Mud composition for preparing ceramic product, ceramic product and preparation method of ceramic product

Abstract

The invention relates to a pug composition for preparing a ceramic product, the ceramic product and a preparation method of the ceramic product. The pug composition comprises the following components in parts by weight: 40-60 parts of red soil, and the red soil comprises 7-11 wt% of iron element, 65-70 wt% of silicon dioxide and 19-23 wt% of aluminum oxide; 10-20 parts of iron-rich kaolin, and the content of iron element in the iron-rich kaolin is 7-10 wt%; the content of aluminum oxide in the mullite is 75 to 85 weight percent, and the content of aluminum oxide in the mullite is 10 to 20 weight percent. According to the clay composition disclosed by the invention, the clay, the iron-rich kaolin and the mullite containing specific components are combined and are scientifically proportioned, so that the high temperature resistance of a ceramic product is improved, meanwhile, the ceramic product can bear severe temperature change, and the ceramic product is not easy to deform and crack in the firing process.

Description

Technical Field

[0001] This invention belongs to the field of ceramic technology, specifically relating to a clay composition for preparing ceramic products, ceramic products, and a method for preparing the same. Background Technology

[0002] A charcoal stove is a stove that uses charcoal as fuel, primarily made of ceramic. As an ancient heating tool, the charcoal stove continues to play an important role in modern life due to its unique heating method and high-temperature characteristics. Under ideal combustion conditions, the temperature of charcoal fire can reach very high levels, giving charcoal stoves unique advantages in certain situations. For example, in cooking, the high temperature of a charcoal stove can quickly cook food, preserving its original flavor.

[0003] Existing ceramic charcoal kilns are mainly made of Chaozhou red clay, high-temperature ceramic, and composite square clay, which cannot withstand long-term combustion at temperatures above 600℃, otherwise cracking and damage are likely to occur. In order to achieve the high-temperature resistance of the charcoal kiln, higher requirements are placed on the high-temperature resistance and thermal shock stability of the ceramic materials; at the same time, the firing process is also more difficult, making it easier for deformation and cracking to occur, resulting in a decrease in the yield. Summary of the Invention

[0004] Therefore, the technical problem to be solved by this application is how to improve the high-temperature resistance of ceramic products while reducing the deformation and cracking rate during the firing process.

[0005] To address the aforementioned technical problems, this application provides the following technical solution: In a first aspect, this application provides a clay composition for preparing ceramic products, comprising the following components in parts by weight: The laterite contains 40-60 parts of iron, 7-11 wt% iron, 65-70 wt% silicon dioxide, and 19-23 wt% aluminum oxide. 10-20 parts of iron-rich kaolin, wherein the iron content in the iron-rich kaolin is 7-10 wt%; 10-20 parts of mullite, wherein the content of aluminum oxide in the mullite is 75-85 wt%.

[0006] In some embodiments of this application, the composition comprises the following components in parts by weight: 50-60 parts laterite, 10-15 parts iron-rich kaolinite, and 15-20 parts mullite.

[0007] In some embodiments of this application, the laterite contains 8.5–10.5 wt% iron, 65–68 wt% silicon dioxide, and 19–20 wt% aluminum oxide. And / or, the iron content in the iron-rich kaolin is 8-10 wt%; And / or, the silica content in the mullite is 10-23 wt%, preferably 18-23 wt%.

[0008] Secondly, this application provides a ceramic product prepared by steps including shaping and firing the above-mentioned clay composition. Preferably, the ceramic product includes a charcoal furnace body, a charcoal furnace ring, or a charcoal furnace chamber.

[0009] Thirdly, this application provides a method for preparing the above-mentioned ceramic article, which includes the following steps: S11. Mix the clay composition with water to prepare a raw material for the green body; S12. The raw material is pulled and trimmed to produce ceramic product blanks; S13. Ceramic products are obtained by firing ceramic blanks.

[0010] Fourthly, this application provides a multilayer composite ceramic article, comprising: The unglazed layer is made by using the above-mentioned clay composition as a raw material; The glaze layer covering the surface of the body layer is made by using a glaze composition as raw material, wherein the glaze composition comprises the following components in parts by weight: 60-80 parts glaze ore, 10-20 parts glaze ash, 1-5 parts potassium feldspar, 1-5 parts limestone, 1-5 parts kaolinite, and 5-10 parts iron oxide red.

[0011] In some embodiments of this application, the glaze composition comprises the following components by weight: 60-70 parts glaze ore, 10-15 parts glaze ash, 3-5 parts potassium feldspar, 3-5 parts limestone, 3-5 parts kaolinite, and 7-10 parts iron oxide red. Preferably, the glaze ore comprises 7-10 wt% ferric oxide, 5-8 wt% calcium oxide, 40-60 wt% silicon dioxide and 15-20 wt% aluminum oxide; More preferably, the glaze ash is prepared by a method comprising: S241. Obtain wolfsbane ash by burning it in an oxygen-deficient environment; S242. Wet ash paste is obtained by dissolving and separating wolfberry ash; S243. The wet ash paste is dried and ground to obtain glaze ash.

[0012] Fifthly, this application provides a method for preparing the above-mentioned multilayer composite ceramic product, which includes the following steps: S21. Mix the clay composition with water to prepare a raw material for the green body; S22. To shape the billet material into a billet by pulling and trimming it; S23. The green body is first fired to obtain a green body layer; S24. Mix the glaze composition with water to prepare a glaze slurry; S25. Apply the glaze slurry obtained in step S24 to the surface of the green body layer obtained in step S23, and perform a second firing to obtain the multi-layer composite ceramic product.

[0013] In some embodiments of this application, the second calcination in step S25 includes the following steps: first, heating to 800-1000°C and holding for 3-5 hours, and then heating to 1250-1300°C in a reducing atmosphere and holding for 40-50 hours.

[0014] In some embodiments of this application, after the roasting in step S25, a cooling step is further included, wherein the cooling curve is: cooling to 950-1050°C at 0.5-2°C / min, and then cooling to room temperature at 8-12°C / min.

[0015] Beneficial effects: The clay composition of this application uses a scientifically proportioned combination of red clay, iron-rich kaolin, and mullite containing specific components to improve the high-temperature resistance of ceramic products while enabling them to withstand drastic temperature changes, making them less prone to deformation and cracking during firing. It also enhances the chemical resistance of ceramic products, providing excellent resistance to furnace ash and gases, and making them less susceptible to chemical corrosion.

[0016] The multi-layer composite ceramic product of this application adds a glaze layer on the unglazed body layer, which further improves the hardness and refractoriness of the ceramic product, and the glaze surface is uniform, beautiful and attractive. Detailed Implementation

[0017] The present invention will now be described in detail with reference to embodiments. The principles and features of the present invention are described below with reference to embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other. The embodiments given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0018] In this application, thermal shock resistance refers to the property of a material and its articles to resist drastic temperature changes without damage or destruction. For example, the thermal shock resistance of a material and its articles can be evaluated by heating the sample to 200°C, holding it at that temperature for 10 minutes, and then immersing it in running water at 20°C for 5 minutes, observing whether cracks occur.

[0019] In this application, the natural mineral raw materials such as laterite and glaze ore, apart from the main components listed or known in the prior art, consist of "unavoidable impurities" or "natural associated components." Experiments have confirmed that these trace impurities do not have a substantial impact on the thermal shock resistance of the ceramic products of this invention or the deformation and cracking rate during the firing process.

[0020] Unless otherwise stated or in case of contradiction, the terms or phrases used herein shall have the following meanings: The terms "and / or," "or / and," and "and / or" as used in this application encompass any one of two or more related listed items, as well as any and all combinations of the related listed items. These arbitrary and all combinations include any two related listed items, any more related listed items, or a combination of all related listed items. It should be noted that when at least three items are connected using at least two conjunctions selected from "and / or," "or / and," and "and / or," it should be understood that in this application, the technical solution undoubtedly includes solutions connected by "logical AND," and also undoubtedly includes solutions connected by "logical OR." For example, "A and / or B" includes three parallel solutions: A, B, and "a combination of A and B."

[0021] In this application, terms such as "preferred", "more preferred", "better", and "suitable" are merely used to describe implementation methods or embodiments that have better effects, and should be understood not to constitute a limitation on the scope of protection of this application.

[0022] In this application, "optionally," "optionally," and "optional" mean that something is optional, that is, it means that it is selected from either "with" or "without." If there are multiple "optional" entries in a technical solution, unless otherwise specified, and there are no contradictions or mutual constraints, each "optional" entry shall be independent.

[0023] In this application, terms such as "further," "even more," and "particularly" are used for descriptive purposes and to indicate differences in content, but should not be construed as limiting the scope of protection of this application.

[0024] In this invention, the terms "first aspect," "second aspect," "third aspect," and "fourth aspect," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or quantity, nor should they be construed as implicitly indicating the importance or quantity of the indicated technical features. Moreover, "first," "second," "third," and "fourth," etc., serve only as a non-exhaustive enumeration and should be understood not to constitute a closed limitation on quantity.

[0025] In this application, the technical features described in an open-ended manner include both closed technical solutions consisting of the listed features and open technical solutions that include the listed features.

[0026] In this application, numerical intervals (i.e., numerical ranges) are involved. Unless otherwise specified, the selected numerical distributions within the aforementioned numerical intervals are considered continuous, and include the two endpoints (i.e., the minimum and maximum values) of the numerical range, as well as every value between these two endpoints. Unless otherwise specified, when the numerical interval refers only to the integers within that interval, it includes the two endpoint integers of the numerical range, as well as every integer between the two endpoints. In this document, this is equivalent to directly listing every integer. For example, if t is an integer selected from 1 to 10, it means that t is any integer selected from the group of integers consisting of 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10.

[0027] Furthermore, when multiple scopes are provided to describe a feature or characteristic, these scopes may be merged. In other words, unless otherwise specified, the scopes disclosed herein should be understood to include any and all subscopes to which they are included.

[0028] Unless otherwise specified, the temperature parameters in this application are permitted to be either constant-temperature treatment or variations within a certain temperature range. It should be understood that the constant-temperature treatment allows temperature fluctuations within the precision range of the instrument control, such as ±5℃, ±4℃, ±3℃, ±2℃, or ±1℃.

[0029] In this application, wt% represents weight percentage.

[0030] In this application, "room temperature" generally refers to 5℃ to 30℃, and more preferably 25±5℃.

[0031] In a first aspect, this application provides a clay composition for preparing ceramic products, comprising the following components in parts by weight: Laterite: 40-60 parts, wherein the laterite contains 7-11 wt% iron, 65-70 wt% silicon dioxide, and 19-23 wt% aluminum oxide; Iron-rich kaolin: 10-20 parts, wherein the iron content in the iron-rich kaolin is 7-10 wt%; Mullite: 10-20 parts, of which the content of aluminum oxide is 75-85 wt%.

[0032] In some embodiments of this application, the mud composition comprises the following components in parts by weight: 50-60 parts of laterite, 10-15 parts of kaolinite, and 15-20 parts of mullite.

[0033] In some embodiments of this application, the mud composition may optionally include 45 parts by weight, 46 parts by weight, 47 parts by weight, 48 parts by weight, 49 parts by weight, 50 parts by weight, 51 parts by weight, 52 parts by weight, 53 parts by weight, 54 parts by weight, or 55 parts by weight of the laterite, or may be a range of any two of the aforementioned values.

[0034] In some embodiments of this application, the mud composition may optionally include 10 parts by weight, 11 parts by weight, 12 parts by weight, 13 parts by weight, 14 parts by weight, 15 parts by weight, 16 parts by weight, 17 parts by weight, 18 parts by weight, 19 parts by weight, or 20 parts by weight of the iron-rich kaolin, or may be a range of any two of the aforementioned values.

[0035] In some embodiments of this application, the mud composition may optionally include 10 parts by weight, 11 parts by weight, 12 parts by weight, 13 parts by weight, 14 parts by weight, 15 parts by weight, 16 parts by weight, 17 parts by weight, 18 parts by weight, 19 parts by weight, or 20 parts by weight of the mullite, or may be a range of any two of the aforementioned values.

[0036] This application uses red clay with a specific composition, in which the iron content is between 7% and 11%. The high iron content of the red clay gives the ceramic products a unique "iron body" property during the firing process, making them hard and magnetic. Silica and other components work together to form a hard texture. Alumina can improve the hardness and refractoriness of the ceramic products.

[0037] In this application, kaolin refers to clay containing kaolinite as its main component. The kaolinite content can be ≥60wt%, ≥70wt%, ≥80wt%, or ≥90wt%, for example, 70-80wt%, and further 75-80wt%. Ordinary kaolin typically contains less than 2% iron. Compared to ordinary kaolin, the iron-rich kaolin of this application has a high iron content, reaching 7-10%, exhibiting a unique "iron core" property. This improves the refractoriness and plasticity of the clay, and when scientifically proportioned with other components, it can improve high-temperature resistance and reduce deformation and blistering problems at high temperatures while retaining sufficient iron content.

[0038] The mullite in this application contains 75-85% aluminum oxide, which increases the melting point to above 1810℃ and the refractoriness to above 1800℃. This improves the high-temperature resistance of ceramic products and enables them to withstand drastic temperature changes (rapid heating and cooling), making them less prone to cracking and deformation.

[0039] In some embodiments of this application, the iron content in the laterite is 8.5 to 10.5 wt%, preferably 8.5 to 9.5 wt%.

[0040] In some embodiments of this application, the silica content in the laterite is 65-68 wt%, preferably 66-68 wt%.

[0041] In some embodiments of this application, the content of aluminum oxide in the laterite is 19-20 wt%.

[0042] In some embodiments of this application, the kaolinite content in the kaolin is greater than or equal to 60 wt%, preferably 60-90 wt%, more preferably 60-80 wt%, and even more preferably 75-80 wt%.

[0043] In some embodiments of this application, the silica content in the mullite is 10-23 wt%, preferably 18-23 wt%.

[0044] In some embodiments of this application, the content of aluminum oxide in the mullite is 75-80 wt%.

[0045] In some embodiments of this application, the iron content in the laterite can be 7wt%, 7.5wt%, 8wt%, 8.5wt%, 9wt%, 9.5wt%, 10wt%, 10.5wt%, or 11wt%, or it can be a range of any two of the aforementioned values.

[0046] In some embodiments of this application, the silica content in the laterite can be 65wt%, 66wt%, 67wt%, 68wt%, 69wt%, or 70wt%, or it can be a range of any two of the aforementioned values.

[0047] In some embodiments of this application, the aluminum oxide content in the laterite can be 19wt%, 20wt%, 21wt%, 22wt%, or 23wt%, or it can be a range of any two of the aforementioned values.

[0048] In some embodiments of this application, the iron content in the kaolin can be 7wt%, 7.5wt%, 8wt%, 8.5wt%, 9wt%, 9.5wt%, or 10wt%, or it can be a range of any two of the aforementioned values.

[0049] In some embodiments of this application, the aluminum oxide content in the mullite can be 75wt%, 76wt%, 77wt%, 78wt%, 79wt%, 80wt%, 81wt%, 82wt%, 83wt%, 84wt%, or 85wt%, or it can be a range of any two of the aforementioned values.

[0050] In some embodiments of this application, the silica content in the mullite can be 10wt%, 11wt%, 12wt%, 13wt%, 14wt%, 15wt%, 16wt%, 17wt%, 18wt%, 19wt%, 20wt%, 21wt%, 22wt%, or 23wt%, or a range consisting of any two of the aforementioned values.

[0051] Secondly, this application provides a ceramic article which is prepared by steps including shaping and firing the above-mentioned clay composition.

[0052] In some embodiments of this application, the ceramic product is a charcoal stove assembly, which includes a charcoal stove body, a charcoal stove ring, or a charcoal stove chamber. The charcoal stove body is a cylindrical structure open at one end, the ring is a circular structure, and the chamber is a frustum shape open at both the top and bottom.

[0053] In some embodiments of this application, the diameter of the charcoal furnace body is 15-25cm, the height is 20-30cm, and the wall thickness is 0.5-2cm.

[0054] In some embodiments of this application, the inner diameter of the charcoal stove ring is 5-10cm, the outer diameter is 15-25cm, and the thickness is 0.5-2cm.

[0055] In some embodiments of this application, the upper opening diameter of the furnace is 8-12cm, the lower opening diameter is 10-12cm, the furnace height is 10-15cm, and the wall thickness is 0.5-2cm.

[0056] Thirdly, this application provides a method for preparing the above-mentioned ceramic article, which includes the following steps: S11. Mix the above-mentioned clay composition with water to prepare a raw material for the blank; S12. The raw material is pulled and trimmed to produce ceramic product blanks; S13. Ceramic products are obtained by firing ceramic blanks.

[0057] In some embodiments of this application, step S11 includes mixing the components in the clay composition to obtain clay, and then washing, filtering, drying, kneading and extruding it to obtain raw material for the blank.

[0058] Specifically, the preparation method of ceramic products includes the following steps: (1) Mixing mud: Weigh out each component of the clay composition and mix them to obtain the clay body.

[0059] (2) Practicing clay: The clay is washed, sieved, and dried to a moisture content of 20-30%, then kneaded and pressed to remove air from the clay, making the clay structure uniform and dense (kneading and pressing are repeated more than 300 times). (3) Throwing and trimming: The clay is pulled into the shape of a ceramic product, then dried to a moisture content of 8-15% and trimmed to obtain the ceramic product blank.

[0060] (4) Roasting: Ceramic products are obtained by firing ceramic blanks.

[0061] In some embodiments of this application, the roasting temperature in step S13 is 800-1000°C, and the roasting time is preferably 4-12 hours.

[0062] In this application, "refining" refers to correcting and polishing ceramic products formed by throwing to make the ceramic products have smooth lines, uniform thickness, and beautiful appearance.

[0063] Fourthly, this application provides a multilayer composite ceramic article, comprising: The unglazed body layer and the glaze layer covering the surface of the unglazed body layer are comprising a clay composition as raw material, wherein the clay composition comprises the following components by weight: 40-60 parts of laterite, wherein the laterite contains 7-11 wt% iron, 65-70 wt% silicon dioxide, and 19-23 wt% aluminum oxide; 10-20 parts of kaolin, wherein the kaolin contains 7-10 wt% iron; and 10-20 parts of mullite, wherein the mullite contains 75-85 wt% aluminum oxide. The glaze layer is made by using a glaze composition as raw material, wherein the glaze composition comprises the following components in parts by weight: glaze ore: 60-80 parts, glaze ash: 10-20 parts, potassium feldspar: 1-5 parts, limestone: 1-5 parts, kaolin: 1-5 parts, and iron oxide red: 5-10 parts.

[0064] In some embodiments of this application, the green layer is prepared by a process of shaping and firing the clay composition.

[0065] In some embodiments of this application, the glaze layer is prepared by a step including coating a glaze composition onto a green body and firing it.

[0066] In some embodiments of this application, the glaze composition comprises the following components in parts by weight: 60-70 parts glaze ore, 10-15 parts glaze ash, 3-5 parts potassium feldspar, 3-5 parts limestone, 3-5 parts kaolinite, and 7-10 parts iron oxide red.

[0067] In some embodiments of this application, the glaze composition may include 60 parts by weight, 65 parts by weight, 70 parts by weight, 75 parts by weight, or 80 parts by weight of glaze ore, or may be a range of any two of the aforementioned values.

[0068] In some embodiments of this application, the glaze composition may include 10 parts by weight, 11 parts by weight, 12 parts by weight, 13 parts by weight, 14 parts by weight, 15 parts by weight, 16 parts by weight, 17 parts by weight, 18 parts by weight, 19 parts by weight, or 20 parts by weight of glaze ash, or may be a range of any two of the aforementioned values.

[0069] In some embodiments of this application, the glaze composition may include 1 part by weight, 2 parts by weight, 3 parts by weight, 4 parts by weight, or 5 parts by weight of potassium feldspar, or may be a range of any two of the aforementioned values.

[0070] In some embodiments of this application, the glaze composition may include 1 part by weight, 2 parts by weight, 3 parts by weight, 4 parts by weight, or 5 parts by weight of limestone, or may be a range of any two of the aforementioned values.

[0071] In some embodiments of this application, the glaze composition may include 1 part by weight, 2 parts by weight, 3 parts by weight, 4 parts by weight, or 5 parts by weight of kaolin, or may be a range of any two of the aforementioned values.

[0072] In some embodiments of this application, the glaze composition may include 5 parts by weight, 6 parts by weight, 7 parts by weight, 8 parts by weight, 9 parts by weight, or 10 parts by weight of iron oxide red, or may be a range of any two of the aforementioned values.

[0073] In some embodiments of this application, the glaze mineral comprises: 7-10 wt% ferric oxide, 5-8 wt% calcium oxide, 40-60 wt% silicon dioxide, and 15-20 wt% aluminum oxide. This unique glaze mineral composition forms the distinctive glaze color and patterns of Jian ware during the firing process.

[0074] In some embodiments of this application, the content of ferric oxide in the glaze ore can be 7wt%, 8wt%, 9wt%, or 10wt%, or it can be a range of any two of the aforementioned values.

[0075] In some embodiments of this application, the calcium oxide content in the glaze ore can be 5wt%, 6wt%, 7wt%, or 8wt%, or it can be a range of any two of the aforementioned values.

[0076] In some embodiments of this application, the silica content in the glaze ore can be 40wt%, 45wt%, 50wt%, 55wt%, or 60wt%, or it can be a range of any two of the aforementioned values.

[0077] In some embodiments of this application, the aluminum oxide content in the glaze ore can be 15wt%, 16wt%, 17wt%, 18wt%, 19wt%, or 20wt%, or it can be a range of any two of the aforementioned values.

[0078] In some embodiments of this application, the glaze is prepared by a method comprising the following steps: S241. Obtain wolfsbane ash by burning it in an oxygen-deficient environment; S242. Wet ash paste is obtained by dissolving and separating wolfberry ash; S243. The wet ash paste is dried and ground to obtain glaze ash.

[0079] Wolfsbane (Miscanthus sinensis) ash is rich in potassium, while containing very little iron, titanium, or other coloring impurities, resulting in a pure white ash. In some implementations, the wolfsbane must be thoroughly cleaned and dried before burning to prevent the contamination of soil and other impurities.

[0080] In some embodiments, the method of oxygen-deficient combustion is not particularly limited, as long as it can achieve the purpose of the present invention. For example, a covering method, a sealing method, or a dilution method can be used. The covering method involves directly covering the fire source with a non-combustible material to isolate oxygen; the sealing method involves restricting oxygen supply by enclosing a space; and the dilution method involves injecting inert gas into the fire source to reduce the oxygen ratio.

[0081] Specifically, the oxygen-deficient combustion method of this application includes the following steps: 1. Pile up the wolfsbane on the ground or in a container; 2. Ignite it from the top and let it burn from top to bottom; 3. When the open flame diminishes and the entire flame appears as a bright red charcoal fire, cover the surface with soil or ash to isolate some of the air and allow it to slowly "smother" into wolfberry ash.

[0082] The temperature of the red-hot charcoal is 600-800℃.

[0083] In some implementations, when covering the surface of the charcoal fire with soil or ash, the covering thickness is 5-10 cm to maintain the charcoal fire burning under partially oxygen-deficient conditions.

[0084] In some embodiments of this application, step S241 further includes the step of sieving the ash of *Cynanchum paniculatum*.

[0085] The raw ash produced directly from firing cannot be used directly for glaze preparation because it contains soluble salts (such as potassium carbonate). These substances can make the glaze slurry unstable, prone to sedimentation, and may cause problems with the glaze surface during firing. Therefore, it is necessary to "refine the ash" (also known as "washing the ash" or "soaking the ash").

[0086] In some embodiments of this application, in order to improve the separation effect, step S242 includes soaking wolfberry ash and water at a weight ratio of 1:5 to 50, preferably for 30 to 90 days.

[0087] In some embodiments of this application, the separation described in step S242 includes filtering.

[0088] In some embodiments of this application, the glaze ash also undergoes an aging process, preferably for a period of one year or more. Longer aging periods (several months to several years) result in more stable performance.

[0089] Fifthly, this application also provides a method for preparing a multilayer composite ceramic product, which includes the following steps: S21. Mix the above-mentioned clay composition with water to prepare a raw material for the blank; S22. To shape the billet material into a billet by pulling and trimming it; S23. The ceramic product body is first fired to obtain a green body layer; S24. Mix the glaze composition with water to prepare a glaze slurry; S25. Apply the glaze slurry obtained in step S24 to the surface of the green body layer in step S23, and perform a second firing to obtain the multi-layer composite ceramic product.

[0090] In some embodiments of this application, the solid content of the glaze slurry in step S24 is 50-70 wt%.

[0091] In some embodiments of this application, the second calcination in step S25 includes the following steps: first, heating to 800-1000°C and holding for 3-5 hours, and then heating to 1250-1300°C in a reducing atmosphere and holding for 40-50 hours.

[0092] In some embodiments of this application, after the roasting in step S25, a cooling step is further included, wherein the cooling curve is: cooling to 950-1050°C at 0.5-2°C / min, and then cooling to room temperature at 8-12°C / min.

[0093] During the firing process, under reducing atmosphere conditions, such as an artificially created oxygen-deficient environment, ferric oxide in the glaze is reduced to magnetite. At a specific temperature (approximately 1200–1300°C), the iron oxide and iron-reducing elements reach a supersaturated state. With the slow cooling process, various forms of crystals precipitate in the glaze layer, forming a unique glaze effect.

[0094] Sixthly, this application also provides a glaze composition comprising the following components in parts by weight: 6-80 parts of glaze ore, 10-20 parts of glaze ash, 1-5 parts of potassium feldspar, 1-5 parts of limestone, 1-5 parts of kaolin, and 5-10 parts of iron oxide red.

[0095] In some embodiments of this application, the glaze mineral comprises: 7-10 wt% ferric oxide, 5-8 wt% calcium oxide, 40-60 wt% silicon dioxide, and 15-20 wt% aluminum oxide. This unique glaze mineral composition forms the distinctive glaze color and patterns of Jian ware during the firing process.

[0096] It should be noted that the sources of potassium feldspar, limestone, kaolin, and iron oxide in the glaze composition or glaze slurry are not particularly limited, as long as they can achieve the purpose of this invention.

[0097] Seventhly, this application also provides the use of the above-mentioned glaze composition in ceramic articles.

[0098] The beneficial effects of this application will be illustrated below through specific embodiments.

[0099] All raw materials and reagents used in this invention were purchased from mainstream manufacturers on the market. Those without specified manufacturers or concentrations are all analytical grade raw materials or reagents that are routinely available. There are no particular restrictions as long as they achieve the intended effect. The instruments and equipment used in this embodiment were all purchased from major manufacturers on the market. There are no particular limitations as long as they achieve the intended effect. Where specific techniques or conditions are not specified in this embodiment, they shall be performed in accordance with the techniques or conditions described in the literature in this field or according to the product instructions.

[0100] In the embodiments and comparative examples of this application, The chemical composition of potassium feldspar is as follows: 67 wt% silicon dioxide, 17% aluminum oxide, 0.22% calcium oxide, 11.2% potassium oxide, 2.7% sodium oxide, with the balance being other components.

[0101] Limestone must meet the following quality requirements: CaO ≥ 51 wt%, SiO2 ≤ 3 wt%, MgO ≤ 2.5 wt%, Fe2O3 ≤ 0.15 wt%.

[0102] The content of ferric oxide in iron red is greater than or equal to 99 wt%.

[0103] The chemical composition of low-iron kaolin is as follows: 80 wt% kaolinite, 1.5 wt% iron, and the remainder is other components.

[0104] Example 1 Embodiment 1 provides a ceramic charcoal stove body, wherein the stove body is a cylindrical structure with one end open and having a receiving cavity. The diameter of the cylinder is 20 cm, the thickness of the cylinder wall is 1 cm, and the height of the cylinder is 23 cm. Its preparation method is as follows: 1. Prepare the clay Weigh out 50 kg of red soil, 15 kg of iron-rich kaolin and 15 kg of mullite respectively, and mix them to obtain the body soil.

[0105] The red clay was purchased from Lin Jian'an Clay Factory in Jianyang City, with an iron content of 8.5%, a silicon dioxide content of 68%, and an aluminum oxide content of 20%. The iron-rich kaolin was purchased from Weiwei Clay Factory in Shuiji, Jianyang City. It contains 80 wt% kaolinite and 8% iron. The mullite was purchased from Jianyang Chen Xiaohua Clay Factory, and it contains 80% aluminum oxide and 18% silicon dioxide.

[0106] 2. Practicing clay: The clay is washed with water, sieved, and then screened through an 80-mesh sieve to remove impurities. It is then sun-dried for 20 days until the moisture content is 20% to 30%.

[0107] Then, the clay is repeatedly kneaded, squeezed, and expelled to remove air, making the clay structure uniform and dense. The kneading and squeezing are repeated more than 300 times.

[0108] 3. Throwing: The clay is manually pulled into the required shape of the furnace body on a rotating wheel and then allowed to air dry naturally.

[0109] 4. Trimming: After the furnace body is naturally air-dried to a moisture content of 8% to 15%, it is finely repaired with a repair knife to remove excess parts, correct the shape, and polish the surface to make the furnace body smooth, uniform in thickness, and beautiful.

[0110] 5. Plain roasting: The shaped furnace body blanks are placed into the kiln and fired at 800℃ for 8 hours. After cooling, the blanks are removed from the kiln to obtain the unglazed layer of the furnace body. The deformation and cracking of the unglazed products are observed, and the deformation and cracking rate of the unglazed layer is calculated. The deformation and cracking rate is calculated as follows: (Number of deformation and cracks / Total number of cracks) × 100%.

[0111] 6. Prepare the glaze slurry: Weigh out 70kg of glaze ore, 15kg of glaze ash, 3kg of potassium feldspar, 3kg of limestone, 3kg of low-iron kaolin, and 7kg of iron oxide. Add all the above components to 70kg of water and then ball mill them to make a fine glaze slurry.

[0112] The preparation method of the glaze ash is as follows: Pile up some wolfberry grass on the ground, ignite it from the top, and let it burn from top to bottom. When the open flames diminish and the whole thing turns into a bright red charcoal fire (about 700℃), cover the surface with soil to a thickness of about 5cm to isolate some air, and let it simmer for 4 hours to obtain wolfberry grass ash. Then, add water at a mass ratio of 1:10 and soak for 30 days. After filtering, obtain wet ash paste, which is then dried and ground to obtain glaze ash.

[0113] The glaze ore is sourced from Jianyang District, Nanping City, Fujian Province, and contains 10wt% ferric oxide, 6wt% calcium oxide, 60wt% silicon dioxide, and 20wt% aluminum oxide.

[0114] 7. Glazing Immerse the furnace body in the glaze, let it stand for 10-20 seconds, and then remove it.

[0115] 8. Roasting The glazed furnace body is placed into the firing kiln and fired at 900℃ for 4 hours. Then, it is fired at 1300℃ for 44 hours under a reducing atmosphere. Wet materials are added to the kiln to ensure firing under a reducing atmosphere.

[0116] 9. Cooling and unloading from the kiln: After calcination, the cooling rate is controlled to room temperature before the product is removed from the kiln. The cooling rate curve is as follows: cooling to 900℃ at 1℃ / min, and then cooling to room temperature at 10℃ / min.

[0117] 10. Finished product inspection: After the products are removed from the kiln, the glazed products are inspected to observe their deformation and cracking. The deformation and cracking rate is calculated as follows: Deformation and cracking rate = Number of deformed and cracked products / Total number of products × 100%.

[0118] Example 2 Embodiment 2 provides a ceramic charcoal stove body, wherein the stove body is a cylindrical structure with one end open and having a receiving cavity. The diameter of the cylinder is 20 cm, the thickness of the stove wall is 1 cm, and the height of the cylinder is 23 cm. Its preparation method is as follows: 1. Prepare the clay Weigh out 40 kg of red soil, 20 kg of iron-rich kaolin and 10 kg of mullite respectively, and mix them to obtain the body soil.

[0119] The red clay was purchased from Lin Jian'an Clay Factory in Jianyang City, with an iron content of 10.5%, a silicon dioxide content of 65%, and an aluminum oxide content of 19%. The iron-rich kaolin was purchased from Jianyang City Shuiji Weiwei Clay Factory, which contains 70 wt% kaolinite and 10% iron.

[0120] The mullite was purchased from Jianyang Chen Xiaohua Clay Factory, and it contains 75% aluminum oxide and 23% silicon dioxide.

[0121] 2. Practicing clay: The clay is washed with water, sieved, and then screened through an 80-mesh sieve to remove impurities. It is then sun-dried for 20 days until the moisture content is 20% to 30%.

[0122] Then, the clay is repeatedly kneaded, squeezed, and expelled to remove air, making the clay structure uniform and dense. The kneading and squeezing are repeated more than 300 times.

[0123] 3. Throwing: The clay is manually pulled into the required shape of the furnace body on a rotating wheel and then allowed to air dry naturally.

[0124] 4. Trimming: After the furnace body is naturally air-dried to a moisture content of 8% to 15%, it is finely repaired with a repair knife to remove excess parts, correct the shape, and polish the surface to make the furnace body smooth, uniform in thickness, and beautiful.

[0125] 5. Roasting: The shaped furnace body blanks are placed into the kiln and fired at 900℃ for 8 hours. After cooling, the blanks are removed from the kiln to obtain the unglazed layer of the furnace body. The deformation and cracking of the unglazed products are observed, and the deformation and cracking rate of the unglazed layer is calculated. The deformation and cracking rate is calculated as follows: (Number of deformation and cracks / Total number of cracks) × 100%.

[0126] 6. Prepare the glaze slurry: Weigh out 80kg of glaze ore, 20kg of glaze ash, 1kg of potassium feldspar, 1kg of limestone, 1kg of low-iron kaolin, and 5kg of iron oxide. Add all the above components to 70kg of water and then ball mill them to make a fine glaze slurry.

[0127] The glaze ash was prepared according to the method in Example 1.

[0128] The glaze ore is sourced from Jianyang District, Nanping City, Fujian Province. The uranium ore contains 15% ferric oxide, 11% calcium oxide, 40% silicon dioxide, and 18% aluminum oxide.

[0129] 7. Glazing Immerse the furnace body in the glaze, let it stand for 10-20 seconds, and then remove it.

[0130] 8. Roasting The glazed furnace body is placed into the firing kiln and fired at 900℃ for 4 hours. Then, it is fired at 1300℃ for 44 hours under a reducing atmosphere. Wet materials are added to the kiln to ensure firing under a reducing atmosphere.

[0131] 9. Cooling and unloading from the kiln: After firing, the cooling rate is controlled to room temperature before being removed from the kiln. The cooling rate curve is as follows: cooling to 950℃ at 0.5℃ / min, and then cooling to room temperature at 8℃ / min.

[0132] 10. Finished product inspection: After the products are removed from the kiln, the glazed products are inspected to observe their deformation and cracking. The deformation and cracking rate is calculated as follows: Deformation and cracking rate = Number of deformed and cracked products / Total number of products × 100%.

[0133] Example 3 Embodiment 3 provides a ceramic charcoal stove ring, wherein the ring is a circular structure with an inner diameter of 8 mm, an outer diameter of 18 mm, and a thickness of 1 mm. Its preparation method is as follows: 1. Prepare the clay Weigh out 60 kg of red soil, 10 kg of iron-rich kaolin and 20 kg of mullite respectively, and mix them to obtain the body soil.

[0134] The red clay was purchased from Lin Jian'an Clay Factory in Jianyang City, with an iron content of 8.5%, a silicon dioxide content of 68%, and an aluminum oxide content of 20%. The iron-rich kaolin was purchased from Jianyang City Shuiji Weiwei Clay Factory, which contains 80 wt% kaolinite and 8% iron.

[0135] The mullite was purchased from Jianyang Chen Xiaohua Clay Factory, and it contains 80% aluminum oxide and 18% silicon dioxide.

[0136] 2. Practicing clay: The clay is washed with water, sieved, and then screened through an 80-mesh sieve to remove impurities. It is then sun-dried for 20 days until the moisture content reaches 20-30%.

[0137] Then, the clay is repeatedly kneaded, squeezed, and expelled to remove air, making the clay structure uniform and dense. The kneading and squeezing are repeated more than 300 times.

[0138] 3. Throwing: The clay is manually pulled into the required shape of the furnace ring on a rotating wheel and then allowed to air dry naturally.

[0139] 4. Trimming: After the furnace ring is naturally air-dried to a moisture content of 8-15%, it is finely trimmed with a trimming knife to remove excess parts, correct the shape, and polish the surface to make the furnace body lines smooth, the thickness uniform, and the appearance beautiful.

[0140] 5. Roasting: The shaped furnace ring blank was fired at 900℃ for 8 hours to obtain the raw blank layer of the furnace body. The deformation and cracking of the product were observed, the deformation and cracking of the raw blank layer products were counted, and the deformation and cracking rate of the raw blank layer products was calculated. The deformation and cracking rate = number of deformation and cracks / total number of products × 100%.

[0141] 6. Prepare the glaze slurry: Weigh out 60kg of glaze ore, 10kg of glaze ash, 5kg of potassium feldspar, 5kg of limestone, 5kg of low-iron kaolin, and 10kg of iron oxide. Add all the above components to 70kg of water and then ball mill them to make a fine glaze slurry.

[0142] The glaze ash was prepared according to the method in Example 1.

[0143] The glaze ore is sourced from Jianyang District, Nanping City, Fujian Province, and contains 10wt% ferric oxide, 6wt% calcium oxide, 60wt% silicon dioxide, and 20wt% aluminum oxide.

[0144] 7. Glazing Immerse the furnace body in the glaze, let it stand for 10-20 seconds, and then remove it.

[0145] 8. Roasting The glazed furnace body is loaded into the firing kiln and fired at 800℃ for 5 hours. Then, it is fired at 1200℃ for 50 hours under a reducing atmosphere. Wet materials are added into the kiln to ensure firing under a reducing atmosphere.

[0146] 9. Cooling and unloading from the kiln: After calcination, the cooling rate is controlled to room temperature before the product is removed from the kiln. The cooling rate curve is as follows: cooling to 1050℃ at 2℃ / min, and then cooling to room temperature at 12℃ / min.

[0147] 10. Finished product inspection: After the products are removed from the kiln, the glazed products are inspected to observe their deformation and cracking. The deformation and cracking rate is calculated as follows: Deformation and cracking rate = Number of deformed and cracked products / Total number of products × 100%.

[0148] Example 4 Embodiment 4 provides a ceramic charcoal furnace chamber, wherein the chamber is a frustum shape with openings at both ends, the upper opening diameter is 8.5 cm, the lower opening diameter is 10 cm, the chamber wall thickness is 1 cm, and the chamber height is 11 cm. Its preparation method is as follows: 1. Prepare the clay Weigh out 45 kg of red soil, 17 kg of iron-rich kaolin and 13 kg of mullite respectively, and mix them to obtain the body soil.

[0149] The red clay was purchased from Lin Jian'an Clay Factory in Jianyang City, with an iron content of 8.5%, a silicon dioxide content of 68%, and an aluminum oxide content of 20%. The iron-rich kaolin was purchased from Weiwei Clay Factory in Shuiji, Jianyang City. It contains 80 wt% kaolinite and 8% iron. The mullite was purchased from Jianyang Chen Xiaohua Clay Factory, and it contains 80% aluminum oxide and 18% silicon dioxide.

[0150] 2. Practicing clay: The clay is washed with water, sieved, and then screened through an 80-mesh sieve to remove impurities. It is then sun-dried for 20 days until the moisture content reaches 20-30%.

[0151] Then, the clay is repeatedly kneaded, squeezed, and expelled to remove air, making the clay structure uniform and dense. The kneading and squeezing are repeated more than 300 times.

[0152] 3. Throwing: The clay is manually pulled into the required shape of the furnace body on a rotating wheel and then allowed to air dry naturally.

[0153] 4. Trimming: After the furnace body is naturally air-dried to a moisture content of 8-15%, it is finely repaired with a repair knife to remove excess parts, correct the shape, and polish the surface to make the furnace body lines smooth, the thickness uniform, and the appearance beautiful.

[0154] 5. Roasting: The shaped furnace body blanks are placed into the kiln and fired at 800℃ for 8 hours. After cooling, the blanks are removed from the kiln to obtain the unglazed layer of the furnace body. The deformation and cracking of the unglazed products are observed, and the deformation and cracking rate of the unglazed layer is calculated. The deformation and cracking rate is calculated as follows: (Number of deformation and cracks / Total number of cracks) × 100%.

[0155] Comparative Example 1 The difference between Comparative Example 1 and Example 4 is that in the mud preparation step 1, low-iron kaolin is used instead of high-iron kaolin.

[0156] Among them, the kaolinite content in the low-iron kaolin is 80wt%, and the iron content is 1.5wt%.

[0157] Comparative Example 2 The difference between Comparative Example 1 and Example 4 is that Chaozhou red clay was used instead of red soil in step 1, the clay preparation step. The Chaozhou red clay contained 6% iron, 42% silicon dioxide, and 17% aluminum oxide.

[0158] Comparative Example 3 The difference from Example 1 is that no glaze ash is added when preparing the glaze slurry in Comparative Example 3.

[0159] Experimental Example The ceramic products prepared in the above examples and comparative examples were subjected to thermal shock resistance tests according to the following methods. The experimental results of thermal shock resistance, deformation cracking rate and glaze uniformity are shown in Table 1.

[0160] 1) Thermal shock resistance Take 5 samples, heat them to 200℃, keep them at that temperature for 10 minutes, and then immerse them in running water at 20℃ for 5 minutes. Observe whether cracks occur, count the number of samples that crack, and calculate the sample crack rate, i.e., sample crack rate = number of samples that crack / total number of samples × 100%.

[0161] Table 1 Test Results Thermal shock resistance (crack rate) of raw blank products Thermal shock resistance (crack rate) of glazed products Deformation and cracking rate of raw blank products Deformation and cracking rate of glazed products Glaze uniformity Example 1 0 0 2% 2% Even glaze Example 2 0 0 15% 10% Even glaze Example 3 0 0 5% 8% Even glaze Example 4 0 26% Comparative Example 1 80% 40% Comparative Example 2 80% 45% Comparative Example 3 0 0 2% 15% The glaze is uneven and has color spots. As shown in Table 1, both the unglazed ceramic products and the glazed ceramic products obtained in this application have high thermal shock resistance. The deformation and cracking rate of the unglazed products is less than 30%, and the cracking rate of the glazed products is less than or equal to 10%, with uniform and beautiful glaze color. Furthermore, the deformation and cracking rate of the unglazed products obtained in Examples 1 and 3 is less than or equal to 5%, and the deformation and cracking rate of the glazed products is less than or equal to 8%. Compared with Example 4, Comparative Example 1 uses low-iron kaolin, which significantly reduces thermal shock resistance and increases the deformation and cracking rate of the product; compared with Example 4, Comparative Example 1 uses Chaozhou red clay instead of red clay, which significantly reduces thermal shock resistance and also increases the deformation and cracking rate of the product; compared with Example 1, Comparative Example 3 does not add glaze ash to the glaze slurry, resulting in a significant increase in the deformation and cracking rate of the glazed product, and the glaze color is uneven with color spots.

[0162] In summary, this application utilizes a scientifically proportioned combination of red clay, iron-rich kaolin, and mullite containing specific components to improve the high-temperature resistance of ceramic products while simultaneously enhancing their processing performance, making them less prone to deformation and cracking. Furthermore, the multi-layered composite ceramic products of this application incorporate a glaze layer on top of the unglazed body, further improving the hardness and refractoriness of the ceramic products, and resulting in a uniform and aesthetically pleasing glaze surface.

[0163] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

[0164] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0165] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A clay composition for preparing ceramic products, characterized in that, It comprises the following components in parts by weight: The laterite contains 40-60 parts of iron, 7-11 wt% iron, 65-70 wt% silicon dioxide, and 19-23 wt% aluminum oxide. 10-20 parts of iron-rich kaolin, wherein the iron content in the iron-rich kaolin is 7-10 wt%; and 10-20 parts of mullite, wherein the content of aluminum oxide in the mullite is 75-85 wt%.

2. The mud composition according to claim 1, characterized in that, The composition comprises the following components in parts by weight: 50-60 parts of laterite, 10-15 parts of iron-rich kaolinite, and 15-20 parts of mullite.

3. The mud composition according to claim 1 or 2, characterized in that, The laterite contains 8.5–10.5 wt% iron, 65–68 wt% silicon dioxide, and 19–20 wt% aluminum oxide. And / or, the iron content in the iron-rich kaolin is 8-10 wt%; And / or, the silica content in the mullite is 10-23 wt%, preferably 18-23 wt%.

4. A ceramic product, characterized in that, It is prepared by steps including shaping and firing the clay composition according to any one of claims 1-3. Preferably, the ceramic product includes a charcoal furnace body, a charcoal furnace ring, or a charcoal furnace chamber.

5. The method for preparing the ceramic product according to claim 4, characterized in that, Includes the following steps: S11. Mix the clay composition with water to prepare a raw material for the green body; S12. The raw material is pulled and trimmed to produce ceramic product blanks; S13. Ceramic products are obtained by firing ceramic blanks.

6. A multi-layer composite ceramic product, characterized in that, It includes: A raw material layer, which is made by using the clay composition described in any one of claims 1-3 as a raw material; The glaze layer covering the surface of the body layer is made by using a glaze composition as raw material, wherein the glaze composition comprises the following components in parts by weight: 60-80 parts glaze ore, 10-20 parts glaze ash, 1-5 parts potassium feldspar, 1-5 parts limestone, 1-5 parts kaolinite, and 5-10 parts iron oxide red.

7. The multilayer composite ceramic product according to claim 6, characterized in that, The glaze composition comprises the following components in parts by weight: 60-70 parts glaze ore, 10-15 parts glaze ash, 3-5 parts potassium feldspar, 3-5 parts limestone, 3-5 parts kaolinite, and 7-10 parts iron oxide red. Preferably, the glaze ore comprises 7-10 wt% ferric oxide, 5-8 wt% calcium oxide, 40-60 wt% silicon dioxide and 15-20 wt% aluminum oxide; More preferably, the glaze ash is prepared by a method comprising: S241. Obtain wolfsbane ash by burning it in an oxygen-deficient environment; S242. Wet ash paste is obtained by dissolving and separating wolfberry ash; S243. The wet ash paste is dried and ground to obtain glaze ash.

8. The method for preparing the multilayer composite ceramic product according to claim 6 or 7, characterized in that, It includes the following steps: S21. Mix the clay composition with water to prepare a raw material for the green body; S22. The raw material for the billet is pulled and trimmed to form a billet; S23. The green body is first fired to obtain a green body layer; S24. Mix the glaze composition with water to prepare a glaze slurry; S25. Apply the glaze slurry obtained in step S24 to the surface of the green body layer obtained in step S23, and perform a second firing to obtain the multi-layer composite ceramic product.

9. The preparation method according to claim 8, characterized in that, The second calcination in step S25 includes the following steps: first, heating to 800-1000℃ and holding for 3-5 hours, then heating to 1250-1300℃ and holding for 40-50 hours in a reducing atmosphere.

10. The preparation method according to claim 9, characterized in that, After the roasting in step S25, a cooling step is also included, wherein the cooling curve is as follows: cooling to 950-1050℃ at 0.5-2℃ / min, and then cooling to room temperature at 8-12℃ / min.