JPS62149783A - Crushing agent - Google Patents

Abstract

PURPOSE:To contrive consistent improvement in the effect of a crushing agent, by removing soft-burned quicklime particles contained in a raw material of a hard-burned quicklime. CONSTITUTION:A crushing agent composed mainly of a hard-burned quicklime obtained by burning a raw material of a hard-burned quicklime at 1,300-1,500 deg.C and removing the soft-burned quicklime portion contained therein. Preferably, after removing the soft-burned quicklime portion, the hard-burned quicklime is ground to a powder having a specific surface area of 1,500-4,000cm<2>/g, and then 100pts.wt. of this ground material is mixed with 0.3-8pts.wt. water-reducing agent, 0.2-7pts.wt. gypsum, and 0-70pts.wt. admixture to form a mixed powder. As the water-reducing agent, particularly the one referred to as a high- performance water-reducing agent, while fly ash are preferably used as the admixture.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a crushing agent for rocks, concrete structures, etc.

[Prior Art 1] Many crushing agents have been proposed that utilize the swelling force of quicklime due to hydration. There are two manufacturing methods: one uses quicklime made by adding various additives to limestone and calcining it at high temperature, and the other uses commercially available quicklime as the raw material.The former has high production costs, while the latter has stable product performance. Lacking sex.

[Object of the Invention] The object of the present invention is to improve the above-mentioned drawbacks caused by quicklime and to provide a crushing agent that exhibits stable and excellent effects.

[Problem 1 to be solved by the invention Quicklime used as a crushing agent is generally hard calcined lime with a slow hydration reaction, but the degree of calcination of commercially available hard calcined lime is unstable, and some There is a mixture of soft calcined lime parts that react quickly in the water phase, and even within the same lot, the activity value (10 minutes value of 100g method according to the Japan Lime Association reference test method) varies from 20 to 500 degrees. It is an aggregate of particles with a non-uniform firing degree. The particles of soft-burned quicklime are softer than those of hard-burned quicklime, so when the hard-burned quicklime raw material is crushed in a ball mill, the soft-burnt quicklime particles are over-pulverized, so the crushing agent is When used as a raw material, the hydration reaction of soft calcined lime powder is extremely fast, and the heat of hydration at that time also accelerates the hydration reaction of hard calcined lime powder, which solves the problem that it is difficult to adjust the hydration reaction rate. This is what I am trying to do.

[Means for Solving the Problems] The present invention removes the soft calcined lime mixed in the lumpy hard calcined lime raw material to produce a crushing agent containing only the hard calcined lime as the main raw material.

That is, so-called hard calcined lime, which is made by calcining lump quicklime at 1,300 to 1,500°C, is used as a raw material, and hard calcined lime particles and soft calcined lime particles are sorted using differences in color and crushability. , which extracts only hard-burned quicklime.The method is (1) Focusing on the fact that soft-burnt quicklime particles are softer than hard-burnt ones, the hard-burnt quicklime raw material is coarsely crushed through a 10 # sieve. ,1
Remove particles that pass through a ~5M sieve.

(2) Focusing on the fact that soft calcined lime particles are whiter in color than hard calcined lime particles, relatively white particles from hard calcined lime particles are removed.

(3) Focusing on the fact that hard-burned quicklime particles are darker (colored) compared to soft-burnt ones, only the relatively dark-colored particles are extracted from the hard-burnt quicklime.

The above three weighing methods are listed. The hard calcined lime raw material used in the above operation has an activity value of 250 d in the reduced sample.
The following are preferred. This is because the efficiency of the above operation deteriorates.

Regardless of which of the three methods mentioned above, the quicklime that has been subjected to the operation has a smaller range of fluctuation in activity compared to the hard-burned quicklime before the operation, and the hydration reaction of the crushing agent that is the crushed product. Stabilize speed.

The specific surface area (Blaine method) of the quicklime obtained in the above procedure was 1
500~4000ci/! 7, and the pulverized product 100
Water reducing agent: 0.3 to 8 parts by weight, gypsum: 0.2 to 8 parts by weight
Add 7 parts by weight and 0 to 10 parts by weight of admixtures,
Mix to obtain the desired crushing agent. By controlling the above-mentioned formulations, a crushing agent suitable for the operating temperature and pore size can be obtained.

The fineness of the crushed material greatly affects the performance of the crushing agent, and crushing agents with a high degree of fineness, that is, those obtained by finely pulverizing, have a relatively fast hydration reaction and are difficult to drill into the crushed material when made into an aqueous slurry. Since the time required to maintain fluidity sufficient to fill the pores (hereinafter referred to as pot life) is short and the hydration reaction is rapid, there is also a risk of bumping due to heat generation. The crushing agent obtained by coarsely crushing the crushed material has a relatively slow hydration reaction.
After filling the pores of the material to be crushed as an aqueous slurry, the development of expansion pressure is slow, so it takes a long time to crush the material, which is inappropriate. Therefore, the fineness of the quicklime in the present invention is preferably such that the specific surface area is 1500 to 4000 cr/'j.

As the water reducing agent, any commercially available water reducing agent for cement can be used, but those called high performance water reducing agents are particularly preferred. By using this high-performance water reducing agent, when the crushing agent is made into an aqueous slurry, it is possible to reduce the mixing ratio of water and the crushing agent, which not only improves expansion properties but also improves expansion properties.
It delays the hydration reaction of the aqueous slurry and allows it to have a suitable pot life. The appropriate amount of addition is 0.3 to 8 parts by weight (per 100 weight of hard calcined lime particles) in order to suppress the hydration reaction of the crushing agent slurry and delay and lower the expansion pressure. It is.

Gypsum is used as a retardant for the hydration reaction of the crushing agent, and any type of gypsum, including anhydrous, semi-hydrated, and gypsum, can be used because it has a retarding effect. The hydration reaction of quicklime powder can also be suppressed by a water reducing agent as described above, but gypsum suppresses the hydration reaction of the crushing agent slurry without reducing the swelling pressure compared to the water reducing agent.

The amount added is 0.00% per 100 parts of hard calcined lime powder.
2 to 7 parts by weight is suitable.

Mixed materials are used when the crushing agent is used when the temperature of the material to be crushed is high, such as in spring, autumn, or summer, or when the pore size used is large, because the hydration reaction of the crushing agent slurry cannot be controlled with water reducing agents or gypsum. It is added to reduce the quicklime content in the crushing agent and to reduce and adjust the ω of the hydration reaction. The addition of a flooding agent, which is inexpensive compared to quicklime, significantly lowers the manufacturing cost of the crushing agent than the addition of relatively expensive agents (water reducers, retarders, etc.) to control the hydration reaction. be able to. Quicklime filler, silica powder, slag powder, fly ash, etc. can be used as the mixing material, but they improve the fluidity of the crushing agent slurry, have an appropriate retardation effect on the hydration reaction, and do not require pulverization. It is preferable to use fly ash.

However, the crushing agent to which fly ash is added also has the effect of reducing the risk of condensation and bumping after the slurry is filled. The amount added varies depending on the temperature of the material to be crushed, the pore diameter, etc., but it is suitably in the range of 0 to 70 parts by weight per 100 parts by weight of hard calcined lime powder.

As mentioned above, in the present invention, the rate of the hydration reaction of quicklime is stabilized by removing the soft-burned quicklime particles in the hard-burned quicklime raw material, and the fineness of the quicklime is adjusted depending on the temperature and pore size of the material to be crushed. The desired crushing agent is obtained by adjusting the amounts of the water reducing agent and retarder, and the amount of the mixing material.

Since the present invention has the above structure, the crushing agent 1 of the present invention
A slurry made by adding 20 to 40 parts by weight of water to 00 parts by weight is injected into a hole drilled in a brittle object, and the brittle object is crushed by using the expansion caused by the hydration reaction of quicklime while standing. I can do it. The time required from injection to crushing is usually 10 to 24 hours, but it is necessary to consider the hole diameter and temperature of the object to be crushed.

[Example] (A) A lumpy hard calcined lime raw material (activity test of 1-minute sample - 250 d or less in 10 minute value) is coarsely crushed to a 10 mm through-hole particle size, and then sieved under a 1-5M sieve. Remove and crush.

(B) The relatively white grains are removed from the lumpy hard calcined quicklime raw material (same as in the previous step), and the resulting material is pulverized.

(C) Only the relatively black grains of the hard calcined lime raw material in (8) above are taken out and pulverized.

To 100 parts by weight of hard calcined lime powder obtained by any of the above methods (A), (B), and (C), 0.3 to 8 parts by weight of Melment (manufactured by Showa Denko) as a water reducing agent, anhydrous.
By adding and mixing 0.2 to 71 parts of gypsum and 0 to 70 parts by weight of fly ash, the desired powder is obtained.

(1) About crushing agent performance confirmation test method a. Measurement of expansion pressure JIS G 3454 Carbon steel pipe for pressure piping 40 ASCII 80 to 30 c
Attach paper strain gauges at two locations along the outer circumference of a pipe cut to a length of m, and use hydraulic pressure to determine the conversion coefficient of internal pressure due to external strain.Attach a bottom cover to one end of the pipe, with the opening facing up. Put the specified amount of water into a container, pour the specified amount of crushing agent into the container through the opening of the pipe, and pour the specified amount of crushing agent into the container through the opening of the pipe. The strain of the pipe was measured over time, and the expansion pressure (
Calculate Kg f / cti ).

At this time, the temperature of the outer wall of the pipe is also measured. A small hole in a brittle object (φ35-50 mm) As a crushing agent, it is desirable that the expansion pressure after 24 hours is 250/(gf/cm or more and the temperature upper limit due to heat generation is 10°C or less).

b. Stability of commercially available quicklime Commercially available hard-calcined quicklime produced by a continuous firing method with a calcination zone temperature of 1,300 to 1,500°C as described above (A).
The results of measuring the activity values (condensation sample - 10 minute value) of those sorted by each method of , (B), and (C) and those that were not sorted (no sorting) were as shown in Table 1. .

Table 1 Example 1 The raw materials of samples NQ 1 to 4 in Table 1 above were pulverized as shown in Table 2, and Melment (mentioned above) and CaSO4 were added to 100 suspended parts of the obtained powder in a second The crushing agent was added in the proportion shown in the table and homogenized to give 14 ml of the crushing agent. The expansion pressure of 1 q of slurry prepared by kneading 100 parts by weight of the obtained crushing agent and 30 small parts of water was measured in a thermostatic chamber at 5°C. The results are shown in Table 2.

Example 2 Samples Nα1 to Nα1 to N (14) in Table 1 above were pulverized as shown in Table 3, and Melment (mentioned above), CaSO4, and fly ash were added to 100 parts by weight of the resulting powder. They were added in the proportions shown in Table 3 and homogenized to obtain a crushing agent.

The resulting slurry was added at a ratio of 100 parts of crushing agent to 30 parts of water and kneaded, and the expansion pressure of the resulting slurry was measured in a thermostatic chamber at 20°C. The results are shown in Table 3.

Example 3 The raw materials of samples Nα1 to Nα4 described above were pulverized as shown in Table 4, and Melment (mentioned above), Ca SO4, and fly ash were added to 100 m parts of the obtained powder in the amounts shown in the table. It was added in 91 cups and homogenized to obtain a crushing agent. This thing 1
Table 4 shows the results of measuring the expansion pressure of the slurry obtained by adding and kneading 30 parts by weight of water to 00 parts by weight in a thermostatic chamber at 30°C.

In Test 13 in the table, there were two bumping phenomena and the maximum temperature was high, making it dangerous and unsuitable as a crushing agent.

Example 4 Unreinforced concrete specimen (600aa+
m x 600mmz material age 33 days, compressive strength 315Kgf
/ci, tensile strength 24Ky f/cd) hole in the center of the top surface (hole diameter 3811IIll, depth 550mm)
was drilled. After placing this specimen in a constant temperature room at 20°C (±2°C) for one week, the hole was
A slurry obtained by mixing 30 parts by weight of water with 100 mm parts of the crushing agent shown in was filled, and a crushing test was conducted.

About 11 hours after the sample was filled with the slurry, cracks appeared in the upper hole, and after about 22 hours of contact, cracks appeared from the top to the bottom.
The rift widened and divided the marriage.

[Effects] In the present invention, the crushing agent is produced by using only the hard calcined lime part obtained by calcining lump limestone and removing the soft calcined lime part contained therein. The crushing agent has this hard calcined quicklime as its main component. This product is inexpensive and has stable performance.

There are two types of quicklime used in the production of crushing agents, one of which is powdered limestone containing impurities (SiO, Fe).
2O2, AJ1203, etc.) is added and fired to obtain quicklime with a uniform and stable hydration reaction rate, and this quicklime is used as a crushing agent. Limestone at a relatively high temperature 1,300 to 1,50
It uses quicklime obtained by baking at 0°C), and the former quicklime has stable hydration reactivity but is very expensive to produce; the inoculated quicklime has a low production cost; When using quicklime as a crushing agent, various operations are required (such as adding chemicals and water when crushing quicklime).

Among these, the present invention stabilizes the hydration reactivity of the latter quicklime through a simple operation and then crushes it, and adds relatively inexpensive additives and mixtures to achieve inexpensive and stable performance. As shown in the example, it is a crushing agent that acts as a crushing agent.

Claims (2)

[Claims] (1) A crushing agent whose main component is hard-burned quicklime obtained by removing the soft-burnt lime contained in the hard-burnt quicklime raw material baked at 1,300 to 1,500°C. (2) The hard calcined quicklime after removing the soft calcined quicklime portion is pulverized to a specific area of 1500 to 4000 cm^2/g, and 0.3 to 8 parts by weight of a water reducing agent per 100 parts by weight of the hard calcined quicklime;
The crushing agent according to claim 1, characterized in that it consists of a mixed powder of 0.2 to 7 parts by weight of gypsum and 0 to 70 parts by weight of a mixed material.