SYNTHESIS OF HIGH PURITY AND NANOMETER MAGNESIUM OXIDE FROM LIGHT CALCINED MAGNESITE

High pure magnesium sulfate solution was obtained by light calcined magnesite as raw materials after purification.Nanometer magnesium oxide powder was synthesised by direct precipitation method using oxalic acid as precipitator.The effects of various factors such as the mole ratio of oxalic acid to magnesium oxide,reaction temperature,thermal decomposition temperature and time of magnesium oxalate precursor on the particle size of nanometer MgO was investigated systematically.The thermal decomposition process of the precursor was investigated by thermaogravimetric-differential thermal analysis.The particle size measurement,X-ray diffractometer,scanning electron microscope were used to characterize the structure and size of MgO particle.The results indicate that the product is well dispersed with narrow particle size distribution and an average-size of about 80 nm.Purity of magnesium oxide in products is over 99.1%.