Method for preparing nano mullite

Abstract

The invention discloses a preparation method of nano-mullite, and comprises the following steps: (1) according to mullite podwer: sodium hydroxide and / or sodium carbonate, urea and water are mixed ina weight ratio of 1:0.2 to 1:0.1 to 0.5:4 to 10 and go through reaction for 2 to 12 hours; (2) then 1 to 3 portions of glacial acetic acid and 0.02 to 0.2 portion of anionic surfaceactive agent are added to go through reaction for 2 to 12 hours, the reacted mixture is filtered, rinsed and dried after reaction, and white powder solids are obtained; (3) the white powder obtained according to the step (2): dimethyl sulfoxide DMSO, the sodium carbonate and ampholytic surfactant are mixed in a weight ratio of 1:4 to 8:0.1 to 1:0.1 to 0.5 to go through reaction for 2 to 12 hours, the reacted mixture is filtered, rinsed and dried after reaction, and white powder solids are obtained. The nano-mullite needed is obtained after the white powder solids is baked and burned. The invention has raw material sources which are easily and widely obtained, mild reaction condition, low requirement for equipment, little pollution to environment and short reaction time.

Description

technical field [0001] The invention relates to a method for preparing mullite, in particular to a method for preparing nanoscale mullite. Background technique [0002] Mullite is the only stable compound in the alumina-silica binary system. It has a high melting point (1850 degrees Celsius) and has excellent fire resistance properties, such as low thermal conductivity and thermal expansion coefficient, high creep resistance and heat resistance. It is the material of choice for high-temperature structural materials, infrared transmission windows, microelectronic substrate materials and catalyst carriers. The important factor affecting its performance is mainly mullite crystals. Particle size and distribution, when the particle diameter is reduced to the nanometer level, not only the number of surface atoms will increase rapidly, but also the surface area and surface energy of the nanoparticles will increase rapidly, so nano-mullite has more attractive properties, for example...

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Problems solved by technology

[0003] At present, the commonly used mullite materials are artificial synthetic materials, which are mainly synthesized by high temperature reaction method (1700-1750°C) or electrofusion method. The disadvantages of these two methods are that the cost is too high, the reaction conditions are harsh, and the preparation process Complex, the particle size of the obtained mullite is in the range of microns

Reports on other methods include: In the microstructure characterization of mullite composite nanocrystals prepared from natural ore kaolin (Acta Silicate Sinica 2000, 2, 68-71), it was reported that the main crystal of mullite was synthesized by hydrothermal crystallization Composite nanocrystals of mullite phase; In the discussion on the preparation mechanism of mullite composite nanocrystals (IM & P Chemical Minerals and Processing 2005, 3, 10-13), it was also reported that calcined kaolin obtained nano-scale mollite after hydrothermal reaction. In the study of the application of nano-mullite powder in catalytic hydrogenation (Industrial Catalysis, 2003, 2, 33-35), it was reported that the sol-gel method was titrated by ammonia water from ethyl orthosilicate and aluminum nitrate , Supercritical drying and calcining to prepare nano-mullite. According to literature search, no ideal method for preparing nano-mullite has been found.

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