JP2000212545A - Static fracturing agent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a static fracturing agent capable of keeping working hours of slurries and presenting sufficient fracturing effects in a short time (within 10 hours) even used at low temperatures (about 5 deg.C). SOLUTION: This static fracturing agent comprises a cement intermediate processing product obtained by heating a raw material mixture for producing clinker at 800-1100 deg.C in a portland cement clinker manufacturing process and a water reducing agent. The cement intermediate processing product is preferably one preparatively separated from a suspension preheater.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rock or concrete static crushing agent mainly used in the civil engineering and construction industries.

[0002]

2. Description of the Related Art Heretofore, rocks or concrete are made with holes in advance, and a slurry in which a powdery expansive crushing agent and water are kneaded is filled in the holes, and the slurry is generated in the process of hydration. A so-called static crushing method in which crushing is performed by expansion force is known. As the characteristics required for the powdery expansive crushing agent (so-called static crushing agent) used in the static crushing method, a slurry obtained by kneading the static crushing agent and water is poured into rock or concrete. Work time to fill holes can be secured. The crushing work can be completed in as short a time as possible. Is mentioned.

By the way, since quick lime has a large expansion force during hydration, it has been conventionally proposed to use it as a static crushing agent. As an example of such a static crushing agent using quick lime, for example, in JP-A-57-190657, a CaO crystal 15 obtained by firing at a temperature of 1200 ° C. or higher is used.
97 comprises a weight percent and 3CaO · SiO ₂ crystal 3-85 wt%, C
clinker whose aO crystal is not included in 3CaO ・ SiO ₂ crystal
90-99% by weight and the rest of the mixture of gypsum 10
A crushed material in which 0.5 to 4 parts by weight of a cement water reducing agent is added to 0 parts by weight and mixed is disclosed.

[0004]

Problems to be Solved by the Invention
In the crushed material described in Japanese Unexamined Patent Publication (Kokai) No. 6-264, the working time of the slurry can be secured, and when the material is used at about 20 ° C., a short time (6 to 1
The crushing operation can be completed in about 2 hours). However, there is a problem that when used at a low temperature (about 5 ° C.), it takes a long time to crush (about 12 to 24 hours).

[0005] Therefore, the present invention can ensure the working time of the slurry and can use the slurry for a short time (1
It is an object of the present invention to provide a static crushing agent capable of obtaining a sufficient crushing effect within 0 hours).

[0006]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, if a specific powder obtained in the Portland cement clinker manufacturing process and a water reducing agent are combined, the working time of the slurry can be reduced. The present inventors have found that a sufficient crushing effect can be obtained in a short time (within 10 hours) even when used at a low temperature (about 5 ° C.), and the present invention has been completed.

That is, according to the present invention, a raw material mixture for clinker production is used in a portland cement clinker production process.
A cement intermediate process product obtained by heating to 0 to 1100 ° C.,
A static crushing agent containing a water reducing agent (Claim 1).
The static crushing agent according to claim 1 (claim 2), wherein the cement intermediate process product is fractionated from a suspension preheater.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail. First, a cement intermediate process product (hereinafter, referred to as a cement intermediate process product) obtained by heating a raw material mixture for clinker production to 800 to 1100 ° C. in a Portland cement clinker production process used in the present invention will be described. In the Portland cement clinker manufacturing process, as shown in FIG.
Cyclones 5, 6 in multiple stages (FIG. 1 shows an example of four stages)
7 and 8 and a calcining furnace 9 (the calcining furnace 9 may not necessarily be provided), and the exhaust gas from the rotary kiln is supplied to the calcining furnace 9 and the cyclones 8, 7, 6, 5, in that order. It has become so. In the present invention, the suspension preheater also includes a pipe connecting the lowermost cyclone (cyclone 8 in FIG. 1) to the kiln tail. Cement clinker raw material composed of limestone, clay, silica stone, iron raw material and the like is supplied from the raw material storage 1 to the uppermost cyclone 5 of the suspension preheater via the raw material dryer 2, the raw material crusher 3, and the raw material tank 4, It moves to cyclones 6, 7, and 8 in order, and is heated to 800 to 1100 ° C. until it reaches the lowermost cyclone 8, and is a cement intermediate process product. In the present invention, it is preferable that the cement intermediate process product is separated from the suspension preheater in terms of productivity and cost. In addition, the fractionation of the cement intermediate process product is performed by a fractionation damper.
You can extract from 20. In the present invention, it is preferable to use a cement intermediate process product obtained by heating a raw material mixture for producing an early-strength Portland cement clinker and a normal Portland cement clinker.

[0009] The cement intermediate process product has a Blaine specific surface area of about 3500 to 6000 cm ² / g, and quicklime (soft-burnt quicklime).
Contains 40-60% by weight and gypsum 5-10% by weight in terms of SO ₃ (Others include some calcium aluminate or calcium silicate and unreacted cement raw materials (clay, silica, iron raw materials) Out).

It is said that most of the SO ₃ in the firing zone (steps 5 to 10 in FIG. 1) in the Portland cement clinker manufacturing process exists as a sulfate melt and is volatilized as SO ₂ at the same time. The oxygen partial pressure in the firing zone is less to facilitate volatilization of SO ₂ produced by the decomposition. It is said that these volatilized SO ₂ selectively aggregate at 550 to 1150 ° C. into fine particles having a large specific surface area. And in the said cement intermediate process product, since a soft-burnt lime is many in a fine particle component, many gypsum exists on the surface of a soft-burnt quick-lime particle. For this reason, when the cement intermediate process product is kneaded with water, ettringite covers the surface of the soft-burned quick lime particles in the early stage of hydration, so that the hydration of the soft-burned quick lime is suppressed and the working time is secured. After that, soft calcined lime with high hydration activity reacts, and low temperature (5 ℃
), A sufficient crushing effect can be obtained in a short time.

If the heating temperature of the raw material mixture for clinker production is less than 800 ° C. in the cement intermediate process product, the amount of soft-burnt lime is small, so that a large expansion force cannot be obtained, and it is difficult to obtain a sufficient crushing effect. Become. On the other hand, when the heating temperature of the raw material mixture for clinker production exceeds 1100 ° C., the generation of calcium silicate or the like becomes large, or hard-burnt quicklime is generated, and the amount of soft-burnt quicklime decreases, so that a large expansion force cannot be obtained. , It is difficult to obtain a sufficient crushing effect.

The water reducing agent used in the present invention has a function of improving the fluidity of a kneaded material using cement to reduce the amount of water, and is a water reducing agent generally used for concrete. Can be used.
Specific examples include naphthalenesulfonic acid-based, melamine-based, polycarboxylic acid-based, aminosulfonic acid-based fluidizing agents, water reducing agents, high-performance water reducing agents, high-performance AE water reducing agents, and the like. But it can be used.

[0013] The amount of the water reducing agent used is 10
The amount is preferably 0.5 to 3 parts by weight, more preferably 1 to 2 parts by weight, based on 0 parts by weight in terms of solid content. The amount of water reducing agent used is 0.5
If the amount is less than the weight part, the amount of water increases, so that a large expansion force cannot be obtained, and it is difficult to obtain a sufficient crushing effect. If the amount of the water reducing agent exceeds 3 parts by weight, the hydration of the soft burnt lime is delayed, so that it is difficult to obtain a sufficient crushing effect, and it takes time to crush.

In the use of the static crushing agent of the present invention, the slurry may be kneaded with water and poured into a hole formed in rock or concrete. In this case, the ratio of water to 100 parts by weight of the static crushing agent is preferably 30 to 40 parts by weight in consideration of workability and crushing effect. The procedure for kneading the materials is not particularly limited, and the materials may be put together in a mixer and kneaded, or water in which a water reducing agent has been dissolved in advance and kneaded with the cement intermediate process product may be used. Alternatively, the powdery water reducing agent and the cement intermediate process product may be mixed in advance and kneaded with water. As the kneading device, any existing stirring device can be used, and for example, a Hobart mixer, a tilting mixer, an omni mixer, or the like can be used.

[0015]

Test Examples Hereinafter, the present invention will be described with reference to test examples. 1. Materials used The following materials were used. Cement intermediate process product A: Suspension preheater (heating temperature 800-900 ° C) in the ordinary Portland cement clinker manufacturing process
(Taiheiyo Cement Co., Ltd. factory, Blaine specific surface area 5000 cm ² / g) B: Suspension preheater (heating temperature 600-700 ° C) in the ordinary Portland cement clinker manufacturing process
(Taiwan Cement Co., Ltd. factory product, Blaine specific surface area 3300 cm ² / g) C: Suspension pre-heater (heating temperature 1160-1180) in normal Portland cement clinker manufacturing process
° C) (product of Taiheiyo Cement Corporation factory,
Brain specific surface area 4000 cm ² / g) High-performance water reducing agent A: "Mighty 150" (manufactured by Kao Corporation) B: "NT-1000S" (manufactured by NMB Corporation) Water: tap water

The cement intermediate process product, the high-performance water reducing agent and water were kneaded using a mortar mixer at 20 ° C. for 60 seconds according to the composition shown in Table 1. The slurry is mixed for 15 minutes.
After standing still at 20 ° C., the mixture was poured and filled into a hole of φ4 × 55 cm in depth of a 60 × 60 × 60 cm uncured concrete hardened material. Thereafter, the crushing time at 5 ° C. was measured. Table 1 shows the results.
It is described together.

[0017]

[Table 1]

As is apparent from Table 1, the cement intermediate process product (the raw material mixture for clinker production in the Portland cement clinker production process) specified in the present invention is 800-110.
In the case of Test Examples 1 to 3 in which a mixture obtained by heating to 0 ° C.) and a water reducing agent were combined, a sufficient crushing effect was obtained within 10 hours. On the other hand, in Test Examples 4 and 5 using cement intermediate process products other than those specified in the present invention, crushing was not possible.

[0019]

As described above in detail, in the Portland cement clinker manufacturing process, the cement intermediate process product obtained by heating the clinker manufacturing raw material mixture to 800 to 1100 ° C., and the present invention comprising a water reducing agent Static crushing agent can ensure the working time of slurry and low temperature (5
(Approx. ° C.) even when used in a short time (within 10 hours).

[Brief description of the drawings]

FIG. 1 is a view schematically showing a process for producing a cement intermediate process product according to the present invention.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 raw material storage 2 raw material dryer 3 raw material crusher 4 raw material tank 5,6,7,8 cyclone (suspension preheater) 9 calciner 10 rotary kiln 20 preparative damper

Claims (2)

[Claims] 1. A static crushing agent comprising a cement intermediate process product obtained by heating a raw material mixture for clinker production to 800 to 1100 ° C. in a Portland cement clinker production process, and a water reducing agent. 2. The static crushing agent according to claim 1, wherein the cement intermediate process product is fractionated from a suspension preheater.