Magnesia Brick for Arc Furnace Introduction
Magnesium brick for Arc furnace is an alkaline refractory material with a magnesia content of more than 90% and a periclsite as the main phase. Magnesia refractory bricks for Arc furnace have high refractoriness, good resistance to alkaline slag, high starting temperature of load softening, magnesia firebricks have poor thermal shock resistance. Magnesia refractory bricks with high purity and high firing temperature are called direct bonded magnesia bricks because of the direct contact of the magnesite grains. Magnesia firebricks made of fused magnesia are called electrofusion and recombined magnesia bricks. Magnesiafire bricks mainly used in alkaline open hearth furnace, electric furnace bottom and furnace wall, permanent lining of oxygen converter, non-ferrous metal smelting furnace, high temperature tunnel kiln, calcined magnesia fire brick and cement rotary kiln lining, heating furnace bottom and furnace wall, glass kiln regenerator lattice brick.
Magnesia Brick for Arc Furnace Classification
The chemically bonded magnesia brick is not subjected to the calcination process. After the sintered magnesia is proportioned according to the particle size ratio, an appropriate amount of mineralizer and binder are added, the mixture is pressed and formed, after drying, magnesia refractory brick is a finished product. Magnesia refractory bricks are divided into sintered magnesium bricks and chemically combined magnesium fire bricks according to their different production processes. The sintered magnesia brick is made of calcined magnesia with appropriate particle size ratio, added with brine (MgCl2 aqueous solution) and sulfite pulp waste liquid as a binder, Magnesia bricks are formed by pressure molding at a high temperature of 1550~1650 °C. The chemically bonded magnesia refractory bricks have lower strength and lower performance than sintered magnesia bricks, but they are cheaper than half the price of sintered magnesia bricks. Magnesia refractory brick is used in areas where performance requirements are not too high, such as furnaces and soaking furnace bottoms.
Magnesia Brick for Arc Furnace Advantages
1.Magnesia fire bricks have good slag resistance.
2.Refractory magnesia bricks have stable at high temperatures.
3.Magnesia refractory bricks have good resistance to alkaline slag.
4.Magnesia refractory bricks have high temperature mechanical strength.
5.Refractory magnesia refractory bricks have strong resistance to erosion.
6.Fire magnesia bricks for Arc Furnace have load softening start temperature is high.
Magnesia Brick for Arc Furnace Selection Precautions
1.Magnesia refractory bricks have thermal stability is also poor
Magnesia brick is an alkaline refractory material, mgnesia refractory brick has strong resistance to alkaline slag, but can not resist the erosion of acid slag. At 1600 °C, mgnesia refractory bricks can be contacted with silica brick, clay brick or even high alumina brick.The refractoriness of magnesia fire bricks is above 2000 °C, but Magnesia fire bricks load softening point is only 1500~1550 °C. Moreover, the temperature interval from softening to 40% deformation is very small, and the thermal stability of only 30~50 °C magnesia bricks is also poor, Magnesia bricks is an important reason for the damage of magnesia bricks.
2. Magnesia refractory bricks have poor hydration resistance, easy to hydrate with water, and produce cracks and reduce their strength.
Magnesia Brick for Arc Furnace Specification
Item |
|
RS-97A |
RS-97B |
RS-95A |
RS-95B |
RS-93 |
RS-91 |
RS-89 |
RS-87 |
Mg |
% ≥ |
97 |
96.5 |
95 |
94.5 |
93 |
91 |
89 |
87 |
SIO2 |
% ≤
|
1.0 |
2.0 |
2.0 |
3.5 |
- |
- |
- |
- |
Cao |
% ≤
|
- |
- |
2.0 |
2.0 |
2.0 |
3.0 |
3.0 |
3.0 |
Apparent
Porosity |
% ≤
|
16 |
18 |
16 |
18 |
18 |
18 |
20 |
20 |
Cold Crushing Strength |
Mpa ≥ |
60 |
60 |
60 |
60 |
60 |
60 |
50 |
50 |
0.2MpaRefractoriness under load
|
℃ ≥ |
1700 |
1700 |
1650 |
1650 |
1620 |
1560 |
1550 |
1540 |
Magnesia Brick Physical and Chemical Properties
The refractoriness of magnesia refractory bricks can reach above 2000 °C, the load softening temperature varies greatly depending on the melting point of the cement phase and the amount of liquid phase produced at high temperatures. Generally, the load-softening start temperature of fire magnesia bricks is between 1520 and 1600 °C, while that of high-purity magnesia bricks is up to 1800 °C. The loading softening start temperature of the refractory magnesia brick is not much different from the collapse temperature. The linear expansion rate of magnesia bricks at 20~1000 °C is generally 1.2%~1.4%, mgnesia bricks refractory is approximately linear. When a liquid phase appears in magnesia brick at a high temperature, shrinkage suddenly occurs. Magnesia bricks have a higher thermal conductivity, mgnesia refractory bricks is second only to carbon bricks and silicon carbide bricks in refractory products, which decreases with increasing temperature. The thermal shock resistance of magnesia bricks is poor, the purity of magnesia bricks can be improved to improve the thermal shock resistance. Magnesia bricks have poor resistance to acid slag and cannot be directly contacted with silica bricks when used. Generally, they are separated by neutral bricks. Magnesium bricks have low electrical conductivity at normal temperature, but refractroy bricks cannot be ignored at high temperatures (such as 1500 ° C). If used in electric furnace bottoms, attention should be paid.
Magnesia Brick for Arc Furnace Production Process
The magnesia raw refractory material is crushed into granules and powders, after being compounded according to a certain ratio, the binder is mixed and formed into a mud material, then formed into a magnesia brick by molding, drying, firing, and the like. The firing temperature of ordinary magnesia bricks is generally 1500~1650°C, the firing temperature of high purity magnesia bricks is as high as 1700~1900°C. The chemical bonding magnesium brick production process is basically the same, but the chemical bonding agent is combined without high temperature firing, the low-temperature heat treatment is required to make the non-burned magnesium brick. Refer to the technical specifications provided by the RongSheng refractory factory.
Magnesia Bricks for Arc Furnace Supplier in RS Refractory Factory
1.Rongsheng refractory castable have rich refractory raw materials and 20 years experienced in the refractory bricks manufacturing. Rongsheng refractory castable can provide specification and category as well as competitive price & high grade quality refractory castable products.
2.Companies adhering to the "integrity, modesty, innovation, hard work" corporate philosophy, people-oriented business development is the cornerstone, the pursuit of excellence is the company's core values, the company's strategic goal is to create Rongsheng brand.
3.Rongsheng refractory brick is constantly committed to quality management, process management and cost management, strives for internal strength, adheres to the development of science and technology, wins by quality and reputation, provides technical guidance services to provide customers with quality products and services.