Microstructure of magnesia brick

The microstructure of magnesia bricks is actually a combination of magnesia microstructures. The microstructure of magnesia bricks produced with one raw material is the simplest. A magnesia brick made of British seawater magnesia with almost no silicate except for pores in the matrix. Intracrystalline and intercrystalline micropores of periclase are characteristic structural parameters. The production of magnesia bricks mainly relies on the sintering of the liquid phase in the magnesia fine powder matrix to achieve the combination between particles. Therefore, raw materials with high purity are difficult to sinter, and seawater magnesia bricks should be made at a temperature of 1700~1800 degree or even above 1850 degree . temperature fired. The bricks with more silicate (CMS) can be sintered at 1500~1600 degree . Therefore, common magnesia bricks are dense, while seawater magnesia bricks are porous. However, it shows the opposite results in terms of high-temperature mechanical properties. For example, the softening temperature of sea water magnesia bricks under load is higher than 1700 degree ; generally, sintered magnesia bricks are 1500~1600 degree . High-purity magnesia bricks produced abroad mostly use seawater magnesia or seawater magnesia combined with fused magnesia.