JP6676355B2 - Hydraulic composition - Google Patents

Description

  The present invention relates to a hydraulic powder composition comprising cement clinker, gypsum and inorganic powder. Specifically, the present invention relates to a hydraulic powder composition whose color tone is adjusted by including an inorganic powder.

The cement industry is a mass production and mass consumption type industry, and resource saving and energy saving are the most important issues. For example, the most mass-produced Portland cement requires that raw materials adjusted to a predetermined chemical composition be fired at a high temperature of 1450 ° C. to 1550 ° C. to produce clinker. It is. That is, if the firing temperature of the clinker can be reduced, energy can be reduced. The firing temperature reduction of clinker technique for increasing the _C 4 AF is the main mineral clinker _{(4CaO · Al 2 O 3 ·} Fe 2 O 3) has been developed. (Patent Document 1)
On the other hand, effective use of waste and by-products has become an important issue in connection with recent global environmental problems. It is considered effective to effectively utilize or treat waste as a raw material or fuel at the time of cement production by making use of the features of the cement industry and cement production equipment from the viewpoint of safe and mass disposal. Most of wastes and by-products have a high content of Al ₂ O ₃ , and in the above-mentioned system for increasing C ₄ AF, the Al ₂ O ₃ content of the cement clinker is higher than that of the conventional Portland cement clinker. In addition, more waste and by-products can be used than conventional Portland cement clinker. Also in this respect, the clinker described in Patent Document 1 is excellent.

Patent No. 5665638

Since the cement clinker described in the patent document can be fired at a low temperature, C ₄ AF is increased, and the Fe ₂ O ₃ content in the cement clinker is increased. Due to the increase in Fe ₂ O ₃ , the color tone of the cement produced from the cement clinker is changed as compared with the conventional Portland cement, and the L value tends to decrease. When the color tone changes from the conventional Portland cement, it is expected that the color tone will change only at the relevant portion when used as a repair material or the like, and the use may be restricted from the viewpoint of aesthetic appearance. It is difficult to reduce the color tone of the cement clinker itself to the same level as before without reducing the amount of Fe ₂ O ₃ . When Fe ₂ O ₃ is reduced, baking at a low temperature becomes difficult, and the energy saving effect, which is a major feature of the clinker, cannot be sufficiently obtained.

  Therefore, in the present invention, compared with the conventional Portland cement clinker, it is possible to reduce the sintering temperature at the time of production, and furthermore, to use the conventional Portland cement clinker capable of increasing the amount of waste used. It is an object of the present invention to provide a hydraulic composition having a color tone similar to that of paint.

The present inventors have conducted intensive studies to solve the above problems, and found that by mixing a predetermined amount of inorganic powder with clinker having an increased Fe ₂ O ₃ content, a color tone similar to that of a conventional cement can be obtained. The present invention has been completed.

That is, in the present invention, the total amount of C ₃ A and C ₄ AF calculated by the Borg equation is 22% or more, the C ₃ S amount is 60% or more and 70% or less, and the iron ratio (IM) is 0.8. Hydraulic powder composition comprising 100 parts by mass of cement clinker of ~ 1.3, gypsum of 0.5 to 10 parts by mass, and 26 to 100 parts by mass of inorganic powder having L of 80 or more, wherein L is in the range of 50 to 55. is there.

  According to the present invention, it is possible to sinter at a lower temperature than conventional Portland cement clinker, and even if a clinker capable of increasing the amount of waste and by-products used is used, the hydraulic property is equivalent to Portland cement of a color tone. A composition is obtained.

The C ₃ A, C ₄ AF and C ₃ S amounts in the present invention are determined by the Bogue equation.

  The Borg equation is used along with the coefficients and various ratios, and is a calculation equation for calculating the approximate main compound composition using the main chemical analysis values, and is a formula well known to those skilled in the art. Describes how to determine the amount of each mineral in the clinker using the Borg equation.

C ₃ S content = (4.07 × CaO) - ( 7.60 × SiO 2) - (6.72 × Al 2 O 3) - (1.43 × Fe 2 O 3)
C ₂ S amount = (2.87 × SiO ₂ ) − (0.754 × C ₃ S)
C ₃ A amount = (2.65 × Al ₂ O ₃ ) − (1.69 × Fe ₂ O ₃ )
C ₄ AF amount = 3.04 × Fe ₂ O ₃

  The iron rate (IM) is defined as hydraulic coefficient (HM), silicate rate (SM), activity coefficient (AI), and lime saturation (LSD). Next, it is obtained using the main chemical component value, and is used as one of the number of times and various ratios as a characteristic value for clinker production control, and is a coefficient well known to those skilled in the art, but just in case The method of calculating the iron ratio is described below together with other coefficient values.

Hydraulic modulus (HM) = CaO / (SiO ₂ + Al ₂ O ₃ + Fe ₂ O ₃ )
Silicate ratio _{(S.M.) = SiO 2 / (} Al 2 O 3 + Fe 2 O 3)
Iron ratio _{(I.M.) = Al 2 O 3} / Fe 2 O 3
Activity factor _{(A.I.) = SiO 2 / Al} 2 O 3
Lime saturation (L.S.D.) = CaO / (2.8 × SiO 2 + 1.2 × Al 2 O 3 + 0.65 × Fe 2 O 3)

In the above, “CaO”, “SiO ₂ ”, “Al ₂ O ₃ ” and “Fe ₂ O ₃ ” are JIS R 5202 “Chemical analysis method of Portland cement” and JIS R 5204 “Fluorescent X of cement”, respectively. Line analysis method ".

As described above, in the cement clinker of the present invention, the total amount of C ₃ A and C ₄ AF must be 22% or more. When these amounts are less than 22%, it becomes difficult to obtain a cement clinker having good physical properties such as strength development by firing at a temperature of 1300 to 1400 ° C. A more preferred total amount is 24% or more. In addition, as described later, 60% or more of C ₃ S is required in order to obtain high strength development. Therefore, the upper limit of the total amount of C ₃ A and C ₄ AF is 40%. It is preferably at most 35%, more preferably at most 32%, particularly preferably at most 28%. Of these components, C ₄ AF is preferably present alone by 15% or more in that it can be sufficiently sintered even at a low temperature and the amount of f-CaO in the clinker can be reduced.

The amount of C ₃ S is extremely important for the strength development of a cement composition (hereinafter, simply “cement”) using the cement clinker of the present invention. If this amount is less than 60%, good strength developability cannot be obtained even when the total amount of C ₃ A and C ₄ AF and the iron ratio described below are within predetermined ranges. The C ₃ S content is preferably at least 62%, particularly preferably at least 63%. Since the total amount of C ₃ A and C ₄ AF described above is at least 22%, the upper limit of the amount of C ₃ S is 78%. In order to secure a certain amount of time from the start to the end of the setting, the content is preferably 70% or less, more preferably 65% or less.

The cement clinker of the present invention may further contain C ₂ S. The amount is 18% or less, preferably 3% or more. From the viewpoint of obtaining long-term strength, the amount is particularly preferably an amount that makes the total amount with the C ₃ S amount 69% or more.

  The cement clinker iron ratio (IM) of the present invention is 1.3 or less. If the iron ratio exceeds 1.3, sufficient strength development (more specifically, mortar strength development, for example) cannot be obtained even if other requirements for the cement clinker of the present invention are satisfied. Further, when the iron ratio exceeds 1.3, the time from the start to the end of the setting tends to be too long, and from this point, the iron ratio is set to 1.3 or less. A more preferable range of the iron ratio is 1.0 to 1.3, and particularly preferably 1.14 to 1.27.

  Although the hydraulic modulus and the silicic acid ratio are not particularly limited, the hydraulic modulus is preferably 1.8 to 2.2, and particularly preferably 1.9, in order to achieve an excellent balance of various physical properties. To 2.1, and the silicic acid ratio is preferably 1.0 to 2.0, and particularly preferably 1.1 to 1.7.

  The method for producing the cement clinker used in the present invention is not particularly limited, and a known cement (clinker) raw material is prepared and mixed at a predetermined ratio so as to have the above-mentioned respective mineral ratios and coefficients. It can be obtained by firing by a method (for example, SP kiln or NSP kiln).

A known method may be appropriately adopted as a method for preparing and mixing the cement raw material. For example, pre-waste, by-products and other raw materials (limestone, burnt lime, CaO source such as slaked lime, SiO ₂ source such as silica, _Al 2 _{O 3} source, such as clays, such as _Fe 2 _{O 3} source, an iron source, etc.) May be measured, the blending ratio of each raw material may be calculated from the ratio of each component in these raw materials so as to be within the above range, and the raw materials may be blended at that ratio.

  The raw materials used in the production of cement clinker used in the present invention are the same as those used in the production of conventional cement clinker without any particular limitation. It is of course possible to use waste, by-products, and the like.

  In the production of the cement clinker used in the present invention, it is preferable to use one or more of wastes, by-products, and the like from the viewpoint of promoting effective use of wastes, by-products, and the like. More specific examples of waste and by-products that can be used include blast furnace slag, steelmaking slag, nonferrous slag, coal ash, sewage sludge, purified water sludge, papermaking sludge, construction soil, foundry sand, soot and dust, incineration fly ash, and melting. Fly ash, chlorine bypass dust, wood chips, waste clay, waste, waste tires, shells, municipal waste and incinerated ash, etc. (Some of these can be used as raw materials for cement and also as sources of thermal energy.) is there).

In particular, the cement clinker used in the present invention contains a large amount of C ₃ A and C ₄ AF minerals containing aluminum as a constituent element. Therefore, as compared with the conventional cement clinker, there is an advantage that it can be manufactured using more wastes and by-products having a high aluminum content.

  However, the cement clinker tends to be darker than the conventionally used cement clinker, and usually has an L of less than 50 and often less than 48.

  Therefore, in the hydraulic powder composition of the present invention, in order to adjust the brightness of the composition, an inorganic powder having a lightness L of 80 or more is blended as an essential component in addition to the cement clinker and the gypsum.

The gypsum used is for adjusting the setting time, and gypsum known as a cement production material such as gypsum dihydrate, gypsum hemihydrate, and anhydrous gypsum can be used without any particular limitation. The amount of gypsum added is preferably such that the amount of SO ₃ in the hydraulic composition is 0.5 to 10% by mass, more preferably 1.0 to 5% by mass, An addition amount of 1.8 to 3% by mass is particularly preferable.

  The inorganic powder to be used can be used without particular limitation as long as the lightness L is 80 or more. Preferably, L is from 80 to 95. Specific examples are limestone, blast furnace slag and fly ash. Known limestone, blast furnace slag and fly ash can be used as the cement mixture. Besides, inorganic oxides such as silica, alumina, titania, and zirconia, and wastes such as shell powder can be used.

  The inorganic powder is mixed so that L of the hydraulic powder composition after mixing is in the range of 50 to 55. The amount to be mixed varies in a range of 5 to 100 parts by mass depending on the value of L of the inorganic powder. It is about parts by mass.

The cement clinker, gypsum and inorganic powder are preferably adjusted so that the fineness is 2800 to 4500 cm ² / g in Blaine specific surface area.

  A known technique can be used for the pulverization method for adjusting to the fineness without any particular limitation. Each component may be individually pulverized and then mixed, or pulverized after mixing. As a pulverizer, a ball mill, a vertical mill or the like can be used.

  The hydraulic powder composition of the present invention thus obtained has a color tone equivalent to that of the conventional cement composition, and is not inferior to various physical properties such as curability. Can be used with

  Hereinafter, the configuration and effects of the present invention will be described with reference to examples, but the present invention is not limited to these examples.

Raw materials were prepared using industrial raw materials including waste, and calcined at 1450 ° C. and 1350 ° C. in an electric furnace to obtain cement clinker. Table 1 shows the mineral composition, various ratios and coefficients of the obtained clinker according to the Borg equation. Gypsum was added to the cement clinker so as to have a concentration of 2 ± 0.2% in terms of SO ₃ , mixed and pulverized so that the specific surface area by the Blaine method was 3200 ± 50 cm ² / g, and a cement was trial-produced. Limestone and blast furnace slag pulverized to about 4000 cm ² / g as inorganic powder were mixed with the obtained cement at a predetermined ratio. Table 2 shows the colors of the limestone and blast furnace slag used.

  Table 3 shows the results of the addition ratio of the inorganic powder of the obtained composition and the color tone measured by a spectral colorimeter.

参考例は従来からある標準的な組成のセメントクリンカーを標準的な温度で焼成し、無機粉末を混合せずに石膏のみを添加した場合を示す例である。即ち、各実施例・比較例の結果の良否は、この参考例の結果と基準として論じることになる。

The reference example is an example showing a case where a conventional cement clinker having a standard composition is fired at a standard temperature and only gypsum is added without mixing inorganic powder. That is, the quality of the results of the examples and comparative examples will be discussed as a reference with the results of the reference example.

  Comparative Example 1 is an example showing a case where only gypsum was added to clinker prepared at a predetermined composition and fired at a low temperature. The L value is lower than that of the reference example, and it can be seen that the color tone of the composition has changed.

  Examples 1 to 6 relate to the present invention, and were prepared so as to have a predetermined composition, 100 parts by mass of clinker fired at a low temperature, 4 parts by mass of gypsum, and a total of 26 parts by mass to 45 parts by mass of inorganic powder. This is an example where the components are mixed so as to be parts by mass. The lightness L is in the range of 50 to 55, which is about the same as that of the reference example, and it is understood that the color tone is adjusted to be about the same as that of the reference example as compared with the comparative example 1 in which the inorganic powder is not added. .

  Comparative Examples 2 to 7 were prepared so as to have a predetermined composition and mixed with 100 parts by mass of clinker fired at a low temperature, 4 parts by mass of gypsum, and 5 to 12 parts by mass of inorganic powder in total. Where L is below 50. For this reason, when this composition is used, the cured product is expected to have a dark color.

  Comparative Examples 8 to 13 were prepared so as to have a predetermined composition and mixed with 100 parts by mass of clinker fired at a low temperature, 4 parts by mass of gypsum and 69 parts by mass to 416 parts by mass of inorganic powder in total. It is. It can be seen that L exceeds 55 and is considerably higher than that of the reference example. For this reason, when this composition is used, the cured product is expected to be too bright.

Claims (2)

The total amount of _{C 3} A and _C 4 AF is calculated by Borg type 22% or more, _{C 3} S content is 70% 60% or less, iron ratio (i.m.) is 0.8 to 1.3 A hydraulic powder composition comprising 100 parts by mass of cement clinker, 0.5 to 10 parts by mass of gypsum, 26 to 100 parts by mass of an inorganic powder having L of 80 or more, and L in the range of 50 to 55. The total amount of _{C 3} A and _C 4 AF is calculated by Borg type 22% or more, _{C 3} S content is 70% 60% or less, iron ratio (i.m.) is 0.8 to 1.3 Gypsum 0.5 to 10 parts by mass and L to the inorganic powder of 80 or more with respect to 100 parts by mass of the cement clinker, and 26 to 100 parts by mass such that L of the powder composition after addition is in the range of 50 to 55. The method for producing a hydraulic powder composition of which the brightness is adjusted in the range described above.