What Is Kaolin Uses For
Kaolin was developed and utilized earlier and traditionally used in ceramics and refractories. Since 1980s, it has been developed and utilized on a large scale, and its application field has been gradually expanded.
Kaolin Uses In Ceramin Industry
In the ceramic industry, the application of kaolin is earlier than other industries, and the amount is also very large, usually accounting for about 20% to 30% of the formula. The role of kaolin in ceramics is to introduce Al2O3, which is conducive to the formation of mullite, and improves its chemical stability and sintering strength. During firing, kaolin decomposes to form mullite, forming the main frame of the green body strength, which can prevent the product from sintering. Deformation makes the firing temperature wider and the green body has a certain degree of whiteness. At the same time, kaolin has certain plasticity, cohesiveness, suspension and binding ability, which endows porcelain clay and enamel with good formability, which makes the ceramic slime beneficial to car blanks and grouting, and is easy to form. If used in wires, it can increase insulation and reduce its dielectric loss.
Ceramics not only have strict requirements on the plasticity, bonding, drying shrinkage, drying strength, sintering shrinkage, sintering properties, refractoriness and whiteness after firing of kaolin, but also involve chemical properties, especially iron, titanium, copper, chromium, The presence of color elements such as manganese reduces the whiteness after burning and produces spots. Therefore, the content of Fe2O3 is required to be in the range of 0.6% to 0.7%, and the content of TiO2 is lower than 0.5%, otherwise the translucency will be reduced. The presence of alkali elements will change the porosity, requiring (CaO MgO) <2% and potassium content less than 1.5%. The presence of sulfuric anhydride (SO3) will cause defects such as foaming, cavities and cracking in ceramic products, and it is suitable to be less than 1%. Loss on ignition requirements <15%. The particle size requirement of kaolin is generally as fine as possible, so that the clay has good plasticity and dry strength, but for the casting process that requires rapid casting, accelerated grouting speed and dehydration 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 porcelain blank. If the degree of crystallization is good, the plasticity and bonding ability will be low, the drying shrinkage will be small, the sintering temperature will be high, and the impurity content will also be reduced. Its plasticity is high, the drying shrinkage is large, the sintering temperature is low, and the corresponding impurity content is also high.
- Paper Industry: coatings or pigments for paper fillers, coated paper, coated paperboard, coated paper, etc
- Coating Industry: fillers and pigments for coatings
- Refractory And Cement: crucible, refractory brick, sagger, refractory mud, white cement for optical glass and glass fiber, etc
- Plastic, Rubber, Cable: plastic, rubber filler, cable insulation filler
- Petroleum And Chemical Industry: petroleum cracking catalyst carrier, molecular sieve and adsorbent