Salt Lake Brine Preparation Of Silicon Steel Grade Magnesium Oxide

Silicon-steel Magnesium oxide Silicon-steel Magnesium oxide is used as the isolating agent in the process of silicon steel sheet's high temperature annealing, This paper studied the preparation of silicon-steel grade magnesium oxide from saline brine. This method has simpler process, lower costs and higher product purity compared with other methods, and the purity can reach more than 99%.We determined the atmospheric ammonia process method by comparing with other various methods of the preparation of magnesium hydroxide. Though studying the affecting factors in this process, we determined the best conditions of the experiment in which the concentration of magnesium ion is 4.3mol/L, the concentration of ammonia is 28%, the reaction temperature is 90℃, the joining velocity of saline bischofite is 3.3 mL/minute, the pH of react liquid is about 9.The sample of magnesium hydroxide prepared under these conditions has good filtration performance, high conversation rate , conversation rate is about 95%, and it has hexagonal crystalline system, and has the shape of platelet, the purity of the sample is ninety-nine point six percent and the average size of the particle is about 22.643μm.The crushed magnesium hydroxide was prepared to be calcined to made for Magnesium oxide. By studying the calcining temperature and the calcining time we determined with the temperature increasing and the time longing the hydration rate decrease, and the hydration rate can reduced more when cooled under vacuum state. So, the best calcining temperature is about 1200℃, the calcining time is for 3h, the hydration rate of the magnesium hydroxide sample is 3.47%, and it's hydration rate can reduced to 3.20% when cooled under vacuum state .The calcined Magnesium oxide samples were analysised by XRD, and laser particle size analysis Instrument. Samples almost don't have impurity, the purity is ninety-nine point six percent. Samples have crystal structure and uniform particle size and well-dispered. The average size of the particle is 2.635μm,the particle that smaller than 5μm is 82.8%. All indexes are superior to the indexes that required.