JP3431416B2 - Porous surface amorphous porous ceramics and method for producing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a porous ceramic having an amorphous pore surface, which is useful for the treatment of various wastewater and wastewater such as photographic developing wastewater and organic chlorine compounds, which are currently being treated, and its production. The present invention relates to a method and a method for treating various wastewater and wastewater using the method.

[0002]

2. Description of the Related Art Conventionally, various waste water treatment methods using porous ceramics have been known. For example, JP-A-58-205516 by the present inventors describes a molded product of a mud-like product obtained by kneading a mixture of silica stone-clay with feldspar and alumina powder and sawdust and water. Chemicals made by firing at ~ 1200 ° C,
A tube-type ceramic cartridge filter that is excellent in selective removal of heavy metals and the like is described.

Japanese Patent Publication No. 1-60317 by the present inventors discloses a treatment layer in which a filtration layer composed of a sand or gravel layer is provided at the bottom of a treatment tank, and porous ceramic particles are laminated on the filtration layer. Is provided, and a wastewater treatment device for sewage or the like is described in which diffusers are provided on the upper surface of the treatment layer and the lower surface of the filtration layer.

Japanese Patent Application Laid-Open No. 61-13649
In JP-A-0, a filter medium made of porous ceramic granules, which is filled in a perforated material such as a mesh at a distance, is provided upright at a position transverse to the flow direction of wastewater in an aeration tank. An aeration-type wastewater treatment device is described.

According to Japanese Patent Publication No. 1-42758 by the present inventors, a porous material such as a mesh body is filled with a space at a position transverse to the flow direction of waste water in an aeration tank. An aeration tank formed by standing a filter material made of porous ceramic particles is connected to the aeration tank by a pipe, and a filtration layer made of sand or gravel is provided at the bottom of the aeration tank, and a porous layer is formed on the filtration layer. Providing a treatment layer in which ceramic granules are laminated,
There is described an aeration-type advanced wastewater treatment device comprising a treatment tank in which air diffusers are arranged on the upper surface of the treatment layer and the lower surface of the filtration layer.

Japanese Patent Publication No. 2-1558 discloses that wastewater such as domestic wastewater, industrial wastewater and food processing wastewater is biologically treated in a treatment medium containing porous ceramics and wood chips as main components. The method of processing is described.

Japanese Patent Publication No. 63-66247 by the present inventors
The publication describes a method for treating emulsifying oil-containing wastewater which is used as a filter device by filling a cylindrical body with a mixture of porous ceramics and activated carbon as a filter medium.

Japanese Patent Application Laid-Open No. 60-26158
No. 6 discloses a method of removing metals, metal ions and organic chlorine compounds from drinking water such as tap water, using a filter having an intermediate layer made of a layer of activated carbon between layers of porous ceramics. Have been described.

Further, JP-A-61-2 by the present inventors
In Japanese Patent No. 91473, a method for producing porous ceramics used for treating these wastewater and waste liquid is described as follows. "A porous material is added to a slurry obtained by adding water to clay mineral powder and mixed, dried and fired to form a porous ceramic. In the method for producing, the pore-forming material is subjected to a pretreatment for binding a metal powder or an organometallic bond to the surface of the pores, and firing is performed in air or under a nitrogen atmosphere. Is described.

[0010]

However, the above-mentioned method and the conventionally known porous method for treating various kinds of wastewater and waste liquid, such as waste liquid containing organic chlorine compounds such as tetrachloroethylene and trichloroethane, whose treatment is currently a problem. Even if ceramics were applied, it was not possible to completely remove harmful and pollutants in wastewater and waste liquid.

Further, in the above-mentioned Japanese Patent Laid-Open No. 61-291473, according to the description of the example, the temperature of the dried molded body is increased and the sintered body is fired at about 1200 to 1500 ° C. for 1 hour to produce a porous ceramic. It takes 1200-15
When the temperature is raised in the electric furnace up to 00 ° C for a short time and the firing is performed for about 1 hour, the obtained ceramics become homogeneous throughout, the pore surface is not amorphous, and the compressive strength is In the case of ceramics with large variations and low compressive strength, it is easy to pulverize, and when packed in a column for wastewater / waste liquid treatment, clogging occurs and it is difficult to use for a long time. When used, it was not practical because the performance of removing harmful and polluting components was insufficient and it was difficult to use for a long time.

[0012]

Therefore, the present inventors have
Currently, the treatment of these harmful and pollutant substances in wastewater and waste liquid containing P (phosphorus) and N (nitrogen), organochlorine compounds such as tetrachloroethylene, and heavy metals such as hexavalent chromium and lead has become a problem. The quality of the porous ceramics has been improved by studying one by one to develop practical porous ceramics that can be removed to near zero and fall below the water quality standard of When we overwhelmed the conventional knowledge of how to make porcelain, we created porous ceramics whose surface and pore surface composition were different and the pore surface was amorphous. The present invention has been completed by discovering that ceramics are effective and practical for treating various drainage and waste liquids.

That is, according to the present invention, clay, a pore-forming material and water are mixed, shaped into an appropriate shape and then dried, and the temperature of the dried molded article is adjusted by self-combustion of the pore-forming material in the molded article. After raising the temperature from room temperature to 600 to 800 ° C. over 5 to 15 hours, preferably about 10 hours, the molded product temperature is maintained at 600 to 800 ° C. for 3 to 7 hours, preferably about 5 hours, Then, after raising the temperature to 1200 to 1500 ° C., it is fired at this temperature for 4 to 8 hours, preferably about 6 hours, cooled and then subjected to crusher treatment, and the porous ceramics having an amorphous pore surface and a method for producing the same. It also relates to a method for treating wastewater and waste liquid using the same.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The "clay" used in the present invention has tackiness and plasticity when added with water and has a property of becoming hard when dried, and most of them are composed mainly of silicate minerals. However, it may contain other inorganic components such as calcium, magnesium, sodium, potassium, etc., if necessary.

[0015] a "pore-forming material" used in the present invention, sawdust, wood chips, chaff, wheat straw, wheat bran, bark also derived from (bark) such plants etc., to burn while generating gas by heating viewpoint what Ki out using any one, in particular sawdust, wood chips without sudden gas generation in natural stage, pores surface formed stably structure of the porous ceramic is amorphous as long as From desirable.

As the "water" used in the present invention, tap water is usually used, but seawater can also be used when other clay minerals have a low alkali content. Further, when the other raw material clay or pore-forming material contains water, the water can be used as a substitute.

In the present invention, the "kneading" of the clay, the pore-forming material and the water is carried out by appropriately kneading these three parts in a kneading machine such as a mortar cement mixer until they are uniform, and The mixing ratio of these components may be any ratio as long as the pore surface amorphous porous ceramics of the present invention can be obtained. From the viewpoint of the purpose of adsorbing to the smooth portion, a mixture of clay 2: water 3.2: pore forming material 6.76 (part by weight, the same applies hereinafter) is desirable, but not limited to this. After mixing, the mixture is molded into an appropriate shape such as a brick shape or a disk shape so as to be easily baked.

The "drying" after molding in the present invention is usually carried out by allowing it to stand at room temperature until the water content reaches 40%, but it can also be carried out by ventilation drying using a burner or the like. It is not limited to standing drying.

"Raising the temperature" and "calcining" in the present invention include
Anything can be used as long as it can heat and fire the above-mentioned molded body after drying, such as an electric furnace, a kiln or a kiln made of refractory bricks, but mass production of uniform ceramic products at once. A kiln or kiln is preferable from the viewpoint of being able to do so.

In the present invention, the molded product after firing can be used as it is as a block type or cartridge type filter, but when it is used by packing it in a column or the like, it is usually subjected to a crusher treatment. Is given. Although any type of ordinary crusher such as a roll type can be used for this crusher treatment, in order to reduce the proportion of powdery ceramics unsuitable for use in a column or the like, the present inventors It is preferable to use a roll-type crusher in which the narrowest part of the roll is adjusted to 10 to 30 mm.

Next, the most important "temperature raising" and "firing" steps in producing the porous porous ceramics of the present invention will be described. First, gradually increase the temperature of the molded product after molding from room temperature to 600 to 800.
The temperature is raised to ℃, preferably 800 ℃. By adopting such a gradual temperature raising step, the properties of the ceramics after sintering are kept almost the same as those at the time of manufacturing the molded body, and while forming sufficient continuous pores, it is possible to obtain a sufficient treatment object. It has a reaction part.

On the other hand, a conventional heating method that does not employ this slow heating step, such as an electric furnace as in the case of producing the porous ceramics described in JP-A-61-291473, is used. If a temperature rising method that follows a rapid temperature rising process is adopted, the ceramics after sintering will be brittle even if the bond between the crystal components is insufficient, and at the same time most of the pore surface formed in the ceramics will be covered with crystalline material. The property that the component to be treated has a large resistance when passing through the pores and the component to be treated cannot sufficiently penetrate into the pores.
It has the property that it is contaminated with wastewater and wastewater.
When applied to the removal of harmful components, the removal is insufficient, and a product that can withstand long-term use cannot be obtained.

The time required to raise the temperature from the slow room temperature to 600 to 800 ° C. is usually about 5 to 15 hours, preferably about 10 hours, depending on the size and amount of the molded product. Such heating can be controlled by adjusting the heating and heating of the electric furnace, the kiln, and the kiln, but flammable pore-shaped materials such as sawdust.
One corner of the dried molded body comprising forming material, for example ignited by a burner or the like, is carried out by combustion of combustible pore-forming material itself sawdust or the like in the molded body (self combustion). This method of controlling the product temperature by self-combustion is an epoch-making method first found by the present inventors in preparing porous ceramics. By adopting this method, heavy metals and high BO can be obtained.
It has been confirmed that a more excellent porous ceramic product for treating wastewater / waste liquid such as D waste water, high COD waste water, etc. can be obtained.

In this way, when the temperature of the dried molded product reaches 600 to 800 ° C. over 5 to 15 hours, combustibles such as sawdust in the molded product are incinerated. At this stage, the temperature of 600 to 800 ° C. is kept for 3 to 7 hours by additional heating,
Hold for approximately 5 hours. This step is an indispensable step for producing the porous ceramics of the present invention whose pore surface is amorphous.

By adopting this step, the alkaline component in the clay gradually begins to melt, and as a result, the surface of the open pores of the porous ceramic becomes amorphous, and the strength of the porous ceramic after sintering increases. Without adopting this process, it is possible to remove from 12
If the material is heated all the way from 00 to 1500 ° C., not only the quality of the ceramics after firing will vary, but also the removal performance of harmful and pollutants will be insufficient.

For example, various compressive strengths of various strengths are produced, and those having low compressive strength become powdery in the crusher treatment after firing,
If this powdery ceramics is packed in a column and then subjected to drainage / waste liquid treatment, the fluid resistance is large and clogging occurs immediately, and it cannot be put to practical use at all.

Next, the molded body heated at 600 to 800 ° C. for 3 to 7 hours takes 1200 to 1 over 4 hours.
Raise the temperature to 500 ° C. In the present invention, 1200-
The range of 1500 ° C. and its firing temperature is due to controlling the amounts of silicon dioxide and alkali in the clay to obtain different active surfaces as a result of firing. That is, when the amount of alkali in the clay is relatively large and the sintering is easy, the temperature may be about 1200 ° C. Firing at about 1250 ° C is particularly preferred because it yields a ceramic that can be used.

When the temperature of the molded product reaches 1200 to 1500 ° C., it is fired at this temperature for 4 to 8 hours, preferably about 6 hours. If the firing time at this temperature is about 1 hour as described in JP-A-61-291473, the surface amorphization of the continuous pore forming part is insufficient, and the continuous pore forming part is not formed. Only ceramics, which have the drawback of being easily broken, can be obtained because sufficient sinter strength cannot be obtained.

In the present invention, "the surface of the pores is amorphous" means that the surface of the continuous pores formed inside the ceramic is
It refers to a combination of an amorphous material containing sodium silicate as a main component and a crystalline material (crystalline particles) such as sodium silicate and calcium oxide. The crystalline part (crystalline particles) reacts with the component to be treated in the wastewater, but the amorphous part does not contribute to the reaction.

However, the surface of continuous pores was subjected to a field emission scanning electron microscope S-4200 manufactured by Hitachi, Ltd. under the conditions of accelerating voltages of 10 KV (secondary electron image) and 20 KV (backscattered electron image) and a photographing magnification of 3000 times. In the conventional porous ceramics disclosed in Japanese Patent Laid-Open No. 61-291473, for example, as shown in FIG. Part is covered with crystalline particles 3,
Even if the flow 4 of the component to be treated reaches the ceramic particles and tries to pass through the continuous pores 2, the resistance is large and the component to be treated cannot sufficiently flow into and permeate into the pores 2.
It is almost the surface 1 of the ceramic particles that contributes to the reaction with the component to be treated, whereas in the surface amorphous porous ceramics of the present invention, as shown in FIG. Since the amorphous portion 5 exists, the flow 4 of the component to be treated reaches the ceramic particles and the resistance when passing through the continuous pores 2 is small, and the component to be treated can sufficiently flow into and permeate into the pores 2. Therefore, it is considered that not only the surface 1 of the ceramic particles but also the crystalline particles 3 present in the pores 2 react with the component to be treated, and as a result, an excellent wastewater treatment effect can be achieved.

The type of drainage / waste liquid that can be treated using the porous ceramics of the present invention having an amorphous pore surface is not particularly limited, but the present inventors have been so far. Using porous ceramics with an amorphous pore surface, waste liquid containing organic chlorine such as trichloroethane, pig manure wastewater with high organic nitrogen content, heavy metals such as lead, hexavalent chromium, nickel, mercury, zinc, cadmium, selenium, etc. Waste liquid contained, dairy product manufacturing plant with high water-soluble protein content, wastewater from fish processing plant, slaughterhouse, rivers, lakes and marshes containing P and N, which are difficult to remove, pulp mills Its effects have been confirmed in waste water, waste liquid discharged during photo development, and waste water containing wax and detergent from car wash areas.

The "activated carbon" used in the present invention may be any charcoal, coconut shell, coal char, or any other material produced by sufficiently carbonizing raw materials such as animal bones and blood.
As long as it is a substance made of a porous carbonaceous material having a large specific surface area and adsorption ability, it is not limited to the commercially available substances.

[0033]

The following examples are given to clarify the characteristics of the present invention, but the present invention is not limited to these examples. The parts in the examples represent parts by weight. Example 1 Production of Porous Ceramics with Amorphous Pore Surfaces 2 parts of clay (collected from the Seto region), 3.2 parts of water and 6.76 parts of sawdust were thoroughly kneaded using a kneading machine, and longitudinally And width and height are 250 mm x 130 mm x 110 m, respectively
Molded into a brick of m, until the water content becomes 40%,
It was dried at room temperature for 3 days. The dried brick-shaped molded body was put in a ceramic pot having a volume of 10 m ³ , and one corner was ignited by a burner. After about 10 hours, the sawdust in the molded body was incinerated by self-combustion, and the product temperature reached about 800 ° C. This ashed molded body with a product temperature of about 800 ° C is heated (fired)
Then, the product temperature was kept at about 800 ° C. for about 5 hours.

Next, the molded body was heated for about 4 hours until the temperature reached about 1250 ° C., and was baked at this temperature for about 6 hours. After the molded body after firing was cooled, it was taken out from the kettle.

At this time, the compression strength of the molded product was measured by a compression strength tester manufactured by Shimadzu Corporation to find that it was 6.0.
A high compressive strength range of ˜9.5 Kg / cm ² was obtained. Next, when this product was crushed by a crusher, 20% of the product had a diameter of 10 mm or more, and 6 to 1
30% for 0 mm, 20% for 2 to 6 mm, 2
A powdery material having a size of not more than mm was obtained at a rate of 30%.

The physical properties of the porous ceramics obtained in Example 1 were as follows. Bulk specific gravity 0.36 to 0.40 Porosity 86.7% Specific surface area 23 m ² / g

The composition of the above-mentioned porous ceramics is KE
Energy dispersive X-ray spectrometer SIGMA2 manufactured by VEX
The composition of the whole ceramic was composed of silicon oxide, aluminum oxide, iron oxide, calcium oxide, magnesium oxide, potassium oxide, sodium oxide, etc., when measured with a mold under an acceleration voltage of 15 KV and a measurement time of 100 seconds. The composition of the active part of the pore surface is crystalline such as sodium silicate, calcium silicate, calcium oxide, magnesium oxide, and the composition of the inactive part of the pore surface is sodium silicate, silicon oxide, oxide. It was amorphous such as aluminum, potassium oxide, and sodium oxide.

The porous ceramics of the present invention are
Compared to the composition of the whole ceramic and its outer surface,
The composition of the surface of the pores contains a large amount of silicon-based components, and the surface state of the electron micrograph shows that the porous ceramics of the present invention is a porous ceramic in which the surface of the pores is amorphous.

Comparative Example 1 Production of Porous Ceramics by Conventional Method The same procedure as in Example 1 was carried out except that the following temperature rising / firing step was adopted. That is, the dried brick-shaped molded body prepared in the same manner as in Example 1 was put into an electric furnace, and the temperature of the molded product was 125 in a substantially linear manner.
It heated for 4 hours until it rose to 0 degreeC, and baked at 1250 degreeC for about 1 hour.

The compression strength of the molded product after firing was measured by a compression strength measuring instrument manufactured by Shimadzu Corporation in the same manner as in Example 1, and it was 2.1 to 9.6 Kg / cm ² , which was in the range of compression strength. , And the ratio of low compressive strength was high. Next, when this product was crushed by a crusher and crushed,
%, 6 to 10 mm was 10%, 2 to 6 mm was 20%, and 2 mm or less was 65%, and the proportion of powder was very high compared to Example 1. It was

The physical properties of the porous ceramics obtained in Comparative Example 1 were as follows. Bulk specific gravity 0.4 to 0.52 Porosity 85.6 to 87.1% Specific surface area 18 to 38 m ² / g

The composition of this porous ceramic was measured in the same manner as in Example 1. As a result, there was no great difference in the composition of the whole ceramic, the composition of the active portion on the particle surface and the pore surface, and the composition of the inactive portion on the pore surface. .

Comparing the above various physical properties with those of Example 1, there is no difference in the overall composition or the composition of the outer surface, but from the state of the pore surface by the electron micrograph, the pore surface of the present invention is shown. Unlike porous ceramics, which has an amorphous structure, the surface of the pores is a homogeneous crystalline material consisting mostly of silicon oxide, calcium oxide, etc., with large crystal particles and insufficient bonding between crystal particles. It does not have a structure in which active crystal particles are arranged in an appropriate amount as compared with those in Example 1 (see FIGS. 1 and 2 above).

Example 2 Treatment of Organochlorine-Containing Waste Liquid Using Porous Ceramics of Amorphous Pore Surface of the Present Invention Porous Amorphous Porous Surface with a Diameter of 6-10 mm Obtained in Example 1 Using a 50:50 mixture of ceramics and activated carbon (manufactured by Takeda Pharmaceutical Co., Ltd.), 10 liters of industrial waste liquid containing tetrachloroethylene was treated using the treatment apparatus of FIG. 3 as follows.

As shown in FIG. 3, diameter 26 mm, length 1
In a column 6 having a volume of 03 mm and a volume of 50 ml, the porous ceramics obtained in Example 1 and having an amorphous pore surface 12.5.
A mixture 7 of activated carbon in the same amount as g was filled, and three of these were connected in series, and a linear water velocity of 0.2 mm /
Second, a long-term continuous operation was performed for 14400 minutes (100 days) of water flow under the treatment conditions of contact time of 25 minutes 45 seconds and treated water volume of 6.7 ml / min. The result is shown in FIG.

In FIG. 4, the mark ● represents the concentration of tetrachloroethylene in the waste liquid discharged from the factory, and therefore the concentration varies depending on the sample obtained. In addition, the symbol ■ represents the concentration of tetrachloroethylene after the treatment. As can be seen from FIG. 4, the concentration of tetrachlorethylene in the waste liquid after the treatment using the porous ceramics having an amorphous pore surface of the present invention decreased to 0.01 mg / L, which is a water quality standard in Japan. It was well below 0.1 mg / L.

Further, this tetrachloroethylene concentration is 0.0
It was confirmed that the treatment capacity of 1 mg / L continued until the continuous water passage time of 10680 minutes. From these results, the action of the porous ceramics having an amorphous pore surface of the present invention cannot be explained by mere physical adsorption, and since the growth of microorganisms is not observed in the column, its mechanism is clear. However, it seems that tetrachloroethylene is decomposed by some action.

Comparative Example 2: Treatment of organic chlorine-containing waste liquid using only activated carbon The same as Example 2 except that activated carbon alone was used in place of the mixture of porous ceramics whose pore surface was amorphous in Example 2 and activated carbon. Went to. The result is shown in FIG.
In FIG. 5, the ● symbol represents the concentration of tetrachloroethylene after the treatment with the mixture of the pore surface amorphous porous ceramics and the activated carbon, and the ■ symbol represents the concentration of tetrachlorethylene in the activated carbon alone treatment.

As can be seen from FIG. 5, when only activated carbon was used, the amount of tetrachlorethylene in the waste liquid was
It dropped only to 0.1 mg / L. This value is 10 times the value in the case of using the mixture of porous ceramics whose pore surface is amorphous in Example 2 and activated carbon,
From this, the effectiveness of the porous ceramics of the present invention whose pore surface is amorphous is well understood.

Comparative Example 3 Treatment of Waste Liquid Containing Organochlorine Using Porous Ceramics by Conventional Method The same procedure as in Example 2 was carried out except that the porous ceramics produced in Comparative Example 1 was used. As a result, Comparative Example 1
The treatment with the mixture of the porous ceramics and the activated carbon produced according to the above-mentioned method is almost the same as the treatment with the activated carbon alone in Comparative Example 2 above, and the porous ceramics and the activated carbon of which the pore surface of the present invention is amorphous in the adsorption ability of tetrachloroethylene and its sustainability are the same. Was inferior to the case of using.

[0051]

EFFECTS OF THE INVENTION By using the porous ceramics having an amorphous pore surface according to the present invention, it becomes possible to remove and decompose harmful and pollutants in wastewater and waste liquid, whose treatment is currently a problem. It can be said that it is extremely practical because the removal / decomposition action lasts for a long time.

Further, according to the production method of the present invention, not only the porous ceramics having amorphous pore surfaces can be produced, but also those having a high compressive strength range useful for treating waste water and waste liquid can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic view showing a state of a pore surface of a conventional porous ceramics.

FIG. 2 is a schematic diagram showing the state of the pore surface of the surface amorphous porous ceramics of the present invention.

FIG. 3 is a vertical cross-sectional view of a treatment device for waste liquid containing organic chlorine.

FIG. 4 is a diagram showing a result of a long-term continuous treatment of a tetrachloroethylene-containing waste liquid according to the present invention.

FIG. 5 is a diagram showing a comparison result of a treatment of a waste liquid containing tetrachloroethylene according to the present invention and a treatment of activated carbon alone.

[Explanation of symbols]

1 Surface of Porous Ceramic Particles 2 Continuous Porosity of Porous Ceramic Particles 3 Crystalline Particles in Porous Ceramic Particles 4 Flow of Treatment Object 5 Amorphous Portion of Porous Ceramic Particle Surface 6 Waste Liquid Treatment Column 7 Pore Surface Amorphous Porous Mixture of ceramics and activated carbon

   ─────────────────────────────────────────────────── ─── Continued front page       (56) Reference JP-A-4-338185 (JP, A)                 JP-A-5-105548 (JP, A)                 JP-A-61-291473 (JP, A)                 JP-A-6-305851 (JP, A)                 JP-A-60-261586 (JP, A)                 JP-A-61-136490 (JP, A)                 JP 61-153196 (JP, A)                 JP-A-6-218280 (JP, A)                 Ceramic Industry Association, "Ceramic Engineering Hand"               Book "Gihodo Co., Ltd. 1964 1964               Published March 25, p39, p. 1383 ~ p.               1389

Claims (5)

(57) [Claims] 1. A mixture of clay, a pore-forming material and water, which are appropriately mixed.
After molding into a shape, it is dried and the product temperature of the dried molded body is molded.
5-15 hours due to self-combustion of the pore-forming material in the body
Then, after raising the temperature from room temperature to 600-800 ℃, molding
Keep the body temperature at 600-800 ℃ for 3-7 hours, then
At 1200 ° C to 1500 ° C and then at this temperature
Bake for 4-8 hours, cool down and crusher
A method for producing porous ceramics having a characteristic amorphous surface . 2. A mixture of clay, a pore-forming material and water, which are appropriately mixed.
After molding into a shape, it is dried and the product temperature of the dried molded body is molded.
5-15 hours due to self-combustion of the pore-forming material in the body
Then, after raising the temperature from room temperature to 600-800 ℃, molding
Keep the body temperature at 600-800 ℃ for 3-7 hours, then
At 1200 ° C to 1500 ° C and then at this temperature
Baking for 4 to 8 hours, crushing after cooling
Porous ceramics whose pore surface is amorphous are obtained . 3. A mixture of clay, a pore-forming material, and water is added as appropriate.
After molding into a shape, it is dried and the product temperature of the dried molded body is molded.
5-15 hours due to self-combustion of the pore-forming material in the body
Then, after raising the temperature from room temperature to 600-800 ℃, molding
Keep the body temperature at 600-800 ℃ for 3-7 hours, then
At 1200 ° C to 1500 ° C and then at this temperature
Baking for 4 to 8 hours, crushing after cooling
Porous ceramics with amorphous pore surface
A method for treating wastewater and waste liquid, which is characterized by using a box . 4. A mixture of clay, a pore-forming material, and water is added as appropriate.
After molding into a shape, it is dried and the product temperature of the dried molded body is molded.
5-15 hours due to self-combustion of the pore-forming material in the body
Then, after raising the temperature from room temperature to 600-800 ℃, molding
Keep the body temperature at 600-800 ℃ for 3-7 hours, then
At 1200 ° C to 1500 ° C and then at this temperature
Baking for 4 to 8 hours, crushing after cooling
Porous ceramics with amorphous pore surface
Wastewater / waste liquid treatment agent consisting of a mixture of water and activated carbon . 5. A mixture of clay, a pore-forming material, and water is added as appropriate.
After molding into a shape, it is dried and the product temperature of the dried molded body is molded.
5-15 hours due to self-combustion of the pore-forming material in the body
Then, after raising the temperature from room temperature to 600-800 ℃, molding
Keep the body temperature at 600-800 ℃ for 3-7 hours, then
At 1200 ° C to 1500 ° C and then at this temperature
Baking for 4 to 8 hours, crushing after cooling
Porous ceramics with amorphous pore surface
Exhaust gas, characterized by using a mixture of coke and activated carbon
How to treat water and waste liquid .