Production method of hydraulic powder

Abstract

To provide a method for producing a hydraulic powder in which atomization is suppressed.SOLUTION: A method for producing hydraulic powder includes mixing the following (B) component with the following (C) component, and mixing or stirring the mixture of the (B) and (C) components obtained by mixing with the following (A) component. Ingredients (A): cement clinker or cement powder; Ingredients (B): one or more of minerals, slag, and ash containing iron of less than 2.0 mass% in terms of iron oxide and having a Mohs hardness of 1 or more to 5 or less; Component (C): a compound represented by the following general formula (c1) or a salt thereof, which is as shown in the formula below (in the formula, R1c represents a hydrogen atom, a hydrocarbon group having 1 or more to 4 or less carbon atoms, a hydroxyalkyl group having 2 or more to 4 or less carbon atoms, or a polar functional group having 4 or more to 10 or less carbon atoms, and AO independently represents an alkylene oxide having 2 or more to 4 or less carbon atoms.).SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a method for producing hydraulic powder. [Background technology]

[0002] Cement concrete is produced by mixing Portland cement, water, fine aggregate, and coarse aggregate, shaping, and hardening it, and is an essential construction material for the development of mankind.

[0003] Portland cement is produced from the main ingredient cement clinker, which is obtained by drying, mixing, and firing limestone, clay, silica, and iron raw materials, but a large amount of CO2 is emitted during the firing process due to the decarbonation of limestone. In recent years, as part of efforts to reduce CO2 emissions in the cement industry, there have been considerations of promoting the use of blended cement, which mixes minerals, slag, or ash that exhibit (latent) hydraulic properties instead of cement clinker.

[0004] Admixtures to be mixed into blended cement; minerals, slag, ash, etc. exhibiting (latent) hydraulic properties include, for example, those with pozzolanic action (fly ash, silica fume, volcanic ash, silicic clay, calcined clay), those with latent hydraulic properties (blast furnace slag), and those that react with C3A (tricalcium aluminate) or C4AF (tetracalcium aluminate ferroferrate) (limestone).

[0005] Patent Document 1 discloses a cement composition having high strength and excellent fluidity, which contains a specified ordinary Portland cement clinker, gypsum, limestone, and an auxiliary agent containing an alkanolamine, in which the alkanolamine content in the total amount of the ordinary Portland cement clinker, gypsum, and auxiliary agent is 10 to 210 mg / kg, and the limestone content in the total amount of the ordinary Portland cement clinker, gypsum, auxiliary agent, and limestone is 3 to 10 mass %, and a method for producing the same. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2022-151074 A Summary of the Invention [Problem to be solved by the invention]

[0007] However, when manufacturing blended cement, if the raw materials such as cement clinker and admixtures are stirred and mixed together, the admixtures, which are softer than the cement clinker, can be excessively atomized, reducing the flowability of the powder and causing a deterioration in the working environment due to dust. In order to solve the above-mentioned problems, the cement clinker and the mixed materials are often crushed separately and then mixed in a later process. However, this requires new equipment for mixing the cement clinker and the mixed materials and equipment for storing the mixed materials, which results in problems such as increased investment. The present invention provides a method for producing hydraulic powder in which atomization is suppressed. [Means for solving the problem]

[0008] In one embodiment, the present invention provides a method for producing a hydraulic powder, which comprises mixing the following component (B) with the following component (C), and mixing or stirring the mixture of the components (B) and (C) obtained by mixing with the following component (A). (A) Component: Cement clinker or cement powder (B) Component: One or more selected from minerals, slag, and ash, each of which contains less than 2.0% by mass of iron in terms of iron oxide and has a Mohs hardness of 1 or more and 5 or less. Component (C): a compound represented by the following general formula (c1) or a salt thereof

[0009] [ka]

[0010] [In the formula, R 1crepresents a hydrogen atom, a hydrocarbon group having from 1 to 4 carbon atoms, a hydroxyalkyl group having from 2 to 4 carbon atoms, or a polar functional group having from 4 to 10 carbon atoms, and each AO independently represents an alkylene oxide having from 2 to 4 carbon atoms.

[0011] In another embodiment, the present invention provides a method for producing a hydraulic powder, which comprises mixing the component (A) with the component (C), and mixing or stirring the mixture of the components (A) and (C) obtained by mixing with the component (B). Effect of the Invention

[0012] According to the present invention, there is provided a method for producing hydraulic powder in which atomization is suppressed. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] In recent years, the SDGs have been proposed to realize a sustainable society. This invention contributes to improving the productivity of blended cement and is considered to be a technology that can contribute to SDGs No. 9, 11, 12, and 13, for example.

[0014] The inventors have found that when mixing or stirring the clinker or Portland cement (A) and the admixture (B), the presence of a specific compound (C) in advance suppresses the atomization of the mixed cement. The reason why such an effect is exhibited is not entirely clear, but is presumed to be as follows. It is believed that the atomization of admixtures progresses as a result of the relatively soft admixture repeatedly coming into contact with the relatively hard cement clinker during the stirring and mixing process. Component (C) has functional groups that can act electrostatically on the catiosite on the admixture surface, and thus covers and protects the admixture surface, thereby suppressing the atomization of the admixture. It is presumed that by mixing and stirring components (A) and (B) and then adding component (C) before mechanical force is applied, component (C) has the function of suppressing the atomization of the soft mixture by the mechanical force while achieving uniform mixing of the two. On the other hand, when an admixture containing a large amount of iron is used, component (C), which adsorbs to iron in no small amount, is adsorbed to sites on the surface of the admixture that contain a large amount of iron, resulting in poor coverage of the entire admixture and a decrease in the ability to suppress atomization. However, the method for producing hydraulic powder of the present invention is not limited to this mechanism at all.

[0015] <Manufacturing method of hydraulic powder> In an exemplary embodiment, the method for producing a hydraulic powder of the present invention involves mixing or stirring a mixture containing the following component (A) and the following component (B) in the presence of the following component (C). (A) Component: Cement clinker or cement powder (B) Component: One or more selected from minerals, slag, and ash, each of which contains less than 2.0% by mass of iron in terms of iron oxide and has a Mohs hardness of 1 or more and 5 or less. Component (C): a compound represented by the following general formula (c1) or a salt thereof

[0016] [ka]

[0017] [In the formula, R 1c represents a hydrogen atom, a hydrocarbon group having from 1 to 4 carbon atoms, a hydroxyalkyl group having from 2 to 4 carbon atoms, or a polar functional group having from 4 to 10 carbon atoms, and each AO independently represents an alkylene oxide having from 2 to 4 carbon atoms.

[0018] In addition, in an exemplary embodiment, the present invention provides a method for producing a hydraulic powder, which includes mixing the component (B) with the component (C), and mixing or stirring the mixture of the components (B) and (C) obtained by mixing with the component (A). In this method for producing hydraulic powder, the component (A) to be mixed or stirred with the mixture of the components (B) and (C) obtained by mixing may be one that has been previously mixed with the component (C).

[0019] In an exemplary embodiment, the present invention provides a method for producing a hydraulic powder, which comprises mixing the component (A) with the component (C), and mixing or stirring the mixture of the components (A) and (C) obtained by mixing with the component (B). In this method for producing hydraulic powder, the component (B) to be mixed or stirred with the mixture of the components (A) and (C) obtained by mixing may be a component that has been previously mixed with the component (C).

[0020] In order to further suppress the atomization of the hydraulic powder, the method for producing the hydraulic powder of the present invention is preferably a method for producing the hydraulic powder in which the component (B) and the component (C) are mixed, and the obtained mixture is mixed or stirred with the component (A).

[0021] The method for producing a hydraulic powder of the present invention may be a method for producing a hydraulic powder in which either one of the components (A) and (B) is mixed or stirred with the other component (C). In addition, the method for producing a hydraulic powder of the present invention may be a method for producing a hydraulic powder in which either one of the components (A) and (B) is mixed with the component (C), and then the other is added and mixed or stirred.

[0022] In the method for producing hydraulic powder of the present invention, stirring a mixture containing components (A) and (B) in the presence of component (C) means stirring the mixture in a state in which component (C) is contained in the mixture. In addition, the method for producing a hydraulic powder of the present invention may be a method for producing a hydraulic powder, which comprises adding component (C) to a mixture of components (A) and (B) and stirring the mixture to which component (C) has been added. Specifically, from the viewpoint of suppressing a decrease in particle size of component (B) due to direct contact between component (A) and component (B), preferred methods include a method in which component (B) is added to a mixture of components (A) and (C) and stirred, a method in which component (A) is added to a mixture of components (B) and (C) and stirred, and a method in which components (A) and (B) are added to component (C) and stirred.

[0023] The method of adding component (C) includes a method of supplying a liquid mixture containing component (C), preferably in the form of a solution, by dropping, spraying, or the like. In addition to component (C), other components, such as antifoaming agents, water, known grinding aids, and the like, can be mixed into the mixture of components (A) and (B) as necessary. When adding component (C) to a mixture of components (A) and (B), or adding component (C) and the other components, the total amount to be used may be added all at once, or may be added in portions. In addition, component (C) may be added by supplying it continuously or intermittently. Specifically, component (C) may be added by spraying or supporting it on component (A) or component (B), and mixing or stirring may be started after components (A), (B), and (C) have all been added; alternatively, component (A) or component (B) and component (C) may be mixed or stirred for a certain period of time, and then the remaining component (B) or component (A) may be added and mixed or stirred again.

[0024] <Component (A)> Component (A) is cement clinker or cement powder. Cement clinker is obtained by burning raw materials such as limestone, clay, and iron slag (it may also contain gypsum), and has the property of hardening when it reacts with water. In the present invention, the hydraulic powder is a hydraulic material. Examples of materials that react with water to harden include oxides of alkaline earth metals, SiO2, Al2O3, Fe2O3, TiO2, P2O5, ZnO, and other oxides. These generally form hydrates at room temperature or under hydrothermal conditions. For example, cement clinker contains 3CaO·SiO2 (C3S: alite), 2CaO·SiO2 (C2S: belite), 3CaO·Al2O3 (C3A: calcium aluminate), and 4CaO·Al2O3·Fe2O3 (C4AF: calcium aluminoferrite) as components. The cement clinker may be, for example, a clinker obtained by firing a mixture containing one or more selected from limestone (CaCO3), clay (Al2O3, SiO2), silica (SiO2), iron slag (Fe2O3), various incineration ashes containing mineral components, dried powder of lime-treated sewage sludge, and other raw materials generally used for cement production. The cement powder may be cement, or even Portland cement. Portland cement is prepared by pre-pulverizing cement clinker, adding an appropriate amount of gypsum, and finish-pulverizing the mixture to obtain a powder with a specific surface area of, for example, 2,500 cm2 (Blaine value). 2 / g or more, or BET specific surface area of ​​0.8 m 2 Examples of such cement include ordinary Portland cement, early strength Portland cement, ultra early strength Portland cement, sulfate resistant Portland cement, low heat Portland cement, white Portland cement, and ecocement (e.g., JIS R 5214, etc.). Among these, from the viewpoint of shortening the time required for the hydraulic composition to reach a required strength, a cement selected from early strength Portland cement, ordinary Portland cement, sulfate resistant Portland cement, and white Portland cement is preferred, and a cement selected from early strength Portland cement and ordinary Portland cement is more preferred. From the viewpoint of achieving the effects of the present invention more effectively, the component (A) is preferably cement clinker or Portland cement, and more preferably cement clinker.

[0025] The average particle size of the component (A) to be mixed with the component (B) is not particularly limited, but from the viewpoints of powder fluidity and dust suppression, it is preferably 1 μm or more, more preferably 5 μm or more, and even more preferably 10 μm or more, and from the viewpoint of the strength of the hardened body of the hydraulic composition, it is preferably 100 μm or less, more preferably 50 μm or less, and even more preferably 25 μm or less. The average particle size of component (A) is determined by measuring the particle size distribution using a laser diffraction / scattering particle size distribution analyzer (LA-920, manufactured by Horiba, Ltd.) and ethanol (95) (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) as a dispersion medium, and the arithmetic mean diameter is defined as the average particle size (μm). When the components (A), (B), and (C) are mixed and the mixture is stirred to pulverize the component (A), the component (A) can be, for example, in the form of a block, regardless of the average particle size described above.

[0026] <(B) component> Component (B) is one or more selected from minerals, slag, and ash, which contain less than 2.0% by mass of iron, calculated as iron oxide, and have a Mohs hardness of from 1 to 5. Component (B) may optionally contain iron, and may contain less than 2.0% by mass of iron, calculated as iron oxide. Examples of component (B) include carbonate minerals such as calcium carbonate, magnesite, and dolomite; powders having pozzolanic action such as fly ash, silica fume, volcanic ash, woody biomass combustion ash, and silicate clay; latent hydraulic powders such as coal ash, blast furnace slag, and diatomaceous earth; and silicate minerals such as kaolin, aluminum silicate, clay, talc, mica, calcium silicate, sericite, and bentonite. From the viewpoint of the micronization suppression effect, one or more types selected from carbonate minerals, latent hydraulic powders, and silicate minerals are preferred. Component (B) is preferably one of the above components that contains less than 2.0% by mass of iron in terms of iron oxide and has a Mohs hardness of 1 or more and 5 or less. From the viewpoint of the effect of suppressing atomization, the component (B) more preferably contains one or more selected from calcium carbonate, kaolin, and dolomite.

[0027] From the viewpoint of strength development of the hydraulic composition, the component (B) contains iron in an amount of preferably 0 mass % or more, more preferably 0.01 mass % or more, calculated as iron oxide, and from the viewpoint of the effect of suppressing microparticulation, the amount is less than 2.0 mass %, preferably 1.5 mass % or less, more preferably 1.0 mass % or less. The iron content of the component (B) is measured by the following method.

[0028] <Method for measuring the iron content of component (B)> The iron content of component (B) is measured using a powder X-ray device (RINT-2500, manufactured by Rigaku Corporation). The measurement conditions are CuKα target, 40mA tube current, 200kV tube voltage, 5-70deg, 2θ scanning range, step scanning, 0.02° step width, 2 seconds counting time. Then, 10 parts by mass of α-corundum (Al2O3) is added to component (B) as a standard substance, and the iron content is calculated in terms of iron oxide (Fe2O3) using Rietveld analysis software based on the peak area of ​​the standard substance. The Rietveld analysis software used is PDXL Ver.1.8 manufactured by Rigaku Corporation.

[0029] From the viewpoint of the strength of the hydraulic composition hardened body, the Mohs hardness of the (B) component is 1 or more, preferably 1.5 or more, more preferably 2 or more, and from the viewpoint of the effect of suppressing atomization, it is 5 or less, preferably 4.5 or less, more preferably 4 or less. The Mohs hardness of the (B) component is measured by the following method.

[0030] <Method for measuring Mohs hardness of component (B)> The Mohs hardness of component (B) is a hardness obtained by using the hardness of 10 kinds of standard minerals as a scale, and is measured using a Mohs hardness tester (manufactured by Tokyo Science Co., Ltd.). The standard minerals are, in order from soft minerals (Mohs hardness 1) to hard minerals (Mohs hardness 10), talc, gypsum, calcite, fluorite, apatite, orthoclase, quartz, topaz, corundum, and diamond. In this specification, the hardness is determined by the presence or absence of scratches when the target sample is rubbed with these standard minerals. For example, the Mohs hardness of a target sample that is not scratched by calcite but is scratched by fluorite is 3.5.

[0031] The average particle size of the component (B) mixed with the component (A) is not particularly limited, but from the viewpoints of powder fluidity and dust suppression, it is preferably 1 μm or more, more preferably 5 μm or more, and even more preferably 25 μm or more, and from the viewpoint of the strength of the hardened body of the hydraulic composition, it is preferably 100 μm or less, more preferably 70 μm or less, and even more preferably 35 μm or less. The average particle size of component (B) is measured by measuring the particle size distribution using a laser diffraction / scattering particle size distribution analyzer (LA-920, manufactured by Horiba, Ltd.) and ethanol (95) (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) as a dispersion medium, and the arithmetic mean diameter is taken as the average particle size (μm). In addition, when the components (A), (B), and (C) are mixed and the mixture is stirred to pulverize the component (B), the component (B) can be, for example, in the form of a lump, regardless of the average particle size described above.

[0032] <(C) component> The component (C) is a compound represented by the above general formula (c1) or a salt thereof. The component (C) can be used alone or in combination of two or more. The salt of the compound represented by the above general formula (c1) is not particularly limited, but is preferably a halide or a carboxylate, more preferably a chloride, an acetate, a lactate, or a salt with a polycarboxylic acid dispersant.

[0033] In general formula (c1), R 1c is a hydrogen atom, a hydrocarbon group having from 1 to 4 carbon atoms, a hydroxyalkyl group having from 2 to 4 carbon atoms, or a polar functional group having from 4 to 10 carbon atoms.

[0034] In general formula (c1), R 1c From the viewpoint of the effect of suppressing atomization, the hydrocarbon group having 1 to 4 carbon atoms is preferably a methyl group, an ethyl group, or a propyl group. In addition, in the general formula (c1), R 1c From the viewpoint of the effect of suppressing atomization, the hydroxyalkyl group having 2 to 4 carbon atoms is preferably a hydroxyethyl group or a hydroxypropyl group. In addition, in the general formula (c1), R 1cExamples of the polar functional group having 4 to 10 carbon atoms include a functional group having a structure represented by the following general formula (c2), a tris(hydroxymethyl)methyl group, or a 6-(bis(hydroxyethyl)amino)-6-oxohexanoyl group, with a 2,2'-((2-ethyl)azanediyl)bis(ethan-1-ol) group, a tris(hydroxymethyl)methyl group, or a 6-(bis(hydroxyethyl)amino)-6-oxohexanoyl group being preferred, and a 2,2'-((2-ethyl)azanediyl)bis(ethan-1-ol) group being more preferred.

[0035] [ka]

[0036] [In the formula, R 2c and R 3c are each independently a hydroxyalkyl group having 1 to 4 carbon atoms; R 4c is an alkylene group having 1 to 4 carbon atoms.

[0037] In general formula (c2), R 2c and R 3c From the viewpoint of the effect of suppressing atomization, each of the hydroxyalkyl groups having 1 to 4 carbon atoms is preferably a hydroxyethyl group or a hydroxypropyl group. In general formula (c2), R 4c The alkylene group having 1 to 4 carbon atoms may be an ethylene group, a propylene group, or a butene group. From the viewpoint of the effect of suppressing atomization, an ethylene group is preferable.

[0038] In general formula (c1), R 1c From the viewpoint of the effect of suppressing atomization, is preferably a hydrogen atom or a polar functional group having 4 to 10 carbon atoms, more preferably a hydrogen atom or 2,2'-((2-ethyl)azanediyl)bis(ethan-1-ol), and even more preferably a hydrogen atom. In the general formula (c1), from the viewpoint of the effect of suppressing atomization, it is preferable that AO is each independently EO (ethylene oxide) or PO (propylene oxide).

[0039] In the method for producing hydraulic powder of the present invention, the component (C) is preferably such that the mass ratio (aB) / (aA) of the amount (aA) of the component (C) adsorbed to the component (A) and the amount (aB) of the component (C) adsorbed to the component (B) is 1.0 or more. In the method for producing hydraulic powder of the present invention, from the viewpoint of the effect of suppressing atomization, the mass ratio (aB) / (aA) of the (C) component is preferably 1.0 or more, more preferably 1.3 or more, even more preferably 1.5 or more, and is preferably 10.0 or less, more preferably 8.0 or less, even more preferably 6.0 or less. The amount (aA) of component (C) adsorbed to component (A) was measured by the following method. The amount (aB) of component (C) adsorbed to component (B) was measured by the same method as below, except that component (A) was replaced with component (B). The mass ratio (aB) / (aA) may be the mass ratio (aB) / (aA) of the amount (aA) of the component (C) adsorbed to the component (A) in the component (A) per unit mass to the amount (aB) of the component (C) adsorbed to the component (B) in the component (B) per unit mass. The adsorption amount (aA) of the component (C) to the component (A) or the adsorption amount (aB) of the component (C) to the component (B) is the adsorption amount of the component (C) in the component (A) or the component (B) before the components (A) and (B) are mixed.

[0040] <Method for measuring the amount (aA) of component (C) adsorbed to component (A)> All test materials are adjusted to 20°C in advance. 0.01 g of component (C) is added to a 50 mL centrifuge tube and diluted with tap water to prepare an aqueous solution of component (C) with a concentration of 400 ppm. Next, 25 g of component (A) is placed in this centrifuge tube and mixed by inversion for 1 minute to prepare a cement paste. The cement paste immediately after preparation is centrifuged at 3,000 rpm for 1 minute, and then the supernatant is filtered using a membrane filter (DISMIC 25HP045AN, manufactured by Advantec Co., Ltd.). The resulting filtrate is diluted 20 times with 0.02 mol / L HClaq. The TOC (mg / L) detected in the diluted filtrate by a combustion catalytic oxidation method using an online total organic carbon meter (TOC-V, manufactured by Shimadzu Corporation) is converted to the concentration of component (C) from a calibration curve created by diluting component (C) in advance, and the amount of adsorption (aA) of component (C) relative to component (A) is calculated from the concentration of the non-adsorbed portion of component (C) relative to component (A).

[0041] Examples of the component (C) include one or more selected from diethanolamine and its derivatives, diisopropanolamine and its derivatives, and N,N,N',N'-tetrakis(2-hydroxyethyl)ethylenediamine and its derivatives. Among these, from the viewpoint of the atomization suppression effect, one or more selected from diethanolamine and its derivatives are preferred, and one or more selected from diethanolamine and its derivatives in which the mass ratio (aB) / (aA) satisfies the above range are more preferred.

[0042] Specifically, from the viewpoint of the atomization suppression effect, the (C) component is preferably one or more selected from diethanolamine, diisopropanolamine, and N,N,N',N'-tetrakis(2-hydroxyethyl)ethylenediamine, and more preferably one or more selected from diethanolamine and diisopropanolamine.

[0043] <Mixing amount of each ingredient, etc.> In the method for producing hydraulic powder of the present invention, the (A) component is mixed in an amount of preferably 50 parts by mass or more, more preferably 60 parts by mass or more, and even more preferably 70 parts by mass or more, relative to 100 parts by mass of the total amount of the mixed amounts of the (A) component and the (B) component, from the viewpoint of strength expression, and preferably 99 parts by mass or less, more preferably 95 parts by mass or less, and even more preferably 90 parts by mass or less, from the viewpoint of the effect of suppressing micronization.

[0044] In the method for producing the hydraulic powder of the present invention, the (B) component is mixed in an amount of preferably 1 part by mass or more, more preferably 5 parts by mass or more, and even more preferably 10 parts by mass or more, relative to 100 parts by mass of the total amount of the mixed amounts of the (A) component and the (B) component, from the viewpoint of the effect of inhibiting micronization, and preferably 50 parts by mass or less, more preferably 40 parts by mass or less, and even more preferably 30 parts by mass or less, from the viewpoint of the strength expression of the hydraulic composition.

[0045] In the method for producing the hydraulic powder of the present invention, the (A) and (B) components are mixed so that the mass ratio ((A) / (B)) of the mixed amount of the (A) component to the mixed amount of the (B) component is preferably 1 or more, more preferably 1.5 or more, and even more preferably 2.0 or more from the viewpoint of the strength expression of the hydraulic composition, and is preferably 99 or less, more preferably 19 or less, and even more preferably 9 or less from the viewpoint of the microparticulation suppression effect.

[0046] In the method for producing hydraulic powder of the present invention, the (C) component is mixed in an amount of preferably 0.005 parts by mass or more, more preferably 0.0075 parts by mass or more, and even more preferably 0.01 parts by mass or more, relative to 100 parts by mass of the total of the mixed amounts of the (A) component and the (B) component, from the viewpoint of the effect of inhibiting atomization, and preferably 0.5 parts by mass or less, more preferably 0.3 parts by mass or less, and even more preferably 0.1 parts by mass or less.

[0047] In the method for producing the hydraulic powder of the present invention, any of the optional components listed for the hydraulic powder of the present invention, which will be described in detail later, can be mixed in any desired manner.

[0048] The hydraulic powder produced by the method for producing hydraulic powder of the present invention preferably contains a substance that reacts with water or an alkaline substance to harden, and more preferably contains a substance that reacts with water to harden, particularly clinker, and one or more admixtures selected from the group consisting of blast furnace slag, fly ash, and silica fume [hereinafter referred to as admixture (a)]. Admixture (a) contains component (B) and may contain minerals, slag, and ash that do not fall under component (B). The content of admixture (a) in the hydraulic powder is preferably 8% by mass or more, more preferably 25% by mass or more, even more preferably 40% by mass or more, and preferably 80% by mass or less, more preferably 70% by mass or less, and even more preferably 60% by mass or less, from the viewpoint of the strength improvement rate from the non-additive in the 3-day strength. The remainder of this content is preferably a substance that reacts with water to harden. Therefore, the hydraulic powder containing the admixture (a) has a content of a substance having a property of reacting with water and hardening such as clinker in the hydraulic powder of preferably 20% by mass or more, more preferably 30% by mass or more, even more preferably 40% by mass or more, and preferably 92% by mass or less, more preferably 75% by mass or less, and even more preferably 60% by mass or less. The total content of a substance having a property of reacting with water or an alkaline substance such as clinker and hardening such as clinker and the admixture (a) in the hydraulic compound is preferably 70% by mass or more, more preferably 90% by mass or more, and preferably 100% by mass or less, and may be 100% by mass. The manufacturing method of the hydraulic powder of the present invention is suitable as a manufacturing method of a mixed cement (for example, JISR 5211-5213).

[0049] When obtaining Portland cement as a hydraulic powder, for example, Portland cement is prepared by pre-crushing clinker (also called cement clinker, which may contain gypsum), a hydraulic compound obtained by burning raw materials such as limestone, clay, and iron slag, and limestone, which is component (B), adding an appropriate amount of gypsum, and finish-crushing the mixture to a powder with a predetermined specific surface area, for example, a Blaine value of 2,500 cm. 2 / g or more, or BET specific surface area of ​​0.8 m 2 / g or more. Similarly, hydraulic powder containing the admixture can be produced by using clinker together with the admixture (for example, the admixture containing limestone, which is component (B)).

[0050] In the method for producing hydraulic powder of the present invention, the stirring conditions may be adjusted to obtain powder of an appropriate particle size depending on the raw material, application (cement strength class), etc. Generally, the Blaine value is preferably 2,500 cm 2 / g or more, more preferably 3,000 cm 2 / g or more, and preferably 5,000 cm 2 / g or less, more preferably 4,000 cm 2 It is preferable to stir the mixture of components (A) and (B) until the mixture becomes a powder with a density of 0.1 m / g or less. In addition, the density (specific gravity) of the mixture of components (A) and (B) is unknown, making it difficult to measure the Blaine value. In this case, the BET specific surface area can be used instead. The BET specific surface area is a gas adsorption method in which gas particles such as nitrogen (N2) are adsorbed onto solid particles and the surface area is measured from the amount of adsorption. Specifically, the specific surface area is determined by measuring the monomolecular adsorption amount VM according to the BET equation (Brunauer, Emmet and Teller's equation) based on the relationship between the pressure P and the amount of adsorption V. When stirring the mixture of components (A) and (B), the BET specific surface area is preferably 0.8 m 2 / g or more, more preferably 1.2m 2 / g or more, and preferably 3.0m 2 / g or less, more preferably 2.5m 2 It is preferable to stir the mixture until the mixture becomes a powder with a specific surface area of ​​0.1 to 1.0 μm / g or less. The target specific surface area, whether it is the Blaine value or the BET specific surface area, can be obtained, for example, by adjusting the stirring time. The specific surface area tends to increase when the stirring time is increased, and decrease when the stirring time is decreased. With regard to the specific surface area, for example, by increasing the stirring time in the production method of the present invention to increase the BET specific surface area of ​​the hydraulic powder, the time until the hydraulic composition reaches the required strength can be further shortened.

[0051] In addition, in the method for producing hydraulic powder of the present invention, it is preferable to stir the mixture of components (A) and (B) so that the average particle size of the hydraulic powder is preferably 10 μm or more, more preferably 15 μm or more, and even more preferably 20 μm or more from the viewpoint of the handleability of the hydraulic powder, and is preferably 50 μm or less, more preferably 40 μm or less, and even more preferably 30 μm or less from the viewpoint of the strength expression of the hydraulic composition. The average particle size of the hydraulic powder is a value measured by the method described in the Examples below.

[0052] In the method for producing hydraulic powder of the present invention, the stirring device used for stirring hydraulic compounds such as a mixture containing components (A) and (B) is not particularly limited, but examples thereof include ball mills and Roche mills that are commonly used for grinding cement, etc. The material of the stirring medium of the device is preferably one having a hardness equal to or greater than that of the material to be stirred (e.g., calcium aluminate in the case of cement clinker), and examples of commercially available products that can be generally obtained include steel, stainless steel, alumina, zirconia, titania, and tungsten carbide. The material to be stirred may be a material to be ground. The stirring medium may be a grinding medium.

[0053] In the method for producing hydraulic powder of the present invention, the mixture of components (A), (B) and (C) can be mixed or stirred in a grinding machine having a rotatable body of a horizontally long cylinder, for example, though there is no particular limitation. By placing the material to be stirred and a stirring medium in the body and rotating the body in the circumferential direction around the axis of the cylinder, the material to be stirred can be crushed by the impact caused by contact between the material to be stirred and the stirring medium inside the body.

[0054] From the viewpoint of productivity, the speed of the body is preferably 1 rpm or more, more preferably 5 rpm or more, even more preferably 10 rpm or more, and preferably 50 rpm or less, more preferably 35 rpm or less, even more preferably 20 rpm or less.

[0055] <Hydraulic powder> According to the method for producing hydraulic powder of the present invention, it is possible to produce hydraulic powder in which atomization is suppressed (hereinafter, also referred to as hydraulic powder of the present invention). In an exemplary embodiment, the hydraulic powder of the present invention is a hydraulic powder containing components (A), (B) and (C). The preferred embodiments of the components (A), (B) and (C) in the hydraulic powder of the present invention are the same as the preferred embodiments of the components (A), (B) and (C) described in the method for producing the hydraulic powder of the present invention.

[0056] <Composition of hydraulic powder> The hydraulic powder of the present invention contains the (A) component in an amount of preferably 50 parts by mass or more, more preferably 60 parts by mass or more, and even more preferably 70 parts by mass or more, based on 100 parts by mass of the total of the (A) component and the (B) component in the hydraulic powder, from the viewpoint of strength expression, and preferably 99 parts by mass or less, more preferably 95 parts by mass or less, and even more preferably 90 parts by mass or less, from the viewpoint of the micronization suppression effect.

[0057] In the hydraulic powder of the present invention, the content of component (A) is preferably 50% by mass or more, more preferably 60% by mass or more, and even more preferably 70% by mass or more, from the viewpoint of strength expression, and is preferably 99% by mass or less, more preferably 95% by mass or less, and even more preferably 90% by mass or less, from the viewpoint of the effect of suppressing microparticulation.

[0058] The hydraulic powder of the present invention contains the (B) component in an amount of preferably 1 part by mass or more, more preferably 5 parts by mass or more, and even more preferably 10 parts by mass or more, based on 100 parts by mass of the total of the (A) component and the (B) component in the hydraulic powder, from the viewpoint of the effect of inhibiting micronization, and preferably 50 parts by mass or less, more preferably 40 parts by mass or less, and even more preferably 30 parts by mass or less, from the viewpoint of the strength expression of the hydraulic composition.

[0059] In the hydraulic powder of the present invention, the content of component (B) is preferably 1 mass% or more, more preferably 5 mass% or more, and even more preferably 10 mass% or more from the viewpoint of the micronization suppression effect, and is preferably 50 mass% or less, more preferably 40 mass% or less, and even more preferably 30 mass% or less from the viewpoint of the strength expression of the hydraulic composition.

[0060] In the hydraulic powder of the present invention, the mass ratio ((A) / (B)) of the content of the (A) component to the content of the (B) component is preferably 1 or more, more preferably 1.5 or more, and even more preferably 2.0 or more, from the viewpoint of the strength expression of the hydraulic composition, and is preferably 99 or less, more preferably 19 or less, and even more preferably 9 or less, from the viewpoint of the microparticulation suppression effect.

[0061] The hydraulic powder of the present invention contains the (C) component in an amount of preferably 0.005 parts by mass or more, more preferably 0.0075 parts by mass or more, and even more preferably 0.01 parts by mass or more, based on 100 parts by mass of the total of the (A) and (B) components in the hydraulic powder, from the viewpoint of the micronization suppression effect, and preferably 0.5 parts by mass or less, more preferably 0.3 parts by mass or less, and even more preferably 0.1 parts by mass or less, based on the viewpoint of the micronization suppression effect.

[0062] In the hydraulic powder of the present invention, the content of component (C) is preferably 0.005% by mass or more, more preferably 0.0075% by mass or more, even more preferably 0.01% by mass or more, from the viewpoint of the micronization suppression effect, and is preferably 0.5% by mass or less, more preferably 0.3% by mass or less, even more preferably 0.1% by mass or less, from the viewpoint of the micronization suppression effect.

[0063] The hydraulic powder of the present invention may optionally contain an antifoaming agent, water, a known grinding aid, and the like.

[0064] In an exemplary embodiment, the hydraulic powder of the present invention may be a hydraulic powder comprising a blend of components (A), (B), and (C). The hydraulic powder of the present invention may further comprise the above-mentioned optional components.

[0065] The blending amounts of the (A) component, the (B) component, the (C) component and the optional components in the hydraulic powder of the present invention can be applied by replacing the preferred blending amounts of each component in the manufacturing method of the hydraulic powder of the present invention with the blending amounts. Also, the mass ratio of the blending amounts of each component in the hydraulic powder of the present invention can be applied by replacing the mass ratio of the blending amounts of each component in the manufacturing method of the hydraulic powder of the present invention with the mass ratio of the blending amounts.

[0066] The hydraulic powder obtained by the production method of the present invention can be used as a material for concrete structures and concrete products. The hydraulic composition using the hydraulic powder obtained by the manufacturing method of the present invention has improved compressive strength, especially early strength, when hardened. This hydraulic composition can be manufactured by mixing the hydraulic powder obtained by the manufacturing method of the present invention with water. EXAMPLES

[0067] <Materials used> <Component (A)> (A) Ingredient: Ordinary Portland cement (average particle size 21.8 μm, manufactured by Taiheiyo Cement Corporation)

[0068] <(B) component> B-1: Calcium carbonate fine powder (average particle size 31.3 μm, manufactured by Shimizu Kogyo Co., Ltd.) B-2: Dolomite (average particle size 29.1 μm, manufactured by Shimizu Kogyo Co., Ltd.)

[0069] <(C) component> C-1: Diethanolamine (Tokyo Chemical Industry Co., Ltd.) C-2: N,N,N',N'-tetrakis(2-hydroxyethyl)ethylenediamine (Tokyo Chemical Industry Co., Ltd.) C-3: Diisopropanolamine (DL-, meso-mixture) (Tokyo Chemical Industry Co., Ltd.) C-4: N-methyldiethanolamine (Tokyo Chemical Industry Co., Ltd.) C-5: Triisopropanolamine (mixture of isomers) (Tokyo Chemical Industry Co., Ltd.)

[0070] The iron content and Mohs hardness of component (B) shown in Table 1 were measured by the following method.

[0071] <Method for measuring the iron content of component (B)> The iron content of component (B) was measured using a powder X-ray analyzer (RINT-2500, manufactured by Rigaku Corporation). The measurement conditions were CuKα target, 40mA tube current, 200kV tube voltage, 5-70deg, 2θ scanning range, step scanning, 0.02° step width, and 2 seconds counting time. 10 parts by mass of α-corundum (Al2O3) was added to component (B) as a standard substance, and the iron content was calculated in terms of iron oxide (Fe2O3) using Rietveld analysis software based on the peak area of ​​the standard substance. PDXL Ver.1.8 manufactured by Rigaku Corporation was used as the Rietveld analysis software.

[0072] <Method for measuring Mohs hardness of component (B)> The Mohs hardness of the (B) component was measured using a Mohs hardness tester (manufactured by Tokyo Science Co., Ltd.) The reference minerals, in order from soft (Mohs hardness 1) to hard (Mohs hardness 10), were talc, gypsum, calcite, fluorite, apatite, orthoclase, quartz, topaz, corundum, and diamond. The hardness was determined by the presence or absence of scratches when the target sample was rubbed with these reference minerals.

[0073] <Calculation method of (aB) / (aA) for component (C)> First, components (A) and (B) were adjusted to 20° C. 0.01 g of component (C) was added to a 50 mL centrifuge tube and diluted with tap water to prepare an aqueous solution with a component (C) concentration of 400 ppm. 25 g of component (A) or component (B) was added to this aqueous solution and mixed by inversion for 1 minute to prepare a cement paste. The cement paste immediately after preparation was centrifuged at 3,000 rpm for 1 minute, and the supernatant was filtered using a membrane filter (DISMIC 25HP045AN, manufactured by Advantec Co., Ltd.). The resulting filtrate was diluted 20 times with 0.02 mol / L HClaq. The amount of adsorption (aA) or amount of adsorption (aB) of component (C) relative to component (A) or component (B) was calculated from the concentration of the non-adsorbed portion of component (C) relative to component (A) or component (B) detected in the diluted filtrate using an online total organic carbon meter (TOC-V, manufactured by Shimadzu Corporation). The mass ratio (aB) / (aA) of the amount of adsorption of the component (C) in component (B) to the amount of adsorption of the component (C) in component (A) was calculated based on the amount of adsorption of the component (C) in component (A) (aA) and the amount of adsorption of the component (C) in component (B) (aB).

[0074] <Example 1 and Comparative Example 1> (1) Stirring and mixing of hydraulic powder The above components (A), (B), and (C) were placed in a mixer (MX-X301, manufactured by Panasonic Corporation) in the amounts shown in Table 1, and after stirring for 2 minutes, the mixture was cooled to 20°C to obtain a hydraulic powder. In Examples 1-1 to 1-10, the component (C) was sprayed onto the component (B), and then the component (A) was added and mixing or stirring was started. In addition, in Example 1-11, the component (C) was sprayed onto the component (A), and then the component (B) was added and mixing or stirring was started. In Comparative Example 1-1, the components (A) and (B) were placed in the mixer in the amounts shown in Table 1, and after stirring for 1 minute, the component (C) was added. After stirring for another minute, the mixture was cooled to 20°C to obtain a hydraulic powder.

[0075] (2) Average particle size analysis method for hydraulic powder The hydraulic powders of the Examples and Comparative Examples prepared by the method (1) above were subjected to particle size distribution measurement using a laser diffraction / scattering type particle size distribution measuring device (LA-920, manufactured by Horiba, Ltd.) and ethanol (95) (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) as a dispersion medium, and the arithmetic mean diameter was recorded as the average particle size (μm). Based on the particle size distribution measurement results, the volume ratio of particles of 50 μm or less in the hydraulic powder and the volume ratio of particles of 20 μm or less in the hydraulic powder were calculated. The results are shown in Table 1. In this example, the larger the average particle size of the hydraulic powder, the more the microparticulation of the (B) component is suppressed. Also, the smaller the volume ratio of particles of 50 μm or less or 20 μm or less in the hydraulic powder, the more the microparticulation of the hydraulic powder is suppressed. In other words, the (A) component, the (B-1) component, and the (B-2) component contain a certain amount of particles with a particle size of 50 μm or more, and the degree of microparticulation of the hydraulic powder can be estimated by evaluating the volume ratio of the particles.

[0076] [Table 1]

[0077] In Table 1, the atomization of the blended cement was suppressed in Example 1-1 compared to Comparative Example 1-1. This is believed to be because the (C) component acts electrostatically on the cationite on the surface of the (B) component while not excessively lowering the surface tension of the bound water, thereby covering and protecting the surface of the (B) component, thereby suppressing the atomization of the (B) component. In addition, in Table 1, in Examples 1-2 to 1-4, the atomization of the blended cement was further suppressed compared to Examples 1-9 to 1-10. This is believed to be because the specific (C) component electrostatically acts on the cationite on the surface of the (B) component while not excessively lowering the surface tension of the bound water, thereby covering and protecting the surface of the (B) component, thereby further suppressing the atomization of the (B) component.

Claims

1. A method for producing a hydraulic powder, comprising mixing the following component (B) with the following component (C), and mixing or stirring the mixture of components (B) and (C) obtained by mixing with the following component (A). (A) Component: Cement clinker or cement powder (B) Component: one or more selected from minerals, slag, and ash, containing less than 2.0% by mass of iron in terms of iron oxide and having a Mohs hardness of 1 or more and 5 or less. Component (C): a compound represented by the following general formula (c1) or a salt thereof 【Chemistry 1】 [In the formula, R １ｃ represents a hydrogen atom, a hydrocarbon group having from 1 to 4 carbon atoms, a hydroxyalkyl group having from 2 to 4 carbon atoms, or a polar functional group having from 4 to 10 carbon atoms, and each AO independently represents an alkylene oxide having from 2 to 4 carbon atoms.

2. A method for producing a hydraulic powder, comprising mixing the following component (A) with the following component (C), and mixing or stirring the mixture of components (A) and (C) obtained by mixing with the following component (B). (A) Component: Cement clinker or cement powder (B) Component: one or more selected from minerals, slag, and ash, containing less than 2.0% by mass of iron in terms of iron oxide and having a Mohs hardness of 1 or more and 5 or less. Component (C): a compound represented by the following general formula (c1) or a salt thereof 【Chemistry 2】 [In the formula, R １ｃ represents a hydrogen atom, a hydrocarbon group having from 1 to 4 carbon atoms, a hydroxyalkyl group having from 2 to 4 carbon atoms, or a polar functional group having from 4 to 10 carbon atoms, and each AO independently represents an alkylene oxide having from 2 to 4 carbon atoms.

3. In the general formula (c1), R １ｃ The method for producing hydraulic powder according to claim 1 or 2, wherein represents a hydrogen atom or a polar functional group having 4 to 10 carbon atoms.

4. 3. The method for producing a hydraulic powder according to claim 1, wherein a mass ratio (aB) / (aA) of an adsorption amount (aA) of the component (C) to the component (A) and an adsorption amount (aB) of the component (C) to the component (B) is 1.0 or more.

5. 3. The method for producing a hydraulic powder according to claim 1, wherein the component (C) is mixed in an amount of 0.005 parts by mass or more and 0.5 parts by mass or less per 100 parts by mass of the total amount of the components (A) and (B).

6. 3. The method for producing a hydraulic powder according to claim 1, wherein the component (A) and the component (B) are mixed so that the mass ratio ((A) / (B)) of the amount of the component (A) mixed to the amount of the component (B) mixed is 1 or more and 99 or less.

7. The method for producing hydraulic powder according to claim 1 or 2, wherein the mixing amount of the component (A) relative to the hydraulic powder is 50% by mass or more and 99% by mass or less.

8. 3. The method for producing a hydraulic powder according to claim 1, wherein the component (B) comprises at least one selected from calcium carbonate, kaolin, and dolomite.

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