Ceramic raw iron red glaze and preparation method thereof

Abstract

The application provides a ceramic raw material iron red glaze and a preparation method thereof, and belongs to the technical field of inorganic material preparation. The ceramic raw material iron red glaze comprises the following components in parts by weight: 15.5-17.5 parts of potash feldspar, 22.5-23.5 parts of soda feldspar, 7-8 parts of white kaolin in Panxi region, 14-18 parts of quartz, 6-7 parts of calcite, 10-12 parts of calcined talc, 10-12 parts of bone powder and 14-16 parts of vanadium titanium magnetite. The bone powder comprises the following components in percentage by mass: 0.85-2.35% of SiO2, 0.36-0.74% of Al2O3, 44.56-46.75% of CaO, 0.76-1.50% of MgO, 0.03-0.12% of K2O, 0.53-0.86% of Na2O, 0.12-0.14% of Fe2O3, 0.03-0.05% of TiO2, 36.76-48.79% of P2O5, and the balance of inevitable impurities. The iron red glaze provided by the application is bright and dynamic, rich in changes, and has yellow silk-like flow lines interspersed in the sheet of fire red color, which is colorful and makes the whole vessel have the quality of being rare, noble and dignified. The application is mainly used for tea bowls, cups and other tea utensils, and can also be used for bowls, plates, toys, ink stones and other living utensils.

Description

Technical Field

[0001] This invention belongs to the field of inorganic material preparation technology, specifically relating to ceramic raw material iron oxide red glaze and its preparation method. Background Technology

[0002] Iron-red glaze is an iron-crystal glaze ranging from vermilion to deep red, also known as iron-red flower glaze or persimmon-red glaze, and commonly called red-orange glaze. The characteristic of iron-red glaze is that it covers the entire ceramic ware with a bright and generous red color, resembling a red flower blooming in the night, giving a stunning impression. Under sunlight, it reflects a beautiful moment of red light colliding with natural light. In the diverse history of porcelain, iron-red glaze is a unique presence. Currently, domestic research on iron-red glaze is still in the antique imitation stage, and innovation is not yet possible. Existing domestic research on iron-red glaze suffers from the following problems: it focuses more on the design of the iron-red glaze body shape and appearance, with a lack of research on the formula and process of iron-red glaze; in addition, iron-red glaze is affected by many factors during firing, has poor stability, complex reduction processes, and low yield; the firing temperature is high, resulting in high cost and energy consumption; the oxidation degree of iron-based elements in the glaze is difficult to control; and the thickness of the glaze layer is also an important factor affecting the red color. These problems limit the development and application of iron-red glaze-related technologies and products. Summary of the Invention

[0003] To address the aforementioned technical problems, this invention provides a ceramic raw material iron-red glaze and its preparation method. The iron-red glaze provided by this invention has a bright and vibrant color, rich in variation, with yellow thread-like flow lines interspersed within the large areas of fiery red, creating a dazzling and colorful effect that gives the entire vessel a rare, noble, and dignified texture.

[0004] The technical solution of the present invention is as follows:

[0005] The first objective of this invention is to provide a ceramic raw material iron oxide red glaze, the raw materials of which include the following components in parts by weight: 15.5-17.5 parts potassium feldspar, 22.5-23.5 parts sodium feldspar, 7-8 parts white kaolin from the Panxi region, 14-18 parts quartz, 6-7 parts calcite, 10-12 parts calcined talc, 10-12 parts bone meal, and 14-16 parts vanadium-titanium magnetite.

[0006] The bone powder comprises, by mass percentage: SiO2: 0.85–2.35%, Al2O3: 0.36–0.74%, CaO: 44.56–46.75%, MgO: 0.76–1.50%, K2O: 0.03–0.12%, Na2O: 0.53–0.86%, Fe2O3: 0.12–0.14%, TiO2: 0.03–0.05%, P2O5: 36.76–48.79%, with the balance being unavoidable impurities.

[0007] The bone powder of this invention is obtained by grinding pure bovine bone into powder after degreasing and desalting, and then heat-treating it at 1000-1200℃.

[0008] In one specific embodiment, there are 15.5 parts potassium feldspar, 22.5 parts sodium feldspar, 8 parts white kaolin from the Panxi region, 14-18 parts quartz, 6 parts calcite, 10 parts calcined talc, 10 parts bone meal, and 14-16 parts vanadium-titanium magnetite.

[0009] In one specific embodiment, the vanadium-titanium magnetite comprises, by mass percentage: SiO2: 6.88–7.07%, Al2O3: 1.65–1.80%, CaO: 1.96–2.20%, MgO: 1.67–2.00%, K2O: 4.55–4.72%, Na2O: 4.82–5.13%, TiO2: 6.03–6.79%, Fe3O4: 62.15–63.01%, loss on ignition: 10.26–7.28%, with the balance being unavoidable impurities.

[0010] In one specific embodiment, the iron oxide red glaze has a color difference of L: 22.27~27.13, a: 16.56~18.47, b: 12.93~13.65, and a gloss of 14.9~60; it is resistant to thermal shock and can withstand three rapid cooling cycles from 200℃ to 20℃ without cracking.

[0011] The second objective of this invention is to provide a method for preparing the above-mentioned ceramic raw material iron oxide red glaze, comprising the following steps:

[0012] (1) Weighing: Weigh each raw material according to its components;

[0013] (2) Ball milling and sieving: The raw materials weighed in step (1) are ball milled to obtain glaze slurry, and then the glaze slurry is sieved through a 250-mesh standard sieve.

[0014] (3) Aging: Seal the glaze slurry after sieving in step (2) and place it in a dry and cool place to age for more than 24 hours;

[0015] (4) Glazing and drying: Remove the upper clear liquid from the glaze slurry after aging in step (3), and maintain the specific gravity of the glaze slurry at 1.65-1.75 g / cm³. 3 After stirring evenly, the glaze is applied to the surface of the ceramic body, and then the glazed ceramic body is dried.

[0016] (5) Firing: The ceramic blank dried in step (4) is heated from room temperature to 960-980℃ at a heating rate of 3.8-7.6℃ / min; then heated to 1120-1130℃ at a heating rate of 1.1-1.2℃ / min; then heated to 1200-1210℃ at a heating rate of 2.0-4.0℃ / min; finally heated to 1240-1250℃ at a heating rate of 0.4-1.0℃ / min and held at that temperature for 20-30 minutes; finally, heating is stopped and the ceramic blank is cooled to room temperature in the furnace to obtain the iron red glaze product.

[0017] Alternatively, the ceramic blank dried in step (4) can be heated from room temperature to 960-980℃ at a heating rate of 3.8-7.6℃ / min; then heated to 1120-1130℃ at a heating rate of 1.1-1.2℃ / min; then heated to 1240-1250℃ at a heating rate of 1.0-1.2℃ / min and held at that temperature for 20-30 minutes; finally, heating can be stopped and the blank can be cooled to room temperature in the furnace to obtain the iron red glaze product.

[0018] In this invention, the purpose of aging is to promote the oxidation, hydrolysis and decay of residual organic matter in the clay, generate humic acid, naturally eliminate air bubbles and stress in the clay, ensure uniform moisture content, enhance plasticity, and improve molding quality.

[0019] In one specific embodiment, in step (2), the mass ratio of raw material:ball:water in the ball mill is controlled to be 1:2:0.8 to 1:2.5:1, and the ball milling time is 8 to 10 minutes.

[0020] In one specific implementation, in step (2), the sample is passed through a 250-mesh standard sieve, and the residue on the sieve is less than 0.5%.

[0021] In one specific embodiment, in step (4), glazing is carried out by immersion glazing. Each time the ceramic body is immersed in the glaze slurry and then taken out, the glaze on the surface of the body is dried and then immersed in glaze again, so that the thickness of the glaze layer is maintained between 1 and 2 mm.

[0022] In one specific embodiment, the glazed ceramic body is dried by natural air drying or by placing it in a drying oven at 50-80°C for 3-5 hours.

[0023] In one specific embodiment, in step (4), the surface of the ceramic body is cleaned and water is added before glazing. The ceramic body is glazed after it has dried.

[0024] After the ceramic body is formed from clay, the surface often has fine pores and small tool marks due to hand-throwing or trimming, and is also covered with clay powder and dust. If glaze is applied directly, the firing process can easily lead to glaze defects such as pitting, pinholes, and glaze shrinkage. Adding water can, on the one hand, make the surface of the body smoother, eliminate trimming marks, and remove clay chips, dust, and other impurities adhering to the surface, reducing the possibility of glaze defects; on the other hand, adding water can also reveal hidden pores and "dead clay" (hard clumps of clay mixed in with wet clay that were not removed during kneading), thus improving the yield rate.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0026] 1. The iron-red glaze provided by this invention is entirely flame-red and belongs to a type of phase-split glaze. Unlike other phase-split glazes, the iron-red glaze has a surface glaze thickness of 1-2 mm, with patches of fiery red interspersed with yellow thread-like flow lines, creating a vibrant and colorful effect. It is mainly used for tea bowls, cups, and other tea ceremony utensils, but can also be used for bottles, bowls, plates, toys, and other household items.

[0027] 2. The iron-red glaze formula disclosed in this invention uses vanadium-titanium magnetite as the colorant. The iron element in vanadium-titanium magnetite is introduced into the glaze in the form of Fe3O4, unlike commercially available iron-red glazes which use chemical reagent Fe2O3 or Fe2O3 from hematite as the colorant. Currently, there are no commercially available iron-red glazes using vanadium-titanium magnetite as the colorant; therefore, this invention fills the gap in the production of iron-red glaze using vanadium-titanium magnetite.

[0028] 3. The iron-red glaze produced by this invention is vibrant and dynamic, rich in variation. The fiery red glaze is interspersed with yellow thread-like flow patterns, creating a dazzling and colorful effect that imbues the entire vessel with a rare, noble, and dignified quality. Unlike other iron-red glazes that are dull, this one often features a few clusters of red with yellow edges floating on a brownish-black base glaze. It has no special requirements for the body of the vessel and is suitable for ordinary pottery and porcelain. It possesses high ornamental and practical value, primarily used for tea bowls, cups, and other tea ceremony utensils, but can also be used for bowls, plates, toys, inkstones, and other daily necessities.

[0029] 4. The iron-red glaze disclosed in this invention has a maximum firing temperature of 1240-1250℃ and a firing cycle of about 6.3-9.3 hours. It belongs to the medium-temperature glaze category and has the characteristics of wide applicability, can be used in most electric kilns, short firing cycle, low energy consumption, and high production efficiency.

[0030] 5. The iron-red glaze disclosed in this invention is a raw ore glaze, unlike frit glazes which require multiple sintering processes, have long production flows, and high production costs. It is also not a chemical glaze commonly found in the market, which is formulated with chemical reagents, has a low firing temperature, and produces a dull color lacking vibrancy. Furthermore, the iron-red glaze process of this invention uses environmentally friendly raw ore materials in the glaze, and is fired at medium to high temperatures. No toxic raw materials such as lead or cadmium are introduced into the glaze, eliminating the risk of lead or cadmium leaching, reducing environmental pollution, making it safe, reliable, and more widely applicable.

[0031] Attached Invention

[0032] Figure 1 This is a schematic diagram of the process flow of the present invention;

[0033] Figure 2 The images show the iron-red glaze prepared in Examples 1-5 on a light-colored porcelain body, where 1-5 represent Examples 1-5 respectively.

[0034] Figure 3 The images show the iron-red glaze prepared in Comparative Examples 1-5 on light-colored porcelain bodies, where 1-5 represent Comparative Examples 1-5 respectively.

[0035] Figure 4 This is a photograph of the actual iron-red glaze of the present invention;

[0036] Figures 5-9 The following are the iron red sintering temperature curves of Examples 1 to 5 of the present invention, respectively. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0038] The materials used in the embodiments of the present invention are white kaolin, potassium feldspar, calcite, quartz, calcined talc, bone meal, and vanadium-titanium magnetite from the Panxi region. Among them, the white kaolin, potassium feldspar, calcite, quartz, and calcined talc from the Panxi region can be selected from conventional raw materials (the mineral composition of raw materials from different regions is similar). The chemical composition of the mineral raw materials bone meal and vanadium-titanium magnetite is shown in Table 1.

[0039] Table 1:

[0040] name <![CDATA[SiO2]]> <![CDATA[Al2O3]]> CaO MgO <![CDATA[K2O]]> <![CDATA[Na2O]]> <![CDATA[Fe2O3]]> <![CDATA[TiO2]]> <![CDATA[Fe3O4]]> <![CDATA[P2O5]]> Loss on ignition Vanadium-titanium magnetite 7.07 1.80 2.20 2.00 4.72 5.13 — 6.79 63.01 — 7.28 bone meal 2.35 0.74 45.98 1.40 0.03 0.53 0.14 0.04 — 48.79 —

[0041] Note: The above values ​​are percentages of mass.

[0042] Example 1

[0043] A method for preparing iron oxide red glaze from ceramic raw materials is provided, comprising the following steps:

[0044] 1. Weigh the materials according to the following proportions: 15.5 parts potassium feldspar, 22.5 parts sodium feldspar, 8 parts white kaolin, 14 parts quartz, 6 parts calcite, 10 parts calcined talc, 10 parts bone meal, and 16 parts vanadium-titanium magnetite.

[0045] 2. Add water to the raw material from step 1, place it in a high-speed ball mill, control the mass ratio of material:ball:water to 1:2:0.8, and ball mill for 8 minutes.

[0046] 3. Pass the glaze slurry from step 2 through a 250-mesh standard sieve, and the residue should be less than 0.5%;

[0047] 4. Pour the glaze from step 3 into a glaze cup, seal it with plastic wrap, and place it in a dry, cool place to age for at least 24 hours.

[0048] 5. Remove the clear liquid from the top layer of the aged glaze slurry from step 4, maintaining the glaze slurry specific gravity at 1.65 g / cm³. 3 Then stir it well;

[0049] 6. Apply glaze by dipping. First, wipe the dust off the surface of the unglazed ceramic body with a damp sponge and add water as needed. After the surface of the ceramic body is dry, apply glaze by immersing the ceramic body in the glaze for 7 seconds. After the surface of the glaze is dry, immerse the ceramic body after the first glaze application in the glaze for 3 seconds to keep the glaze thickness at 1.5 mm.

[0050] 7. Allow the glazed ceramic body to air dry naturally;

[0051] 8. Place the sample obtained in step 7 into an electric kiln for firing. Start from room temperature and increase the temperature to 960℃ at a rate of 3.8℃ / min; then increase the temperature to 1120℃ at a rate of 1.1℃ / min; then increase the temperature to 1240℃ at a rate of 1℃ / min and hold for 20 minutes; finally stop heating and let the furnace cool to room temperature to obtain the iron red glaze product. The firing time is about 9.3 hours.

[0052] The iron-red glaze prepared in this embodiment has a color difference of L: 22.55, a: 18.47, b: 12.93, a gloss of 55.6, and thermal shock resistance: it does not crack after three rapid cooling cycles from 200℃ to 20℃. The fiery red glaze surface has a yellowish tinge, the red flowers tend to darken, and it is adorned with golden yellow particles or halos, with a unique, varied, and multi-layered color.

[0053] Example 2

[0054] A method for preparing iron oxide red glaze from ceramic raw materials is provided, comprising the following steps:

[0055] 1. Weigh the materials according to the following proportions: 15.5 parts potassium feldspar, 22.5 parts sodium feldspar, 8 parts white kaolin, 14 parts quartz, 6 parts calcite, 10 parts calcined talc, 10 parts bone meal, and 16 parts vanadium-titanium magnetite.

[0056] 2. Add water to the raw material from step 1, place it in a high-speed ball mill, control the mass ratio of material:ball:water to 1:2:0.8, and ball mill for 8 minutes.

[0057] 3. Pass the glaze slurry from step 2 through a 250-mesh standard sieve, and the residue should be less than 0.5%;

[0058] 4. Pour the glaze from step 3 into a glaze cup, seal it with plastic wrap, and place it in a dry, cool place to age for at least 24 hours.

[0059] 5. Remove the clear liquid from the top layer of the aged glaze slurry from step 4, maintaining the glaze slurry specific gravity at 1.72 g / cm³. 3 Then stir it well;

[0060] 6. Apply glaze by dipping. First, wipe the dust off the surface of the unglazed ceramic body with a damp sponge and add water as needed. After the surface of the ceramic body is dry, apply glaze by immersing the ceramic body in the glaze for 8 seconds. After the surface of the glaze is dry, immerse the ceramic body in the glaze for another 4 seconds to keep the glaze thickness at 1.8 mm.

[0061] 7. Allow the glazed ceramic body to air dry naturally;

[0062] 8. Place the sample obtained in step 7 into an electric kiln for firing. Start from room temperature and increase the temperature at a rate of 7.6℃ / min to 960℃; then increase the temperature at a rate of 1.1℃ / min to 1120℃; then increase the temperature at a rate of 2.0℃ / min to 1200℃; then increase the temperature at a rate of 1.0℃ / min to 1250℃ and hold for 20 minutes; finally stop heating and cool the sample with the furnace to room temperature to obtain the iron red glaze product. The firing time is about 6.3 hours.

[0063] The iron-red glaze prepared in this embodiment has a color difference of L: 23.85, a: 18.20, b: 12.94, a gloss of 55.6, and thermal shock resistance: it does not crack after being rapidly cooled three times from 200℃ to 20℃. The color is vermilion, deep and rich, with uniform and smooth glaze, and the glaze surface is clean and has a strong glassy texture.

[0064] Example 3

[0065] A method for preparing iron oxide red glaze from ceramic raw materials is provided, comprising the following steps:

[0066] 1. Weigh the materials according to the following proportions: 15.5 parts potassium feldspar, 22.5 parts sodium feldspar, 8 parts white kaolin, 18 parts quartz, 6 parts calcite, 10 parts calcined talc, 10 parts bone meal, and 14 parts vanadium-titanium magnetite.

[0067] 2. Add water to the raw material from step 1, place it in a high-speed ball mill, control the mass ratio of material:ball:water to 1:2:0.8, and ball mill for 8 minutes.

[0068] 3. Pass the glaze slurry from step 2 through a 250-mesh standard sieve, and the residue should be less than 0.5%;

[0069] 4. Pour the glaze from step 3 into a glaze cup, seal it with plastic wrap, and place it in a dry, cool place to age for at least 24 hours.

[0070] 5. Remove the clear liquid from the top layer of the aged glaze slurry from step 4, maintaining the glaze slurry specific gravity at 1.68 g / cm³. 3 Then stir it well;

[0071] 6. Apply glaze by dipping. First, wipe the dust off the surface of the unglazed ceramic body with a damp sponge and add water as needed. After the surface of the ceramic body is dry, apply glaze by immersing the ceramic body in the glaze for 7 seconds. After the surface of the glaze is dry, immerse the ceramic body after the first glaze application in the glaze for 3 seconds to keep the glaze thickness at 1.5 mm.

[0072] 7. Allow the glazed ceramic body to air dry naturally;

[0073] 8. Place the sample obtained in step 7 into an electric kiln for firing. Start from room temperature and increase the temperature at a rate of 7.6℃ / min to 960℃; then increase the temperature at a rate of 1.1℃ / min to 1120℃; then increase the temperature at a rate of 4.0℃ / min to 1200℃; then increase the temperature at a rate of 0.6℃ / min to 1250℃ and hold for 20 minutes; finally stop heating and cool the sample with the furnace to room temperature to obtain the iron red glaze product. The firing time is about 6.5 hours.

[0074] The iron-red glaze prepared in this embodiment has a color difference of L: 23.60, a: 17.18, b: 13.65, a gloss of 60, and thermal shock resistance: it does not crack after three rapid cooling cycles from 200℃ to 20℃. The glaze surface is like orange peel, with fine flocculent particles visible to the naked eye, and scattered yellow-green moss spots. It is soft, elegant, and has a unique charm.

[0075] Example 4

[0076] A method for preparing iron oxide red glaze from ceramic raw materials is provided, comprising the following steps:

[0077] 1. Weigh the materials according to the following proportions: 15.5 parts potassium feldspar, 22.5 parts sodium feldspar, 8 parts white kaolin, 18 parts quartz, 6 parts calcite, 10 parts calcined talc, 10 parts bone meal, and 14 parts vanadium-titanium magnetite.

[0078] 2. Add water to the raw material from step 1, place it in a high-speed ball mill, control the mass ratio of material:ball:water to 1:2:0.8, and ball mill for 8 minutes.

[0079] 3. Pass the glaze slurry from step 2 through a 250-mesh standard sieve, and the residue should be less than 0.5%;

[0080] 4. Pour the glaze from step 3 into a glaze cup, seal it with plastic wrap, and place it in a dry, cool place to age for at least 24 hours.

[0081] 5. Remove the clear liquid from the top layer of the aged glaze slurry from step 4, maintaining the glaze slurry specific gravity at 1.72 g / cm³. 3 Then stir it well;

[0082] 6. Apply glaze by dipping. First, wipe the dust off the surface of the unglazed ceramic body with a damp sponge and add water as needed. After the surface of the ceramic body is dry, apply glaze by immersing the ceramic body in the glaze for 9 seconds. After the surface of the glaze is dry, immerse the ceramic body after the first glaze application in the glaze for 3 seconds to keep the glaze thickness at about 1.8 mm.

[0083] 7. Allow the glazed ceramic body to air dry naturally;

[0084] 8. Place the sample obtained in step 7 into an electric kiln for firing. Start from room temperature and increase the temperature at a rate of 7.6℃ / min to 960℃; then increase the temperature at a rate of 1.1℃ / min to 1120℃; then increase the temperature at a rate of 2.0℃ / min to 1200℃; then increase the temperature at a rate of 1.0℃ / min to 1250℃ and hold for 20 minutes; finally stop heating and cool the sample with the furnace to room temperature to obtain the iron red glaze product. The firing time is about 6.3 hours.

[0085] The iron-red glaze prepared in this embodiment has a color difference of L: 22.27, a: 16.56, b: 13.62, a gloss of 33.6, and thermal shock resistance: it does not crack after being rapidly cooled three times from 200℃ to 20℃. The glaze color is iron-red, with a color like jujube skin, bright and deep, and has a certain gloss. Tiny red crystals can be seen on the surface.

[0086] Example 5

[0087] A method for preparing iron oxide red glaze from ceramic raw materials is provided, comprising the following steps:

[0088] 1. Weigh the materials according to the following proportions: 15.5 parts potassium feldspar, 22.5 parts sodium feldspar, 8 parts white kaolin, 18 parts quartz, 6 parts calcite, 10 parts calcined talc, 14 parts bone meal, and 16 parts vanadium-titanium magnetite.

[0089] 2. Add water to the raw material from step 1, place it in a high-speed ball mill, control the mass ratio of material:ball:water to 1:2:0.8, and ball mill for 8 minutes.

[0090] 3. Pass the glaze slurry from step 2 through a 250-mesh standard sieve, and the residue should be less than 0.5%;

[0091] 4. Pour the glaze from step 3 into a glaze cup, seal it with plastic wrap, and place it in a dry, cool place to age for at least 24 hours.

[0092] 5. Remove the clear liquid from the top layer of the aged glaze slurry from step 4, maintaining the glaze slurry specific gravity at 1.75 g / cm³. 3 Then stir it well;

[0093] 6. Apply glaze by dipping. First, wipe the dust off the surface of the unglazed ceramic body with a damp sponge and add water as needed. After the surface of the ceramic body is dry, apply glaze by immersing the ceramic body in the glaze for 8 seconds. After the surface of the glaze is dry, immerse the ceramic body after the first glaze application in the glaze for 4 seconds to keep the glaze thickness at 1.8 mm.

[0094] 7. Allow the glazed ceramic body to air dry naturally;

[0095] 8. Place the sample obtained in step 7 into an electric kiln for firing. Start from room temperature and increase the temperature at a rate of 7.6℃ / min to 960℃; then increase the temperature at a rate of 1.1℃ / min to 1120℃; then increase the temperature at a rate of 2.0℃ / min to 1200℃; then increase the temperature at a rate of 1.0℃ / min to 1250℃ and hold for 20 minutes; finally stop heating and cool the sample with the furnace to room temperature to obtain the iron red glaze product. The firing time is about 6.3 hours.

[0096] The iron-red glaze prepared in this embodiment has a color difference of L: 27.13, a: 17.58, b: 13.52, a gloss of 14.9, and thermal shock resistance: it does not crack after three rapid cooling cycles from 200℃ to 20℃. The glaze surface is bright and even, with certain red flow lines, and meets the color requirements of iron-red glaze.

[0097] The photographs of the iron-red glaze prepared in Examples 1-5 on light-colored porcelain bodies are shown below. Figure 2 As shown, Figure 2 The numbers 1 to 5 in the text represent Examples 1 to 5, respectively.

[0098] Comparative Example 1

[0099] A method for preparing iron oxide red glaze from ceramic raw materials is provided, comprising the following steps:

[0100] 1. Weigh the materials according to the following proportions: 17.5 parts potassium feldspar, 22.5 parts sodium feldspar, 9 parts white kaolin, 18 parts quartz, 6 parts calcite, 10 parts calcined talc, 12 parts bone meal, 12 parts vanadium-titanium magnetite, and 4 parts zinc oxide.

[0101] 2. Add water to the raw material from step 1, place it in a high-speed ball mill, control the mass ratio of material:ball:water to 1:2:0.8, and ball mill for 8 minutes.

[0102] 3. Pass the glaze slurry from step 2 through a 250-mesh standard sieve, and the residue should be less than 0.5%;

[0103] 4. Pour the glaze from step 3 into a glaze cup, seal it with plastic wrap, and place it in a dry, cool place to age for at least 24 hours.

[0104] 5. Remove the clear liquid from the top layer of the aged glaze slurry from step 4, maintaining the glaze slurry specific gravity at 1.69 g / cm³. 3 Then stir it well;

[0105] 6. Apply glaze by dipping. First, wipe the dust off the surface of the unglazed ceramic body with a damp sponge and add water as needed. After the surface of the ceramic body is dry, apply glaze by immersing the ceramic body in the glaze for 8 seconds. After the surface of the glaze is dry, immerse the ceramic body in the glaze for 4 seconds to keep the glaze thickness at 1.8 mm.

[0106] 7. Allow the glazed ceramic body to air dry naturally;

[0107] 8. Place the sample obtained in step 7 into an electric kiln for firing. Start from room temperature and increase the temperature at a rate of 3.8℃ / min to 960℃; then increase the temperature at a rate of 0.9℃ / min to 1120℃; then increase the temperature at a rate of 0.8℃ / min to 1240℃ and hold for 20 minutes; finally stop heating and let the furnace cool to room temperature to obtain the iron red glaze product. The firing time is about 9.8 hours.

[0108] The iron-red glaze prepared in this comparative example has a color difference of L: 16.69, a: 8.07, b: 11.9, a gloss of 17.9, and thermal shock resistance: it does not crack after three rapid cooling cycles from 200℃ to 20℃. The glaze surface exhibits a yellowish-white and reddish-brown dispersed appearance, with brownish-black fringes at the edges. The iron-red crystals are small and scattered, without any iron-red effect.

[0109] Comparative Example 2

[0110] A method for preparing iron oxide red glaze from ceramic raw materials is provided, comprising the following steps:

[0111] 1. Weigh the materials according to the following proportions: 15.5 parts potassium feldspar, 22.5 parts sodium feldspar, 8 parts white kaolin, 20 parts quartz, 6 parts calcite, 10 parts calcined talc, 10 parts bone meal, and 12 parts vanadium-titanium magnetite.

[0112] 2. Add water to the raw material from step 1, place it in a high-speed ball mill, control the mass ratio of material:ball:water to 1:2:0.8, and ball mill for 8 minutes.

[0113] 3. Pass the glaze slurry from step 2 through a 250-mesh standard sieve, and the residue should be less than 0.5%;

[0114] 4. Pour the glaze from step 3 into a glaze cup, seal it with plastic wrap, and place it in a dry, cool place to age for at least 24 hours.

[0115] 5. Remove the clear liquid from the top layer of the aged glaze slurry from step 4, maintaining the glaze slurry specific gravity at 1.65 g / cm³. 3 Then stir it well;

[0116] 6. Apply glaze by dipping. First, wipe the dust off the surface of the unglazed ceramic body with a damp sponge and add water as needed. After the surface of the ceramic body is dry, apply glaze by immersing the ceramic body in the glaze for 8 seconds. After the surface of the glaze is dry, immerse the ceramic body after the first glaze application in the glaze for 3 seconds to keep the glaze thickness at 1.5mm.

[0117] 7. Allow the glazed ceramic body to air dry naturally;

[0118] 8. Place the sample obtained in step 7 into an electric kiln for firing. Start from room temperature and increase the temperature at a rate of 7.6℃ / min to 960℃; then increase the temperature at a rate of 1.1℃ / min to 1120℃; then increase the temperature at a rate of 2.0℃ / min to 1200℃; then increase the temperature at a rate of 1.0℃ / min to 1250℃ and hold for 20 minutes; finally stop heating and cool the sample with the furnace to room temperature to obtain the iron red glaze product. The firing time is about 6.3 hours.

[0119] The iron-red glaze prepared in this comparative example has a color difference of L: 18.39, a: 12.74, b: 11.64, a gloss of 23.8, and thermal shock resistance: it does not crack after three rapid cooling cycles from 200℃ to 20℃. The blackish-brown glaze surface has a large number of iron-red crystals distributed on it. The crystals are numerous and dense at the edges of the discs, while the iron-red crystals in the central area are scattered and not dense, and it does not have the effect of iron-red glaze.

[0120] Comparative Example 3

[0121] A method for preparing iron oxide red glaze from ceramic raw materials is provided, comprising the following steps:

[0122] 1. Weigh the materials according to the following proportions: 17.5 parts potassium feldspar, 22.5 parts sodium feldspar, 9 parts white kaolin, 18 parts quartz, 6 parts calcite, 10 parts calcined talc, 12 parts bone meal, 12 parts vanadium-titanium magnetite, and 4 parts zirconium oxide.

[0123] 2. Add water to the raw material from step 1, place it in a high-speed ball mill, control the mass ratio of material:ball:water to 1:2:0.8, and ball mill for 8 minutes.

[0124] 3. Pass the glaze slurry from step 2 through a 250-mesh standard sieve, and the residue should be less than 0.5%;

[0125] 4. Pour the glaze from step 3 into a glaze cup, seal it with plastic wrap, and place it in a dry, cool place to age for at least 24 hours.

[0126] 5. Remove the clear liquid from the top layer of the aged glaze slurry from step 4, maintaining the glaze slurry specific gravity at 1.70 g / cm³. 3 Then stir it well;

[0127] 6. Apply glaze by dipping. First, wipe the dust off the surface of the unglazed ceramic body with a damp sponge and add water as needed. After the surface of the ceramic body is dry, apply glaze by immersing the ceramic body in the glaze for 9 seconds. After the surface of the glaze is dry, immerse the ceramic body after the first glaze application in the glaze for 3 seconds to keep the glaze thickness at 1.8 mm.

[0128] 7. Allow the glazed ceramic body to air dry naturally;

[0129] 8. Place the sample obtained in step 7 into an electric kiln for firing. Start from room temperature and increase the temperature to 700℃ at a rate of 2.7℃ / min; then increase the temperature to 1120℃ at a rate of 2.1℃ / min; then increase the temperature to 1280℃ at a rate of 2.0℃ / min and hold for 20 minutes; finally stop heating and let the furnace cool to room temperature to obtain the iron red glaze product. The firing time is about 9 hours.

[0130] The iron-red glaze prepared in this comparative example has a color difference of L: 26.37, a: 5.6, b: 11.82, a gloss of 62.7, and thermal shock resistance: it does not crack after three rapid cooling cycles from 200℃ to 20℃. The glaze surface has fine yellow flocculent particles that are visible to the naked eye, and it does not have the effect of iron red.

[0131] Comparative Example 4

[0132] A method for preparing iron oxide red glaze from ceramic raw materials is provided, comprising the following steps:

[0133] 1. Weigh the materials according to the following proportions: 17.5 parts potassium feldspar, 22.5 parts sodium feldspar, 8 parts white kaolin, 18 parts quartz, 6 parts calcite, 10 parts calcined talc, 14 parts bone meal, and 12 parts vanadium-titanium magnetite.

[0134] 2. Add water to the raw material from step 1, place it in a high-speed ball mill, control the mass ratio of material:ball:water to 1:2:0.8, and ball mill for 8 minutes.

[0135] 3. Pass the glaze slurry from step 2 through a 250-mesh standard sieve, and the residue should be less than 0.5%;

[0136] 4. Pour the glaze from step 3 into a glaze cup, seal it with plastic wrap, and place it in a dry, cool place to age for at least 24 hours.

[0137] 5. Remove the clear liquid from the top layer of the aged glaze slurry from step 4, maintaining the glaze slurry specific gravity at 1.72 g / cm³. 3 Then stir it well;

[0138] 6. Apply glaze by dipping. First, wipe the dust off the surface of the unglazed ceramic body with a damp sponge and add water as needed. After the surface of the ceramic body is dry, apply glaze by immersing the ceramic body in the glaze for 8 seconds. After the surface of the glaze is dry, immerse the ceramic body in the glaze for 3 seconds after the first application of glaze to keep the glaze thickness at 1.8 mm.

[0139] 7. Allow the glazed ceramic body to air dry naturally;

[0140] 8. Place the sample obtained in step 7 into an electric kiln for firing. Start at room temperature and raise the temperature to 700℃ at a rate of 3.6℃ / min; then raise the temperature to 1120℃ at a rate of 3.5℃ / min; then raise the temperature to 1230℃ at a rate of 1℃ / min and hold for 20 minutes; finally stop heating and let the furnace cool to room temperature to obtain the iron red glaze product. The firing time is about 7.8 hours.

[0141] The iron-red glaze prepared in this comparative example has a color difference of L: 18.39, a: 12.74, b: 11.64, a gloss of 24.4, and thermal shock resistance: it does not crack after three rapid cooling cycles from 200℃ to 20℃. The iron-red crystals are phase-separated and distributed as oil droplets on a dark brown background, without any iron-red effect.

[0142] Comparative Example 5

[0143] A method for preparing iron oxide red glaze from ceramic raw materials is provided, comprising the following steps:

[0144] 1. Weigh the materials according to the following parts by weight: 17.5 parts potassium feldspar, 22.5 parts sodium feldspar, 9 parts white kaolin, 18 parts quartz, 6 parts calcite, 10 parts calcined talc, 12 parts bone meal, 12 parts Yunnan magnetite, and 4 parts zirconium oxide. The Yunnan magnetite, by mass percentage, comprises: SiO2: 7.63%, Al2O3: 3.69%, CaO: 0.76%, MgO: 1.94%, K2O: 3.25%, Na2O: 4.67%, TiO2: 29.12%, Fe3O4: 39.10%, and loss on ignition: 9.84%.

[0145] 2. Add water to the raw material from step 1, place it in a high-speed ball mill, control the mass ratio of material:ball:water to 1:2:0.8, and ball mill for 8 minutes.

[0146] 3. Pass the glaze slurry from step 2 through a 250-mesh standard sieve, and the residue should be less than 0.5%;

[0147] 4. Pour the glaze from step 3 into a glaze cup, seal it with plastic wrap, and place it in a dry, cool place to age for at least 24 hours.

[0148] 5. Remove the clear liquid from the top layer of the aged glaze slurry from step 4, maintaining the glaze slurry specific gravity at 1.70 g / cm³. 3 Then stir it well;

[0149] 6. Apply glaze by dipping. First, wipe the dust off the surface of the bisque-fired ceramic body with a damp sponge and add water as needed. After the surface of the ceramic body is dry, apply glaze by immersing the ceramic body in the glaze for 8 seconds. After the surface of the glaze is dry, apply glaze a second time by immersing the ceramic body after the first glaze in the glaze for 3 seconds to keep the glaze thickness at 1.8 mm.

[0150] 7. Allow the glazed ceramic body to air dry naturally;

[0151] 8. Place the sample obtained in step 7 into an electric kiln for firing. Start from room temperature and increase the temperature to 700℃ at a rate of 2.7℃ / min; then increase the temperature to 1120℃ at a rate of 2.8℃ / min; then increase the temperature to 1260℃ at a rate of 0.9℃ / min and hold for 20 minutes; finally stop heating and let the furnace cool to room temperature to obtain the iron red glaze product. The firing time is about 9.3 hours.

[0152] The iron-red glaze prepared in this comparative example has a color difference of L: 29.83, a: 8.46, b: 14.42, a gloss of 6.9, and thermal shock resistance: it does not crack after three rapid cooling cycles from 200℃ to 20℃. The glaze surface basically does not show iron-red crystals and is brownish-brown overall, without the effect of iron-red glaze.

[0153] Photographs of the iron-red glazes prepared in Comparative Examples 1-5 on light-colored porcelain bodies are shown below. Figure 3 As shown, Figure 3 Numbers 1 through 5 in the table represent comparative examples 1 through 5, respectively.

[0154] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A ceramic raw material iron-red glaze, characterized in that, Its raw materials include the following components by weight: 15.5-17.5 parts potassium feldspar, 22.5-23.5 parts sodium feldspar, 7-8 parts white kaolin from the Panxi region, 14-18 parts quartz, 6-7 parts calcite, 10-12 parts calcined talc, 10-12 parts bone meal, and 14-16 parts vanadium-titanium magnetite. The bone powder comprises, by weight percentage: SiO2: 0.85–2.35%, Al2O3: 0.36–0.74%, CaO: 44.56–46.75%, MgO: 0.76–1.50%, K2O: 0.03–0.12%, Na2O: 0.53–0.86%, Fe2O3: 0.12–0.14%, TiO2: 0.03–0.05%, P2O5: 36.76–48.79%, with the balance being unavoidable impurities. The vanadium-titanium magnetite comprises, by mass percentage: SiO2: 6.88–7.07%, Al2O3: 1.65–1.80%, CaO: 1.96–2.20%, MgO: 1.67–2.00%, K2O: 4.55–4.72%, Na2O: 4.82–5.13%, TiO2: 6.03–6.79%, Fe3O4: 62.15–63.01%, loss on ignition: 10.26–7.28%, with the balance being unavoidable impurities.

2. The ceramic raw material iron-red glaze according to claim 1, characterized in that, Potassium feldspar 15.5 parts, sodium feldspar 22.5 parts, white kaolin from the Panxi region 8 parts, quartz 14-18 parts, calcite 6 parts, calcined talc 10 parts, bone meal 10 parts, vanadium-titanium magnetite 14-16 parts.

3. The ceramic raw material iron-red glaze according to claim 1, characterized in that, The color difference of the iron-red glaze is L: 22.27~27.13, a: 16.56~18.47, b: 12.93~13.65, and the gloss is 14.9~60. Thermal shock resistance: 3 times of rapid cooling at 200℃~20℃ without cracking.

4. The method for preparing ceramic raw material iron-red glaze according to any one of claims 1-3, characterized in that, Includes the following steps: (1) Weighing: Weigh each raw material according to its components; (2) Ball milling and sieving: The raw materials weighed in step (1) are ball milled to obtain glaze slurry, and then the glaze slurry is sieved through a 250-mesh standard sieve. (3) Aging: Seal the glaze slurry after sieving in step (2) and place it in a dry and cool place to age for more than 24 hours; (4) Glazing and drying: Remove the upper clear liquid from the glaze slurry after aging in step (3), and maintain the specific gravity of the glaze slurry at 1.65-1.75 g / cm³. 3 After stirring evenly, the glaze is applied to the surface of the ceramic body, and then the glazed ceramic body is dried. (5) Firing: The ceramic blank dried in step (4) is heated from room temperature to 960-980℃ at a heating rate of 3.8-7.6℃ / min; then heated to 1120-1130℃ at a heating rate of 1.1-1.2℃ / min; then heated to 1200-1210℃ at a heating rate of 2.0-4.0℃ / min; finally heated to 1240-1250℃ at a heating rate of 0.6-1.0℃ / min and held at that temperature for 20-30 minutes; finally, heating is stopped and the ceramic blank is cooled to room temperature in the furnace to obtain the iron red glaze product. Alternatively, the ceramic blank dried in step (4) can be heated from room temperature to 960-980℃ at a heating rate of 3.8-7.6℃ / min; then heated to 1120-1130℃ at a heating rate of 1.1-1.2℃ / min; then heated to 1240-1250℃ at a heating rate of 1.0-1.2℃ / min and held at that temperature for 20-30 minutes; finally, heating can be stopped and the blank can be cooled to room temperature in the furnace to obtain the iron red glaze product.

5. The method for preparing iron-red glaze from ceramic raw materials according to claim 4, characterized in that, In step (2), the mass ratio of raw material:ball:water in the ball mill is controlled to be 1:2:0.8 to 1:2.5:1, and the ball milling time is 8 to 10 minutes.

6. The method for preparing iron-red glaze from ceramic raw materials according to claim 4, characterized in that, In step (2), the sample is passed through a 250-mesh standard sieve, and the residue is less than 0.5%.

7. The method for preparing iron-red glaze from ceramic raw materials according to claim 4, characterized in that, In step (4), glazing is done by immersion glazing. Each time, the ceramic body is immersed in the glaze slurry and then taken out. After the glaze on the surface of the body dries, it is immersed in the glaze again, so that the thickness of the glaze layer is kept between 1 and 2 mm.

8. The method for preparing iron-red glaze from ceramic raw materials according to claim 4, characterized in that, The glazed ceramic body is dried by natural air drying or by placing it in a drying oven at 50-80℃ for 3-5 hours.

9. The method for preparing iron-red glaze from ceramic raw materials according to claim 4, characterized in that, In step (4), the surface of the ceramic body is cleaned and water is added before glazing. The ceramic body is glazed after it has dried.

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