Magnesia refractory products overview
Magnesia refractory products mainly include ordinary magnesia bricks, magnesia silica bricks, magnesia calcium bricks, magnesia aluminum bricks and magnesia chrome bricks.
Magnesia refractories refer to refractories with magnesite as raw material, periclase as main crystal phase, and more than 80% – 85% MgO content.
Compared with other refractories, the refractoriness of magnesia refractories is up to 2000 ℃ It has a high load softening temperature, generally up to 1500-1650 ℃, but its thermal shock stability is poor. Magnesia refractories are divided into metallurgical magnesia and magnesia refractories.
The thermal conductivity of magnesia refractories is high and decreases with the increase of temperature; The thermal expansion coefficient is large, but the expansion process is relatively gentle; It has strong resistance to chemical attack of alkaline slag containing magnesium oxide and calcium oxide.
Ordinary Magnesia Bricks
The most important product of alkaline refractory, with high refractoriness, has good corrosion resistance to iron oxide, alkaline slag and high calcium solvent. There are fired magnesia bricks and unburned magnesia bricks. The firing temperature of fired magnesia bricks is generally 1550-1600 ℃, and the firing temperature of high-purity products is 1750 ℃, or even higher. The unburned magnesia brick is basically the same as the fired magnesia brick except that it does not go through the firing process.
Magnesia Silica Bricks
It is mainly composed of periclase and bound with forsterite as matrix Its performance is roughly the same as that of ordinary magnesia bricks. But its load softening temperature is higher than that of magnesia brick, and its slag resistance is also better.
Magnesia Aluminum Bricks
Magnesia alumina bricks are fired at 1580 ℃ using calcined magnesia with less calcium as raw material, adding about 8% industrial alumina powder and using sulfite pulp waste liquid as binder.
Compared with ordinary magnesia alumina bricks, magnesia alumina bricks have good resistance to rapid freezing and heat, and can withstand water cooling for 20-25 times or more, which is the outstanding advantage of magnesia alumina bricks.
Magnesia Silica Bricks
It is mainly composed of magnesite, with tricalcium silicate and dicalcium silicate as the combination. In addition to poor thermal shock stability, other performance indicators are superior to magnesia bricks.
Magnesia Carbon Bricks
It is made of high-quality sintered magnesia and carbon materials by pressing various carbon binders. It has a series of excellent properties such as corrosion resistance and peeling resistance.