The direct precipitation method is to add a precipitant to a soluble salt solution containing one or more particles, generate a precipitate under certain conditions and precipitate out of the solution, and obtain the product through thermal decomposition. For example, use MgCl2·6H2O and NH3·H2O as raw materials, add the precipitant NH3·H2O to the MgCl2·6H2O solution under a certain temperature and sufficient stirring conditions, and after filtering, washing, drying, and calcining, nano-magnesium oxide is obtained. The average The particle size is 62nm. This method has a simple process, low requirements on equipment technology, high product purity, good stoichiometry, and low preparation cost, but the product has larger particle size and wider particle size distribution. Using NH3·H2O and brine as raw materials, anhydrous ethanol as the reaction medium, and using a supercritical drying method to prepare 50-100nm nanometer magnesium oxide products.
Nanomagnesium oxide is a new type of high-functional fine inorganic material. It generally refers to a collection of nanoparticles with a particle size between 1 and 2000nm. Due to its miniaturization, it has thermal, light and electrical properties different from those of the bulk material. , mechanics and chemistry and other special functions. Nano-magnesium oxide is compounded with polymers or other materials and has good microwave absorption properties. Using ultra-fine powdered magnesium oxide, low-temperature sintering can be achieved without the use of sintering aids to produce highly dense fine-grained ceramics, which are expected to be developed into materials used under harsh conditions such as high temperature and high corrosion. Nanomagnesium oxide can also be used as a sintering aid and stabilizer for other nanoparticles such as zirconia, alumina, and iron oxide to obtain high-quality nanophase ceramics, as well as auxiliary materials for various electronic materials.
Highly active magnesium oxide generally refers to magnesium oxide with an iodine absorption value of 120-180mg/g. It is mainly used as an accelerator and activator for chloroprene rubber, butyl rubber, nitrile rubber and fluorine rubber. It is also used as an accelerator and activator for adhesives, plastics, and paints. , paper filler. Nano-active magnesium oxide has strong adsorption and high surface chemical activity. It can be used as a dissociation adsorbent to adsorb toxic chemicals.