Research of Synthesizing Magnesium Hydroxide with Magnesium Sulfate and NH_3

Magnesium hydroxide of high slurry content was directly synthesized using magnesium sulfate and ammonia as the raw materials. This study showed that optimal process parameters were stirring speed of 450 r / min,ammonia to magnesium ratio of 2. 4∶ 1,ammonia addition rate of 500 mL / min,aging time of 60 min,reaction temperature of 60 ℃ and magnesium sulfate concentration of 2. 50 mol / L. The products were characterized by scanning electron microscope,X-ray diffraction and laser particle size analyzer. The magnesium hydroxide was obtained by using the optimal reaction conditions with the D 50 of 12. 06 μm,the D90 of 18. 99 μm,and the purity of 96. 75%. The reaction yield reached 68. 02% with a magnesium hydroxide slurry content of 7. 37%.