Messi Biology has demonstrated a preparation method for silicon steel grade magnesium oxide coating specially used for oriented silicon steel sheets, including the following process steps: select natural cryptocrystalline magnesium guaminite to produce light flammable magnesium oxide powder; digest light flammable magnesium oxide, neutralize and decalcify, react at a temperature of 15-30℃ and a time of 5-15 minutes to produce magnesium hydroxide, and then calcined at a temperature of 1100±50℃ and a time of 2.0±0.5 hours to obtain high-purity magnesium oxide; it is processed by airflow grinding to the required micron-scale particle size section.
In order to improve the reaction capacity between magnesium oxide and silica, magnesium oxide must be active, and nanomagnesium oxide has the greatest reactivity. Therefore, the introduction of nanomagnesium oxide particles in magnesium oxide for silicon steel coatings using nanotechnology has improved the reactivity of magnesium oxide in silicon steel. In order to improve the stacking density between magnesium oxide particles on the surface of silicon steel sheets, the substructure of magnesium oxide material for silicon steel coating must tend to be approximately spherical because the sphere has the advantage of closest packing, and magnesium oxide particles can tend to be tightest packing after being coated on the surface of silicon steel sheets.
Since magnesium oxide acts on the silicon steel sheet, it must be dried and curled into a coil for secondary high-temperature annealing. Before entering the high-temperature annealing stage, the water molecules in the magnesium hydroxide generated by magnesium oxide during the beaten process must be gradually driven away during the annealing and heating process. During this process, the coated magnesium oxide layer must be required to have good breathability, even if the water molecules in magnesium oxide can escape from the tightened steel coil gaps to avoid water vapor affecting the quality of the orthosilicate film generated. Therefore, as magnesium oxide for high-temperature annealing, a single nanomagnesium oxide material cannot be used, but the magnesium oxide should be a collection of magnesium oxides of various different particle sizes, that is, magnesium oxide materials of various different particle sizes should each occupy a certain distribution ratio.
Magnesium oxide for silicon steel coating produced by Messi Biology has the characteristics of high chemical purity, low impurity ions, good suspension, low hydration rate, good coating and adhesion. Its physical properties are far superior to similar products and are a good annealing isolator for the production of oriented silicon steel sheets; and the production process is simple and greatly reduces production costs.