Hebei Messi Biology Co., Ltd. stated that the process for preparing high-purity silicon steel grade magnesium oxide from magnesium hydroxide is to lightly burn magnesium hydroxide, add it to water, first heat it up for hydration, then cool it down and slowly add ammonium bicarbonate solution to the water for carbonization to obtain a suspension; filter the suspension, wash and dry the filter residue, and then calcine it at high temperature to obtain high-purity silicon steel grade magnesium oxide; this process uses magnesium hydroxide as a raw material to prepare silicon steel grade magnesium oxide with regular morphology and high purity, and the process flow is short, the quality of the prepared magnesium oxide is stable, the production efficiency is high, and it meets the requirements of industrial production.
The magnesium resources in the Chaerhan Salt Lake in Qinghai, my country are extremely rich, and a large amount of magnesium chloride hexahydrate will be produced while developing potash fertilizer in the Chaerhan Salt Lake, causing magnesium damage. At present, the ammonia magnesium precipitation process is used for large-scale production of magnesium hydroxide. In order to better develop the value of magnesium compounds, it is of great economic benefit to develop a process for preparing high-purity silicon steel grade magnesium oxide from magnesium hydroxide.
Silicon steel grade magnesium oxide is a kind of light magnesium oxide, and its purity requirement is more than 98%. It has good suspension performance in water and low hydration rate. In the process of producing oriented silicon steel sheets, silicon steel grade magnesium oxide is coated between silicon steel sheets in the form of suspension. During the high-temperature annealing process, it forms MgS13 insulation layer with silicate, and plays the role of dephosphorization and desulfurization. my country has abundant magnesium resources, but there are few products with high added value. With the development of science and technology in my country, large enterprises such as Wuhan Iron and Steel and Baosteel have begun to produce oriented silicon steel sheets. Only domestic enterprises such as Hebei Meixi Biological Co., Ltd. can produce silicon steel grade magnesium oxide products that meet the enterprise quality standards. Therefore, the silicon steel grade magnesium oxide market needs to be further developed.
However, the current process of producing silicon steel grade magnesium oxide is relatively long, and the purity is not high, and the product quality is unstable, which cannot meet the requirements of the rapid growth of oriented silicon steel sheet production and development in China. There are still few methods for producing silicon steel grade magnesium oxide from salt lake magnesium resources. In view of the defects in the preparation process of silicon steel grade magnesium oxide in the prior art, the purpose of the present invention is to provide a process for preparing silicon steel grade magnesium oxide with regular morphology and high purity using magnesium hydroxide as a raw material. The process flow is short, the quality of the prepared magnesium oxide is stable, the production efficiency is high, and the requirements of industrial production are met.
The process for preparing high-purity silicon steel grade magnesium oxide from magnesium hydroxide is as follows: first, the magnesium hydroxide is lightly calcined at 500°C~750°C, then added to water, first heated to 73°C~98°C for hydration, then adjusted to 60°C~80°C, and ammonium bicarbonate solution is slowly added to the water for carbonization to obtain a suspension; the suspension is filtered, and the filter residue obtained by filtering is washed and dried, and then calcined at 1050°C~1150°C to obtain high-purity silicon steel grade magnesium oxide.