How to make magnesia carbon brick

 The article describes in detail the process of how to make magnesium carbon bricks. What’s more, the article also expresses some other issues related to magnesia carbon bricks. Weclcome to visit our factory to see magnesium carbon brick product process.

Magnesia carbon brick Production process

The steps in the production process of MgO-C bricks are described here. First, the refractory raw materials are graded into coarse, medium, and fine sizes and are classified as necessary.  Next, they are mixed and kneaded with a binder in pre-determined blend proportions by parti­cle size. The kneaded mixture is press formed into bricks. 

By a magnesia-carbon brick there is understood a brick based mainly on the components burned magnesite, carbon in the amount of typically 5-30% carbon by weight and a suitable binder. Magnesia-carbon bricks are used in the wear lining of a converter for steel production, and are substantially more resistant to wear than magnesite bricks in which the percentage of carbon used is not so high. The wear lining of a converter can, depending on the price of the bricks, be wholly or partly constructed from magnesia-carbon bricks, especially at the location of the trunnions of the converter, where the wear is greatest.

Magnesia Carbon Brick for sale

Production process for MgO-C bricks

Uniaxial forming with an oil press or a friction press is normally used as the pressing equipment. The magnesia aggregate and graphite in MgO-C bricks show orientability depending on the forming di­rection of the press. The strength and thermal conductivity of MgO-C bricks show anisotropy . It is hence important to consider the forming direction of bricks when laying the bricks. A cold isostatic press (CIP) with small anisotropy is also used for the production of large refractory products such as bottom blowing tuyere bricks and taphole bricks.

Formed bricks are dried to remove moisture and other volatile components, processed, and coated as needed, visually inspected for cracks, chips, and other defects, and dispatched after removing defective bricks.

MgO-C (magnesia-carbon) refractories are widely used in several steelmaking linings. These refractories are exposed to extreme stress due to high temperatures (T > 1600 °C) required to cause the metallurgical reactions. These working conditions produced refractory wear through various related processes. The different types of degradation that the material suffers can be from thermochemical or thermomechanical origin.

Method for the manufacture of a magnesia-carbon brick, comprising the steps of:

a. preparing a mixture comprising:

1. burned magnesite

2. carbon

3. a binder solution comprising:

3.1 pre-condensed novolak resin

3.2 a solvent for this novolak resin.

4. a hardener for the resin.

b. pressing a brick from the mixture.

The method also provides bricks produced by the method and a converter having a wear lining consisting at least partly of such bricks.

FAQ:

How are magnesia carbon bricks made?

The traditional magnesia carbon brick manufactured by the synthetic tar binder in the cold mixing process is hardened during the process of tar damage and the necessary strength is obtained, thus forming isotropic glassy carbon.

What is the use of magnesia carbon bricks?

MgO-C (magnesia-carbon) refractory bricks are widely used in steel industry, the primary consumer of refractory linings, such as basic oxygen furnaces, electric arc furnaces, and ladle furnaces.

What is the raw material for magnesia carbon bricks?

Sea water magnesia is mainly used in SAIL as the main raw material for manufacturing of magnesia carbon bricks.

What is magnesia carbon brick?

Magnesia-Carbon brick is resin-bonded brick made from dead-burned or fused magnesia and graphite. Anti-oxidant is added if required. Our control over bonding agents mean that these products are classed as eco friendly in terms of steel production.

In conclusion, Welcome to learn how to make magnesia carbon bricks and learn other information about magnesia carbon bricks. If you are interested in other refractory products and production processes, please feel free to browse our website or visit our factory.

Article Source:How to make magnesia carbon brick
Company name: Henan Changxing Refractory Materials Co.,Ltd
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Magnesia Carbon Bricks

Brief introduction of raw materials for production of magnesia carbon bricks

 The main raw materials of magnesia-carbon bricks include fused magnesia or sintered magnesia, flake graphite, organic binders and antioxidants.

Magnesia

Magnesia is the main raw material for the production of MgO-C bricks, which can be divided into fused magnesia and sintered magnesia. Compared with sintered magnesia, fused magnesia has the advantages of coarse periclase crystal grains and large particle bulk density, and is the main raw material used in the production of ladle magnesia carbon bricks. The production of ordinary magnesia refractory materials mainly requires high temperature strength and corrosion resistance for magnesia raw materials. Therefore, attention is paid to the purity of magnesia and the C/S ratio and B2O3 content in the chemical composition. With the development of the metallurgical industry, the smelting conditions are becoming more and more severe. The magnesia used in the MgO-C bricks used in metallurgical equipment (converter, electric furnace, ladle, etc.) Large crystal.

Carbon Source

Whether in traditional MgO-C bricks or in widely used low-carbon MgO-C bricks, flake graphite is mainly used as its carbon source. Graphite, as the main raw material for the production of MgO-C bricks, mainly benefits from its excellent physical properties: ① Non-wetting to slag. ②High thermal conductivity. ③ Low thermal expansion. In addition, graphite and refractory do not eutectic at high temperature, and the refractoriness is high. The purity of graphite has a great influence on the performance of MgO-C bricks. Generally, graphite with a carbon content greater than 95%, preferably greater than 98%, should be used.

In addition to graphite, carbon black is also commonly used in the production of magnesia carbon bricks. Carbon black is a highly dispersed black powdery carbonaceous material obtained by thermal decomposition or incomplete combustion of hydrocarbon hydrocarbons. 99%, high purity, high powder resistivity, high thermal stability, low thermal conductivity, is a difficult graphitization carbon. The addition of carbon black can effectively improve the spalling resistance of MgO-C bricks, increase the amount of residual carbon, and increase the density of bricks.

Binding Agent

The commonly used binders for the production of MgO-C bricks are coal tar, coal pitch and petroleum pitch, as well as special carbonaceous resins, polyols, pitch-modified phenolic resins, synthetic resins, etc. The binders used are of the following types:

1) Bituminous substances. Tar pitch is a thermoplastic material with the characteristics of high affinity with graphite and magnesium oxide, high residual carbon rate after carbonization, and low cost. It has been widely used in the past; However, tar pitch contains carcinogenic aromatic hydrocarbons, especially benzoβ content. High; the use of tar pitch is now decreasing due to increased environmental awareness.

2) Resin substances. Synthetic resin is prepared by the reaction of phenol and formaldehyde. It can be well mixed with refractory particles at room temperature. After carbonization, the residual carbon rate is high. It is the main binder for the current production of MgO-C bricks. The glassy network structure is not ideal for thermal shock resistance and oxidation resistance of refractories.

3) Substances obtained by modification on the basis of asphalt and resin. If the binder can form a mosaic structure and in-situ carbon fiber material after carbonization, the binder will improve the high temperature performance of the refractory material.

Antioxidants

In order to improve the oxidation resistance of MgO-C bricks, a small amount of additives are often added. Common additives are Si, Al, Mg, Al-Si, Al-Mg, Al-Mg-Ca, Si-Mg-Ca, SiC, B4C , BN and recently reported additives such as Al-BC and Al-SiC-C [5–7]. The working principle of additives can be roughly divided into two aspects: one is from the point of view of thermodynamics, that is, at the working temperature, additives or additives react with carbon to form other substances, and their affinity with oxygen is greater than that of carbon and oxygen. , which is oxidized in preference to carbon to protect carbon; On the other hand, from a kinetic point of view, the compounds generated by the reaction of additives with O2, CO or carbon change the microstructure of carbon composite refractories, such as increasing the Density, blocking pores, hindering the diffusion of oxygen and reaction products, etc.

We Changxing Refractory Material Co.,LTD is professional manufacturer and supplier of refractory materials for more than 30 years. Our high quality ladle magnesia carbon brick are good sold to many countries say South Africa, Bangladesh, Indonesia, Malaysia, etc. Shall any interests, welcome to contact us. Our team would make best to be your reliable partner!

Article Source:Brief introduction of raw materials for production of magnesia carbon bricks
Company name: Henan Changxing Refractory Materials Co.,Ltd
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Corrosion of magnesia carbon brick by ladle slag

 In the ladle, due to the complex physical and chemical environment at the slag line, the furnace lining is the most vulnerable to damage. The chemical attack of steel slag on the?magnesia carbon brick?is mainly through the dissolution of magnesia and the oxidation of the graphite in the brick body. Under the combined action of the two factors, the magnesia carbon brick is damaged.?

1.The effect of alkalinity:?the lower the alkalinity of the slag, the more beneficial it is to the erosion of the?magnesia-carbon bricks. The increase of the alkalinity of the slag will reduce the activity of FeO in the slag, and the decrease of the activity of FeO will lead to the diffusion capacity of FeO.?

2.The influence of MgO:?Osbom et al. found that the MgO content in the reaction layer of the residual bricks of the LF slag line is very high. When the MgO content in the slag is low, the magnesia carbon The erosion rate of bricks is very large, and the lower the alkalinity, the faster the erosion of?ladle magnesia carbon bricks.?

3.The influence of Al2O3:?Al2O3 in the slag will reduce the melting point and viscosity of the slag, which greatly increases the penetration and erosion of the ladle magnesia carbon brick by the slag, and can also corrode the magnesia from the magnesia grain boundary to make periclase Dissociate.

4. The influence of FeO:?First, the FeO in the slag can easily react with the graphite in the magnesia-carbon brick at high temperature, and produce bright white iron beads to form a decarburized layer. Secondly, the magnesia will interact with the graphite in the slag FeO will form a low melting point of rich magnesium body. AT&S believes that in the process of repeated heating and cooling of the ladle, the phase transformation between the magnesium richite and the mafic ore is accompanied by the volume change, which causes cracks in the magnesia on the working surface, which in turn leads to the formation of magnesia. Dissolution, foreign studies believe that the increase in iron content in steel slag is detrimental to the life of magnesia-carbon bricks. Firstly, iron oxides accelerate the oxidation of graphite, and secondly, it increases the solubility of MgO in the slag and accelerates the dissolution of periclase. The combined effect of the two is the erosion of?magnesia carbon bricks.

Article Source:Corrosion of magnesia carbon brick by ladle slag
Company name: Henan Changxing Refractory Materials Co.,Ltd
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Some measures to improve the life of ladle slag line bricks

 1. Optimize the refined slag system

In the refining process, light-burned dolomite is added to increase the MgO concentration in the slag, increase the alkalinity and viscosity of the slag, control the amount of slag in the converter, and reduce the FeO content in the slag. The basicity of refining slag is controlled within the range of 4.2 to 5.0, the FeO content in the slag is controlled at about 0.5%, and the viscosity of the slag is adjusted at the same time. The MgO content in the slag is controlled at about 12%, which can effectively reduce the erosion of magnesia carbon bricks by the slag.

2. Improve slag line brick material

Studies have found that the higher the purity of magnesia used in ladle magnesia-carbon bricks, the less B2O3 in impurities, and the higher the carbon-sulfur ratio, the better the corrosion resistance of the lining bricks. It shows the effect of carbon content on the depth of slag line magnesia carbon brick melting loss. The main principle is that the oxidation in magnesia-carbon bricks is the oxidation of graphite in the bricks, and graphite has no wettability to slag, so magnesia-carbon bricks with high carbon content have better resistance to slag erosion.

Improve the material of the slag line magnesia carbon brick, select high-purity fused magnesia as the raw material, and control the carbon content at about 14%, which can effectively improve the corrosion resistance of the slag line.

3. Control the argon blowing system and power-on system

The LF furnace adopts the argon blowing mode that combines intelligent argon blowing and manual control. By manually controlling the intermittent stirring of the large argon gas, it promotes the heat transfer of the steel slag near the electrode and avoids the damage of the slag temperature here to the magnesia carbon brick of Siji Song Sexual erosion. The VD furnace uses a staged argon control mode. At the same time, the refined energization system should be controlled. At the beginning of energization, high-voltage and low-current long-arc operation is adopted, and after the slag is completed, low-voltage, high-current submerged arc operation is used.

4. Strengthen ladle operation control system and maintenance

During the production process, it is necessary to strengthen the operation control of the ladle, strengthen the turnover of the hot ladle, and reduce the excessive internal thermal stress caused by the non-continuous use of the ladle, which causes the magnesia carbon brick to crack or peel off. The slag line is close to the ladle mouth, and the temperature of the empty ladle is large. The production organization must be coordinated to reduce the steel ladle pressing rate, and at the same time strengthen the baking and maintenance of the ladle.

Article Source：Some measures to improve the life of ladle slag line bricks
Company name: Henan Changxing Refractory Materials Co.,Ltd
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Seamless ladle lining can reduce the unit consumption of refractory materials by 50%

 Magnesia carbon brick (MgO-C) has been used for many years as a refractory lining for ladle. In the 1980s, Japan developed a magnesia-aluminum spinel castable amorphous lining containing prefabricated spinel for use in ladle. In the 1990s, an in-situ spinel composition was formed in the second generation lining with fine magnesia and activated alumina added to the matrix. Different spinel castables are used in different ladle areas. At the bottom of the ladle, especially the ladle purging plug and wall bricks, the volume stability under high temperature and high pressure is the most important. High corrosion resistance and thermal shock resistance are also important in the process of high-speed molten steel production and when blowing in low-temperature stirring gas. Castables containing prefabricated spinel have become the standard for this application and provide optimal performance. The requirements for the side wall of the ladle vary. Since each steel cladding shell has some deformation after transportation, storage and processing, and because the inner lining is not absolutely rigid, one of the advantages is that stress relaxation can be used to avoid stress peaks causing cracks. Adding silicon powder to the castable formed by spinel to form a liquid phase will cause the castable to soften (a sharp drop in the RUL curve) to release thermal stress. The volume expansion caused by the in-situ spinel formation can close the seams on the surface. Therefore, the castable formed by spinel brings some advantages to the side wall of the ladle. This article believes that the combination of spinel and spinel is the best solution. This article provides a quick review of the ladle unshaped lining and innovative installation technology.

Advantages of unshaped lining for ladle:

(1) The replacement of magnesia carbon bricks with amorphous linings at the bottom and side walls of the ladle brings many advantages to the steelmaking process, mainly as follows:
(1) The use time of ladle is extended;
(2) The total number of ladle operations is reduced by 20%;
(3) Compared with MgO-C bricks containing toxic and carcinogenic substances (phenolic resin, coal tar pitch, etc.), the castable does not have any harmful materials;
(4) Reduce the unit cost of steel production;
(5) Produce ultra-low carbon steel in a better operating environment, because there is no carbon increase in the ladle refractories;
(6) The unit consumption of refractory materials is reduced by more than 50%.

Compared with other amorphous linings, the last advantage is the most important. Technically, the unit consumption of refractory materials is reduced by more than 50%, which is based on the concept of seamless lining. When magnesia-carbon bricks are used as the lining of the ladle and the service life of the bricks is reached, it will be replaced by a new set of MgO-C bricks. However, for amorphous linings, the situation is completely different. In the first installation, the amount of castable is the same as that of bricks. Subsequent replacement of the lining at the bottom and side walls, if brick lining is used, all need to be replaced. If unshaped refractory is used, only the part of the lining (about 40% to 60%) in contact with molten steel needs to be replaced, and the undamaged the lining will remain in place. Until the end of the ladle operation and before the complete renewal of all the inner?linings of the ladle, including the necessary safe working layer, refractory materials can be saved by using the unshaped inner lining.

Article Source:Seamless ladle lining can reduce the unit consumption of refractory materials by 50%
Company name: Henan Changxing Refractory Materials Co.,Ltd
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The magnesia carbon bricks specification

Magnesia carbon brick is a basic refractory made of magnesia and carbon material with asphalt or resin as binder. Magnesia refractory high refractoriness and carbon refractories are difficult to be slag, steel liquid wetting multiple advantages, because of its high refractoriness, slag erosion resistance is strong, excellent thermal shock resistance, and many other good characteristics and is widely used in steel industry, such as front of converter, electric furnace slag line parts and high temperature in the working layer of ladle, severe mechanical erosion, slag erosion condition of bad environment.

The magnesia carbon brick is easy to oxidize in high temperature and oxidizing atmosphere, which leads to the deterioration and looseness of brick structure, and finally erosion, spalling and failure. Therefore, it is necessary to add various anti-oxidants to inhibit the oxidation of carbon and improve the quality of magnesium carbon brick, such as adding boron carbide, metal aluminum powder, metal silicon powder and their mixtures.

Adding aluminium and silicon into magnesia carbon brick can increase the ability of resisting oxidation notably also, the strength at high temperature and the strength at normal atmospheric temperature with carbonization dealt at 1000℃ all have obvious increasement compared with the strenth of original brick. Now many countries are developing the production technique of magnesia-carbon brick.

Article Source:The magnesia carbon bricks specification
Company name: Henan Xinmi Changxing Refractory Materials Co.,Ltd
Email: info@cxrefractories.com
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Erosion of magnesia carbon brick in the ladle furnace

In the ladle, due to the complex physical and chemical environment of the slag line, the furnace lining is the most vulnerable to damage. The chemical attack of steel slag on the magnesia carbon brick is mainly through the dissolution of magnesia and the oxidation of the graphite in the brick body. Under the combined action of two factors, the magnesia carbon brick is damaged.

1. The effect of alkalinity: the lower the alkalinity of the slag, the more beneficial it is to the erosion of magnesia-carbon bricks. The increase in alkalinity of the slag will reduce the activity of FeO in the slag, and the decrease of FeO activity will lead to the diffusion capacity of FeO.

2. The influence of MgO: Osbom et al. found that the MgO content in the reaction layer of the residual bricks of the LF slag line is very high. When the MgO content in the slag is low, it will affect the refractory magnesia carbon brick. The erosion rate of bricks is very large, and the lower the alkalinity, the faster the erosion of magnesia carbon bricks.

3. The influence of Al2O3: Al2O3 in the slag will reduce the melting point and viscosity of the slag, which greatly increases the penetration and erosion of the magnesia carbon brick by the slag, and can also corrode the magnesia from the magnesia grain boundary, making periclase Dissociate.

4. The influence of FeO: Firstly, FeO in the slag easily reacts with the graphite in the magnesia carbon brick at high temperature, and produces bright white iron beads to form a decarburized layer as shown in Figure 1. Secondly, the magnesia will interact with the graphite in the slag. FeO will form a low melting point of rich magnesium. AT&S believes that in the process of repeated heating and cooling of the ladle, due to the phase transformation between the magnesium richite and the mafic ore accompanied by the volume change, the magnesia on the working surface will crack, which will lead to the formation of magnesia. Dissolution, foreign studies believe that the increase in iron content in steel slag is detrimental to the life of ladle magnesia carbon bricks. First, iron oxides accelerate the oxidation of graphite, and secondly, it increases the solubility of MgO in the slag and accelerates the dissolution of periclase. The combined effect of the two is the erosion of magnesia carbon bricks.

Article Source:Erosion of magnesia carbon brick in the ladle furnace
Company name: Henan Xinmi Changxing Refractory Materials Co.,Ltd
Email: info@cxrefractories.com
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Erosion mechanism of magnesia carbon brick in slag in LF

In the ladle, the chemical composition of?slag is complex and variable, and the temperature changes frequently, especially in the ladle slag line. Therefore, the magnesia carbon brick with excellent performance is often applied to the slag line. At demostic and abroad, the erosion mechanism of magnesia-carbon bricks in ladle in slag has been deeply studied. The detailed summary is as follows:

(1) Erosion of slag on magnesia carbon bricks:
In the ladle, due to the complex physical and chemical environment of the slag line, the lining of slag is most easily damaged. The chemical erosion of magnesia by the slag mainly through the dissolution of magnesium oxide and the oxidation of carbon in the matrix of magnesia carbon brick. Under the combined effect of the following factors, the damage of magnesia carbon bricks is caused:

1. The effect of alkalinity: the lower the alkalinity of the slag, the more favorable the erosion of the magnesia carbon brick. If the alkalinity of the slag is increased, the activity of SiO2 in the slag is lowered, the oxidation of carbon can be reduced, and the alkali degree increases, the activity of FeO in the slag decreases, which relatively slows the erosion behavior of the slag on the magnesia carbon brick.

2. The influence of MgO: When the composition analysis of the LF slag line was carried out, it was found that the content of MgO in the slag layer was as high as 30%, and the higher the content of MgO in the slag, the slower the erosion of the magnesia carbon brick and the higher the alkalinity. Also, the erosion of the slag on the magnesia carbon bricks is slowed down.

3. The influence of Al2O3: Al2O3 in the slag will reduce the melting point and viscosity of the slag, increase the wettability of the slag and the refractory material, make the slag more easily penetrate from the grain boundary of the magnesia, and remove the magnesite from the magnesia carbon brick matrix.

4. The influence of FeO: Firstly, FeO in the slag is easily oxidized with graphite in magnesia carbon brick at high temperature, and produces bright white iron beads to form a decarburized layer; then the periclase in the magnesia carbon brick is also in the same slag. The FeO reaction produces a low melting point product. During the repeated heating and cooling of the ladle, the thermal expansion coefficient between the formed magnesium iron composite low melting point product and the mafic iron is inconsistent, causing the magnesium oxide on the surface of the refractory material to be broken, thereby causing the dissolution of the brick body. Foreign scholars also believe that the increase of iron content in steel slag is not good for the life of magnesia carbon brick. First, iron FeO accelerates the oxidation of carbon on the surface of magnesia carbon brick, followed by FeO reaction with MgO, which makes the structure of magnesium carbon brick work surface loose. The combination of points will accelerate the erosion of magnesia carbon bricks.
(2) Oxidation of carbon in magnesia carbon bricks:
When the magnesia carbon bricks is in contact with the slag, the carbon will decarburize with the oxide such as FeO in the slag, and the decarburization layer is formed under certain conditions, so that the structure of the working surface of the magnesia carbon brick is loose, which is damaged by the magnesia carbon brick. main reason. The carbon reacts with oxides such as CO2, O2 and SiO2 and is continuously oxidized by the iron oxides in the slag; the loose structure formed by the second decarburization layer generates larger cracks and voids under the action of thermal expansion and slag, so that the slag is easily infiltrated. And forming a low melting point phase with MgO, and at the same time, the surface layer structure of the magnesia carbon brick changes under the action of the mechanical agitation of the molten pool and the violent erosion of the steel slag, and eventually the outer layer is gradually damaged, causing the magnesia carbon brick to be seriously damaged. After the temperature exceeds a certain value, the brick structure will be damaged and then sharply eroded, which is due to the self-consumption of MgO and graphite at high temperature.
(3) Influence of stomata
The erosion of magnesia carbon bricks is more likely to occur due to the presence of micropores inside and on the magnesia carbon brick. During the use of magnesia carbon bricks, the pores play an accelerating role in the formation of the decarburization layer, which in turn makes the erosion of the slag on the refractory polishing of the magnesia carbon bricks more serious. The outside air enters the pores in the magnesia carbon brick for cooling, and the oxygen in the air reacts with the surrounding carbon to produce CO gas and is discharged through the micropores. The continuous occurrence of the two processes causes the porosity and the pore size to gradually increase. The most important factor in the generation of pores is the choice of binder in magnesia carbon bricks. The binder is generally selected from phenolic resins. If a small amount of phenolic resin is added to the magnesia carbon brick, the porosity will not be too high in the cold state of about 3%, but the phenolic resin will decompose to produce water, argon, methane, carbon monoxide, carbon dioxide and the like after heating. And pores are formed under the flow of these gases, increasing the porosity. Therefore, the magnesia carbon brick is eroded by the slag passing through the pores, so that the oxidation of carbon and the dissolution of MgO are more intense, thereby causing damage to the magnesia carbon brick. Due to the repetitive nature of the gas generation process, the damage of magnesia carbon bricks is increasing.
Changxing refractory provides refractory products, calcium silicate products, castable & mortar, china refractory brick, ceramic fiber felt, ladle & tundish nozzle, ceramic fiber with high quality for you. Such as high alumina refractory bricks, magnesia carbon brick, clay refractory bricks and other refractory products.
Article Source:Erosion mechanism of magnesia carbon brick in slag in LF
Company name:Henan Xinmi Changxing Refractory Materials Co.,Ltd
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The refractories trend for EAF cover

Electric furnace cover with refractory material development trend is: brick - prefabricated block - the overall pouring. 

For alkaline fire brick cover, electric tile with magnets. In order to ensure the stability of the furnace cover structure and reduce the deformation and peeling of magnesia, the use of iron plaster or masonry insert iron. As the metal induced current (especially high power electric furnace cover), the formation of local overheating to non-magnetic steel fire brick, on the other hand pure magnesia brick linear expansion coefficient is too large, the amount of small. 

In addition, the whole pouring the cover. The use of the overall casting furnace cover to promote the life of the furnace to further improve. After the water is cooled, the electrode is also water-cooled around the electrode, and the high-alumina ultra-low cement castable containing 3% Cr2O3 is added from the material and the stainless steel fiber is added. The furnace cover is used in the case of slightly repaired 594 furnace and service life is 4 times than before.

Changxing refractory provides refractory products, calcium silicate products, castable & mortar, china refractory brick, ceramic fiber felt, ladle & tundish nozzle, ceramic fiber with high quality for you. Such as high alumina refractory bricks, magnesia carbon brick, clay refractory bricks and other refractory products.

Article Source：The refractories trend for EAF cover
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Construction of Converter Refractories

The converter is an upright cylindrical smelting furnace that does not require an external heating source and mainly uses liquid pig iron as a refractory raw material for steel making. According to the nature of the furnace lining refractory, it is divided into two types: acid converter and alkaline converter. According to the part of the gas blown into the furnace, it is divided into a bottom blowing, a top blowing, a side blowing and a top-bottom composite blowing converter. Bottom blowing, top and bottom composite blowing converter bottom design breathable fire bricks. When laying, you need to locate the position of the ventilation bricks. The bottom blowing and side blowing blowing furnace bottoms are not designed with ventilated bricks, and the bottom of the furnace is relatively simple.
According to the bottom drawing of the converter, the production of magnesia carbon bricks for the bottom of the furnace is arranged, and each type of brick is used for production. The center brick of the bottom is processed bricks. According to the physical and chemical indicators of the design materials, the appropriate magnesia carbon bricks are selected for bonding processing. After processing, the cross reference line shall be drawn on the plane of the upper part of the center brick to provide a reference for positioning the ventilating bricks in the subsequent pre-laying and determining the position of the steel side and the steel side.
Breathable bricks need to be pre-made models. The model is generally made of wood. If the size is too small, it can be replaced by other refractory materials such as magnesia carbon brick. When processing ventilated bricks, special attention should be paid to technical indicators such as slightness, diagonal difference, and distortion. The dimensional deviation of the permeable brick directly affects the masonry of the steel mill. When making a ventilated brick mold, the dimensional tolerance should be controlled as a negative rule as much as possible. If it is a square rule, the steel factory may have a large gap around the ventilated brick.
In addition to the above refractory materials, it is also necessary to prepare sand at the bottom of the furnace (3mm-1mm), grinding tools, cutting machines, rubber hammers and other auxiliary materials.
Article Source:Construction of converter refractories
Company name:Henan Xinmi Changxing Refractory Materials Co.,Ltd
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Some measures to improve the life of ladle slag line bricks

1. Optimize the refined slag system

The light burned dolomite is added during the refining process to increase the MgO concentration in the slag, increase the alkalinity and viscosity of the slag, control the amount of slag under the converter, and reduce the FeO content in the slag. The alkalinity of the refining slag is controlled in the range of 4.2~5.0, and the FeO content in the slag is controlled at about 0.5%. At the same time, the viscosity of the slag is adjusted, and the MgO content in the slag is controlled at about 12%, which can effectively reduce the erosion of the slag on the magnesia carbon brick.

2. Improve slag brick material

The higher the purity of magnesia used in magnesia carbon bricks, the less B2O3 in impurities, and the higher the corrosion resistance of lining bricks when the proportion of carbon to sulfur is high.

The material of the slag-line magnesia carbon brick is improved, and the fused magnesia with high purity is used as the refrafctory raw material, and the carbon content is controlled at about 14%, which can effectively improve the corrosion resistance of the slag line.

3. Control the argon blowing system and the power supply system

The LF furnace adopts an argon blowing mode combining intelligent argon blowing and manual control. By manually controlling the intermittent stirring of large argon gas, the heat transfer of the steel slag near the electrode is promoted, and the slag temperature is too high to cause destructive erosion of the magnesia carbon brick. The VD furnace uses a staged argon control mode. At the same time, the refining and energizing system is controlled. When the power is turned on, the high voltage and low current long arc operation is adopted. After the slag is formed, the low voltage and high current submerged arc operation is used.

Article Source:magnesia carbon bricks
Company name:Henan Xinmi Changxing Refractory Materials Co.,Ltd
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The advantages of Magnesia Carbon Brick

Changxing Refractory is able to manufacture magnesia carbon brick for every ladle, EAF, and BOF. We will design you a well-balanced lining, providing optimal performance at the lowest possible cost. Our magnesia-carbon brick is made from more than 98% electrically fused magnesite, high purity graphite and metallic antioxidants as needed. Size and specification can be tailored according to furnace type.

Changxing Refractory’s magnesia carbon brick factory is located in the magnesium capital of China, and products with high bulk density and low porosity.

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.

Advantages:

Magnesia carbon brick has excellent corrosion resistance together with good thermal shock properties.
Magnesia carbon brick offers good oxidation resistance due to use of high purity flake graphite.

Application:

Magnesia carbon brick is widely used in Electric Arc Furnace sidewalls, converters, hotspots and coldspots, and ladle furnace slag lines.
Specific Application:The lining and tap hole of Steelmaking Convertor, the sidewall and slag line of High Power Electric Arc Furnace and ladle slag line.
Article Source:Magnesia Carbon Brick
Company name:Henan Xinmi Changxing Refractory Materials Co.,Ltd
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Application of MgO-C bricks in ladle

Currently, inhibition of steel temperature droping has become a major issue for many steel plants. Therefore, in order to suppress temperature drop of molten steel, there has a test to study insulation problem of refractory lining in 185t ladle, by comparing three different measures.

First: Reducing the heat transfer effect of sidewall castables (30% reduction). This method is by reducing coarse particles in refractory castable, increasing porosity and other measures to reduce the thermal conductivity, to suppress heat dissipation.

Second: Using insulation materials in the backlayer of wall castable. This method is to use one layer insulating bricks with less than 1W (m℃) thermal conductivity between ladle steel shell and wall castable, to inhibit heat dissipationheat.

Thrid: Reducing the heat transfer of slag line MgO-C brick heat transfer (30% reduction). This method is developed in recent years, to select lower thermal conductivity of MgO-C brick from the high thermal conductivity of magnesia carbon brick for slag line, to suppress heat dissipation.

After comparing, the results found that: only in reducing the thermal conductivity of slag line magnesia carbon bricks , the effect of suppressing steel temperature dropping is significant, up to 2℃. The durability is same or higher than ordinary ladle, less cracks, the residual condition after use is also very good.

Changxing refractory provides refractory products, calcium silicate products, castable & mortar, china refractory brick, ceramic fiber felt, ladle & tundish nozzle, ceramic fiber with high quality for you. Such as high alumina refractory bricks, magnesia carbon brick, clay refractory bricks and other refractory products.

Article Source：Application of MgO-C bricks in ladle
Company name:Henan Xinmi Changxing Refractory Materials Co.,Ltd
Email: sales1@chinafirebrick.com
Website:http://www.chinafirebrick.com/

Development of ladle lining refractory materials

20th Century 50--70 years, China's steel plants mainly used aluminosilicate refractory materials, including clay, high alumina brick and so on. Since the 1980s, China has successively developed the aluminum-magnesium carbon, coal quality calcium and magnesium and other several series of new steel package refractories. Wherein the aluminum-magnesium carbon refractory materials are of varieties, all specifications, is China's major ladle refractories.

In earliest 20th Century 50--60 years, a variety of clay bricks were mainly used in our country. Due to low cost, until the 1980s, some steel plants were using clay bricks as ladle lining material. Although clay bricks is no longer used as ladle material so far, it had made a great countribution for recovery and future development of China's steel industry in the early days.

With the continuous development of steelmaking technology, steel quatity and quantity, clay bricks was no longer used because of short service life. Some of our mills started using a variety of high alumina bricks as ladle lining material, in which way the ladle life got a greatly improvement.

With the continuous improvement of steelmaking technology, high aluminum ramming mass, wax brick, alumina magnesia, aluminum-magnesium casting material, aluminum-magnesium unfired brick, aluminum-magnesium spinel castable, aluminum MgO-C, magnesium aluminate spinel brick, aluminum-magnesium unfired brick and a series of high-grade refractory materials appeared to adapt to higher demand.

Changxing refractory provides refractory products, calcium silicate products, castable & mortar, china refractory brick, ceramic fiber felt, ladle & tundish nozzle, ceramic fiber with high quality for you. Such as high alumina refractory bricks, magnesia carbon brick, clay refractory bricks and other refractory products.

Article Source:Development of ladle lining refractory materials
Company name:?Henan Xinmi Changxing Refractory Materials Co.,Ltd
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Performance advantages of corundum castables prefabricated parts

1) Advanced: The bottom of the ladle is lined with corundum spinel prefabricated bricks, which has a significantly improved performance compared with the traditional alumina magnesia carbon bricks, and solves the problem of low life of traditional alumina magnesia carbon bricks under LF refining conditions;

2) Comprehensive masonry realizes long life and economy of ladle: Since the refining of ladle is LF, it is necessary to ensure synchronization with the long life of the slag line. It also reduces the loss of refractory raw materials, taking into account the long life and economy of the ladle;

3) Small pollution to molten steel: The refractory material used is excellent in scour resistance and erosion resistance, and the amount of refractory material entering the molten steel per furnace is small, and the pollution to molten steel is small;

4) High construction flexibility and effective control of working time; high thermal intensity.

The corundum castable prefabricated parts are characterized by high-temperature strength, which is greatly improved compared with the previous precasts.
Changxing refractory provides refractory products, calcium silicate products, castable & mortar, china refractory brick, ceramic fiber felt, ladle & tundish nozzle, ceramic fiber with high quality for you. Such as high alumina refractory bricks, magnesia carbon brick, clay refractory bricks and other refractory products.

Article Source:Performance advantages of corundum castables prefabricated parts
Company name: Henan Xinmi Changxing Refractory Materials Co.,Ltd
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Effect of magnesia on refractory materials

Magnesia properties are divided into chemical and physical properties. The chemical properties of magnesia mainly refer to MgO as the main component. Periclase MgO is one of the common minerals in cement clinker, therefore, periclase has good corrosion resistance to cement clinker.

The physical properties of magnesia make refractory materials in cement rotary kiln often exhibit the following phenomena:
1. The Periclase MgO has a high melting point, so many magnesia refractories have quite high temperature resistance;
2.The magnesia has good thermal conductivity. When the high-MgO refractory raw material is used and the kiln skin is not attached, then the surface temperature of the kiln body rises. At this time, not only the heat loss is large, but also the kiln body is easily burned out;
3.The Periclase MgO has a high thermal expansion coefficient, which causes the insufficient thermal shock resistance of the magnesia refractory material. During use, the magnesia refractory material often peels off.

Changxing refractory provides refractory products, calcium silicate products, castable & mortar, china refractory brick, ceramic fiber felt, ladle & tundish nozzle, ceramic fiber with high quality for you. Such as high alumina refractory bricks, magnesia carbon brick, clay refractory bricks and other refractory products.

Article Source: Effect of magnesia on refractory materials
Company name: Henan Xinmi Changxing Refractory Materials Co.,Ltd
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The details of magnesia carbon brick

Magnesia carbon brick is a refractory consisting of MgO at 80-85% or more, with magnesite as the main mineral. The raw material of Magnesia carbon brick is mainly magnesite, the basic component is MgC03, after high temperature calcination into sintered magnesite, and then broken into a certain size after sintering magnesia (also known as metallurgical magnesia). Magnesia is widely used as a furnace material, refractory ramming material, containing less magnesium magnesia, as the manufacture of refractory raw materials of magnesia fire brick. Natural magnesite resources are few, China's reserves and production rank the forefront of the world. Many countries that lack magnesite rely on magnesia made from seawater, and the cost is high.

Magnesia carbon bricks according to their different production processes, divided into two kinds of sintered magnesia and chemical combination of magnesia brick. Sintered magnesia is used to burn, the size of particles with the appropriate proportion of magnesia, adding brine (MgCl2 aqueous solution) and sulfite pulp waste as a binder, press molding, in the 1550-1650 ℃ high temperature firing. In the firing process, the impurities in the magnesite and the addition of liquid phase, the magnesia carbon brick bonded together. And the chemical combination of magnesia carbon brick is not through the firing process, the sintered magnesite according to the proportion of grain with a good amount, adding the right amount of mineralizer and binder, press molding, after drying is finished. Chemical combination of magnesia carbon brick strength is low, the performance is not as good as sintered magnesia, but the price is cheap, less than half the price of sintered magnesia. It is used in the performance requirements are not too high parts, such as heating furnace and soaking furnace bottom.

Chinafirebrick provides refractory products, calcium silicate products, castable & mortar, china refractory brick, ceramic fiber felt, ladle & tundish nozzle, ceramic fiber with high quality for you. Such as high alumina refractory bricks, Magnesia Carbon Brick, clay refractory bricks and other refractory.

Article Source:Magnesia Carbon Brick
Company name: Henan Xinmi Changxing Refractory Materials Co.,Ltd
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Ordinary sintering magnesia brick production process

The firing process usually includes magnesia carbon brick crushing, grinding, grading, batching, mixing, molding, drying and sintering processes.

1) refractory raw material requirements. Chemical composition of sintered magnesia: MgO>87%, CaO = 2.5%, SiO2 = 5%, the appearance of brown or dark brown, dense crystal, good sintering, bulk the density is larger than 3.2g/cm3, igloss <0.3%, in order to ensure the product has good structure, control C/S<0.5.

2) particles should be considered with the most compact principle. The current domestic production of ordinary sintering magnesia brick has various forms according to the actual situation, some using mixed ingredients, the single sieve, the critical particle size 3mm or 2mm, some with three ingredients of 3 ~ 1mm, 1 ~ 0mm, <0.088mm also according to the actual size of refractory brick type and the critical particle size can be enlarged to 6mm, while using four or five ingredients. In order to improve the thermal shock resistance of products, may be appropriate to increase the critical particle size, or by increasing the large particle size. In order to improve the product load softening temperature and sintering, can be increased when the content of fine powder particles, reduce the upper limit.

3) Ingredients. In a factory three ingredients for example: 3 ~ 1mm, 40 ~ 50%; 1 ~ 0mm, 20 ~ 25%; less than or equal to 0.088mm, 30 ~ 35%. binder commonly used sulfite liquor or brine, adding amount of 4% ~ 6%, adding the waste brick, the general should be <20%.

4) Mixed. Usually, in the wet grinding machine in the order of operations: coarse grain - size - bond - fine powder, net mixing time of >15 minutes, mud water <3%, generally do not need trapped material.

5) The magnesia material for forming poor materials, easy molding, blank containing water less, at around 2.5%, low mud plasticity, should adopt high pressure molding, control body density >2.95g/cm3.

6) Dry. Make the body moisture <1%. if not high water content in the body, can take the natural drying, generally >24 hours. If using drying, it generally takes 8 to 12 hours should not be too high, the drying temperature, inlet and outlet temperature control, so as to avoid cracking.

7) Firing. In the heating process will change as follows: out of the water, the generation of liquid phase sintering, particle migration, solid phase reaction, recrystallization, and finally sintering. Strength is increased and the density increases. The firing temperature is generally 1500 to 1600 degrees centigrade.

Article Source: Ordinary sintering magnesia brick production process
Company name: Henan Xinmi Changxing Refractory Materials Co.,Ltd
Email: sales1@chinafirebrick.com
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