Magnesia dolomite brick is also called high calcium magnesium brick. Magnesia refractories with cristobalite as the main crystalline phase and tricalcium silicate as the secondary crystalline phase. Contains MgO 80% ~ 87%, CaO 6% ~ 9%, CaO/SiO2 ratio between 2.2 ~ 3.0. The obvious structural feature is that the periclase is in direct contact with dicalcium silicate and tricalcium silicate, and the eutectic (4CaOAl2O3Fe2O3) fills the crystal gap of dicalcium silicate and tricalcium silicate in fine veins. The porosity is low. The starting temperature of softening under load is generally higher t
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Magnesia Dolomite Brick Details
Magnesia dolomite brick is also called high calcium magnesium brick. Magnesia refractories with cristobalite as the main crystalline phase and tricalcium silicate as the secondary crystalline phase.
Contains MgO 80% ~ 87%, CaO 6% ~ 9%, CaO/SiO2 ratio between 2.2 ~ 3.0. The obvious structural feature is that the periclase is in direct contact with dicalcium silicate and tricalcium silicate, and the eutectic (4CaO·Al2O3·Fe2O3) fills the crystal gap of dicalcium silicate and tricalcium silicate in fine veins. The porosity is low. The starting temperature of softening under load is generally higher than 1700 ℃, and the alkali slag resistance is good. However, the thermal shock resistance is poor. The calcium magnesium sand is used as the raw material, after crushing, batching, mixing, and molding, the It is fired at a high temperature of 1550~1600℃.
It is used in the air eye of the steel-making side-blown converter, open hearth furnace top, oxygen-blown converter upper and other places.
Magnesia dolomite brick is a magnesia compound refractory material with MgO and CaO as the main chemical components. Its main mineral composition is cristobalite and cristobalite, both of which are high-melting minerals, which do not react at high temperature to generate new The compound minerals exist in an independent form and maintain their own inherent characteristics.
Cristobalite has good high temperature plasticity, which can buffer the thermal stress generated inside the brick due to temperature changes; cristobalite reacts with SiO2 in the slag to generate high melting point minerals C2S and C3S, which improves the viscosity of the slag and reduces it. The penetration of the slag into the brick improves the anti-stripping performance of the brick; calcite can absorb non-metallic inclusions such as S, P and AI2O3 in molten steel.
Therefore, the magnesia dolomite brick has good thermal shock stability, good structural spalling resistance and slag penetration resistance, and also has the unique performance of purifying molten steel.
Features
Good thermal shock resistance performance
Excellent resistance in slag abrasion
Good cold crush strength
Higher temperate resistant with good refractoriness
low creep and better flaking resistant.Good
Applications
Mainly used for steel refining furnaces like AOD,VOD furnace
Specifications
Mgo and CaO content
Widely used throughout steel refining furnaces like AOD,VOD furnace
Physical And Chemical Indicators
Brand |
MD15 |
MD20 |
MD25 |
MD30 |
MD40 |
|
Bulk Density (g/cm3) |
3.03 |
3.03 |
3.03 |
3.03 |
3 |
|
Apparent Porosity (%) |
13 |
12 |
12 |
13 |
13 |
|
Cold Crushing Strength (MPa) |
80 |
90 |
80 |
80 |
80 |
|
Permanent Linear Change (%)@ 1,500℃ x 2hrs |
-- |
-0.35 |
-- |
-0.61 |
-- |
|
Refractoriness Under Load (℃) @0.2MPa |
1700 |
1700 |
1700 |
1700 |
1700 |
|
Chemical Composition (%) |
MgO |
80.3 |
76.3 |
70.3 |
66.3 |
56.3 |
CaO |
17 |
21 |
27 |
31 |
41 |
|
Al2O3 |
0.5 |
0.5 |
0.5 |
0.5 |
0.5 |
|
Fe2O3 |
0.7 |
0.7 |
0.7 |
0.7 |
0.7 |
|
SiO2 |
1.3 |
1.3 |
1.3 |
1.3 |
1.2 |
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Products Desc
Products Description The main components of alkali resistant bricks are clay, high alumina, quartz sand, bauxite and other alkali resistant materials, among which quartz sand and bauxite can improve alkali resistance, clay and high alumina can increase sintering pressure, so that alkali-resistant bri...
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