White mud: it is a kind of mixed kaolin, belonging to non-metallic minerals. The main chemical composition is probably: SiO2Al2O3Fe2O3.
Black mud: black mud, its color is like ink, like the vast sky at night, unfathomable, with a little gold sand. Kiln temperature: about 1 140℃ shrinkage: about 14%. Mud: raw materials are relatively loose, so we must be careful in processing and molding. Difficulty: easy to jump sand and wrinkle, medium firing rate. Features: Many players mistakenly think that satin mud will "spit black". The reason for this misunderstanding is that the kilns in the past were all low-temperature kilns, and satin mud was high-temperature mud (the general firing temperature was about1175 ~1180).
Epitaxy: Ceramic raw materials include kaolin, clay, porcelain stone, porcelain clay, colorant, blue and white materials, lime glaze, lime alkali glaze, etc. Named after Gaoling Village. Its chemical experimental formula is: Al203 2Si02 2H20, with a weight percentage of 39.50%.
Most utensils are made of lime glaze.
The main components of calcium-alkali glaze are fluxing substances calcium oxide and alkali metal oxides, such as potassium oxide (K2o) and sodium oxide (Na20). It is characterized by high viscosity at high temperature, difficult glaze flow and thick glaze application. In the process of high temperature firing, the air in the glaze will float out of the glaze surface, forming many small bubbles in the glaze, leaving a certain number of undissolved timely particles and a large number of anorthite crystals in the glaze. These small bubbles, timely particles and the crystallization of anorthite scatter the light entering the glaze layer, thus making the glaze layer opaque and opaque, resulting in the visual effect of being moist as jade. The invention and application of calcium-alkali glaze is a great progress of traditional celadon technology. Lime-alkali glaze appeared in Ruyao celadon in the Northern Song Dynasty. Longquan kiln porcelain was widely used in the Southern Song Dynasty.