With the rapid advance of industrialization, brought rapid development of cement, glass, chemicals, metallurgy and other high-temperature industrial, China's refractory material industry has entered a rapid development stage. At the same time, people are concerned about not only the right choice according to the specific working conditions suitable high-temperature furnace
Refractory, and further explore what kind of refractory material can only guarantee the life of the furnace and can reduce costs.
Hot work departments are required to have resistance to high temperature refractory heat load performance, but due to different job sectors, even in different parts of the same kiln, the working conditions are not the same. Following is a brief introduction to the following:
A technically meet the requirements of working conditions: the selection of refractory materials, must take into account the working conditions in various parts of the furnace, such as magnesia carbon bricks properties
furnace temperature level, changes in circumstances, the nature of the slag, and the situation was slag and molten metal baking mechanical friction or erosion. For example build lid, in addition to resistance
Outside temperature, but also has good thermal stability, otherwise, due to the frequent opening and closing the lid, can lead to the destruction of bricks, slag and against the requirement is secondary. On the contrary, in the vicinity of the slag line refractory company slag resistance must meet the requirements. All in all, the choice of suitable refractory
.
(A) I produced the high-temperature furnace refractories are the following:
1. zirconia zirconia brick products are the company fused zirconia sand as raw material, with a special high-temperature sintering. Zirconia brick has a high temperature (the highest temperature ≥2500 ℃), acid erosion, thermal shock resistance and other characteristics, widely used in military, scientific research
, Ultra-high temperature Ladle Backing Layer Castables metal smelting furnace, laser crystal, quartz glass, electronics and other industries and iron and steel casting and other occasions. Examples of key parts of the glass furnace AZS chrome material, medium-sized cement kiln cooling zone, the transition zone using zirconium Refractory like.
2. products corundum brick corundum pure white fused corundum, mullite, chromium oxide and other raw materials, sintered after molding, high temperature. Products with compact structure, high strength, high temperature (≥1790 ℃), good thermal shock resistance, acid and alkaline gases erosion,
From H2, CO and other reducing gas effect. High purity alumina bricks are widely used in petrochemical and other industries of oil or gas gasification furnace, high temperature furnace carbon black reactor ethylene gas furnace, ammonia decomposition furnace, chemical industry, refractory materials and ceramic industries; chromium corundum brick applied petrochemical industry, coal water
High temperature furnace lining pulp and petroleum coke gasifier backing, oil or gasifier working lining, carbon black reactor lining in the chemical industry, refractory industry; mullite corundum brick is widely used in carbon black reactors, refractories, ceramics, electronics industry, high-temperature furnace lining.
3. alumina article is a hollow ball of alumina brick alumina hollow ball, corundum powder, calcined powder as raw materials, homogenized, molding, high temperature sintering. Products with high temperature, acid erosion, low thermal conductivity, good insulation properties, low bulk density and other characteristics, the main
To be used for ceramics, porcelain, grinding wheels, refractories and other various high-temperature industrial furnace lining and insulation lining work.
(B), in short, regardless of which refractory Indexes in terms of high-temperature furnace must consider the following points:
1. The effect of changes in resistance and high-temperature vacuum work atmosphere, non-volatile, no damage. It requires a material having a low vapor pressure and high chemical stability.
2. The high-temperature heat resistance combined effect of heavy load and do not lose strength, creep and collapse. It requires a material having a relatively high temperature strength and high temperature hot strength, high load softening temperature, high creep resistance.
3. flame resistance and charge, feed dust erosion, impact and wear, surface loss. Require materials with a very high compactness and normal temperature, high temperature wear resistance.
4. resistance to high-temperature thermal load is applied, does not soften, not melted. Refractories requires a very high refractoriness.
5. resistance to sudden temperature changes or impact of uneven heating, no cracking, no peeling. Require materials with good thermal shock resistance.
6. resistance to molten metal, dust and gas chemical attack, not bad, not pitting. It requires a material having good slag resistance.
7. resistance to high-temperature thermal load is applied, the volume does not shrink and is just uniform expansion. Require materials with high volume stability, residual contraction and expansion remains to be small, no crystal transition and severe volume effect.
In addition, in order to ensure the overall quality of the refractory masonry block structure or a liner. Slag resistance and air tightness and ease of construction, also called material neat appearance, accurate size, to ensure a certain degree of tolerance, and do not allow to eliminate the defects. In order to withstand handling
The shock and mechanical vibration and squeeze may occur, requiring the material must have a relatively high temperature strength. For some special requirements of the Department, and sometimes also consider its thermal and electrical conductivity.
Second, economically justified: the selection of refractory materials, in addition to considering the technical requirements, but also need to pay attention refractory cost and supply issues. There are many refractories, although performance is good, but expensive, use is restricted. Usually easy to damage the furnace refractory material part
To high quality material, the material can be low, they do not noble material. Select the most suitable refractory material can reduce the damaging effects of high temperature flames and slag on the lining, but also regular maintenance furnace, timely repair work. In addition, reasonable thermal system, furnace temperature control, to avoid furnace
Temperature is too high hazard and shorten the life of the furnace;
It should be noted that although the above is described as the basis for evaluation of the quality of the refractory, but without any kind of refractory material able to fully meet all the above requirements. When selecting the evaluation or refractory, we must highlight the features and conditions of use of the material to adapt the best use
. While taking into account economic accounting.
As we engage in the production of refractories enterprises, but also includes an upstream raw materials and downstream producers of cement, glass, chemicals, metallurgy and other business users, refractory enterprises should take the initiative to strengthen cooperation with upstream and downstream enterprises and research institutions, and actively promote compliance with the actual production demand
The high cost of refractory application and promotion, give full play to the positive role of a benefit to users of refractories and related industries of energy conservation, energy.
Another refractory article:
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2016年8月29日星期一
2016年8月25日星期四
Ladle slide gate damage theory and meaning of conjunction
Ladle slide gate plate mainly contains two types, alumina carbon and alumina zirconium carbon. With steel production increasing and steel quality improving, firebrick refractory sale calcium treatment process is applied, therefore, calcium content in the melton steel increased. Using alumina carbon and alumina zirconium carbon slide gate plate when casting steel, SiO2 and Al2O3 in the slide gate plate would mixed with [Ca], [CaO] in the melton steel or slag and get into low-melting ladle slide gate point materials and feldspar, which would cause damage of slide gate plate. This type low-melting point materials would be easy to crushed down by erosion, new low-melting point material would re-appear. This progress would cause the erosion heavier, in which way the slide gate plate would be damaged gradually.
Conjunction of slide gate plate can reduce the ceramic fiber felt number of turnover ladle, low down ladle serves and turnover pressure. In addition, slide gate plate conjunction can low down labor working, improve ladle lining temperature, thus low down casting temperature and bring a number of benefit for production and reducing cost.
From Year 2008, our refractory material factory succeed to develop double conjunction and from Year 2010, triple conjunction is developed. With the triple slide got into the normal production, on-site production, reduce labor intensity, the effect of reducing the cost of generation is very obvious.
Generality High Alumina Brick &Clay Brick,High Alumina EPS insulating Firebrick,Low Creep High Alumina Brick are mainly products in Changxing Refractory
Generality High Alumina Brick &Clay Brick
Changxing Refractory's High Alumina Bricks and Fireclay range is available in different varieties/shapes as per the specifications given by the clients. We provide High Alumina Bricks that are highly resistant and durable without causing any environmental hazards maintaining High standards are made from a variety of raw materials having different properties. Shapes of the High Alumina Bricks are made as per the drawings and measurements provided by the clients and only high grade fireclay and raw materials are used in their manufacturing.It is used in lining furnace kilns, fireboxes and fireplaces. Its primary purpose is to withstand high temperature and also to retain the heat for greater energy efficiency. We offer wide range of low, medium & high alumina refractory firebricks. High alumina brick have very good ability of anti-acidity, anti-metal fluid corrode and anti-oxidation.
High alumina brick have very good ability of anti-acidity, anti-metal fluid corrode and anti-oxidation.
High Alumina EPS insulating Firebrick
This series of products are sintered mainly with supper-fine bauxite chamotte, and proper additive by a method of EPS ignition loss, Their main advantages include high intensity, low thermal conductivity, excellent thermal stability, very small reheat linear change, outstands erosion and corrosion resistance etc.
1. High strength
2. Optimum performance
3. Dimensional stability
4. Low thermal conductivity
They are an ideal kind of energy-conserning products which can be widely used as lining or insulating layers of various industrial furnaces and kilns in metallurgical industry, machine building industry, ceramic industry, chemical industry, etc. Recommended service temperature: Less than 1400C.
Clients can avail from us a wide variety of Fire Bricks, which is widely demanded for their high strength. The offered bricks are manufactured using high-grade material and advanced techniques, thus complying with the international industry standards. Our array of bricks is extensively used as lining in fireplaces, fireboxes, furnaces and kilns.
Moreover, clients appreciate our products for their following quality attributes.
Low Creep High Alumina Brick
The regenerative capacity of large, small creep rate.
Hot air furnace supporting small and medium blast furnace.
2016年8月8日星期一
Fused Cast AZS Block and Glass Defects
Fused cast AZS block exudation is thought as the leading cause of knot and cord defects. Fused cast AZS exudation is only a short-term source of glass defects. Fused cast AZS corrosion is a more potent and long-term source of defects. Glass melt contact refractory corrosion castable refractory material can lessen with time due to boundary layer formation and the effect of external cooling at the metal line.
The interaction of glass melts and refractories in glass furnaces has a large impact on the resulting glass quality. The mostly applied type of refractory in the glass industry, in direct contact with the glass melt, is fused cast AZS. Due to the interaction of the glass melt clay insulating bricks with fused cast AZS, glass defects like stones, knots and bubbles can be generated.
Fused cast AZS block has no open porosity but there are some closed voids and pores which arise from the manufacturing process. These pores are filled with gases. The gases in these pores refractory fiber board have an air like composition, with nitrogen and oxygen as main components and some carbon dioxide. When fused cast AZS is in contact with glass, it reacts with the glass melt and slowly dissolves in this melt. The closed pores will be opened and then release their gas content, forming bubbles.
Impurities, which can oxidize, are for example elemental carbon originating from graphite electrodes of the fused casting operation, sulfur or zirconium carbide originating from raw materials of the AZS. The dissociation/oxidation of nitrides/oxynitrides, produced by reactions with the graphite electrodes during melting of the AZS, could give nitrogen insulating castable gas.
The generation of a knot is due to one or more forces, which drive the fused cast AZS glass phase towards the refractory surface and into the bulk of the glass melt. Those forces can be caused by gravity, thermal expansion of zirconia and gas formation.
Glass defects are typically unavoidable, but their occurrence must be minimized during the production of high-quality glasses. Some alternatives, such as fused cast AZS with modified chemistry and glassy phase and alpha-beta fused cast alumina block are used to replace fused cast AZS to reduce the glass defects and improve the glass quality.
When fused cast AZS block is brought into contact with a glass melt, an electrical potential is generated between the refractory and the glass melt because generally no thermodynamic equilibrium exists between these materials. The electromotive force (emf) generated between glass melt and refractory interior can cause the formation of oxygen bubbles.
Henan Xinmi Changxing Refractory Material Co., Ltd. Located in Henan Province,China.ChangXing's product portfolio covers shaped products such as refractory material,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.
The interaction of glass melts and refractories in glass furnaces has a large impact on the resulting glass quality. The mostly applied type of refractory in the glass industry, in direct contact with the glass melt, is fused cast AZS. Due to the interaction of the glass melt clay insulating bricks with fused cast AZS, glass defects like stones, knots and bubbles can be generated.
Fused cast AZS block has no open porosity but there are some closed voids and pores which arise from the manufacturing process. These pores are filled with gases. The gases in these pores refractory fiber board have an air like composition, with nitrogen and oxygen as main components and some carbon dioxide. When fused cast AZS is in contact with glass, it reacts with the glass melt and slowly dissolves in this melt. The closed pores will be opened and then release their gas content, forming bubbles.
Impurities, which can oxidize, are for example elemental carbon originating from graphite electrodes of the fused casting operation, sulfur or zirconium carbide originating from raw materials of the AZS. The dissociation/oxidation of nitrides/oxynitrides, produced by reactions with the graphite electrodes during melting of the AZS, could give nitrogen insulating castable gas.
The generation of a knot is due to one or more forces, which drive the fused cast AZS glass phase towards the refractory surface and into the bulk of the glass melt. Those forces can be caused by gravity, thermal expansion of zirconia and gas formation.
Glass defects are typically unavoidable, but their occurrence must be minimized during the production of high-quality glasses. Some alternatives, such as fused cast AZS with modified chemistry and glassy phase and alpha-beta fused cast alumina block are used to replace fused cast AZS to reduce the glass defects and improve the glass quality.
When fused cast AZS block is brought into contact with a glass melt, an electrical potential is generated between the refractory and the glass melt because generally no thermodynamic equilibrium exists between these materials. The electromotive force (emf) generated between glass melt and refractory interior can cause the formation of oxygen bubbles.
Henan Xinmi Changxing Refractory Material Co., Ltd. Located in Henan Province,China.ChangXing's product portfolio covers shaped products such as refractory material,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.
What Is Fused Cast Alumina Block
Clay, High Alumina insulating bricks First melt the raw materials in an electric arc furnace. When the material has become molten and its chemical and physical characteristics have been adjusted to the desired condition, pour the ladle slide gate molten material into a mold. Then the cast product is processed with machines into the final product.
Fused cast alumina block is made of pure alumina powder(>95%) and a small amount of additions (soda sand and quartz sand). There are commercially 3 types of fused cast alumina blocks: Beta fused ceramic fiber felt cast alumina block, Alpha-beta Fused cast Alumina Block and Alpha fused cast alumina block.
Beta fused cast alumina block comprises of a majority of beta alumina crystals and a slight portion of alpha alumina crystals in compact structure. Moreover, the intersected texture of large beta-alumina ensures great dimensional stability and great resistance against spalling. Its property of base saturation enables a higher resistance to alkali vapor, thus it has excellent thermal shock resistance and does not form molten droplets. It is the best material for molter crown, port crown,feeder channel,ect. Its neutrality against soda vapors makes it the best choice for the downstream part of superstructures in demanding applications.
Alpha fused cast alumina block is ladle castable an ideal product for the lower temperature zones of the glass melting furnaces due to its high density, superior corrosion resistance and low blister potential. It is also an ideal material for Metallurgical Titanium Furnace because the superior thermal stability.
Alpha-beta Fused cast Alumina Block is formed by the compact structure of alpha alumina and beta alumina crystals in a most ideal proportion which is approximately 50% and 50% respectively,where intertwined crystals of both materials result in a very dense structure. Below 1350 ℃, it has excellent corrosion resistance against molten glass and great performance against contamination to molten glass, thus it is very suitable for paving blocks and fore-hearth channel blocks. When in contact with molten glass, it barely produces any blistering or stones. So, it may be widely used in working tank, feeder channels, superstructures and lipstone, etc. In soda-lime container furnaces, it is installed in the Alcove and channel areas, as alternative to fused cast AZS for Alcoves and as alternative to AZS fused-cast, zirmul, sinter-alumina and other sinter refractories for channels.
Henan Xinmi Changxing Refractory Material Co., Ltd. high insulating brick 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.
Fused cast alumina block is made of pure alumina powder(>95%) and a small amount of additions (soda sand and quartz sand). There are commercially 3 types of fused cast alumina blocks: Beta fused ceramic fiber felt cast alumina block, Alpha-beta Fused cast Alumina Block and Alpha fused cast alumina block.
Beta fused cast alumina block comprises of a majority of beta alumina crystals and a slight portion of alpha alumina crystals in compact structure. Moreover, the intersected texture of large beta-alumina ensures great dimensional stability and great resistance against spalling. Its property of base saturation enables a higher resistance to alkali vapor, thus it has excellent thermal shock resistance and does not form molten droplets. It is the best material for molter crown, port crown,feeder channel,ect. Its neutrality against soda vapors makes it the best choice for the downstream part of superstructures in demanding applications.
Alpha fused cast alumina block is ladle castable an ideal product for the lower temperature zones of the glass melting furnaces due to its high density, superior corrosion resistance and low blister potential. It is also an ideal material for Metallurgical Titanium Furnace because the superior thermal stability.
Alpha-beta Fused cast Alumina Block is formed by the compact structure of alpha alumina and beta alumina crystals in a most ideal proportion which is approximately 50% and 50% respectively,where intertwined crystals of both materials result in a very dense structure. Below 1350 ℃, it has excellent corrosion resistance against molten glass and great performance against contamination to molten glass, thus it is very suitable for paving blocks and fore-hearth channel blocks. When in contact with molten glass, it barely produces any blistering or stones. So, it may be widely used in working tank, feeder channels, superstructures and lipstone, etc. In soda-lime container furnaces, it is installed in the Alcove and channel areas, as alternative to fused cast AZS for Alcoves and as alternative to AZS fused-cast, zirmul, sinter-alumina and other sinter refractories for channels.
Henan Xinmi Changxing Refractory Material Co., Ltd. high insulating brick 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8月4日星期四
The reasons that the damage of ladle upper nozzle and its reventive measures
 |
| Ladle nozzle shows features of excellent thermal shock resistance, good excellent corrosion and erosion resistance, strong cracking resistance, long service life etc. |
1. The reasons that the damage of ladle upper nozzle
1) Under the scouring and erosion of liquid steel and steel slag, the slag erosion will occur under wrong operation process.
2) Mechanical damage during installation process.
1) Under the scouring and erosion of liquid steel and steel slag, the slag erosion will occur under wrong operation process.
2) Mechanical damage during installation process.
2. To prevent the damages of refractory material sliding gate nozzle system, measures should be taken as below:
1) Use better raw material with high corrosion and erosion resistantance to make the upper nozzle, such as the corundum quality upper nozzle.
2) Choose to use products with high mechanical strength.
3) Note the operations of ladle casting process, to avoid the discharge of slag.
1) Use better raw material with high corrosion and erosion resistantance to make the upper nozzle, such as the corundum quality upper nozzle.
2) Choose to use products with high mechanical strength.
3) Note the operations of ladle casting process, to avoid the discharge of slag.
Article sourse：
The application and working principle of Sliding Nozzle
Nowadays sliding nozzle systerm is becoming more and more important in the process of melting and be an necessary part for melting. It is the control device of molten steel in casting process, which can precisely adjust the water flow from ladle to tundish, to make the flowing and flowing out of the molten steel can reach a balance, so that the continuous casting operation is easier to control.Because of its good controllability, the sliding gate system can improve the efficiency of steel making and has been developed rapidly. At present, the sliding gate system is widely used in ladle and tundish.
Generally, the sliding nozzle is composed of a driving device, a mechanical part and a refractory material part (i.e. upper and lower slide plate, nozzle). The working principle of the sliding gate is to slide the upper and lower sliding plate brick through the sliding mechanism, thereby driving the opening and closing of the flow steel hole to adjust the flow rate of the molten steel.
As the refractory material and mechanical component of the sliding gate system,in order to obtain a longer service life and stable operating conditions,sliding gate is requested with excellent properties.
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