JP2011051810A - Quick hardening clinker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a quick hardening clinker of jet cement clinker type which secures a prescribed handling time at a low temperature and has an early-time strength actualizing property. <P>SOLUTION: The quick hardening clinker contains ≥50 mass% 3CaO-SiO<SB>2</SB>, 20 to 30 mass% 11CaO-7Al<SB>2</SB>O<SB>3</SB>-CaF<SB>2</SB>and 0.5 to 1.6 mass% Ti expressed in terms of TiO<SB>2</SB>, and preferably further contains 4 to 6 mass% 4CaO-Al<SB>2</SB>O<SB>3</SB>-Fe<SB>2</SB>O<SB>3</SB>. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a quick-hardening clinker, particularly used for quick-hardening cement, mortar and concrete used under low temperature conditions in the field of construction and civil engineering, and has good early strength development not only at normal temperature but also at low temperature. It relates to a rapid hardening clinker.

In construction work for tunnels and underground spaces, water stoppage work, road construction work, etc., it is desired to secure the pot life of mortar and concrete and harden them immediately.
In order to develop early strength, ultrafast cement is used for such mortar, concrete, and the like. For example, jet cement clinker and jet cement containing gypsum as main components, Irwin type containing C ₄ A ₃ SO ₃ as main components. There are clinker and ordinary Portland cement or early strength cement and gypsum as the main component, alumina cement clinker and CA as the main component, and ordinary Portland cement or early strength cement and gypsum as the main component.

Alumina cement clinker containing CA as a main component is inferior in hardness to a clinker containing 12CaO · 7Al ₂ O ₃ (hereinafter referred to as C ₁₂ A ₇ ) as a main component. It is also known that rapid hardening can be improved by melting raw materials at these CaO / Al ₂ O ₃ molar ratios and quenching them to form amorphous calcium aluminate clinker.
The calcium aluminate clinker is obtained by i) producing only by a solid phase reaction, ii) producing it by firing in a system in which a liquid phase and a solid phase are mixed, or iii) producing the whole amount by melting. For example, in the case of amorphous C ₁₂ A ₇ which is a rapid hardening component, it can be obtained by once melting a clinker raw material mainly composed of C ₁₂ A ₇ and then rapidly cooling it.
In order to control crystalline / amorphous, it is necessary to control the cooling rate, and when it is amorphous, the molten clinker that cools the molten clinker raw material from a higher temperature than that for producing the crystalline This can be achieved by putting the raw material into water and quenching it, or cooling it by blowing a large amount of air. For this reason, the manufacturing method is complicated, and in the manufacturing method, since the electrofusion method is used for melting the clinker, there is a problem that a large amount of power is consumed, the power cost is increased, and the manufacturing cost is increased. is there.

Irwin clinker contains urwin (C ₄ A ₃ SO ₃ ) having a rapid hardening property because it usually contains 70% by mass or more, and is used as a clinker for rapid hardening cement. It is difficult to produce a clinker, and due to the characteristics of the rapid-hardening component, there is a problem that it is inferior in rapid hardening compared to other rapid-hardening clinker, and particularly inferior in rapid hardening at low temperatures. For this reason, in order to acquire rapid hardening at low temperature, it is necessary to increase the blending ratio of Irwin clinker or to add an accelerator to the super-hard cement composition.

  In addition, ultra-fast hard cements using alumina cement clinker and Irwin clinker require separate adjustment and mixing of calcium silicate components as a source of calcium ions. Etc. are used. Further, since these components need to be added, extra labor and cost are produced in comparison with jet cement when the above-mentioned super-hard cement (using an alumina cement clinker and an Irwin clinker) is manufactured.

On the other hand, the jet cement clinker has a 3CaO.SiO ₂ (hereinafter referred to as C ₃ S) calcium silicate phase as a main component, and 11CaO · 7Al ₂ O ₃ · CaF ₂ (hereinafter referred to as C ₁₁ A ₇ · CaF) as a fast-hardening component. ₂ hereinafter) is a clinker containing 30 wt% to 20 wt%, and clinker the cost increase factor of production described above is not, with excellent early strength development of further at lower temperatures than conventional jet cement clinker It is desired.

JP 2007-51014 A (Patent Document 1) discloses that a clinker composition containing erwin contains 1 wt% titanium oxide in order to provide an erwin-containing composition that can stably generate erwin and has no quality variation. Hereinafter, a calcium sulfoaluminate clinker composition containing 1 to ₃ wt% of magnesium oxide and having an Erwin content of 90% or more in the total amount of Irwin and C ₃ A has been proposed.
In the calcium sulfoaluminate-based clinker composition, by controlling the content of titanium oxide and magnesium oxide, a clinker composition having a higher amount of Irwin than C ₃ A at a firing temperature of 1350 ° C. or less was obtained. Yes.

JP 2007-514634 (Patent Document 2) also describes a vitreous or crystallization matrix based on silico-calcium aluminate and magnesium that occupies at least 25%, preferably at least 30% of the amount of the composition. ; Ti, V, Cr, Mn, Co, Ni, Cu, Pb, Ba, Sr, P, S, Na, K, Zr, Mo, Be, Tl, As, Sn, occupying at least 5% of the compositional amount And one or several specific inorganic oxides selected from oxides and halides of Cd and one or several specific inorganic halides as optional components; at most 31% by weight of alumina (Al ₂ O ₃ ); less than 10% by weight of ferrite (calcium aluminoferrite); and less than 0.05% by weight with respect to the amount of the composition material, preferably A hydraulic inorganic composition characterized by containing less than 0.01% by mass of C is disclosed.

Japanese Patent No. 3179702 (Patent Document 3) discloses a clinker composition used for rapid hardening cement, quick setting material, quick setting cement, ground improvement material, masking material, etc. A clinker material mainly composed of ₁₂ A _7- based calcium aluminate contains 0.1 to 9% by mass of Fe ₂ O ₃ and 0.1 to 9% by mass of CaF ₂ at low temperature. The melt generation start temperature of the low-temperature melt phase and the high-temperature melt phase is lowered by generating a melt phase and a high-temperature melt phase and adding 0.5 to 9% by mass of TiO _2. A rapid-hardening clinker composition characterized by being fired is disclosed.

However, these conventional quick-hardening clinker is difficult to develop early strength at low temperature with the addition ratio of fast-hardening components equivalent to jet cement, and a certain pot life (handling time) at low temperature However, it takes time to develop strength in emergency construction during construction and civil engineering work, and therefore, it has not been sufficiently hard.
Therefore, in consideration of application at a low temperature, more rapid hardening and high early strength development are desired.

JP 2007-51014 A JP 2007-514634 A Japanese Patent No. 3179702

  An object of the present invention is to provide a quick-hardening clinker for jet cement that can ensure a predetermined handling time not only at normal temperature but also at low temperature and has early strength development.

The present invention has been achieved by finding that early strength development at low temperatures can be obtained by containing TiO ₂ at a constant content in a jet cement clinker.
That is, the rapid-hardening clinker of the present invention has 50% by mass or more of C ₃ S as a main component, 20 to 30% by mass of C ₁₁ A ₇ · CaF ₂ , and 0.5 to 1.6 in terms of Ti in terms of TiO _2. It is characterized by containing mass%.
Preferably, the quick-hardening clinker of the present invention is a quick-hardening clinker in which the content of TiO ₂ is 1.0 to 1.6% by mass in the quick-setting clinker.
Furthermore, the rapid-hardening clinker of the present invention is a rapid-hardening clinker that further contains 4 to 6% by mass of 4CaO.Al ₂ O ₃ .Fe ₂ O ₃ (hereinafter referred to as C ₄ AF).

The rapid-hardening clinker of the present invention is excellent not only at room temperature but also at a low temperature, for example, 5 ° C., while maintaining a certain handling time and is excellent in early strength development. Therefore, it is used under low temperature conditions in the construction and civil engineering fields. This is a jet cement clinker that can be effectively used for quick-hardening cement, mortar, grout and concrete, and the use time can be shortened by using the clinker.
The rapid-hardening clinker of the present invention is excellent not only in low temperature but also in early strength development at normal temperature.
Furthermore, the rapid-hardening clinker of the present invention can use a material containing Ti as a clinker raw material, for example, a waste containing TiO ₂ as a raw material.

FIG. 1 is a diagram showing the relationship between mortars using different rapid-hardening clinker and compressive strength at 5 ° C. for 3 hours.

The present invention is illustrated by the following preferred examples, but is not limited thereto.
Rapid hardening clinker of the present invention, as the mineral phase, _{C 3} S 50 mass% or _more, the C ₁₁ A 7 · CaF ₂ 20~30 wt%, a Ti oxide in terms of TiO ₂ 0.5 to 1.6 It is contained by mass%.

That is, if the jet clinker containing C ₃ S as a main component and containing C ₁₁ A ₇ · CaF ₂ in the above amount contains 0.5 to 1.6% by mass of TiO ₂ , Furthermore, early strength development can be made excellent even at low temperatures, and a certain handling time can be secured.

The rapid-hardening clinker of the present invention contains 50 mass% or more of C ₃ S, which is a calcium silicate phase, preferably 60 mass% or more, more preferably 65 mass% or more, and C is a fast-hardening component. ₁₁ A ₇ · CaF ₂ is contained in an amount of 20 to 30% by mass, preferably 24 to 28% by mass.
When the C ₃ S is outside the above range, the supply of Ca ions becomes insufficient when the hydration reaction of the C ₁₁ A ₇ · CaF ₂ phase, which is the calcium aluminate phase in jet cement, proceeds, and the early stage Inhibits strength expression.
Moreover, fast when C _{11 A} 7 _· CaF ₂ is rigid component is outside the above range, can not be obtained sufficiently steep rigid, with would be inferior suddenly rigid, particularly in cold, C ₁₁ A ₇ in the course of manufacturing · CaF ₂ becomes too melted, poor rapid hardening, without the effects of the present invention can be obtained.
Moreover, if the components melted in the cement kiln increase too much, the operation cannot be performed.

The rapid-hardening clinker of the present invention further contains Ti in an amount of 0.5 to 1.6% by mass, preferably 1.0 to 1.6% by mass in terms of TiO ₂ oxide.
By containing TiO ₂ in the above range, the rapid hardness at a low temperature, for example, the initial strength development at 5 ° C. or less (3 hours after construction, etc.) will be excellent.
Furthermore, since TiO ₂ is present, the melt generation temperature during clinker generation can be lowered and the melt generation temperature range can be expanded at the same time, so the clinker is fired by a general rotary kiln or other sintering method. Furthermore, since the melt production temperature is lowered, the clinker can be fired at a lower temperature.
In addition, the solid solution amount of TiO _{2 in} the clinker crystal of the present invention is increased, the rapid hardening property of the clinker at low temperature is improved, and the initial strength development is also excellent.

More preferably, the rapid-hardening clinker of the present invention contains 3 to 10% by mass, preferably 4 to 6% by mass of C ₄ AF.
The inclusion of such a C ₄ AF (4CaO.Al ₂ O ₃ .Fe ₂ O ₃ ) mineral phase is preferable because the mineral formation reaction through the liquid phase and the solid phase is promoted during firing. Further, if the content ratio is less than 3% by weight, the mineral formation reaction is not promoted, and it takes a long time for firing, which is not preferable. If it exceeds 10% by weight, the liquid phase component (melt having C ₁₁ A ₇ · CaF ₂ and C ₄ AF as main components) becomes excessive at the time of firing, and firing with a cement kiln becomes difficult.

The clinker of the present invention may contain, for example, C ₂ S or C ₂ AS in addition to the mineral phase.

The quick-hardening clinker of the present invention is a clay raw material classified into silicate minerals such as calcareous raw materials such as quick lime, slaked lime and limestone as a calcium source, feldspar and zeolite as a silica source based on the Borg formula, Alumina, alumina, alumina raw materials such as bauxite and band shale, band shale as TiO ₂ source, rutile or anatase or ilmenite ore (titanite), and calcium fluoride raw material as required The product is fired using a heating furnace such as an electric furnace and cooled to obtain a jet cement clinker containing TiO ₂ .
Further, fluorite can be exemplified as the calcium fluoride raw material.

  The rapid hardening clinker of this invention can be obtained by baking the said mixing | blending raw material sufficiently, for example at the temperature of 1250-1400 degreeC, for example for 0.5 to 3 hours.

The quick-hardening clinker of the present invention can be pulverized into a quick-hardening clinker powder, and sulfate can be added to the quick-hardening clinker powder and used as a quick-hardening cement composition.
The rapid hardening clinker of the present invention is preferably used by pulverizing to a brain specific surface area of 4500 cm ² / g or more, and if it is less than 4500 cm ² / g, good rapid hardening may not be obtained.
Further, if the specific surface area of the brain is too large, pulverization time is required, the productivity is lowered and the cost is increased, so 5000 to 7000 cm ² / g is desirable.
Further, a grinding aid (diethylene glycol, triethanolamine, etc.) may be added when grinding.

Examples of sulfates include alkali metal sulfates such as sodium sulfate (sodium sulfate) and potassium sulfate, alkaline earth metal sulfates such as magnesium sulfate and gypsum (calcium sulfate), and aluminum sulfate. It is preferable to use gypsum or a combination of gypsum and mirabilite.
Examples of the gypsum include anhydrous gypsum, hemihydrate gypsum, dihydrate gypsum, or a mixture thereof.
Moreover, slaked lime is mentioned as a material which can be mix | blended as needed. The slaked lime is added for further strength enhancement.

The fineness of these sulfates and slaked lime is not particularly limited, but is preferably 3000 cm ² / g or more. In view of strength development and cost, a fineness of 4000 to 10000 cm ² / g is more preferable.
From the point of securing rapid hardening and handling time, 65 to 90% by mass of the rapid hardening clinker of the present invention, 5 to 35% by mass of sulfate, and 0 to 5% by mass of slaked lime are blended to obtain a rapid hardening cement. It is desirable.

In the above ratio, if the rapid hardening clinker powder of the present invention is less than 65% by mass, the rapid hardening becomes small, and if it exceeds 90% by mass, the instantaneous setting is impossible and the handling time cannot be secured.
In addition, when the sulfate is less than 5% by mass, it is impossible to secure a handling time due to instantaneous setting, and when it exceeds 35% by mass, the rapid hardening is reduced, and the presence of excess sulfate ions causes delayed expansion, Since there is a risk of causing expansion and destruction, neither is preferable.

  The method for mixing the rapid-hardening clinker powder, sulfate, and slaked lime of the present invention is not particularly limited.

  In addition, setting retarders (lignin sulfonic acid, oxycarboxylic acid, various organic acids such as saccharides, alkali metal salts or alkaline earth metal salts of organic acids) and water reducing agents (alkyl allyl sulfonic acid, naphthalene sulfonic acid) , Melamine sulfonic acid, polycarboxylic acid, AE water reducing agent, high performance water reducing agent, high performance AE water reducing agent etc.) and other liquid or powder admixtures and fine aggregates (river sand, sea sand, mountains) Sand, crushed sand and mixtures thereof), coarse aggregate (river gravel, sea gravel, crushed stone and mixtures thereof) and the like can be blended.

  Mortar and concrete can be produced by blending water into the cement composition using the above raw material containing the rapid-hardening clinker of the present invention. The manufacturing method of these mortar and concrete is not specifically limited, What is necessary is just to mix a raw material with a conventional mixer.

The invention is illustrated by the following examples and comparative examples.
(Examples 1-3, Comparative Examples 1-3)
Prepared by blending reagents so as to have the chemical composition shown in Table 1 below, each blended clinker raw material mixture was baked at a temperature of 1350 ° C. for 1 hour using an electric furnace, and then removed from the electric furnace. Then, each clinker was obtained by quenching in air.

The chemical composition of each clinker thus obtained was analyzed using a fluorescent X-ray apparatus (Axios manufactured by Spectris Co., Ltd.), and the results are shown in Table 2 and in the Borg formula based on the chemical composition in Table 2. Table 3 shows the theoretical mineral composition obtained.
However, the theoretical mineral composition using the usual Borg formula can calculate C ₄ AF until Fe ₂ O ₃ is consumed, and then C ₃ A is generated until Al ₂ O ₃ is consumed. Then, the amount of C ₃ S and C ₂ S is calculated based on the contents of CaO and SiO _{2. In} Table 3, C ₁₁ A ₇ · CaF ₂ represents fluorine during the calculation. Calculate the amount of production in preference to C ₃ A until it is consumed, and if fluorine remains, it is assumed that fluorine will be consumed until Al ₂ O ₃ is consumed, and if fluorine remains, it is calculated that CaF ₂ exists. Except for this, it was obtained in the same manner as the calculation by the ordinary Borg equation as described above. In the example of the present invention and the comparative example, all the aluminum is consumed and becomes C ₁₁ A ₇ · CaF ₂ .

Next, each clinker was coarsely pulverized, and for Examples 1 to 3 and Comparative Example 1, the coarsely pulverized clinker and mirabilite (sodium sulfate) were blended in the blending ratio shown in Table 4, and further pulverized to obtain a Brain ratio. The surface area was pulverized to about 5200 ± 200 cm ² / g.
To the clinker and mirabilite powder, anhydrous gypsum (trade name: non-clave, manufactured by Sumitomo Osaka Cement Co., Ltd.), hemihydrate gypsum (trade name: baked gypsum, manufactured by Wako Pure Chemical Industries, Ltd.) and slaked lime (Wako Pure Chemical Industries, Ltd.) Kogyo Co., Ltd.) was blended at a blending ratio shown in Table 4 and mixed uniformly to prepare each cement composition.
For Comparative Examples 2 and 3, after crushing the coarsely pulverized clinker (the brain specific surface area is about 4000 ± 200 cm ² / g), the anhydrous gypsum and early strong cement (HC; manufactured by Sumitomo Osaka Cement Co., Ltd.) are shown in Table 4. The mixture was uniformly mixed at the blending ratio shown in the following to prepare a cement composition.
For Comparative Examples 4 and 5, the pulverized clinker and mirabilite were mixed at the mixing ratio shown in Table 4, and further pulverized to a Blaine specific surface area of about 5200 ± 200 cm ² / g. Anhydrous gypsum, the hemihydrate gypsum, and the slaked lime were blended at a blending ratio shown in Table 4 and mixed uniformly to prepare a cement composition.
Each mortar was prepared by mix | blending water (tap water) with each compound composition obtained by the compounding ratio shown in Table 4, and knead | mixing uniformly.

For each mortar, the compressive strength after 3 hours of age at a temperature of 5 ° C. was measured according to JIS R 5201, and the results are shown in Table 5 and FIG.
In addition, Table 5 shows the measurement results of the handling time at a temperature of 5 ° C. for each mortar.
However, the handling time was measured as follows.
Measurement of handling time: Measurement is performed using a handling time measuring cone having a diameter of 1 inch and a height of 2 inches and a JIS mortar setting tester (Vicat needle device). A handling time measuring cone is attached to the Vicat needle device, and the weight of the descending object is adjusted to 350 g. Pack the mortar into the JIS mortar setting test form as in the flow test to smooth the surface. Set the tip of the cone attached to the Vicat needle device in contact with the mortar surface, drop the cone onto the mortar and read the penetration depth of the cone. The time from the time of water injection when the penetration depth reaches 1.5 mm is defined as the handling time.

From FIG. 1, the mortars of Examples 1 to 3 using clinker containing TiO ₂ in an amount of 0.5% by mass or more, particularly 1% by mass or more have a compressive strength after 3 days of 15 N / mm ² or more. It can be seen that early strength development is excellent and has a handling time of 28 minutes or more.

  The quick-hardening clinker of the present invention is used for mortar, cement and concrete, construction work for tunnels and underground spaces, book poisoning work, water stop work, spraying work on wall surfaces, repair work for urgent roads, etc. Can be effectively applied when early strength development is desired under low temperature conditions such as in winter.

Claims (3)

3CaO · SiO ₂ is contained in an amount of 50% by mass or more, 11CaO · 7Al ₂ O ₃ · CaF ₂ is contained in an amount of 20 to 30% by mass, and Ti is contained in an amount of 0.5 to 1.6% by mass in terms of TiO _2. Hard clinker. The quick-hardening clinker according to claim 1, wherein the content of TiO ₂ is 1.0 to 1.6% by mass. The rapid-hardening clinker according to claim 1 or 2, further comprising 4 to 6% by mass of 4CaO.Al ₂ O ₃ · Fe ₂ O ₃ .

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