The minerals on the earth are mainly divided into three types: energy minerals, metal minerals and non-metallic minerals. Kaolin is an important non-metallic mineral, with mica, quartz and calcium carbonate become four non-technical minerals. China is the first country to discover and use kaolin in the world. The white pottery that appeared in the Shang Dynasty 3000 years ago was made of kaolin. Now the word kaolin is named after a kind of white clay that can be made from Gaoling Village in the eastern suburbs of Jingdezhen.
Kaolin, also known as kaolin, porcelain clay, is a clay mineral. The ideal chemical formula of kaolin, Al203•2Si02•2H20, is composed of clay minerals and non-clay minerals. The former mainly includes kaolin, ground stone, pearl pottery, kaolinite and jellyfish. The latter are mainly quartz, feldspar, mica and a small amount of heavy minerals and some spontaneous and secondary minerals. The pure kaolin is white, generally contains impurities, grayish white or light yellow, density between 2.56-2.6g/cm3, melting point is about 1785 °C, soft texture, less plasticity. Easy to disperse in water or solution, it has a slippery feel and has earthy taste. The chemical composition of kaolin contains a large amount of Al203, SiO2 and a small amount of Fe2O3, TiO2 and trace amounts of K2O, Na2O, CaO and MgO.
Glass fiber is a new functional material and structural material in inorganic non-metallic materials. It is widely used in high-tech industries such as electronics, communication, nuclear energy, aviation, aerospace, weapons, ship and marine development, genetic engineering, etc., and it is indispensable in China in the 21st century. Sustainable high-tech materials. According to foreign reports, glass fiber enterprises in Europe, America and Taiwan use high-strength and electronic grade glass fiber with good quality kaolin instead of pyrophyllite as raw material for glass fiber. The product quality is good. The role of kaolin in ceramics is to introduce Al2O3, which is beneficial to the formation of mullite, and improves its chemical stability and sintering strength. In the firing, kaolin decomposes to form mullite, which forms the main framework of the strength of the green body and prevents the product from being formed. The deformation makes the firing temperature wider, and the blank has a certain whiteness. At the same time, kaolin has two properties of plasticity, cohesiveness, Suspension and bonding, which gives good formability to porcelain clay and enamel, which makes ceramic mud favorable for car body and grouting, and is easy to form.
Ceramics not only have strict requirements on kaolin plasticity, bonding, drying shrinkage, drying strength, sintering shrinkage, sintering properties, refractoriness and whiteness after burning, but also involve chemical properties, especially iron, titanium, copper, chromium, The presence of a coloring element such as manganese reduces the whiteness after burning and produces spots. The grain size requirement for kaolin is generally as fine as possible, so that the porcelain clay has good plasticity and drying strength, but for the casting process requiring rapid casting, accelerated grouting speed and dewatering speed, the particle size of the ingredients needs to be increased. In addition, the difference in the degree of crystallization of kaolinite in kaolin will also significantly affect the process performance of the kiln. The degree of crystallization is good, the plasticity, the bonding ability is low, the drying shrinkage is small, the sintering temperature is high, and the impurity content is also reduced; otherwise, The plasticity is high, the drying shrinkage is large, the sintering temperature is low, and the corresponding impurity content is also high. The finished kaolin produced by ultrafine grinding has a particle size of 325 mesh to 3000 mesh, which meets the requirements of ceramic products.
For the application of kaolin to the processing of glass fiber, it needs to be processed to about 2000 mesh, and it is necessary to use the micro-grinding equipment produced by Shanghai Zenith Mining Engineering Co., Ltd. The Shanghai Zenith Mine has a site for processing kaolin in many countries. For example, there are two XZM236 in Karachi, Pakistan, and three ZXM224 in Udaipur, India. Micro-grinding is widely used in a variety of non-flammable and explosive materials with a Mohs hardness of 7 or less, such as limestone, calcite, dolomite, kaolin, mica, barite, fluorite, potassium carbonate. Its applications have spread throughout the paint, paper, pigments, rubber, plastics, fillers, cosmetics, chemical products and many other industries.
Compared with traditional jet mill and ball mill, micro-grinding has technical advantages.