Low-grade magnesite calcination decalcification and silicon removal method for preparing high-purity light-burned magnesia

The invention relates to a low-grade magnesite calcination decalcification and silicon removal method for preparing high-purity light-burned magnesia, and belongs to the field of mineral resources processing. The method comprises the following steps: cleaning and crushing the low-grade magnesite containing dolomite and quartz, calcining magnesite powder with the particle size of 2.5 to 20 mm at 600-700 DEG C for 1 to 2.5 h to obtain a mixture of the decomposed magnesite, dolomite and quartz, and then performing selective milling to obtain a milling product; screening for classification to obtain a 0.074mm grain-level milling product; placing the magnesite powder with the grain level of 0.1 to 2.5mm in a suspension furnace for blowing and calcination, and calcining at 570 to 670 DEG C for 0.5 to 2 h to obtain the calcined magnesium recovered by suspension calcination; performing air separation and purification o the milling product and the light-burned magnesium subjected to suspensioncalcination, and finally