Ceramic not only on kaolin clay plasticity, combination, drying shrinkage, drying strength, sintering shrinkage, sintering properties, refractoriness and sintering whiteness has strict requirements, but also relates to the chemical properties, especially iron, titanium, copper, chromium, manganese and other coloring elements exist, so that after firing whiteness lower spots.The size requirements for kaolin is as small as possible to make porcelain clay plasticity and drying has good strength, but the requirement of rapid casting process, casting speed up the grouting speed and dewatering speed, to improve the granularity of ingredients. In addition, differences in the degree of crystallization of kaolinite in kaolin, will also significantly affect the process performance of ceramic, degree of crystallization is good, plasticity, binding ability is low, small drying shrinkage, high sintering temperature, the impurity content is reduced; on the contrary, the plasticity is high, dry shrinkage, sintering temperature is the corresponding low impurity content is high. In the old society and the difficult period of three years, the poor in lean or famine years, often eat guanyintu live; the soil can eat, but can not be digested, after eating to eat a small amount of stool, abdominal distension, not fatal; although not hungry, but because there is no nutrition, people still die. The famine caused by eating guanyintu abdominal distention, not defecation, suffocated people too many to count.
Kaolin has become the mineral material necessary for papermaking, ceramics, rubber, chemicals, coatings, pharmaceuticals and national defense.Ceramic industry is the earliest and larger amount of kaolin. The general dosage is 20% to 30% of the formula. The role of kaolin in the ceramic is conducive to the introduction of Al2O3, mullite, the chemical stability and sintering strength during sintering kaolin decomposition of mullite, the main frame form body strength, can prevent the deformation of the product, the firing temperature becomes wide, can make the body with whiteness some. At the same time, kaolin has a certain degree of plasticity, adhesion, suspension and binding capacity, given the enamel porcelain clay, good formability, the ceramic clay for car billet and grouting, easy forming. If used in an electric wire, insulation can be increased and dielectric loss is reduced.
Because the calcined clay oil absorption value is relatively high, so the cosmetics industry recommends the use of ultrafine and high pure water wash soil, strict attention purity and heavy metal content of kaolin, these two aspects report report analysis and detection of heavy metals and chemical products, through the data report and compare its cosmetic requirements can be judged. Pharmaceutical industry bigger user base for butyl rubber plug industry, can use 1250 or so of calcined soil, this is more commonly used, usually as long as the heavy metal test qualified can use. The above two industries use kaolin price difference is quite big, the cosmetics class import product approximately RMB6 yuan /kg, the medicine class RMB2.2 yuan /kg.
