Depending on the enterprise, refractoriness magnesia may be brick, magnesite brick, or magnesite brick. However grey kiln enterprise USES high charge soft brick to be better than phosphate brick, but high charge soft brick is 2.8 above body density just is good. The reason is that the erosion of this kiln is very great, and phosphate brick has better wear resistance than high-load soft brick.
Magnesia brick sharp stone, with magnesia alumina sharp crystal is still some, but the amount of magnesia alumina sharp crystal aluminum can exceed, does not form spinel, easy to crack. Magnesia bricks are also useful, but their thermal shock stability is not as good as that of magnesia alumina spinel bricks. So, it is better to choose magnesia alumina spinel brick. Choose magnesia alumina spinel brick aluminum content cannot exceed for good, choose high charge soft brick body density to want to be in 2.8 above just go.