Method for preparing special magnesium borate for oriented silicon steel

The invention relates to the field of oriented silicon steel plate manufacture, in particular to a method for preparing special magnesium borate for oriented silicon steel. The method solves the problems of poor adhesion, dispersibility and electromagnetic performance and the like of the conventional boron aid. The method comprises the following steps of: (1) pouring aqueous solution of magnesium bicarbonate and boric acid in a ratio into a reaction kettle; (2) performing sedimentation treatment on the mixed solution; (3) then conveying the sediment into a pyrolysis tank, adding finished magnesium borate crystal seeds and silane coupling agent into the pyrolysis tank, and producing a mixture of nano magnesium carbonate and metaboric acid by using a liquid phase precipitation method; (4) filter-pressing the pyrolysis product to obtain filter cakes; (5) treating the filter cakes in a high-temperature crystal oven to form nano magnesium borate powder with complete crystal; and (6) grading the material discharged