SG193341A1 - Cement compositions and process for producing same - Google Patents
Cement compositions and process for producing same Download PDFInfo
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- SG193341A1 SG193341A1 SG2013067160A SG2013067160A SG193341A1 SG 193341 A1 SG193341 A1 SG 193341A1 SG 2013067160 A SG2013067160 A SG 2013067160A SG 2013067160 A SG2013067160 A SG 2013067160A SG 193341 A1 SG193341 A1 SG 193341A1
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- 239000004568 cement Substances 0.000 title claims abstract description 258
- 239000000203 mixture Substances 0.000 title claims abstract description 142
- 238000000034 method Methods 0.000 title claims abstract description 19
- 239000002994 raw material Substances 0.000 claims abstract description 76
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims abstract description 43
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims abstract description 38
- 239000002893 slag Substances 0.000 claims abstract description 35
- 239000002689 soil Substances 0.000 claims abstract description 24
- 235000019738 Limestone Nutrition 0.000 claims abstract description 23
- 239000006028 limestone Substances 0.000 claims abstract description 23
- 238000004519 manufacturing process Methods 0.000 claims abstract description 23
- 239000010883 coal ash Substances 0.000 claims abstract description 21
- 238000010276 construction Methods 0.000 claims abstract description 21
- 229910052742 iron Inorganic materials 0.000 claims abstract description 20
- 239000010801 sewage sludge Substances 0.000 claims abstract description 19
- 239000000377 silicon dioxide Substances 0.000 claims abstract description 19
- 238000001354 calcination Methods 0.000 claims abstract description 18
- 239000004927 clay Substances 0.000 claims abstract description 17
- 239000010440 gypsum Substances 0.000 claims abstract description 15
- 229910052602 gypsum Inorganic materials 0.000 claims abstract description 15
- 238000010298 pulverizing process Methods 0.000 claims abstract description 13
- 239000000654 additive Substances 0.000 claims abstract description 11
- 230000000996 additive effect Effects 0.000 claims abstract description 11
- 239000000463 material Substances 0.000 claims abstract description 11
- 239000004570 mortar (masonry) Substances 0.000 abstract description 28
- 230000001747 exhibiting effect Effects 0.000 abstract description 26
- CPLXHLVBOLITMK-UHFFFAOYSA-N Magnesium oxide Chemical compound [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 description 50
- 239000000395 magnesium oxide Substances 0.000 description 25
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 23
- 239000000047 product Substances 0.000 description 15
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 12
- 229910052802 copper Inorganic materials 0.000 description 12
- 239000010949 copper Substances 0.000 description 12
- 239000000428 dust Substances 0.000 description 12
- 239000011573 trace mineral Substances 0.000 description 7
- 235000013619 trace mineral Nutrition 0.000 description 7
- 230000000052 comparative effect Effects 0.000 description 6
- 229910052500 inorganic mineral Inorganic materials 0.000 description 6
- 235000010755 mineral Nutrition 0.000 description 6
- 239000011707 mineral Substances 0.000 description 6
- 239000011398 Portland cement Substances 0.000 description 5
- 238000001479 atomic absorption spectroscopy Methods 0.000 description 5
- 238000009614 chemical analysis method Methods 0.000 description 5
- 238000004993 emission spectroscopy Methods 0.000 description 5
- 238000004445 quantitative analysis Methods 0.000 description 5
- 238000007655 standard test method Methods 0.000 description 5
- 241001504564 Boops boops Species 0.000 description 3
- 238000001816 cooling Methods 0.000 description 3
- 150000004683 dihydrates Chemical class 0.000 description 3
- 239000010881 fly ash Substances 0.000 description 3
- -1 hydrocake Substances 0.000 description 3
- 238000002156 mixing Methods 0.000 description 3
- 229910052750 molybdenum Inorganic materials 0.000 description 3
- 239000011369 resultant mixture Substances 0.000 description 3
- 239000013535 sea water Substances 0.000 description 3
- 229910052712 strontium Inorganic materials 0.000 description 3
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 2
- 239000002956 ash Substances 0.000 description 2
- 238000013031 physical testing Methods 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- 239000010802 sludge Substances 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 229910052720 vanadium Inorganic materials 0.000 description 2
- LEONUFNNVUYDNQ-UHFFFAOYSA-N vanadium atom Chemical compound [V] LEONUFNNVUYDNQ-UHFFFAOYSA-N 0.000 description 2
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 1
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 description 1
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 1
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 description 1
- 238000002441 X-ray diffraction Methods 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 150000004645 aluminates Chemical class 0.000 description 1
- 239000011400 blast furnace cement Substances 0.000 description 1
- 239000010882 bottom ash Substances 0.000 description 1
- 239000006227 byproduct Substances 0.000 description 1
- 229910052791 calcium Inorganic materials 0.000 description 1
- 239000011575 calcium Substances 0.000 description 1
- AXCZMVOFGPJBDE-UHFFFAOYSA-L calcium dihydroxide Chemical compound [OH-].[OH-].[Ca+2] AXCZMVOFGPJBDE-UHFFFAOYSA-L 0.000 description 1
- 239000000920 calcium hydroxide Substances 0.000 description 1
- 229910001861 calcium hydroxide Inorganic materials 0.000 description 1
- 235000012241 calcium silicate Nutrition 0.000 description 1
- JHLNERQLKQQLRZ-UHFFFAOYSA-N calcium silicate Chemical compound [Ca+2].[Ca+2].[O-][Si]([O-])([O-])[O-] JHLNERQLKQQLRZ-UHFFFAOYSA-N 0.000 description 1
- 229910052918 calcium silicate Inorganic materials 0.000 description 1
- OSGAYBCDTDRGGQ-UHFFFAOYSA-L calcium sulfate Chemical compound [Ca+2].[O-]S([O-])(=O)=O OSGAYBCDTDRGGQ-UHFFFAOYSA-L 0.000 description 1
- ZOMBKNNSYQHRCA-UHFFFAOYSA-J calcium sulfate hemihydrate Chemical compound O.[Ca+2].[Ca+2].[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O ZOMBKNNSYQHRCA-UHFFFAOYSA-J 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 239000003818 cinder Substances 0.000 description 1
- 239000003245 coal Substances 0.000 description 1
- 238000006114 decarboxylation reaction Methods 0.000 description 1
- BCAARMUWIRURQS-UHFFFAOYSA-N dicalcium;oxocalcium;silicate Chemical compound [Ca+2].[Ca+2].[Ca]=O.[O-][Si]([O-])([O-])[O-] BCAARMUWIRURQS-UHFFFAOYSA-N 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 description 1
- 238000004898 kneading Methods 0.000 description 1
- 229910052749 magnesium Inorganic materials 0.000 description 1
- 239000011777 magnesium Substances 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
- 239000011733 molybdenum Substances 0.000 description 1
- 229910052762 osmium Inorganic materials 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 238000003908 quality control method Methods 0.000 description 1
- CIOAGBVUUVVLOB-UHFFFAOYSA-N strontium atom Chemical compound [Sr] CIOAGBVUUVVLOB-UHFFFAOYSA-N 0.000 description 1
- 239000000725 suspension Substances 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
- 229910000859 α-Fe Inorganic materials 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B7/00—Hydraulic cements
- C04B7/24—Cements from oil shales, residues or waste other than slag
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B7/00—Hydraulic cements
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B7/00—Hydraulic cements
- C04B7/02—Portland cement
- C04B7/06—Portland cement using alkaline raw materials
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B7/00—Hydraulic cements
- C04B7/14—Cements containing slag
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B7/00—Hydraulic cements
- C04B7/14—Cements containing slag
- C04B7/147—Metallurgical slag
- C04B7/153—Mixtures thereof with other inorganic cementitious materials or other activators
- C04B7/17—Mixtures thereof with other inorganic cementitious materials or other activators with calcium oxide containing activators
- C04B7/19—Portland cements
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B7/00—Hydraulic cements
- C04B7/24—Cements from oil shales, residues or waste other than slag
- C04B7/26—Cements from oil shales, residues or waste other than slag from raw materials containing flue dust, i.e. fly ash
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B7/00—Hydraulic cements
- C04B7/24—Cements from oil shales, residues or waste other than slag
- C04B7/28—Cements from oil shales, residues or waste other than slag from combustion residues, e.g. ashes or slags from waste incineration
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B7/00—Hydraulic cements
- C04B7/345—Hydraulic cements not provided for in one of the groups C04B7/02 - C04B7/34
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B7/00—Hydraulic cements
- C04B7/36—Manufacture of hydraulic cements in general
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P40/00—Technologies relating to the processing of minerals
- Y02P40/10—Production of cement, e.g. improving or optimising the production methods; Cement grinding
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Ceramic Engineering (AREA)
- Materials Engineering (AREA)
- Structural Engineering (AREA)
- Organic Chemistry (AREA)
- Combustion & Propulsion (AREA)
- Inorganic Chemistry (AREA)
- Curing Cements, Concrete, And Artificial Stone (AREA)
- Processing Of Solid Wastes (AREA)
Abstract
Provided are a cement composition which maintains and improves the strength exhibiting properties of a cement paste, mortar, or concrete while maintaining5 the fresh properties of the cement paste, mortar, or concrete, and a method for producing the same.A cement composition having a V content of 0.0063 to 0.012% by mass. The cement composition having a Sr content of 0.035 to 0.08% by mass. A method for producing a cement composition, wherein the method comprises the steps of: (A)10 controlling the raw material unit consumption of a raw material for cement clinker selected from the group consisting of limestone, silica, coal ash, clay, blast furnace slag, soil generated by construction, sewage sludge, a hydrocake, and an iron source so that the resultant cement composition has a V content of 0.0063 to 0.012% by mass, and subjecting the raw material having the controlled unit consumption to calcination to15 produce a cement clinker; and (B) pulverizing the produced cement clinker, together with gypsum and an additive material.
Description
CEMENT COMPOSITION AND METHOD FOR PRODUCING THE SAME
[0001] The present invention relates to a cement composition and a method for producing the same.
[0002] A cement composition causes the components contained in the cement composition to react with water to form a hydrate, exhibiting a strength. Generally, the larger the amount of the formed hydrate, the higher the strength of a mortar or concrete.
[0003] The cement users have demanded a cement composition from which a concrete having excellent strength exhibiting properties can be obtained without sacrificing the fluidity or setting time of the concrete.
[0004] As a method for improving the strength exhibiting properties of concrete, e.g., a method of “increasing the fineness (Blaine specific surface area)” or “increasing the
CsS content” is used (for example, non-patent document 1).
PRIOR ART REFERENCE
Non-patent Document
[0005] Non-patent document 1: Japan Cement Association, Common knowledge of cement, “4. Types and uses of cement”, p. 11 to 17, published in 2004
Problems to be Solved by the Invention
[0006] However, when the strength exhibiting properties of a cured product of concrete or the like are improved by a method for changing the fineness or mineral composition of a cement composition, such as the method of “increasing the fineness (Blaine specific surface area)” or “increasing the C3S content” described in non-patent document 1, there are problems in that the setting time is reduced and the fluidity is lowered. Further, the “increasing the fineness” increases the pulverization energy for cement, and the “increasing the CsS content” increases the unit consumption of limestone as a raw material, leading to CO, emission due to decarboxylation of limestone and an increase of the energy for clinker calcination. In any of these cases,
“0 the amount of CO; generated in the production of cement is increased, and this is not preferred from an environmental point of view.
[0007] In view of the above problems, the present invention has been made, and an object of the present invention is to provide a cement composition which can improve the strength exhibiting properties of a cured product of, e.g., a mortar or concrete while maintaining appropriate fresh properties (the amount of water required for nomal consistency of cement paste , setting time) of the mortar or concrete, and a method for producing the same.
Means to Solve the Problems
[0008] The present inventors have conducted extensive and intensive studies with a view toward achieving the above object. As a result, it has been found that for improving the strength exhibiting properties of a cured product of, e.g., a mortar or concrete while maintaining the fresh properties of the mortar or concrete, controlling the vanadium (V) content of the cement composition is effective, and the present invention has been completed.
[0009] Specifically, the present invention is directed to a cement composition having a V content of 0.0063 to 0.012% by mass. The present invention is directed to the cement composition which has a Sr content of 0.035 to 0.08% by mass. The present invention is directed to the cement composition which has a Mo content of 0.0002 to 0.007% by mass and a MgO content of 1 to 3% by mass. The present invention is directed to the cement composition which is obtainable by using a cement clinker having a SO; content of 0.2 to 1.2% by mass. The present invention is directed to the cement composition which has a SO; content of 1.6 to 2.5% by mass. The present invention is directed to the cement composition which has an R,0 content of 0.3 to 0.6% by mass. The present invention is directed to the cement composition which has a C3S content of 45 to 70% by mass, a C,S content of 5 to 25% by mass, a C3A content of 6 to 15% by mass, and a C4AF content of 7 to 15% by mass.
[0010] The present invention is directed to a method for producing a cement composition, wherein the method comprises the steps of: (A) controlling the raw material unit consumption of a raw material for cement clinker selected from the group consisting of limestone, silica, coal ash, clay, blast furnace slag, soil generated by construction, sewage sludge, a hydrocake, and an iron source so that the resultant cement composition has a V content of 0.0063 to 0.012% by mass, and subjecting the raw material having the controlled unit consumption to calcination to produce a cement clinker; and (B) pulverizing the produced cement clinker, together with gypsum and an additive material.
[0011] In the present invention, there can be provided a cement composition which can maintain and improve the strength exhibiting properties of a cured product (for example, strength exhibiting properties of a cured product having an age of 28 days) of a cement paste, mortar, or concrete while maintaining the amount of water required for normal consistency of cement paste (water amount required to obtain a constant softness) and setting time of the cement paste for maintaining appropriate fresh properties of the cement paste, mortar, or concrete, and a method for producing the same.
[0012] [Fig. 1] A graph showing the relationship between the V content of a cement composition and the compressive strength of a mortar (cured product) using the cement composition ‘and having an age of 28 days.
[0013] Hereinbelow, preferred embodiments of the present invention will be described.
[0014] The cement composition according to the present embodiment has a V content of 0.0063 to 0.012% by mass.
[0015] Vanadium (V) is a trace element component contained in the cement composition. The present inventors have found that the V content of the cement composition strongly affects the strength exhibiting properties of a cured product of a cement paste, mortar, or concrete using the cement composition, and that when the V content of the cement composition falls in the appropriate range, the strength exhibiting properties of a cured product of a cement paste, mortar, or concrete using the cement composition can be improved while maintaining appropriate fresh properties (the amount of water required for normal consistency of cement paste, setting time) of the cement paste, mortar, or concrete. The V content of the cement composition is the amount (% by mass) of the V contained, based on the mass of the cement composition, and this amount can be measured in accordance with Japan Cement Association standard test method JCAS 1-52 2000 “Quantitative determination method for trace element components of cement by ICP emission spectrometry and electrothermal type atomic absorption spectrometry”.
[0016] The V content of the cement composition is 0.0063 to 0.012% by mass, preferably 0.0070 to 0.012% by mass, more preferably 0.0080 to 0.0115% by mass, further preferably 0.0090 to 0.0105% by mass. When the V content of the cement composition is less than 0.063% by mass or more than 0.012% by mass, it may be difficult to appropriately maintain the strength exhibiting properties of a cured product of, e.g., a mortar or concrete using the cement composition according to the present embodiment. f0017] The cement composition according to the present embodiment preferably has a strontium (Sr) content of 0.035 to 0.08% by mass, more preferably a Sr content of 0.04 to 0.075% by mass, further preferably 0.041 to 0.07% by mass, especially preferably 0.042 to 0.06% by mass. When the Sr content of the cement composition falls in the above-mentioned range, the strength exhibiting properties of a cured product of, e.g., a mortar or concrete can be maintained and improved while maintaining appropriate fresh properties (the amount of water required for normal consistency of cement paste, setting time) of the cement composition. The Sr content of the cement composition is the amount (% by mass) of the Sr contained, based on the mass of the cement composition, and this amount can be measured in accordance with Japan
Cement Association standard test method JCAS 1-52 2000 “Quantitative determination method for trace element components of cement by ICP emission spectrometry and electrothermal type atomic absorption spectrometry”.
[0018] The cement composition according to the present embodiment preferably has a molybdenum (Mo) content of 0.0002 to 0.007% by mass, more preferably 0.0002 to 0.0065% by mass, further preferably 0.0002 to 0.0064% by mass, especially preferably 0.0002 to 0.0063% by mass. When the Mo content of the cement composition fails in the above-mentioned range, the strength exhibiting properties of a cured product of, e.g., a mortar or concrete can be maintained and improved while maintaining appropriate fresh properties (the amount of water required for normal consistency of cement paste , setting time) of the cement composition. The Mo content of the cement composition is the amount (% by mass) of the Mo contained, based on the mass of the cement composition, and this amount can be measured in accordance with Japan Cement
Association standard test method JCAS 1-52 2000 “Quantitative determination method for trace element components of cement by ICP emission spectrometry and electrothermal type atomic absorption spectrometry”.
[0019] The cement composition according to the present embodiment preferably has aMgO content of 1 to 3% by mass, more preferably 1 to 2.5% by mass, further preferably 1 to 2% by mass, especially preferably 1 to 1.5% by mass. When the MgO content of the cement composition falls in the above-mentioned range, the strength exhibiting properties of a cured product of, e.g., a mortar or concrete can be further improved while maintaining appropriate fresh properties (the amount of water required for normal consistency of cement paste, setting time) of the cement composition. The
MgO content of the cement composition is the amount (% by mass) of the MgO contained, based on the mass of the cement composition, and this amount can be measured in accordance with JIS R 5202: 1998 “Chemical analysis methods for
Portland cement”.
[0020] The cement composition according to the present embodiment is preferably obtainable by using a cement clinker having a SO; content of 0.2 to 1.2 % by mass.
The SO; content of the cement clinker is more preferably 0.25 to 0.90% by mass, further preferably 0.3 to 0.70% by mass. When the SO; content of the cement clinker falls in the above-mentioned range, with respect to the cement composition obtained by pulverizing the cement clinker, together with gypsum and an additive material, it is easy to control the SO; content in a predetermined range.
[0021] Further, the cement composition according to the present embodiment preferably has an R,O content of 0.3 to 0.6% by mass, more preferably 0.35 to 0.6% by mass, further preferably 0.35 to 0.55% by mass, especially preferably 0.4 to 0.5% by mass. When the R,O content of the cement composition falls in the above-mentioned range, the strength exhibiting properties of a cured product of, e.g., a mortar or concrete can be maintained and improved while maintaining appropriate fresh properties (the amount of water required for normal consistency of cement paste, setting time) of the cement composition. The R,O content of the cement composition is the amount (% by mass) of the RO contained, based on the mass of the cement composition, and this amount can be measured in accordance with JIS R 5202: 1998 “Chemical analysis methods for Portland cement”. The R,O (total alkali) content of the cement composition means an amount represented by the following formula (I).
R,0 Content of the cement composition = Na,;0 Content + 0.658 x K,O Content 0
[0022] Further, the cement composition according to the present embodiment preferably has a SO; content of 1.6 to 2.5% by mass, more preferably 1.7 to 2.5% by mass, further preferably 1.8 to 2.48% by mass. When the SO; content of the cement composition falls in the above-mentioned range, the strength exhibiting properties of a cured product of, e.g., a mortar or concrete can be maintained and improved while maintaining appropriate fresh properties (the amount of water required for normal consistency of cement paste, setting time) of the cement composition. The SO; content of the cement composition is the amount (% by mass) of the SO; contained, based on the mass of the cement composition, and this amount can be measured in accordance with JIS R 5202: 1998 “Chemical analysis methods for Portland cement”.
[0023] With respect to the mineral composition of the cement composition according to the present embodiment, it is preferred that the CS content is 45 to 70% by mass, the
C,S content is 5 to 25% by mass, the C3A content is 6 to 15% by mass, and the C4AF content is 7 to 15% by mass, it is more preferred that the C3;S content is 48 to 65% by mass, the C,S content is 10 to 25% by mass, the C3A content is 8 to 13% by mass, and the C4AF content is 8 to 12% by mass, it is further preferred that the C;S content is 50 to 64% by mass, the C;S content is 11 to 20% by mass, the CsA content is 9 to 12% by mass, and the C;AF content is 8 to 11% by mass, and it is especially preferred that the
CS content is 53 to 60% by mass, the C,S content is 11 to 18% by mass, the C3A content is 9 to 11% by mass, and the C4AF content is 8 to 10% by mass. When the mineral composition of the cement composition falls in the above-mentioned range, the strength exhibiting properties of a cured product of, e.g., a mortar or concrete can be easily maintained and improved while maintaining the fresh properties (the amount of water required for normal consistency of cement paste, setting time) of the mortar and concrete.
[0024] The CsS content (alite phase), C,S content (belite phase), C;A content (aluminate phase), and C4AF content (ferrite phase) of the cement composition are determined from the following Bogue equations [1] to [4].
[0025]
CsS Content (% by mass) = 4.07 x CaO Content (% by mass) - 7.60 x SiO; Content (% by mass) - 6.72 x Al,O; Content (% by mass) - 1.43 x Fe,O; Content (% by mass) - 2.85 x SO; Content (% by mass) [1]
C,S Content (% by mass) = 2.87 x SiO; Content (% by mass) - 0.754 x C35 Content (% by mass)
[2] } CsA Content (% by mass) = 2.65 x Al,O; Content (% by mass) - 1.69 x Fe;03 Content (% by mass)
C4AF Content (% by mass) = 3.04 x Fe;03 Content (% by mass) [4]
[0026] In the formulae above, the “CaO Content”, “SiO, Content”, “Al,03 Content”, and “Fe,O3 Content” are the respective amounts (% by mass) of the CaO, SiO, ALL,Os, and Fe;04 contained, based on the mass of the cement composition. These amounts can be measured by JIS R 5202 “Chemical analysis methods for Portland cement” or
JIS R 5204 “Fluorescent X-ray analysis method for cement”.
[0027] Next, the method for producing a cement composition according to an embodiment of the present invention will be described.
The method for producing a cement composition according to the present embodiment comprises the steps of: (A) controlling the raw material unit consumption of a raw material for cement clinker selected from the group consisting of limestone, silica, coal ash, clay, blast furnace slag, soil generated by construction, sewage sludge, a hydrocake, and an iron source (such as copper slag or blast furnace dust) so that the resultant cement composition has a V content of 0.0063 to 0.012% by mass, and subjecting the raw material having the controlled unit consumption to calcination to produce a cement clinker; and (B) pulverizing the produced cement clinker, together with gypsum and an additive material.
[0028] Examples of the raw materials for cement clinker in step (A) include limestone, silica, coal ash, clay, blast furnace slag, soil generated by construction, sewage sludge, a hydrocake, and an iron source. The coal ash is generated from, e.g., a coal fired power plant, and examples include cinder ash, fly ash, clinker ash, and bottom ash. Examples of soil generated by construction include residue soil, mud soil, and waste soil which are secondarily generated by laying operations for construction.
Examples of sewage sludge include sludge itself and dry powder obtained by adding limestone to sludge and drying the resultant mixture, and incineration residue. The hydrocake is a by-product caused when producing a sea water magnesia clinker in the step of adding a small amount of calcium hydroxide to sea water to remove carbon dioxide gas from the sea water, and examples include hydrocakes comprised mainly of calcium, magnesium, or a hydroxide or carbonate thereof. Examples of iron sources include copper slag and blast furnace dust. Any raw materials other than the above- mentioned limestone, silica, coal ash, clay, blast furnace slag, soil generated by construction, sewage sludge, hydrocake, and iron source may be used as long as they contain V in a certain amount.
[0029] With respect to the raw material unit consumption of the raw materials for cement clinker in step (A), it is preferred that 700 to 1,400 kg/t-clinker of limestone, 20 to 150 kg/t-clinker of silica, 0 to 300 kg/t-clinker of coal ash, 0 to 100 kg/t-clinker of clay, 0 to 100 kg/t-clinker of blast furnace slag, 10 to 150 kg/t-clinker of soil generated by construction, 0 to 100 kg/t-clinker of sewage sludge, 0 to 100 kg/t-clinker of a hydrocake, and 30 to 80 kg/t-clinker of an iron source are used on a dry basis (in the state in which no moisture is contained) per 1 ton (t) of the cement clinker. Further, it is more preferred that, as the raw materials for cement clinker in step (A), 800 to 1,300 kg/t-clinker of limestone, 20 to 100 kg/t-clinker of silica, 10 to 250 kg/t-clinker of coal ash, 0 to 80 kg/t-clinker of clay, 5 to 50 kg/t-clinker of blast furnace slag, 20 to 150 kg/t-clinker of soil generated by construction, 0 to 70 kg/t-clinker of sewage sludge, 20 to 80 kg/t-clinker of a hydrocake, and 30 to 60 kg/t-clinker of an iron source are used on a dry basis. It is further preferred that the amount of the coal ash is 20 to 250 kg/t- clinker on a dry basis.
[0030] A method for controlling the raw material unit consumption of the raw material for cement clinker in step (A) is in which a V content of each raw material for cement clinker is measured, and the raw material unit consumption of the cement clinker raw material containing V in a large amount is mainly adjusted, controlling the raw material unit consumption so that the resultant cement composition has a V content of 0.0063 to 0.012% by mass. As an example of the method for controlling the raw material unit consumption of the raw material for cement clinker, there can be mentioned, specifically, a method in which a sample of the cement composition produced in advance is taken and a V content of the cement composition is measured, and the raw material unit consumption of the raw materials for cement clinker is controlled so that the V content of the cement composition becomes 0.0063 to 0.012% by mass, and a cement clinker obtained by subjecting the resultant raw materials to calcination is used. By the above-mentioned method, a cement composition having a
V content in a specific range and having the maintained and improved strength exhibiting properties (for example, strength exhibiting properties for 28-day age) can be produced. The term “raw material unit consumption” means a mass of each raw material used for producing 1 ton of the cement clinker (kg/t-clinker). Any raw materials other than the above-mentioned limestone, silica, coal ash, clay, blast furnace slag, soil generated by construction, sewage sludge, hydrocake, and iron source may be used as long as they contain V in a certain amount.
[0031] Among the raw materials for cement clinker, the amounts (raw material unit consumption) of the coal ash, soil generated by construction, clay, and iron source {copper slag and blast furnace dust) used strongly affect the V content of the cement composition. For adjusting the V content of the cement composition, it is preferred that the cement composition is produced using a cement clinker having the controlled raw material unit consumption of the above-mentioned raw materials which strongly affect the V content.
[0032] In the method for producing a cement composition according to the present embodiment, it is preferred that the raw material unit consumption of the raw material for cement clinker is controlled so that the resultant cement composition has a Sr content of 0.035 to 0.08% by mass. In the method for producing a cement composition, it is preferred that the raw material unit consumption of the raw material for cement clinker is controlled so that the resultant cement composition has a Mo content of 0.0002 to 0.007% by mass. In the method for producing a cement composition, it is preferred that the raw material unit consumption of the raw material for cement clinker is controlled so that the resultant cement composition has a MgO content of 1 to 3% by mass. Further, in the method for producing a cement composition, it is preferred that the raw material unit consumption of the raw material for cement clinker is controlled so that the resultant cement composition has an R,O content of 0.3 to 0.6% by mass. As an example of the method for controlling the Sr content, Mo content, MgO content, and R,O content of the cement composition, there can be mentioned a method in which a sample of the cement composition produced in advance is taken and a Sr content, a Mo content, a MgO content, and an R;0 content of the cement composition are measured, and the raw material unit consumption of the raw materials for cement clinker is controlled so that the Sr content, Mo content, MgO content, and R,O content of the cement composition become the respective specific amounts, and a cement clinker obtained by subjecting the resultant raw materials to calcination is used. {0033] Inthe method for producing a cement composition according to the present embodiment, it is preferred that the raw material unit consumption of the raw material for cement clinker is controlled so that the cement clinker has a SO; content of 0.2 to 1.2% by mass.
[0034] With respect to the raw materials for cement clinker, it is preferred to use the raw materials each having a V content, a Sr content, a Mo content, a MgO content, and an RO content which fall in their respective ranges shown below. The V content, Sr content, Mo content, MgO content, and RyO content of each raw material are the respective amounts (% by mass) of the V, Sr, Mo, MgQ, and R;0 contained, based on the mass of each raw material (100% by mass).
[0035] The limestone used preferably has a V content of 0.0001 to 0.002% by mass, more preferably 0.0001 to 0.0015% by mass, further preferably 0.0002 to 0.0012% by mass, especially preferably 0.0002 to 0.001% by mass. The limestone used preferably has a Sr content of 0.005 to 0.07% by mass, more preferably 0.005 to 0.06% by mass, further preferably 0.01 to 0.06% by mass, especially preferably 0.015 to 0.055% by mass. The limestone used preferably has a Mo content of 0.002% by mass or less, more preferably 0.001% by mass or less, further preferably 0.0005% by mass or less, especially preferably 0.0003% by mass or less. The limestone used preferably has a
MgO content of 0.1 to 1.5% by mass, more preferably 0.2 to 1.3% by mass, further preferably 0.25 to 1.1% by mass, especially preferably 0.3 to 1.0% by mass. The limestone used preferably has an RO content of 0.05% by mass or less, more preferably 0.001 to 0.04% by mass, further preferably 0.005 to 0.03% by mass, especially preferably 0.005 to 0.02% by mass. {0036] The silica used preferably has a V content of 0.001 to 0.01% by mass, more preferably 0.001 to 0.008% by mass, further preferably 0.002 to 0.007% by mass, especially preferably 0.003 to 0.006% by mass. The silica used preferably has a Sr content of 0.001 to 0.04% by mass, more preferably 0.001 to 0.03% by mass, further preferably 0.001 to 0.025% by mass, especially preferably 0.001 to 0.02% by mass.
The silica used preferably has a Mo content of 0.002% by mass or less, more preferably 0.001% by mass or less, further preferably 0.0005% by mass or less, especially preferably 0.0004% by mass or less. The silica used preferably has a MgO content of 0.05 to 1.0% by mass, more preferably 0.1 to 0.8% by mass, further preferably 0.1 to 0.6% by mass, especially preferably 0.1 to 0.5% by mass. The silica used preferably has an R,0 content of 0.1 to 4.0% by mass, more preferably 0.1 to 3.0% by mass, further preferably 0.3 to 2.5% by mass, especially preferably 0.3 to 2.0% by mass.
[0037] The coal ash used preferably has a V content of 0.01 to 0.1% by mass, more preferably 0.01 to 0.08% by mass, further preferably 0.015 to 0.07% by mass, especially preferably 0.035 to 0.06% by mass. For controlling the V content of the cement composition, it is preferred that coal ash having a V content as large as possible is selected and used. The coal ash used preferably has a Sr content of 0.02 to 0.2% by mass, more preferably 0.02 to 0.15% by mass, further preferably 0.02 to 0.13% by mass, especially preferably 0.02 to 0.12% by mass. The coal ash used preferably has a Mo content of 0.004% by mass or less, more preferably 0.003% by mass or less, further preferably 0.002% by mass or less, especially preferably 0.0015% by mass or less.
The coal ash used preferably has a MgO content of 0.2 to 3.0% by mass, more preferably 0.4 to 3.0% by mass, further preferably 0.4 to 2.5% by mass, especially preferably 0.4 to 2.3% by mass. The coal ash used preferably has an R,0O content of 0.1 to 3.5% by mass, more preferably 0.2 to 3.0% by mass, further preferably 0.3 to
2.5% by mass, especially preferably 0.5 to 2.0% by mass.
[0038] The blast furnace slag used preferably has a V content of 0.001 to 0.02% by mass, more preferably 0.001 to 0.015% by mass, further preferably 0.003 to 0.012% by mass, especially preferably 0.004 to 0.01% by mass. The blast furnace slag used preferably has a Sr content of 0.02 to 0.08% by mass, more preferably 0.02 to 0.07% by mass, further preferably 0.02 to 0.06% by mass, especially preferably 0.02 to 0.05% by mass. The blast furnace slag used preferably has a Mo content of 0.002% by mass or less, more preferably 0.001% by mass or less, further preferably 0.0005% by mass or less, especially preferably 0.0003% by mass or less. The blast furnace slag used preferably has a MgO content of 3.0 to 10% by mass, more preferably 3.0 to 8.0% by mass, further preferably 3.0 to 7.0% by mass, especially preferably 4.0 to 7.0% by mass.
The blast furnace slag used preferably has an R;0 content of 0.02 to 1.0% by mass, more preferably 0.04 to 0.8% by mass, further preferably 0.06 to 0.6% by mass, especially preferably 0.08 to 0.5% by mass. [5 [0039] The clay used preferably has a V content of 0.005 to 0.05% by mass, more preferably 0.005 to 0.03% by mass, further preferably 0.01 to 0.025% by mass, especially preferably 0.015 to 0.02% by mass. The soil used preferably has a Sr content of 0.001 to 0.03% by mass, more preferably 0.003 to 0.025% by mass, further preferably 0.003 to 0.02% by mass, especially preferably 0.004 to 0.015% by mass.
The clay used preferably has a Mo content of 0.002% by mass or less, more preferably 0.001% by mass or less, further preferably 0.0005% by mass or less, especially preferably 0.0004% by mass or less. The clay used preferably has a MgO content of 0.3 to 6.0% by mass, more preferably 0.3 to 5.0% by mass, further preferably 0.3 to 4.0% by mass, especially preferably 0.5 to 4.0% by mass. The clay used preferably has an RyO content of 0.5 to 4.0% by mass, more preferably 0.7 to 3.5% by mass, further preferably 1.0 to 3.0% by mass, especially preferably 1.2 to 2.8% by mass.
[0040] The soil generated by construction used preferably has a V content of 0.0001 to 0.03% by mass, more preferably 0.0001 to 0.025% by mass, further preferably 0.005 to 0.02% by mass, especially preferably 0.007 to 0.02% by mass. The soil generated by construction used preferably has a Sr content of 0.01 to 0.4% by mass, more preferably 0.01 to 0.3% by mass, further preferably 0.01 to 0.2% by mass, especially preferably 0.015 to 0.1% by mass. The soil generated by construction used preferably has a Mo content of 0.002% by mass or less, more preferably 0.001% by mass or less, further preferably 0.0005% by mass or less, especially preferably 0.0004% by mass or less. The soil generated by construction used preferably has a MgO content of 0.5 to 6.0% by mass, more preferably 0.5 to 5.5% by mass, further preferably 1.0 to 5.0% by mass, especially preferably 1.0 to 4.0% by mass. The soil generated by construction used preferably has an RyO content of 0.5 to 4.5% by mass, more preferably 0.7 to 4.0% by mass, further preferably 1.0 to 3.5% by mass, especially preferably 1.2 to 3.0% by mass.
[0041] The sewage sludge used preferably has a V content of 0.0001 to 0.01% by mass, more preferably 0.0001 to 0.007% by mass, further preferably 0.0005 to 0.005% by mass, especially preferably 0.0007 to 0.004% by mass. The sewage sludge used preferably has a Sr content of 0.001 to 0.1% by mass, more preferably 0.001 to 0.07% by mass, further preferably 0.001 to 0.05% by mass, especially preferably 0.001 to 0.04% by mass. The sewage sludge used preferably has a Mo content of 0.002% by mass or less, more preferably 0.0015% by mass or less, further preferably 0.0012% by mass or less, 0.0011% by mass or less. The sewage sludge used preferably has a MgO content of 0.05 to 4.0% by mass, more preferably 0.1 to 4.0% by mass, further preferably 0.1 to 3.0% by mass, especially preferably 0.1 to 2.5% by mass. The sewage sludge used preferably has an R;O content of 0.4 to 3.5% by mass, more preferably 0.6 to 3.0% by mass, further preferably 0.8 to 2.5% by mass, especially preferably 1.0 to 2.0% by mass.
[0042] The hydrocake used preferably has a V content of 0.001 to 0.1% by mass, more preferably 0.01 to 0.08% by mass, further preferably 0.01 to 0.06% by mass, especially preferably 0.01 to 0.05% by mass. The hydrocake used preferably has a Sr content of 0.1 to 0.8% by mass, more preferably 0.1 to 0.7% by mass, further preferably 0.1 to 0.6% by mass, especially preferably 0.1 to 0.5% by mass. The hydrocake used preferably has a Mo content of 0.002% by mass or less, more preferably 0.001% by mass or less, further preferably 0.0005% by mass or less, especially preferably 0.0003%
Dbymassorless. The hydrocake used preferably has a MgO content of 5 to 30% by mass, more preferably 5 to 25% by mass, further preferably 10 to 25% by mass, especially preferably 10 to 20% by mass. The hydrocake used preferably has an R,0 content of 0.02 to 1.5% by mass, more preferably 0.04 to 1.2% by mass, further preferably 0.06 to 1.0% by mass, especially preferably 0.08 to 0.8% by mass.
[0043] The copper slag used as an iron source preferably has a V content of 0.001 to 0.05% by mass, more preferably 0.003 to 0.03% by mass, further preferably 0.005 to 0.03% by mass, especially preferably 0.005 to 0.02% by mass. The copper slag used preferably has a Sr content of 0.005 to 0.05% by mass, more preferably 0.005 to 0.04% by mass, further preferably 0.005 to 0.03% by mass, especially preferably 0.005 to 0.02% bymass. The copper slag used preferably has a Mo content of 0.0002 to 0.8% by mass, more preferably 0.0002 to 0.6% by mass, further preferably 0.0002 to 0.4% by mass, especially preferably 0.0002 to 0.3% by mass. The copper slag used preferably has a MgO content of 0.5 to 3.0% by mass, more preferably 0.5 to 2.5% by mass, further preferably 0.6 to 2.0% by mass, especially preferably 0.7 to 1.5% by mass.
The copper slag used preferably has an R,O content of 0.04 to 2% by mass, more preferably 0.06 to 1.8% by mass, further preferably 0.08 to 1.6% by mass, especially preferably 1 to 1.4% by mass.
[0044] The blast furnace dust used as an iron source preferably has a V content of 0.001 to 0.03% by mass, more preferably 0.003 to 0.02% by mass, further preferably 0.005 to 0.02% by mass, especially preferably 0.008 to 0.015% by mass. The blast furnace dust used preferably has a Sr content of 0.001 to 0.03% by mass, more preferably 0.001 to 0.02% by mass, further preferably 0.002 to 0.015% by mass, especially preferably 0.002 to 0.01% by mass. The blast furnace dust used preferably has a Mo content of 0.004% by mass or less, more preferably 0.003% by mass or less, further preferably 0.002% by mass or less, especially preferably 0.001% by mass or less.
The blast furnace dust used preferably has a MgO content of 0.1 to 3.0% by mass, more preferably 0.15 to 2.0% by mass, further preferably 0.15 to 1.5% by mass, especially preferably 0.2 to 1.5% by mass. The blast furnace dust used preferably has an R,0 content of 0.002 to 1.0% by mass, more preferably 0.004 to 0.8% by mass, further preferably 0.006 to 0.6% by mass, especially preferably 0.008 to 0.4% by mass.
[0045] With respect to the iron source, e.g., converter slag or deironized slag preferably having a V content of 0.05 to 0.5% by mass, more preferably 0.08 to 0.5% by mass, further preferably 0.1 to 0.4% by mass, can be selected and used as a raw material for controlling the V content of the cement composition.
[0046] The production of the cement clinker can be conducted using existing cement production facilities of an SP system (multicyclone preheating system) or an NSP system (multicyclone preheating system using a calcination furnace).
[0047] In the production on an commercial scale, for example, a sample for quality control is taken during the calcination for cement clinker, and a V content of the sample is measured, and, based on the V content of each of the raw materials, the ratio between the raw materials used (raw material unit consumption) is controlled so that the resultant cement clinker has a V content of 0.0063 to 0.012% by mass.
[0048] Next, as one mode of step (A)(calcination step) in the present invention, an example in which a cement clinker is produced using existing cement production facilities of an NSP system is described below.
[0049] With respect to the method for mixing together the raw materials for cement clinker, there is no particular limitation, but it is preferred that the raw materials are pulverized and mixed together by, for example, a raw material pulverizing mill, and further mixed by a blending silo.
[0050] The pulverized and mixed raw materials for cement clinker can be then subjected to calcination using a suspension preheater and a rotary kiln which are existing facilities. The cement clinker having a V content of 0.0063 to 0.012% by mass can be produced also by controlling calcination conditions for cement clinker, such as a calcination temperature or a calcination time.
[0051] With respect to the calcination temperature for the cement clinker, there is no particular limitation, but, when using cement production facilities of an NSP system, the temperature of the cement clinker near the outlet of the rotary kiln is preferably 800 to 1,700°C, more preferably 900 to 1,600°C, further preferably 1,000 to 1,500°C. The calcination time is 20 minutes to 2 hours, more preferably 30 minutes to 2 hours, further preferably 45 minutes to 1.5 hour.
[0052] It is preferred that the cement clinker obtained after the calcination is cooled to, for example, about 100 to 200°C using a clinker cooler provided downstream of the rotary kiln. The cooling rate is preferably 10 to 60 °C/minute, more preferably 15 to 45 °C/minute, further preferably 15 to 30 °C/minute. When the cooling rate is in the range of from 10 to 60 °C/minute, there can be produced a cement clinker from which a cement composition that enables production of a mortar or concrete having excellent strength exhibiting properties can be obtained.
[0053] Next, as one mode of step (B)(pulverizing step) in the present invention, a step for pulverizing the cement clinker together with gypsum and an additive material is described below.
[0054] A cement composition can be produced by mixing together the cement clinker having a V content of 0.0063 to 0.012% by mass and gypsum and pulverizing the resultant mixture. The gypsum desirably satisfies the quality prescribed in JIS R 9151 “Natural gypsum for cement”, and, specifically, dihydrate gypsum, hemihydrate gypsum, or insoluble anhydrous gypsum is preferably used.
[0055] In step (B){(pulverizing step), it is preferred that gypsum is incorporated into the cement clinker having a V content of 0.0063 to 0.012% by mass so that the obtained cement composition has a SO; content of 1.6 to 2.5% by mass, more preferably 1.7 to 2.5% by mass, further preferably 1.8 to 2.48% by mass. With respect to the pulverizing method, there is no particular limitation, and examples include a method using a pulverizer, such as a ball mill, and a classifying apparatus, such as a separator.
Inthe cement composition containing the cement clinker and gypsum, it is preferred that the cement clinker is contained in an amount of 95 to 97% by mass and the gypsum is contained in an amount of 3 to 5% by mass, based on the mass of the cement composition.
[0056] In pulverizing step (B), the cement composition may further contain an additive material. As an additive material, blast furnace slag prescribed in JIS R 5211 “Blast furnace cement”, a silica additive material prescribed in JIS R 5212 “Silica cement”, fly ash prescribed in JIS A 6201 “Fly ash for concrete”, or limestone fine powder can be used. The amount of the total of the additive materials contained (% by mass) is preferably 5% by mass or less, based on the mass of the cement composition.
[0057] The cement composition according to the present embodiment preferably has a Blaine specific surface area of 2,800 to 4,000 cm*/g. When the Blaine specific surface area falls in the above-mentioned range, a mortar or concrete having further excellent strength exhibiting properties can be produced. The Blaine specific surface area of the cement composition is more preferably 3,000 to 3,800 cm?*/g, further preferably 3,000 to 3,500 cm®/g.
[0058] Hereinabove, the preferred embodiments of the present invention have been described, but the present invention is not limited to the above-mentioned embodiments.
[0059] Hereinbelow, the present invention will be described in more detail with reference to the following Examples and Comparative Exampie, which should not be construed as limiting the scope of the present invention.
[0060] (Examples 1 to 4 and Comparative Example 1) [Raw materials for cement clinker]
With respect to the raw materials for cement clinker, a V content of each of limestone, silica, coal ash, clay, blast furnace slag, soil generated by construction, sewage sludge, a hydrocake, and an iron source (copper slag and blast furnace dust) was measured in advance, and the raw material unit consumption of the above-mentioned raw materials was controlled so that the resultant cement clinker had a V content of 0.0063 to 0.012% by mass. Further, the ratio between the raw materials used (raw material unit consumption) was controlled so that the resultant cement clinker had a Sr content of 0.035 to 0.08% by mass, a Mo content of 0.0002 te 0.007% by mass, a MgO content of 1 to 3% by mass, and an R,O content of 0.3 to 0.6% by mass. Further, for controlling the SO; content of the cement composition, dihydrate gypsum was used.
The V content, Sr content, Mo content, MgO content, and R,0 content of the limestone, silica, coal ash, clay, blast furnace slag, soil generated by construction, sewage sludge, hydrocake, and iron source (copper slag and blast furnace dust) used in Examples and
Comparative Example are shown in Table 1. The chemical components and raw material unit consumption shown below are indicated in terms of raw material unit consumption on a dry basis (in the state in which no moisture is contained). Further, in Table 1, the “<0.00025” indicates a Mo content less than of 0.00025% by mass.
[0061] [Table]
Trace element components of each raw material (% by mass) 0.0003 | 0.045 | <0.00025* 0.014 0.0053 | 0.0044 | 0.0004 1.565 0.0403 | 0.106 | 0.0012 [ 0.96 | 1.193
Blast furnace slag 0.0071 | 0.0462 | 0 | 512 | 0414 0.0133 | 0.0138 | 0.0003 2.282
Soil generated by construction | 0.0160 | 0.0272 0.0003 2.931
Sewage sludge 0.0010 | 0.0161 | 0.0011 1.392
Hydrocake 00130 | 0474 | 0 | 1419 | 0.281
Iron source (Copper slag) 0.0070 | 0.0165 0.266 1.007
Iron source (Blast furnace dust) | 0.0100 | 0.0064 0.001 0.190
[0062] The V, Sr, Mo, MgO, and R,O contents of each raw material were measured in accordance with Japan Cement Association standard test method JCAS I-52 2000 “Quantitative determination method for trace element components of cement by ICP emission spectrometry and electrothermal type atomic absorption spectrometry”.
[0063] [Raw materials for cement clinker]
The unit consumption of individual raw materials used as the raw materials for cement clinker was as follows: limestone: 800 to 1,300 kg/t-clinker; silica: 20 to 150 kg/t-clinker; coal ash: 10 to 250 kg/t-clinker; clay: 0 to 100 kg/t-clinker; blast furnace slag: 0 to 100 kg/t-clinker; soil generated by construction: 20 to 150 kg/t-clinker; sewage sludge: 0 to 100 kg/t-clinker; hydrocake: 0 to 100 kg/t-clinker; and iron source: 30 to 80 kg/t-clinker (copper slag: 5 to 50 kg/t-clinker, and blast furnace dust: 25 to 55 kg/t-clinker).
[0064] [Production of a cement clinker]
The above-mentioned raw materials for cement clinker were mixed together, and the mixed raw materials were subjected to calcination using an NSP kiln at a highest temperature of 1,200 to 1,500°C to produce a cement clinker. The temperature of the cement clinker near the outlet of the NSP kiln was 1,000 to 1,500°C. The cement clinker was cooled from 1,000 to 1,400°C to 100 to 200°C at a cooling rate of 10 to 60 °C/minute using a clinker cooler provided downstream of the rotary kiln.
[0065] Dihydrate gypsum was incorporated into the resultant cement clinker so that the obtained cement composition had a SO; content of 2% by mass, and additive materials (limestone and blast furnace slag) were further added thereto in a limestone amount of 4% by mass and in a blast furnace slag amount of 1% by mass, and the resultant mixture was pulverized using a practical mill so that the Blaine specific surface area became 3,100 to 3,400 cm’/g to obtain a cement composition.
[0066] [Chemical components of the cement composition]
With respect to the above-obtained cement composition, the respective amounts (% by mass) of the SiO», Al,04, Fe; 05, CaO, MgO, R,0, and SO; contained and the SOj3 in the clinker, based on the mass of the cement composition, were measured. These amounts were measured in accordance with JIS R 5202: 1998 “Chemical analysis methods for Portland cement”. Further, a Sr content of the cement composition was measured in accordance with Japan Cement Association standard test method JCAS 1-52 2000 “Quantitative determination method for trace element components of cement by ICP emission spectrometry and electrothermal type atomic absorption spectrometry”, and the results are shown in Table 2.
[0067] [Table 2] [ Ceowmes coroner Gm
EES
S50,
Bn T3092 | a9 | 505 [Gas | TT | 5 [196 | 03 [oa | Gow [000
Ewer [3077 | $i | 28 | G0 | 0 [as | 19 | os | wow | ows | ows example 1
[0068] [Mineral composition and physical properties of the cement composition] <Mineral composition of the cement composition>
The mineral composition (C3S content, C,S content, C3A content, and C4AF content) of the above-obtained cement composition was measured based on the Bogue equations [1] to [4]. The results are shown in Table 3. <Fineness properties of the cement composition>
Fineness properties of cement (Blaine specific surface area and 45 um residue) were measured in accordance with JIS R 5201: 1997 “Physical testing methods for cement”. The results are shown in Table 4. <Color b-value>
A color b-value of the cement composition was measured using a color meter
(Spectro Color Meter Se2000, manufactured by Nippon Denshoku Industries Co., Ltd.), and the results are shown in Table 4. <Amount of water required for normal consistency of cement paste>
An amount of water required for normal consistency of cement paste is a water amount required to obtain a constant softness of a cement paste, and, the larger the amount of water required for normal consistency of cement paste, the lower the fluidity of cement. A measurement method is as follows. 500 g of the cement composition is placed in a kneading vessel, and water is added thereto and the composition is kneaded and then, the resultant cement paste is placed in a container and the surface of the paste is rendered smooth. Then, a standard bar is allowed to go down on the cement paste, and, after 30 seconds, a gap between the end of the standard bar and the bottom plate is measured. A water amount such that the gap becomes 6+1 mm (normal consistency) is measured to determine an amount of water required for
I5 normal consistency of cement paste. <Setting (initial, final) and mortar compressive strength>
A setting time (initial, final) was measured using the above-obtained cement composition in accordance with JIS R5201: 1997 “Physical testing methods for cement”.
The results are shown in Table 4.
[0069] [Table 3]
Bogue equations
Exampled4 | 618 | 11.0 | 96 | 86
[0070] [Table 4] ~~] Fineness properties Color b- Amount of Setting time value (-) water Mortar
Blaine 45 um required for compressiv specific | residue normal a e strength surface (% by consistency oh al foal for 28-day area mass) of cement 5¢ re se oe age (cme) water {minutes) | (minutes) (N/mm?) (0) 3240 | 80 | 647 | 27.8 | 136 | 196 [ 611
Example2 | 3280 | 68 | 681 | 282 | 135 | 105 | 624 3120 3250 | 12 | 713 [| 278 | 142 [ 202 [ 600
Comparative | 3509 4.8 5.70 28.0 123 188 56.6 example 1 [00711 Fig. 1 shows the relationship between the V content of the cement composition and the compressive strength for 28-day age. As seen from Fig. 1, when the V content of the cement composition is 0.0063 to 0.012% by mass (Examples 1 to 4, symbol “@” in Fig. 1), certain strength exhibiting properties (the mortar compressive strength for 28-day age is 60 N/mm? or more) can be maintained and improved. On the other hand, when the V content of the cement composition is less than 0.0063% by mass (Comparative Example 1, symbol “LI” in Fig. 1), the strength exhibiting properties become poor. Further, as seen from Table 4, the cement compositions (Examples 1 to 4) having a V content of 0.0063 to 0.012% by mass and preferably having a Sr content of 0.035 to 0.08% by mass maintain and improve the certain strength exhibiting properties, and have an amount of water required for normal consistency of cement paste comparable to that of the cement composition (Comparative Example 1) having a V content of less than 0.0063% by mass, and have rather an increased setting time, which has confirmed that the fresh properties (the amount of water required for normal consistency of cement paste, setting time) are maintained.
[0072] As can be seen from the results shown above, when the cement composition has a V content of 0.0063 to 0.012% by mass and preferably has a Sr content of 0.035 to 0.08% by mass, the cement composition can maintain and improve the strength exhibiting properties of a mortar or concrete while maintaining the fresh properties (the amount of water required for normal consistency of cement paste, setting time) of the mortar or concrete.
Claims (8)
1. A cement composition having a V content of 0.0063 to 0.012% by mass.
2. The cement composition according to claim 1, which has a Sr content of
0.035 to 0.08% by mass.
3. The cement composition according to claim 1 or 2, which has a Mo content of
0.0002 to 0.007% by mass and a MgO content of 1 to 3% by mass.
4. The cement composition according to any one of claims 1 to 3, which is obtainable by using a cement clinker having a SO; content of 0.2 to 1.2% by mass.
5. The cement composition according to any one of claims 1 to 4, which has a SO; content of 1.6 to 2.5% by mass.
6. The cement composition according to any one of claims 1 to 5, which has an R,0 content of 0.3 to 0.6% by mass.
7. The cement composition according to any one of claims 1 to 6, which has a C58 content of 45 to 70% by mass, a C;S content of 5 to 25% by mass, a C3A content of 6 to 15% by mass, and a C4AF content of 7 to 15% by mass.
8. A method for producing a cement composition, the method comprising the steps of: (A) controlling the raw material unit consumption of a raw material for cement clinker selected from the group consisting of limestone, silica, coal ash, clay, blast furnace slag, soil generated by construction, sewage sludge, a hydrocake, and an iron source so that the resultant cement composition has a V content of 0.0063 to 0.012% by mass, and subjecting the raw material having the controlled unit consumption to calcination to produce a cement clinker; and (B) pulverizing the produced cement clinker, together with gypsum and an additive material.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2011051725A JP5029768B1 (en) | 2011-03-09 | 2011-03-09 | Cement composition and method for producing the same |
| PCT/JP2011/079223 WO2012120747A1 (en) | 2011-03-09 | 2011-12-16 | Cement compositions and process for producing same |
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| SG193341A1 true SG193341A1 (en) | 2013-10-30 |
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| JP (1) | JP5029768B1 (en) |
| KR (1) | KR101828120B1 (en) |
| CN (1) | CN103415483B (en) |
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| WO (1) | WO2012120747A1 (en) |
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| JP6061080B2 (en) * | 2012-12-28 | 2017-01-18 | 三菱マテリアル株式会社 | Hydraulic composition containing cerium and method for suppressing strength reduction thereof |
| JP6112900B2 (en) * | 2013-02-21 | 2017-04-12 | 株式会社トクヤマ | Method for producing raw material particles for producing cement clinker |
| JP5907440B1 (en) * | 2014-11-13 | 2016-04-26 | 住友大阪セメント株式会社 | Cement clinker and cement composition |
| JP5907439B1 (en) * | 2014-11-13 | 2016-04-26 | 住友大阪セメント株式会社 | Cement clinker and cement composition |
| CN104844091B (en) * | 2015-05-05 | 2017-07-28 | 中国建筑材料科学研究总院 | A kind of raw-soil suitable for raw-soil building block builds binding material and preparation method thereof by laying bricks or stones |
| JP6323484B2 (en) * | 2016-03-22 | 2018-05-16 | 住友大阪セメント株式会社 | Cement clinker composition and blast furnace cement composition |
| JP6500277B2 (en) * | 2016-03-22 | 2019-04-17 | 住友大阪セメント株式会社 | Cement clinker composition and portland cement composition |
| CN116573869B (en) * | 2023-05-26 | 2024-05-28 | 安徽建筑大学 | Method for producing cement clinker by using slag waste |
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| FR2864074B1 (en) * | 2003-12-18 | 2006-05-19 | Lafarge Sa | HYDRAULIC MINERAL COMPOSITION AND PROCESS FOR THE PRODUCTION THEREOF, CEMENTITIOUS PRODUCTS AND HYDRAULIC BINDERS CONTAINING SUCH A COMPOSITION |
| CN1785878A (en) * | 2004-12-12 | 2006-06-14 | 攀钢集团钢城企业总公司废旧物资分公司 | Method of using vanadium titanium rotary furnace steel slag as cement iron correction material |
| DE102007035257B3 (en) * | 2007-07-27 | 2008-11-13 | Forschungszentrum Karlsruhe Gmbh | Single-phase hydraulic binder, process for its preparation and building material produced with this binder |
| JP2011020890A (en) * | 2009-07-15 | 2011-02-03 | Ube Industries Ltd | Method for reducing hydration heat of cement composition and method for producing the cement composition |
| JP4811534B1 (en) * | 2010-06-01 | 2011-11-09 | 宇部興産株式会社 | CEMENT COMPOSITION AND METHOD FOR PRODUCING CEMENT COMPOSITION |
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| WO2012120747A1 (en) | 2012-09-13 |
| KR20140015442A (en) | 2014-02-06 |
| CN103415483A (en) | 2013-11-27 |
| KR101828120B1 (en) | 2018-02-09 |
| CN103415483B (en) | 2015-09-30 |
| JP2012188308A (en) | 2012-10-04 |
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