Dense or loose lumps, white and light gray in appearance. When it is contaminated by other impurities, it can be dark brown, pink, beige, etc., with a slippery feel. It is easy to knead into powder by hand. After calcination, the color is white and the refractoriness is high. It is an excellent raw material for porcelain.
The firing process of ceramic cups:
1. Clay practice: Porcelain stone is taken from the mining area, pounded with water, elutriated to remove impurities, and precipitated into brick-like mud. Then mix the mud with water to remove the slag, rub it with your hands or step on it with your feet to squeeze out the air in the mud and make the water in the mud even.
2. Drawing the billet: Throw the mudball at the center of the turntable of the potter's wheel, and draw the rough shape of the billet by bending and stretching.
3. The impression of the blank: the appearance of the impression is to be rotated according to the arc inside the blank, and the semi-dry blank is placed on the mold, and the outer wall of the blank is evenly pressed, and then demolded.
4. Rigid billet: Lay the billet on the sharp bucket of the wheel car, turn the turntable, and use a knife to turn the billet to make the billet thickness appropriate and the surface and the inside smooth. This is a process with high technical requirements.
5. Exposure of the billet: Place the processed billet on a wooden rack for drying.
6. Carving: Use bamboo, bone, or iron knives to carve patterns on the dried or semi-dried body.
7. Glazing: Ordinary round mouth adopts dipping glaze (dip the blank into the glaze basin, and immediately raise it when the mouth is flush with the glaze surface) or glaze (pour the glaze slurry into the blank and shake to make the top, bottom, left, and right glaze evenly, and then quickly Pour out the excess glaze slurry), cut ware (relative to "round ware", "round ware" refers to round utensils that are formed by the drawing method, such as bowls, plates, dishes, etc. The molding process is more complicated. Such as bottles, statues, pots, pots, etc., are called "cutting devices") or large round wares with blowing glaze (the method is to cover the bamboo tube with fine yarn, dip in the glaze, and blow with the mouth. Repeat this many times, the thickness of the blank surface can be obtained. Uniform glaze layer).
8. Kiln: The time course is about one day and night, and the temperature is about 1300℃. Build the door of the kiln first, ignite the kiln. The fuel is pine firewood, guide the piling technology, measure the fire time, grasp the temperature change of the kiln, and decide the ceasefire time.
9. Colored glaze: On-glaze colors such as multicolored, Famille rose, etc., are used to draw patterns and fill colors on the glaze surface of the fired porcelain, and then burn it in a red furnace at a low temperature, at a temperature of about 700 ℃-800 ℃. In addition, before firing the kiln, paint on the green body, such as blue and white, red in glaze, etc., is called red in glaze, which is characterized by the color that will never fade under the high-temperature glaze.
