JP3440293B2 - Foam using incinerated ash slag glass - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to incineration ash (hereinafter referred to as "garbage incineration ash"), which is generated in large amounts by incineration of sewage sludge and municipal waste.
Called. The present invention relates to a foam material obtained by effectively using slag glass obtained by vitrifying

[0002]

2. Description of the Related Art A large amount of refuse incinerated ash is generated in many cities and is generally disposed of by burying it in the ground. However, due to the shortage of disposal sites, it is desirable to reduce the volume. ing. In addition, the effective use and reuse of resources, which have been prosperous in recent years,
Alternatively, in order to prevent environmental pollution, it is necessary to reduce the absolute amount of these refuse incineration ash.

Conventionally, in order to reuse the refuse incineration ash, reduction and melting of the refuse incineration ash to form a slag glass has been promoted, and a foam material that can be effectively used as a building material or the like is produced from a crushed product of the slag glass. Attempts are being made.

That is, a crushed product of slag glass produced from waste incineration ash, clay and, if necessary, an additive that promotes foaming are mixed, and water is added and kneaded to obtain a kneaded product of 800 ° C. or higher. When fired in the temperature range of, the foaming begins in the firing process due to the release of the gas substances contained and the gas components accompanying the redox reaction, and further the promotion of softening of the glass phase under high temperature conditions The foaming amount of the lever increases rapidly, and a foam material is obtained. This foam material is useful as a lightweight soundproofing material, a heat insulating material or the like utilizing the cell structure.

[0005]

However, when the mixture of crushed slag glass and clay is fired and foamed as described above, the foaming amount greatly differs depending on the case, and the desired foaming amount, that is, the desired specific gravity is obtained. In addition, there is a problem that a foam material having a porosity cannot be stably manufactured.

This is because the composition of sludge and municipal waste, which are the raw materials of slag glass, is not constant, and the composition of slag glass also greatly differs depending on the place of occurrence, the time of occurrence, etc. This is because the temperature and the softening temperature range of the glass are greatly different, and the timing of softening the glass after foaming is deviated.

For this reason, a foam material having a good foaming property can obtain a foam material having a volume two times or more that of the volume before firing, but a foam material having a remarkably small expansion ratio of 1.5 times or less before firing. In many cases, it is formed, and the desired foam material cannot be industrially stably produced.

An object of the present invention is to solve the above conventional problems and provide a foam material having a stable foaming amount.

[0009]

The foam material using the incinerated ash slag glass of the present invention is a mixture of crushed slag glass obtained by vitrifying refuse incinerated ash and clay, and firing the resulting mixture. In the foamed material obtained in this way, sodium carbonate was added to the mixture, and the mixture was added to the crushed slag glass in an amount of 0.
A foam material containing 5 to 10.0% by weight of the slag
Sum of sodium carbonate and clay for ground glass
Is 15.0 to 30.0% by weight .

The foaming reaction mechanism by firing the mixture of slag glass and clay is as follows.

The slag glass produced from refuse incineration ash basically contains many fine particles of iron oxide (FeO) inside the produced glass because of its melting in a reduced state.

When such a material is heated, the reaction of 2FeO → 2Fe + O ₂ is promoted in a high temperature state (Fe dissolves in the glass at a higher temperature), and oxygen gas is surrounded by minute particles inside the glass. Many bubbles are formed.

The slag glass begins to soften at a high temperature of 850 ° C. or higher and its viscosity rapidly decreases with increasing temperature. Therefore, the size of these bubbles rapidly increases with decreasing glass viscosity. To do. When it reaches the temperature range of 950 to 1050 ° C., the viscosity of the glass sharply decreases, so that the bubbles expand and become continuous bubbles (space).

Under such high temperature conditions, the mixed clay forms metakaolin by dehydration reaction at several 100 ° C., but under higher temperature conditions, it reacts with the slag glass phase and wollastonite (CaSiO ₃ ). And quasi-feldspar (CaAlS
i ₂ O ₇ ) or anorthite (CaAl ₂ Si ₂ O ₈ ) is formed.

These form the wall surface of continuous bubbles,
Further, it forms a three-dimensional network structure, but these skeletons maintain the strength of the final product and add functions to the product.

Then, up to this stage, a foam material in which continuous bubbles are present with an equal particle size distribution is formed.

From the above, the composition of the slag glass has a great influence on the foaming reaction, but as described above, the composition of the slag glass is the composition of waste incineration ash, that is, the composition of incinerated sludge and municipal waste. However, in the past, it was not possible to obtain a foam material with a stable foaming amount.

In contrast, according to the present invention, sodium carbonate
By adding strontium (Na ₂ CO ₃ ), practically soda ash, it is possible to significantly increase the foaming amount and stabilize the foaming amount.

That is, for example, soda ash can promote the increase of the sodium component in the foaming raw material and can greatly reduce the viscosity of the slag glass under high temperature conditions. Compared with the additive-free one, the softening of the glass can be greatly promoted.
For this reason, the bubbles generated in the process of firing at 800 ° C. or higher rapidly expand at around 900 ° C. with the softening of the glass phase, and finally become an aggregate of continuous bubbles in which individual bubbles are connected, A foam material having a high foaming amount is formed.

Sodium carbonate is 0.5 to 10.0% by weight, preferably 3.0 to 1 based on the slag glass pulverized product.
0.0 wt%, more preferably 3.0 to 5.0 wt%, so that the total ratio of clay to crushed slag glass is 15.0 to 30.0 wt%
It

The maximum temperature for firing is 950 to 1050.
It is preferable to carry out at ° C.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail in accordance with the procedure for producing a foam material of the present invention.
The following manufacturing method is an example of the method for manufacturing the foamed material of the present invention, and the foamed material of the present invention is not limited to that manufactured by the following manufacturing method.

To produce the foamed material of the present invention, first, slag glass is crushed, and a crushed slag glass material (hereinafter sometimes simply referred to as "slag glass") is mixed with clay.

The slag glass used in the present invention is produced by reduction melting of refuse incineration ash, and this slag glass is crushed to a particle size of 1.5 mm or less before use.
If the crushed particle size of the slag glass is too large, the mixing workability is poor and it becomes difficult to obtain a uniform mixture of foaming raw materials.
If the particle size of the slag glass is too small, the foamability will deteriorate. Generally, the particle size range of the raw slag glass is 74-1.
It is preferably 500 μm, and particularly preferably 250 to 1500 μm.

The clay mixed with the slag glass is not particularly limited. That is, in the present invention, the composition and quality of the clay used has almost no influence on the foamability, so that any clay can be used under the same conditions.

The mixing ratio of clay is such that the total weight of the below-mentioned sodium carbonate and clay is 15.0 with respect to the slag glass.
30.0 shall be the amount such that the weight%. When the proportion of clay is less than the above range, the strength required for the foam material cannot be obtained, and when it is large, a foam material having a large foaming amount cannot be obtained.

Then, in a mixture of slag glass and clay
Add sodium carbonate and stir to mix evenly.

If the amount of sodium carbonate added is too large, precipitation of sodium carbonate will occur around the foam material after firing, and the amount of clay added will be relatively reduced, so that the strength required for the foam material can be obtained. It will be difficult. On the contrary, if the addition amount of sodium carbonate is small, the effect of improving the foamability cannot be obtained. Therefore, sodium carbonate is 0.5 to 10.0% by weight, preferably 3.0 to 10.
0 wt%, more preferably added in a range of 3.0 to 5.0 wt%.

The present invention is characterized in that the same amount of foaming can be obtained by uniformly mixing the raw materials regardless of the type of slag glass, that is, the foamability.
The addition amount of the soda ash can be made substantially constant regardless of the type of slag glass used.

Carbonic acid such as slag glass, clay and soda ash
After mixing sodium , water is added to this and kneading is performed. The amount of water added is generally 10.0-2 based on the weight of the mixture of slag glass, clay and sodium carbonate.
It is set to about 0.0% by weight.

Next, the kneaded product is cast into a mold of an appropriate size to be molded, and then placed in a baking furnace and baked. In this molding, the type and material of the mold, the shape, the pressure during molding, etc. do not significantly affect the foamability, so any conditions can be adopted. Further, as the firing conditions, the heating rate is preferably slower from the viewpoint of promoting softening of the glass and promoting foaming that occurs at the same time, and is determined in consideration of the composition and production efficiency of the slag glass used, Usually, 10 to 20 ° C./minute is preferable. The maximum firing temperature is preferably 950 to 1050 ° C. If this temperature is lower than 950 ° C, foaming does not proceed sufficiently, and if it exceeds 1050 ° C, high-temperature oxidation occurs and the color changes to brown, and the foaming material itself begins to soften. Further, in order to prevent cooling cracks after firing, it is preferable to perform cooling after firing at a temperature lowering rate of about 5 to 50 ° C./min so that rapid cooling does not occur. The firing furnace used is not particularly limited as long as it can fire under the above firing conditions, and its type is not particularly limited. The heating method may be either electric or gas.

The foam material using the slag glass of the present invention thus obtained is generally about 3.0 to 5.0% by weight of soda regardless of the type of slag glass. By adding ash, a foaming ratio of 2.0 to 3.9 times (ratio of the volume after firing to the volume before firing) can be stably obtained. Therefore, a practical foam material can be easily produced in industrial production. It becomes possible to do.

[0033]

EXAMPLES The present invention will be described more specifically below with reference to experimental examples, examples and comparative examples.

Experimental Example 1 Using slag glass evaluated to have poor foamability,
The relationship between particle size and foamability was investigated.

First, slag glass having a particle size distribution shown in Table 1 was used, slag glass and clay (Kibushi clay) were mixed in the ratio shown in Table 1, and soda ash was further mixed with the mixture to obtain a mixture. Water was added to and kneaded. This kneaded product was put into a mold to be molded, and thereafter, it was baked at a temperature rising rate of 10 ° C./minute, a high temperature baking temperature of 950 ° C. for 15 minutes, and a temperature decreasing rate of 10 ° C./minute.

The expansion ratio of the obtained foamed material was examined, and the results are shown in Table 1.

It can be seen from Table 1 that the slag glass has poor foamability when there are many fine particles, and therefore it is preferable to classify the fine particles in order to obtain a foam material having a large expansion ratio.

[0038]

[Table 1]

Examples 1 to 7, Comparative Example 1 Slag glass similar to that used in Experimental Example 1 (particle size range 50
0 μm or less) and clay were used to produce a foam material in the same manner as in Experimental Example 1 except that the soda ash addition rate shown in Table 2 was mixed, and the expansion ratio thereof was examined. The results are shown in Table 2.

From Table 2, it can be seen that the addition of soda ash markedly increases the expansion ratio and stabilizes the expansion amount. Further, when considering the improvement of the expansion ratio and the addition cost of soda ash, it is understood that the addition amount of soda ash is preferably 3.0 to 10.0% by weight with respect to the slag glass.

[0041]

[Table 2]

Example 8 and Comparative Example 2 Slag glasses A to D having different compositions (particle size range: 500 μm)
The following) was used to mix with soda ash in the following formula I (soda ash addition ratio to slag glass was 3% by weight), and in the comparative example without soda ash, the following formula II was mixed. A foam material was manufactured in the same manner as in Experimental Example 1 except that the above was performed.

[0043]

The expansion ratio of the obtained foamed material was examined, and the results are shown in Table 3.

[0045]

[Table 3]

From Table 3, it can be seen that by adding soda ash, the expansion ratio can be stabilized in the range of 3 to 4 times with a uniform mixture for all slag glasses.

[0047]

As described in detail above, according to the present invention, the slag glass of incinerated ash of sludge or municipal waste whose composition and conditions are greatly changed has uniform continuous cells and a stable foaming amount. It is possible to obtain a material, which can reduce the volume and effectively reuse the waste. The foam material of the present invention, by easily adjusting the size of the cells,
As a sound absorbing material with soundproofing effect, heat insulating material, etc.
As residential or industrial building materials or construction materials, filling materials, etc.
Very useful for a wide range of applications.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Satoshi Honda 3-5-11 Doshomachi, Chuo-ku, Osaka-shi, Osaka, Japan Nippon Sheet Glass Co., Ltd. (56) Reference JP-A-8-26844 (JP, A) Kaihei 6-87677 (JP, A) JP 9-110549 (JP, A) JP 48-60114 (JP, A) JP 56-96767 (JP, A) Sakuo Sakuo and 2 others Volume "Glass Handbook" August 1, 1981, published by Asakura Shoten Co., Ltd. 287.288 pages (58) Fields investigated (Int.Cl. ⁷ , DB name) C04B 38/00-38/10

Claims (3)

(57) [Claims] 1. A slurry obtained by vitrifying refuse incineration ash.
The ground glass is mixed with clay and the resulting mixture is mixed.
In the foam material obtained by firing, Sodium carbonate to the mixtureFor slag glass crushed products
On the other hand, it is a foam material added with 0.5-10.0% by weight.
hand, Sodium carbonate and clay for crushed slag glass
And the total ratio is 15.0 to 30.0% by weight. thing
A foam material using incinerated ash slag glass. 2. The method of claim 1] Oite to claim 1, the maximum temperature 950-1
A foam material using incinerated ash slag glass, which is fired at 050 ° C. 3. The method of claim 1 or 2, foam with ash slag glass, characterized in that the expansion ratio represented by the fired volume to the pre-firing volume is more than 2 times.