2016年6月29日星期三

Key Factors For The Casting Process Of Fused Cast AZS

The casting speed determines the casting time. Every casting products has its best casting time. Improper insulating castable casting time will cause many defects. If the casting speed is too fast, the stream will be coarse and the flowing speed will be too fast, which will produce big impact force on the mold. The force may destroy or melt the refractory brick mold and cause protrusions. Additionally, gas will be brought into the mold and produce a thin shell filled with gas and bubbles in the casting. Besides gas, raw materials in the furnace mouth may be brought into the melt and cause defects. Conversely, if the casting speed is too slow, it will produce defects such as loose corners, knots, sand and pouring shortage.
Back pour refers to the process of repouring some melt into the shrinkage cavities after the casting is completed. Generally, refractory brick for sale small bricks are solidified quickly and do not require back pour. Medium bricks can be repoured. Large bricks require back pour and it takes a long time. Back pour is one of the effective ways to reduce the shrinkage cavities and improve the bulk density.

Casting is an important step of the manufacturing process that has great influence on the quality of the fused cast AZS block. Key factors that affect the casting process of fused cast refractories AZS include the casting temperature, casting speed, the casting time and back pour.
The casting temperature is the temperature of the melt when it is poured into the mold. The casting temperature of fused cast AZS can be as high as 1820-1840℃. The viscosity of the melt is up to the chemical composition and temperature of the melt. The chemical composition is up to the formulation. The casting temperature is crucial since the higher the temperature, the lower the viscosity, the better the flow-ability. However, if the temperature is too high, the temperature difference between the casting and the mold is small, which will increase the shrinkage stress and cause cracks.

refractory company Henan Xinmi Changxing Refractory Material Co., Ltd. Located in Henan Province,China.ChangXing's product portfolio covers shaped products such as refractory materials,refractory brick, refractory castable,refractory nozzle, ceramic fiber, slide gate, etc; unshaped products including repair, construction and casting mixes and mortars.exported to more than 20 countries, such as Thailand, Indonesia, Pakistan, Saudi Arabia, South Africa, Turkey, Iran, Iraq and so on.

2016年6月26日星期日

What is Spun Ceramic Fiber Blanket

Ceramic Fiber Blanket
Ceramic Fiber Blanket
Spun ceramic fiber blanket has low thermal conductivity, low thermal capacity, excellent thermal stability and thermal shock resistance, excellent tensile strength, excellent thermal insulation, good fire protection and sound absorption. It can be used in industrial furnaces, heating devices,high temperature pipe lining, industrial high-temperature reaction equipment, heating equipment lining, power boilers, gas turbine, furnace door, and high-temperature filter materials.

The heat capacity of spun ceramic fiber blanket is only 1/10 of that of lightweight refractories lining and light castable refractory material lining. The heat capacity of the lining material is is proportional to its weight. Low heat capacity means less heat absorption of the furnace in the reciprocating operation and higher heating rate. It can greatly reduce energy consumption of the temperature operation control, refractory company especially the start and shutedown of the heating furnace.

Spun ceramic fiber blanket is made of spun ceramic fiber cotton by needling, heat setting, vertically and horizontally cutting and rolling. Ceramic fiber blankets with different thickness and density provide a wide range of choice of materials to obtain the best insulation and energy efficiency.
Spun ceramic fiber blanket has uniform diameter, long fiber and low content of slag balls. Its interleaving degree, delamination, properties, erosion ressitance, flexibility and tensile strength are all improved, which improves the application performance of spun blanket and reduces the material loss. Spun blanket does not contain any binding agent to ensure that products have good reliability and stability in various environments.

Henan Xinmi Changxing Refractory Material Co., Ltd. Located in Henan Province,China.ChangXing's product portfolio covers shaped products such as refractory materials,refractory brick , refractory castable,refractory nozzle, ceramic fiber, slide gate, etc; unshaped products including repair, construction and casting mixes and mortars.exported to more than 20 countries, such as Thailand, Indonesia, Pakistan, Saudi Arabia, South Africa, Turkey, Iran, Iraq and so on.

http://www.yilongrefractory.com/AllProductServlet?id=1&number=20

Refractory Application in the Walls of Glass Furnace Regenerators

Assembled Bricks for Blast Tuyere
Good abrasion resistance, good thermal shock stability, high temperature strength, good erosion resistance.

Application

It is widely used in Blast furnace tuyere, the circumference of the tube outlet, mixed air entrance, flue gas pipeline, turning tube etc..
Chemical corrosion is not as strong as in the checkers because refractory brick for sale are protected by the masonry and only one side is exposed to the chemical attack. Load is higher than on the overhung zones, but temperature is lower. Periclase based refractories, mullite and sillimanite bricks are suitable for this application.
Characteristics of this area are: high load, low temperature and a reduced chemical attack. Basic materials with 90-92 percent MgO, mullite, sillimanite and 44 per cent Al2O3 “super duty” are suitable for this application.
The internal separation walls are insulating castable fully immersed in the high temperature environment and therefore the operating conditions are severe. They must resist loading at high temperature, and thus they must have high values of refractoriness under load and therefore high creep resistance.
Basic materials are suitable within the temperature limits indicated in the top zone (1,460-1,480°C), while different grades of mullite according to the different zones of the separation wall can be used.

In the glass furnace, walls of the regenerators are used to limit thermal losses. The main operating factors to be considered are temperature, repeated temperature cycling, airborne particulates, volatiles and load. Fuel and glass composition must also be considered when deriving the refractory specifications.
The walls in four zones as with checkers are subjected to different conditions:
1) Top zone: from the crown skewbacks to one meter under first row of checkers;
2) Mid zone: from the end of the top zone to 1,000°C;
3) Condensation zone: from 1,000°C to 700°C;
4) Lower zone: from 700°C to the Bottom.
The operating conditions are the same as for the crown but with minor load. Low iron basic refractories with a high periclase content and high grade mullite (95-97 percent mullite) are suitable for this area. As far as basic refractories are concerned the operating temperature must be under 1,500°C (1,460-1,480°C) to avoid creep.
Provided the target wall is exposed to the same conditions as the other top zone walls, then the refractory material will be as for the rest of the top zone. However, in the event the target wall is subject to excessive waste gas impingement then fused cast AZS block is recommended.
Checkers protect the mid zone wall. Temperature and load are lower compared to the top area, thus basic ladle refractory refractories with 95 per cent MgO or a good mullite are suitable for this area.

refractory company Henan Xinmi Changxing Refractory Material Co., Ltd. Located in Henan Province,China.ChangXing's product portfolio covers shaped products such as refractory materials,refractory brick, refractory castable,refractory nozzle, ceramic fiber, slide gate, etc; unshaped products including repair, construction and casting mixes and mortars.exported to more than 20 countries, such as Thailand, Indonesia, Pakistan, Saudi Arabia, South Africa, Turkey, Iran, Iraq and so on.

http://www.yilongrefractory.com/AllProductServlet?id=1&number=20

2016年6月23日星期四

The Economy of Fused Cast Bricks in Glass Furnaces

Al2O3-SiC-C Brick for Hot Metal Ladle and Torpedo Car
Al2O3-SiC-C brick, with corundum, bauxite, silicon carbide and graphite as raw materials, phonetic resin as binder, added with expansive agent and modifying agent, is characterized by good thermal shock resistance, good erosion resistance, and non-sticking slag. It is used for torpedo car and hot metal ladle, and can meet request of customers.
The limit temperature of silica brick crown is 1600℃, while the fused cast AZS block can be used refractories safely in the 1680℃. AZS also has excellent corrosion resistance to fly ash and vapor firebrick refractory sale of volatile components. Therefore, the temperature of the furnace can be increased to 100℃. Ina addition, there is a low risk of burning of materials. The crown is low, which increases the heat radiation and improve the melting rate and reduce the energy consumption.
Since 1965, the fused cast AZS crown high insulating brick has been used. The crown was initially built with common silica brick, mainly used in the glass fiber and borosilicate glass melting furnace. The fused cast AZS crown as well as the insulation method began to be actually used and its application was even expanded to large soda lime glass melting furnaces. In 1974, the structure was used in large cross-fired furnaces with a span of 11m. Besides, it is also used in the container glass furnace in castable refractory material France and can reduce 130 liters heavy oil per ton.

Fused cast AZS block has been used in the checker work of the regenerator and the crown in the glass furnace.
Fused cast AZS block has excellent resistance to the erosion by fly ash to the checker brick in the regenerator, which is confirmed by its application in the burner. Fused cast AZS is durable refractory fiber board than other bricks even it is only used in the upper layer of the checker work.
The performance of fused cast AZS block in the crown has been confirmed in the furnace with a small span. It shows excellent resistance. The new fused cast AZS crown structure as well as the insulation method developed by R.E.R from France has been used in the glass furnaces with a span of 11m and large furnaces. It is characterized by the use of light and firm magnetic structure and complete insulation with a 500mm insulation layer.


Henan Xinmi Changxing Refractory Material Co., Ltd. Located in Henan Province,China.ChangXing's product portfolio covers shaped products such as refractory materials,refractory brick, refractory castable,refractory nozzle, ceramic fiber, slide gate, etc; unshaped products including repair, construction and casting mixes and mortars.exported to more than 20 countries, such as Thailand, Indonesia, Pakistan, Saudi Arabia, South Africa, Turkey, Iran, Iraq and so on.

Bonded Again Fused Cast Alumina Block

Clay, Aluminum Refractory Mortar
Bonded again fused cast alumina block is a type of bonded again sintered refractories brick made of fused corundum clinker as the granular material and fused corundum or sintered

corundum powder as the matrix.

The batching of granular materials should be according to the principles of tightly packing, multilevel ratio, refractory company less intermediate particles and more fine powder. This can improve

the density and sintering of the products. The additives include aluminum phosphate, phosphoric acid, aluminum chromium phosphate, cellulose and pulp waste solution. Among them,

he most promising is active phosphate. Recently, ammonium phosphate is on the trial and achieves good magnesia carbon brick results. The mud should be mixed evenly with a moisture content of 3-4%.

After high pressure molding, high dense bricks are obtained.

There are a few harmful ingredients in the corundum which will cause poor sintering or cracking, firebrick refractory sale so corundum should be pre-calcined before use. The residual ferro-silicon alloy

is oxidized and decomposed into Fe2O3 and SiO2 at 500-1000℃ and Ti in the minerals can be oxidized into TiO2 (rutile), which can cause large volume expansion. After pre-

calcining, the stress caused by those decomposition reactions and oxidation reactions can be eliminated during the pre-calcining process and cracks caused by the volume

expansion of those impurities can be avoided during the sintering process.
Fused corundum block has large volume, so it should be smashed with drop hammers and other ways and then high insulating brick pulverized. The pulverized fused corundum is stored by size after

screened. Fused corundum is hard and difficult to grind. Therefore it is wet ground by ball mills or vibration ball mills. The grain size can be less than 40μm or even 10μm.

The iron in the granular material can be removed with electromagnets and the iron in the fine powder can be washed with acids.


When using fused brown corundum or white corundum as raw materials, the frits should be smashed and then processed by removing the ferro-silicon alloy and other impurities.

White corundum should be processed by removing the flaky sodium aluminate crystals and other low-melting substances. The impurities are easy to be identified since they have low

density and float in the surface of corundum frits.

The fused cast alumina block has high purity. It is difficult to sintere and should be sintered at 1800℃. The type of the kilns used depends on the production scale. For small

batch production, high-temperature batch kiln is better. For batch stable production, the small high-temperature tunnel kiln is used.

Henan Xinmi Changxing Refractory Material Co., Ltd. Located in Henan Province,China.ChangXing's product portfolio covers shaped products such as refractory materials,refractory

brick, refractory castable,refractory nozzle, ceramic fiber, slide gate, etc; unshaped products including repair, construction and casting mixes and mortars.exported to more

than 20 countries, such as Thailand, Indonesia, Pakistan, Saudi Arabia, South Africa, Turkey, Iran, Iraq and so on.

2016年6月6日星期一

Properties and applications of fused cast AZS

Chrome Corundum Abrasion Resistance Prefabricated Part for Heating Furnace
The products are produced by corundum and chromium oxide as main materials, formed from casting, after being treated under high temperature, it has high hot strength and good wear resistance, suitable for making the slide rail part of heating furnace.
Fused cast AZS block is tundish well block the most widely used fused cast refractory brick. According to the ZrO2 content, it can be divided into 33#, 36# and 41#AZS.
Fused cast AZS magnesia carbon brick containing 33% ZrO2 is called 33# fused cast AZS; fused cast AZS containing 36% ZrO2 is called 36# fused cast AZS; fused cast AZS containing 41% ZrO2 is called 41# fused cast AZS.
Fused cast AZS is mainly composed of baddeleyite and corundum and their eutectic crystals. High viscosity glass phase is filled in the gaps of crystals. The crystals is directly precipitated monoblock stopper from the molten liquid and well developed. So, it has large crystal particles and stable crystal phase. Except the voids, it has compact structure and better density than the common sintered bricks. The pores are mainly closed pores and the crystals are intertwined each other, so it ladle slide gate has good mechanical properties and wear resistance. The impurities are difficult to invade the bricks. Therefore, this refractory brick has good corrosion resistance. besides, the transformation of ZrO2 at 900~1150℃ when heating or cooling may cause irregular deformation.
Fused cast AZS block can be used in areas in direct contact with molten metals and molten slags. It is the essential material used in the key areas that suffer from severe corrosion.

refractory company Henan Xinmi Changxing Refractory Material Co., Ltd. Located in Henan Province,China.ChangXing's product portfolio covers shaped products such as refractory materials,refractory brick, refractory castable,refractory nozzle, ceramic fiber, slide gate, etc; unshaped products including repair, construction and casting mixes and mortars.exported to more than 20 countries, such as Thailand, Indonesia, Pakistan, Saudi Arabia, South Africa, Turkey, Iran, Iraq and so on.
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Introduction of Changxing Refractory self-flow castable

2016年6月5日星期日

Chemical composition of fire clay bricks

Clay, High Alumina Insulating Bricks
The use of the bricks can reduce the heat capacity of kiln walls and promote the heat efficiency of kilns. The product is applicable for constructing industrial kilns and inner lining of kilns.
Fire clay brick is the refractory brick containing 30-46% SiO2. It is made of clinkers calcined from refractory clays as the oxidant and bond clay as a binder agent.
The main raw material is firebrick refractory clay. Clay is an earthy mineral. It can form plastic mud pie when mixed with water and maintain the shape after drying. It has rock-like hardness after fired at high temperature.
Additionally, the clay contains a certain amount of impurities such as quartz, mica, pyrite, feldspar and organic substances. The impurities, especially iron, can reduce the quality of clay refractory brick for sale and are harmful to the fire clay bricks.
Alkalis such as Na2O and K2O exist as mica. It can improve the sintering properties of clay and form dense products after sintered. It should be fewer than 2%.
The content of CaO is generally ladle refractory under 11.5% and distributed evenly. So, it will not affect the refractory properties of raw materials.
There is a certain amount of TiO2 in the bond clay. It exists as diamond. When it is less than 1%, it has no big effect on the quality of bond clay. In the chemical analysis, its content is not tested alone but counted in the content of A1203 + TiO2.
When the impurities in the clay exceed 6%, the refractories of clay will decease and cannot be used as the raw materials. The content of organic substances in the clay is fluctuated greatly, up to 5%.

refractory company Henan Xinmi Changxing Refractory Material Co., Ltd. Located in Henan Province,China.ChangXing's product portfolio covers shaped products such as refractory materials,refractory brick, refractory castable,refractory nozzle, ceramic fiber, slide gate, etc; unshaped products including repair, construction and casting mixes and mortars.exported to more than 20 countries, such as Thailand, Indonesia, Pakistan, Saudi Arabia, South Africa, Turkey, Iran, Iraq and so on.

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2016年6月2日星期四

The Composition and Properties of Magnesia Brick

Magnesia Alumina Carbon Brick, Alumina Magnesia Carbon Brick
Alumina Magnesia Carbon Bricks is made from high quality bauxite, corundum and fused magnesia. It is formulated with very high purity alumina and magnesia.
Magnesia refractory brick is a basic refractory product with periclase as its main mineral phase. It contains not less than 91% MgO and not less than 3.0% CaO.
Magnesia brick is composed of 80-90% periclase and 8%-20% other mineral phase including magnesium ferrite (MgO·Fe2O3), forsterite (2MgO · SiO2) and Calcium and magnesium refractory brick for sale olive stone (CaO·MgO·SiO2).Silicate glass contains about 3-5% magnesium, calcium and iron. These silicates may contain tricalcium silicate (3CaO · SiO2), magnesium rhodonite (3CaO · MgO · 2SiO2), calcium and magnesium olivine and forsterite, dicalcium silicate (2CaO · SiO2).
Magnesia brick has good thermal conductivity, good thermal expansion, good corrosion resistance to alkali molten slags and bad corrosion resistance to acid molten slags. Due to the low-melting silicate cements surrounded periclase, the beginning point of the softening temperature under load is not too high, but the collapse temperature is close to the beginning point. Its refractoriness is over 2000℃, but it does not make sense in the actual refractory castable use. Bad thermal shock stability is one of the main reasons for the destruction.
In the storage and transport, special attention should be paid to moisture-proof to avoid burst after affected with damp.

refractory company Henan Xinmi Changxing Refractory Material Co., Ltd. Located in Henan Province,China.ChangXing's product portfolio covers shaped products such as refractory materials,refractory brick, refractory castable,refractories nozzle, ceramic fiber, slide gate, etc; unshaped products including repair, construction and casting mixes and mortars.exported to more than 20 countries, such as Thailand, Indonesia, Pakistan, Saudi Arabia, South Africa, Turkey, Iran, Iraq and so on.

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Formation of smelting furnace slag layer

The Matrix Of Refractory Materials

Bottom Frame &Skid Platform Brick for Heating Furnace

Bottom Frame &Skid Platform Brick for Heating Furnace

The matrix of firebrick refractory refers to the substances present in the gaps of large crystals or aggregates.

Matrix has a decisive impact insulating castable on the properties of refractory products. During the use, the samage of refractories always starts from the matrix. Changing the matrix of refractories is an effective way to improve the properties of products.

Most refractory materials, refractory material according to the main crystal phase and matrix, can be divided into two types: refractories containing crystal phases and glass phase and refractories only containing crystals. The former includes fireclay brick, alumina brick silica brick, etc.. The latter includes magnesia brick, magnesia chrome brick, etc..

These products are fired at high temperature and contain a certain amount of liquid phase. refractory brick The liquid will not form glass phase when cooled but the crystalline matrix which is bonded together with the main crystal phase. The matrix crystal phases are different from the main crystal phase.

Henan Xinmi Changxing Refractory Material Co., Ltd. Located in Henan Province,China.ChangXing's product portfolio covers shaped products such as refractory materials,refractory brick, refractory castable,refractory nozzle, ceramic fiber, slide gate, etc; unshaped products including repair, construction and casting mixes and mortars.exported to more than 20 countries, such as Thailand, Indonesia, Pakistan, Saudi Arabia, South Africa, Turkey, Iran, Iraq and so on.

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2016年6月1日星期三

Refractories for cement industry

Calcium Silicate Pipe
calcium silicate product is used in industries including steel plants, cement clinker kiln, heat and power stations, foundries both ferrous and non-ferrous, cement producers, Aleris , ceramics, coke plants, incinerators, renewable energy, chemical works, sugar refineries and petrochemical industry. It is sell well in the world and we won a lot of trust both at home and abroad .
Alkaline Refractories
Alkaline refractory material is available for high temperature calcination, also has superior chemical resistance property, which is a main refractory material for cement kiln to keep high production quality, high yield, low consumption and long-term safe operation. Currently main material for cement kilns include direct-bonded magnesia chrome brick, semi-direct bonded magnesia chrome brick, ordinary magnesia chrome brick , dolomite brick, zirconium and zirconium-free special magnesite brick, spinel brick and chemically bonded unburned magnesia chrome brick.
Bricks properties are listed as follows:

High alumina brickHigh alumina brick has high compressive high insulating brick strength, high refractoriness under load and good thermal shock resistance. Because of its low cost with high quality, it is widely used in varieties of cement kilns. When to be used in arch crown, calcined alumina brick is better. High alumina bricks suitable for cement kilns include phosphate bonded alumina brick, phosphate bonded high alumina wear-resistant brick, anti-stripping alumina brick, chemically bound (special) castable refractory material alumina brick and general alumina brick and so on.
Alkali Brick Series
Alkali brick has excellent alkali corrosion performance, under certain conditions, it will react with the alkali compound kiln materials and kiln gas, rapidl. yclay insulating bricks forming enclosed type dense protective enamel layer on the turn, preventing the continuing internal mixing and bricks "base crack ", which is a indispensable kiln lining material in NSP kiln. This series bricks include ordinary alkali-resistant brick, high-strength alkali-resistant brick, insulation alkali-resistant brick and arch type alkali-resistant brick.
Series refractory castables
Refractory castables can be produced with simple production process, which is flexible and convenient to be used in the cement kiln system. It has become increasingly common to be applied in the complex structure of cement kiln preheater system. Refractory castables suitable for cement kiln mainly include corundum castable, high alumina castable, alkali-resistant castables and light weight castable.

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Molding methods of refractories and widely used refractories

Assembled Bricks for Blast Tuyere
Good abrasion resistance, good thermal shock stability, high temperature strength, good erosion resistance.It is widely used in Blast furnace tuyere, the circumference of the tube outlet, mixed air entrance, flue gas pipeline, turning tube etc..
There are many refractory material molding methods, such as common molding method, vibration extrusion method, extrusion method, pounding method and so on.
At present, when it comes to the production of firebrick refractory  materials, the most frequent way of molding refractory material is machine pressure molding method which is a way using brick molding machine and mold to compress the clay material into body. because the clay contains 5% water it is called semi-dry molding method. Machine molding is with compact structure, high strength, narrow drying and firing way, and size is also easy to control.castable  It can be divided into the single side pressure, and double sides pressure which can reduce the phenomenon of layer density.
refractory company The common refractory material are AZS brick, corundum brick, magnesite chrome brick, directly silica carbide, silicon carborundum brick, nitrides, silicides, sulfide, boride, carbide and other non oxide refractories materials; Calcium oxide, chromium oxide, aluminum oxide, magnesium oxide and so on..

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