KR19990014545A - Manufacturing method of artificial gravel and terra cotta tile using sludge of fluoric acid wastewater - Google Patents

Abstract

The present invention relates to a method of manufacturing a building material using sludge of fluoric acid wastewater and a method of manufacturing the same. More particularly, the present invention relates to a method of manufacturing a building material for civil engineering and construction by stabilizing sludge produced after treating wastewater containing fluoric acid And a method for manufacturing the same, for example, artificial gravel used for concrete, color ceramics for use in terra cotta tiles, and terra cotta tiles. The artificial gravel, cola cerabol and terazotral produced according to the present invention have low water absorption, high compressive strength and can be sintered immediately without drying. Therefore, it is possible to reduce waste disposal cost by recycling sludge of fluoric acid wastewater, thereby making it possible to produce artificial gravel, color ceramics and terra cotta tiles having economic properties as well as environmental pollution and having excellent physical properties.

Description

Manufacturing method of artificial gravel and terra cotta tile using sludge of fluoric acid wastewater

The present invention relates to a method of manufacturing a building material using sludge of fluoric acid wastewater and a method of manufacturing the same, and more particularly, to a method of manufacturing a building material for civil engineering and civil engineering by stabilizing sludge produced after treating wastewater containing fluoric acid And to artificial gravel used in place of gravel in concrete composed of such manufactured materials, for example, sand, cement and gravel, and to a callacer ball and terraced tile used for making terrazzo tiles.

Wastewater discharged from electric pipe plant, semiconductor factory, steel factory, glass factory, fertilizer factory and bulb factory contains a large amount of fluoric acid. By thus treating wastewater, the content of fluoric acid is lowered to the statutory limit of 15 ppm or less Aluminum chloride, aluminum sulfate, iron chloride, iron sulfate, hydrochloric acid, organic coagulant and the like are usually used.

As described above, the sludge containing fluoric acid, which is a by-product in the treatment of the fluoric acid wastewater, is formed by precipitation and coagulation by the wastewater treatment agent. These sludges are thermo-chemically unstable due to a decrease in weight when heated to a high temperature and cracking of building materials when the building material is manufactured using the sludge. Therefore, it is practically impossible to recycle the sludge as a building material for civil engineering and construction purposes. Further, since sludge contains a large amount of calcium, it is practically impossible to use it as a building material without stabilizing it. Although the discharge amount of such fluoric acid wastewater sludge is increasing day by day, research on the recycling of sludge has not been satisfactory yet.

Therefore, at present, the sludge as a byproduct after treatment with fluoric acid wastewater is mostly disposed in a waste form. The landfilled sludge is reused and permeated into the soil, becoming a secondary source of contamination not only in soils but also in rivers and oceans. In addition, the treatment of the sludge as described above is very costly and causes a rise in manufacturing cost. Therefore, there is a need to necessarily recycle the sludge.

As described above, the components of the representative sludge, which is a by-product of the treatment of wastewater discharged from an electron pipe factory, a semiconductor factory, a steel factory, a glass factory, a fertilizer factory, and a bulb factory, The component content and the ignition loss thereof are shown in Table 1 below.

Chemical content and ignition 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 Weight loss ²⁾ 30.5 1) Reduction of ignition 2) 900 ℃, 2 hours

In Table 1, Si, Ca, Mg, K, Na and Al are components dissolved from glass, and Al, Ca Fe and organic matter are components originating from precipitants and flocculants added for treating fluoric acid wastewater. In view of the conventional wastewater treatment processes, the compounds that can be formed from the sludge are CaF _2, Al (OH) _3, Fe (OH) _3, Na ₂ SiF ₆ , K ₂ SiF ₆ , MgF ₂ , Mg (OH) ₂ and Ca (OH) ₂ , which change to the most stable compound form when heated at a high temperature.

Such a sludge can be obtained by adding chemical additives such as aluminum chloride, aluminum sulfate, iron chloride and precipitating agent, for example, polyacrylamide as a precipitating agent and flocculant to flocculent containing fluoric acid, for example, The sludge produced is fine and has a particle size of about 400 Å or less and contains a large amount of moisture, hydroxides, and organic matters. Therefore, when they are heated to a high temperature of about 900 ° C or more, as shown by the ignition loss in Table 1, too much shrinkage occurs and cracks and bending phenomena occur in the molded body. In addition, There is a possibility that many pores will occur. Therefore, it is practically impossible to manufacture civil engineering and construction materials by using such sludge alone.

On the other hand, terraced roof tiles are generally made of cement, aggregate, colored gravel, and marble sculptures. In order to give color to these terrazzo tiles, colored gravel is used. However, due to the scarcity of colored gravel, it is now mainly used as a color ceramics.

In general, the color sera ball is prepared by mixing pigments such as feldspar, quartz, and stones that have been finely pulverized with a ball mill or the like, mixing them into spheres of various sizes, drying them, and sintering them at a high temperature of about 1200 ° C .

There are generally two methods for constructing the floor coverings by using the color ceramics for the building interior and exterior materials. The first method is to crush feldspar, tungsten and silica and mix them with inorganic pigments to form spherical particles and then sinter them at high temperatures to produce color ceramics. The mixture is then sprayed directly onto the concrete surface by mixing with resin The second method is to mix the color ceramics with cement and apply it to the floor, then polish the surface through watering work. However, these methods have the potential to shorten the life of the building. Since the wastewater and sludge as a byproduct of polishing the surface flows into the sewer as it is, it is not preferable from the environmental point of view. Due to the increase in the construction labor cost and the extension of the construction period Standard construction costs are rising. Therefore, it is a tendency to use a method of attaching terazo tiles in the West, and Korea is gradually being converted into a method of attaching terazo tiles.

At present, Kalasera Ball is manufactured by crushing ore ore, for example feldspar, tossed or quartz, mixed with inorganic pigments, molded into spheres of various sizes, and then sintered at high temperatures. In this way, And the like. In the case of using ceramics produced by using natural ore in the production of terazo tiles, natural ore is used, which causes a high raw material cost and high fuel cost because of high sintering temperature. Therefore, terrazzo tiles in which natural ores are used in this way can not have an advantage in price competition with other building materials such as polymer resin tiles and ceramic tiles used for applications such as terrazzo tiles.

Therefore, if the fluorous acid wastewater sludge referred to in the introduction of the present invention can be recycled to produce calcerabol and terazotile using them, it can be advantageous in price competition with other construction materials as described above.

However, when such fluorinated wastewater sludge is used, porosity remains in the interior of the color ceramics so that when the terazo tiles are polished to polish them, the pores in the terrazzo tiles are exposed outside, There is a problem that the compressive strength of the terrazzo tile is lowered and the durability is lowered even if the pore is not exposed to the outside.

Thus, many researchers have tried to develop a method of recycling fluorous acid wastewater sludge to produce calcerabol and terazotile, but have not yet achieved satisfactory results.

As a result of diligent research to solve these problems, the inventors of the present invention have found that sludge of wastewater containing fluoric acid is sintered and physically stabilized or thermally stabilized by adding a stabilizer to sludge, The production of the balls or, optionally, the production of the terazo tiles using the thus produced balls can provide an excellent water absorption rate and compressive strength, and the sintering temperature is low, so that the manufacturing cost of the product can be reduced, A method of producing artificial gravel, color ceramol and terazotile using sludge of fluoric acid wastewater, and artificial gravel, color cerabol and terazotile produced in this manner.

Accordingly, it is an object of the present invention to provide a method for producing artificial gravel, color ceramics and terra cotta tiles, which have a low water absorption rate and a high compressive strength, and which stabilize sludge as a byproduct after treating wastewater containing fluoric acid, Artificial gravel, callacer ball and terra cotta tile which are manufactured together.

It is another object of the present invention to provide a method for producing artificial gravel using sludge of fluoric acid wastewater comprising mixing a fluoric acid wastewater sludge with a pigment, molding the mixture into spherical and fale shapes, and sintering without drying the molding Or a method of manufacturing a color ceramics, and to provide artificial gravel and a color ceramol manufactured in this way.

It is another object of the present invention to provide a method for producing a sludge, which comprises mixing a fluorine acid wastewater sludge with a pigment, molding the mixture in spherical and fountain forms, dipping the molding in a coating solution and coating, And a method for producing artificial gravel or color ceramics using the sludge of fluoric acid wastewater comprising the steps of:

Another object of the present invention is to provide a terrazzo tile using the color ceramics manufactured according to the present invention.

These and other objects, features and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic diagram showing a color cerabola colored sterically according to the present invention. Fig.

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

FIG. 3 is an X-ray diffraction chart of a fluoric acid wastewater sludge calcined at about 900 ° C. for 2 hours.

Hereinafter, the present invention will be described more specifically.

The following four conditions must be satisfied in order to recycle the ceramic sludge using sludge of fluoric acid wastewater as concrete and terraced sludge using the sludge of fluoric acid wastewater. The synthetic gravel should be mixed with color sera ball, The explanation about artificial gravel is omitted below, and only the color serabol is explained.

1) When the sludge is sintered at a high temperature after molding in the form of a circle and a pyramid, pores should not be generated inside the formed body.

2) The color cera ball manufactured should have a small absorption rate and a high compressive strength.

3) The color serabol manufactured shall have a beautiful color and good weatherability.

4) The terahertzel produced by using cola cerabol should have high compressive strength and hardness and good gloss.

The present invention is a method for producing a color sera ball, artificial gravel and terra cotta tile using sludge of fluoric acid wastewater according to the present invention which satisfies all the above conditions, A method of stabilizing the sludge by firing, and a method of stabilizing the sludge by adding a stabilizer to the sludge.

First, a method of producing color ceramics by sintering and stabilizing the sludge is as follows.

The sludge is stabilized by mixing pigments in a fluoric acid wastewater sludge having a moisture content of 20% or less and shaping the sludge in a spherical shape and a fale shape and sintering in a heating furnace for a predetermined time, for example 1 to 4 hours, The stabilized sintered product is cut to a certain size to prepare a calceraball. In addition to stabilizing the sludge by sintering, a stabilizer may be further used.

In this way, the color ceramics manufactured by the two methods according to the present invention are mixed with cement, aggregate, etc., molded, cured and polished to produce terazo tiles.

The sintering furnace of the present invention is preferably an electric furnace using electricity as an experimental result, but a furnace or a furnace using gas may be used in an industrial field.

In the method according to the present invention, the sintering temperature is preferably 900 ° C. to 1100 ° C., and when the sintering temperature is less than 900 ° C., the sintering reaction does not occur in the case of a large ceramic sphere, They are not fused to each other and separated.

Examples of the stabilizer that can be used in the present invention include clay, feldspar, red soil, pyrophyllite, fly ash, silica, magnesia, alumina, and waste plaster. The addition amount of the stabilizer is preferably from 5% by weight to 30% by weight. If the addition amount is less than 5% by weight, cracks or bending phenomenon occurs and the pores are not stabilized. If the addition amount exceeds 30% by weight, One is not economical due to the increase in the cost of raw materials to be added.

According to the present invention, the sludge can be sintered by the method according to the present invention to decompose and remove organic substances, moisture, hydroxides, and the like in the sludge, which is a cause of the ignition loss, so that cracks and bending phenomena have. In addition, since the sintered product sintered at about 900 ° C is composed of components usable as artificial gravel and color ceramics for civil engineering and construction, it can be manufactured as artificial gravel and color ceramics without adding another ore And the quality of artificial gravel and color ceramics can be improved by adding a small amount of clay minerals as needed.

In addition, according to the present invention, since the particles of the wastewater sludge are fine, the sintering process can be performed immediately after the drying process. Therefore, the manufacturing process of the product can be simplified, and the manufacturing cost can be greatly reduced.

On the other hand, sludge as a by-product of fluoric acid wastewater contains a lot of calcium salts. Some sludge sintered in the range of 950 ° C to 1000 ° C has a pale yellow color, It changes to orange. The pigments usable in the present invention include iron oxide, fly ash, Mn salts, Zn salts, Ni salts, Co salts, and mixtures thereof. The pigment may be mixed with an inorganic pigment in order to color the color ceramics produced using the wastewater sludge. Ba salts, Sr salts, Cr salts and the like. However, a pigment using sludge discharged from a waste having a low cost is preferable.

Considering this point, pigments as a by-product from waste can be used in the construction material according to the present invention. For example, fly ash (for black) discharged from iron oxide (for red), thermal power plant or the like discharged from a chemical factory, By weight of a metal salt or the like may be added in an amount of 1 to 20% by weight based on the pigment.

At this time, if iron oxide and oxides such as zinc, manganese, barium and nickel are mixed and mixed with sludge in an amount of about 5% by weight, crystals such as MFe ₂ O ₄ are produced and changed to black. Here, when M is Ba, crystals such as BaFe ₁₂ O ₁₉ precipitate and become ferromagnetic. This creates a weak magnetic field that draws the metal, and when terrazzo tiles containing such ingredients are placed on the floor of the building, it can be beneficial to the body because it gives a weak magnetic field to the body during physical contact.

In addition, colors such as blue, pink, and green can be produced by mixing and sintering inorganic pigments that have been used in ceramics factories and the like.

In addition, since color and pattern can not be freely constituted like terra cotta with color serabol, there are many restrictions on the use place. In order to make the terrazzo tiles have a three-dimensional color pattern, sludge may be mixed with inorganic pigments of desired colors, molded into spherical or fired shapes, coated with desired materials on the surface, and sintered to produce color ceramics having three- have. Fig. 1 is a schematic view showing a color cerabola colored three-dimensionally according to the present invention. The colored ceramics produced by the method described above are mixed with cement, molded into terra cotta and polished to produce terazo tiles having three-dimensional hues different in color from the inside and the outside as shown in FIG. For example, when the main component is iron oxide, which is a conventional inorganic pigment, and the inside of the coloraser ball is red. When the formed body is dipped in zinc chloride solution or manganese chloride solution and sintered, crystals such as MFe ₂ O ₄ are generated on the surface, The outside of the ceramus ball turns black. Further, when the inside of the color cerambol is in a color other than red, when the ferrous chloride is dipped in a mixture of zinc chloride, manganese chloride or nickel chloride and then sintered, the outside becomes black. Further, in order to impart red color to the surface, it is preferable to immerse the surface in a ferrous chloride solution and then sinter to obtain a desired three-dimensional color. In addition, the outer color of the color ceramic can be varied by appropriately selecting a metal salt. Ferrous chloride (ferrous sulfate) or ferric chloride (ferric sulfate) can be used as a coating solution for red coloring. Ferrous chloride (ferrous chloride Iron (ferric) or ferric chloride (ferric sulfate) and a mixture of zinc, nickel, manganese, barium, cobalt or magnesium salts.

Mixing ratios of cement and cola ceramics for making terazo tiles and the amount of other additives are known, and the curing temperature and curing time are varied to increase the strength of the terazo tiles.

In addition, in order to make terazo tiles into various forms having three-dimensional patterns such as natural marbles and ceramic tiles only, the choice of color ceramics, the type of cement and the kind of additive are important, Element.

Accordingly, in order to give a three-dimensional pattern, the color ceramic balls prepared as shown in FIG. 1 are mixed with cement at a ratio of about 100 per 100 cm ² , molded into a tile, cured, and then polished with a polishing machine I will.

In this case, white cement is often used as a cement to clarify the color of the ceraser ball, and a suitable pigment and black cement can be mixed to give a lot of natural color. In order to give a natural color, it is possible to make natural color by mixing minute stone.

Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to the following examples.

≪ Example 1 >

Sludge stabilization confirmation test

The crystal phase of the sludge of fluoric acid wastewater and sinter of the fluoric acid wastewater sludge sintered at about 900 ° C for 2 hours was examined through an X-ray diffraction test (Rigaku X-ray D / Max.IIA) The results are shown in Figures 2 and 3. As can be seen from these figures, the sludge shows that CaF ₂ crystals have grown to a stable form.

In order to confirm this fact, the sludge sinter was quantitatively analyzed using EDX (Energy Dispersive X-ray Spectrometer, Jeol No. 5400). As a result, it was confirmed that the sintered sludge consisted of 76.77% by weight of Ca, 2.32% by weight of Mg, 6.67% by weight of Si, 7.73% by weight of Al, 3.59% by weight of Fe and 2.92% by weight of Na.

Therefore, the compound form of the sintered sinter sintered at about 900 ° C. through the X-ray diffraction test and the EDX test is CaF ₂ , which is a thermochemically stable compound and MgO, Al ₂ O ₃ , Fe ₂ O ₃ , SiO ₂ , Na ₂ SiO ₃ , K ₂ SiO _3, and the like.

≪ Example 2 >

Weight loss test according to sintering temperature of sludge

The sludge of fluoric acid wastewater was put into an electric furnace and sintered at 400 ° C, 500 ° C, 600 ° C, 700 ° C, 800 ° C and 900 ° C for 2 hours, respectively, to produce sintered sludge. The weight loss of the sludge according to the heating temperature of the sludge sinter thus produced was measured by a thermal analyzer (DTA, TGA (Seico Co., Ltd., 5200)) and the results are shown in Table 2 below.

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

From the above Tables 1 and 2, the decomposition of water and organic matter occurs at a heating temperature of up to 400 ° C., and decomposition of a compound existing in the form of a precipitate occurs at a heating temperature of 500 ° C. to 800 ° C., It was found that it was completed.

≪ Example 3 >

Stabilization test by sintering

The sludge having a moisture content of about 80% is dried to a moisture content of about 20%, molded into a spherical shape having a size of 2 mm to 20 mm, and dried at 400 to 1200 ° C for 1 to 4 hours Lt; RTI ID = 0.0 > Spherical < / RTI > The color ceramics were cut in each case to investigate whether the pores were sintered or not.

As a result of the test, the ceramics having a size of 5 mm or less were sintered at a temperature of 700 ° C. or less for 1 to 4 hours, but the sintering reaction did not occur to the inside, When the sintering was performed for 2 hours, the sintering reaction did not proceed to the inside. When the sintering was performed for 4 hours, about 80% of the sintering reaction occurred. In addition, when the sintering was performed at 900 ° C for 3 hours, the complete sintering reaction occurred to the interior of the color ceramics, and even if the sintering was performed at 100 ° C for 1 hour, the color ceramics could not be separated due to fusion.

The sintered ceramics were sintered at 700 ° C to 1000 ° C for 3 hours, and no cracks were found. No sintering was found in the sintered ceramics at 900 ° C for 3 hours. The sintering reaction did not occur completely. Also, it can be seen that the sintering of color ceramics having a size of about 20 mm at 1000 ° C for 2 hours or more is most suitable.

As a result, it was found that the most suitable condition for sintering of various sizes of cola ceramics at 1000 ° C was 2 hours. The absorption rate of the cola ceramics prepared at this condition was 0.5 wt% and the compressive strength was 380Kg _f / cm < ² >

Then, in order to confirm the durability of the sintered ceramics at 1000 ° C for 2 hours, the callacer ball was placed in the autoclave reaction vessel and maintained at 400 ° C for 5 hours. The color and the compressive strength As a result, there was no change in the color of colasera ball and the compressive strength was almost constant.

However, when the sintering temperature is higher than 1000 ° C, calcium and a small amount of iron oxide are reacted with each other as a constituent of the color ceramics so that the primary colors yellow and blue are not clearly displayed. This phenomenon did not occur up to 950 ℃, but when the sintering temperature exceeded 1000 ℃, the color of the primary color was not clear, but muddy yellow and blue appeared. Therefore, in order to prevent this phenomenon, a clear color was obtained as a result of holding at 950 ° C. for 4 hours, and the absorptivity and compressive strength were almost the same values as those obtained by sintering at 1000 ° C. for 2 hours.

Also, if the moisture content of the sludge is too high and the rising speed of the sintering temperature is high, rapid evaporation of moisture in the sintering process causes cracking in the ceramic sphere and pores in the interior thereof, resulting in a decrease in the strength of the terazo tile. I could not use it as a tile.

Through repeated experiments, it was found that the moisture content was set to 20% or less, the temperature raising rate to 400 ° C was set to 10 ° C / min, and the holding time at the maximum temperature was important regardless of the temperature raising rate at 400 ° C.

<Example 4>

Addition test of stabilizer

Feldspar, silica, stonite, pyrophyllite, pyrophyllite, waste glass, and fly ash, which are stabilizers, are added to the sludge having a water content of 50% in an amount of 5 to 30% by weight based on the sludge, respectively, And sintered at 700 ° C to 1100 ° C for 1 to 4 hours without being subjected to a drying process to prepare callaceramide. When 5 wt% of each stabilizer was added, the effect of addition was not exhibited. When 10 wt% of each stabilizer was added, sinterability was slightly improved. When 20 wt% to 30 wt% was added, sintering was performed at 900 캜 for 4 hr. The sintering reaction was rather poor.

In addition, complete sintering did not occur when sintering at 1000 ° C for 2 hours, and sintering was completed for 4 hours. The ceramics were not fused to each other even when they were sintered at 1100 ° C for 4 hours. When sintered at 1200 ° C for 1 hour, fusion occurred and no cracks and pores were found at any temperature.

It can also be seen that the sintering time is longer when feldspar, zircon and stover are mixed. From the above results, it can be seen that the fine particles of the sludge react with each other at a low temperature to form a liquid phase, and the sintering reaction is completed. When the mineral is mixed, the sintering temperature is increased due to the obstruction of the liquid phase sintering. Water and decomposition materials are rapidly decomposed, liquid phase sintering occurs, cracks and pores are generated, and the effect of preventing the generation of cracks and pores is suppressed because the mineral slows down the liquid phase sintering speed.

When 5 wt% of waste glass was added to the sludge as a reference, sintering at 800 ° C was rather poor at 950 ° C, and glass tends to be melted to fuse the sludge in excess of 950 ° C. And it was found that this tendency was increased at over. This tendency was also observed when 10 wt% of the waste glass was mixed, and it was found that the sinterability was reduced rather than 20 wt%.

When the fly ash was added in an amount of 10 wt%, the sinterability was slightly reduced and the molded product changed to black in sintering. The addition of 20 wt% showed a tendency that the color of Cera Cerabol changed to darker black than when 10 wt% was added, and the sinterability was further reduced at each temperature.

When pyrophosphate was added, the refractory index was increased. When 20 wt% pyrophyllite was added, it was found that complete sintering reaction was required to be performed at 1100 ° C for 2 hours.

&Lt; Example 5 &gt;

Weatherability experiment

In order to test the weatherability of artificial gravels and color ceramics produced by the methods of Examples 3 and 4, these samples were maintained at 1000 ° C for 2 hours, and then fired artificial gravel and callacer balls were heated in an atmosphere similar to the external temperature &Lt; / RTI &gt; for 2 hours.

The artificial gravels and cola ceramics immersed in water were placed in the freezer of the refrigerator for 5 hours at 30 ° C and then kept at 30 ° C for 5 hours. There was almost no change in strength, and no change was observed by observing the surface of artificial gravel and color ceramics with a magnification of 800 times magnification.

&Lt; Example 6 &gt;

Coloration test

Except that 5 wt%, 10 wt% and 20 wt% of iron oxide were added based on the amount of sludge, and when 5 wt% of sludge was added, 5 wt% When 10% by weight of red was added, red was added, and when 20% by weight was added, darker color ceramics were produced. Also, bricks were prepared in the same manner as in Example 4 except that 5 wt%, 10 wt%, 15 wt%, and 20 wt% of fly ash were added based on the amount of sludge. Fly ash 10 When added at a weight% and sintering at 950 캜, it becomes a weak black. When 20% by weight is added and sintered, black strength is increased. However, since fly ash has a disadvantage of lowering sinterability, it is preferable to add 20% .

&Lt; Example 7 &gt;

A test for three-dimensionally coloring Ceracella ball

First, the sludge was mixed with 10 wt% of iron oxide and formed into a spherical shape or a pyramidal shape. The molded product was dipped in a zinc chloride solution (specific gravity: 1.18) To produce three-dimensional color ceramics.

The thus-prepared color ceramics were mixed with cement, molded into terra cotta and polished, and the color ceramics exhibited a three-dimensional hue different from the inside and the outside as shown in Fig. Similarly, sludge was mixed with 5 wt% of various pigments and molded by the above method, and then immersed and sintered in a mixed solution of ferrous chloride (specific gravity: 1.12) and zinc chloride (specific gravity: 1.18) in a molar ratio of 2: 1 . In this manner, the color of the inner surface of the pigment was the same as that of the pigment used, and the surface was black. As a result of polishing with the terahertzel as described above, it was confirmed that color ceramics having three-dimensional hues were produced.

According to the present invention, sludge of fluoric acid wastewater is commonly used to produce artificial gravel and color ceramics and then used to produce terra cotta tiles for civil and architectural purposes. The artificial gravel and calla sera ball Has low water absorption and high compressive strength and can be sintered immediately without drying. It is also possible to prepare color ceramics having a three-dimensional hue and thus to produce terazo tiles. Therefore, it is possible to reduce waste disposal cost by recycling sludge of fluoric acid wastewater, thereby making it possible to produce artificial gravel, color ceramics and terra cotta tiles having economic properties as well as environmental pollution and having excellent physical properties.

Claims (14)

Mixing the fluoric acid wastewater sludge with the pigment; Molding the mixture into spherical and fale shapes; And sintering the molded article without drying, wherein the sludge of fluoric acid wastewater is used. The process according to claim 1, wherein 5 to 30% by weight of the stabilizer is mixed together when the sludge and the pigment are mixed together. The method according to claim 1, wherein the pigment is at least one selected from the group consisting of iron oxide, flyash, Mn salt, Zn salt, Ni salt, Co salt, Ba salt, Sr salt and Cr salt. Wherein the sludge is sludge. The method according to claim 1, wherein the sintering temperature is 900 ° C to 1100 ° C. The method according to claim 2, wherein the stabilizer is at least one material selected from the group consisting of feldspar, pyroxene, clay, clay, fly ash, silica, magnesia, silica sand, waste glass, alumina, Process for the production of artificial gravel or color ceramics using sludge. Mixing the fluoric acid wastewater sludge with the pigment; Molding the mixture into spherical and fale shapes; Immersing the molding in a coating solution to coat it; And sintering the coated molding without drying the sludge of fluoric acid wastewater. 7. The method according to claim 6, wherein 5 to 30% by weight of stabilizer is mixed together when the sludge and the pigment are mixed. The method according to claim 6, wherein the pigment is at least one selected from the group consisting of iron oxide, flyash, Mn salt, Zn salt, Ni salt, Co salt, Ba salt, Sr salt and Cr salt. Of the sludge of the present invention. The method according to claim 6, wherein the sintering temperature is 900 ° C to 1100 ° C. The method according to claim 6, wherein the stabilizer is at least one material selected from the group consisting of feldspar, pyroxene, clay, clay, fly ash, silica, magnesia, silica sand, waste glass, alumina, Process for the preparation of color ceramics using sludge. 11. A process according to any one of claims 6 to 10, wherein the coating solution is selected from the group consisting of ferrous chloride, ferrous sulfate, ferric chloride, ferric sulfate, and zinc, nickel, manganese, barium, cobalt and magnesium salts Wherein the sludge is a solution of at least one substance selected from the group consisting of water, An artificial gravel produced by the method according to any one of claims 1 to 5. 10. A coloraser ball produced by the method according to any one of claims 1 to 10. A terazo tile in which the color ceramics according to claim 13 are used.