Ceramic with ring-shaped mottled enamel surface and process for its production

Abstract

The present application relates to the field of ceramic and its preparation process, in particular to a kind of annular spot glaze ceramic and its preparation process, annular spot glaze ceramic includes body and glaze layer, glaze layer from bottom to top includes foamed kaolin, ground glaze and face glaze in turn, and annular spot is distributed on glaze layer.In the process of glazing, the bubble-forming particles in foamed kaolin decompose to form gas, the gas rises to form bubble glaze, and the glaze bubble breaks through the glaze surface to form glaze pit, the substances with good fluidity such as ceramic mother liquor in ground glaze flow towards the glaze pit, and then lead to the enrichment of iron oxide around the glaze pit, forming a red-brown glaze ring with a color darker than that of the ground glaze, and a light yellow circular spot is formed in the center of the glaze ring, i.e., forming annular spot;In the process of re-firing, the face glaze flows towards the glaze pit and fills the glaze pit, and radial cracks are formed around the glaze ring during the cooling process.

Description

Technical Field

[0001] The invention relates to the field of ceramics and a preparation process thereof, and in particular to annular spotted glazed ceramics and a preparation process thereof. Background Art

[0002] From porcelain's original white to its cyan and then to speckled glazes, the development of each color reflects the profound changes in Chinese porcelain culture. For example, the celadon dotwork of the Yue Kiln during the Jin Dynasty, the underglaze painting of the Changsha Kiln during the Tang Dynasty, Tang Sancai (three-color glaze), the shadow blue with brown spots of the Song Dynasty, the purple spots of the Jun Kiln during the Yuan Dynasty, the flying green porcelain of the Longquan Kiln, and the tiger-skin tri-color glaze of the Qing Dynasty. The Cizhou Kiln of the Song and Jin Dynasties used large patches of color on black glaze, known as "rust spots." The Longquan Kiln of the Yuan Dynasty invented brown spots to decorate celadon, known as "flying green" in Japan. Existing speckled glazes tend to have a relatively simple pattern of spots, often appearing on the glaze surface in a single color. The spots vary in size and often have an irregular shape. This project was created to innovate on traditional speckled glazes. Summary of the Invention

[0003] An object of the present invention is to solve at least the above-mentioned problems by means of annular spotted glaze ceramics and a process for preparing the same.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is as follows: annular spotted glazed ceramics, including a body and a glaze layer, the glaze layer including foamed makeup soil, base glaze and surface glaze from bottom to top, and annular spots are distributed on the glaze layer.

[0005] Preferably, the raw materials of the foaming cosmetic clay include the following components in parts by weight: 10-12 parts of foaming particles, 40-50 parts of kaolin, 15-18 parts of talc, and 6-8 parts of diatomaceous earth.

[0006] Preferably, the particle size of the foaming particles is 1.2-1.5 mm.

[0007] Preferably, the foaming particles include a core material and a skin material covering the surface of the core material. The raw material of the core material is calcite particles. The raw material of the skin material includes the following components in parts by weight: 50-55 parts of quartz stone powder and 50-55 parts of kaolin.

[0008] Preferably, the raw materials of the base glaze include the following components in parts by weight: 20-22 parts of calcined color clinker, 20-25 parts of feldspar, 30-33 parts of kaolin, 10-15 parts of quartz, 7-9 parts of ceramic mother liquor, 4-6 parts of sodium carbonate, and 4-6 parts of potassium hydroxide.

[0009] Preferably, the raw materials of the calcined color clinker include the following components in parts by weight: 15-17 parts of industrial iron oxide, 10-12 parts of quartz, 25-28 parts of kaolin, 10-12 parts of feldspar, and 5-10 parts of talc.

[0010] Preferably, the raw materials of the ceramic mother liquor include the following components in parts by weight: 30-40 parts of waste white porcelain powder, 6-8 parts of sodium chloride, 10-12 parts of kaolin, and 20-30 parts of water.

[0011] Preferably, the raw materials of the glaze include the following components in parts by weight: 30-35 parts of feldspar, 20-23 parts of kaolin, 10-15 parts of quartz, 5-8 parts of talc, 5-6 parts of limestone, and 5-6 parts of wollastonite.

[0012] According to the above-mentioned preparation process of the annular spotted glazed ceramic, the following steps are included:

[0013] Step a, forming a green body and drying it;

[0014] Step b, applying a layer of foaming clay on the surface of the green body and drying;

[0015] Step c, applying base glaze and top glaze on the foaming makeup soil in sequence;

[0016] Step d, glaze firing in a kiln at a temperature of 1100-1150 degrees Celsius;

[0017] Step e: Re-firing in a kiln to obtain annular spotted glazed ceramics.

[0018] Preferably, in step d, the re-firing comprises the following steps: cooling to 750-800 degrees Celsius and keeping warm for 4-5 hours, then heating to 1020-1050 degrees Celsius and keeping warm for 1-2 hours, and finally cooling and removing from the furnace to obtain annular spotted glazed ceramics.

[0019] From the above description, it can be seen that the ring-shaped spotted glaze ceramics provided by the present invention and the preparation process thereof have the following beneficial effects: during the glaze firing process, the bubble particles in the foaming makeup soil decompose to form gas, the gas rises to form bubble glaze, and the glaze bubbles break through the glaze surface to form glaze pits. The ceramic mother liquor and other substances with good fluidity in the bottom glaze fill the glaze pits, which leads to the enrichment of iron oxide around the glaze pits, forming a reddish-brown glaze ring that is darker than the bottom glaze, and a light yellow circular spot is formed in the center of the glaze ring, that is, a ring-shaped spot is formed; during the re-firing process, the surface glaze flows toward the glaze pit and fills the glaze pit. The re-firing temperature is low, so that the ring-shaped spot structure remains stable. During the final cooling process, due to the enrichment of iron oxide in the glaze ring, it has different fluidity and shrinkage rates compared with other parts of the glaze surface. Radial cracks are formed around the glaze ring during the cooling process. DETAILED DESCRIPTION

[0020] The present invention is further described below through specific embodiments.

[0021] In order to make the technical means, creative features, objectives and effects achieved by the present invention easier to understand, the present invention is further described below in conjunction with specific implementation methods.

[0022] The present invention discloses a ceramic with annular spots on a glaze surface, comprising a body and a glaze layer. The glaze layer comprises, from bottom to top, a foaming base, a base glaze, and a top glaze, with annular spots distributed throughout the glaze layer. After firing, the glaze layer exhibits a yellowish-brown base color, with the annular spots distributed throughout. The annular spots have a reddish-brown glaze ring with a light yellow circular spot in the center.

[0023] The raw materials of the foaming makeup soil are calculated by weight and include the following components: 10-12 parts of foaming particles, 40-50 parts of kaolin, 15-18 parts of talc, and 6-8 parts of diatomaceous earth. If the particle size of the foaming component in the glaze is too small, bubbles cannot gather during the glaze firing process, and the bubbles will be quickly filled by the flowing glaze, and no glaze pits can be formed. The foaming makeup soil of the present invention contains large-particle-sized foaming particles. During the glaze firing process, the foaming particles decompose and release gas. Since the particle size of the foaming particles is large, the released gas is concentrated and easily gathered to form large glaze bubbles. The glaze bubbles then break through the glaze surface to form large glaze pits. Compared with glaze pits formed by small glaze bubbles, large glaze pits take longer to be filled and require more glaze to fill. Therefore, filling large glaze pits will cause more active activity of high-fluidity components in the surrounding glaze, thereby changing the component ratio around the glaze bubbles.

[0024] The particle size of the foaming particles is 1.2-1.5mm. Large-sized foaming particles can produce larger glaze bubbles. The other components of the foaming soil are ground to 100-150 mesh, and the components of the base glaze and top glaze are ground to 200-300 mesh. The fineness of the other glaze components other than the foaming particles is relatively high. Therefore, the bubbles generated by the other components of the foaming soil, the base glaze and the top glaze themselves are small and easier to expel and fill quickly.

[0025] The foaming particles include a core material and a skin material covering the surface of the core material. The raw material of the core material is calcite particles. The raw materials of the skin material include the following components in parts by weight: 50-55 parts of quartz stone powder and 50-55 parts of kaolin. The core material of the bubble-forming particles is large, light yellow granular calcite. Calcite is a calcium carbonate mineral with good fluidity and dispersibility. It decomposes during the glaze firing process to generate carbon dioxide. Due to the large particle size of calcite, it breaks through during the glaze firing process to form large glaze bubbles, which in turn form pits on the glaze surface. The core material is covered with a layer of skin material, and the blank contains a large proportion of quartz powder. The fluidity of quartz powder is poor. During the glaze firing process, it can delay the decomposition and release of gas in the core material. Therefore, compared with other components in the glaze that can cause bubbles, the bubble-forming particles release the gas more slowly. In addition, other components in the glaze that can cause bubbles are in the glaze surface and have finer particles, while the bubble-forming particles are located in the foaming makeup soil under the glaze surface and are deeper. Therefore, the gas release rate of the foaming components in the glaze surface is faster than that of the bubble-forming particles in the foaming makeup soil, and will not interfere with the glaze bubble formation of the bubble-forming particles. The preparation process of the foamed particles is as follows: calcite particles with a particle size of 0.8-1.0 mm are soaked in a slurry made by adding water to the raw material components of the skin material, taken out and dried, and the process can be repeated several times to ensure that the blank fully covers the core material.

[0026] The raw materials of the base glaze include the following components in parts by weight: 20-22 parts of calcined color clinker, 20-25 parts of feldspar, 30-33 parts of kaolin, 10-15 parts of quartz, 7-9 parts of ceramic mother liquor, 4-6 parts of sodium carbonate and 4-6 parts of potassium hydroxide. Among the components of the bottom glaze, ceramic mother liquor, sodium carbonate, potassium hydroxide, feldspar, etc. are all substances with good fluidity, while industrial iron oxide and quartz have relatively poor fluidity. Therefore, during the glaze firing process, after the glaze bubble rises to form a glaze pit, the high-fluidity components in the bottom glaze and the surface glaze are more likely to flow toward the glaze pit, while the calcined color clinker is rich in industrial iron oxide, and industrial iron oxide and quartz are less likely to flow toward the glaze pit. In the process of the fluid substances flowing toward the glaze pit, the proportion of high-fluidity components around the glaze pit decreases significantly, and the proportion of iron oxide increases significantly, that is, iron oxide is enriched around the glaze pit, forming a glaze ring that is darker than the bottom glaze. The bottom glaze itself is yellowish brown, while the glaze ring enriched with iron oxide is reddish brown. The center of the glaze ring is filled with a mixture of surface glaze, high-fluidity components in the bottom glaze and the decomposition products of the bubble particles brought up during the rising process of the glaze bubble, thus forming a light yellow circular spot.

[0027] The raw materials for calcined color clinker, measured in parts by weight, include the following: 15-17 parts industrial iron oxide, 10-12 parts quartz, 25-28 parts kaolin, 10-12 parts feldspar, and 5-10 parts talc. The calcined clinker is produced by mixing, firing, cooling, crushing, grinding, and screening the raw materials. Because the clinker is calcined first, it exhibits excellent high-temperature stability. Furthermore, it is rich in iron oxide, resulting in a high melting point and relatively poor fluidity when used as an additive in glazes.

[0028] The raw materials for the ceramic mother liquor, measured by weight, include the following: 30-40 parts of waste white porcelain powder, 6-8 parts of sodium chloride, 10-12 parts of kaolin, and 20-30 parts of water. The ceramic mother liquor is a mixture of waste white porcelain powder, salt water, and kaolin. This mixture contains a large number of oxides and silicates, which melt at high temperatures to form compounds of elements such as aluminum, silicon, and sodium. Adding an appropriate amount of ceramic mother liquor to the glaze promotes flow and wetting, thereby providing sufficient high-flowing components for the base glaze.

[0029] The raw materials for the top glaze, measured by weight, include the following: 30-35 parts feldspar, 20-23 parts kaolin, 10-15 parts quartz, 5-8 parts talc, 5-6 parts limestone, and 5-6 parts wollastonite. The top glaze is transparent, and wollastonite contains high levels of calcium (Ca) and silicon (Si). Both limestone and wollastonite can increase the glaze's meltability and improve its fluidity. Feldspar also serves to lower the glaze's melting point, increasing its fluidity and hardness. This results in excellent overall fluidity for the top glaze, allowing it to quickly fill glaze pits during firing.

[0030] The preparation process of spotted glazed ceramics includes the following steps:

[0031] Step a, forming a green body and drying it;

[0032] Step b, applying a layer of foaming clay on the surface of the green body and drying;

[0033] Step c, applying base glaze and top glaze on the foaming makeup soil in sequence;

[0034] Step d: Put the glaze into the kiln for firing at a temperature of 1100-1150 degrees Celsius. During the firing process, the bubble particles in the foaming makeup soil decompose to form gas, which rises to form bubble glaze. The glaze bubbles break through the glaze surface to form glaze pits. The ceramic mother liquor and other substances with good fluidity in the base glaze fill the glaze pits, which leads to the enrichment of iron oxide around the glaze pits, forming a reddish-brown glaze ring that is darker than the base glaze color, and a light yellow circular spot is formed in the center of the glaze ring, that is, a ring-shaped spot is formed.

[0035] Step e: Re-firing in a kiln to obtain annular spotted glazed ceramics.

[0036] In step d, re-firing includes the following steps: cooling to 750-800 degrees Celsius and holding for 4-5 hours, then heating to 1020-1050 degrees Celsius and holding for 1-2 hours, and finally cooling and removing from the furnace to produce ring-shaped spotted glazed ceramics. Glaze pits and glaze rings are formed during the glaze firing process. Without removing from the furnace, the temperature is first lowered to 750-800 degrees Celsius and held for a period of time to allow the ring-shaped spots to fully crystallize and form. The temperature is then raised again and re-fired. During the re-firing process, the top glaze flows toward the glaze pits and fills them. Therefore, the glaze surface after firing is relatively smooth, with no special protrusions near the spots. The re-firing temperature is low, which keeps the ring-shaped spot structure stable. During the final cooling process, due to the enrichment of iron oxide in the glaze ring, it has different fluidity and shrinkage compared to other parts of the glaze surface, and radial cracks form around the glaze ring after cooling.

[0037] The above are only some specific implementation methods of the present invention, but the design concept of the present invention is not limited to this. Any non-substantial changes to the present invention using this concept shall be deemed as an infringement of the protection scope of the present invention.

Claims

1. Annular spotted glazed ceramics, characterized by: The invention comprises a body and a glaze layer, wherein the glaze layer comprises, from bottom to top, a foaming makeup soil, a base glaze and a top glaze, wherein the glaze layer is provided with annular spots, and the raw materials of the foaming makeup soil are calculated by weight as follows: 10-12 parts of foaming particles, 40-50 parts of kaolin, 15-18 parts of talc, and 6-8 parts of diatomaceous earth, wherein the particle size of the foaming particles is 1.2-1.5 mm, and the raw materials of the base glaze are calculated by weight as follows: 20-22 parts of calcined color clinker, 20-25 parts of feldspar, 3 0-33 parts, quartz 10-15 parts, ceramic mother liquor 7-9 parts, sodium carbonate 4-6 parts, potassium hydroxide 4-6 parts, the raw materials of the calcined color clinker, calculated in parts by weight, include the following components: industrial iron oxide 15-17 parts, quartz 10-12 parts, kaolin 25-28 parts, feldspar 10-12 parts, talc 5-10 parts, the raw materials of the ceramic mother liquor, calculated in parts by weight, include the following components: waste white porcelain powder 30-40 parts, sodium chloride 6-8 parts, kaolin 10-12 parts, water 20-30 parts.

2. The annular spotted glazed ceramic according to claim 1, characterized in that: The foaming particles include a core material and a skin material covering the surface of the core material. The raw material of the core material is calcite particles. The raw material of the skin material includes the following components in parts by weight: 50-55 parts of quartz stone powder and 50-55 parts of kaolin.

3. The annular spotted glazed ceramic according to claim 1, characterized in that: The raw materials of the glaze include the following components in parts by weight: 30-35 parts of feldspar, 20-23 parts of kaolin, 10-15 parts of quartz, 5-8 parts of talc, 5-6 parts of limestone, and 5-6 parts of wollastonite.

4. The preparation process of the annular spotted glazed ceramic according to any one of claims 1 to 3, characterized in that: The steps include: Step a, forming a green body and drying it; Step b, applying a layer of foaming clay on the surface of the green body and drying; Step c, applying base glaze and top glaze on the foaming makeup soil in sequence; Step d, glaze firing in a kiln at a temperature of 1100-1150 degrees Celsius; Step e: re-firing in a kiln to obtain annular spotted glazed ceramics.

5. The process for preparing the annular spotted glazed ceramic according to claim 4, characterized in that: In the step e, the re-firing comprises the following steps: cooling to 750-800 degrees Celsius and keeping the temperature for 4-5 hours, then heating to 1020-1050 degrees Celsius and keeping the temperature for 1-2 hours, and finally cooling and removing from the furnace to obtain annular spotted glazed ceramics.