JP2007176745A - Grinding method for molten or fired clinker containing hydration reactive substance - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a grinding method which is suitable for grinding molten or fired clinker containing a hydration reactive substance, obtains excellent grinding effect comparable to the use of a grinding aid even if the grinding aid having an adverse effect by adhering to and remaining in a hydration reactive ground substance is not used, and can develop sufficient hydration reactivity without deteriorating. <P>SOLUTION: The grinding method for molten or fired clinker containing the hydration reactive substance comprises using iron and alumina in combination as grinding media, and grinding the clinker by using a ball mill. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for pulverizing a melted or fired clinker containing a hydration active substance such as cement.

Materials with relatively high hydration reaction activity, such as cement, quicklime, and calcium aluminate, which are widely used as building and civil engineering materials, are clinker obtained by heating and melting a given raw material or clinker obtained by firing. It is manufactured by crushing. The clinker is pulverized mainly by a ball mill using iron balls as a pulverizing medium from the viewpoint of productivity and impurities mixed during pulverization. Moreover, in order to obtain a moderate reaction activity, in order to quickly bring the fineness of the pulverized product to a desired value on a productive scale, the pulverized product is pulverized using a pulverization aid that increases the pulverization efficiency. Generally, as a grinding aid for ceramic materials, for example, oligomers of lower alkylene glycol such as propylene glycol and diethylene glycol, alkanolamines such as triethanolamine, fatty acids such as stearic acid or aromatic compounds such as phenol, hydroxyalkylhydrazine and the like Tertiary butyl acetic acid and the like are known. Of these, lower alkylene glycols and alkanolamines are particularly preferably used when the pulverized product is a hydration reaction active substance such as cement. (For example, see Patent Documents 1 and 2.)
JP-A-7-33487 JP 2002-160959 A

  When an organic grinding aid such as lower alkylene glycol or alkanolamines is used in combination to improve grinding efficiency by ball mill grinding, the grinding efficiency is increased, but the same is applied to the material to be ground having a relatively high hydration reaction activity. When the degree of fineness is adjusted, the influence of the pulverization aid remaining on the pulverized particles is more pronounced than when the pulverization aid is not used, and the reaction activity is lowered. This effect is especially noticeable for calcium aluminate as a fast-hardening / quick-setting component and quick lime as an expanding component, and this effect is significant and is used as an admixture component in cementitious compositions such as mortar and concrete. Then, it was easy to occur that setting was delayed and desired quick-hardness and quick setting were not obtained, or high expansibility was not fully obtained. Therefore, the present invention can obtain a high pulverization effect comparable to the case of using a pulverization aid without using such a pulverization aid that tends to cause residual effects, and without reducing the hydration reaction activity. It is an object of the present invention to provide a pulverization method suitable for pulverization of a melted or fired clinker containing a hydration active substance that can be sufficiently expressed.

  As a result of intensive investigations for solving the above problems, the present inventors have obtained a high pulverization effect without using a pulverization aid when performing ball mill pulverization using a specific pulverization medium. Even when the melted or fired clinker containing the substance was pulverized, the obtained powder did not decrease the reaction activity, and thus the present invention was completed.

  That is, this invention is a grinding | pulverization method of the melt | dissolution or baking clinker containing the hydration reaction active material represented by following (1)-(3). (1) A method for pulverizing a melted or fired clinker containing a hydration reaction active substance, wherein iron and alumina are used in combination in a pulverizing medium and pulverized by a ball mill. (2) The method for pulverizing molten or calcined clinker containing the hydration reaction active substance according to (1) above, wherein the average particle size of alumina used for the pulverization medium is 5 to 50% of the average particle size of iron . (3) The hydration reaction active substance according to (1) or (2) above, wherein the ratio of iron and alumina used for the grinding medium is 0.1 to 10 parts by volume of alumina with respect to 100 parts by volume of iron. A method for pulverizing molten or fired clinker containing

  According to the present invention, the grinding aid can be used even in the case of a pulverized product having a relatively high hardness without using an expensive grinding aid that is unnecessary after use in ball milling with high productivity. The pulverization efficiency can be increased to the extent that it is not inferior to that of the case, and high-powder powder can be easily obtained without reducing the original reaction activity. This is a particularly suitable method for grinding molten or calcined clinker.

  If the object to be pulverized by the method for pulverizing a melted or fired clinker containing the hydration reaction active substance of the present invention is an inorganic melted or fired clinker containing some hydration reaction active substance, Any material may be used as long as the hardness of the whole product is substantially equal to or less than that of the alumina polycrystal. Specific examples of the molten mass include calcium aluminate, calcium sulfoaluminate, and alumina cement or glass containing such a component as an active ingredient. Moreover, as calcinated clinker, normal, early strength, super early strength, low heat, moderate heat, etc. Portland cement, high belite cement, eco cement, jet cement and other cement clinker, limestone clinker as a main raw material, Examples thereof include magnesia clinker using magnesite or seawater-extracted magnesium hydroxide as a main raw material, dolomite clinker using dolomite as a main raw material, and clinker containing crystalline or / and amorphous calcium aluminate as an active ingredient. .

  In the method for pulverizing a melted or calcined clinker containing a hydration reaction active substance of the present invention, since it is excellent in productivity and a pulverized product having a relatively wide particle size range can be easily obtained, a dry method using a ball mill is used. Grind. The grinding media (balls) used for ball milling are made of iron and alumina. Since iron has high specific gravity, it can be expected to be pulverized by high impact force. Alumina is extremely high in hardness and excellent in wear resistance. The crushed object can be peeled off at any time, and the pulverization buffering action due to the crushed object can be remarkably suppressed. Thus, high grinding efficiency can be obtained without using a grinding aid generally used in the present invention.

  In the method for pulverizing molten or calcined clinker containing the hydration reaction active substance of the present invention, the particle size of iron and alumina used for the pulverization medium is such that the average particle size of alumina is the average particle size of iron in order to improve the pulverization efficiency. It is preferably 5 to 50% of the diameter. If the average particle diameter of alumina is less than 5% or more than 50% of the average particle diameter of iron, any of them is not suitable because the effect of preventing the object to be ground from adhering to the iron medium may be reduced. Further, although the particle size of iron varies somewhat depending on the internal volume of the ball mill and the particle size of the pulverized product to be obtained, it is preferably approximately 5 mm to 200 mm, and iron with a plurality of particle sizes in this range is used in combination. More preferably. Alumina having a plurality of particle sizes can also be used in combination. The inner wall material of the ball mill may be iron or alumina, but iron is recommended because it is less damaged.

  Further, in the method for pulverizing a melt or calcined clinker containing the hydration active substance of the present invention, the amount of iron and alumina used for the pulverization medium is 0.1 to 10 parts by volume of alumina with respect to 100 parts by volume of iron. preferable. If the amount of alumina is less than 0.1 part by volume, the effect of preventing the object to be ground to adhere to the iron medium may be significantly reduced. It is not appropriate because it may cause a decrease in power.

  Further, in the method for pulverizing a melted or calcined clinker containing a hydration reaction active substance of the present invention, the amount of the material to be pulverized and the pulverizing medium to be put into a ball mill at the time of pulverization is a bulk volume and a mill content volume. It is preferable to use a grinding medium in an amount corresponding to 10 to 50% of the above, and a grinding medium and an object to be ground in an amount corresponding to 25 to 75% of the volume of the mill by volume. If the amount is out of the range, the pulverization efficiency is lowered and it may be difficult to obtain a pulverized product having a desired fineness. More preferably, it is a pulverization medium in an amount corresponding to 20 to 45% of the mill content volume in bulk volume, and an pulverization medium and an object to be pulverized in an amount corresponding to 30 to 70% of the mill content volume in bulk volume. preferable. The pulverization time may be appropriately determined according to the type and amount of the pulverized material, the fineness of the pulverized material to be obtained, the used pulverization medium, and the like. For example, when a calcium aluminate having a particle size of 100 microns or less is to be obtained by crushing about 1 kg of a plurality of molten masses of about several to 10 cm, it can be crushed within 1 hour.

  EXAMPLES Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to the examples shown here.

[Example 1] Using 1 kg of alumina cement clinker obtained by heating and melting, a ball mill made of inner wall steel having an internal volume of 6 liters and having four types of particle diameters (diameters 10 mm, 15 mm, 18 mm, and 25 mm). Number of revolutions at 20 ± 1 ° C. using 2.5 kg of steel balls (total mass 10 kg, total volume 1.27 liters) and high purity alumina balls 40 g (volume 0.01 liters) with a particle size of 4 mm. Dry grinding was performed at 60 rpm for 40 minutes. As a result of measuring the specific surface area of the pulverized alumina cement clinker powder, it was 4490 cm ² / g. Next, as an evaluation of the hydration characteristics of the pulverized product, 400 g of the pulverized alumina cement clinker powder, 600 g of early strength Portland cement (manufactured by Taiheiyo Cement Co., Ltd.) and 400 g of water are blended and kneaded with a hand mixer for 1 minute. A paste was prepared. The cement paste immediately after the preparation was filled in a cement paste container for setting specified in JIS R 5201 and left in a room at 20 ± 1 ° C. Check the cured state of the filling every 2 minutes immediately after filling with the finger, press the surface with the finger for 10 seconds, and when there is no dent, deformation or crack, and there is no adhesion of the filling to the finger The elapsed time from immediately after filling was investigated. The result was 4 minutes.

[Example 2] 1 Kg of a crystalline calcium aluminate (12CaO.7Al ₂ O ₃ ) clinker obtained by firing was dry pulverized under the same conditions using the same ball mill and pulverizing medium as in Example 1. As a result of measuring the specific surface area of the pulverized crystalline calcium aluminate clinker powder, it was 4620 cm ² / g. Next, as an evaluation of the hydration characteristics of the pulverized product, 400 g of the pulverized crystalline calcium aluminate clinker powder, 600 g of ordinary Portland cement (manufactured by Taiheiyo Cement Co., Ltd.) and 400 g of water are blended and kneaded for 1 minute with a hand mixer. A cement paste was prepared. The cement paste immediately after the preparation was filled in a cement paste container for setting specified in JIS R 5201 and left in a room at 20 ± 1 ° C. Check the cured state of the filling every 2 minutes immediately after filling with the finger, press the surface with the finger for 10 seconds, and when there is no dent, deformation or crack, and there is no adhesion of the filling to the finger The elapsed time from immediately after filling was investigated. The result was 2 minutes.

[Comparative Example 1] Using 1 kg alumina cement clinker similar to Example 1 obtained by heating and melting, using an inner wall steel ball mill with an internal volume of 6 liters, four types of particle sizes (diameter 10 mm, 15 mm) were used. , 18 mm, 25 mm) using a steel ball of 2.5 kg each (total mass 10 kg, total volume 1.27 liters), was subjected to dry pulverization for 40 minutes at a rotation speed of 60 rpm at a temperature of 20 ± 1 ° C. The specific surface area of the pulverized alumina cement clinker powder was measured and found to be 2370 cm ² / g. Next, as an evaluation of the hydration characteristics of the pulverized product, 400 g of the pulverized alumina cement clinker powder, 600 g of early strength Portland cement (manufactured by Taiheiyo Cement Co., Ltd.) and 400 g of water are blended and kneaded for 1 minute with a hand mixer. A paste was prepared. The cement paste immediately after the preparation was filled in a cement paste container for setting specified in JIS R 5201 and left in a room at 20 ± 1 ° C. Check the cured state of the filling every 2 minutes immediately after filling with the finger, press the surface with the finger for 10 seconds, and when there is no dent, deformation or crack, and there is no adhesion of the filling to the finger The elapsed time from immediately after filling was investigated. The result was 20 minutes.

Comparative Example 2 Using 1 kg alumina cement clinker similar to Example 1 obtained by heating and melting, using an inner wall steel ball mill having an internal volume of 6 liters, four types of particle sizes (diameters 10 mm, 15 mm) were used. , 18 mm, 25 mm) steel balls of 2.5 kg each (total mass 10 kg, total volume 1.27 liters) and 1.0 g diethylene glycol as a grinding aid, at a temperature of 20 ± 1 ° C. and a rotation speed of 60 rpm For 40 minutes. As a result of measuring the specific surface area of the pulverized alumina cement clinker powder, it was 3300 cm ² / g. Next, as an evaluation of the hydration characteristics of the pulverized product, 400 g of the pulverized alumina cement clinker powder, 600 g of early strength Portland cement (manufactured by Taiheiyo Cement Co., Ltd.) and 400 g of water are blended and kneaded for 1 minute with a hand mixer. A paste was prepared. The cement paste immediately after the preparation was filled in a cement paste container for setting specified in JIS R 5201 and left in a room at 20 ± 1 ° C. Check the cured state of the filling every 2 minutes immediately after filling with the finger, press the surface with the finger for 10 seconds, and when there is no dent, deformation or crack, and there is no adhesion of the filling to the finger The elapsed time from immediately after filling was investigated. The result was 14 minutes.

[Comparative Example 3] A crystalline calcium aluminate (12CaO · 7Al ₂ O ₃ ) clinker 1Kg similar to Example 2 obtained by firing was used as a grinding medium using a ball mill made of inner wall steel having an inner volume of 6 liters. Using 2.5 kg of steel balls of 4 types of particle sizes (diameters 10 mm, 15 mm, 18 mm, and 25 mm) (total mass 10 Kg, total volume 1.27 liters) at a temperature of 20 ± 1 ° C. and rotating at 60 rpm For 40 minutes. The specific surface area of the pulverized crystalline calcium aluminate clinker powder was measured and found to be 2200 cm ² / g. Next, as an evaluation of the hydration characteristics of the pulverized product, 400 g of the pulverized crystalline calcium aluminate clinker powder, 600 g of ordinary Portland cement (manufactured by Taiheiyo Cement Co., Ltd.) and 400 g of water are blended and kneaded for 1 minute with a hand mixer. A cement paste was prepared. The cement paste immediately after the preparation was filled in a cement paste container for setting specified in JIS R 5201 and left in a room at 20 ± 1 ° C. Check the cured state of the filling every 2 minutes immediately after filling with the finger, press the surface with the finger for 10 seconds, and when there is no dent, deformation or crack, and there is no adhesion of the filling to the finger The elapsed time from immediately after filling was investigated. The result was 14 minutes.

[Comparative Example 4] A crystalline calcium aluminate (12CaO · 7Al ₂ O ₃ ) clinker 1Kg similar to Example 2 obtained by firing was used as a grinding medium using a ball mill made of inner wall steel having an inner volume of 6 liters. 20 ± 1 using 2.5 kg of steel balls of 4 types of particle diameters (diameters 10 mm, 15 mm, 18 mm, 25 mm) (total mass 10 Kg, total volume 1.27 liters) and 1.0 g of diethylene glycol as a grinding aid. Dry pulverization was performed for 40 minutes at a rotation speed of 60 rpm at a temperature of ° C. As a result of measuring the specific surface area of the pulverized crystalline calcium aluminate clinker powder, it was 3170 cm ² / g. Next, as an evaluation of the hydration characteristics of the pulverized product, 400 g of pulverized crystalline calcium aluminate clinker powder, 600 g of early strength Portland cement (manufactured by Taiheiyo Cement Co., Ltd.) and 400 g of water are blended and kneaded for 1 minute with a hand mixer. A cement paste was prepared. The cement paste immediately after the preparation was filled in a cement paste container for setting specified in JIS R 5201 and left in a room at 20 ± 1 ° C. Check the cured state of the filling every 2 minutes immediately after filling with the finger, press the surface with the finger for 10 seconds, and when there is no dent, deformation or crack, and there is no adhesion of the filling to the finger The elapsed time from immediately after filling was investigated. The result was 16 minutes.

Claims (3)

A method for pulverizing a melted or fired clinker containing a hydration reaction active substance, wherein iron and alumina are used in combination in a pulverizing medium and pulverized by a ball mill. The method for pulverizing a melted or fired clinker containing a hydration active substance according to claim 1, wherein the average particle size of alumina used for the pulverization medium is 5 to 50% of the average particle size of iron. The ratio of iron and alumina used for the grinding medium is 0.1 to 10 parts by volume of alumina with respect to 100 parts by volume of iron, or melting or baking containing a hydration reaction active substance according to claim 1 or 2 Clinker grinding method.