What are the measures to extend the life of ladle refractory material in steel plant

In the normal production of steel, there are situations occur when the ladle gellan steel.Use good thermal conductivity refractory when lining-up may aggravate this phenomenon, combined with molten steel due to the temperature drop, which will create sticky residue lining the surface of serious problems within the ladle . Here Henan refractories plant was introduced to prolong the life of ladle  magnesia carbon brick  measures.

1.refractory brick for sale and masonry improve the way
In order to ensure that the masonry and flaking masonry lining less firmly connected properly changing the shape of the brick lining, made of shaped bricks to increase thermal stresses can be compensated by the number of vertical joints and bricks made of arc-shaped surface.Package wall spiral style method masonry, bricks can reduce consumption by more than 15%.
To prevent cracks between the blocks in LF ladle bottom lining erosion, Kobe Steel improved masonry structure. Concentric masonry package by the end of mullite corundum products, the central area (steel flow impact zone) with high alumina castable precast masonry block.This approach allows the masonry thinner than the central region surrounding the bottom half of the pack, lining life increased from 30 times 40 times, repair times reduced by two times 1 times.
Existing interface between the bricks can prevent crack propagation, interaction between the liner and the slag generated.Or between the safety liner and add a layer of tar dolomite working lining tar dolomite ramming material, or in use can be carbonized material.

2. Drying

(1) microwave heating
Microwave heating is a new thermal technology, compared with conventional heating, microwave heating without an external heat source, but the material is heated inside the microwave electromagnetic radiation, promote their movable particle motion, collide with each other so that friction heat. Monolithic refractory material for ladle body construction using microwave heating, which greatly speeds up the reaction process, since the temperature difference between the surface and the interior of the small settlement burst release and tissue degradation phenomenon, the entire liner can be quickly heated and uniformly dense tissue . Heating time (conventional heating formerly required 24h) reduced to 8h.

(2) Quick baking apparatus
Anyang Iron and Steel Company second steel mill 25t ladle quick energy-saving baking apparatus using oxygen combustion, so that combustion gas can improve the thermal efficiency of over 50%.The practical production shows that it has a short baking time, adaptable, bake evenly, easy to operate, safe and reliable.Ladle down time from the past 40h 16h.Not only solves the gas pressure is low due to the impact Ladle problems, and effectively improve the baking quality of the ladle, to avoid the containment wall bricks crack phenomenon in the past due to the uneven baking caused.

(3) baking coal oxygen apparatus
 Arm spin move or horizontal coal oxygen baking, preheat temperature in 1h refined package can reach 1000 - 1200 ℃.  Effectively prevent slag line MgO-C, due to acute heat stress caused by thermal quench. Electric furnace refining temperature and time were decreased and shortened. Improve productivity and ladle life, reduce production costs and coordinate production order also plays a significant role.

3. Maintenance repair
Uneven ladle refractory lining is damaged, it is necessary to take repair, gunning and other measures to shore up weak links, to improve job ladle refractory consumption rate decreased, making the fullest use of the lining, to achieve the purpose of the high life.

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Magnesia aluminum refractories is Basic Refractories

Ladle Magnesia Carbon Brick are used in Ladle linings, ladle upper and lower slag line, ladle wall and ladle bottom

Magnesia aluminum refractories of Basic Refractories:
Ladle steel industry is an important and indispensable equipment, as ladle lining, several major changes. Used to be traditional by sintering of clay refractory brick and third class alumina brick, the refractory material shows poor chipping resistance and corrosion resistance during use, low life, an average of only 10 times, dried treatment can only reach about 20 times. With the development of steelmaking technology, refining the molten steel to improve the outer retaining ladle lining insulating castable requirements in the early years of the 20th century that is, once the application as a whole

Cast Mg-Al quality ladle lining material. This lining integrity, and significantly improve the service life, but there are baked ladle long time, there are more serious dregs phenomenon for medium and small mills no special equipment most circumstances, unpacking difficult. To compensate for this deficiency, then the successful application of aluminum-magnesia unfired brick. The lining brick building is easy to assemble, baking time is short and easy unpacking, but still easy to kill slag and chipping resistance is poor. On this basis, in order to overcome the problem of aluminum-magnesia unfired brick ladle lining easy cat slag around the corner late he has not developed the aluminum-magnesia carbon brick, replacing the aluminum-magnesia unfired brick. The material combines the properties of aluminum-magnesia material and carbonaceous material. The main advantages of aluminum-magnesia carbon brick does not have: no cracks between the blocks melt loss, has good resistance to thermal shock resistance and slag ability to overcome the structural steel and slag penetration flaking, significantly improved service life and so on. Because the article is not burning or low-temperature firing, save energy, reduce costs, economic efficiency is very obvious, it attracted people's attention.


China advised in the 20th century, it began with bauxite and magnesite (or light burned MgO) magnesia aluminate spinel raw materials research. In recent years, also carried out a series of studies preparation of magnesia spinel products combine technology, achieved a lot, but the performance has been excellent in high purity products suffer from a high degree of firing is very limited. Domestic activity spinel powder was used. The ultra-high temperature firing process overseas (1 850c) down to 1 660C. But for the average coal-fired furnace refractory general terms, it is still difficult to achieve. To this end, the domestic refractory experts and scholars made active magnesia aluminum gum as a binding agent, was studied with the active Mg-Al gum as binding agent and high-purity magnesia carbon brick magnesia brick spinel combination of performance, the use of magnesia aluminum adhesive activity, both make excellent performance products fired at 1 550 ℃, such as the advanced products in firing ordinary refractory kiln plant in Shanghai possible.


Through active lime kiln back to actual production, research and development of magnesia aluminate spinel unfired brick. Use show, developed spinel unburned brick in the active lime kiln firing service life of more than one year. For a long time, directly from the dry combination of MGO brick manufacturers with excellent slag resistance and corrosion resistance, it is used in large alkaline rotary kiln Pu left. Currently the most widely used range of the steel industry, most of the largest refractory Mg - Al system is unshaped refractory, accounting for about 85% of the unshaped refractories of total production, it is widely used in the converter, ladle, iron package, furnace and blast, virtually all metallurgical thermal equipment.


Spinel has a high melting point, small thermal expansion, low thermal stress, thermal vibration stability, and it has a more stable chemical properties of alkaline slag has a strong resistance, aluminum-magnesia do not burn brick core point to be used, is one of the key substances to improve life. Due to the gradual maturity in recent years, synthetic spinel technology, the use of synthetic spinel materials directly produce good ladle brick as possible, so that it can significantly improve the properties.


Quality spinel is one of the key issues related to the inter-spinel bricks can achieve the proper effect. By introducing the screening laboratory tests and related information, the magnesia-rich spinel 20% to 30% of its corrosion resistance, structural spalling resistance and thermal shock properties are better. But ladle conditions are more factors in the production operation, the amount of added spinel requirements should be 30% to 40% is more reasonable. Therefore, in brick-making process, in addition to producing a good artificial spinel added, we must also note the addition of fused magnesia powder and alumina powder, so that the secondary spinel regenerated during use. Thereby improving bricks tomb of quality performance parts for the control of harmful impurities in particular low-melting material was Na20 and K2O content, the choice of raw materials need special attention exhausted.


Spinel (also known as spinel) has the formula MgO-Al2O3, containing Mg0 was 28.3%, Al2O3 71.7%. Spinel is only Mg0-Al2O3 binary system phase diagram of an intermediate compound, melting at 2 135 C.

Taphole Brick---Refractory Brick---Henan Xinmi Changxing Refractory Material Co., Ltd.

Taphole Brick---Refractory Brick---Henan Xinmi Changxing Refractory Material Co., Ltd.

Taphole brick is molded at isostatic pressure, with fused magnesia and graphite as raw material. It is characterized by good oxidation resistance, high strength, good corrosion resistance, good integrity, easy replacing and long life and it is ideal material taphole of large and medium furnace.

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The influences of raw material on magnesia carbon brick performance

 magnesia carbon brick refractory alkaline oxide is magnesium oxide (melting point 2800 ℃) and difficult to infiltrate a high melting point slag carbon material as a raw material, adding a variety of non-oxide additives. Made in conjunction with carbonaceous binding agent is not charcoal refractory composites. MgO-C is mainly used for the converter, AC arc furnace, DC arc furnace lining, ladle slag lines and other parts.

MgO-C brick composite as a refractory material, the effective use of high thermal conductivity and strong resistance to slag erosion ability of magnesia and carbon and low expansion, the biggest drawback is compensated magnesia poor chipping resistance.

Its main features are:
1, has good high temperature performance
2, strong resistance to slag
3, good thermal shock resistance
4, low temperature creep

MgO-C material impact on performance

The main raw material for the production of magnesia carbon bricks properties, magnesia quality will have a crucial impact on the performance of MgO-C, magnesia how reasonable choice is the key to the production of MgO-C. There magnesia and fused magnesia sinter magnesia, which have different characteristics. Fused magnesia: grains, less impurities, less silicate phase, a high degree of direct bonding grain, less grain boundaries.

Sintered magnesia: fine grain impurities silicate phase relative called more directly the degree of integration is poor.

For magnesia raw materials, in addition to the chemical composition, in terms of organizational structure, also called high density and large crystal, therefore, as magnesia magnesia carbon bricks manufacturers
 produced raw material quality indicators used, the following should be investigated:

1, magnesium oxide content (purity)
2, the type of impurity, particularly .C / S and B2O3 content
3, magnesia density, pore size, pore morphology (sinterability).

Purity magnesia has a major influence on slag resistance of MgO-C. Magnesium oxide content is higher, relatively fewer impurities and reduce the degree of segmentation silicate phase, periclase directly bonded to improve the degree of melting loss resistance to slag penetration and slag increased. Magnesia in the juice mainly calcium oxide, silica, iron oxide, if the impurity content is high, especially compounds of boron oxide, magnesia refractoriness and high temperature will adversely affect the performance.

Magnesia of impurities separated at mainly affect several aspects of a periclase reduce the degree of direct bonding at a high temperature of magnesium oxide 2 forming a low-melting material 3 iron, silica and other impurities in the 1500-1800 ℃, the first magnesium oxide react with carbon, leaving pores so that slag resistance of the article deteriorates.

For magnesia raw materials, in addition to the total amount of impurities, the type of impurity and magnesia performance relative content team also have a significant impact. Which affect the CaO / SiO2 ratio and B2O3 content in the most obvious, the general magnesia refractories usually require CaO / SiO2≥2 MgO-C in order to improve the high temperature stability
Preparation of MgO-C materials mainly carbon flake graphite.

Article Source:

http://yilongrefractory.blogspot.com/2016/09/the-influences-of-raw-material-on.html

Magnesia Carbon Brick

Magnesia carbon brick series used for the electric furnace are made by adoption of fused magnetite, high-purity magnesium sand and graphite as principal raw material, through high-pressure molding and low-temperature treatment. This product is mainly used for electric furnace lining, which enjoys advantages including high temperature resistance strength, corrosion and spalling resistance. According to the smelting conditions and the kind of smelting steel, different brands magnesia carbon bricks are available. Magnesia-carbon bricks are resin bonded bricks containing high-purity fused and or sintered magnesia and flake graphite as their main ingredients.


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