Method for preparing black pottery by using low-temperature strong reduction carbon deposition process

Abstract

The invention discloses a method for preparing black pottery by using a low-temperature strong reduction carbon deposition process, which comprises the following steps: weighing raw materials, adding water, and carrying out ball milling to obtain pug; wherein part of the raw materials are from clay; manufacturing the pug into a green body in a slip casting manner; drying the green body, putting the dried green body into a gas kiln, sintering in an oxidizing atmosphere, and converting into a strong reducing atmosphere when the temperature is increased to 620 DEG C, the highest sintering temperature being 1100-1110 DEG C, and the sintering period being 4.5 h; the firing curve in the firing process is divided into six stages, in the first stage, the firing temperature is 50-350 DEG C, and the firing time is 0.5 h; in the second stage, the firing temperature is 350-550 DEG C, and the firing time is 0.5 h; in the third stage, the firing temperature is 550-620 DEG C, and the firing time is 1 h; in the fourth stage, the firing temperature is 620-980 DEG C, and the firing time is 1 h; in the fifth stage, the sintering temperature is 980 DEG C to the highest sintering temperature, and the sintering time is 1 h; in the sixth stage, the highest sintering temperature is kept for 0.5 h, slow cooling and drawing are conducted after sintering is finished, and the black pottery is obtained. The black shell of the black pottery is uniform and attractive, and the black pottery is high in strength and hardness.

Description

Technical Field

[0001] The invention belongs to the technical field of pottery preparation, and in particular relates to a method for preparing black pottery by utilizing a low-temperature strong reduction carbon deposition process. Background Art

[0002] Black pottery, which was born in the Neolithic Age in China, is an ancient Chinese pottery-making technique. It is an unglazed pottery that is processed through a series of special processes and carburized and fired at a relatively low temperature. It is characterized by being as black as lacquer, as bright as a mirror, as thin as paper, and as hard as porcelain. At present, the production and manufacture of black pottery is relatively common, but most manufacturers still have many problems in the firing process, such as insufficient body strength, not black color, black surface and gray inside, etc. In order to better inherit and develop the black pottery culture, it is urgent to improve the manufacturing process of black pottery.

[0003] The Chinese patent application number CN201210477480.1 discloses a method for preparing carbon-containing black pottery, which includes a material selection process, wherein the material selection process uses the Yellow River sediment and peony charcoal with a particle size of 10-60 μm as raw materials, and the weight ratio of the Yellow River sediment to the peony charcoal is 1.5-9:1. The method adds peony charcoal as a raw material, and the obtained black pottery is black inside and outside, uniform in color, high in hardness, low in porosity, and has a water absorption rate between 0.5-10%; the normal spectral emissivity within 8-15 μm reaches more than 85%. The carburizing effect is one of the key technologies in the black pottery process, which can give the pottery a unique black appearance and excellent physical and chemical properties. How to balance the carburizing effect and apparent porosity of black pottery through the control of raw materials and processes has become a major problem at present. Summary of the invention

[0004] In order to solve the above problems, the present invention provides a method for preparing black pottery by using a low-temperature strong reduction carbon deposition process. The carburizing effect of the present invention is good, and the color of the prepared black pottery is stable.

[0005] The technical solution of the present invention is as follows:

[0006] One of the purposes of the present invention is to provide a method for preparing black pottery by using a low-temperature strong reduction carbon deposition process, comprising the following steps:

[0007] S1: Weigh 52-56 parts of silicon dioxide, 20-23 parts of aluminum oxide, 1.2-1.5 parts of potassium oxide, 1.1-1.3 parts of sodium oxide, 0.2-0.4 parts of calcium oxide, 0.2-0.4 parts of magnesium oxide, 1.5-2 parts of titanium oxide, 8-10 parts of iron oxide, and 3-6 parts of manganese oxide, add water and perform ball milling to obtain a mud material; wherein, some of the raw materials come from clay;

[0008] S2: Making a green body from the mud obtained in step S1 by slip casting;

[0009] S3: After the green body obtained in step S2 is dried, it is placed in a gas kiln, and sintered in an oxidizing atmosphere first, and then converted to a strong reducing atmosphere when the temperature is raised to 620°C, the maximum sintering temperature is 1100-1110°C, and the firing cycle is 4.5h; wherein, the firing curve of the firing process is divided into six stages, the first stage: the firing temperature is: 50-350°C, and the firing time is 0.5h; the second stage: the firing temperature is 350-550°C, and the firing time is 0.5h; the third stage: the firing temperature is 550-620°C, and the firing time is 1h; the fourth stage: the firing temperature is 620-980°C, and the firing time is 1h; the fifth stage: the firing temperature is 980°C-the highest sintering temperature, and the firing time is 1h; the sixth stage: keep warm at the highest sintering temperature for 0.5h, and after the firing is completed, slowly cool out of the kiln to obtain the black pottery.

[0010] Furthermore, in step S1, the particle size D50 of the mud material is 7.5-8.5 μm, and the mud specific gravity is 1.75-1.80.

[0011] Furthermore, in step S1, during the ball milling process, the ratio of material: ball: water is 1:2:0.3, the rotation speed of the ball mill is 60 r / min, and the ball milling time is 4 h.

[0012] Furthermore, in step S2, the thickness of the obtained green body is 5-8 mm.

[0013] Furthermore, in step S3, at 900°C, the length of the strong reducing flame passing through the fire viewing hole is 15-20 cm.

[0014] A second object of the present invention is to provide a black pottery obtained by any of the above methods.

[0015] Furthermore, the apparent porosity of the black pottery is ≥30%.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. The present invention provides a method for preparing black pottery by using a low-temperature strong reduction carbon deposition process. During the firing process, in order to prevent cracking caused by the crystal transformation of silicon dioxide, a slow heating method is used before 620°C. The present invention controls the penetration speed and depth of carbon elements by controlling the firing temperature and firing time, and makes the apparent porosity of the blank greater than or equal to 30%, so that the apparent porosity and carburizing effect of the black pottery reach the best balance. At this time, the black pottery has good appearance and performance, and the obtained black pottery finished product has a uniform and beautiful black shell, and has good strength and hardness. Since the apparent porosity of the semi-finished product is greater than 30% when the sintering temperature is 600-1000°C, and the carburizing effect is better at this time, the present invention adopts 620°C as the conversion point of the reducing atmosphere. At about 800°C, the organic matter in the clay decomposes to form a large amount of highly active primary carbon, which is conducive to the carburizing reaction. Under the promotion of the reducing atmosphere CO and the catalysis of iron oxide, the carburizing reaction is easier to proceed. Even if the firing temperature used in the present invention is relatively low, the carburizing effect is still relatively good. At 600-1050°C, its apparent porosity is stable at about 30%, and the length of the firing time at this time has little effect on the carburizing effect of the product. Therefore, the present invention adopts a relatively low temperature and rapid firing method for firing, which can achieve the purpose of saving energy.

[0018] 2. The present invention provides a method for preparing black pottery by using a low-temperature strong reduction carbon deposition process. The black pottery has good appearance performance, its black shell is uniform and beautiful, and it has high strength and hardness. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A schematic diagram of black pottery prepared by a method for preparing black pottery by a low-temperature strong reduction carbon deposition process provided by the present invention;

[0020] Figure 2 The present invention provides a firing curve diagram of a method for preparing black pottery by utilizing a low-temperature strong reduction carbon deposition process. DETAILED DESCRIPTION

[0021] The following is in conjunction with the preferred embodiment and with reference to the attached Figure 1-2 , the present invention is further described. The endpoints and any values ​​of the ranges disclosed in the present invention are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values; for numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed herein; the materials, reagents, etc. used in the following examples, unless otherwise specified, can be obtained from commercial channels; the experimental methods in the following examples, unless otherwise specified, are all conventional methods.

[0022] Example 1

[0023] This embodiment provides a method for preparing black pottery using a low-temperature strong reduction carbon deposition process, comprising the following steps:

[0024] S1: Weigh 54 parts of silicon dioxide, 21 parts of aluminum oxide, 1.2 parts of potassium oxide, 1.2 parts of sodium oxide, 0.3 parts of calcium oxide, 0.25 parts of magnesium oxide, 1.6 parts of titanium oxide, 8.5 parts of iron oxide, and 4 parts of manganese oxide, add water and perform ball milling to obtain a mud material; some of the raw materials come from clay;

[0025] S2: Making a green body from the mud obtained in step S1 by slip casting;

[0026] S3: After the green body obtained in step S2 is dried, it is placed in a gas kiln, and sintered in an oxidizing atmosphere first, and then converted into a strong reducing atmosphere when the temperature is raised to 620°C. The maximum sintering temperature is 1110°C, and the firing cycle is 4.5h; wherein, the firing curve of the firing process is divided into six stages, the first stage: the firing temperature is: 50-350°C, and the firing time is 0.5h; the second stage: the firing temperature is 350-550°C, and the firing time is 0.5h; the third stage: the firing temperature is 550-620°C, and the firing time is 1h; the fourth stage: the firing temperature is 620-980°C, and the firing time is 1h; the fifth stage: the firing temperature is 980°C-1110°C, and the firing time is 1h; the sixth stage: keep warm at the highest sintering temperature for 0.5h, and after the firing is completed, slowly cool out of the kiln to obtain the black pottery.

[0027] In this embodiment, in step S1, the particle size D50 of the mud material is 8 μm, the mud specific gravity is 1.78, and during the ball milling process, the material: ball: water = 1:2:0.3, the rotation speed of the ball mill is 60 r / min, and the ball milling time is 4 h.

[0028] In this embodiment, in step S2, the thickness of the obtained green body is 6 mm, and in step S3, at 900°C, the length of the strong reducing flame passing through the fire viewing hole is 15-20 cm.

[0029] The black pottery obtained in this embodiment is as follows Figure 1 As shown, its apparent porosity is ≥30%.

[0030] Example 2

[0031] This embodiment provides a method for preparing black pottery using a low-temperature strong reduction carbon deposition process, comprising the following steps:

[0032] S1: Weigh 52 parts of silicon dioxide, 20 parts of aluminum oxide, 1.3 parts of potassium oxide, 1.1 parts of sodium oxide, 0.4 parts of calcium oxide, 0.2 parts of magnesium oxide, 2 parts of titanium oxide, 8 parts of iron oxide, and 3 parts of manganese oxide, add water and perform ball milling to obtain a mud material; some of the raw materials come from clay;

[0033] S2: Making a green body from the mud obtained in step S1 by slip casting;

[0034] S3: After the green body obtained in step S2 is dried, it is placed in a gas kiln, and sintered in an oxidizing atmosphere first, and then converted to a strong reducing atmosphere when the temperature is raised to 620°C. The maximum sintering temperature is 1100°C, and the firing cycle is 4.5h; wherein, the firing curve of the firing process is divided into six stages, the first stage: the firing temperature is: 50-350°C, and the firing time is 0.5h; the second stage: the firing temperature is 350-550°C, and the firing time is 0.5h; the third stage: the firing temperature is 550-620°C, and the firing time is 1h; the fourth stage: the firing temperature is 620-980°C, and the firing time is 1h; the fifth stage: the firing temperature is 980°C-1100°C, and the firing time is 1h; the sixth stage: keep warm at the highest sintering temperature for 0.5h, and after the firing is completed, slowly cool out of the kiln to obtain the black pottery.

[0035] In this embodiment, in step S1, the particle size D50 of the mud material is 8.5 μm, the mud specific gravity is 1.75, and during the ball milling process, the material: ball: water = 1:2:0.3, the rotation speed of the ball mill is 60 r / min, and the ball milling time is 4 h.

[0036] In this embodiment, in step S2, the thickness of the obtained green body is 5 mm, and in step S3, at 900°C, the length of the strong reducing flame passing through the fire viewing hole is 15-20 cm.

[0037] The apparent porosity of the black pottery prepared in this embodiment is ≥30%.

[0038] Example 3

[0039] This embodiment provides a method for preparing black pottery using a low-temperature strong reduction carbon deposition process, comprising the following steps:

[0040] S1: Weigh 56 parts of silicon dioxide, 23 parts of aluminum oxide, 1.5 parts of potassium oxide, 1.3 parts of sodium oxide, 0.2 parts of calcium oxide, 0.4 parts of magnesium oxide, 2 parts of titanium oxide, 10 parts of iron oxide, and 6 parts of manganese oxide, add water and perform ball milling to obtain a mud material; some of the raw materials come from clay;

[0041] S2: Making a green body from the mud obtained in step S1 by slip casting;

[0042] S3: After the green body obtained in step S2 is dried, it is placed in a gas kiln and sintered in an oxidizing atmosphere first. When the temperature rises to 620°C, it is converted into a strong reducing atmosphere. The maximum sintering temperature is 1105°C and the firing cycle is 4.5h. The firing curve of the firing process is divided into six stages. The first stage: the firing temperature is 50-350°C and the firing time is 0.5h. The second stage: the firing temperature is 350-550°C and the firing time is 0.5h. The third stage: the firing temperature is 550-620°C and the firing time is 1h. The fourth stage: the firing temperature is 620-980°C and the firing time is 1h. The fifth stage: the firing temperature is 980°C-1105°C and the firing time is 1h. The sixth stage: keep warm at the highest sintering temperature for 0.5h, and after the firing is completed, slowly cool the kiln to obtain the black pottery.

[0043] In this embodiment, in step S1, the particle size D50 of the mud material is 7.5 μm, the mud specific gravity is 1.80, and during the ball milling process, the material: ball: water = 1:2:0.3, the rotation speed of the ball mill is 60 r / min, and the ball milling time is 4 h.

[0044] In this embodiment, in step S2, the thickness of the obtained green body is 8 mm, and in step S3, at 900°C, the length of the strong reducing flame passing through the fire viewing hole is 15-20 cm.

[0045] The apparent porosity of the black pottery prepared in this embodiment is ≥30%.

[0046] Comparative Example 1

[0047] The difference from Example 1 is that the black pottery of this comparative example is composed of the following raw materials in parts by weight: 54 parts of silicon dioxide, 19 parts of aluminum oxide, 1.2 parts of potassium oxide, 1.2 parts of sodium oxide, 0.3 parts of calcium oxide, 0.25 parts of magnesium oxide, 0.8 parts of titanium oxide, 4 parts of iron oxide, and 2 parts of manganese oxide.

[0048] Comparative Example 2

[0049] The difference from Example 1 is that the black pottery of this comparative example is composed of the following raw materials in parts by weight: 60 parts of silicon dioxide, 24 parts of aluminum oxide, 1.2 parts of potassium oxide, 1.2 parts of sodium oxide, 0.3 parts of calcium oxide, 0.25 parts of magnesium oxide, 1.8 parts of titanium oxide, 12 parts of iron oxide, and 8 parts of manganese oxide.

[0050] Comparative Example 3

[0051] The difference from Example 1 is that the reducing atmosphere conversion point of this comparative example is 50° C., and reducing atmosphere is used throughout the sintering.

[0052] Comparative Example 4

[0053] The difference from Example 1 is that the reducing atmosphere conversion point of this comparative example is 900°C.

[0054] Comparative Example 5

[0055] The reducing atmosphere conversion point of this comparative example is 1100°C, and the temperature is kept at approximately 1110°C for 30 minutes.

[0056] Implementation effect evaluation

[0057] The following is a specific test of the black pottery obtained by Examples 1-3 and Comparative Examples 1-5 to further illustrate the excellent effect achieved by the present invention. The test results are shown in the following table:

[0058] Table 1 Performance test results statistics

[0059]

[0060]

[0061] It can be seen from the data in the above table that the black pottery prepared in Example 1 has a uniform and beautiful black shell, so Example 1 is used as a blank control sample. The color and strength of the black pottery in Examples 2 and 3 are both qualified. The pottery prepared in Example 1 is grayish in color. The pottery prepared in Example 2 is brownish black, deviating from the color of black pottery. The pottery prepared in Example 3 is grayish and has no black pottery color. The pottery prepared in Example 4 is brownish brown, deviating from the color of black pottery. The black pottery prepared in Example 5 is light gray and has no black pottery color. And the strength of the pottery in Examples 1-5 is reduced. It shows that the black pottery prepared by the method for preparing black pottery using a low-temperature strong reduction carbon deposition process provided by the present invention has good appearance performance, its black shell is uniform and beautiful, and its strength is high.

[0062] The above is only a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several modifications and improvements without departing from the inventive concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A method for preparing black pottery using a low-temperature strong reduction carbon deposition process, characterized in that: The following steps are involved: S1: Weigh 52-56 parts of silicon dioxide, 20-23 parts of aluminum oxide, 1.2-1.5 parts of potassium oxide, 1.1-1.3 parts of sodium oxide, 0.2-0.4 parts of calcium oxide, 0.2-0.4 parts of magnesium oxide, 1.5-2 parts of titanium oxide, 8-10 parts of iron oxide, and 3-6 parts of manganese oxide, add water and perform ball milling to obtain a mud material; wherein, some of the raw materials come from clay; S2: Making a green body from the mud obtained in step S1 by slip casting; S3: After the green body obtained in step S2 is dried, it is placed in a gas kiln, and sintered in an oxidizing atmosphere first, and then converted to a strong reducing atmosphere when the temperature is raised to 620°C, the maximum sintering temperature is 1100-1110°C, and the firing cycle is 4.5h; wherein, the firing curve of the firing process is divided into six stages, the first stage: the firing temperature is: 50-350°C, and the firing time is 0.5h; the second stage: the firing temperature is 350-550°C, and the firing time is 0.5h; the third stage: the firing temperature is 550-620°C, and the firing time is 1h; the fourth stage: the firing temperature is 620-980°C, and the firing time is 1h; the fifth stage: the firing temperature is 980°C-the highest sintering temperature, and the firing time is 1h; the sixth stage: keep warm at the highest sintering temperature for 0.5h, and after the firing is completed, slowly cool out of the kiln to obtain the black pottery.

2. The method for preparing black pottery by using a low-temperature strong reduction carbon deposition process according to claim 1, characterized in that: In step S1, the particle size D50 of the mud material is 7.5-8.5 μm, and the mud specific gravity is 1.75-1.

80.

3. The method for preparing black pottery by using a low-temperature strong reduction carbon deposition process according to claim 1, characterized in that: In step S1, during the ball milling process, material: ball: water = 1: 2:0.3, the speed of the ball mill is 60r / min, and the ball milling time is 4h.

4. The method for preparing black pottery by using a low-temperature strong reduction carbon deposition process according to claim 1, characterized in that: In step S2, the thickness of the obtained green body is 5-8 mm.

5. The method for preparing black pottery by using a low-temperature strong reduction carbon deposition process according to claim 1, characterized in that: In step S3, at 900°C, the strong reducing flame passes through the fire viewing hole for a length of 15-20 cm.

6. Black pottery obtained according to the method for preparing black pottery using a low-temperature strong reduction carbon deposition process as described in any one of claims 1 to 5.

7. The black pottery prepared by the method for preparing black pottery by low temperature strong reduction carbon deposition process according to claim 6 is characterized in that: The apparent porosity of the black pottery is ≥30%.

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