Under laboratory conditions,a refined salt solution was prepared by reacting lightly burned powder with ammonium salt.A certain flow rate of ammonia gas was introduced into the magnesium salt solution at a certain temperature and stirring rate.

High quality flame retardant magnesium hydroxide was prepared by direct precipitation method.The effects of reaction temperature,ammonia flux,magnesium settling time and stirring rate on the particle size morphology of magnesium hydroxide were studied.The morphology and partide size and shape of the product were characterized by techniques such as vacuum scanning electron microscope(SEM) and laser particle size distributor.The experimental results showed that the magnesium precipitation reaction was based on 250 mL system.When the reaction temperature was 60 ℃,the ammonia penetration rate was 200 mL/min,and the stirring speed was 250 r/min,flake magnesium hydroxide with consistent morphology and good dispersion could be prepared at 2 h.