Non-reducing atmosphere fired celeste glaze and preparation method thereof

Abstract

The invention discloses celeste glaze fired in a non-reducing atmosphere and a preparation method of the celeste glaze. The celeste glaze provided by the invention is prepared from the following raw materials in percentage by mass: 56 to 60 percent of feldspar, 15 to 18 percent of quartz, 10 to 13 percent of calcite, 1 to 3 percent of talc, 5 to 8 percent of kaolin and 6 to 8 percent of celadon pigment. The main crystalline phase of the celadon pigment is zirconium silicate, vanadium ions and iron ions playing a coloring role are wrapped outside the zirconium silicate, the molar concentration of the vanadium ions is 2%-4%, and the molar concentration of the iron ions is 1%-3%. According to the method, the vanadium iron ion celadon pigment wrapped by the high-temperature pre-stabilized zirconium silicate is used as the coloring agent, and the celeste blue glazed porcelain is fired in the non-reducing atmosphere, so that the core problem existing in the traditional firing in the reducing atmosphere is successfully solved. And ferrovanadium ions in the coloring agent are stably wrapped in zirconium silicate crystals and are not influenced by the fluctuation of the firing atmosphere, so that the consistency of the glaze color of the same batch of celeste glaze is ensured. Regulation and control of the celeste glaze color are achieved through the adding amount of the celadon pigment, operation is easy, convenient and visual, and dependence on technical experience of operators is reduced.

Description

Technical Field

[0001] This invention relates to the field of traditional ceramic manufacturing technology, specifically to a method for preparing celadon glaze fired in a non-reducing atmosphere. Background Technology

[0002] With its warm, serene, and elegant color, celadon glaze has become a classic category of celadon glazes. Ancient Chinese pottery texts describe it as "blue as the sky, bright as a mirror," a precise depiction of its vibrant blue color and mirror-like finish, fully showcasing the artistic charm and cultural heritage of celadon glaze. In the traditional glaze porcelain system where "blue is valued most," celadon glaze porcelain, with its unique aesthetic qualities, is highly favored worldwide and enjoys a high reputation both domestically and internationally.

[0003] In traditional techniques, the color of celadon glaze primarily relies on the reducing atmosphere firing process. Specifically, the small amount of iron oxide in the glaze undergoes a valence state transformation under high-temperature reducing conditions, generating ferrous oxide. This chemical reaction is the key mechanism for achieving the typical color of celadon glaze. However, traditional reducing atmosphere firing technology has significant limitations: on the one hand, precise control of the reducing atmosphere is extremely difficult; even slight differences in the local atmosphere within the kiln can lead to significant deviations in glaze color within the same batch of products, severely affecting the uniformity of celadon glaze; on the other hand, this process places stringent requirements on kiln structure, fuel type, and firing parameters, not only complicating the preparation process of celadon glaze but also resulting in high production costs, thus hindering the large-scale development of the celadon glaze industry. Summary of the Invention

[0004] The purpose of this invention is to provide a non-reducing atmosphere firing method for celadon glaze, which solves the problems of difficult precise control of the reducing atmosphere during firing, stringent requirements for kiln structure, and uneven and unstable glaze color.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] On one hand, the present invention provides a non-reducing atmosphere fired celadon glaze, wherein the raw materials of the celadon pigment include the following components by mass percentage: feldspar 56%-60%, quartz 15%-18%, calcite 10%-13%, talc 1%-3%, kaolin 5%-8%, and celadon pigment 6%-8%; the main crystalline phase of the celadon pigment is zirconium silicate, with vanadium ions and iron ions that play a coloring role encapsulated around the zirconium silicate, wherein the molar concentration of vanadium ions is 2%-4%, and the molar concentration of iron ions is 1%-3%. The raw materials of the celadon pigment include the following components by mass percentage: 59.82%-63.18% zirconium oxide, 29.18%-30.82% silicon oxide, 2%-5% ammonium metavanadate, 1%-4% ferrous sulfate, 1%-2% titanium dioxide, and 1%-2% mineralizer; wherein the mass ratio of zirconium oxide to silicon oxide is 2.05:1; the celadon pigment is obtained by ball milling and mixing the above raw materials, calcining at 950℃-1000℃ and cooling to room temperature, pulverizing and sieving.

[0007] Furthermore, the mineralizing agent is sodium fluoride.

[0008] On the other hand, the present invention also provides a method for preparing celadon glaze fired in a non-reducing atmosphere, comprising the following steps:

[0009] Step 1: Glaze preparation: Take 56%-60% feldspar, 15%-18% quartz, 10%-13% calcite, 1%-3% talc, 5%-8% kaolin, and 6%-8% celadon pigment by weight and put them into a ball mill jar. Then add alumina balls and water, and ball mill on a high-speed ball mill for 40 minutes to obtain glaze slurry.

[0010] Step 2: Glazing: Immerse the cleaned ceramic body in the glaze slurry and let it dry naturally to obtain a glazed body. The thickness of the glaze layer is controlled at 1-1.5mm.

[0011] Step 3: Firing: Place the glazed blank obtained in Step 2 in an electric kiln and fire it at 1260℃-1280℃ for 30 minutes. Then cool it to room temperature with the kiln to obtain celadon porcelain.

[0012] Furthermore, in step 1, the mass ratio of material, balls, and water added to the ball mill jar is 1:3:0.6.

[0013] Furthermore, in step 3, the heating rate of the electric kiln during the firing process is 5°C / min.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] This invention utilizes a high-temperature pre-stabilized zirconium silicate-encapsulated vanadium-iron ion celadon pigment as a colorant, firing celadon glaze in a non-reducing atmosphere, successfully solving a core problem inherent in traditional reducing atmosphere firing. In traditional processes, the reducing atmosphere within the kiln is difficult to control precisely; even slight differences in the local atmosphere can lead to significant deviations in glaze color within the same batch of products, severely affecting the uniformity of the celadon glaze. In this invention, the vanadium-iron ions in the colorant are stably encapsulated within zirconium silicate crystals. At this point, the vanadium-iron ions are physically isolated from the external glaze matrix and kiln atmosphere by the crystal structure of zirconium silicate, preventing direct contact and eliminating the influence of firing atmosphere fluctuations. This fundamentally ensures the consistency of the celadon glaze color within the same batch, significantly improving product quality stability. The sky-blue glaze is colored by using a vanadium-iron ion compound. By adjusting the ratio of vanadium to iron, the glaze color can be finely adjusted: when the proportion of vanadium ions is high, the glaze color tends to be a deep gray-blue; if the proportion of iron ions increases, the glaze color is closer to a bright greenish-blue. This method of adjusting the glaze color by adjusting the compound ratio not only utilizes the complementary color properties of the two ions, but also provides a flexible and controllable adjustment path for optimizing the color tone of the sky-blue glaze.

[0016] Furthermore, the color of celadon porcelain can be controlled by adjusting the amount of celadon pigment added, a simple and intuitive process. Compared to traditional methods that rely on complex atmosphere control for color regulation, this method is easier to master, significantly reducing the dependence on the operator's technical experience and skill level, thus making the production process easier to control and manage. Attached Figure Description

[0017] Figure 1 This is a picture of the celadon glaze produced in Example 3 of the present invention. Detailed Implementation

[0018] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be described in detail below with reference to specific embodiments.

[0019] Example 1

[0020] A method for preparing sky-blue glaze fired in a non-reducing atmosphere includes the following steps:

[0021] Step 1: Glaze preparation: Take 56% feldspar, 18% quartz, 13% calcite, 2% talc, 5% kaolin and 6% celadon pigment by mass percentage and put them into a ball mill jar. Then add alumina balls and water. The mass ratio of material:ball:water is 1:3:0.6. After ball milling for 40 minutes in a high-speed ball mill, the glaze slurry is obtained.

[0022] The celadon pigment is prepared by the following method: Raw materials are taken according to the following mass percentages: 59.82% zirconium oxide, 29.18% silicon dioxide, 5% ammonium metavanadate, 4% ferrous sulfate, 1% titanium dioxide, and 1% sodium fluoride. These are ball-milled and mixed evenly. After calcination at 975℃ and cooling to room temperature, the mixture is crushed, acid-washed, filtered, and dried to obtain the celadon pigment. The molar concentration of vanadium ions in the mineral celadon pigment is 2%, and the molar concentration of iron ions is 1%.

[0023] Step 2: Glazing: Immerse the cleaned ceramic body in the glaze slurry for about ten seconds, then take it out and let it dry naturally to obtain a glazed body. The thickness of the glaze layer should be controlled at 1mm.

[0024] Step 3: Firing: Place the glazed blank obtained in Step 2 into an electric kiln and heat it to 1280℃ at a heating rate of 5℃ / min to obtain celadon porcelain.

[0025] Example 2:

[0026] A method for preparing sky-blue glaze fired in a non-reducing atmosphere includes the following steps:

[0027] Step 1: Glaze preparation: Take 56% feldspar, 18% quartz, 13% calcite, 2% talc, 5% kaolin and 6% celadon pigment by mass percentage and put them into a ball mill jar. Then add alumina balls and water. The mass ratio of material:ball:water is 1:3:0.6. After ball milling for 40 minutes in a high-speed ball mill, the glaze slurry is obtained.

[0028] The celadon pigment is prepared by the following method: Raw materials are taken according to the following mass percentages: 63.18% zirconium oxide, 30.82% silicon dioxide, 3% ammonium metavanadate, 1% ferrous sulfate, 1% titanium dioxide, and 1% sodium fluoride. These are ball-milled and mixed evenly. After calcination at 975℃ and cooling to room temperature, the mixture is crushed, acid-washed, filtered, and dried to obtain the celadon pigment. The molar concentration of vanadium ions in the celadon pigment is 4%, and the molar concentration of iron ions is 3%.

[0029] Step 2: Glazing: Immerse the cleaned ceramic body in the glaze slurry for about ten seconds, then take it out and let it dry naturally to obtain a glazed body. The thickness of the glaze layer should be controlled at 1.5mm.

[0030] Step 3: Firing: Place the glazed blank obtained in Step 2 into an electric kiln and heat it to 1280℃ at a heating rate of 5℃ / min to obtain celadon porcelain.

[0031] Example 3:

[0032] A method for preparing sky-blue glaze fired in a non-reducing atmosphere includes the following steps:

[0033] Step 1: Glaze preparation: Take 60% feldspar, 15% quartz, 10% calcite, 1% talc, 8% kaolin and 6% celadon pigment by mass percentage and put them into a ball mill jar. Then add alumina balls and water. The mass ratio of material:ball:water is 1:3:0.6. After ball milling for 40 minutes in a high-speed ball mill, the glaze slurry is obtained.

[0034] The celadon pigment was prepared by the following method: 61.16% zirconium oxide, 29.84% silicon oxide, 2% ammonium metavanadate, 4% ferrous sulfate, 1.5% titanium dioxide, and 1.5% sodium fluoride were ball-milled and mixed evenly. After calcination at 975℃ and cooling to room temperature, the pigment was crushed, acid-washed, filtered, and dried to obtain the celadon pigment. The molar concentration of vanadium ions in the celadon pigment was 3%, and the molar concentration of iron ions was 2%.

[0035] Step 2: Glazing: Immerse the cleaned ceramic body into the glaze slurry for about ten seconds, then remove it and let it air dry to obtain a glazed body. The glaze thickness should be controlled at 1.2mm.

[0036] Step 3: Firing: Place the glazed blank obtained in Step 2 into an electric kiln and heat it to 1270℃ at a heating rate of 5℃ / min to obtain celadon porcelain.

[0037] Example 4:

[0038] A method for preparing sky-blue glaze fired in a non-reducing atmosphere includes the following steps:

[0039] Step 1: Glaze preparation: Take 58% feldspar, 16% quartz, 10% calcite, 3% talc, 6% kaolin and 7% celadon pigment by mass percentage and put them into a ball mill jar. Then add alumina balls and water. The mass ratio of material:ball:water is 1:3:0.6. After ball milling for 40 minutes in a high-speed ball mill, the glaze slurry is obtained.

[0040] The celadon pigment is prepared by the following method: raw materials are taken according to the following mass percentages: 61.16% zirconium oxide, 29.84% silicon oxide, 3% ammonium metavanadate, 4% ferrous sulfate, 1% titanium dioxide and 1% sodium fluoride are ball-milled and mixed evenly. The molar concentration of vanadium ions in the celadon pigment is 3% and the molar concentration of iron ions is 2%.

[0041] Step 2: Glazing: Immerse the cleaned ceramic body into the glaze slurry for about ten seconds, then remove it and let it dry naturally to obtain a glazed body. The glaze thickness is controlled at 1.4mm.

[0042] Step 3: Firing: Place the glazed blank obtained in Step 2 into an electric kiln and heat it to 1260℃ at a heating rate of 5℃ / min to obtain celadon porcelain.

[0043] Example 5:

[0044] A method for preparing sky-blue glaze fired in a non-reducing atmosphere includes the following steps:

[0045] Step 1: Glaze preparation: Take 58% feldspar, 16% quartz, 12% calcite, 1% talc, 5% kaolin and 8% celadon pigment by mass percentage and put them into a ball mill jar. Then add alumina balls and water. The mass ratio of material:ball:water is 1:3:0.6. After ball milling for 40 minutes in a high-speed ball mill, the glaze slurry is obtained.

[0046] The celadon pigment is prepared by the following method: Raw materials are taken according to the following mass percentages: 61.16% zirconium oxide, 29.84% silicon dioxide, 3% ammonium metavanadate, 2% ferrous sulfate, 2% titanium dioxide, and 2% sodium fluoride. These are ball-milled and mixed evenly. After calcination at 975℃ and cooling to room temperature, the mixture is crushed, acid-washed, filtered, and dried to obtain the celadon pigment. The molar concentration of vanadium ions in the celadon pigment is 3%, and the molar concentration of iron ions is 2%.

[0047] Step 2: Glazing: Immerse the cleaned ceramic body into the glaze slurry for about ten seconds, then remove it and let it air dry to obtain a glazed body. The glaze thickness should be controlled at 1.3mm.

[0048] Step 3: Firing: Place the glazed blank obtained in Step 2 into an electric kiln and heat it to 1260℃ at a heating rate of 5℃ / min to obtain celadon porcelain.

[0049] Figure 1 The image shows a physical sample of the celadon glaze produced in Example 3 of this invention. As can be seen from the image, the ceramic glaze fired in an electric kiln exhibits a warm, jade-like celadon color, essentially consistent with the celadon glaze fired in a reducing atmosphere. Furthermore, comparative analysis of the celadon glazes prepared in Examples 1-5 revealed that the higher the molar concentration of vanadium and iron ions in the celadon pigment, the deeper the celadon glaze color. This is mainly because vanadium and iron, as transition metal ions, can form tetrahedral or octahedral coordination structures in the glaze, becoming color-producing centers and thus producing the typical celadon color. Similarly, the more celadon pigment added, the higher the concentration of color-producing ions in the glaze, and the deeper the glaze color. Additionally, adjusting the base glaze formula can control the firing temperature of the celadon glaze and the body.

Claims

1. A celadon glaze fired in a non-reducing atmosphere, characterized in that, The raw materials of the celadon pigment include the following components by mass percentage: feldspar 56%-60%, quartz 15%-18%, calcite 10%-13%, talc 1%-3%, kaolin 5%-8%, and celadon pigment 6%-8%. The main crystalline phase of the celadon pigment is zirconium silicate, with vanadium and iron ions that play a coloring role wrapped around the zirconium silicate. The molar concentration of vanadium ions is 2%-4%, and the molar concentration of iron ions is 1%-3%. The raw materials for the celadon pigment include the following components by mass percentage: 59.82%-63.18% zirconium oxide, 29.18%-30.82% silicon oxide, 2%-5% ammonium metavanadate, 1%-4% ferrous sulfate, 1%-2% titanium dioxide, and 1%-2% mineralizer; wherein the mass ratio of zirconium oxide to silicon oxide is 2.05:1; the celadon pigment is obtained by ball milling and mixing the above raw materials, calcining at 950℃-1000℃ and cooling to room temperature, pulverizing and sieving.

2. The sky-blue glaze fired in a non-reducing atmosphere according to claim 1, characterized in that, The mineralizing agent is sodium fluoride.

3. A method for preparing a celadon glaze fired in a non-reducing atmosphere as described in claims 1-2, characterized in that, Includes the following steps: Step 1: Glaze preparation: Take 56%-60% feldspar, 15%-18% quartz, 10%-13% calcite, 1%-3% talc, 5%-8% kaolin, and 6%-8% celadon pigment by weight and put them into a ball mill jar. Then add alumina balls and water, and ball mill on a high-speed ball mill for 40 minutes to obtain glaze slurry. Step 2: Glazing: Immerse the cleaned ceramic body in the glaze slurry and let it dry naturally to obtain a glazed body. The thickness of the glaze layer is controlled at 1-1.5mm. Step 3: Firing: Place the glazed blank obtained in Step 2 in an electric kiln and fire it at 1260℃-1280℃ for 30 minutes. Then cool it to room temperature with the kiln to obtain celadon porcelain.

4. The method for preparing a celadon glaze fired in a non-reducing atmosphere according to claim 3, characterized in that, The mass ratio of material, balls, and water added to the ball mill jar in step 1 is 1:3:0.

6.

5. The method for preparing a celadon glaze fired in a non-reducing atmosphere according to claim 3, characterized in that, The heating rate of the electric kiln during the firing process described in step 3 is 5℃ / min.

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