature in the preparation A1. B2,3, firing temperature B2, B in preparation A2
3, firing temperature B3 in preparation A3, firing temperature B3 in preparation A4. Further, it can be confirmed that the bending strength tends to increase as the firing temperature increases, and in relation to the water permeability, the ones at the firing temperatures of 1050 and 1075 ° C. show preferable values.

Example 2 In Example 1 described above, the firing conditions were combined with the mixing conditions. Here, as shown in Table 2, tests were conducted by combining the sand washing particle size conditions, the mixing conditions, and the molding conditions. As the fine particle raw material, incineration ash uses a high-polymer-type one, and clay uses frog-eyed clay. As the coarse particle raw material, the washed sand is dried at about 200 ° C. and two particle size conditions A: 7 to 20 mesh (particle size: 0.84 to 2.83 mm), 20 to 60 mesh (particle size: 0. 25 to 0.84 mm), and the porcelain aggregate is crushed and then sieved to 7 to 20 mesh.
These raw materials are prepared under four mixing conditions B, four porcelain aggregates /
Molding is performed under the sand washing ratio condition C and the three molding pressure conditions D, respectively.
The molded product is fired in an electric furnace at a firing temperature of 1075 ° C. Various characteristics of the fired product are shown in FIGS.

[0010]

[Table 2]

From the results of FIGS. 3 to 6, focusing on the characteristics as the road pavement material, the condition A1 in which the particle size of washed sand is relatively large, and the compounded condition is 40,50 parts by weight of incinerated ash B1, It is understood that B2 is preferable, and it is difficult to recognize that the condition of the porcelain aggregate / washing sand ratio particularly affects the characteristics. Further, in many cases, the molding pressure is 100, 200 kgf / cm ^2, and in the range of D1 and D2, it is possible to obtain a water permeability coefficient higher than a predetermined value.

According to the third embodiment, in the next embodiment, an experiment example was conducted in which attention was paid to the factor of the mixing ratio of the aggregate which could not be clearly confirmed in the second embodiment. That is, a combination of the compounding conditions, molding conditions and aggregate conditions shown in Table 3 is used. As the fine particle raw material, the incineration ash is a high-molecular one and the clay is a frog grain clay. The aggregates used here are sand washing, porcelain waste, and porcelain aggregates. First, wash sand about 2
Dry at 00 ° C., classify to 7-20 mesh with a sieve, shavings are dried at about 200 ° C. and crushed, then classified to 7-20 mesh with a sieve, and porcelain aggregate is crushed to Sieve 7
Use the ones classified to ~ 20 mesh respectively. These raw materials were blended under three blending conditions A, and among them, the aggregate was agitated and mixed under the aggregate blending conditions of 21 shown by triangular coordinates in FIG. 7, and then kneaded while adding water, granulated, and dried. It will be kneaded clay. Next, this kneaded material is molded by a hydraulic press under two molding pressure conditions, and the molded product is baked in an electric furnace at a baking temperature of 1075 ° C. The properties of the fired product were as shown in FIGS. In addition, here, the relationship between the aggregate mixing ratio and each characteristic is separately shown in FIG.
2-15.

[0013]

[Table 3]

Here again, paying attention to the water permeability, the incinerated ash 40 is obtained at both molding pressures of 150 and 200 kgf / cm ^2.
It was confirmed that the specified value was cleared when%, and the specified value was not cleared when the incinerated ash was 50% or more. Therefore, it can be confirmed that at least 45% or more of the aggregate is necessary. In addition, in relation to the mixing ratio, it tends to be higher as the sand washing amount ratio is higher, and is lower as the ceramic waste amount ratio is higher. However, in consideration of the bending strength as well, it is desirable that the amount of sand washed in the aggregate be 40% or less as a material that can be used as a water-permeable road pavement material.

When the incineration ash is used as the main raw material as described above, the calcined product is a coloring component contained in the incineration ash, particularly Fe.
Due to the presence of ₂ O ₃ , it exhibits a unique firing color. That is, since the color width of the product is poor for use as a road pavement material because it is yellowish brown to blackish brown, a colored upper layer portion 5 and a glaze layer 6 which are separately prepared on the surface layer portion are applied as shown in FIG. Alternatively, the three-layer structure can increase the color width.

[0016]

As described above, according to the present invention, it is possible to obtain a water permeable product having a stable quality and predetermined characteristics even when conventional incineration ash is used, and it is possible to cover most of the raw materials used with waste. As a result, a large amount of waste can be consumed. In addition to sand settling, sand washing, and ceramic shavings as aggregate, waste of stoneware and porcelain products can be reused widely, not limited to waste generated from sewage treatment and sewer construction. . In particular, when the weight part of incineration ash is set to about 35 to 50% and the weight part of aggregate is set to 45% or more, not only the water permeability but also other characteristics such as bending strength can function as a water permeable road pavement material. A suitable product that satisfies the above requirements and is excellent in shape stability and the like can be obtained. Furthermore, if the digestion gas generated in the sewage treatment process is used as the fuel during firing, it will lead to the saving of fossil fuel, which is a limited natural resource, and most of the waste generated during the sewage treatment can be reused.

[Brief description of drawings]

FIG. 1 is a table showing the results of measuring the properties of the product obtained in Example 1.

FIG. 2 is a graph showing the results of measuring the characteristics of the product obtained in Example 1.

FIG. 3 is a table showing the results of measuring the characteristics of the product obtained in Example 2.

FIG. 4 is a table showing the results of measuring the characteristics of the product obtained in Example 2.

5 is a table showing the results of measuring the characteristics of the product obtained in Example 2. FIG.

FIG. 6 is a graph showing an average value of the results of measuring the characteristics of the product obtained in Example 2.

FIG. 7 is a triangular coordinate showing the condition setting of the aggregate mixing ratio in Example 3.

8 is a table showing measurement results of bending strength of the product obtained in Example 3. FIG.

FIG. 9 is a table showing the measurement results of water permeability of the product obtained in Example 3.

FIG. 10 is a table showing the measurement results of shrinkage rate of the product obtained in Example 3.

11 is a table showing the measurement results of the bulk specific gravity of the product obtained in Example 3. FIG.

FIG. 12 is a table showing the relationship between the aggregate mixing ratio and the bending strength of the product obtained in Example 3.

FIG. 13 is a table showing the relationship between the aggregate mixing ratio and the water permeability of the product obtained in Example 3.

FIG. 14 is a table showing the relationship between the aggregate mixing ratio and the shrinkage ratio of the product obtained in Example 3.

FIG. 15 is a table showing the relationship between the aggregate ratio and bulk specific gravity of the product obtained in Example 3.

FIG. 16 is an explanatory diagram showing a state of the coarse particle raw material and the fine particle raw material of the present invention during firing.

FIG. 17 is an explanatory view showing another embodiment of the molded product of the present invention.

[Explanation of symbols]

1 ・ ・ Molded product, 1 '・ ・ Fired product, 2 ・ ・ Coarse particle raw material, 3
..Particulate raw material, 4. Porosity, 5. Colored upper layer, 6.
-Glazed layer.

Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location C02F 11/00 ZAB M

Claims (4)

[Claims] 1. At least one of sewage sludge incineration ash generated by sewage treatment, sand settling or washing sand generated by sewage treatment, and ceramic pipe scraps generated by sewer construction.
A kind of aggregate is added as an aggregate to form a kneaded clay, and after this kneaded clay is molded, a road pavement material using waste characterized by being baked at a temperature at which the sewage sludge incinerator ash softens and melts. Production method. 2. The method for producing a road pavement material using waste according to claim 1, wherein the aggregate is added with crushed and classified pottery, stoneware and porcelain product waste. 3. The method for producing a road pavement material using waste according to claim 1, wherein the incinerated ash has a weight part of 35 to 50% and the aggregate has a weight part of 45% or more. 4. The road pavement material using waste according to claim 1, wherein digestion gas generated in a sewage treatment process is used as fuel for the firing. Production method.