JP2001089204A - Binder for inorganic material and cement composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a binder for an inorganic material, which is controlled in the solubility of calcium ion and aluminum ion to water, and a cement composition capable of obtaining a hardened body excellent in dimensional stability and durability, and having high hardening speed. SOLUTION: The binder for the inorganic material is composed of a mixture of activated powder obtained by applying 0.5-30 kwh/kg mechanical energy to aluminum hydrate having a porous structure having 0.01-1.0 cm3/g porosity with a calcium compound and the cement composition is prepared by containing the binder for the inorganic material and cement.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a binder for inorganic materials in which the solubility of calcium ions and aluminum ions in water is optimally controlled, and to provide a cured product having excellent durability and dimensional stability, and The present invention relates to a cement composition having a high setting speed.

[0002]

2. Description of the Related Art When a construction is performed using cement, a cement having a high curing speed is desired in order to shorten the construction period and urgent construction. Further, in a factory that manufactures industrial products using cement, a cement having a high curing speed is desired in order to shorten a period until shipment and to simplify curing equipment and curing equipment. Conventionally, as a fast setting cement having a high setting speed, an ultra-fast setting cement is conventionally known.This cement is commercially available from Chichibu Onoda Co., Ltd. under the trade name of jet cement, for example, and the setting speed is increased by forming ettringite at an early stage. (Japanese Patent Laid-Open No. 47
-34519).

However, this ettringite has a swelling property at the time of formation, water of crystallization in ettringite desorbs at a lower temperature than water of crystallization of ordinary cement hydrate, and reacts with unhydrated calcium aluminate. And changes to a monosulfate hydrate having low strength. Therefore, the cured cement containing ettringite has problems in durability and dimensional stability. As a cement which does not form ettringite but has a high curing speed,
Japanese Patent Publication No. 0-182203 discloses a cement in which a powder obtained by adding mechanical energy to an aluminum compound having water of crystallization and an inorganic powder composed of a calcium compound having water of crystallization are added.

However, it is necessary to apply a relatively large amount of mechanical energy to produce the powder described in the above-mentioned publication, and this is not always a satisfactory method in terms of productivity.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems relating to the conventional cements and the like. An object of the present invention is to provide a binder for an inorganic material in which solubility of aluminum ions in water is controlled, and a cement composition.

[0005]

According to the present invention, there is provided a powder obtained from aluminum hydrate having a porous structure having a porosity of 0.01 to 1 CC / g. A binder for an inorganic material, comprising a mixture of an active powder obtained by applying mechanical energy of 1 kWh / kg and a calcium compound.

According to the present invention, the powder obtained from the aluminum hydrate having the porous structure is obtained by subjecting the aluminum hydrate to a heat treatment in a temperature range of 200 to 600 ° C. The binder for an inorganic material according to claim 1, which is obtained.

According to a third aspect of the present invention, the aluminum hydrate is gypsite.
Or the binder for inorganic material according to 2.

According to a fourth aspect of the present invention, there is provided the binder for inorganic material according to any one of the first to third aspects, wherein the calcium compound is calcium hydroxide or calcium oxide. According to a fifth aspect of the present invention, there is provided a cement composition comprising a cement and the binder for an inorganic material according to any one of the first to fourth aspects.

In the present invention, the above-mentioned aluminum hydrate is not particularly limited as long as it has water of crystallization, and examples thereof include aluminum hydroxide (gypsite, bayerite,
Boehmite) and clay minerals containing aluminum hydrate (kaolinite, montmorillonite, halosite, pyrophyllite) and the like can be suitably used. From the viewpoint of gypsum, gypsite is most preferably used.

The powder obtained from aluminum hydrate, having a porous structure having a porosity of 0.01 to 1 CC / g, is heat-treated at a temperature equal to or higher than the dehydration temperature of the hydroxyl group contained in aluminum hydrate. Is obtained by For example, claim 2
Preferably, the aluminum hydrate is 20
It is obtained by performing a heat treatment in a temperature range of 0 to 600 ° C.

If the heat treatment temperature is lower than 200 ° C., the water of crystallization of aluminum hydrate does not dehydrate, so that when mechanical energy is applied thereafter, the amorphization reaction hardly proceeds and a large amount of mechanical energy is generated. Is needed.
In addition, mechanical treatment for a long time when applying a large amount of energy gives problems such as recrystallization. or,
If the temperature exceeds 600 ° C., the amount of dehydration of the water of crystallization of aluminum hydrate becomes too large, and the reactivity when mechanical energy is applied decreases.

By performing the heat treatment in the above-mentioned temperature range, the aluminum hydrate can be provided with the porous structure having the above-mentioned specific porosity, and the above-mentioned object of the present invention can be achieved even when the application of mechanical energy is reduced. It is possible to obtain a binder for an inorganic material to achieve. Activated alumina or activated clay which has been subjected to such a heat treatment in advance to have a porous structure may be used.

The amount of vacancy is 0.01 to 1 as described above.
Limited to CC / g. If the amount of vacancies is less than 0.01 CC / g, the amorphization reaction hardly proceeds when mechanical energy is applied, so that it takes a considerable amount of time to obtain excellent reactivity. This is because mechanical activation treatment for a long period of time causes a problem in that if mechanical activation is performed without sufficient cooling due to an increase in the temperature of the material, reactivity is lost due to recrystallization. Conversely, the vacancy amount is 1 CC / g
In this case, more hydroxyl groups need to be dehydrated. At this time, chemically stable alumina crystals are generated, and the amorphization reaction is difficult to proceed. A more preferable vacancy amount is 0.05 to 0.5 CC / g.

The calcium compound is not particularly limited, and may or may not be water of crystallization. Specifically, calcium hydroxide (Ca (OH) 2), calcium oxide (CaO), calcium silicate (C3S, C2S), calcium chloride and the like are suitably used, and also preferably used in the form of cement. Calcium hydroxide and calcium oxide which are inexpensive and excellent in solubility are most preferably used as industrial raw materials.

The particle size of the hydrate and calcium compound is not particularly limited, but from the viewpoint of dispersibility in cement,
The average particle size is preferably from 0.1 to 50 μm.

The mechanical energy applied individually to the porous powder obtained from the aluminum hydrate is not particularly limited, and may be, for example, energy due to compression force, shear force, impact force, friction force, or the like. Is mentioned.
The method for applying the mechanical energy is not particularly limited, and for example, the method can be performed using a pulverizer generally used for the purpose of pulverization. Examples of such a pulverizing device include a ball media mill in which impact, friction, compression, shearing, and the like are combined, such as a ball mill, a vibration mill, a planetary mill, and a media stirring mill; a roller mill; In addition, it is also possible to use a jet pulverizing apparatus mainly for impact and attrition. Among them, a ball-medium type mill is preferable because mechanical energy can be effectively applied to the mixture mechanically.

In applying the above-mentioned mechanical energy, it is preferable to use a grinding aid usually used when grinding cement clinker, quartz sand, limestone or the like. Such grinding aids are not particularly limited and include, for example, liquid ones such as alcohols such as methyl alcohol and ethanolamines such as triethanolamine; solid ones such as sodium stearate and calcium stearate; Examples include gaseous substances such as acetone vapor.

The mechanical energy is at least 0.1
kWh / kg or more. When it is less than 0.1 kWh / kg, the solubility of aluminum ions in the obtained active powder becomes low, and as a result, the curing rate of the cement when the active powder is added to the cement, which is the object of the present invention, is insufficient. Becomes The upper limit is not particularly limited, but if it exceeds 30 kWh / kg, excessive load on the crushing device, contamination of the treated powder due to severe wear of the ball or container as a medium, coarse particles due to aggregation of the treated powder, cost It is usually 30 kWh / kg or less, and preferably 0.1 kWh / kg
~ 0.5 kWh / kg.

The mechanical energy is calculated based on the total amount of electric power consumed by the pulverizer when the mixture is put into the pulverizer and actually operated. This is the amount of power obtained by subtracting the amount of power consumed (the amount of idling power).

The mixing ratio of the active powder obtained by applying mechanical energy to the calcium compound is not particularly limited. However, in order to obtain a good curing speed when added to cement, it is necessary to use Al / Ca. Is a molar ratio of 0.5 to
It is preferably in the range of 5.0. More preferably, 1.
The range is from 0 to 4.0. The mixing method is not particularly limited, and mixers such as an omni mixer and an Erich mixer can be suitably used.

The binder for inorganic material obtained as described above has an solubility of aluminum ions and calcium ions in water that is optimal for sufficiently promoting the setting and hardening of hydraulic materials such as cement. Is controlled. Therefore, a cement composition having a high curing speed can be obtained by adding to the cement, and a large amount of ettringite is not formed in the cured product, so that the cured product is excellent in dimensional stability and durability.

The above-mentioned cement is not particularly limited. For example, Portland cement such as ordinary Portland cement, early-strength Portland cement, ultra-high-strength Portland cement, moderate heat Portland cement, sulfate-resistant Portland cement, etc .; blast furnace cement, silica cement, Mixed cements such as fly ash cement; special cements such as white Portland cement, cement-based solidifying material, alumina cement and the like can be mentioned. Of these, ordinary Portland cement which is inexpensive and has stable quality can be suitably used.

In the cement composition according to the fifth aspect, the amount of the binder is not particularly limited, but is preferably 1 to 100 parts by weight based on 100 parts by weight of the cement. If the amount is less than 1 part by weight, it is difficult to exhibit the effect of the addition, and it is not possible to obtain sufficient setting speed and curing speed. On the other hand, when the amount exceeds 100 parts by weight, curing starts without obtaining sufficient workability, so that the pot life becomes a problem. More preferably, it is 3 to 50 parts by weight.

The method for adding the binder for inorganic material to the cement is not particularly limited as long as the binder for inorganic material can be uniformly dispersed in the cement. For example, a mixer such as an Erich mixer or an omni mixer may be used. Can be suitably used.

In the present invention, it has been described that the mechanical energy acts on the powder obtained from aluminum hydrate, but if necessary, mechanical energy acts on the calcium compound. You may let it.

[0026]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

(Examples 1 to 6 and Comparative Examples 1 to 3) Aluminum hydroxide (C-31, manufactured by Sumitomo Chemical Co., Gypsite) as an aluminum hydrate, and slaked lime (Kawai Lime Industry Co., Ltd.) as a calcium compound. Using. Aluminum hydroxide was previously heat-treated in an air atmosphere at a temperature and time shown in Table 1 by a degreasing furnace (manufactured by Peng Seisakusho) (Example 1).
To 5 and Comparative Example 3).

In Example 6, activated alumina (A
C-11, manufactured by Sumitomo Chemical Co., Ltd.) without heat treatment. With respect to the pore amount after the heat treatment, the total pore amount was obtained by the Kelvin equation from the adsorption amount at the saturated vapor pressure by the nitrogen adsorption method (ASAP200, Shimadzu Corporation), and shown in Table 1. After the heat treatment, activated powder was obtained by applying mechanical energy shown in Table 1 to the aluminum hydroxide by means of an ultra fine mill (AT-25, manufactured by Mitsubishi Heavy Industries, Ltd.).

When applying mechanical energy,
A zirconia ball of 10 mmφ was used as a ball medium. The input amount of the zirconia ball was 45 kg, the input amount of the compound was 2 kg, and 1 g of ethanol was added as a grinding aid.

When mechanical energy is applied to the heat-treated aluminum hydrate, the average energy density (the average energy per hour, which is obtained by the following formula,
The value obtained by dividing the mechanical energy applied to the heat-treated aluminum hydrate by the processing time) is about 0.5 kW / kg. Energy.

The applied mechanical energy (kWh / kg) =
電力 Amount of power consumed during operation when powder and medium are charged (kWh)-
Electric power consumed during idle operation (kWh) / Amount of processed powder (kg)

The obtained active powder and slaked lime are made of Al: Ca
Were weighed so that the mixing ratio was as shown in Table 1 in molar ratio, and mixed with an omni mixer to obtain a binder of the present invention. The above binder was added in an amount of 15 parts by weight (total amount of active powder and calcium compound) to 100 parts by weight of ordinary Portland cement (manufactured by Taiheiyo Cement Co.), and then mixed with an omni mixer to obtain a cement composition. Was prepared. The following methods were used to evaluate the quick-curing property of the obtained cement composition and the dimensional stability of the cured cement body.
The results are shown in Table 1.

[Evaluation Method] (1) Rapid curing property / setting speed 35 parts by weight of water was injected and kneaded with 100 parts by weight of the obtained cement composition to prepare a cement paste. Regarding the obtained cement paste, JIS R5201
A setting test was performed according to (Physical Testing Method for Cement 7. Setting Test) to determine the start and end of setting, and the difference was used as an index of setting speed. As a setting tester, an automatic setting tester (MIC-308-1, manufactured by Enai Seisakusho) was used. However, when the setting speed is extremely high and the measurement is impossible, after adding a setting retarder (Jet Setter, made by Chichibu Onoda Co.) to 100 parts by weight of the obtained cement composition, Was measured.

Curing speed The above-mentioned cement paste was cast into a cylindrical shape having a diameter of 5 cm and a height of 10 cm, and after 3 hours from the injection of water, the compressive strength of the cured product was measured. Index.

(2) Dimensional stability 100 parts by weight of the obtained cement composition, 50 parts by weight of 8-silica sand (manufactured by Rokuro Mining Co., Ltd.) and 40 parts by weight of water are kneaded. It was cast-molded into a dumbbell shape of × 150 mm × 10 mm. Thereafter, steam curing was performed in steam at 60 ° C. for 2 days to obtain a hardened cement. The obtained cured product is
A three-cycle test was carried out in a cycle of drying at a temperature of 1 day and immersion in water for one day. Dimensional change rate (%) = [(saturated size after test-initial size) /
(Initial size) x 100
Those exceeding 0.1 were rated as ×.

Example 7 A cement composition was prepared in the same manner as in Example 1 except that calcium oxide (manufactured by Kawai Lime Industry Co., Ltd.) was used as a calcium compound, and the obtained cement composition was evaluated. . The results are shown in Table 1.

(Comparative Example 4) As a cement, a cement composition to which no active powder was added using jet cement (manufactured by Chichibu Onoda Co.) was used. The rapid curing property of this cement composition and the dimensional stability of the cured cement body were evaluated in the same manner as in the examples. The results are shown in Table 1.

Comparative Example 5 Aluminum hydroxide (C-31, manufactured by Sumitomo Chemical Co., Ltd.) was used as aluminum hydrate, and slaked lime (manufactured by Kawai Lime Industry Co., Ltd.) was used as a calcium compound. These were weighed and mixed in advance so that the molar ratio of Al / Ca became 2/3, and 4 kWh / kg of this mixture was added to this mixture by an ultrafine mill (AT-20, manufactured by Mitsubishi Heavy Industries, Ltd.) without heat treatment. An active powder was obtained by applying mechanical energy.

When applying mechanical energy, zirconia balls having a diameter of 10 mm were used as a ball medium. The input amount of the zirconia ball was 45 kg, and the input amount of the compound was 2 kg. Further, 1 g of ethanol was added as a grinding aid. The active powder was added in an amount of 15 parts by weight with respect to 100 parts by weight of ordinary Portland cement (manufactured by Chichibu Onoda Co.), and then mixed by an omni mixer to prepare a cement composition.

The quick-curing property of the obtained cement composition and the dimensional stability of the cured cement were evaluated in the same manner as in Example 1. Table 1 shows the results.

[0041]

[Table 1]

The rapid setting of cement is mainly governed by the degree of amorphization of aluminum hydrate obtained by applying mechanical energy, that is, by mechanical activation. is there. Thus, FIG. 1 shows the relationship between the heat treatment time of aluminum hydrate and the increase in the amount of vacancies. From FIG. 1, it can be seen that the longer the heating time, the larger the total vacancy amount and the more porous the material.

[0043]

The binder for an inorganic material of the present invention is constituted as described above, and is obtained by using a powder obtained from aluminum hydrate and having a porous structure having a specified porosity. However, even if mechanical energy of lower energy is applied than before, amorphization will be sufficiently performed,
The dissolution properties of aluminum and calcium ions in water are well controlled. Therefore, it can be effectively used for a solid-liquid reaction utilizing aluminum or calcium in a liquid phase, and can sufficiently promote the setting and hardening of a hydraulic material such as cement. That is, the cement composition of the present invention comprising the above-mentioned binder for inorganic material and cement is a cement composition having a high setting speed and a high setting speed, and also forms a large amount of ettringite in a hardened body. Therefore, a cured product having excellent dimensional stability and durability can be obtained.

[0044]

[Brief description of the drawings]

FIG. 1 is a diagram showing the relationship between the heat treatment time of aluminum hydrate and the increase in the amount of vacancies.

Claims (5)

[Claims] 1. A method comprising applying a mechanical energy of at least 0.1 kWh / kg to a powder obtained from an aluminum hydrate having a porous structure having a porosity of 0.01 to 1 CC / g. A binder for an inorganic material, comprising a mixture of the obtained active powder and a calcium compound. 2. A powder obtained from an aluminum hydrate having the above-mentioned porous structure is made of aluminum hydrate by 20%.
The binder for an inorganic material according to claim 1, which is obtained by performing a heat treatment in a temperature range of 0 to 600 ° C. 3. The binder for an inorganic material according to claim 1, wherein the aluminum hydrate is gypsite. 4. The binder for an inorganic material according to claim 1, wherein the calcium compound is calcium hydroxide or calcium oxide. 5. A cement composition comprising a cement and the binder for an inorganic material according to any one of claims 1 to 4.