KR100608287B1 - Fired brick with high content of reclaimed anthracite coal ash and preparation method thereof - Google Patents

Abstract

The present invention replaces 30 ~ 90wt% of the natural raw materials used in the manufacture of calcined bricks with anthracite coal ash and fly ash, thereby reducing the cost and strength characteristics of calcined bricks, as well as recycling the landfill ash and fly ash, and using natural resources. The present invention relates to an anthracite embedded coal ash-containing calcined brick and a method for manufacturing the same, which can achieve protection of the natural environment due to reduction. The main configuration of the present invention is a method for producing the anthracite-coated coal ash-containing calcined brick is a step of preparing anthracite coal ash mix soil by mixing 20 to 80wt% landfill ash, 10-40wt% fly ash, 10-70wt% feldspar; Mixing the blended raw materials by kneading 3 to 4 times in a clay process for aging for 130 to 150 hours, and then molding the blended raw materials by vacuum extrusion; The molded brick is characterized in that the firing is maintained for 1 to 4 hours after the temperature is raised to a temperature range of 1000 ~ 1250 ℃ in a tunnel type kiln.

    Fired brick, anthracite, anthracite landfill coal ash, landfill ash, anthracite coal ash, fly ash, bottom ash, kaolin, vacuum extrusion molding

Description

Fired brick with high content of reclaimed anthracite coal ash and Preparation method etc.

1 is a general manufacturing process diagram of a fired brick.

Figure 2 is a manufacturing process of the anthracite landfill coal ash-containing calcined brick according to the present invention.

3 is an XRD analysis of anthracite landfill coal ash.

Figure 4 is a SEM photograph (1000 times) of the calcined bricks added anthracite coal ash 80wt% (filling material 40%, fly ash 40%).

The present invention relates to the production of fired bricks for building using anthracite landfill coal ash generated from a coal-fired coal-fired power plant, and more specifically, the amount of anthracite landfill coal ash composed of anthracite landfill coal ash, fly ash and feldspar 30 Anthracite landfill coal-fired bricks are manufactured at 1000 to 1250 ° C in a tunnel-type kiln after vacuum extrusion molding in order to prepare a mixture soil of ~ 90wt% and to improve the plasticity deterioration problem of the mixed earth due to anthracite landfill coal ash. It relates to a manufacturing method thereof.

In general, the types of plastic bricks for building can be divided into red clay bricks and aged soil bricks. Red clay, red clay, sand and feldspar having high iron content are used as raw materials for the preparation of red clay bricks, and kaolin and feldspar are used as raw materials for the manufacture of kaolin bricks. In the general manufacturing process of these fired bricks, first, red clay and kaolin, which are the main raw materials, have a high moisture content as a natural resource and are dried in a rotary kiln, and the dried raw soil is introduced into the primary mixing process with sub-materials such as sand and feldspar. do. In the primary blended soil, coarse stones are removed from the separator, and the granulation is made in the first and second grinding processes, and then, the mixed clay is uniformly mixed in the second mixing process. The blended soil is stored in a cellar for maturation, and water is added as needed to form a brick in a vacuum extrusion machine. The molded brick produced by the molding machine is dried in a drying chamber and then fired in a tunnel kiln through a loading process.

The main raw materials of calcined bricks are red clay and kaolin, which are natural resources existing in Korea. Recently, due to the strengthening of environmental policies such as preservation of the global environment and national land, the development of natural resources existing in Korea is suppressed, and such policies are expected to be further strengthened. Therefore, it is increasingly difficult to secure red clay and kaolin, which are the main raw materials of fired brick, and it is urgent to develop materials that can replace these resources. As alternative materials, industrial wastes such as coal ash, waste gypsum, dust and waste foundry sand can be considered. Among them, coal ash is evaluated as a potential substitute because it is similar in composition to natural ore such as red clay and kaolin.

Accordingly, the present applicant proposes a method of manufacturing a fired brick and a flooring material by mixing 30% of coal ash powder, kaolin powder, clay and feldspar in the registered patent 10-0415329, and 30-50% of coal ash in kaolin A method for producing a fired brick which can be fired at low temperature by mixing, feldspar, and clay is proposed. In addition, Patent No. 10-0534055 presented a method for producing a fired brick by mixing coal ash 50 ~ 90%, kaolin, feldspar.

However, the prior patent of the applicant has a problem that the natural resources as described above are depleted because even a small amount of the base materials used in the existing calcined bricks such as kaolin, clay.

On the other hand, coal ash generated during power plant development is roughly classified into bottom ash and fly ash. Most of the ash is recycled due to the development of technology such as refining for recycling. Fly ash containing a lot of is being reclaimed, which is called reclaimed ash. Such landfill ash, that is, landfilled anthracite coal ash contains more than 13% of unburned carbon powder, and when the coal ash is used as a cement admixture, it not only lowers the strength of concrete but also adsorbs concrete additives such as foaming agents, thereby degrading the quality of concrete. And the problem of lowering the thermal expansion strength of concrete. Therefore, the anthracite landfill coal ash is used in part as a fine aggregate for brick, roadbed. When the anthracite-filled coal ash is added to the building bricks for construction, the plasticity of the coal ash mixture is drastically reduced, and vacuum extrusion is impossible in the molding process, and even when the brick is formed by the press method, cracks are generated in the firing process. The problem that the plastic brick is deformed occurs. In addition, due to the problem of excessive content of unburned carbon, it was not possible to manufacture a fired brick by the conventional technology.

Therefore, in order to prepare a mixed soil composed of anthracite coal fly ash, fly ash, and feldspar and improve the plasticity problem of the mixed soil, the plasticity is improved by improving the plasticity process, thereby vacuum extrusion molding a brick having an amount of fly ash of 10 wt% or more. If possible, industrial production of anthracite landfill coal ash-containing calcined bricks will be possible.

The present invention has been made to improve the conventional problems as described above, the object of the present invention is to manufacture a fired brick by replacing 30 ~ 90wt% of an anthracite coal ash and fly ash with natural ash used in the production of fired bricks The present invention provides an anthracite landfill coal ash-containing calcined brick and a method of manufacturing the same, which can reduce landfill ash and fly ash as well as reduce cost and improve strength characteristics, and achieve protection of the natural environment by reducing the use of natural resources.

Another object of the present invention is to use anthracite landfill coal ash and fly ash having excellent fire resistance, and to improve the clay process to solve the problem of plasticity degradation of the mixture, and to reduce the firing time by about five times, anthracite landfill having high compressive strength as a fired brick It is to provide a coal ash-containing calcined brick and a method of manufacturing the same.

Anthracite landfill coal ash-containing calcined brick of the present invention for achieving the above object is 20 to 80wt% landfill ash, 10 to 40wt% fly ash, 10 to 70wt% feldspar, vacuum-extruded, 1000 ~ 1250 ℃ high temperature It is characterized by calcining.

Preferably, the method for producing an anthracite-coal fly ash-containing calcined brick includes the steps of preparing anthracite coal ash by mixing 20 to 80 wt% of landfill ash, 10 to 40 wt% fly ash, and 10 to 70 wt% of feldspar; Mixing the blended raw materials by kneading 3 to 4 times in a clay process for aging for 130 to 150 hours, and then molding the blended raw materials by vacuum extrusion; The molded brick is characterized in that the firing is maintained for 1 to 4 hours after the temperature is raised to a temperature range of 1000 ~ 1250 ℃ in a tunnel type kiln.

Preferably, the inorganic plasticizer selected from pottery stone, sericite, bentonite, vermiculite, and waste clay is further included.

When described in detail based on the accompanying drawings, the present invention for achieving the above technical problem is as follows.

FIG. 2 is a manufacturing process diagram of a general calcined brick using the raw material of the present invention, FIG. 3 is an XRD analysis of anthracite landfilled coal ash, and FIG. 4 is a calcined brick to which anthracite coal ash is added 80 wt% (40 wt% landfill material, 40 wt% fly ash). SEM photo of (1,000 times).

As shown in Fig. 1, the main raw materials of the fired bricks are landfill ash and fly ash, and feldspar is used as an auxiliary raw material. In the case of kaolin fired brick, lower kaolin is used as the main raw material and feldspar is used as the subsidiary material.

On the other hand, an inorganic plasticizer can be added to improve the moldability of the fired brick. At this time, pottery stone, sericite, bentonite, vermiculite, waste clay and the like are used for the inorganic plasticizer.

Table 1 compares the physical characteristics of bituminous coal ash, anthracite landfill coal and feldspar. The anthracite coal ash contains higher Al ₂ O ₃ components than bituminous coal ash. Feldspar can also replace kaolin in existing clay bricks with a similar SiO ₂ content.

Anthracite coal ash Bituminous coal ash feldspar Average particle size (㎛) 20-35 15-20 11-25 SiO ₂ (%) 44-46 61-65 46-50 Al ₂ O ₃ (%) 28-29 18-25 28-32 Fe ₂ O ₃ (%) 4 ~ 5 3.5-7 1.2 ~ 5.0 CaO (%) 0.8 ~ 1.2 4 ~ 7 2.6-14.0 Loss of Ignition (%) 13-25 2 ~ 5 2.5 ~ 11.9 Refractoriness 1300 ℃ 1200 ℃ - Mullite  versus small versus

In addition, the anthracite coal ash is a mullite crystal having excellent high temperature characteristics as shown in the XRD analysis of the anthracite coal ash of FIG. 3, and as a result, bricks to which anthracite coal ash is added have improved fire resistance and may be generated in a high temperature firing process. Serious deformation such as cracking can be suppressed.

On the other hand, in the present invention, the production method of anthracite coal ash mixture soil, plasticity improving method, evaluating whether the vacuum extrusion molding, the method of evaluating the characteristics of the molding and plastic products was performed as follows.

Coal ash is added in an amount of 10 to 90 wt% based on the total mixed soil. Among them, an anthracite landfill is added in an amount of 20 to 80 wt%, fly ash is added in an amount of 10 to 40 wt%, and feldspar is added in an amount of 10 to 70 wt%. It was set as the range. In the case of using the inorganic plasticizer, the amount of feldspar was reduced by adding the inorganic plasticizer in the range of 3 to 5 wt%.

As the inorganic plasticizer, one or two minerals such as pottery stone, sericite, bentonite, vermiculite, and waste clay were used.

The mixture consisting of anthracite landfill coal ash, fly ash, feldspar and plasticizer was homogeneously mixed in a mortar mixer while controlling the moisture content to 18 ± 2% to prepare a compounding soil for vacuum extrusion.

Vacuum extrusion of anthracite landfill coal ash was confirmed by a 350 hp vacuum extrusion machine in the actual brick production process, where the molded bricks were heated to a maximum firing temperature at a heating rate of 100 ° C / hr in a 105 m tunnel kiln. The maximum firing temperature was 1000 to 1250 ° C. The holding time at the highest firing temperature was 30 minutes to 2 hours. The properties of calcined bricks were evaluated by comparison of compressive strength, water absorption and weight.

Even when the amount of anthracite coal ash was added to 90 wt% (landfill 80 wt%, fly ash 10 wt%), a small amount of inorganic plasticizer was added to improve plasticity and vacuum extrusion was possible. When the addition amount of the inorganic plasticizer is insufficient, it is difficult to insert the mixed soil into the vacuum extrusion molding machine, and molding is impossible. When the addition amount of the inorganic plasticizer is excessive, the ejection of the molding brick from the vacuum extrusion molding machine is difficult and molding is impossible.

The molding brick obtained by vacuum extrusion molding was baked using the tunnel type kiln. The maximum firing temperature was heated to a temperature increase rate of 100 ℃ / hr, the highest firing temperature. The simplification of this process enabled energy savings and consequently lowered the manufacturing cost of the fired bricks.

The following describes the present invention in detail with reference to comparative examples and examples.

Comparative Example

Table 1 shows the characteristics of the fired bricks manufactured by vacuum extrusion molding with water supply equivalent to 16 to 18 wt% by weight using a mixed soil of 30 wt% clay, 60 wt% kaolin, and 10 wt% feldspar and firing at 1180 ° C. in a tunnel chamber kiln. 2 is shown.

As shown in Table 1, the compressive strength after firing of the molded brick was 23.5 N / mm 2. The weight of one sheet of the obtained fired bricks (size 190 x 90 x 57 mm) was 1.6 kg.

<Example 1>

Coal ash mixture of 60 wt% coal, 30 wt% kaolin, and 10 wt% feldspar was vacuum-extruded with only 18wt% moisture without adding plasticizer and fired at 1100 ℃ in a tunnel room kiln to produce calcined bricks. Shown in

As shown in Table 2, the calcined brick could be molded with only moisture without the addition of plasticizer, and the compressive strength after firing of the molded brick exhibited 28.5 N / mm 2. The weight of one obtained calcined brick (size 190 x 90 x 57 mm) was 1.35 to 1.45 kg.

<Example 2>

Coal ash mixtures containing 40 wt% of ash, 40 wt% of fly ash, and 20 wt% of feldspar were vacuum-extruded with only 18 wt% of moisture without the addition of plasticizer, and then fired at 1040 ° C in a tunnel room kiln to produce calcined bricks. 2 is shown.

As shown in Table 2, the calcined brick can be molded with only moisture without adding a plasticizer, and the compressive strength after firing of the molded brick exhibited 30.5 N / mm 2. The weight of one sheet of the obtained fired brick (size 190 × 90 × 57 mm) was 1.2 to 1.3 kg.

Comparative Example 1 Example 1 Example 2 Raw material Clay, kaolin, feldspar Fly ash, kaolin, feldspar Landfill, fly ash, feldspar Water supply (per 100 kg of soil) Less than 1kg 8-9kg 5-6kg Compounding Material Aging Time 96 hours 120 to 130 hours 130 to 150 hours Clay process circulation 1 time 2-3 times 3 to 4 times Molding pressure 200 psi 250 psi 230 psi Moisture content 18 ± 1% 18 ± 2% 18 ± 2% Drying time 48 hours 40 hours 36 hours Drying temperature 200 ± 20 ℃ 180 ± 20 ℃ 160 ± 20 ℃ Firing temperature 1,170 ~ 1,190 ℃ 1,100 ℃ 1,040 ℃ Water absorption below 10 9% less than 8% or less Compressive strength (N / ㎡) 21.00-26.00 27.00-30.00 28.00-33.00 Bending strength (N / mm2) 3.00 4.50-5.50 4.50-5.50 importance 2.0 to 2.1 1.7 1.5 Porosity 20 30 30 Weight per piece (kg) 1.6 1.35-1.45 1.2 to 1.3

<Example 3>

In the case of coal ash containing 20 wt% of landfill ash, 20 wt% of fly ash, and 60 wt% of feldspar, vacuum extrusion was possible with only 18 wt% of water without the addition of plasticizer. The molded bricks were fired at 1040 ℃ in the tunnel room kiln, and the compressive strength after firing of the molded bricks showed 28.1 N / mm2 and 7.8% water absorption.

<Example 4>

In the case of coal ash containing 30 wt% of landfill ash, 30 wt% of fly ash, and 40 wt% of feldspar, vacuum extrusion was possible with only 18 wt% of moisture without the addition of plasticizer. The molded bricks were fired at 1040 ℃ in the tunnel room kiln, and the compressive strength after firing of the molded bricks was 31.2 N / mm2 and the water absorption was 7.6%.

Example 5

In the case of coal ash containing 40 wt% of landfill ash, 40 wt% of fly ash, and 20 wt% of feldspar, vacuum extrusion was possible with only 18 wt% of moisture without the addition of plasticizer. The molded bricks were fired at 1040 ℃ in the tunnel room kiln, and the compressive strength after firing of the molded bricks showed 33.0 N / mm2 and 7.2% water absorption.

<Example 6>

In the case of coal ash containing 50 wt% of landfill ash, 30 wt% of fly ash, and 20 wt% of feldspar, vacuum extrusion was possible with only 18 wt% of moisture without the addition of plasticizer. The molded bricks were fired at 1040 ℃ in the tunnel room kiln, and the compressive strength after firing of the molded bricks was 30.8 N / mm 2 and the water absorption was 7.9%.

<Example 7>

In the case of coal ash containing 60 wt% of landfill ash, 20 wt% of fly ash and 20 wt% of feldspar, vacuum extrusion was possible with only 18 wt% of moisture without the addition of plasticizer. The molded bricks were fired at 1040 ℃ in the tunnel room kiln, and the compressive strength after firing of the molded bricks was 28.7 N / mm2 and the water absorption was 8.0%.

<Example 8>

Even in the case of coal ash containing 80 wt% fly ash and 10 wt% feldspar, vacuum extrusion was possible with only 18 wt% of water without the addition of plasticizer. The molded bricks were fired at 1040 ℃ in the tunnel chamber kiln, and the compressive strength after firing of the molded bricks showed 28.5 N / mm 2 and 8.7% water absorption.

division Raw Material Formulation Ratio Compressive strength (N / ㎡) Absorption rate (%) Example 3 Landfill (20%), fly ash (20%), feldspar (60%) 28.1 7.8 Example 4 Landfill (30%), fly ash (30%), feldspar (40%) 31.2 7.6 Example 5 Landfill (40%), fly ash (40%), feldspar (20%) 33.0 7.2 Example 6 Landfill (50%), fly ash (30%), feldspar (20%) 30.8 7.9 Example 7 Landfill (60%), fly ash (20%), feldspar (20%) 28.7 8.0 Example 8 Landfill (80%), fly ash (10%), feldspar (10%) 28.5 8.7

As described above, the building fired brick manufactured by the present invention has an advantage of reducing the firing time by 5 times while replacing up to 90 wt% of coal ash and fly ash.

In addition, the weight of the manufactured fired brick is 1.2 ~ 1.3kg to reduce the weight of about 22wt% of the existing kaolin clay brick 1.6kg has the advantage of achieving a lighter weight of the fired brick.

In addition, the present invention can replace the red clay and kaolin, which are the raw materials of the fired bricks conventionally used, with anthracite coal, which is an industrial waste. It is possible to significantly reduce the manufacturing cost of, and to facilitate the transport and masonry of the fired bricks by reducing the weight of the fired bricks.

In addition, in the manufacturing process of calcined bricks, as the amount of natural minerals is reduced, the process of drying the ore in the rotary kiln can be omitted and the crushing process can be simplified from 2 to 1, thereby lowering the manufacturing cost of calcined bricks. have.

Claims (4)

Anthracite landfill coal ash-containing calcined brick, which is mixed with 20 to 80 wt% of landfill ash, 10 to 40 wt% of fly ash, and 10 to 70 wt% of feldspar, and is vacuum extruded. The anthracite-coated fly ash-containing calcined brick according to claim 1, further comprising any one inorganic plasticizer selected from pottery stone, sericite, bentonite, vermiculite, and waste clay. Preparing anthracite coal ash mixture by mixing 20 to 80 wt% of landfill ash, 10 to 40 wt% fly ash, and 10 to 70 wt% of feldspar; Kneading the blended raw material 3 to 4 times in a clay process to mature 130 to 150 hours, and then molding the blended material by vacuum extrusion into a molding brick; The method of manufacturing anthracite-coated coal ash-containing calcined brick, characterized in that the molded brick is heated and maintained in a tunnel type kiln in a temperature range of 1000 to 1250 ° C. for 1-4 hours. 4. The method for producing anthracite-filled coal ash-containing calcined brick according to claim 3, further comprising any one inorganic plasticizer selected from pottery stone, sericite, bentonite, vermiculite, and waste clay.

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