JP2818235B2 - Spherical cement and its production method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a spherical cement capable of producing a dense concrete with a low water cement ratio and a method for producing the same.

[Background Art] Conventionally, for example, to manufacture Portland cement as cement, a raw material is pulverized and baked in a rotary kiln, and then the obtained cement clinker is quenched with air. Then, gypsum powder is added to the cooled cement clinker, which is further pulverized by a tube mill or the like to obtain cement having a desired particle size.

"Problems to be Solved by the Invention" By the way, in the cement obtained in this manner, since the cement has a square shape due to pulverization, the frictional resistance between the particles is large and the cement and water are kneaded. ,
There is a problem that the fluidity and the filling property are slightly inferior.

[Means for Solving the Problems] In the spherical cement and the method for producing the same according to claims 1 and 2 of the present invention, cement clinker fine particles and an organic binder or an inorganic binder are dispersed in a solvent other than water, and then these dispersions are dispersed. The solution to the above problem was to granulate the cement clinker fine particles and the binder into a spherical shape and then add gypsum powder to the granulated cement clinker to obtain a spherical cement.

In the spherical cement and the method for producing the same according to claims 3 and 4, cement clinker fine particles, gypsum powder, and an organic binder or an inorganic binder are dispersed in a solvent other than water, and these dispersed cement clinker fine particles, gypsum powder and The method of solving the above problem is to granulate the binder into a sphere and obtain a spherical cement.

Hereinafter, the first and second aspects of the present invention will be described in detail.

First, the raw material is pulverized and fired in a rotary kiln in the same manner as in the prior art, and the resulting cement clinker is quenched with air. Then, the cooled cement clinker is finely pulverized again by a tube mill or the like, and is finely classified and classified to a mean particle size of about 10 μm or less. This is to make the average particle diameter of the obtained cement powder substantially the same as that of the conventional cement after granulation by adding a binder as described later.

Separately, a solvent is prepared in such an amount that the cement clinker fine particles can be dispersed sufficiently uniformly. As the solvent used here, solvents other than water are used, for example, ethanol, methanol, benzene, acetone, toluene, xylene, glycols, ether,
One or more mixtures selected from organic solvents such as petroleum solvents are preferred, but ethanol is most preferred from the viewpoint of safety. When ethanol is used, it is desirable to use ethanol having a purity of 99.5% or more and a small proportion of water. The reason that water cannot be used as a solvent is that water reacts with the cement clinker to cause a hydration reaction, and if a hydration reaction occurs at this stage, the function as cement is lost. is there.

Next, an organic binder or an inorganic binder is added to the solvent. As organic binders, polystyrene, ABS resin, methacrylic resin, vinyl acetate resin,
Cellulose resin, polycarbonate, silicone resin, natural rubber derivative, butadiene synthetic rubber, olefin synthetic rubber, chlorosulfonated polyethylene, phenol resin, urea resin, melamine resin, xylene resin, polyester resin, epoxy resin, polyurethane resin, polyimide At least one selected from polyethylene, polypropylene, polyvinyl chloride, AS resin, polyamide, polyacetal, polycarbonate, PET resin, PBT resin, polyphenylene ether, fluororesin, unsaturated polyester resin, polysulfide synthetic rubber, etc. is used. Can be The addition amount of these organic binders varies depending on the resin used, but is about 0.1 to 5 parts by weight based on 100 parts by weight of the cement clinker whose particle size has been adjusted. That is, if it is less than this range, it will be difficult to granulate as described later, and if it is more than this range, the properties of the resulting cement will be reduced.

As the inorganic binder, an alkoxylate-based one obtained by dispersing ethyl silicate, methyl silicate, or the like in ethyl alcohol or methyl alcohol and performing a dehydration reaction is preferably used. The addition amount of these inorganic binders is about 0.1 to 5 parts by weight based on 100 parts by weight of cement clinker for the same reason as in the case of the organic binder described above.

Next, the cement clinker having the adjusted particle size is added to a solvent to which a binder has been added to disperse the same. Needless to say, the amount of cement clinker added in this case satisfies the range of the mixing ratio with the binder amount described above.

Next, the solvent in which the cement clinker and the binder are dispersed is supplied to the granulating device, and the cement clinker and the binder are granulated in a spherical shape. As a granulation device,
A rotary tumbling granulator, a fluidized bed / spouted bed, a Henschel type / Pagmill type, an Erich-type stirring granulator, etc. are used.
The particle diameter of the cement clinker obtained by granulation is desirably adjusted so as to have an average particle diameter of 20 to 30 μm. This is because if it is less than 20 μm, a large amount of water is required and the strength is not obtained, and if it exceeds 30 μm, the fluidity and filling property of the cement obtained by adding gypsum powder to this are almost the same as conventional cement. This is because the advantage of granulating into a spherical shape is lost.

Thereafter, about 0.5 to 5 parts by weight of gypsum powder is added to 100 parts by weight of the granulated cement clinker, and the desired hydraulic speed is adjusted to obtain the spherical cement of the present invention. Naturally, as the gypsum powder, it is preferable to use one having a particle size corresponding to the particle size of cement clinker, and therefore, it is desirable to use one having an average particle size of about 20 to 30 μm. Further, the gypsum powder itself is more preferably spherical, and for example, it is desirable to use a gypsum powder that has been subjected to a spheroidizing treatment in a gypsum manufacturing process. The spherical cement obtained in this manner has a small frictional resistance between particles due to its spherical shape, and therefore has a large flow value at the same water cement ratio as compared with conventional cement.
Since the fluidity and the filling property are improved by this, the strength of the hardened cement after hardening is higher than that of the conventional cement. Further, the point that the inventions of claims 3 and 4 are different from the examples of the inventions of claims 1 and 2 is that instead of adding gypsum powder later, the gypsum powder is dispersed in a solvent together with a cement clinker and then granulated together with a binder. It is. Therefore, as the gypsum powder used in this case, fine
Adjusting the average particle size to about 10 μm or less, like the cement clinker whose particle size is adjusted to about m or less,
It is desirable to adjust the particle size of the spherical cement as a product obtained by granulation.

Even in the spherical cement thus obtained, since the cement clinker and the gypsum powder are granulated at the same time to form a sphere, the cement particles as a product become more uniform and maintain a sphere. The effect described in the example becomes more remarkable.

In the above example, the solvent and the binder were mixed in advance, and the cement clinker was added thereto to disperse this.However, the cement clinker was dispersed in the solvent first, and then the binder was added. Of course it is good.

"Examples" Hereinafter, the present invention will be described more specifically with reference to examples based on JIS standard mortar.

(Example 1) A cement clinker was produced by a conventional production method,
The obtained cement clinker is pulverized to an average particle size of 2 μm.
Was adjusted. Separately, 1% by weight of an epoxy resin was dispersed in methanol to prepare a binder solution.

Next, the cement clinker whose average particle size was adjusted was put into a Henschel granulator, and granulation was performed while the binder solution was dropped.

Observation of the obtained cement clinker with an electron microscope photograph revealed that the shape was substantially spherical and the average particle size was about 23 μm.

(Example 2) A cement clinker was produced by a conventional production method,
The obtained cement clinker is pulverized to an average particle size of 2 μm.
Was adjusted. Separately, 1% by weight of ethyl silicate was dispersed in ethanol and a dehydration reaction was carried out to prepare a binder solution.

Next, a cement clinker whose average particle diameter was adjusted was added to the binder solution at a weight ratio of 1: 1 and dispersed to obtain a slurry. Thereafter, the slurry was dried with a spray drier and granulated.

Observation of the obtained cement clinker with an electron micrograph showed that the shape was substantially spherical and the average particle size was about 25 μm.

A mortar was prepared by adding standard sand and water to the cement clinker thus obtained in the following formulation. The compression strength, bending strength and flow value of this mortar were examined based on JIS standard mortar, and the results are shown in Table 1.

Cement; 520 g Standard sand; 1040 g Water; 338 g (W / C = 65%) For comparison, a mortar was prepared by the above-mentioned composition using a conventional cement, and its compressive strength and bending strength were the same as in the above examples. , And the flow values are checked, and the results are shown in Table 1.

From the results shown in Table 1, it was confirmed that the example had better compressive strength, bending strength, and flow value than the comparative example.

"Effects of the Invention" As described above, the spherical cement and the method for producing the same according to the present invention comprise dispersing the cement clinker alone or together with the gypsum powder in a solvent other than water, further adding a binder, and granulating the spherical cement. Is what you get. Therefore, the spherical cement has a small frictional resistance between particles due to its spherical shape, and therefore has a large flow value at the same water cement ratio as compared with the conventional cement. Then, since the fluidity is improved and the filling property is improved, the hardened cement body after hardening becomes dense, and the strength is higher than that of the conventional cement.

Continuation of front page (58) Field surveyed (Int.Cl. ⁶ , DB name) C04B 7/36 C04B 7/02

Claims (4)

(57) [Claims] A cement clinker fine particle and an organic binder or an inorganic binder are dispersed in a solvent other than water, and then the dispersed cement clinker fine particles and the binder are granulated in a spherical shape. A spherical cement, characterized by being obtained by adding 2. Cement clinker fine particles and an organic binder or an inorganic binder are dispersed in a solvent other than water, and the dispersed cement clinker fine particles and the binder are granulated in a spherical form. A method for producing a spherical cement, characterized in that a cement is added. 3. Cement clinker fine particles, gypsum powder, an organic binder or an inorganic binder are dispersed in a solvent other than water, and the dispersed cement clinker fine particles, gypsum powder and binder are granulated in a spherical form. A spherical cement characterized by the above. 4. A method of dispersing cement clinker fine particles, gypsum powder, an organic binder or an inorganic binder in a solvent other than water, and then granulating the dispersed cement clinker fine particles, gypsum powder and binder into a spherical shape. Of producing spherical cement.