Nano Magnesium Oxide Preparation Process

This paper has reviewed the properties and application of nanometer magnesia. Both the progress in research and the synthesis of nanometer magnesia has been reconsidered. It puts emphasis on the reaction mechanism of precipitation method to prepare nanometer particles, and puts forward a new technics named " precipitation-transforming-method " .The essence of the experiment process has been studied through a series of designed experiment. In order to get the optimum processing conditions and the effects of various factor in preparation of nanometer magnesia and surface modification of prepared magnesia, monofactor method and multifactor orthogonalizing design method have been applied. The following has been obtained through lots of expriments: (1) The velocity of the initial stage of " precipition -transforming - method" is mainly influenced by the diffusion of CO32-,while that of the upper stage is equally influenced by both the diffusion of CO32- and the ionization of the Mg(OH)2. The phenomenon of precipitation transforming exists in the process. (2) The optimum processing conditions in preparation of nanometer magnesia: the reaction time is 20 min; the reaction temperature is 300C;the dosage of water is 200 ml;the modification reagent should be added to the reaction system in drops after 10 min; the calcination temperature is 6000C. The average diameter of the nanometer magnesia under the above conditions is 5.22nm. (3) The optimum processing conditions in the surface modification of nanometer magnesia : the modification temperature is 600C;the modification pH is about 5; the dosage of modification reagent is 10%. The value of the wetting properties in methanol under the above processing conditions is about 0.55. Wang ,Xun (Graduate of the department of chemical engineering) Directed by Prof. Guo,Renmin...