Abstract：After the brucite, raw material, was calcinated at 340 ℃in Muffle furnace, the magnesium hydroxide was obtained by hydrothermal reaction, sodium p-toluene sulfonate as inducer.The effect of sodium p-toluene sulfonate on the morphology of Mg(OH)2, and the cyclic performance of the inducer through the hydrothermal solution containing inducer recycle were studied.The results show that sodium p-toluene sulfonate play a similar crystal orientation agent role on the morphology of Mg(OH)_2.Sodium p-toluene sulfonate has good performance of usage repeatedly. By changing the hydrothermal solution of 5 mol/L sodium hydroxide solution, the surface polarity and the purity of magnesium hydroxide is improved.

Keywords: brucite; sodium p -toluene sulfonate; inducer; hydrothermal reaction; crystal orientation agent