Surface Modification and Preparation of High Purity Nanometer Magnesium Hydroxide Using Impinging Stream

摘要

High purity nanometer magnesium hydroxide is produced by impinging stream reaction crystallization method using bischofite as feedstock. Effects of operation conditions on the impinging stream of Mg (OH)_2 are reported and the control factors of purity are confirmed. The morphology of the powder was characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). Result shows that purity of Mg (OH)_2 can reach 99% and the mean size of crystal is 13.5nm. Surface modification of nano-sized magnesium hydroxide using four surface modifiers such as sodium steatite, sodium laurylsulfonate, sodium oleate and sodium silicate were investigated in this paper. The modified magnesium hydroxide has smaller particle size, larger powder contact angle, slower sedimentation velocity, the less in-oil capacity than unmodified sample