Silicon steel magnesium oxide is named after the industrial use of magnesium oxide. It is mainly used as an isolation agent, dephosphorization, and desulfurization agent during high-temperature annealing during the preparation of oriented silicon steel sheets. It will form MgSiO3 on the surface of silicon steel with SiO2, and further react to form an insulating Mg2SiO4 coating. Due to its special use, silicon steel grade magnesium oxide has the following requirements: high purity, low hydration rate, good water suspension, appropriate activity and strong adhesion. The main methods for producing silicon steel grade magnesia include brine ammonium bicarbonate method and dolomite carbonization method.
Magnesium oxide for silicon steel coating is an important insulating material used in the production of oriented silicon steel. Grain-oriented silicon steel has excellent magnetic properties and is widely used in power transformers and other electromagnetic devices. The magnesium oxide coating can prevent the grain growth of oriented silicon steel and improve the magnetic induction intensity and magnetic loss coefficient of oriented silicon steel.
In recent years, with the development of grain-oriented silicon steel production technology, higher requirements have been placed on magnesium oxide for silicon steel coating. Researchers continue to develop new magnesium oxide preparation methods and coating processes to improve the performance of magnesium oxide coatings.
Preparation method of magnesium oxide
The preparation methods of magnesium oxide for silicon steel coating mainly include the following:
Ammonium carbonate method: Mix magnesium oxide solution and ammonium carbonate solution, and control the pH value and temperature to uniformly precipitate magnesium oxide. The magnesium oxide produced by this method has high purity and fine particle size, but the production cost is high.
Carbonization method: Pour in magnesium oxide solution and carbon dioxide to precipitate magnesium oxide. The magnesium oxide produced by this method has coarse particle size, but the production cost is low.
Hydration method: It is obtained by calcining and pulverizing magnesium oxide and then hydrating it. The magnesium oxide produced by this method has high activity, but is easily hydrated.
Ammonia method: Mix magnesium oxide solution and ammonia water, and precipitate magnesium oxide by controlling the pH value and temperature. The magnesium oxide produced by this method has high purity and fine particle size, but the production process is complicated.
Magnesium oxide coating process
The coating process of magnesium oxide for silicon steel coating mainly includes the following:
Solvent coating method: Disperse magnesium oxide powder in a solvent to make a coating, and then apply the coating to the silicon steel surface using a coating method. This method has a simple process, but the volatilization of the solvent will cause environmental pollution.
Water-based coating method: Disperse magnesium oxide powder in water to make a coating, and then apply the coating to the silicon steel surface using a coating method. This method is environmentally friendly, but the coating has poor water resistance.
Electrophoretic coating method: Magnesium oxide powder is dispersed in the electrolyte, and under the action of the electric field, the magnesium oxide particles are deposited on the surface of the silicon steel. This method has a uniform and dense coating, but the process is complicated.
Research progress
In recent years, researchers have conducted a lot of research on the preparation methods and coating processes of magnesium oxide for silicon steel coatings, and have made the following progress:
A method for preparing high-purity, fine-grained magnesium oxide was developed to improve the performance of magnesium oxide coatings.
An environmentally friendly and energy-saving magnesium oxide coating process was developed to reduce production costs.
The modification method of magnesium oxide coating was studied to improve the wear resistance, high temperature resistance and corrosion resistance of the coating.
future outlook
With the development of grain-oriented silicon steel production technology, the demand for magnesium oxide for silicon steel coating will further increase. In the future, research on magnesium oxide for magnesium oxide coatings will develop in the following directions:
Develop a more efficient and environmentally friendly method for preparing magnesium oxide.
Develop a more uniform and dense magnesium oxide coating process.
Research new magnesium oxide coating materials to improve the performance of the coating.
With the rapid development of the economy, new requirements have been put forward for the output and quality of silicon steel. Silicon steel grade magnesium oxide, as an important silicon steel coating material, has also developed from the initial generation product to the current third generation product and even to the fourth generation product under development. At present, the domestic production of grain-oriented electrical steel is about 1.34 million tons per year, and the demand for silicon steel grade magnesium oxide is between 8,000 and 11,000 tons. However, my country’s silicon steel grade magnesia production capacity is low, the product gap is large, and CNC and equipment automation technology is backward. These The problems need to be solved urgently.