The magnesite calcined at 1550-1600℃ is called sintered magnesite. Using vertical kiln, rotary kiln and other high temperature equipment one calcination or two step calcination process, with natural magnesite as raw material to burn burnt magnesite is called sintered magnesite; According to its physical and chemical indexes, sintered magnesia can be divided into 18 grades. See GB/T 2273-1998 for details. With magnesite as raw materials by electric arc furnace melting to the molten state after cooling is called fused magnesite; The magnesia extracted from seawater is called Marine magnesia. High purity magnesia is made of natural super grade magnesite by flotation purification, light burning, fine grinding, ball pressing and calcination in ultra-high temperature oil vertical kiln. It is a high quality material for making bricks and refractory materials.
Medium-grade magnesia is made of light burned magnesium oxide with MgO content of 97% by the process of ball pressing and high temperature vertical kiln calcination. The product has good sintering degree and compact crystallization. It is a high quality raw material for producing middle-grade magnesia refractory products. It can also be used for manufacturing various magnesia bricks, magnesia aluminum bricks, ramming materials, filling furnace charges, etc.