Supplementary knowledge
Clay is a kind of cohesive soil, which contains little sand, and water is not easy to pass through, so it has good plasticity.
Generally speaking, clay is formed after silicate minerals are weathered on the earth's surface. Generally, it is weathered in situ, with large particles and composition close to the original stone, which is called primary clay or primary clay. This kind of clay is mainly composed of silica and alumina, which is white and fire-resistant, and is the main raw material for preparing porcelain clay.
Clay, also known as clay, has very small particles (
Clay is generally formed after aluminosilicate minerals are weathered on the earth's surface. But some diagenesis can also produce clay. The appearance of clay in these processes can be used as a sign of the progress of diagenesis.
Clay is an important mineral raw material. It consists of various hydrated silicates and a certain amount of alumina, alkali metal oxides and alkaline earth metal oxides, and contains impurities such as feldspar, mica, sulfate, sulfide and carbonate.
Clay minerals are fine, often in the range of colloid size, crystalline or amorphous, most of them are flaky, and a few are tubular and rod-shaped.
Clay minerals are plastic when wetted by water, can be deformed under small pressure and can remain unchanged for a long time, and have large specific surface area and negatively charged particles, so they have good physical adsorption and surface chemical activity, and have the ability to exchange with other cations.
Clay is generally formed by weathering silicate minerals on the earth's surface. Generally, it is called primary clay or primary clay, which is weathered in situ, with large particles and composition close to the original stone. This kind of clay is mainly composed of silica and alumina, which is white and fire-resistant, and is the main raw material for preparing porcelain clay.
Clay continues to weather and become young, and then it is transported by running water and wind, and a thick layer of clay is formed downstream, which is called secondary clay or secondary clay. Because of pollution, this kind of clay contains many metal oxides, dark color and low fire resistance. Because of its good viscosity and plasticity, it is the main raw material for preparing clay.