JPH08245245A - Production of cement product - Google Patents

Abstract

PURPOSE: To obtain a technique for improving the regeneration efficiency of excess cement materials while maintaining the strength of cement products at a specified or higher level. CONSTITUTION: Cement raw materials 1 contain cement blank materials 6 mainly composed of cement and the excess cement materials 4 before curing which are generated in the production processes for the cement products in producing the cement products by molding and curing these cement raw materials 1. This process for producing the cement produces comprises preparing the cement raw materials 1 by mixing the excess cement materials 4 into the cement blank materials 6 in the slurry state obtd. by supplying an oxycarboxylic acid and water to the excess cement materials 4.

Description

Detailed Description of the Invention

[0001]

INDUSTRIAL APPLICABILITY In the present invention, when a cement raw material is molded and hardened to produce a cement product, the cement raw material is produced in a cement raw material mainly composed of cement and a cement product manufacturing process. The present invention relates to a method for producing a cement product including a cement surplus material before hardening.

[0002]

2. Description of the Related Art Conventionally, in this type of cement product manufacturing method, water is added to the cement surplus material to form a slurry as it is and mixed with the cement base material to prepare a cement raw material. It was being appreciated.

[0003]

However, according to the above-mentioned conventional method for producing a cement product, the cement residual material before curing generated in the process for producing the cement product is regenerated,
Since it can be used as a cement raw material, the raw material of the cement can be conserved and the cost of the cement raw material can be saved accordingly, but the cost of the cement product can be reduced. However, the strength of the obtained cement product is produced only from the cement raw material. There is a problem that the strength is lower than the strength of the cement product. Therefore, in order to keep the strength of cement products above a certain level, the amount of recycled cement surplus material is limited.Therefore, a technology to improve the efficiency of recycling cement surplus materials while keeping the strength of cement products above a certain level. Was desired.

[0004]

[Means for solving the problem] Molding cement raw materials,
When the cement product is cured to produce a cement product, the cement raw material is a cement base material whose main component is cement,
In the method for manufacturing a cement product, which includes the cement surplus material before curing, which occurs in the manufacturing process of the cement product, the reason why the strength of the cement product is lowered by the above-mentioned conventional technique is that the cement surplus material is once manufactured. Since it is supplied above, the hydration reaction gradually progresses in the process until it is mixed with the cementitious material,
When mixed with the cementitious material, CSH-based hydrated solids are produced in the cement residue material, resulting in insufficient consolidation by pressing. Therefore, by suppressing the progress of the hydration reaction of the cement surplus material, based on the speculation that it is possible to suppress the decrease in strength of the cement product, the aqueous solution of oxycarboxylic acid causes the progress of the hydration reaction of the cement surplus material. It was made based on a new finding that it has a delaying effect, and the characteristic means of the present invention for achieving the above-mentioned object is the cement residual material, gluconic acid, oxycarboxylic acid such as glucoheptonic acid, and, It is to adjust the cement raw material by mixing with the cement material in a state of supplying water to form a slurry, and the function and effect thereof are as follows.

[0005]

In other words, the hydroxy group of the oxycarboxylic acid captures calcium ions in the cement, forms a protective film, and delays the hydration reaction. Therefore, in order to suppress the generation of CSH-based hydrated solid matter in the cement, it is considered that the progress of the hydration reaction of the cement surplus material is suppressed. At this time, if the hydration reaction of the cement residual material is simply suppressed, the hydration reaction of the cement raw material itself may be suppressed, but the protective film by the carboxyl group of the oxycarboxylic acid is a temporary one. Therefore, it is considered that when the cementitious material is supplied, the protective film is gradually eliminated, and the hydration reaction itself of the cement raw material is hardly suppressed. As a result, the cement surplus material is slurried by supplying oxycarboxylic acids such as gluconic acid and glucoheptonic acid, and water (hereinafter referred to as a reclaimed slurry), simply adding water to the cement surplus material. Since it can be mixed with the cementitious material in a state in which the hydration reaction has not progressed as much as the just-regenerated slurry, when the cement raw material is finally hardened, it tends to have high strength.

[0006]

[Effects of the Invention] Therefore, it becomes possible to maintain the strength of the cement product high while efficiently regenerating the cement surplus material, and to provide the cement product with high strength, while saving the resources of the cement raw material. In addition, the cost of cement raw materials can be saved, and the cost of cement products can be reduced. The regenerated slurry can have a fluidity similar to that of the cementitious material and can be easily mixed, so that the cement raw material can be easily adjusted.

[0007]

EXAMPLE FIG. 1 shows a production apparatus for producing a cement roofing sheet material, and an example of the present invention will be described with reference to the drawings.

As shown in FIG. 1, an apparatus for manufacturing a cement roofing sheet material comprises an adjusting apparatus A for adjusting a cement raw material 1 in the form of a hydraulic slurry containing reinforcing fibers, and a supply of the adjusted cement raw material 1. Receiving the cement raw material 1
Storage part B1 for storing the above, a supply port B2 for discharging the cement raw material 1 in the storage part B1, and a supply port B2
A cement raw material supply device B having a gate B3 for controlling the opening thickness of the
1, a first conveying device C for receiving the cement raw material 1 flowed out from the supply port B2 and forming it into a strip 2
And a winding device D for winding and stacking the strips 2 on the conveyor belt C1.
1, E2 and a spreading device (not shown) are provided, and a cutting and deploying device E that cuts the strip-shaped body 2 laminated on the winding device D into a plate-like body 3 into a predetermined size is provided. 3 is provided with a second transfer device G that is subjected to various processes such as pressurization, firing, painting, and is transferred to the forming portion F formed on the cement roof plate material.

The adjusting device A is provided so as to be able to supply to the storage portion B1 of the supplying device B while kneading the cement raw material 1 in the form of hydraulic slurry containing reinforcing fibers, and the supplying device B is A storage section B1 for receiving the adjusted cement raw material 1 and storing the cement raw material 1;
It comprises a supply port B2 for discharging the cement raw material 1 in the storage part B1 and a gate B3 for regulating the opening thickness of the supply port B2. As a result, the cement raw material 1 is quantitatively supplied onto the first transport device C and is formed into the strip 2. The first transfer device C is provided with a conveyor belt C1 made of a non-woven fabric, and is provided with a suction device C2 for sucking and removing water from the belt-shaped body 2 via the conveyor belt C1. As a result, the strip 2 is dehydrated and formed into a strip having a relatively stable shape. The winding device D has a cylindrical net cylinder D1.
And includes the mesh cylinder D through the mesh cylinder D1.
A suction device D2 for sucking and removing water from the strip 2 wound around 1 is provided. As a result, the strip plate body 2 supplied from the first transfer device C has the mesh cylinder body D.
The film is wound up into 1 and laminated in multiple layers, and is then dehydrated and molded. The cutting and deploying device E is a series of cutting devices E for forming the strip-shaped body 2 wound around the mesh cylinder D1 into a plate-shaped body.
1, E2 and a developing device (not shown), whereby the band-shaped body 2 is developed into a flat plate shape and molded into a plate-like body 3 cut into a substantially predetermined shape. Further, the plate-like body 3 is pressurized at a high pressure of 20 to 30 MPa, 150 to
It is conveyed by the second conveying device G to the forming section F where the plate-like body 3 is formed into a cement roofing sheet material by performing various processes such as autoclave curing at 180 ° C. for 8 to 20 hours, waterproofing, and painting such as coloring. To be done. At this time, the cut chips and defective products generated from the supply device B to the cutting and developing device E are supplied to the cement material regeneration line H as the cement residual material 4.

The regeneration line H is provided with a kneading device H1 for adding water and gluconic acid (an example of oxycarboxylic acid) to the cement residual material 4 to form a recycled slurry 5, and the cement residual material 4 is The regenerating and conveying device H2 conveys the kneading device H1.
The regenerated slurry 5 is preferably a slurry having a solid content of about 25%, and the gluconic acid a is 2% of the regenerated slurry.
It has been found that it is preferable to set the amount to about a certain level, and the regenerated slurry 5 kneaded by the kneading device H1 is less likely to undergo a hydration reaction and is easily regenerated and used.

The cement raw material 1 is obtained by mixing the amount of cement material 6 composed of cement, pulp fiber, and silica with the regenerated slurry 5 supplied through the regeneration line H, and kneaded uniformly in the adjusting device A. After that, it is supplied to the supply device B.

[Experimental Example] An example in which the strength of the cement roofing sheet formed by the use of the recycled slurry 5 is tested will be described.

<1> Cement roof plate material produced by using cement raw material 1 not containing recycled slurry 5 <2> Solid content 2 without addition of oxycarboxylic acid
After retaining 5% regenerated slurry 5 at 40 ° C. for 5 hours, 25
% Roofing material made of cement produced by using the cement raw material 1 mixed in a ratio of 3% <3> Regenerated slurry 5 having a solid content of 25% added with 2% gluconic acid as an oxycarboxylic acid at 40 ° C. After the retention of time, the roof material made of cement produced using the cement raw material 1 mixed at a ratio of 25% <4> 2 glucoheptonic acids as oxycarboxylic acid
% Regenerated slurry 5 having a solid content of 25% is added at 40 ° C.
Cement roofing sheet material produced by using the cement raw material 1 mixed in a ratio of 25% after staying at room temperature for 5 hours

The above-mentioned four types of cement roof plate materials are manufactured,
Each cement roofing sheet material was compared. The strength was expressed as a relative value with 100 of <1>. As a result, the results are shown in Table 1.

[0015]

[Table 1]

[0016] From Table 1, the cement roofing material made of the cement raw material 1 using the recycled slurry 5 to which no oxycarboxylic acid is added has a greatly reduced strength, and in order to maintain high strength, the amount of the recycled slurry used. However, the strength of the cement roofing board made of the cement raw material 1 using the regenerated slurry 5 to which oxycarboxylic acid is added does not decrease so much that the regenerated slurry 5 is used. It was found that sufficient strength can be obtained even when about 25% is mixed and used. The strength of the cement roof plate material produced by using the cement raw material 1 in which only the oxycarboxylic acid was added instead of the regenerated slurry 5 was the same as that of <1>.

Another embodiment will be described below. The cement product may be a roof material made of cement, a wall material or the like, and these are collectively referred to as a cement product. Further, those manufacturing processes may be those corresponding to various cement products. The oxycarboxylic acid may be gluconic acid, glucoheptonic acid, or the like, and various ones can be used. Also, cement as the cement material amount 6,
Various materials such as cement, silica alone, cement, asbestos, and silica can be used in place of pulp fiber and silica, and the mixing ratio can be variously changed. With respect to the recycled slurry 5, it is sufficient to adjust the ratio of mixing with the cement raw material while adjusting the solid component amount.
The aqueous solution of oxycarboxylic acid may be added, that is, it may be in the form of a slurry so as to facilitate mixing with the amount of the cement raw material. Also, regarding the kneading conditions, means of various bases can be used. The shorter the residence time of the regenerated slurry in the regenerating line H, the more preferable.
When the residence time is short, the strength of the manufactured cement roofing sheet material can be sufficiently suppressed even if the amount of oxycarboxylic acid added is reduced (for example, if the residence time is 2 to 3 hours, gluconic acid 1 % Addition is sufficient).

It should be noted that reference numerals are added to the claims for convenience of comparison with the drawings, but the present invention is not limited to the configurations of the accompanying drawings by the entry.

[Brief description of drawings]

FIG. 1 is a process diagram showing a method for manufacturing a cement product.

[Explanation of symbols]

 1 Cement raw material 4 Cement surplus material 6 Cement base material

Claims (2)

[Claims] 1. A process for producing a cement product, wherein the cement raw material (1) is a cement raw material (6) mainly composed of cement, and a cement product is manufactured by molding and hardening the cement raw material (1). A method for manufacturing a cement product, which comprises the cement residual material (4) before curing generated in 1., wherein the cement residual material (4) is slurried by supplying oxycarboxylic acid and water, A method for producing a cement product, which comprises mixing the cement raw material (6) to prepare a cement raw material (1). 2. The oxycarboxylic acid is gluconic acid,
The method for producing a cement product according to claim 1, wherein the cement product is at least one selected from glucoheptonic acid.