KR19990014544A - Manufacturing method of building materials using sludge from fluoric acid wastewater - Google Patents

Abstract

The present invention relates to a method for manufacturing dry materials using sludge of fluoric acid wastewater, and more particularly, to a method for manufacturing building materials by stabilizing by-product sludge after treating wastewater containing fluoric acid. It relates to a method and a building material produced in this way. The building materials produced according to the present invention are characterized by low absorption rate and shrinkage rate, high compressive strength, sintering can be performed immediately without drying, and low sintering temperature. Therefore, the waste treatment cost can be reduced by recycling the sludge of the fluoric acid wastewater, so that economical and environmental pollution can be reduced, and construction materials having excellent physical properties can be manufactured.

Description

Manufacturing method of building materials using sludge from fluoric acid wastewater

The present invention relates to a method for manufacturing dry materials using sludge of fluoric acid wastewater, and more particularly, to a method for manufacturing building materials by stabilizing by-product sludge after treating wastewater containing fluoric acid. It relates to a method and a building material produced in this way, for example brick or tile.

Wastewater discharged from an electron tube factory, a semiconductor factory, a steel factory, a glass factory, a fertilizer factory or a light bulb factory contains a large amount of fluoric acid. By treating such wastewater, the content of fluoric acid is lowered to less than or equal to 15 ppm, the legal limit. For this purpose, calcined lime, aluminum chloride, aluminum sulfate, iron chloride, iron sulfate, hydrochloric acid, or organic flocculant is usually used.

In this way, the sludge containing fluoric acid which is a by-product of the treatment of fluoric acid wastewater is produced by precipitation and flocculation by the wastewater treatment agent. These sludges are reduced in weight when heated to a high temperature, and when manufactured using them, it is virtually impossible to recycle them as civil and building construction materials because they are thermochemically unstable, such as cracking of construction materials. In addition, the sludge contains a large amount of calcium, it is virtually impossible to use as a building material without stabilization.

Therefore, at present, the sludge produced by treating the fluoric acid wastewater is treated in the form of a waste and is landfilled. The landfilled sludge is redissolved and soaked into the soil, becoming a secondary source of pollution not only soil but also rivers and seas. In addition, the treatment of such sludge involves enormous cost, which causes a rise in manufacturing cost. Therefore, there is a need to recycle sludge.

As described above, the chemical composition of the sludge measured by using an atomic absorption spectrometer is a representative component of the sludge produced by the treatment of wastewater discharged from an electron tube factory, a semiconductor factory, a steel factory, a glass factory, a fertilizer factory, and a light bulb factory. The component contents and their burn loss are shown in Table 1 below.

Chemical Composition and Burning Loss of Fluoric Acid Wastewater Sludge ingredient Content (wt%) ingredient Content or weight loss ¹⁾ (wt%) Si 1.59 K 0.09 Al 2.09 Na 0.89 Fe 0.85 moisture 20.20 Ca 28.4 Organic matter 0.11 Mg 0.51 Burning loss ²⁾ 30.5 1) Burning loss 2) 900 ℃, 2 hours

In Table 1, Si, Ca, Mg, K, Na and Al are components dissolved from glass, and Al, Ca, Fe and organics are components originating from precipitants and flocculants added for treating fluoric acid wastewater. In the form of a compound that can be produced from such sludge, in view of the conventional wastewater treatment process, CaF ₂ , Al (OH) ₃ , Fe (OH) ₃ , Na ₂ SiF ₆ , K ₂ SiF ₆ , MgF ₂ , Mg (OH) ₂ , Ca (OH) ₂ , and the like, which are converted into the form of the most stable compound when heated to a high temperature.

Such sludge is subjected to chemical and physical reactions by adding a precipitant such as slaked lime, a coagulant such as polyaluminum chloride, iron chloride, a precipitation agent such as polyacrylamide, etc. to the wastewater containing fluoric acid. The sludge produced is fine, having a particle diameter of about 400 mm 3 or less, and contains a large amount of water, hydroxide, organic matter, and the like. Therefore, when they are heated to a high temperature of about 900 ℃ or more, as can be seen from the burning loss in Table 1, too much shrinkage, cracking, bending, etc. occur in the molded body, so such sludge alone should not be used for civil and building construction materials. It is virtually impossible to manufacture the back.

Therefore, in order to recycle such sludge, many researchers have made a lot of efforts to stabilize the sludge, and thus product development, but have not yet achieved satisfactory results.

In order to solve these problems, the present inventors have intensively researched, and as a result, by calcining sludge of wastewater containing fluoric acid to physically stabilize or thermochemically stabilizing by adding a stabilizer to the sludge, Good absorption rate, shrinkage rate and compressive strength, low sintering temperature can reduce the manufacturing cost of the product, can reduce the environmental pollution, the manufacturing method of the construction materials using sludge of fluoric acid wastewater, and the construction materials manufactured in this way, For example, to provide a brick or tile.

Accordingly, it is an object of the present invention to provide a method for manufacturing civil and building construction materials having high absorption and shrinkage rates and high compressive strength by stabilizing by-product sludge after treating wastewater containing fluoric acid and a building material manufactured as described above. .

Another object of the present invention is to calcinate and stabilize the fluoric acid wastewater sludge, to pulverize the stabilized calcined product, to form the calcined powder by adding the sludge and the pigment as a binder and to sinter without drying the molding. It is to provide a method for producing a dry material using the sludge of fluoric acid wastewater comprising the step of making and a dry material prepared as described above.

It is another object of the present invention to dry the fluoric acid wastewater sludge, to pulverize the dry matter, to add stabilizers and pigments to the dried powder, to form the resulting mixture and to sinter without drying the molding. It is to provide a method for producing a dry material using the sludge of fluoric acid wastewater comprising the step and a dry material prepared in this way.

The above and other objects, features and advantages of the present invention will be more clearly understood by the following detailed description of the invention.

1 is an X-ray diffraction diagram of fluoric acid wastewater sludge used in the present invention.

2 is an X-ray diffractogram of a fluoric acid wastewater sludge calcined calcined at about 900 ° C. for 2 hours.

Hereinafter, the present invention will be described in more detail.

To recycle sludge from fluoric acid wastewater as civil and building construction materials such as bricks and tiles, the following four conditions must normally be met:

1) When the sludge is formed and then sintered at a high temperature of over 1000 ℃, the molded product should not be deformed or cracked.

2) The manufactured building materials should have low absorption rate and shrinkage rate and high compressive strength.

3) Manufactured building materials should have usable color as building materials.

4) The manufactured building materials should have good weather resistance.

The present invention is a method of manufacturing a building material using the sludge of the fluoric acid wastewater according to the present invention, which meets all of the above conditions, for example, bricks or tiles, etc. It is roughly divided into the method of stabilization by the method and the method of stabilizing by adding a stabilizer to a sludge.

First, the method of manufacturing a building material by baking and stabilizing a sludge is as follows.

The fluoric acid wastewater sludge is calcined in a heating furnace for a certain time, for example 1 to 2 hours, to stabilize the sludge, and the calcined calcined material is ground to a size of about 40 mesh or less, and then calcined to a ground powder as a binder. After the sludge is added, it is molded into a dry material form in accordance with Korean Industrial Standard (KS L 4201-1994), and then the molded product is sintered without drying to prepare a dry material. In addition, in addition to stabilizing the sludge in this manner, a stabilizer may be further used.

Next, a method for producing a building material by adding a stabilizer to the sludge to stabilize the sludge is as follows.

The sludge is dried at about 100 ° C. to dry the dried product to a size of about 40 mesh or less, stabilized by adding a stabilizer to the ground powder, and the stabilized mixture is constructed in accordance with Korean Industrial Standards (KS L 4201-1994). After molding to form, the molded product is sintered without drying to prepare a dry material.

In such a manufacturing process according to the present invention, it is also possible to manufacture a building material of various colors using a pigment as needed.

The furnace is preferably an electric furnace using electricity in the laboratory, but in the industrial field, a furnace using oil or gas may be used.

In the method according to the present invention, the firing temperature is preferably 800 ° C. to 950 ° C., and if the firing temperature is less than 800 ° C., the weight loss change of the slurry is not completed, so that shrinkage occurs when the molded product is sintered at a high temperature. It is not possible to stabilize due to bending and the like, and if it exceeds 950 ° C, the fuel cost increases without any significant change in physical properties, making it uneconomical. In addition, the amount of sludge that is not calcined is preferably 10 to 30% by weight, and if the amount is less than 10% by weight, the shrinkage rate is small but a plasticizer should be added. There are disadvantages such as bending phenomenon. In addition, the sintering temperature is preferably 1000 ℃ to 1200 ℃, if the temperature exceeds 1200 ℃ bending phenomenon occurs, if less than 1000 ℃ there is a disadvantage that the sintering reaction does not occur and the physical properties are lowered.

Stabilizers that can be used in the present invention are suitable such as clay, feldspar, red earth, feldspar, fly ash, silica, magnesia, alumina and the like. The amount of stabilizer added is preferably 10% by weight to 30% by weight, and if the amount is less than 10% by weight, cracking and bending may occur, and thus stabilization may not be achieved. It is not economical because of

According to the present invention, since the sludge is calcined by the method according to the present invention, it is possible to decompose and remove organic matter, water hydroxide, and the like in the sludge which causes the loss of burning, so that cracking and bending occurring at high temperatures do not occur. . In addition, the calcined product calcined at about 900 ° C is composed of components that can be used as construction materials for civil engineering and construction, it can be produced as a dry material without adding any other ore, and if necessary, a small amount of clay mineral is added. It is possible to improve the quality of building materials.

On the other hand, the brick is a main component constituting the CaF ₂ , Al ₂ O ₃ , SiO ₂ , CaO, BaO, Na ₂ O, K ₂ O, Fe ₂ O ₃ and the like because it is pale pink, the building material according to the invention In order to use as a brick, it is necessary to mix and shape a pigment with dried powder. The pigment that is commercially available can be obtained by spraying the surface of bricks in the form of glaze and coloring the surface to obtain a beautiful brick. However, since the price is expensive, it is not profitable to use for cheap bricks. There is almost no.

In consideration of this point, inexpensive building materials such as bricks according to the present invention can be used as a by-product pigment from the waste, for example, fly ash (black) discharged from the iron oxide (red) for the chemical plant, thermal power plant (black) And divalent metal salts can be used.

In the present invention, when 1 to 20% by weight of iron oxide is added to the brick and heated to 1000 ° C. or more, the color is sequentially changed from pink to red. In addition, when the brick containing iron oxide is sprayed with Mn salt, Zn salt, Ni salt, Co salt, Ba salt, Cr salt and the like on the surface, it is changed to black. This is because the metal salt reacts with Fe ³⁺ contained in the brick to turn into a black oxide such as MFe ₂ O ₄ . At this time, if the concentration of the metal salt to be sprayed is adjusted, the intensity of black can be adjusted.

In addition, when a metal salt in which Mn and Zn are mixed in an appropriate ratio is used, a surface having magnetism can be obtained. When the metal salt is Ba salt, a surface having stronger magnetism can be obtained. In addition, when glazes and pigments used in existing tile factories are sprayed on the surface of the building material and fired, a beautiful appearance having a color such as red, green, and yellow can be obtained. That is, it is also possible to produce a brick having a practical color according to the type and amount of additives.

In addition, according to the present invention, since the particles of the wastewater sludge is fine, the sintering process may be performed immediately without undergoing a drying process after molding. Therefore, the manufacturing process of the product can be simplified, and the manufacturing cost can be greatly reduced.

In the present invention, the firing and sintering can be performed simultaneously in the same furnace by putting together the sludge to be fired and the sintered stone to be sintered in the sintering furnace without having to make a separate firing furnace for stabilizing the wastewater sludge. In other words, if the brick to be sintered is placed in the upper part of the high temperature sintering furnace and the sludge to be baked in the lower part of the low temperature sintering furnace, firing and sintering occur simultaneously, thereby reducing the manufacturing cost of the product. There is.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples.

Example 1

Stabilization confirmation test of sludge

The sludge of the fluoric acid wastewater and the crystalline phase of the fluoric acid wastewater sludge calcined at about 900 ° C. for 2 hours were investigated through an X-ray diffraction test (X-ray diffractometer D / Max. IIA manufactured by Rigaku), The results are shown in FIGS. 1 and 2. As can be seen from these figures, the sludge is in the form of a calcium compound of CaF ₂ , and in FIG. 2, the sharp appearance of X-ray diffraction peaks when the sludge calcined product is heated to about 900 ° C. is a CaF ₂ crystal in the sludge calcined product. It shows that it has grown and converted to a stable form.

In order to confirm this fact, the sludge fired material was quantitatively analyzed using an EDX (Energy Dispersive X-ray Spectrometer, Jeol 5400). As a result, it was confirmed that the sludge fired material was composed of 76.77 wt% Ca, 2.32 wt% Mg, 6.67 wt% Si, 7.73 wt% Al, 3.59 wt% Fe and 2.92 wt% Na.

Therefore, the compound form of the sludge burned at about 900 ° C. through X-ray diffraction test and EDX test is CaF ₂ , which is mostly a thermochemically stable compound, and MgO, Al ₂ O ₃ , Fe ₂ O ₃ , SiO ₂ It was found that such a compound exists as a stable compound.

Example 2

Weight loss test according to firing temperature of sludge

The sludge of the fluoric acid wastewater was put into an electric furnace and calcined at 400 ° C., 500 ° C., 600 ° C., 700 ° C., 800 ° C. and 900 ° C. for 2 hours to prepare a sludge calcined product. The weight loss of the sludge according to the heating temperature of the sludge fired material thus prepared was measured by a thermal analyzer (DAT, TGA (Seiko 5200)), and the results are shown in Table 2 below.

Weight loss test according to the heating temperature of the sludge (% by weight) Heating temperature 400 ℃ 500 ℃ 600 ℃ 700 ℃ 800 ℃ 900 ℃ Weight loss 20 22 25 26 28 30

From the above Tables 1 and 2, decomposition of water and organic matter occurs at a heating temperature of 400 ° C., decomposition of a compound present in precipitate form occurs at a heating temperature of 500 ° C. to 800 ° C., and weight loss of sludge is almost reduced at 900 ° C. It was confirmed that it was completed.

Example 3

Measurement of physical properties of sintered materials according to sintering temperature and sludge addition

Sludge from the fluoric acid wastewater was put into an electric furnace and fired at about 900 ° C. for 2 hours to pulverize the sludge burned to about 40 mesh or less, and 0 wt%, 10 wt%, 20 wt% and 30 as unbindered wastewater sludge. After adding the weight%, it is formed into a brick having a length of 60 mm, a butterfly of 20 mm and a thickness of 15 mm, and sintered at 1000 ° C., 1050 ° C., 1100 ° C., 1150 ° C., and 1200 ° C. for 2 hours without drying. Brick was prepared. In each case, the shrinkage of the sintered product was measured and the results are shown in Table 3 below.

Shrinkage rate of brick according to sintering temperature and sludge addition amount (unit: weight%) Sludge Addition Sintering temperature 1000 ℃ 1050 ℃ 1100 ℃ 1150 ℃ 1200 ℃ 0 wt% 2 2 4 5 5 10 wt% 5 6 6 8 8 20 wt% 7 8 10 10 10 30 wt% 12 13 14 14 14

As can be seen from Table 3, the sintering rate of the bricks after sintering at 1050 ° C. for 2 hours was 6% (10% by weight), 8% (20% by weight) and 13% (30) as the amount of sludge increased. Weight percent), but showed a relatively small value. Therefore, when the wastewater sludge is not added to the sludge calcined product, the shrinkage rate is small, but a plasticizer must be added, so the manufacturing cost of the product is increased, which is not suitable. As mentioned above, it turns out that shrinkage is almost completed.

The sludge of the fluoric acid wastewater was put into an electric furnace and the calcined sludge fired at about 900 ° C. for 2 hours was pulverized to about 40 mesh or less, and 10 wt%, 20 wt%, and 30 wt% of unfired waste water sludge was added as a binder. After that, a length of 210 mm, a butterfly of 100 mm, a thickness of 60 mm was molded into a brick, and sintered at 1000 ° C., 1050 ° C., 1100 ° C., 1150 ° C., and 1200 ° C. for 2 hours to prepare a brick. In each case, the absorption rate and compressive strength of the sintered product were measured by Korean Industrial Standard Test Method (KS L 4201-1994) of clay bricks, and the results are shown in Table 4 below.

Absorption Rate and Compressive Strength of Brick with Sintering Temperature and Sludge Addition Temperature Characteristics Absorption rate (% by weight) Compressive Strength (Kg _f / cm ² ) 10 wt% 20 wt% 13 wt% 10 wt% 20 wt% 30 wt% 1000 ℃ 11 10 9 320 323 345 1050 ℃ 10 9 5 348 348 355 1100 ℃ 7 6 4 355 355 355 1150 ℃ 5 5 4 358 355 355 1200 ℃ 4 4 4 358 356 358

From Table 4, it can be seen that as the sintering temperature is higher, the absorption rate becomes smaller and the compressive strength increases. In addition, as the amount of wastewater sludge added increases, the absorption rate decreases and the compressive strength tends to increase slightly. This tends to be due to the decrease in fire resistance as the amount of wastewater sludge increases and the particles of the sludge melt and stick to each other. This is because the reaction rate is increased. In fact, the bricks added with 30% by weight of the sludge had a bend when sintered at 1000 ° C and 1050 ° C for 2 hours, but the bricks added with 10% by weight and 20% by weight of the sludge were completely bent at 1000 ° C. The phenomenon did not occur. In addition, at a high temperature of 1100 ° C. or higher, all the molded bodies exhibited a bending phenomenon.

In addition, the result of sintering at 1050 ° C. for 2 hours showed that the sample added with 10% by weight of wastewater sludge had 10% water absorption and 348Kg _f / cm2 of compressive strength. The strength was 348Kg _f / cm 2, and when 30% by weight was added, the absorption was 5% and the compressive strength was 355Kg _f / cm 2. This result is because the particles are fused to each other at high temperature due to the wastewater sludge to reduce the pores.Because of this phenomenon, the bricks are bent, it is not suitable to add more than 30% by weight of the wastewater sludge to the fired products. I can see that it is not.

As a result, it was found that the sintering temperature is most preferably 1000 ° C to 1050 ° C, and the addition amount of the unfired wastewater sludge is most preferably 10% to 20% by weight. This result far exceeded the standard of one type of brick (absorption rate of 13 ℃ or less and compressive strength of 210Kg _f / cm2 or more) prescribed by Korean Industrial Standard (KS L 4201-1994) of clay brick.

When the sintering temperature was 1100 ° C or higher, it was found that a part of the molded body melted to cause a bending phenomenon, so that a temperature of 1100 ° C or higher was not suitable. This phenomenon is because the wastewater sludge obtained by the precipitation reaction during the wastewater treatment is confirmed by electron microscopy, and the particles have an advantage that the sintering reaction occurs at a low temperature because the particles are too fine at about 400 Pa or less. Therefore, compared with the conventional method of manufacturing bricks using ore, the physical properties are similar, but the sintering temperature is low, and thus the cost of fuel costs can be reduced.

In addition, 20 wt% of unfired sludge in the test and 10 wt% of clay ore such as feldspar, feldspar, red soil and kaolin were added, and as a result, a bending phenomenon began to be observed in all molded bodies at 1100 ° C. Bricks sintered at 1150 ° C. for 2 hours with the addition of 10% by weight clay ore were sludge but slightly better in absorbance (7%) and compressive strength (364Kg _f / cm 2) than the added bricks.

Example 4

Addition test of stabilizer

After the sludge was dried at 100 ° C. for 2 hours, the dried sludge was 10% by weight, 20% by weight and 30% by weight of feldspar, feldspar, clay, red soil, fly, ash, silica, magnesia, silica sand, waste glass and alumina, respectively. The mixture was uniformly mixed with%, and molded into a molded article having a length of 100 mm, a butterfly of 15 mm, and a thickness of 10 mm. Subsequently, the molded article was sintered at a temperature of 950 ° C. to 1200 ° C. for 2 hours to prepare a brick, and the deformation, shrinkage, and compressive strength of the brick thus prepared were measured.

As a result, the feldspar has a low refractory degree, so that deformation occurs at 1000 ° C. even if 30 wt% is added, and fly ash changes the color of the brick to black, so that use of the feldspar is limited to black. Magnesia and alumina were used to make bricks using 20% by weight, and cracks and bending could not be found even at 1150 ° C or higher, and even when only 10% were used, the physical properties were high, but the raw materials were expensive and not practical. Silica, silica sand, and glass waste are the main component but because of the effect of the SiO ₂ be greater than 1150 ℃ give strength to the brick temperature was the bending phenomenon. In addition, when 10 wt% of feldspar, clay and red soil were added, the bending phenomenon began to occur at 1100 ° C., but this phenomenon did not occur at 1050 ° C., and the brick to which 30% by weight was added was added 20% by weight of brick. As such, the most stable brick was obtained at 1050 ° C.

As a result of experiments by varying the mixing ratio based on the experimental results, the bend phenomenon did not occur even at 1100 ℃ bricks added by mixing 5% by weight of feldspar, 8% by weight of feldspar and 7% by weight of clay. Therefore, after molding as described above in such a composition, after sintering at each temperature for 2 hours to prepare a brick, the results of measuring the water absorption and compressive strength are shown in Table 5.

Temperature Characteristics Absorption rate (% by weight) Compressive strength (Kg _f / ㎠) 1000 ℃ 14 308 1050 ℃ 10 338 1100 ℃ 8 345 1150 ℃ 5 354 1200 ℃ 4 358

Table 5 shows that the higher the sintering temperature, the smaller the water absorption rate and the higher the compressive strength. In addition, a bending phenomenon began to occur at 1150 ° C., which caused a part of the molded body to melt to densify the structure of the brick, resulting in a decrease in water absorption and an increase in compressive strength. However, due to the bending phenomenon, the molded body did not become a uniform shape and thus could not be used as a brick. Therefore, in the method by adding the stabilizer, it was found that the bricks sintered at 1100 ° C. for 2 hours by mixing 5% by weight of feldspar, 8% by weight of feldspar and 7% by weight of clay were mixed. .

Example 5

Weathering Experiment

These samples were tested for the weather resistance of sludge-added bricks prepared by the method of Example 3 and bricks added with 5% by weight of feldspar, 8% by weight of feldspar and 7% by weight of clay prepared by the method of Example 4. After being put in a clave oven and kept at 200 ° C. for 3 hours, 4 hours and 5 hours, the compressive strength was measured and no change in the compressive strength was observed.

After the bricks were put in a refrigerator maintained at minus 30 ° C. and maintained for 3 hours, 4 hours, and 5 hours, the compressive strength was measured at room temperature.

Example 6

Coloring test

Bricks were prepared in the same manner as in Examples 4 and 5, except that 5 wt%, 10 wt%, and 20 wt% of iron oxide were added based on the amount of sludge, and pale when 5 wt% was added. When 10% by weight of red was added, it was found that the most suitable amount of red and iron oxide was 10% by weight. Also, black bricks were prepared in the same manner as in Examples 4 and 5, except that 5 wt%, 10 wt%, 15 wt%, and 20 wt% of fly ash were added based on the amount of sludge. The most practical was when 10% by weight of fly ash was added, and the compressive strength of the brick was lowered by adding more than 15% by weight of fly ash. In addition, when the brick formed by adding 10% by weight of iron oxide is immersed in a divalent metal salt solution and fired, a material such as BaFe ₁₂ O ₁₉ , a ferromagnetic material, is formed on the surface of the black brick so that the surface acts like a magnet. It can be seen that this has the effect of providing a weak magnetic force to the human body when constructing such a brick.

According to the present invention, it is possible to manufacture construction materials for civil engineering and construction using sludge of fluoric acid wastewater, the construction materials prepared according to the present invention can be sintered immediately without absorption and shrinkage rate, high compressive strength and without drying process It is characterized by a low sintering temperature. Thus, by recycling the sludge of fluoric acid wastewater, waste disposal costs can be reduced, thereby reducing economic and environmental pollution. It is possible to manufacture a building material having excellent physical properties.

Claims (13)

Calcining and stabilizing the fluoric acid wastewater sludge; Grinding the stabilized calcined product; Molding by adding 10 to 30% by weight of the sludge and a pigment as a binder to the calcined powder; And sintering the molded article without drying it. The method of claim 1, further comprising the step of adding a stabilizer to the calcined powder. The method for producing a building material using sludge of fluoric acid wastewater, according to claim 1, wherein the firing temperature is 800 ° C to 950 ° C. The method for producing a building material using sludge of fluoric acid wastewater, according to claim 1, wherein the sintering temperature is 1000 ° C to 1200 ° C. The fluoric acid wastewater according to claim 1, wherein the pigment is at least one salt selected from the group consisting of iron oxide, fly ash, Mn salt, Zn salt, Ni salt, Co salt, Ba salt, Sr salt and Cr salt. The manufacturing method of building materials which used sludge. The method of claim 1, wherein the sintering process for firing the sludge by putting the sludge and the molded product together in a sintering furnace or sintering furnace and the sintering process for sintering the molded product are simultaneously performed in the same furnace. Manufacturing method. Drying the fluoric acid wastewater sludge; Grinding the dry matter; Adding 10 to 30 wt% stabilizer and pigment to the dried powder; Shaping the resulting mixture; And sintering the molded article without drying it. 8. The method of claim 7, wherein the sintering temperature is between 1000 ° C and 1200 ° C. 8. The fluoric acid wastewater according to claim 7, wherein the pigment is at least one salt selected from the group consisting of iron oxide, fly ash, Mn salt, Zn salt, Ni salt, Co salt, Ba salt, Sr salt, and Cr salt. The manufacturing method of building materials which used sludge. The building material using sludge of fluoric acid wastewater according to claim 7, wherein a sintering process for sintering the sludge by putting the sludge and the molded product together in the sintering furnace or the sintering furnace is performed at the same time in the same furnace. Method of preparation. 8. The method of claim 7, wherein said stabilizer is feldspar, feldspar, clay, red soil, fly ash, silica, magnesia. A method for producing a building material using sludge of fluoric acid wastewater, characterized in that at least one material selected from the group consisting of silica sand, waste glass and alumina. The building material manufactured by the method of any one of Claims 1-11. The building material according to claim 12, wherein the building material is a brick or a tile.