JP2000302492A - Cement-based composition for extrusion molding and extrusion molding product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a cement-based composition for extrusion molding capable of providing excellent extrusion moldability and/or a suitable setting time and imparting an extrusion molding product having excellent shape retention while suppressing a chlorine content. SOLUTION: This cement composition comprises burned ash of waste at least as a part of a raw material. This composition comprises a hydraulic composition containing a calcium aluminate-based mineral and/or a calcium aluminoferrite-based mineral and gypsum and has <=0.1 wt.% chlorine content (based on the total amount of cement).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a cement composition for extrusion molding, comprising a hydraulic composition produced by using incinerated ash of waste (municipal waste, sewage sludge, etc.) as at least a part of a raw material. And a cement-based extruded product using the composition.

More specifically, the present invention relates to an extruder which can provide good extrudability and / or a suitable setting time while keeping the chlorine content low, and which is excellent in shape retention. The present invention relates to a suitable cement-based composition for extrusion molding and a cement-based extruded product using the composition.

[0003]

2. Description of the Related Art As measures against general waste and industrial waste such as municipal waste and sewage sludge, which have been remarkably increasing with recent industrial and economic developments (reduction of the amount of landfill disposal), these wastes are reduced. Effective utilization and recycling are being attempted in various fields and fields. Cement containing waste (and / or its incinerated ash) as at least a part of the raw material is also expected to be a promising technique for effective utilization and recycling of such waste.

Conventionally, when waste (and / or its incinerated ash) is reused as a raw material for cement, the presence of "chlorine" contained in the waste has been an obstacle. In the waste-utilizing cement, the chlorine is used to form a hydraulic mineral (usually represented by a mineral composition of C ₁₁ A ₇ .CaCl ₂ ; C = CaO, A = Al ₂ O ₃ ), This problem is solved by making it a part of the component of cement. Such waste-based cements (having a chlorine content of about 0.5% by weight; hereinafter referred to as "standard" waste-based cements) are usually characterized by quick setting. Also, recently, "low chlorine type" waste-based cements having a chlorine content of 0.1% by weight or less have been manufactured.

[0005] On the other hand, in general, inorganic cement-based plate materials, which are one of the most promising applications (cement molded products) of cement-based materials, are widely used in the field of building materials regardless of interior and exterior. Various approaches have been taken to improve the quality and productivity of building materials and improve processes. At present, as one method of manufacturing a cement-based plate material, an extrusion molding method of extruding a predetermined cross-sectional shape by an extruder is widely used. In this extrusion molding method, in general, a molded product after extrusion molding is subjected to steam curing, autoclave curing, or the like from the viewpoint of improving productivity, and a high-strength product is manufactured.

[0006] Conventionally, generally, a molded body after extrusion is subjected to steam curing so that the strength of the molded body reaches a predetermined handleable strength. Here, from the viewpoint of improving productivity, a rapidly hardened material or a rapidly hardened cement containing a large amount of calcium aluminate (C ₃ A, ie, 3CaO.Al ₂ O ₃ ) -based mineral,
The standard waste-based cement containing about 0.5% by weight of chlorine has a setting time of less than 1 hour,
Because of its excellent initial strength, its use is being studied for the purpose of shortening the steam curing time.

[0007]

However, when a rapidly hardened material or a rapidly hardened cement containing a large amount of the calcium aluminate (C ₃ A) -based mineral is used for extrusion molding, the hardening property of the kneaded material in the molding machine is reduced by the atmosphere. It is easy to be affected by temperature, especially in summer when the temperature is high, so the curing pressure is too fast, the molding pressure becomes excessive, the surface properties of the obtained molded product may be deteriorated, and the kneaded material may be blocked in the extruder. There is. In this case, the hardness can be adjusted to some extent by adding a setting retarder to the kneaded material. However, depending on the ambient temperature, it is difficult to adjust the rate of addition of the setting retarder, resulting in a work problem. Is more likely to occur.

If the amount of calcium aluminate is too large, the cured product may expand due to its hydration, and the quality may vary, for example, the dimensional accuracy of the molded product may be reduced. Also, when the standard waste-based cement is used, similarly to the above-mentioned rapid-hardening cement, the hardness must usually be adjusted by using a setting retarder, but the hardening property is affected by the ambient temperature. Therefore, it is difficult to adjust the addition rate of the setting retarder, and it is economically disadvantageous.

On the other hand, if the hardness of the kneaded material during extrusion molding is too low, the obtained molded body will bend, making it difficult to maintain a predetermined cross-sectional shape. In other words, when the above-mentioned rapid-hardening cement or standard-type waste-based cement is used for extrusion, the initial strength is excellent and the time required for steam curing can be shortened, but the hardness of the kneaded material with respect to temperature changes and the like can be adjusted. Due to the difficulty, workability is deteriorated, and it is difficult to obtain a stable quality product.

An object of the present invention is to provide a cement composition for extrusion molding and an extruded body which have solved the above-mentioned disadvantages of the prior art.

Another object of the present invention is to provide an extruded product which can provide good extrudability and / or a suitable setting time while keeping the chlorine content low, and which is excellent in shape retention. Extrudable cementitious composition,
And an extruded product using the composition.

Yet another object of the present invention is to expand the use of waste-based cement produced from waste incineration ash.
An object of the present invention is to provide a cement-based composition for extrusion molding capable of achieving effective utilization and recycling of waste, and an extruded body using the composition.

[0013]

Means for Solving the Problems As a result of intensive studies, the present inventors have produced waste incinerated ash as a part of the raw material, and prepared a calcium aluminate-based mineral and / or a calcium aluminoferrite-based mineral and a calcium silicate. By using a hydraulic composition containing an inorganic mineral at an arbitrary ratio and keeping the chlorine content low, a good balance between the shape retention of the cement cement composition and a suitable setting time can be achieved. Have been found to be extremely effective in achieving the above object.

The cement composition for extrusion molding of the present invention is based on the above findings, and more specifically, comprises a waste incinerated ash as at least a part of a raw material; a calcium aluminate mineral, a calcium aluminoferrite mineral. A cement containing a hydraulic composition comprising at least one of them, a calcium silicate mineral, and gypsum, and having a chlorine content of 0.1% by weight (based on the total weight of the cement). It is characterized by including.

According to the present invention, furthermore, the waste incineration ash is used as at least a part of the raw material; and at least one of a calcium aluminate-based mineral and a calcium aluminoferrite-based mineral, a calcium silicate-based mineral, and gypsum. Containing a hydraulic composition having a chlorine content of 0.1% by weight
An extruded product having a hollow portion, comprising an extrusion-forming cement-based composition containing the following cement; and an internal upper side “sag” (lower portion) with respect to the shape of the hollow portion of the molding machine die of the molded product hollow portion. The cement-based extruded product has a maximum height of 0.5 mm or less when converted to a value corresponding to a hollow width of 50 to 80 mm and a flange thickness of 10 to 15 mm.

The low-chlorine-type waste-utilizing cement of the present invention can contain more calcium aluminate (C ₃ A) than ordinary portland cement, and can be produced within an extremely short time after water injection. Since it is easy to generate a fine hydrate, the kneaded material obtained using the waste-utilizing cement of the present invention can have excellent water retention while hardening to some extent at the beginning of water injection. For this reason,
When the kneaded material in such a state is extruded, it is possible to extrude the molded article under a relatively high pressure without substantially causing molding defects such as canines and undulations, and in the molded article after the extrusion molding. Can increase the ability to maintain a predetermined cross-sectional shape.

Further, the waste-based cement of the present invention can easily reduce the variation in hardness of the kneaded material due to temperature, as compared with a known rapid-hardening cement-based material.

Further, in the waste-utilizing cement of the present invention, since the calcium source (CaO) is also supplied from the waste incineration ash, the calcium source is substantially limestone (CaC).
Compared with general cement supplied from O ₃ ), it can contribute to reduction of “CO ₂ ” discharged into the environment.
In addition, in the present invention, the firing temperature during the production of clinker is usually around 1350 ° C. (1450 for general cement).
(Approximately ° C.), which also contributes to energy saving.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described more specifically with reference to the drawings as necessary. In the following description, “parts” and “%” representing quantitative ratios are based on weight unless otherwise specified.

(Cement) The waste-utilizing cement of the present invention
Contains waste incineration ash as at least part of the raw material
No. As a cement mineral composition, the composition is
Mualuminate (C _ThreeA) minerals and / or calcium
Umm alumino ferrite (C_FourAF) minerals;
Hydraulic composition consisting of uranium silicate mineral and gypsum
And a chlorine content of 0.1 weight
Contains less than% cement.

In the description of the cement mineral composition in the present invention, for example, calcium aluminate is C ₃ A (3
CaO.Al ₂ O ₃ ) and calcium aluminoferrite are expressed as C ₄ AF (4CaO.Al ₂ O ₃ .Fe ₂ O ₃ ).
For example, reference can be made to Murata Jiro et al., "Civil engineering material concrete", 2nd edition, 7th page (1996) Kyoritsu Shuppan).

(Waste) The incineration ash of waste that can be used as (at least a part of) the raw material of the waste-using cement of the present invention is not particularly limited, and general waste (domestic waste,
Etc.) and incineration ash of what is generally called "waste" such as industrial waste (including construction waste) can be used.

More specifically, for example, the incinerated ash of the waste as a raw material of the “waste-utilizing cement” of the present invention includes sewage sludge dry powder obtained by mixing quicklime with shells and sewage sludge, and other industrial wastes. Incinerated ash can be used.

The incinerated ash of these wastes may be used as it is, and if necessary, may be used as one of ordinary cement raw materials.
Raw materials obtained by adjusting the composition of waste by mixing more than one kind (eg, limestone, silica stone, aluminum ash, bauxite, iron, etc.) may be used.

As described above, by using "other raw materials" in combination with the waste incineration ash, it becomes easy to produce a cement of stable quality even when the components in the incineration ash vary.

(C ₃ A to C ₄ AF Based Minerals) The waste-utilizing cement of the present invention comprises calcium aluminate (C
₃ A) mineral, calcium alumino ferrite (C ₄ A)
F) At least one of the minerals is included. The composition may contain other aluminum compounds as required. At least a part of the aluminum source in the fired product (clinker) used in the present invention is derived from the incinerated ash of the above-mentioned waste.

The content of the calcium aluminate based mineral such as C ₃ A is 1 (based on the total weight of cement).
It is preferably 0 to 30% by weight (more preferably 15 to 25% by weight). If the content of the calcium aluminate-based mineral is less than 10% by weight, the amount of incinerated ash used is relatively small, and the effective use of waste and the effectiveness of recycling tend to decrease. On the other hand, when the content of the calcium aluminate-based mineral exceeds 30% by weight, the possibility of the cement hardened body being excessively expanded increases due to the progress of hydration of the mineral.

(Calcium silicate mineral) The waste-utilizing cement of the present invention also contains a calcium silicate mineral. At least a part of the calcium silicate-based mineral in the calcined product (clinker) used in the present invention may be derived from the above-mentioned waste incineration ash.

The calcium silicate mineral that can be used in the present invention is not particularly limited. More specifically, for example,
As the calcium silicate mineral, dicalcium silicate C ₂ S (2CaO ·
SiO ₂ ; that is, one or more of S = SiO ₂ ) and tricalcium silicate C ₃ S (3CaO · SiO ₂ ). These calcium silicate-based minerals can be used in combination of two or more as needed.

From the viewpoint of strength development, the content of the calcium silicate mineral is 50% by weight or more (based on the total weight of cement), and more preferably 50 to 80% by weight (particularly 55 to 80% by weight).
75% by weight).

(Gypsum) In the present invention, a calcined product (clinker) using the waste incinerated ash as at least a part of the raw material
The gypsum that can be added to is not particularly limited. More specifically, for example, as the gypsum, any one of anhydrous gypsum, gypsum dihydrate and hemihydrate gypsum can be used in combination of two or more as needed. It is preferable to add the gypsum in an amount of 1 to 30 parts by weight based on 100 parts by weight of the calcined product from the viewpoint of sufficiently exhibiting the strength as a molded article.

(Chlorine) The waste-utilizing cement of the present invention comprises:
Since waste incineration ash is used as at least a part of the raw material, it may contain "chlorine" contained in the waste. Even when chlorine is contained in the composition, its content is not more than 0.1% by weight (based on the total weight of the cement).

In the present invention, the above-mentioned chlorine content can be determined, for example, according to JIS R5202.

(Typical composition) From the viewpoint of improving the initial hardness of water injection and the shape retention, the waste-utilizing cement of the present invention is
10 to 30 kinds of calcium aluminate minerals
Weight percent, and 50 calcium silicate minerals
It is preferred that the content be at least 10 wt%.

Further, from the viewpoint of improving the strength and extrudability of the molded product, the waste-utilizing cement of the present invention contains 10 to 20% by weight of at least one calcium aluminate mineral and 10 to 20% by weight of calcium aluminoferrite. It is preferable that the composition contains about 20% by weight and 50% by weight or more of a calcium silicate-based mineral.

The preferred mineral composition as "clinker" in the present invention is as follows (based on the total weight of clinker components).

C ₃ S: 35 to 65% by weight (further 40 to 60% by weight) C ₂ S: 5 to 30% by weight (further 10 to 20% by weight) C ₃ A: 10 to 30% by weight (further 10-25 wt%) C ₄ AF are: 5 to 25 wt% (further 10-20% by weight) (production method of waste utilization cement) as long as it contains the aforementioned components, the waste of the present invention use The method for producing the cement is not particularly limited. More specifically, for example, the waste-utilizing cement of the present invention is obtained by calcining raw materials such as the above-described waste incineration ash at 1200 to 1500 ° C., pulverizing the obtained product (clinker), and then calcining the calcined material. It can be produced by adding gypsum to the product.

(Physical Properties of Cement) The waste-utilizing cement of the present invention produced as described above can have a larger Blaine specific surface area as compared with ordinary Portland cement. The cement can have good reactivity. Therefore, in terms of its reactivity, the specific surface area of the cement composition of the present invention,
3500 cm ² / g or more, 3500-5000c
It is preferably m ² / g.

(Starting time / Ending time) The waste-using cement of the present invention achieves a starting time close to that of ordinary cement, maintains good workability, and sets the end time within an appropriate range while maintaining the shape of the molded product. Good retention can be achieved. More specifically, the JIS R-
The starting time according to 5201-1977 (and its annex 1) is 90 minutes or more (and about 100 to 200 minutes).
It is preferred that The termination time of the composition is 360
Minutes or less (more preferably about 180 to 300 minutes).

Further, the waste-utilizing cement of the present invention can increase the content of calcium aluminate (10% by weight or more) as compared with that of ordinary Portland cement. The amount of the hydrate produced can be increased, and the hydrate is fine, so that the hydrate can be excellent in water retention. Therefore, when the low-chlorine-type waste-utilizing cement of the present invention is used, even if the extrusion pressure is high, the adhesiveness of the kneaded material is easily ensured, the extruded product is less likely to crack, and the surface properties are good. It is easy to make it difficult to deform after molding.

That is, since the fine hydrate formed in the early stage of the injection of calcium aluminate performs the same function as the clay mineral, the obtained molded article has little canine teeth (like cracks) and cracks, and A good extruded plate with small deflection can be manufactured.

The low-chlorine-type waste-utilizing cement of the present invention can exhibit the same setting properties as ordinary Portland cement. Therefore, it is a rapidly hardening material containing more calcium aluminate minerals in the cement. Compared to the case of using a rapidly hardening cement-based material such as cement or standard waste-based cement, it is possible to stably supply a kneaded material having a hardness suitable for extrusion molding regardless of the temperature of the kneaded material. In addition, there is no possibility that the pressure of the extruder is excessively increased or the extruder is clogged, and the variation in product quality can be reduced.

(Other Components) The waste-utilizing cement of the present invention contains at least one of the above-described calcium aluminate-based minerals and calcium alumino-ferrite-based minerals, a calcium silicate-based mineral, and gypsum.
If necessary, other components may be contained. Such “other components” include, for example, reinforcing fibers, thickening aids, and the like.

(Reinforcing Fibers) The cement composition for extrusion molding of the present invention may contain reinforcing fibers, if necessary. As the reinforcing fibers, known fibers made of organic fibers such as asbestos, pulp, polypropylene, polyethylene, vinylon, aramid, polyester, carbon, cotton linter, fibers obtained by cutting used paper such as corrugated cardboard and newspaper, and inorganic fibers such as rock wool. Can be used alone or in combination of two or more as necessary.

The content of the reinforcing fiber is 2 parts by weight based on the whole composition (including the reinforcing fiber itself) (100 parts by weight).
It is preferably 0 parts by weight or less (more preferably 15 parts by weight or less). When the content of the reinforcing fiber exceeds 20 parts by weight, the water absorption of the extruded molded article increases, and the possibility of causing problems in durability such as bending strength and frost damage resistance increases.

(Thickening aid) The thickening aid (or extrusion aid) optionally contained in the cementitious composition for extrusion molding of the present invention may be any known thickening aid without particular limitation. It is possible to use. As such a thickening aid,
For example, water-soluble polymer substances of cellulose derivatives such as methylcellulose and hydroxyethylcellulose can be used alone or in combination of two or more as needed.

The content of the thickening aid is 3 parts by weight with respect to the whole composition (including the thickening aid itself) (100 parts by weight).
It is preferable that the amount is not more than about 10 parts by weight (more preferably about 0.2 to 2 parts by weight).

(Composition at the time of use) When the cement composition for extrusion molding of the present invention is actually used, for example, when it is used for extrusion molding, the following cement composition is used. preferable.

The above cement: 30 to 70 parts by weight (further 40 to 60 parts by weight) Silicic powder: 20 to 50 parts by weight (further 20 to 40 parts by weight) Fiber: 2 to 20 parts by weight (furthermore 2 to 20 parts by weight) 15 parts by weight) Organic thickener: 0.2 to 2.0 parts by weight (further 0.2 to 2.0 parts by weight)
(1.5 parts by weight) (Method of use) The above-mentioned cementitious composition for extrusion molding of the present invention has excellent extrusion performance, and provides an extruded body having excellent surface smoothness and excellent shape retention of hollow portions. Taking advantage of
The present invention can be particularly suitably used for extrusion molding (especially, an embodiment in which an extruded body having a hollow portion is formed).

(Extrusion Molding Method) The cement composition for extrusion molding of the present invention can be formed into an extruded product through the same steps as in the prior art. In a typical embodiment of such extrusion molding, for example, dry blending using a forced stirrer or the like, wet blending by adding an appropriate amount of water to the obtained blend, and then, for example, double-arm kneading Kneading is performed using a machine. Thereafter, the obtained kneaded material is guided to a vacuum extruder having a desired mold, and extruded under pressure. The extruded compact is cured under desired conditions (steam curing, autoclave curing, or a combination thereof).

(Extruded product) The extruded product of the present invention is prepared by using the above-mentioned cement composition (the cement composition of the present invention).
And an extruded body having a hollow portion. The maximum height of the "sag" (projecting downward) on the inner upper side with respect to the shape of the hollow portion of the molding machine die of the hollow portion of the extruded product of the present invention is 50 to 80 mm in hollow width and 10 to 15 m in flange thickness.
It is 0.5 mm or less when converted to a value for m. The maximum height of the “sag” is particularly preferably 0.2 mm or less. The schematic sectional view of FIG. 1 shows various dimensions (panel thickness A, flange thickness B, rib thickness C,
And the definition of the hollow width D).

The extruded product has the above-mentioned predetermined shape (hollow width: 50 to 80 mm, flange thickness: 10 to 15 mm)
In the case of having a shape / size other than the above, for example, by computer simulation, the value of “sag” in the “other shape / size” may be converted to the value of “sag” of the above-mentioned predetermined shape. It is possible.

The cement composition for extrusion molding of the present invention comprises:
Depending on the temperature, the setting speed may be different. As described above, even when the setting speed is different depending on the temperature, the maximum height Ha (mm) of the inside upper portion “sag” of the molded body hollow portion at 20 ° C. and the molded body hollow portion at 30 ° C. Height Hb of the upper part of the sauce
(Mm), the ratio Ha / Hb is preferably 5 or less, more preferably 4 or less.

The maximum height of the “sag” on the inner upper side can be suitably measured by a measuring method described later.

(Various physical properties)
It preferably has the following physical properties when measured by the measurement method described below.

<Molded Product> Water absorption: less than 18% (more preferably less than 15) Molding pressure: 20 kgf / cm ² or less (furthermore, 18 kgf
/ Cm ² or less) Bending strength: 18N / mm ² or more (even 20 N / mm ² or more) or less, examples, a more detailed explanation of the present invention Comparative Examples, which are located in the illustrated limit the present invention It does not do.

The raw materials used in the examples and comparative examples, the method for preparing the test pieces, and the methods for measuring various physical properties of the cured products are as follows.

(Measurement method) Maximum height of “sag” After extrusion molding , the maximum height of the “sag” (projecting downward) inside the hollow portion of the molded product was measured using a Canon caliper (manufactured by Nakamura Seisakusho). Measured. The “hollow part” to be measured is
A hollow portion at the center of the molded body and a second hollow portion from both ends were formed. The measurement point was the center of the hollow part to be measured. (See FIG. 4) <Calculation formula> The height of the hollow portion of the die (of the extrusion molding machine) is P
(Mm), and when the height of the hollow portion of the molded body was Q (mm), the “sag” R (mm) of the hollow portion was determined by the following equation. Since there are a total of three measurement points for one extruded product, these three data are obtained. The maximum value of these three values was taken as the maximum height of “sag”.

R = PQ (unit: mm) Chemical composition The measurement was carried out in accordance with JIS-R-5202 "Chemical analysis method of Portland cement".

The water absorption was measured in accordance with JIS-A-5430 “Fiber-reinforced cement board 5. Test 5.7 Water absorption test”.

The molding pressure was measured by a pressure gauge (manufactured by Tokyo Sokki Laboratory Co., Ltd.) mounted near the mouth of the extrusion molding machine.

The flexural strength was measured in accordance with JIS-A-5430 “Fiber-reinforced cement board 5. Test 5.5 Bending test”.

Example A low-chlorine-type waste-utilizing cement of the present invention was produced by the following method.

First, dried municipal waste incineration ash having the chemical composition shown in Table 1 below was used as a raw material.

These two types of municipal garbage incineration ash were blended in the two ratios (type-1 and type-2) shown in Table 2 to obtain a blended raw material. These prepared raw materials (two types) were each fired at 1300 to 1450 ° C. using a rotary kiln to obtain clinker. Table 3 shows the chemical composition of the obtained clinker, and Table 4 shows the mineral composition.

[0066]

[Table 1]

[0067]

[Table 2]

[0068]

[Table 3]

[0069]

[Table 4]

The cement obtained by pulverizing the obtained clinker and adding gypsum at the ratios shown in Table 5 had a Blaine specific surface area corresponding to the prepared raw material type-1 of 4200 c.
m ² / g, those corresponding to the formulation material type-2 4500
cm ² / g.

[0071]

[Table 5]

The two types obtained above (type-1 and ty
Other materials were kneaded with the low-chlorine waste cement of pe-2) in the mixing ratios shown in Tables 6 and 7 below. The materials used at this time were as follows.

Silica powder: Chichibu Mining Co., Ltd. Fibrous material: Mikata Shoko Co., Ltd., pulverized pulp Thickener: Shin-Etsu Chemical Co., Ltd., water-soluble cellulose Asbestos: KCAC Co., Ltd. Wollastonite: Tomoe Kogyo Co., Ltd. Reinforcement fiber: Tezak Co., Ltd. The outline of a method for producing a cementitious composition for extrusion molding and an extruded product is shown in a flowchart of FIG. Referring to the flow chart of FIG. 2, each raw material other than the above-mentioned water, that is, cement, silica powder, pulp, asbestos, and a thickener (extrusion aid) are blended as shown in Tables 6 and 7 below. After dry-mixing (primary mixing) for 1 minute using a forced agitator (Nippon Eirich Co., Eirich mixer),
To the resulting mixture, water was added in the amounts shown in Tables 6 and 7, and further wet-mixed with the forced agitator for 3 minutes.

[0074]

[Table 6]

[0075]

[Table 7]

Next, kneading was performed for 6 minutes using a double-arm kneader (manufactured by Mikami Kogyo KK). After confirming that the obtained kneaded material has a hardness of 11.5 ± 0.5 by a hardness measurement method described later, the kneaded material is subjected to a small vacuum extruder (opening width 40 mm).
mm × 10 mm in thickness, manufactured by Honda Iron Works Co., Ltd.), and extruded to produce a molded body having a width of 40 × about 160 mm.

Next, the molded body obtained as described above was cured. This curing is steam curing (60 ° C x 6 hours)
After that, autoclaving (175 ° C. × 5 hours) was further performed.

At this time, the molding pressure generated near the die,
The amount of deflection when the molded body was allowed to stand for 24 hours after molding and the bending strength after autoclaving was measured, and the surface of the molded body was observed.

The “deflection amount” was measured as follows.

<Measurement Method of Deflection Amount> A "deflection measuring device" as shown in a schematic perspective view in FIG. 3 was used. The pedestal portion of this deflection measuring instrument was made of iron, the two rollers were made of iron having a diameter of 5 mm, and the support interval between the formed bodies was 150 mm.

Immediately after molding, the compact was gently placed on the deflection measuring instrument, and allowed to stand for 24 hours in an environment at a temperature of 20 ° C. and a humidity of 60% RH. After the standing, the maximum portion (near the center) of the molded article "deflection" was measured with a vernier caliper, and was defined as "the amount of deflection".

Further, a molded article having a width of 28 cm × a thickness of 5 cm × a length of about 120 cm was produced by extrusion using a medium-sized vacuum extrusion molding machine (made by Mikami Kogyo Co., Ltd .; opening width 280 mm × thickness 50 mm). , Observation of “sagging” of the hollow portion, and measurement of the maximum height thereof. FIG. 4 shows a schematic sectional view of the obtained extruded product. In the molded body shown in FIG. 4, the overall panel thickness A was 50 mm, the flange thickness B was 10 mm, the rib thickness C was 12 mm, and the hollow width D was 62 mm. The results of the extrusion molding test are shown in Tables 8 and 9.

As a comparative example, a standard waste cement, an ordinary Portland cement manufactured by Taiheiyo Cement Co.,
Rapid hardening cement (Pacific Ocean Cement Co., Ltd. jet cement), Blaine specific surface area of 3000cm ² / g, and 6000cm ² / g low-chlorine-type waste using cement type of
The same test was conducted using -1.

The results of the extrusion molding test of each cement are shown in Tables 8 and 9.

[0085]

[Table 8]

[0086]

[Table 9]

Among the evaluation items shown in Tables 8 and 9, "moldability" and "hollow sagging" were evaluated as follows.

[0088] moldability ○: canines (like crack) if there is no molding defects such as Yahibiware △: it is no practical problem level, but if the canines (like crack) Yahibiware like there is little ×: practical problem If there are a lot of canines (like cracks) or cracks, etc. Small droop in the hollow part : If you do not know even if you touch the deflection (the value of "sag" is 0 to 0.5 mm) Medium: If you can touch the deflection a little ( Large: When the deflection is clearly noticeable by touching (the numerical value of “sag” is 1.0 mm or more). From Tables 8 and 9, the use and non-use of asbestos are shown. Regardless, when the low-chlorine waste-based cement of the present invention is used, the molding pressure is slightly increased as compared with the case where ordinary Portland cement is used, but the surface properties of the molded body are equal to or better than those of the ordinary case. there were. On the other hand, since the amount of deflection is small, it can be easily understood that the low-chlorine-type waste-utilizing cement of the present invention is excellent in maintaining the cross-sectional shape.

Among the comparative examples, the Blaine specific surface area was 30
In case of using 00Cm ² / g and 6000cm low chlorine type waste was ² / g available cement type-1 (Comparative Examples 6 and 7), ordinary Portland cement equivalent amount of deflection is obtained. In the molded article, several canine parts (at practically no problem) were observed.

In the case where the low-chlorine waste-utilizing cement type-2 was used (Example 6), the amount of deflection was smaller than that of the ordinary Portland cement (Comparative Example 4), and the effect of maintaining the cross-sectional shape was good. Furthermore, the molding pressure was smaller than when the above-mentioned type-1 was used, and the surface properties of the molded product were further excellent.

When the standard waste-based cement (Comparative Examples 1 to 3) was used, the molding pressure in the vicinity of the die was extremely increased at kneading temperatures of 20 ° C. and 30 ° C. Was observed, and at 30 ° C., the kneaded material was blocked in the extruder. Here, molding is possible by increasing the rate of addition of the setting retarder used at the time of kneading, but it is not preferable from the economical point of view, and it is difficult to adjust the hardness due to a large change in hardness due to the ambient temperature.

The setting retarder was also added in the example using the rapid-hardening cement containing a large amount of calcium aluminate-based mineral (Comparative Example 5), but the addition rate was adjusted for the same reason as in the standard waste cement. Although difficult, the deflection after extrusion was very small, the molding pressure was extremely increased and the surface properties were not good.

Tables 10 to 12 below show the chemical compositions, mineral compositions, and setting results of the various cements used in the above-mentioned Examples and Comparative Examples.

[0094]

[Table 10]

[0095]

[Table 11]

[0096]

[Table 12]

[0097]

As described above, according to the present invention, the cement composition for extrusion molding is based on the above findings,
More specifically, waste incineration ash is used as at least a part of the raw material; and a hydraulic composition comprising at least one of calcium aluminate-based mineral and calcium alumino-ferrite-based mineral, calcium silicate-based mineral, and gypsum is used. A cement containing 0.1% chlorine.
There is provided a cementitious composition for extrusion comprising up to 1% by weight (based on the total weight of the cement) of cement.

According to the present invention, furthermore, waste incineration ash is used as at least a part of the raw material; from at least one of calcium aluminate-based mineral and calcium aluminoferrite-based mineral, calcium silicate-based mineral, and gypsum. Containing a hydraulic composition having a chlorine content of 0.1% by weight
An extruded body having a hollow portion, comprising an extruded cementitious composition containing the following cement; and "sag" (a downwardly protruding portion) on the upper inside side of the hollow portion of the formed body.
Has a maximum height of 50 to 80 mm and a flange thickness of 1.
There is provided a cement-based extruded product having a value of 0.5 mm or less when converted to a value for 0 to 15 mm.

The cement-based composition for extrusion molding of the present invention comprises:
Since it is hardly affected by changes in the ambient temperature, it is easy to produce a product with stable quality even when extrusion molding is performed continuously. In addition, the molded article has good surface properties even when extruded at a relatively high pressure, and can have excellent cross-sectional shape retention performance.

The waste-utilizing cement of the present invention has a low chlorine content that allows a certain amount of hydrate to be formed within an extremely short period of time after kneading with water, and gives a setting time almost equal to that of ordinary Portland cement. Since this is a cement utilizing mold waste, by using it for extrusion molding, a molded article having good surface properties after extrusion and excellent in maintaining the cross-sectional shape can be easily obtained.

Further, the cement composition for extrusion molding of the present invention is useful for effectively utilizing and recycling waste such as municipal garbage incineration ash and sewage sludge incineration ash, which are the raw materials of cement in the cement composition. Can contribute.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view showing the definition of dimensions of each part in an extruded body having a hollow part.

FIG. 2 is a flowchart showing the steps of manufacturing an extrusion-molded cementitious composition and an extruded body manufactured in Examples.

FIG. 3 is a schematic perspective view showing a configuration of a “deflection amount measuring device” used in the embodiment.

FIG. 4 is a schematic cross-sectional view showing measurement points of “sag” in a hollow portion of a molded body after extrusion molding obtained in an example.

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) C04B 28/02 B09B 3/00 301M // (C04B 28/02 7:28 22:14) 111: 00 (72) Invention Toyoyuki Kubokawa 1-2-23 Kiyosumi Research Institute, Koto-ku, Tokyo (72) Inventor Shinya Kikuchi 1-2-23 Kiyosumi Research Institute, Koto-ku, Tokyo F-term in Kiyosumi Research Institute, Pacific Cement Co., Ltd. Reference) 4D004 AA36 BA02 CA45 CC03 CC13 DA03 DA10 4G012 PA04 PA24 PA34 PD01 PE04 PE06 4G054 AA01 AA15 AB07 AC00 BD03

Claims (9)

[Claims] 1. A hydraulic composition comprising at least part of a waste incinerated ash as a raw material; at least one or more of a calcium aluminate-based mineral and a calcium aluminoferrite-based mineral, a calcium silicate-based mineral, and gypsum. And a chlorine content of 0.1% by weight (based on the total weight of the cement)
A cement composition for extrusion molding, comprising the following cement. 2. The extrusion-based cement-based composition according to claim 1, wherein in a setting test of the cement according to JIS R5201, the starting time is 90 minutes or more and the finishing time is 360 minutes or less. 3. The extrusion-based cement composition according to claim 1, wherein the incineration ash of the waste is at least one incineration ash selected from municipal waste incineration ash and sewage sludge incineration ash. 4. The hydraulic composition according to claim 1, wherein the hydraulic composition contains 10 to 30% by weight of at least one calcium aluminate-based mineral and 50% by weight or more of a calcium silicate-based mineral. Cementitious composition for extrusion molding. 5. The hydraulic composition contains 10 to 20% by weight of one or more of calcium aluminate-based minerals, 10 to 20% by weight of a calcium aluminoferrite-based mineral, and 50% by weight of a calcium silicate-based mineral. The cement composition for extrusion molding according to any one of claims 1 to 3, which comprises the above. 6. The cement according to claim 3, wherein said cement has a Blaine specific surface area of 3
The cement composition for extrusion molding according to any one of claims 1 to 5, wherein the composition is 500 to 5000 cm ² / g. 7. The cement of 30 to 70 parts by weight, further contains 20 to 50 parts by weight of siliceous powder and 2 to 2 fibers.
The cement composition for extrusion molding according to any one of claims 1 to 6, wherein 0 parts by weight and 0.2 to 2.0 parts by weight of an organic thickener are added. 8. A hydraulic composition comprising at least a part of a waste incinerated ash as a raw material; and at least one of a calcium aluminate-based mineral and a calcium aluminoferrite-based mineral, a calcium silicate-based mineral, and gypsum. An extruded body having a hollow portion, comprising a cement-based composition for extrusion molding containing a cement having a chlorine content of 0.1% by weight or less; and a molding machine die for the hollow portion of the formed body. The maximum height of the internal upper portion "sag" (projecting downward) with respect to the hollow shape is 0.5 mm or less when converted to a value for hollow width 50 to 80 mm x flange thickness 10 to 15 mm. Characterized cement-based extrudate. 9. A maximum height Ha (mm) of an inner upper portion “sag” of the hollow body at 20 ° C. and a maximum height Hb of an inner upper portion “sag” of the hollow body at 30 ° C. The ratio Ha / Hb to (mm) is 5 or less.
The cement-based extrudate according to the above.