Magnesite series, which belongs to alkaline refractory materials, is made of magnesite grit and owns a quite high content of magnesium oxide. The series can be usually divided into two types: sintered magnesite product and chemical bonded magnesite product (or non-sintered magnesia product). Due to direct contact of periclase crystal grain, the magnesia product with high purity and sintered temperature is called direct-bond magnesite brick; The product made of fused cast magnesite grit is called rebonded electrically fused magnesite brick.
Sintered magnesia series made of magnesia bricks is produced by the process of grinding, batching, mixing, moulding and sintering with high temperature of 1550~1600ºC. And the temperature of sintering to high purity product should be more than 1750ºC. Moreover, sintered-free magnesia product, with adding chemical binder into magnesite grit, is produced by mixing, moulding and drying.
With basal component of magnesite grit, magnesia-chrome product, magnesia-zirconium product and magnesia-carbon product are supposed to be obtained respectively by adding a certain amount of chromium, zirconium and carbon components. In addition, it brings a better improvement on resistance of erosion and stripping among these products.
It is mainly used in regenerator of glass furnace and top space of parts of glass furnace, and can be also used in metallurgy field.
Magnesia series has strong alkalinity, high density, high refractoriness, excellent alkali slag resistance, high refractoriness under load, but poor resistance of thermal shock.
Physical and Chemical Indicators
High-grade Magnesia Brick (A2101)
The brick is made from top and high perity magnesia sand by highly pressing and firing at high temperature, which has an excellent resistance of alkali.
Magnesia-zirconia Brick (A2102)
The brick is made from high-grade magnesia sand, fine zircon and high-grade synthesized magnesia-zircona by highly pressing and firing at high temperature, which has a uniformity on structure under preparing of direct bonded Periclase-calcium zirconate. resisting to the corrosion from melt slag and liquid. A better high strength and thermal shock resistance.
Direct Bonded Magnesite Chrome Brick (A2103)
The brick is made from high purity magnesia sand, fine chromite ore and additives by highly pressing and firing at high temperature. Resisting to spall at high temperature.
Resintered Brick of Fused Magnesia (A2104)
The brick is made of high-grade fused magnesia sand by highly pressing and firing under superhigh temperature, which has the densified structure to resist to penetration and corrosion at high temperature, suitable to use in regenerator in glass tank.