Know "clay"

Clay is an important mineral raw material. It is composed of a variety of hydrated silicates and certain amounts of alumina, alkali metal oxides, and alkaline earth metal oxides, and contains impurities such as quartz, feldspar, mica and sulfates, sulfides, and carbonates. Clay minerals have small particles, often in the range of colloidal size, and they are crystalline or non-crystalline. Most of them are flaky and a few are tubular and rod-shaped. The clay mineral has plasticity when wetted with water, can be deformed under a relatively small pressure and can maintain its original shape for a long time, and the specific surface area is large, and the particles are negatively charged. Therefore, they have good physical adsorption and surface chemical activity, and have Other cations. The ability to exchange.

characteristic

Clay-containing soils are very easy to combine with water, minerals, and organic nutrients because clays with very small particles have a large relative surface and the polarity of their surface. In the production of clay has the characteristics of fertilizer retention and water retention, and it is called "a mess when wet, a knife when dry," and poor cultivability.

form

Clays are generally formed from silicate minerals that have weathered the surface of the earth. Generally weathered in situ, the particles are larger and the components are close to the original stone, which is called primary clay or primary clay. This clay is mainly composed of tin oxide and aluminum oxide, white and fire-resistant, and is the main raw material for preparation of china clay.

The clays continue to weather and become young, and then migrate through the flowing water and wind forces, forming a thick layer of clay in the downstream, called secondary or secondary clay. This clay is contaminated with more metal oxides, darker colors and lower refractoriness. Due to good adhesion and plasticity, it is the main raw material for the preparation of clay.

Kaolin clay is a soft clay mainly composed of kaolinite subgroup minerals. It is mainly composed of kaolinite minerals. In nature, the minerals that make up kaolin are clay minerals and non-clay minerals. The color is white, the maximum whiteness is greater than 95%, and the hardness is 1~4.

Minerals

Some clay minerals are:

Kaolinite: Al2O3.2SiO2.2H2O

Stone grease: Al2[(OH)4|Si2O5] * n H2O

Montmorillonite: (Al,Mg)2[(OH)2|Si4O10](Na,Ca)x * n H2O

Vermiculite: (Mg,Ca)0,31(H2O)n{Ti0,18Al0,03Fe(III)1,09Mg1,25[Si2,80Al1,20O10(OH)2]}

Illite: K0,65Al2,0Al0,65Si3,35O10(OH)2

Water Aluminium Stone: Al2O3.SiO2.2,5H2O

application

Clay made ceramics

Industrial clay minerals include kaolin, bentonite (mainly composed of montmorillonite), activated clay (undefined composition), and the like. Kaolin was first mined in Kaolin Village in Jiangxi Province to make ceramics. Bentonite began mining in the United States in Wyoming in 1888 and activated clay was first mined in Texas in the United States in 1906.

Cement

Cement after mixing with limestone

Various applications

Models in industry, model making and art. Artists use clay to make models, but also apply clay to directly shape artworks

Used as an ion exchanger in drinking water processing and other chemical processes

Kaolinite is a raw material for porcelain

Kaolinite also makes the surface of the paper particularly smooth and absorbs ink

Ceramics used as a barrier in construction and in soilless cultivation

Sealed landfill

Filling in the pigment and pharmaceutical industries

Used in catalytic converters