The Development Of Refractory Material

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In recent 20 years, the development of refractory industry has been promoted by the implementation of a series of technical policies, such as the large scale of blast furnace, the oxygenation of steelmaking, the externalization of refining furnace, the continuous casting ingot and the automation of operation. Refractory materials, especially unshaped refractories and refractory fiber development is rapid, the use of universal; refractory production technology and automation level, as well as the work of labor and material, Productivity has been improved.
    The unshaped shape refers to the unshaped refractory material including the refractory mud, the high aluminum brick includes the high alumina brick, the corundum brick and the mullite brick and so on, the alkali brick refers to the magnesia brick, the magnesia chrome brick, the dolomite brick and the square Magnesite bricks and so on. The United States and the production of about 400 million tons in Japan, but also a substantial decline in the trend; alkaline brick production accounts for the proportion of the total refractory material production is not the least change in the United States and Japan's production of refractory material production capacity of more than 10 million tons; , Generally 10-21%; the proportion of silica brick decreased slightly, the proportion of high-alumina brick slightly increased, mainly corundum brick and mullite brick production increased due to; silicon carbide brick, graphite brick, carbon brick And zirconium brick and other varieties, the rapid development of its proportion is generally 2-8%; clay brick and other refractory materials will be greatly reduced production; has been hailed as the second generation of refractory unshaped refractories, the pace of development The fastest, fifteen years, its production has risen to account for the total output of refractory 1/3 or so, some countries have reached 40% or more, and the proportion of fired refractory roughly the same.
    In addition, has been hailed as the third generation of refractory fiber refractories, from around 1970, has been high-speed development. In 1969 the world production of refractory fiber is about ten thousand tons, to 1979 has reached 45000 tons. At present, the United States production capacity of refractory fiber 2.5-3.0 million tons / year, the United Kingdom 6000-8000 tons / year, Japan is about 8,000 tons / year, the Soviet Union roughly 6000 tons / year, China is about 3,000 tons / year. At the same time, the production methods and secondary processing technology of refractory fiber have also been greatly improved, the variety is increasing, the use temperature is raised from 1000 ℃ to above 1600 ℃, and the construction technology has also made great progress.

In recent 20 years, the development of refractory industry has been promoted by the implementation of a series of technical policies, such as the large scale of blast furnace, the oxygenation of steelmaking, the externalization of refining furnace, the continuous casting ingot and the automation of operation. Refractory materials, especially unshaped refractories and refractory fiber development is rapid, the use of universal; refractory production technology and automation level, as well as the work of labor and material, Productivity has been improved.

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The Performance Of Chrome Corundum Brick

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Properties and Application of Chromium Corundum Brick.
Fire resistance of the product
In the high-purity corundum material by adding Cr2O3, regardless of the amount of how much, not only will not reduce the fire resistance of materials, but to improve the fire resistance of materials. Chromite corundum bricks (> 1790) are superior to high purity corundum products in terms of fire resistance and load resistance (> 1700!).
1. The strength of the product
Room temperature compressive strength of high purity corundum brick is usually 70 ~ 100MPa, room temperature high compressive strength of high-performance chrome corundum brick is generally greater than 150MPa, the intensity was significantly higher than corundum brick. This is because the products in the combustion process, between particles and particles, particles and fine powder, powder and powder formed between the Al2O3-Cr2O3 solid solution, solid solution particles and fine powder particles together, so that the strength of the material to achieve greatly increased.
2. Thermal shock resistance
When the Cr2O3 content is 10% to 66%, Cr2O3 is added to the corundum. Raw materials Chromium Corundum series of products using alumina and chromium oxide with a certain proportion of high-temperature melting after the synthesis of solid solution

Properties of Chromium Corundum Brick.

Fire resistance of the product

In the high-purity corundum material by adding Cr2O3, regardless of the amount of how much, not only will not reduce the fire resistance of materials, but to improve the fire resistance of materials. Chromite corundum bricks (> 1790) are superior to high purity corundum products in terms of fire resistance and load resistance (> 1700!).

1. The strength of the product

Room temperature compressive strength of high purity corundum brick is usually 70 ~ 100MPa, room temperature high compressive strength of high-performance chrome corundum brick is generally greater than 150MPa, the intensity was significantly higher than corundum brick. This is because the products in the combustion process, between particles and particles, particles and fine powder, powder and powder formed between the Al2O3-Cr2O3 solid solution, solid solution particles and fine powder particles together, so that the strength of the material to achieve greatly increased.

 

2. Thermal shock resistance

When the Cr2O3 content is 10% to 66%, Cr2O3 is added to the corundum. Raw materials Chromium Corundum series of products using alumina and chromium oxide with a certain proportion of high-temperature melting after the synthesis of solid solution

 

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The Melting Technology Of Fused Cast AZS Block

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Melting AZS block melting technology is divided into reduction and oxidation.
Reduction method, also known as submerged arc method, is the graphite electrode immersed in the furnace charge, because the electrode in the oxygen shortage of combustion, recovery of a series of recovery reactions, so that some high-oxide melt instability, together with the carbon Also into the melt, which will eventually melt the color black.
In the ablation process, the charge charge of the circuit is not carburizing or melting impregnation, carbon decarburization before casting, which makes the melt without carbon technology, known as oxidation, also known as the arc method. Because of the existence of carbon in AZS recovery method, when used in the glass kiln, high-temperature combustion of carbon, the gas will be squeezed out of the soft glass phase, accelerating the corrosion of glass on the brick, so the presence of carbon corrosion resistance AZS bad, Now more choice of oxidation rather than recovery methods, AZS charcoal in the history of the main graphite electrode during the discharge will not use the arc into the furnace, so need to find a way to prevent coal into the furnace. Here are a few common ways:
Long arc method
The electrode does not melt in the furnace and eliminates carbon transfer between the electrode and the melt.
Add oxidizer method
Some oxygen enrichment is added to the constituent material, which releases oxygen during the melting process. The molten liquid evaporates on the surface of the carbon combustion, but is usually smelted by a bright arc, with arc melting during the refining process.
Through the oxygen method
There are a lot of the same methods, but the oxygen is blown back after melting. Some will oxygen lance pierced from the roof, a number of oxygen gun placed in the mouth, so that the furnace forward melting submerged tube oxygen lance, a trace of molten carbon melt contact with oxygen escape.

Fused cast AZS block's melting technology is divided into reduction and oxidation method.

Reduction method, also known as submerged arc method, is the graphite electrode immersed in the furnace charge, because the electrode in the oxygen shortage of combustion, recovery of a series of recovery reactions, so that some high-oxide melt instability, together with the carbon Also into the melt, which will eventually melt the color black.

In the ablation process, the charge charge of the circuit is not carburizing or melting impregnation, carbon decarburization before casting, which makes the melt without carbon technology, known as oxidation, also known as the arc method. Because of the existence of carbon in AZS recovery method, when used in the glass kiln, high-temperature combustion of carbon, the gas will be squeezed out of the soft glass phase, accelerating the corrosion of glass on the brick, so the presence of carbon corrosion resistance AZS bad, Now more choice of oxidation rather than recovery methods, AZS charcoal in the history of the main graphite electrode during the discharge will not use the arc into the furnace, so need to find a way to prevent coal into the furnace. Here are a few common ways:

Long arc method

The electrode does not melt in the furnace and eliminates carbon transfer between the electrode and the melt.

Add oxidizer method

Some oxygen enrichment is added to the constituent material, which releases oxygen during the melting process. The molten liquid evaporates on the surface of the carbon combustion, but is usually smelted by a bright arc, with arc melting during the refining process.

Through the oxygen method

There are a lot of the same methods, but the oxygen is blown back after melting. Some will oxygen lance pierced from the roof, a number of oxygen gun placed in the mouth, so that the furnace forward melting submerged tube oxygen lance, the melt of the trace carbon combustion escapes by contact with oxygen.

 

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The Property And Usage Of Magnesia Brick

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Refractoriness of magnesia brick high reaches above 2000 ℃, and refractoriness under load with the combination of phase's melting point and at high temperatures result in different liquid phase without great changes. General magnesia brick's load softening temperature is at 1520 ~ 1600 ℃, and high purity magnesium boast a softening start temperature can reach 1800 ℃.

The difference between start refractoriness under load of magnesia brick and collapse of temperature is not big, it is because the main phase composition is periclase magnesia brick, but periclase crystals within the magnesia brick is not crystalline network skeleton, but was cemented by combination. High purity magnesia brick's refractoriness under load start temperature can reach 1800 ℃, mainly due to the combination between the periclase grain is forsterite or dicalcium silicate, it and MgO formed eutectic mixture's melting temperature is high, crystal lattice strength is big and plastic deformation under high temperature is small, crystal particles combined are good.

The linear expansion rate of magnesia brick under 1000 ~ 1600 ℃ is generally 1.0% ~ 2.0%, and approximate or linear, in refractory products, thermal conductivity of magnesite brick is next only to carbon brick, it reduces by the rise of temperature. Under the condition of 1100 ℃ water, magnesia brick's number of thermal shock is only 1 ~ 2 times. Magnesia brick to CaO and iron oxide's alkaline slag  resistance capability is strong, but to SiO2 and acidic slag's resistance is weak.

So in use can not direct contact with silica brick, and in general will be separated with a neutral brick. Under normal temperature, the conductivity of the magnesia brick is very low, but at high temperature, the conductivity will not be ignored. Property of magnesia brick, because of the differences of adoptive raw materials, production equipment, technology measure have a large difference.

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The Characteristics And Application Scope Of Ceramic Fiber Board

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Characteristics

Ceramic fiber board product quality of a material is solid, good toughness and strength, has excellent ability to resist wind erosion. Heating is not inflation, qualitative light, construction is convenient, can be arbitrary bending shear, is ideal energy-saving materials of kiln, pipe and other insulation equipment.

1. High crushing strength, long service life.

2. Low thermal capacity, low thermal conductivity.

3. Non- brittle material, good toughness.

4. Size precision, good flatness.

5. Easily cut installation, construction is convenient.

6. Excellent resistance to wind erosion performance.

7. Continuous production, uniform fiber distribution, stable performance.

Application scope

1. The back lining of cement building materials industry kiln keep warm.

2. Petrochemical, metallurgy, ceramics, glass industry kiln back lining keep warm.

3. Heat treatment furnace back lining keep warm.

4. The non-ferrous metal industry back lining keep warm.

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How To Judge The Quality Of Fire Clay Brick

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Fire clay brick accounts for an important position in the refractory industry. The most important feature of fire clay brick is that the raw materials can be obtainded locally.

Fire clay brick is cheap and durable. It can be used for fire protection, thermal insulation, sound insulation and moisture absorption. Therefore, it is widely used in industrial production. The scrap bricks can be reused as aggregate.

When purchasing fire clay bricks, some professional knowledge is needed and some principles should be followed.

1) Take your need into account, such as specifications and materials.

2) Select appropriate manufacturers. Shop around and capare the price before you buy. Also pay attention to the credibility of manufacturers, after sales service, product quality and service attitude.

3) After selecting a manufaturer, give a visit to the factory to understand the strength of manufacturers, scale, production qualification, production capacity and evaluation on the product from other customers.

4) Pay attention to the proper use of fire clay brick in the production and the implementation of safety measures so as to make full use of fire clay brick, reduce unnecessary losses, extend the service life ansd reduce the cost.

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The Use Of Silica Brick In The Glass Furnace

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Since the silica brick has low price, high purity, high softening temperature under load, no pollution to glass liquid and good resistance to R2O gases and aicd gases, it is widely used in the crown of the glass furnace, the upper part of the suspended wall, the back wall and the front wall.

The SiO2 content in the silica brick used in the glass furnaces should be controlled. And it should be mainly composed of cristobalite. For large glass furnaces and oxy-fuel glass furnaces, refractory materials with high purity, good creep resistance and good corrosion resistance are used.

Since the advent of brick, there are three types of brick. The first is the common silica brick. the second is high quality silica brick. the third category is improved high quality silica brick.

With the development of glass mleting technology, silica bricks with better performance are required.

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Applications Of Fire Clay Bricks

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Fire clay brick plays a versatile role in the many industries.

Fire clay brick can be used in the metallurgical industry. Fire clay materials including shaped refractory materials and unshaped refractory materials acount for about 70% of the total refractory materials. Hard clay is used to produce refractory materials for theblast frunace, hot stove, ladle lining brick and plug brick.

High-alumina clay is used to produce alumina bricks for electric furnaces and blast furnaces, high aluminum lining brick and high alumina refractory mud. Hard clay and high alumina clay are often calcined into clinker at high temperature (1400 - 1800℃).

Refractory clay also has important roles in the grinding industry, chemical industry and ceramics industry. High-alumina clay can be made into abrasive materials by melting in an electric arc furnace. Fused corundum abrasive material is currently the most widely used an abrasive material. It acounts for 2/3 of the total abrasive materials.

High alumina clay can be used to produce a variety of aluminum compounds such as aluminum sulfate, aluminum hydroxide, aluminum chloride, aluminum potassium sulfate and other chemical products. In the ceramic industry, hard clay and semi-hard clay can be used to manufacture household porcelain, construction porcelain and industrial porcelain.

In the construction materials industry, refractory clay can be used to produce high alumina bricks, phosphate high alumina refractory bricks and high alumina fused cast bricks. High-alumina clay can be made into aluminum-containing cement by calcining and then mixing with limestone. This quick-setting cement has strogn heat and corrosion resistance.

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Applications Of Fused Cast AZS Block

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Fused cast AZS block is made of high pure raw materials in a special electric arc furnace by the casting process of long arc melting and oxidation treatment. There is almost no carbon contamination from the electrodes.

Due to the casting process and high pure materials, fused cast AZS block has super strong corrosion resistance to the glass liquid and low potential of pollution.

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How To Store Ceramic Fiber Board

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Ceramic fiber board is a high-strength refractory fiber board made of ceramic fiber. It is an essential high temperature refractory material. Ceramic fiber board must be stored properly to fulfill its high temperature properties.

Ceramic fiber board is made of ceramic fiber cotton by vacuum forming. It has tough texture, high strength, superior high temperature performance, excellent support force, good tensile strength and impact resistance. Its strength is better than the fiber blanket and vacuum formed felt. It will be gathered together when contact with water and its hardness will be decreased. In this case, it is easy to fall off when touched. So, waterproofing is very important for the storage of ceramic fiber board.

Ceramic fiber board should be stored in dry circumstances with no water and moisture. The building should be watertight and kept dry. Ceramic fiber board should have waterproof plastic film inside and be covered with cartons and placed on the ground with pallets. It should be placed on pallaets without contact with the ground, at least 20 mm away from the ground. In the rain season, ceramic fiber products should be covered with a waterproof canvas. Pay attention to water leakage if it is stored in iron house.

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