JPS58154779A - Breaking agent for brittle substance - Google Patents

Abstract

PURPOSE:To provide a breaking agent which contains pulverized surface carbonate of mildly burnt quick lime, hydraulic substance and cement dehydrating agent, requies no addition of hydration suppressor, has high fluidity and breaks brittle substances in a short period of time even in summer season. CONSTITUTION:The breaking agent used for breaking brittle substances (e.g. rock or concrete) is prepared by adding 0.5-3pts.wt. cement dehydrating agent (e.g. consisting mainly of calcium ligninsulfonate, etc.) to 100pts.wt. main component consisting of 50-95wt% mildly burnt CaO powder with a crystal diameter of 10mu or smaller and surface coated with a thin CaCO3 film and 50-5wt% hydraulic substance (e.g. ordinary Portland cement or ultra-quick curing cement). It requires no addition of hydration suppressor, has high fluidity and produces a slurry which shows a high expansion pressure at a high temperature. So it can break brittle substances in a short time even in summer season.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a crushing agent for brittle objects such as rocks and concrete.

Conventionally, as a method for crushing brittle objects, many methods containing quicklime have been proposed, for example, as described in Japanese Unexamined Patent Publication No. 56-6705. As for the quality of the quicklime, -y is required to have high purity of CaO and slow reaction with water. This reactivity with water depends on the firing conditions of the limestone when producing quicklime, and soft-burnt products obtained by firing at low temperatures and in a short time react quickly with water, so they are used as crushing agents. If this occurs, the material paste will immediately expand due to water use, and the softness of the material paste will drop rapidly, making it difficult to work.

As a result of various studies aimed at solving the shortcomings of such crushing agents mainly composed of quicklime, the present inventor found that if a mixture containing mainly CaO particles coated with a CaCO3 thin film layer is used, We have completed the present invention by discovering that the water utilization reaction can be easily controlled even in the summer when temperatures are above 25C, allowing for sufficient crushing.

That is, according to the present invention, 0.00 parts by weight of a cement water reducing agent is added to 100 parts by weight of a main material consisting of 50 to 95% by weight of surface carbonates and 50 to 5% by weight of hydraulic substances of soft calcined quicklime powder having a crystal diameter of less than 10 μm. This is a crushing agent for brittle objects containing 5 to 3 parts by weight.

The present invention will be explained in detail below.

The present invention contains a surface carbonate of soft burnt lime having a crystal size of less than 10 μm, a hydraulic substance, a cement water reducing agent, and if necessary, a cement water usage inhibitor.
The main material is 50 to 95 1% by weight of surface carbonated soft burnt lime and 50 to 5 % by weight of hydraulic substances. By using carbonated soft calcined lime as the main component, there is an advantage that the hydration reaction can be easily controlled without the need for adding a hydration inhibitor.

The degree of carbonation of soft calcined lime powder increases as it increases.
It is possible to suppress the hydration reaction of quicklime, but on the other hand, the swelling force is reduced, so it is desirable that the surface of the soft-burned quicklime powder be coated thinly with calcium carbonate. To obtain such a product, soft calcined lime with a crystal diameter of less than 10 μm obtained by calcining limestone is crushed, placed in a container, and contacted with CO2 scum for about 0.5 to 10 hours.

In the present invention, the reason why the crystal size of soft calcined lime is limited to less than 10μ is that hard calcined lime with a crystal size of 10μ or more is not only difficult to carbonate, but also because the activity of the lime surface is destroyed. This is because even if carbonated, the hydration reaction is significantly slowed down.

Hydraulic substances include various types of Portland cement such as ordinary Portland cement, ultra-fast hardening cement, alumina cement, and even lime and bauxite, which can be obtained by blending a predetermined amount of lime and bauxite, melting at 100C to 1600C, and then cooling. For example Cl2A7, C3A, CA
, C, , A7CaF2 alone or a mixture of these and anhydrite can be mentioned.

In the present invention, the reason why the ratio of the main material is specified as described above is that if the surface carbonate of soft calcined lime powder with a crystal diameter of less than 10μ is less than 50% by weight, the expansion pressure becomes small and crushing takes too much time. In addition, if the content exceeds 95%, the digestive reactivity of quicklime increases, and even if the crushing agent is injected into a hole in a brittle object as a slurry, the expansion pressure ejected from the injection port is unlikely to cause skin crushing. It is. A preferable ratio is surface carbonate of soft calcined lime powder with a crystal diameter of less than 10μ.
0-70% by weight, and 50-30% by weight of hydraulic material.

In other words, even if the crushing agent slurry using the main material limited in the present invention is injected into the perforation of a brittle object, a large expansion pressure can be obtained without ejecting from the injection port. This is because a large frictional force is generated between the crushing agent hydrate produced by the self-hardening property of the hydraulic substance and the wall surface of the hole serving as the injection port, thereby preventing ejection.

The particle size of the carbonated soft calcined lime and the hydraulic substance that constitute the main material of the present invention is 2000 to 5 in Blaine value, respectively.
000crn2//1 is used as a crushing agent, it is 2500 to 50006n! /P. If the particle size of these components is too coarse, material separation will occur, and if the particle size is too fine, the expansion pressure will become low, which is not preferable.

In the present invention, 100 parts by weight of the above main material and no cement water reducing agent are added.
．． 5 to 6 parts by weight are present.

The cement water reducing agent is preferably a so-called high-performance water reducing agent, and specifically, lignin sulfonate type, water-soluble melamine resin type, higher polyhydric alcohol sulfonate type, and β-naphthalene. One (5) or more species such as sulfonate formalin condensate systems are used. By adding 0.5 to 3 parts by weight of this to the weight of the main material 1[]01, the fluidity can be greatly improved and the water ratio can be reduced, increasing the expansion pressure.
-14 Can be made powerful. That is, if the proportion of the cement reduction/water agent is less than 0.5 parts by weight, such an effect will be small, and if it exceeds 6 parts by weight, the water reduction effect will not improve significantly, which is uneconomical. The preferred proportion of cement water reducer is 1 to 2 parts by weight.

Although it is not necessary to add a hydration inhibitor to the crushing agent of the present invention, it may be used in an amount of at most 2 parts by weight per 100 parts by weight of the main material. The hydration inhibitor is selected from commonly known ones, such as inorganic carbonates such as potassium carbonate and soda carbonate, and organic hydroxycarboxylic acids or their salts such as citric acid, tartaric acid, sodium citrate, and sodium gluconate. One or more types can be listed.

By using the above-described crushing agent of the present invention, it is possible to prepare a slurry that has excellent fluidity and exhibits high expansion pressure even at high temperatures without requiring a water usage inhibitor (6). It has the effect of crushing brittle objects in a short time. That is, the conventional crushing agent required at least 5 parts by weight of a hydration inhibitor, but even then, sufficient crushing work could not be carried out in the summer. However, the product of the present invention makes this possible without requiring a hydration inhibitor.

Hereinafter, the present invention will be explained in more detail with reference to examples.

Example 1 Soft calcined lime with a crystal diameter of less than 10μ was subjected to Blaine specific surface area filtering.
000 cm2/g- and brought into contact with CO2 scum for 1.5 hours to obtain quicklime powder whose surface was carbonated. This stuff is 60% by weight and 12CaO 71Q2
0. Amorphous calcium aluminate with the composition of ■
To 100 parts by weight of the main material consisting of 40% by weight of a hydraulic substance consisting of an equal weight mixture of molded anhydrite, a commercially available 7-ment water reducing agent (based on calcium ligninsulfonate) was added.
1 part by weight (trade name: "Ultra Gin") was blended to prepare a crushing agent. 100 parts by weight of this crushing agent was mixed with 65 parts of water to form a slurry, and the pot life at a room temperature of 20 C was measured to be 14 minutes, and the expansion pressure was measured at a room temperature of 25 C for 12 hours. Tokoro 4400 t/m
It was 2.

Note that the pot life was determined by measuring the time required from pouring water until the fluidity disappeared. In addition, the expansion pressure was determined by welding a steel plate to the bottom of a carbon steel pipe for piping with an inner diameter of 66 mm and a height of 600 m.
The slurry was injected into a steel pipe to which a paper strain gauge with a gauge length of 10 m was attached in the circumferential direction at the center of the height of the surface, and the strain was calculated from the strain of the steel pipe when it was left standing.

Example 2 In Example 1, when 1 part by weight of a hydration inhibitor was added to the crushing agent, the pot life was 50 minutes and the expansion pressure was 4270 t/m2. , the hydration inhibitor used was potassium carbonate redundant weight%,
It is a mixture of 13% by weight of curconic acid sorter and 17% by weight of citric acid.

Example 6 The pot life and expansion pressure were measured in the same manner as in Example 2, except that the composition ratio of the main material was changed.

The results are shown in Table 1.

1. Pot life and expansion pressure were measured in the same manner except that the surface contact time was changed. The results are shown in Table 2. In addition, in this table,
The results of an analysis of the amount of CO2 contained in soft burnt lime are also shown.

(9) Example 5 In order to evaluate the performance of the crushing agent, a hardened mortar body with a diameter of 15 m and a height of 6° α (compressive strength of 506 ktf/cm2, tensile strength of 62 ktf/cm) was prepared with a diameter of 28 ta in the center.
The slurry prepared in Examples 1 to 4 was injected into the hole x and left at room temperature of 25C. As a result, the time required for crushing was 100 minutes for the crushing agent of Example 1, and the time required for crushing was as shown in Tables 1 and 2 for the other crushing agents.

Patent applicant: Denki Kagaku Kogyo Co., Ltd. (10)

Claims (1)

[Claims] 0.5 to 3 parts by weight of a cement water reducing agent to 100 parts by weight of the main material consisting of 50 to 95% by weight of surface carbonates and 50 to 5% by weight of hydraulic substances of soft calcined lime powder with a crystal size of less than 10μ.
A crushing agent for brittle objects containing part by weight.