Coating classification: Kaolin

Core tip: Introduction: Kaolin is an important inorganic non-metallic mineral with many excellent physical, chemical and mechanical properties Kaolin has been widely used in many fields, such as ceramics, electronics, paper-making, rubber, plastics, enamel, petrochemical industry, coating, ink, optical glass, chemical fiber, grinding wheel, construction coating, chemical fertilizer, pesticide carrier and refractory, etc Kaolin is mainly composed of small flake, tubular, laminated and other kaolinite cluster minerals (kaolinite, dickite, perlite, halloysite, etc.) less than 2 microns, Paint knowledge | precautions for wall paint color selection Recommended introduction: when painting the wall, the owner sometimes has difficulty in choosing what color of the wall paint to paint In fact, there is no ugly color in the wall paint, only the disharmonious color matching The use of wall color contains the knowledge of health Too strong color will stimulate people's perception, make people have a sense of fidgety, affect people's mental health Grasp the basic principles of wall color and paint a colorful space 1、 Wall paint color selection notice 1 Light color is generally used for the top surface Light colors make people feel light, dark colors make people feel heavy Usually, the treatment of rooms is from top to bottom, from shallow to deep For example, the ceiling and walls of rooms are white and Introduction: Kaolin is an important inorganic non-metallic mineral with many excellent physical, chemical and mechanical properties Kaolin has been widely used in many fields, such as ceramics, electronics, paper-making, rubber, plastics, enamel, petrochemical industry, coating, ink, optical glass, chemical fiber, grinding wheel, construction coating, chemical fertilizer, pesticide carrier and refractory, etc Kaolin is mainly composed of small flake, tubular, laminated and other kaolinite cluster minerals (kaolinite, dickite, perlite, halloysite, etc.) less than 2 microns The ideal chemical formula is al2o3-2sio2-2h2o Its main mineral composition is kaolinite and polyhydrokaolinite In addition to Gaoling cluster minerals, there are other minerals such as montmorillonite, illite, pyrophyllite, quartz and feldspar Associated There are a lot of Al2O3, SiO2, Fe2O3, TiO2, K2O, Na2O, Cao and MgO in the chemical composition of kaolin The pure kaolin is characterized by high whiteness, soft quality, easy dispersion and suspension in water, good plasticity, high cohesiveness, excellent electrical insulation, good acid resistance, low cation exchange capacity, good fire resistance and other physical and chemical properties Performance characteristics: ① because of its high refractive index of hexagonal crystal structure, the contrast index (covering power) of the coating film is greatly improved and excellent color ductility is provided; ② the flat nature of kaolin can provide a good balance between the fluidity and leveling of the coating Flat particles also tend to be arranged in parallel on the surface of the film, which can effectively prevent the penetration of water and improve the washability and anti pollution of the film For sticky film, flat particles can improve the compressive viscosity of the coating; ③ kaolin is hydrophilic, so it is easy to disperse, with small particle bulk density and good suspension performance; ④ It has a narrow distribution range of colloidal particles, tends to keep the viscosity of the paint unchanged, and can provide the rheological and thixotropic properties (high shear high flow and low shear low flow) that meet the requirements, so the film is relatively full, and can improve the defects of floating color and blooming of the pigment; ⑤ Strong chemical inertness, small optical axis angle and high crystal arrangement order will significantly increase the UV shielding ability of the coating Production process: the optional calcining equipment types for low temperature calcination are quick dehydrator, reverse flame kiln and continuous pusher kiln ① The calcination industry of the rapid dehydrator can be divided into two steps The first step is calcination at about 600 ℃ The high temperature hot air generated by the air preheater chamber enters the vortex, forming a rotating upward hot gas flow The extremely fine material is injected into the injection entrance from the upper and lower materials, dispersed by injector or sprayer, and enters the conical reaction chamber in the countercurrent direction The hot air enters by rotating at an average speed of 50-150 M / s from the nozzle with the minimum diameter at the lower part The calcined material is discharged from the end with the maximum diameter at the upper part, and then separated and collected by the cyclone dust collector The amorphous calcined kaolin can also be calcined in the second step The calcination temperature is above the transition temperature of the higher territory, i.e the starting temperature of exothermic reaction of kaolin is 900-1000 ℃ ② According to the shape of firing chamber, there are two kinds of inverted kiln: Circular kiln and rectangular kiln Their structure and working principle are basically the same Advantages: the volume of the kiln chamber varies widely (1-150 m3), the firing system is flexible, the operation and management are simple, and the production technology is easy to master ③ This is a continuous kiln This kind of kiln is compact in structure, small in area, simple in equipment, low in investment and fast in production, which can meet the domestic production requirements Due to the small loading surface of the kiln, the temperature difference in the kiln is generally small, and the product firing quality is uniform The utility model has the advantages of high heat utilization rate, convenient operation and management, and the calcination temperature is below 1000 ℃ The structure of this kind of kiln can be divided into single channel and double channel open flame type and flameproof type It uses coal and oil as its heat source and adopts flame-proof type Gas and electricity are used as heat sources and open flame type is used The equipment used for high temperature calcination is rotary furnace and kiln car tunnel kiln ① The gas from the continuous rotary furnace enters the calciner through the combustion chamber in a countercurrent way, the feed in the furnace enters from the flue gas outlet, the calcined material is discharged from the flue gas inlet, and the waste gas is discharged through the flue gas at the other end of the calciner In the process of calcination, the heat is transferred to kaolin and shell when the combustion gas and material convection, and then the shell radiates to kaolin The calcination temperature of rotary kiln is as high as 1500 ℃, at this time, kaolin can be converted into clay clinker ② Kiln car tunnel kiln this kind of kiln is connected with each other from front to back, on which is paved with refractory kiln car The moving kiln bottom is formed by moving forward along the kiln bottom track by the pusher Kaolin brick or casserole with blanks are stacked on the kiln car platform, moved with the kiln car, preheated, fired and cooled before going out of the kiln Home of coatings is specialized in coatings, diatom mud, paint coating, coating technology, fire retardant coating news and coating, diatom mud, paint coating, coating technology, fire retardant coating decoration knowledge and decoration renderings,