The present invention relates to a method for preparing kiln-changing glaze, especially a method for preparing secondary phase-separated Dahong kiln-changing glaze. Kiln-changing glaze is a type of kiln-changing glaze. Its patterns and colors are not manually drawn, but formed naturally through the "kiln-changing" process. It is an unpredictable artistic ceramic glaze, mainly used for decoration of ceramic crafts. Our country's kiln-changing glaze has a long history. The phenomenon of kiln-changing glaze was discovered as early as the Tang Dynasty. In the Song, Yuan, Ming, Qing and various periods of modern China, kiln-changing glaze technology and products emerged in endlessly, which won the hearts of the people, especially art collectors. love. There are many patents related to kiln variable glaze. For example, CN1962557 discloses a ceramic red kiln variable glaze and its application method. The ceramic red kiln variable glaze includes red glaze and titanium white glaze. The chemical composition of the red glaze is SiO2 of 53-58. , Al2O3 is 10-11, K2O is 4-4. 5, Na2O is 1-1. 2, MgO is 0. 1-0. 12, CaO is 11. 5-12. 5, ZnO is 5-7, Fe2O3 The chemical composition of the titanium white glaze is 0.5-1, the red wrapping color is 9_11, the chemical composition of the titanium white glaze is Si02, 52_56, Al2O3, 10-11, K20, 4.5-5, and Na2O, 1.3-1.5. CaO is 9_10, TiO2 is 11_13, Ba0 is 5-6, P2O5 is 0.5-0.7, MgO is: 0.4-0.6, Fe2O3 is 0.23-0.28, its application method is first Apply titanium white glaze to the ceramic body that has been bisque-fired at 950°C, then apply the red glaze, and finally fire it at 1230°C -1250°C to obtain red kiln-turned ceramics with different colors; another example is CN200510034903 . 2 Discloses a manufacturing method of red catastrophic Tianmu ceramics and the ceramic glaze used therein, as well as a method of firing red catastrophic Tianmu ceramics using the ceramic glaze. The ceramic glaze mainly contains K2O and/or Na20, A1203, SiO2 , MgO, Fe2O3gt; P2O5, CaO and B2O3, apply the above ceramic glaze on the ceramic green body or plain body, glaze firing, in an oxidizing atmosphere, the temperature rises to 120-180°C per hour, 1050-115 (TC per hour) Raise the temperature to 30-70°C, keep it at 1200-1300°C for 10-120 minutes, stop the fire, and cool naturally to obtain a ceramic product with a red blaze. The ceramic product produced by this invention has a dark brown base glaze and red or yellow crystal spots. It is surrounded by a golden halo with mirror effect and metallic luster. The luminous position moves with the change of the viewing angle, which is dazzling. The firing process is easy to master. The main reason for the kiln change effect is the glaze. Composition, firing system and firing environment. The glaze composition is an internal factor, while the firing system and firing environment are external factors. Under appropriate internal and external conditions, the molten glaze produces phase separation, and then crystallizes and Color development and other processes form ever-changing kiln-transformed glazes. There are the following reports on phase-separated kiln-transformed glazes
The 2nd issue of "Ceramics" in 1994 reported that the main component phase of ceramic glazes is the glass phase, which is closely related to the glass body. To a large extent, they have similar properties, so the required phase separation (kiln transformation) effect can also be achieved by finding a suitable composition system and firing system (thermal history). This is the theoretical basis for the application of phase separation principles in ceramic glazes. The main purpose of the application of phase separation principle in ceramic glaze is to achieve the appearance of kiln transformation effect that can be seen by the naked eye through specific internal phase separation, so it is deeper than the phase separation in glass. When the glaze glass undergoes liquid phase separation for the first time in the immiscible zone, two phases with different viscosities are produced, which makes it difficult for the concentration of the entire system to be uniform. The system is in an unbalanced state, and it is possible to proceed in some areas. The second level of phase separation leads to a more complex internal structure, giving the glaze a more special artistic look and feel from a macro perspective.
The 10th issue of "Foshan Ceramics" in 2009 reported the phase separation mechanism of high-temperature melt and its application in kiln glaze. It discussed the basic concept of liquid phase separation of high-temperature melt, as well as the mechanism and scope of phase separation, and based on this Based on this, we conducted a more in-depth study on the application of split-phase theory in ceramic kiln glaze transformation, which provided a new development path for ceramic art glazes.
The 7th issue of "Chinese Ceramics" in 2011 reported on the research on imitation of Junhong phase-separated kiln variable glaze. Modern porcelain making technology was adopted, and ceramic raw materials produced near Jingdezhen were selected and fired in shuttle kilns. The imitation of Jun-red phase-separated kiln-changing glaze basically achieves the effect of different shades of cyan-blue flow patterns and purple-red. In the experiment, with the help of colorimeter, SEM and other means, the effects of the Si/Al molar ratio, the addition amount of phase separation promoter P205 and the content of colored oxides CuO and Fe203 on the color of Jun red phase-separated kiln glaze were discussed. The 2nd issue of "Foshan Ceramics" in 1999 reported the correlation analysis between the maturation temperature and chemical composition of enamel glaze. This article uses the structure of glaze glass as a guide, combined with the fluxing ability of various oxides to glaze at high temperatures, based on eight experiments. Based on the test results and the maturation temperatures of six manufacturers' formulas, the relationship between the maturation temperature and the chemical composition of the glaze was studied. The results of the correlation analysis proved that the chemical composition of the glaze has a high correlation with its maturity temperature, and an empirical formula for calculating the maturity temperature based on the chemical composition of the glaze was obtained. This formula is more accurate than the currently used formula. Spend.