Production method of electrical grade magnesium oxide powder

In order to improve the extraction rate of electrical grade magnesium oxide powder and reduce product energy consumption. To improve product quality and increase product variety, the double subtraction carbonization process mainly changes the carbonization conditions and reduces the production process with high energy consumption. The purified lime lotion is carbonized under specific conditions to dissolve 80-90% MgO and generate a supersaturated solution of light magnesium carbonate containing 20-30 g/L MgO. After rapid pressure filtration, the saturated solution of light magnesium carbonate is decomposed into basic magnesium carbonate at 20-30 ℃ under specific conditions. This basic magnesium carbonate filter cake contains only 50-60% water. The light magnesium oxide product is obtained by calcination.

The process features:

(1) The extraction rate of magnesium oxide increased by 20-30%.

(2) The compression and pyrolysis processes are subtracted, and the moisture content of the basic magnesium carbonate filter cake is reduced by 25-30%.

Therefore, the coal consumption per ton of light magnesium oxide products is reduced by 75%. Power consumption is reduced by 65%.

Gas phase method

The high-purity metal magnesium reacts with oxygen to form crystal nucleus, and then the particles continue to grow to prepare high-purity micro-powder magnesium oxide. The crude raw material containing more than 80% (weight) of magnesium oxide is dissolved with inorganic acids (sulfuric acid, hydrochloric acid, nitric acid) in a molar ratio of 1:2 to produce magnesium salts of inorganic acids. The impurities are refined and removed, and pressurized and heated in oxygen atmosphere, then washed, dehydrated, dried, and heated at 1100 ℃ for 1h to prepare high-purity magnesium oxide.

The magnesium hydroxide calcination method uses the purified magnesium sulfate solution as the raw material, and uses pure ammonia water as the precipitator to precipitate Mg (OH) 2 in the magnesium solution. After solid-liquid separation by plate and frame filter press, the filter cake is washed to obtain high-purity Mg (OH) 2, and then dried and calcined to obtain high-purity magnesium oxide.

The calcined bitter clay powder is washed and precipitated into magnesium slurry after removing impurities. Then the magnesium hydroxide is dehydrated to produce magnesium oxide through digestion, drying and calcination. Its MgO+H2O → Mg (OH) 2Mg (OH) 2 → MgO+H2O;