Kaolinite English name kaolinite, 2Al2O3.4SiO2.4H2O oxide form. Mainly feldspar And other Silicate minerals The product of natural alteration, is a kind of water Aluminum silicate . Kaolinite or dense or loose bulk, usually white, if the impurities is beige.
Kaolinite pure white, other colors can be dyed due to impurities. Collection of dim or a wax. have eminent cleavage The hardness of 2.0~3.5, relative density 2.60~2.63. Dense block with rough, with water when dry, wet malleable, but not water expansion.
Kaolinite subgroup including kaolinite, dickite and nacrite three multi type. The theoretical structure of their Al[Si4O10] (OH) 8, no water layer.

kaolinite brief introduction

 kaolinite kaolinite
Including Dickite , Pearlstone and Halloysite And similar components but Amorphous The Allophane Therefore, they belong to the type of clay minerals. They always exist in tiny microcrystalline or cryptocrystalline state, and that massive or earthy aggregate production.
Belong to the kaolinite clay mineral, its chemical composition is Al4[Si4O10] (OH) 8. The crystal belongs to the triclinic three Layered structure Silicate minerals. A Adiagnostic Dispersion, powder, loose block Aggregate . White, light gray, light green, yellow, red and other colors. Streak White, Earthy Luster . Mohs Scale of Mineral Hardness 2-2.5, proportion 2.6-2.63. Water absorbent The water is strong, and Plasticity . Sticky tongue, dry lumps with rough feeling.
The theory of composition (wB%): feldspar mineral weathering and. 4K[AlSi3O8]+4H2O+2CO2 = Al4[Si4O10] (OH) 8+8SiO2+2K2CO3. In addition, in the low temperature hydrothermal alteration, can also form kaolinite (generally low temperature and acidic conditions). Al2O3 39.5%, SiO2 46.5%, H2O 14%. for Eight face In Al. Al and Fe instead of Si number is very low. alkali and Alkaline-earth metal The elements are mechanical mixing materials. Because lattice The edge of chemical bonds is not balanced, can cause a small amount of cation Exchange.
 kaolinite kaolinite
Kaolinite is composed of kaolin The main mineral In common. Magmatite and metamorphic rock The Weathering crust In.
Kaolinite is widely distributed, mainly by the rich aluminum silicate in acidic medium, the Weathering The product or low temperature hydrothermal metasomatic change. In the low temperature hydrothermal process, when the content of CO2 in acidic aqueous solution containing no alkali The aluminum silicate and silicate When can cause KAOLINIZATION, the formation of kaolinite in feldspar Mica, Topaz Into the illusion.
Famous origin are Jiangxi, Jingdezhen Chinese kaolinite Jiangsu Suzhou, Hebei Tangshan, Hunan Liling Etc.. The rest of the world famous origin of British Cornwall and Devon, France, the United States such as Georgia irie. Kaolinite is the main raw material for ceramics, in other industries are widely used.
Gaoling stone weathering or deposition The role of a kaolin But, kaolin Is the production of ceramic raw materials. In addition, kaolin can be used as chemical packing, Refractory material Building materials, etc., is widely used. Chinese Jiangxi Jingdezhen There is one Gaoling Village Here is rich in kaolin, named. At the end of the Ming Dynasty in Jingdezhen kaolin mining village of the mine, after the German geologist richthofen According to the "Kaolin", kaolin mineralogy introduced the world community.

kaolinite Morphological structure

 kaolinite kaolinite
The three belongs to triclinic, a0=0.514nm, b0=0.893nm, c0=0.737nm, =91.8 alpha, beta gamma =104.7, =90, Z=1. The structure is TO, i.e. Structure unit A layer of silicon oxygen tetrahedron and "aluminum hydroxide stone" eight face plate structure link layer formed along the c axis and stacking. There are no interlayer cations or water molecules, strong hydrogen bonds (O-OH=0.289nm) to strengthen the connection between the structure layer.
In the actual structure, due to the deformation of aluminum hydroxide stone tablets and size (a0=0.506nm, b0=0.862nm) and silica tetrahedron The size of the film (a0=0.514nm, b0=0.893nm) is not exactly the same. Therefore, in the tetrahedral sheet must be tetrahedral after mild relative rotation and warpage and deformation of the aluminum hydroxide can adapt to the stone tablets.
Packing structure of kaolinite layer is adjacent to the structure layer along the a axis staggered 1/3a, and there are different angles of rotation. So, there are many different types of kaolinite. The most common type is 1Tc, followed by Dickite (dickite) and Pearlstone (nacrite), and 1M type rare. Generally refers to the 1Tc of kaolinite kaolinite.
The layer structure of kaolinite in the stacking process,
 Schematic diagram of the structure of kaolinite Schematic diagram of the structure of kaolinite
If the interlayer is filled with a layer of water molecules, forming halloysite Al4[Si4O10] (OH) 8 - 4H2O. In halloysite crystal structure In the Interlayer water The presence of the molecules, destruction of the original strong hydrogen bond The link system, silica Tetrahedral sheet The difference between oxygen and aluminum sheet by curling stone can be overcome. To make a structural unit of halloysite tetrahedral sheet outside the home and eight pieces of the surface layer structure of crimp engagement appears. Therefore, the structure of halloysite can be regarded as the kaolinite structure of water molecule layers separated by c0=1.01nm.
A massive or aphanitic earthy aggregate. Electron microscope Under the six plate, euhedral subhedral or flaky crystal form. Flake size is generally 0.2~5 ~ m, the thickness of 0.05~2 M. Highly ordered kaolinite 2M1 scale up to 0.1~ 0.5mm, the highest degree of order 2M2 kaolinite scales up to 5mm. Aggregate usually is flaky, scaly, radial etc..
Polarizing microscope: colorless, flake. Two axis (-) 2V=10~57 316LVM. Np=1.560~1.570, Nm=1.559, ~1.569, Np=1.533~1.565.

kaolinite Identification of characteristics

Dense soil blocks easily crumbled into powder, sticky tongue, add water plasticity, loss of water in a closed tube after heating. After burning and Cobalt nitrate A blue reaction (Al). Kaolinite and their type available X ray Analysis of diffraction and thermal distinguish. Different points of halloysite and kaolinite is in the range of 100~200 DEG C has obvious endothermic effect, which is equivalent to remove the interlayer water.

kaolinite The main application

kaolinite Industrial application

kaolinite clay Except for the ceramic raw materials, papermaking raw materials, rubber and plastics filler , Refractory material Such as raw materials, but also can be used to synthesize zeolite molecular sieve And the daily chemical products packing etc..
The development and utilization of kaolin, for Jingdezhen The rapid development of ceramic industry has laid a solid foundation, played a significant role in the development of the world revolution of ceramic technology. With the first single (a ceramic porcelain manufacturing raw materials using porcelain stone) to two yuan (two kinds of porcelain formula later manufacturing raw materials use porcelain stone and kaolin), porcelain craft is excellent. As the ceramic raw materials to kaolin, greatly promoted the quality of ceramic products and improve the technological level, to promote the development of ceramics.
Kaolinite has high whiteness and brightness, soft, strong water absorption, easy dispersion, good plasticity is suspended in the water and high adhesion, acid and alkali resistance, good electrical insulation, strong Ion adsorption And weak Cation exchange And sintering and high refractoriness, good performance. China has very abundant kaolinite, only Guangdong has 6 large kaolin deposit. Nano kaolinite Shi Ke used in the manufacture of paints, paper, textiles, cosmetics, environmental protection, high temperature refractory materials. At present, China's use of paint is mostly traditional organic chemistry Solvent type coating There, toxic, harmful to human health, and scrub resistance difference. Nano kaolinite coating particles developed by nanotechnology fine, high whiteness, good dispersion, chemical stability Good washability can be increased by 1000 times, non-toxic harmless, self-cleaning, stain resistance, aging resistance, air permeability, sterilization and mildew proof ability, rheology, brushing, good elasticity (can prevent cracks), delicate texture. In addition, the special nano coating can also be made for different purposes, such as anti UV coating, stealth coatings etc.. The present study in our school nanotechnology Institute has completed the laboratory research work of nano kaolinite, mature production technology, the pilot has been completed.

kaolinite Technical characteristics

Nano kaolinite coating fine particles, high whiteness, good dispersibility, good chemical stability, abrasion resistance can be increased by 1000 times. Nano kaolinite also can be used in the manufacture of paper making, textile, environmental protection, high-end cosmetics, high temperature refractory materials. Nano coating, ceramics, paper, coating The research and production, national patent, and in cooperation with foreign enterprises, the company set up Limited by Share Ltd, products to the domestic and foreign markets, creating significant economic benefits.

kaolinite kaolinite clay

Kaolinite clay also called kaolin clay, commonly known as """. Composed of more than 90% of the content of kaolinite. Kaolin is an important non-metallic mineral, and quartz, mica, calcium carbonate and known as the four major non metallic minerals. A kind of kaolinite or kaolin. Halloysite As the main component, texture pure clay, is first found in Chinese near Jingdezhen Gaoling village named. Small flake, tubular, laminated and kaolinite minerals mainly consist of clusters of less than 2 microns (kaolinite, dickite, nacrite, halloysite etc.), chemical formula and ideal for AL2O3-2SiO2-2H2O, the main mineral is kaolinite kaolinite and kaolinite mineral water, in addition to the cluster, and montmorillonite , Illite , Pyrophillite , quartz Other minerals such as feldspar and associated. The chemical composition of kaolin contains a large number of AL2O3, SiO2 and a small amount of Fe2O3, TiO2, Na2O, K2O and trace CaO and MgO etc..

kaolinite Related information

Guanyintu was hungry as food to eat during the great famine, eat temporarily lifted hunger Sense. Chongzhen Three years (1630) in Shaanxi as the great famine, Shaanxi Mamaocai In " Chen Shu by hunger "Said the people of Shaanxi can only fill the stomach to eat guanyintu. People's Republic of China in 1960s three years of famine during the period there are a lot of people eat guanyintu.
But not guanyintu organic Food, containing a large number of alumina That can not be digested, although eat not hungry, eat a small amount not fatal, but because there is no nutrition, eat for a long time people will die from malnutrition. In addition, eat guanyintu have abdominal distension, foot swelling, hard stool and other symptoms. Swell plus guanyintu water, has been beaten to death after eating guanyintu.