JPS6236051A - Granular cement and manufacture - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention Object of the Invention The present invention relates to a granular cement and a method for producing the same. It is an object of the present invention to provide cement and a preferred method for producing the same.

Industrial applications Portland cement Cement and its manufacturing technology Conventional technology Cement is indispensably used in civil engineering, construction, etc., but this cement can be used as a fine powder of, for example, 30 μm or smaller. manufactured and used.

That is, in order to obtain a mixed substance that is evenly and appropriately mixed with sand and other substances, it is essential to prepare it by pulverizing it into a fine powder.

Problems to be Solved by the Invention However, as mentioned above, pulverized cement tends to generate dust during work, and when it hits cross-wires, it is not always evenly distributed, creating so-called lumps, which must be crushed. special operations are required to achieve even crosstalk. Also, because of its fine powder form, it has poor fluidity and deaeration properties, and is bulky, so it tends to stick to containers, operating tools, and bent objects in the pond when handled at weirs.

"Structure of the Invention" Means for solving the problem 1: A special granular cement characterized by comprising granules of consolidated cement powder with a 0.1 to 5 positive.

2. A method for producing granular cement, which comprises compacting a mixture of cement powder and alcohol, and then crushing and drying the compacted body to diffuse the alcohol.

EXAMPLES To further explain the present invention as described above, the present invention provides granulated cement,
Moreover, instead of using water, which is commonly used as a binder for granulation, alcohols are used to prevent inorganic chemical reactions and deterioration caused by the presence of water (and carbon dioxide scum). Consolidation and granulation are carried out using the alcohol as a medium, and after the alcohol is vaporized and separated, when it is finally used, a water-use reaction with water is carried out accurately to fully demonstrate its strength. Appropriate granulation improves mixing with sand and aggregates, and as mentioned above, after the alcohol is vaporized and separated, when it encounters water, it is again dispersed in water as a fine powder, and the fine powder is dispersed in water. It is possible to form a preferable uniform cross-talk state that is equivalent to or better than that when using the above-mentioned method.

The form of the intermediate product varies depending on the specific compaction method, the amount of alcohol added, etc., and the specific growth rate varies to a certain extent, but the vaporized and separated alcohol is recovered and reused.

The size of the granules formed is generally 5 mm or less, and the particle size range is 0.1 to 5 mm, especially 0.2 to 5 mm.
Although the temperature is set at 5 mm, it is natural that there will be no problem even if some fine powder is mixed in to prevent adhesion.

Concrete fruit! One example of the embodiment is as shown step by step in Fig. 1. First, as shown in Fig. 1 (A), 14 to 20 wt of methanol is added to Portland cement or blast furnace cement.
Mixing means 11 in a suitable mixing container 1
Mix with The mixture thus obtained is then charged into a consolidation device 2 equipped with a photographing mechanism 21 as shown in FIG. If liquid is generated, remove it. The compacted compact 9 compressed into a plate shape in the compaction machine IN 2 is dried and recovered with appropriate methanol, and in its half-dried state is crushed by a crushing device 3 such as an extrusion method as shown in FIG. 1 (Q). The particles are crushed by a coarse screen 31 to a particle size of 1) 5yxm or less, and then, as shown in FIG. The obtained granular cement is then dried on a screen 32 by passing dry gas d etc. to the extent that methanol is completely diffused, and the vaporized methanol is liquefied and reused, and the obtained granular cement is sieved. The sized particles are returned to the consolidation process.

Regarding the amount of methanol added in the consolidation process, the change in shaft power in a Henschel type mixer when adding methanol liquid to cement powder and stirring is as shown in Figure 3.The shaft power changes as methanol increases. It increases with the amount of addition, reaching a peak point at an addition amount of 17.5 -, and decreases rapidly above that, indicating that the mixture becomes a slurry (a state in which methanol completely enters between the particles and there are no voids in principle). It will be done. As mentioned above, after the shaft power suddenly decreases, the liquid content (methanol) between cement powder particles simply increases and the fluidity increases, and adding more than 20 wt% is simply adding excess methanol. This only requires extra man-hours to recover methanol even during consolidation. On the other hand, 14wt rice cake corresponds to 80% of the peak point of 17.5wt%, and if it does not reach this level, plate-shaped consolidated cement will not be formed properly due to methanol shortage, and it will become loose powder or incomplete granules. As a result, the process of consolidating the kimono becomes a process loss.

Of course, if the mixture is to be consolidated under conditions where mixing is insufficient, or if the consolidation is to be made into a plate shape under conditions where there is insufficient consolidation, it will be necessary to add a little more methanol to the trap than described above, and the extent of this additional amount is not significant. proportional to the degree of sufficiency.

Through the vibration consolidation shown in Figure 1 (B), the cement is densified at the bottom of the device 2 and becomes a plate-shaped consolidated cement.This consolidation is achieved by horizontal rotation and vertical vibration, and excess methanol is poured into the upper part of the supernatant. It comes out as a liquid. The crushed particle size shown in Figure 1 (C) can be arbitrarily selected depending on the purpose of use, but the aggregate particle size when mixed as concrete is 5 to 2011.
1 (JISA5002~.rrsAsoos$), it is preferable that the particle size be below the minimum aggregate particle size in order to appropriately obtain miscibility with such aggregate. In addition to screen extrusion, crushing methods include cutting with a rotating blade. The subsequent sieving should be at the lower limit of the particle size, which does not generate μ dust or has no adhesion resistance, and is generally 0.2 fin (200 μm).

The purpose of the drying masterpiece is to recover methanol, and the drying equipment and method are arbitrary, and the pressure conditions and temperature are also selected as appropriate, and there are no particular requirements. Particles with a sieve fraction outside the range do not undergo any deterioration or reaction progress even if they encounter methanol, and the efficiency of compaction can be improved by returning them to compaction.

Another manufacturing process according to the present invention is shown schematically in FIG. 2, as shown in FIG. The 5 wt% addition mixture is charged and subjected to piston consolidation or roll consolidation.Crushing of the molded product 9a immersed by consolidation and subsequent steps 4 are shown in Figures 2 (B) and (C).
) and is the same as the case of FIG. 1 described above.

That is, in the case of compaction by external pressure such as piston compaction or roll compaction, compacted cement is formed even when the methanol concentration is about 3')lI of the above-mentioned mixing shaft power peak point of 17.5%. Also, is methanol over 17.51 voids? It is redundant because it exceeds the limit. Consolidation pressure is 2~6#
/-, the consolidation time may be instantaneous, but of course it may take some time.

The crushing of the compression molded product 9i is the same as in Figure 1, so hammering or the like can be used, and the granulation and drying treatment after crushing are the same as in Figure 1. be.

Still another consolidation molding method according to the present invention is shown in FIG. By applying dynamic or vertical vibration, a spherical consolidated cement is obtained as a molded product 9b. By using a circular or curved side wall of the pressure-molded container 2a, a sphere-shaped object 9b can be easily obtained. Among the obtained molded products 9b, the large-particle molded products sb/ are crushed, and those with a particle size of 5 dragons or less are separated into fine particles of 0.2 dragons or less, and then dried.

In molding the compacted spherical object 9b, methanol was added to 13.
If it is 1 wt% or more, the molded product 9b will be formed at the internal temperature, whereas if it is 10.5 wt% or less, no spherical product will be formed due to insufficient liquid content. Since the inner wall of the container is circular or curved, it is made into a spherical shape as in the case of horizontal silkworm movement, and the vertical vibration action causes cement attached to the inner wall of the container to fall off. The sieved particles with a size of 0.2 or less are returned to the consolidation process, which is the same as in Fig. 1.2.

Regarding the specific granular cement produced by the method shown in Fig. 1.2.4 according to the present invention, its characteristics will be compared and explained in relation to the raw material cement fine powder.
The figure shows, as an example, the particle size distribution of granular cement manufactured using the equipment shown in Figure 2.
It is clear that very uniform granules with a value of 1.96 were obtained.

In addition, the results of measuring the angle of repose, which is considered to be one of the physical property values representing the fluidity of powder and granules, are as shown in Table 1 below, even though the angle of repose of the raw material Portland cement is 52°. On the other hand, in the granular cement of the present invention manufactured using the equipment shown in Figure 2 described above, the fluidity is generally reduced to around 40°, even though there are differences depending on the particle size, and the fluidity is greatly improved. That is clear.

Furthermore, in order to compare and examine the degree of dust generation, 39 samples were placed in a 1Qcc glass cell, shaken up and down 10 times, and then mixed.
The second result of measuring the dust scattered from the cell by suctioning it for 6 seconds with a light scattering type De Notal dust meter (manufactured by Shibata Kagakuhi) is as follows.
This is the table of contents.

In other words, while raw material Portland cement required 107 seconds, granule cement took 2.3 to 0.9 seconds, which was large @
Breathability has been improved.

Such air permeability clearly indicates improved deaeration performance.

The results of the study on bulk specific gravity and degree of compression are shown in Table 4 below.

That is, compared to the raw material Portland cement, it was confirmed that the dust generation was reduced by a factor of 1:1, and the reduction in workability due to dust generation could be significantly suppressed.

In addition, we have not been concerned about the miscibility; in other words, the sample 6 was placed in a glass cylindrical cell and rotated, and the miscibility was compared based on the internal flow state, as shown in FIG. In other words, as shown in Figure 6A, the raw material Portland cement is almost completely integrated with cell 8! The granular cement according to the present invention, on the other hand, forms a laminar flow zone 1 on the surface of the sample as shown in FIG. It is clear that it shows good miscibility.

Next, we examined the air permeability and compared the air permeability of the samples using a plain air permeation mechanism, and the results were as shown in the third article.
That is, a 2.92p sample was consolidated to a porosity of 0.5, and the specific gravity was 0.
．． Comparisons were made based on the time required for air to pass through a head of 7 (log) with a manometer of 8.

That is, by making the granular cement according to the present invention, the loose bulk specific gravity is significantly increased to about 40 inches, the bulk during rough filling is improved, and the compaction is also significantly reduced, making it easier to handle during handling. Changes in bulk are reduced, and since the bulk specific gravity has increased as mentioned above, degassing performance during rough filling has been improved.

The compressive fd strength of the granular cement of the present invention as described above is as shown in Fig. 7, and is 0.3/cd for the type shown in Fig. 1 and 0.4 to 0 for the type shown in Fig. 2. At .55#/-, it can adequately withstand stacking pressures of 2 to 3 rIL. Furthermore, according to the test method specified in JIS for these granular cements, there is no deterioration in hydration reaction, strength development, or other quality even after 1 lIf.

``Effects of the Invention'' The present invention as explained above improves the effective pressure of the conventional building cements, such as application, pouring, fluidity, mixability, degassing properties, and adhesion resistance, making them easier to handle. It is an invention that is industrially highly effective, as it can improve workability as well as improve productivity.

[Brief explanation of the drawing]

The drawings show the technical contents of the present invention, and FIG. 1 is an explanatory diagram showing one example of the manufacturing process in the present invention, and FIG.
The figure is an explanatory diagram similar to Figure 1 showing another example, Figure 3 is a diagram showing the relationship between the amount of methanol added and the shaft power (load) of the mixer groove, and Figure 4 is a diagram showing the relationship between the amount of methanol added and the shaft power (load) of the mixer groove. Fig. 5 is a diagram showing the particle size distribution of the granular cement according to the present invention according to the manufacturing process shown in Fig. 2, and Fig. 6 is an explanatory diagram of another manufacturing process. Figure 7 shows a comparison of the mixing properties of cement, and Figure 2 summarizes the compressive strength measurement results for granular cement according to the present invention. However, in these drawings, 1 is a mixing vessel. J12 is a compacted container, 3 is a crushing device, 4 is a sieve vj structure, 5 is a compression cell, 6 is a sample, 13m is a block sample, 7 is a laminar flow region, 8 is a fluidity test cell, 9.9a , 9b indicates a compacted compact. Patent Applicant: Nippon'Af Stock Company T7 Inventor: Tetsu Akaishi Taira Daido Takahata - Bema
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Claims (1)

[Claims] 1. Particle size of consolidated cement powder of 0.1 to 5 mm
A granular cement characterized by being composed of granules. 2. A method for producing granular cement, which comprises compacting a mixture of cement powder and alcohol, and then crushing and drying the compacted body to diffuse the alcohol.