KR100999782B1 - Fabrication method of high-performance clay bricks and clay floor bricks using broken glass - Google Patents

Abstract

PURPOSE: A manufacturing method of a clay brick or a clay floor brick using waste glass is provided to reduce the manufacturing cost by decreasing the plasticizing temperature using waste glass micro powder. CONSTITUTION: A manufacturing method of a clay brick using waste glass comprises the following steps: producing waste glass micro powder(S110); mixing kaolin, feldspar, clay, and the waste glass micro powder(S120); producing base soil by adding water to the mixture from the previous step(S130); extruding the base soil for molding(S140); drying the molded product(S150); and plasticizing the dried product(S160).

Description

Fabrication method of high-performance clay bricks and clay floor bricks using broken glass}

The present invention can significantly reduce the firing temperature to significantly lower the production cost of clay bricks, as well as to produce clay bricks that satisfy the compressive strength and absorption rate of KS standards. It relates to a method for producing a brick.

Kaolin, clay, and feldspar are used as main raw materials for the manufacture of clay bricks. The clay brick manufacturing process is a clay process in which main raw materials such as kaolin, clay and feldspar are mixed, kneaded and pulverized, stored and aged in the furnace, and the raw material supplied from the furnace is extruded using a refiner while maintaining the vacuum state. Forming process of forming bricks, drying process of drying molded body, loading process of stacking dried clay bricks in plastic trolley constantly, firing process of heating clay bricks in high temperature tunnel kiln, sorting and inspecting fired finished products It consists of a process.

On the other hand, if the waste glass is treated as waste without recycling, it can waste resources and cause land pollution. Thus, there have been attempts to manufacture high-performance bricks using such waste glass, but the non-uniform distribution of waste glass due to incomplete waste glass crushing technology, physical properties of the produced product due to incomplete manufacturing process, for example, compressive strength, absorption rate, etc. There were problems such as the poor quality, the warpage of clay bricks and the sticking of clay bricks due to thermal load during firing, and the deterioration of workability and productivity.

In order to solve the above problems of the prior art, the present inventors add waste glass powder finely pulverized using a satellite mill or a raymond mill to prepare clay bricks, thereby greatly reducing the firing temperature of clay. The present invention was completed by discovering that not only the production cost of bricks can be significantly lowered, but also high-performance clay bricks satisfying the compressive strength and water absorption of KS standards can be successfully manufactured.

Accordingly, it is an object of the present invention to provide a method for producing high performance clay bricks and clay floor bricks, which improves the technical problems caused when using waste glass as a raw material of clay bricks.

In order to achieve the above object, the present invention (i) waste glass fine powder manufacturing step of grinding the waste glass (S110); (ii) mixing powder manufacturing step of mixing kaolin, feldspar, clay and waste glass fine powder (S120); (iii) a clay manufacturing step (S130) for producing clay by adding water to the mixed powder; (iv) a molded article manufacturing step (S140) for extruding the clay; (v) a drying step of drying the molded body (S150); And (vi) provides a high-performance clay brick and clay floor brick manufacturing method using the waste glass, characterized in that it comprises a firing step (S160) for heating the dry matter.

The waste glass fine powder manufacturing step (S110) may crush waste glass for 1 to 5 hours using a satellite mill or a raymond mill. If the pulverization is out of the above time range, the waste glass powder is too large and uneven in a short time, so that at high temperature firing, the waste glass melts on the surface of the product and sticks between the bricks, and the constituent elements of the waste glass are not completely dissolved in the brick. Problem occurs. In addition, when pulverizing for a long time there is a problem that the grinding efficiency is lowered, productivity is lowered.

The mixed powder manufacturing step (S120) may be mixed with kaolin 40 to 65% by weight, feldspar 10 to 15% by weight, clay 20 to 25% by weight and waste glass fine powder 5 to 30% by weight. If the kaolin is less than 40% by weight, out of the content range, there is a problem in that the fire resistance is lowered due to the use of alkali raw materials, that is, waste glass and feldspar, resulting in warpage at the lower end of the loaded product. There is a problem in that the fire resistance is increased, the absorption rate is increased, and the firing temperature is increased, and when the waste glass and the feldspar are less than 5% by weight and 10% by weight, respectively, the effect of the addition of alkali raw materials (improved physical properties and a decrease in the firing temperature) is weak. If the content exceeds 30% by weight and 15% by weight, the fire resistance of the clay is lowered, and the resistance to heat load is reduced, resulting in deformation or sticking of the product.In the case of less than 20% by weight of plastic, plasticity is reduced. There is a problem that the capacity is degraded, and if it exceeds 25% by weight, drying is difficult and small Increasing shrinkage may result in large dimensional deviations and lower productivity.

 The clay production step (S130) may be added to 16 to 20% by weight of water based on 100% by weight of the mixed powder. If the content is less than 16% by weight, the surface of the product may not be smooth and a residual amount may be generated. If the content exceeds 20% by weight, the dimensional deviation may increase and the molded part may be deformed (warped). have.

The molded article manufacturing step (S140) may be put into the mold to apply a pressure of 150 to 250kg _f / ㎠ by pressing or extrusion molding with a vacuum drill. If out of the pressure range is less than 150kg _f / ㎠, there is a problem that the strength of the molded product is reduced, if it exceeds 250kg _f / ㎠ may cause a problem that the molded product is deformed (bending).

The drying step (S150) may be dried for 22 to 32 hours at a temperature of 80 to 120 ℃. If the drying temperature is less than 80 ℃ outside the temperature and time range, the drying rate is lowered, and if it exceeds 120 ℃, there is a problem such as the occurrence of cracks due to high heat, if the drying time is less than 22 hours undried products If this occurs, cracks are generated during firing, and if it exceeds 32 hours, the problem of productivity decrease may be caused.

The firing step (S160) may be heated to a firing temperature at a temperature rising rate of 90 to 110 ℃ / h, and then maintained at the firing temperature for 22 to 30 hours, the furnace can be cooled to room temperature to prepare a fired body. If the temperature increase rate is less than 90 ℃ / h outside the above conditions, the productivity is lowered because the firing rate is slow, if the temperature exceeds 110 ℃ / h, cracks may occur in the dry product having a high residual moisture in the preheating section In this case, when the firing time is less than 22 hours, physical properties such as absorption rate and compressive strength may be lowered, and when the baking time is longer than 30 hours, productivity may be lowered.

According to the manufacturing method of the high performance clay brick and the clay bottom brick of the present invention, a high performance clay brick satisfying the KS standard by using finely crushed waste glass using a satellite mill or a raymond mill and In addition to producing clay floor bricks, the addition of waste glass significantly reduces the firing temperature, greatly reducing the production cost of clay bricks, and contributing to resource conservation and environmental protection by recycling waste glass as a raw material for various building materials. Can be. In addition, by developing a firing technology can solve problems such as bending of clay bricks and sticking phenomenon between clay bricks during firing.

Hereinafter, the present invention will be described in more detail with reference to the following examples. However, the present invention is not limited by these examples.

Example 1 Preparation of Specimen for Basic Research and Evaluation of Its Characteristics

(1) specimen production

Basic research specimens were prepared with the compositions shown in Table 1 below. Fine powder was obtained by grinding waste glass for 2 hours using a satellite mill (Fritsch pulverisette 6).

Kaolin, feldspar, clay, and waste glass powder were placed in an oven at 110 ° C. and dried for 24 hours. The prepared powder was then weighed into the compositions in Table 1 and mixed. In order to improve moldability during specimen preparation, clay was prepared by adding water by 18 wt% of the mixed powder for each composition.

Thus prepared clay was put into a mold having a diameter of 25 mm (small specimen) and 50 mm (medium specimen), and a molded body was prepared by applying a pressure of 200 kg _f / cm 2. The molded body was placed in a dryer and dried at 110 ° C. for 24 hours. The dried specimens were placed in an electric furnace, heated to a firing temperature at a heating rate of 100 ° C./h, heated at this firing temperature for 3 hours, and cooled to room temperature to prepare a fired body.

The firing temperature of the small specimen was 1100 ° C., 1120 ° C., 1140 ° C., or 1160 ° C., and the size of the specimen after firing was approximately 22 mm in diameter and 4 mm in thickness. In addition, the firing temperature of the medium specimen was 1050 ℃, 1100 ℃, 1150 ℃, or 1170 ℃, the size of the specimen after firing was approximately 48mm in diameter, 10mm in thickness.

Psalter Composition (wt%) china clay clay feldspar Waste glass Small specimen A1 65 25 10 0 A2 60 25 10 5 A3 55 25 10 10 A4 45 25 10 20 Medium specimen B1 65 25 10 0 B2 60 25 10 5 B3 55 25 10 10 B4 45 25 10 20

At this time, SEM pictures showing the shape and size of the kaolin, feldspar, and clay powder used are shown in Figure 2 (a to c), respectively. These powders were approximately 0.1-55 mu m in size and had a non-uniform shape. The EDS results of these powders are shown in Figs. 3 (a to c), respectively. Kaolin is composed of elements such as O, Na, Al, Si, Ca, and the content of these elements was 51.18, 2.31, 14.20, 24.35, and 7.96 wt%, respectively. Feldspar, like kaolin, is composed of elements such as O, Na, Al, Si, and Ca, and the content of these elements is 61.13, 3.68, 12.67, 22.20, and 0.32 wt%, respectively. In the case of clay, the contents of constituent elements O, Mg, Al, Si, Ca were 62.45, 0.89, 12.69, 23.85, and 0.12 wt%, respectively.

Moreover, the SEM photograph of the crushed waste glass is shown in FIG. The powder size was approximately 0.5 mm to 2.1 μm. As a result of EDS analysis, this waste glass was composed of elements such as O, Na, Mg, Al, Si and Ca, and the content of constituent elements was 56.2, 0.54, 2.01, 9.10, 29.15 and 3.00 wt%, respectively (FIG. 5). .

6 and 7 show the small and medium specimens for basic research prepared by the amount of waste glass and the firing temperature, respectively. At the same firing temperature, the color of the fired body changed from apricot to chocolate as the content of waste glass increased. In addition, at the same waste glass content, the tendency to become reddish as the firing temperature increased.

(2) water absorption measurement

The absorption rate of the prepared small specimens was measured according to the test method of KS L 4201-2008 standard. The prepared specimens were dried at 110 ± 5 ° C. for 24 hours and then allowed to cool to room temperature and weighed. This weight was taken as the dry weight m ₁ (g). The specimens were then immediately placed in water at 20 ± 5 ° C. for 24 hours. The distance between the top of the specimen and the water surface was 50 to 60 mm. The specimens were removed from the water, quickly wiped the surface moisture with a damp cloth, and weighed immediately. This weight was taken as the weight m ₂ (g) including water. Absorption rate was calculated using the following equation and concluded at the first decimal place.

% Absorption = (m ₂ -m ₁ ) / m ₁ × 100

Table 2 shows the results of measuring the absorption of small specimens, showing that the absorption depends largely on the waste glass content and firing temperature. From these results, it can be seen that the absorption rate of the small specimens is greatly reduced as the waste glass content and firing temperature increase.

The absorption of small specimen A1 without waste glass is in the range of 9.4 to 17.5%, and the absorption of small specimen A4 with 20% waste glass is in the range of 0.3 to 9.8%.

In addition, for small specimen A1 without waste glass, the absorption rate decreased from 17.5% to 9.4% with increasing firing temperature. Other small specimens (A2-A4) containing waste glass showed the same trend as the firing temperature increased.

Psalter Firing temperature (℃) Absorption rate (%) A1 1100 17.5 1120 12.5 1140 10.0 1160 9.4 A2 1100 15.4 1120 12.5 1140 7.7 1160 5.0 A3 1100 14.6 1120 12.2 1140 7.3 1160 2.5 A4 1100 9.8 1120 4.9 1140 1.2 1160 0.3

As the waste glass content increases, the absorption rate is lower because the waste glass contains CaO and MgO, which are alkali earth metal oxides, and Na ₂ O, which is an alkali metal oxide. Judging. During the firing, these oxides exist in the liquid phase to facilitate rearrangement of the solid particles, to accelerate material diffusion through the liquid phase, and to compactly fill the solid particles by capillary force. This microstructure characteristic was to have an excellent compressive strength. Absorption rate of medium specimens had the same dependence on waste glass content and firing temperature as on small specimens (Table 3).

Psalter Firing temperature (℃) Absorption rate (%) B1 1050 16.1 1100 14.5 1150 12.5 1170 11.0 B2 1050 16.4 1100 14.4 1150 10.9 1170 9.7 B3 1050 17.2 1100 15.3 1150 9.2 1170 7.1 B4 1050 17.3 1100 14.8 1150 6.4 1170 2.9

(3) crystal structure analysis

The crystal structure of the basic test specimens prepared using an X-ray diffractometer (Rigaku DMAX 2500) was analyzed.

8 and 9 show XRD results of small specimens fired at 1100 ° C. and 1160 ° C., respectively. The main phases of the prepared specimens were SiO ₂ , Al ₆ Si ₂ O ₁₃ , CaAl ₂ Si ₂ O ₈ , and (Ca, Na) (Si, Al) ₄ O ₈ , and the crystal structures and lattice constants of these phases are shown in Table 4. Indicated. It can be seen that the firing temperature used here does not affect the crystal structure of the specimen.

As the content of the waste glass increases, the peak intensity of the SiO ₂ phase decreases, and the peak intensity of the CaAl ₂ Si ₂ O ₈ and (Ca, Na) (Si, Al) ₄ O ₈ phases increases. In the amount of waste glass of 0% and 5% samples Al ₆ Si ₂ O ₁₃ phase is present and, Al ₆ Si ₂ O ₁₃ phase did not exist in the 20% samples. The XRD results of the medium specimens showed the same trend as the XRD results of the small specimens.

Crystal structure Lattice constant Remarks
(JCPDS file number) SiO ₂ Hexagonal a = 4.913
c = 5.405 46-1045 Al ₆ Si ₂ O ₁₃ Orthorhombic a = 7.454
b = 7.689
c = 2.884 15-0776 CaAl ₂ Si ₂ O ₈ Triclinic a = 8.175
b = 12.870
c = 14.182 41-1486 (Ca, Na) (Si, Al) ₄ O ₈ Triclinic a = 8.181
b = 12.870
c = 7.097 41-1481

(4) microstructure observation

Microstructures such as pores, grains, etc. of specimen fracture surfaces prepared using Scanning Electron Microscope (SEM, Hitachi S4700) were observed, and the elements constituting the fired body using Energy Dispersive X-ray Spectroscopy (EDS). And its content was analyzed.

SEM photographs of small specimens fired at 1120 ° C. and 1160 ° C. electric furnaces are shown in FIGS. 10 and 11, respectively. From these results, it can be seen that the porosity decreases as the content of the waste glass increases. In other words, it can be seen that the added waste glass powder was to obtain a compact fired body.

This is because CaO and MgO, the alkaline earth metal oxides, and Na ₂ O, the alkaline metal oxides, in the waste glass act as fluxes, which greatly improves the sinterability. In addition, it was confirmed that the degree of densification gradually increased as the amount of added waste glass increased. The medium specimens showed the same microstructure characteristics as the small specimens, and SEM photographs of the medium specimens fired at 1050 ° C., 1100 ° C., 1150 ° C., or 1170 ° C. are shown in FIGS. 12 to 15, respectively.

16 and 17 show the results of elementary mapping and secondary electron image (SEI) of small specimens containing 0% and 20% waste glass, respectively. From these, the elements in the waste glass are uniformly distributed in the fired body. Medium specimens showed the same constituent distribution as the small specimens (FIGS. 18 and 19).

(5) Compressive strength measurement

The compressive strength of the prepared small specimens was tested according to ISO6872: 1995 (E) standard at 0.5 mm / min cross head speed using a universal testing machine (Instron Model 3365). In addition, in the case of the prepared medium specimens, the compressive strength was measured using a universal testing machine (blue light precision model 9405-503) according to the test method of KS L 1601-2006 standard. The compressive strength was calculated using the pressurized area and fracture load of the specimen.

Table 5 shows the compressive strength results of small specimens by firing temperature (1100 ° C, 1120 ° C, 1140 ° C, and 1160 ° C) and by content of waste glass (0%, 5%, 10%, and 20%). It can be seen that the compressive strength of the specimen with the waste glass is much greater than that of the specimen without the waste glass.

As mentioned earlier, this is the alkaline earth metal oxides CaO and MgO and the alkali metal oxide Na ₂ O in the waste glass. This is considered to be because the back acts as a flux to greatly improve the sinterability to have a dense microstructure. The compressive strength of 20% waste glass specimens was 252%, 233%, 276%, and 247% at 1100 ° C, 1120 ° C, 1140 ° C, and 1160 ° C firing temperatures, respectively. Notice the greater. Medium specimens exhibited the same compressive strength behavior as small specimens (Table 6).

Psalter Firing temperature (℃) Compressive strength (N / ㎡) A1 1100 9.4 1120 12.0 1140 12.7 1160 14.6 A2 1100 14.0 1120 14.5 1140 14.8 1160 18.0 A3 1100 16.2 1120 18.2 1140 23.0 1160 23.8 A4 1100 23.7 1120 27.9 1140 35.1 1160 36.0

Psalter Firing temperature (℃) Compressive strength (N / ㎡) B1 1100 18.0 1180 42.7 B2 1100 22.3 1180 50.5 B3 1100 22.8 1180 54.1 B4 1100 23.7 1180 63.5

Example 2 Preparation of Specimen for Field Research and Evaluation of Its Characteristics

(1) specimen production

Based on the basic research mentioned above, the field study designed the composition of large specimens (clay bricks) as shown in Table 7. The powder was dried and weighed in the same manner as in the basic study. Water was added to the powder prepared for improving the moldability of the powder, and a clay having a water content of 19% was prepared. The manufactured 2.5 kg of clay was put into a mold of 202 mm (length) x 95 mm (width) x 60 (thickness) mm, and a molded article was produced by applying a pressure of 200 kg _f / cm 2. The state which put clay in the metal mold | die is shown in FIG. The prepared molded product was put into a drying chamber and dried at 110 ° C. for 24 hours. The dried specimens were heated at 1130 ° C., 1150 ° C., or 1170 ° C. for 24 hours, and then cooled to room temperature to prepare clay bricks. The finished product was approximately 192 mm x 91 mm x 57 mm.

Psalter Composition (wt%) china clay Clay Feldspar Waste glass C1 65 25 10 0 C2 55 25 10 10

On the other hand, the shape and size of the clay brick prepared by the content (0% and 10%) and the firing temperature (1130 ℃, 1150 ℃, and 1170 ℃) of the waste glass is shown in Figure 21. The clay brick produced in the present invention was approximately 192 mm x 91 mm x 57 mm. At the same firing temperature, bricks with 10% waste glass had a deeper red color than bricks without waste glass. In addition, in the same waste glass content, the redness decreases with increasing firing temperature.

(2) water absorption measurement

The absorption rate of the manufactured clay bricks was measured according to the test method of KS L 4201-2008.

Table 8 shows the content of waste glass and the absorption rate of clay bricks prepared at different firing temperatures. As with the results of the basic research, it can be seen that the absorption rate decreases with increasing waste glass content and firing temperature. The absorption rate of clay brick C1 without waste glass is in the range of 11.3% to 13.7%. However, the absorption rate of clay brick C2 containing 10% of waste glass is in the range of 6.4% to 9.4%, which shows that it satisfies the KS L 4201-2008 absorption rate standard (less than 10%).

Psalter Firing temperature (℃) Absorption rate (%) KS L 4201-2008 standard
(KS 1 type) C1 1130 13.7 below 10
1150 12.2 1170 11.3 C2 1130 9.4 1150 8.9 1170 6.4

(3) Compressive strength measurement

The compressive strength of the manufactured clay bricks was measured using a compressive strength tester according to the test method of KS L 4201-2008 standard. The compressive strength was calculated using the pressurized area and fracture load of the specimen.

Table 9 shows the compressive strengths of clay bricks prepared by waste glass content and firing temperature. This table shows that at the same firing temperature, the compressive strength of bricks with 10% waste glass added is much greater than that of bricks without waste glass added. It is also shown that the compressive strength increases significantly with increasing firing temperature. It can be seen that brick C2 containing 10% of waste glass satisfies the KS L 4201-2008 compressive strength standard (22.54 N / mm2 or more) at all firing temperatures.

Psalter Firing temperature (℃) Compressive strength (N / ㎡) KS L 4201-2008 standard (KS 1 type) C1 1130 21.0 22.54 N / ㎡ or more
1150 24.3 1170 28.4 C2 1130 25.0 1150 29.5 1170 38.0

1 is a flow chart related to a method of manufacturing a high performance clay brick and a clay bottom brick of the present invention,

Figure 2 is a SEM photograph showing the shape and size of (a) kaolin, (b) feldspar, (c) clay powder,

3 shows EDS results of (a) kaolin, (b) feldspar, (c) clay powder,

4 and 5 are SEM and EDS results of crushed waste glass, respectively.

6 and 7 are photographs of small and medium specimens for basic research prepared by the amount of waste glass and firing temperature,

8 and 9 are XRD results of small specimens fired at 1100 ° C. and 1160 ° C., respectively.

10 and 11 are SEM photographs of small specimens fired in 1120 ° C. and 1160 ° C. electric furnaces, respectively.

12 to 15 are SEM images of medium specimens fired at 1050 ° C., 1100 ° C., 1150 ° C., and 1170 ° C., respectively.

16 and 17 are SEI and element mapping results of the small specimen A1 without added waste glass and the small specimen A4 with 20% added waste glass, respectively.

18 and 19 are SEI and element mapping results of the medium specimen B1 without the addition of waste glass and the medium specimen B3 with the addition of 10% waste glass, respectively.

20 is a photograph showing the state in which the prepared clay is put into a mold of 202 mm (length) ㅧ 95 mm (width) ㅧ 60 (thickness) mm,

Figure 21 is a photograph showing the shape and size of the clay brick prepared by the content of waste glass and the firing temperature.

Claims (8)

(i) a waste glass fine powder manufacturing step of grinding waste glass; (ii) preparing a mixed powder mixture of kaolin, feldspar, clay and waste glass fine powder; (iii) a clay production step of producing clay by adding water to the mixed powder; (iv) forming a molded body by extruding the clay; (v) a drying step of drying the molded body; And (vi) A method for producing a clay brick using waste glass, characterized in that it comprises a firing step of heating the dry matter. The method of claim 1, wherein the fine glass powder manufacturing step is a waste glass to prepare a powder having a size of 0.5mm to 2.1㎛ by grinding for 1 to 5 hours using a satellite mill (raytary mill) or raymond mill (raymond mill) Clay brick manufacturing method using the. The method of claim 1, wherein the mixed powder manufacturing step is clay brick using waste glass mixing 40 to 65% by weight of kaolin, 10 to 15% by weight of feldspar, 20 to 25% by weight of clay and 5 to 30% by weight of waste glass fine powder. Manufacturing method.  The clay brick manufacturing method according to claim 1, wherein the clay manufacturing step uses 16 to 20% by weight of water based on 100% by weight of the mixed powder. The method according to claim 1, wherein the molded article manufacturing step is a clay brick manufacturing method using the waste glass to put the clay in the mold by applying a pressure of 150 to 250 kg _f / ㎠ by pressing or by extrusion molding with a vacuum drill. The method of claim 1, wherein the drying step is a clay brick manufacturing method using the waste glass to dry for 22 to 32 hours at a temperature of 80 to 120 ℃. The method of claim 1, wherein in the firing step, the dried material is heated to a firing temperature at a heating rate of 90 to 110 ° C / h, and then maintained at the firing temperature for 22 to 30 hours, and the furnace is cooled to room temperature to produce a fired body. Clay brick manufacturing method using glass. (i) a waste glass fine powder manufacturing step of grinding waste glass; (ii) preparing a mixed powder mixture of kaolin, feldspar, clay and waste glass fine powder; (iii) a clay production step of producing clay by adding water to the mixed powder; (iv) forming a molded body by extruding the clay; (v) a drying step of drying the molded body; And (vi) A method for producing a clay bottom brick using waste glass, characterized in that it comprises a firing step of heating the dry matter.

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