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Why do Corundum Mullite Bricks Lose Edges and Corners During the Grinding and Laying Process?

2024-05-10 by globalrefractory

At present, corundum mullite bricks are one of the main products of blast furnace ceramic cups. Corundum-mullite bricks have some drawbacks in terms of performance. The main manifestation is that the product has serious missing edges and corners during the grinding and masonry process, which affects the masonry quality of the product. Corundum mullite bricks are only qualified when the quality qualification rate of corundum mullite bricks is guaranteed to increase by 2%. Rongsheng refractory material manufacturer‘s strict quality of corundum mullite bricks acceptance has won the recognition of customers. And promoting the sales of our refractory products to more than 100 countries around the world.

Rongsheng Corundum Mullite Brick for Sale

Analysis of the Causes of Missing Edges and Corners of Corundum Mullite Bricks During Grinding and Laying Process

Corundum mullite bricks have serious missing edges and corners during the grinding and laying process. Rongsheng Refractory Materials Manufacturer analyzes the reasons and summarizes them as follows.

Hardness. Hardness is generally considered an important indicator of a material’s wear resistance. The harder the material, the better its wear resistance, but in the case of large impact wear, the impact of hardness is not necessarily very large. Refractory bricks are heterogeneous and the hardness of each part may be different. For refractory bricks containing corundum and silicon carbide, if the bonding strength is sufficient, these high-hardness materials can still resist the wear of the refractory bricks after the low-hardness and easy-to-wear materials wear away.
Crystal structure and crystal solubility. Materials with a specific crystal structure have better wear resistance. For example, cobalt with a close-packed hexagonal structure has a small friction coefficient and is wear-resistant. Metallurgically speaking, metals with poor mutual solubility also have good wear resistance.
Strength. Refractory bricks will encounter a lot of impact wear during use. Therefore, high-strength refractory bricks have strong wear resistance.
Volume density. Refractory bricks with high volume density and low apparent porosity have strong wear resistance.
Temperature. Temperature affects the hardness, solubility and reactivity of materials, thus indirectly affecting the wear resistance of refractory bricks. Generally, as the temperature increases, the solubility and reactivity increase. Refractory bricks are used at high temperatures, and their wear resistance at high temperatures is very important.
Atmosphere. Similar to the effect of temperature, the atmosphere affects the mutual solubility and reactivity between materials, thereby affecting their wear resistance.

RS Corundum Mullite Bricks — Corundum Mullite Bricks Directly from RS Factory

Technical key and project implementation content to improve the performance of corundum-mullite bricks

The product formula system is modified in a targeted manner based on the above factors. In the production process of this product, the density of the bricks is increased through reasonable particle gradation and the selection and use of high-quality aggregates. Optimize and increase the firing temperature to improve the physical and chemical properties and wear resistance of the product. Ensure the quality of the later grinding and masonry processing of the product, thereby ensuring the improvement of the quality of the pre-masonry of the product.

1) Use high-quality raw materials. Better quality alumina grade raw materials and brown corundum raw materials are used as aggregates. It ensures the high hardness of the material and increases the toughness of the refractory material without increasing the cost.

2) Increase the proportion of brown corundum fine powder and alumina fine powder in the matrix fine powder. Reduce the porosity of the product after firing and increase the density of the product.

3) Change the traditional product stacking method and add air inlets for kiln car stacking to make the firing temperature more uniform.

4) Increase the product sintering temperature so that the product is fully sintered and the internal materials are fully integrated and mutually soluble.

Implementation plan to improve the performance of corundum mullite bricks

⑴ Combined with the performance requirements of the product, select raw materials with higher density and hardness. It was finally decided to use a raw material combination of brown corundum and bauxite. Brown corundum acts as a skeleton in terms of hardness, providing high strength to the product. Bauxite is slightly inferior to brown corundum in terms of hardness, but it is tough and can wrap brown corundum at a slightly lower firing temperature. Use together to meet product performance and economic indicators.

⑵ Combined with the original formula structure, a small amount of bauxite is combined with brown corundum and then supplemented with mullite raw materials and alumina powder. The bricks are formed using high pressure to increase the density of the bricks and form a highly polymerized body. Change the traditional kiln coding method, increase the hand seam width, improve the temperature homogenization performance of the kiln car, and determine the appropriate firing temperature. The product can achieve the effect of mutual dissolution of raw materials, tight combination, and tiny pores inside the product.

Customized White Corundum Mullite Bricks from Rongsheng Manufacturer

Technical summary

In the first stage, the raw materials entering the factory are optimized. After inspecting various brown corundum raw materials and bauxite raw materials, and after research and discussion by the project team’s technical staff, it was finally decided to use Dengfeng’s brown corundum and Shanxi bauxite.

In the second stage, the formula ratio of the corundum-mullite product was further optimized, and the stacking method and firing temperature were determined through multiple experiments. The principle of close particle packing is used to adjust the proportion of aggregate and powder. At the same time, the ratio of brown corundum particles and alumina particles is adjusted in various proportions. It was finally decided to use a ratio of 2:1 to achieve a tight packing effect and also play a role in wrapping and soluble in each other. In the matrix fine powder, 2a% of alumina powder is added to increase the aluminum content and at the same time reduce pores. A 630-ton press is used for heavy-duty molding to increase the density of the bricks from 3.1 to 3.15. Relax the hand seams of kiln bricks and increase the width by 5mm. The kiln car fire channel is added to increase the firing temperature of the product by 40°C, so that the product is fully melted and the internal structure is dense.

In the third stage, multi-batch deployment plans are trial-produced, and a stable production plan is finally obtained.

Improved Performance of Corundum Mullite Bricks

Corundum mullite bricks use brown corundum combined with bauxite to enhance the wear resistance of the product. However, it has a certain impact on the high-temperature load softening temperature of the product, and the proportion of alumina is not easy to increase.

The amount of aluminum oxide powder added is controlled at 2a%, which is sufficient. Excessive alumina powder affects the firing temperature and also reduces the brick density.

In the matrix fine powder, it is advisable to reduce the addition of bauxite raw materials. The addition ratio can be reduced to 1a% to enhance the hardness of the matrix.

Rongsheng Refractory Materials Manufacturer is a powerful manufacturer of refractory materials production and sales. Our corundum mullite brick products have stable and reliable performance. Strict factory inspection. It extends the service life of the refractory lining of the customer’s industrial furnace and ensures the economic benefits of the customer’s production. Contact us to get free samples and quotes.

Zircon Bricks for Glass Kiln Lining

2024-05-04 by globalrefractory

Why use zircon bricks for the construction of glass kilns? In the glass melting furnace, the molten glass liquid and the flame-flying material will cause certain erosion and damage to the zircon refractory bricks. refractory lining of the kiln, which in turn affects the service life of the glass-melting furnace. In addition, it is necessary to reduce the pollution of the molten glass.

Zircon Bricks for the Construction of Glass Kiln

From the performance indexes of representative zircon bricks for glass kilns at home and abroad, zircon bricks are more wear-resistant, more resistant to corrosion, and can reduce the pollution of molten glass. Zircon brick with such properties for glass kiln:1. High refractoriness and high softening temperature.2. anti-slag liquid erosion ability, strong acid resistance.3. High compressive strength.4. Good thermal shock resistance. The zircon brick is used for the working layer of the glass kiln wall, and its density is high, and it is strong against the glass liquid as the working layer of the pool wall. Therefore, the choice of zircon brick refractories for glass furnaces can extend the life of glass furnaces and improve the quality of glass. The zircon bricks used in the glass kiln are made of zircon as the main raw material, added with a binder and an additive, and are equipped in proportion, stirred, kneaded, formed, dried, and then fired at a high temperature. Zircon bricks with the zircon castables can work better in the glass kiln.

Zircon Bricks - Rongsheng Refractory Bricks — Zircon Bricks for Glass Kiln

What is the price of zircon bricks for a glass kiln? The price of zircon bricks on the market is currently not fixed. The actual price of zircon bricks for a glass kiln needs to consult the manufacturer, combined with the actual situation of the glass kiln, in order to get the most satisfactory products and quotations.

Performance of Sintered Zircon Brick for Glass Kilns

High temperature-resistant and corrosion-resistant zircon bricks are made of zircon as the main raw material, added with binders and additives, equipped in proportion, and fired at high temperature after mixing, mixing, molding, and drying. Also called sintered zircon brick.

Zircon bricks are divided into the high-density type and dense type according to production technology and physical and chemical indicators. RS Company Zircon Refractory Bricks for Sale, Sintered Zircon Brick for Glass Kilns, and Sintered Zircon Bricks for Glass Kilns are mainly used for the working layer of the wall of the glass kiln. Its density is high, and as a working layer of the pool wall, it has a strong ability to resist the corrosion of glass liquid. In recent years, the world’s glass industry melting furnaces have developed in the direction of large-scale and energy-saving.

Dense Zircon Brick with High Density and Low Porosity for Glass Kiln

The dense zircon brick with high density and low porosity is a special type suitable for the lining of the glass furnace melting pool for glass fiber melting. Generally, the production method of whole powder material, casting molding, and high-temperature firing are adopted. Performance of Dense Zircon Brick for Glass Kilns. 1. High refractoriness and high softening temperature. 2. Strong resistance to slag liquid erosion and strong acid resistance. 3. High compressive strength. 4. Good thermal shock resistance. Zircon Brick for Glass KilnsMethod for Improving Performance of Sintered Zircon Brick for Glass KilnsZircon bricks have high refractoriness and load softening point, low thermal expansion rate, and are not easily dissolved by chemical attack of molten slag. However its resistance to penetration (infiltration resistance) is poor, and the slag can penetrate into the brick through the pores. At the same time, it reacts with the decomposed zircon particles to form a metamorphic layer and collapse the brick structure. To improve the use effect of zircon bricks, the permeability of its slag must be reduced.

The improvement method is as follows: ① By adjusting the particle composition and changing the molding method, products with low porosity and air permeability are produced. However, products made by this method will inevitably reduce their thermal shock stability.②Add some additives to the bricks to increase the viscosity of the bricks and molten slag. High-purity zircon raw materials, a small number of high-efficiency additives, and suitable firing temperatures are the key factors for making high-density zircon bricks. The introduction of additives can not only ensure that the product can be fully sintered at a temperature far lower than the decomposition temperature of zircon but also reduce the reactivity, wettability, and permeability between the molten glass and the brick to varying degrees. Clay combined with zircon bricks, the type and amount of clay used greatly affect the properties of the bricks. The addition of clay will reduce the refractoriness of the product because Al2O3 has a solvent effect on zircon. In the ZrO2-Al2O3-SiO2 ternary system, when the composition is ZrSiO4 15%, Al2O3 15%, and SiO2 70%, a eutectic liquid phase is formed, and its melting point is 1610℃.

As the firing temperature increases, the apparent porosity of the clay-combined zirconite brick decreases, the air permeability increases, the number of coarse pores increases, the compressive strength and high-temperature flexural strength increase, and the corrosion resistance of the product increases. At the same time, the thickness of the impregnated layer increases. When the binding clay is not added, the proportion of the fine zircon powder is changed, and the test result of sintering at 1500 ℃ shows. As the amount of zircon fine powder increases, the air permeability decreases, the number of fine pores increases, and the corrosion resistance of the product becomes better. When the amount of zircon fine powder is 60%, the thickness of the impregnated layer is the thinnest. It can be seen from the above analysis that to adjust the corrosion resistance of the product, reduce the air permeability, improve the pore distribution, and obtain a zircon product with strong resistance to penetration. In the process, it is necessary to consider adopting a suitable firing temperature, adding an appropriate amount of fine zircon powder, and using a small amount of bonding clay.

For more information about zircon bricks for glass kilns, you can send us an email or by WhatsApp: +86 185 3831 2977.

RS Kiln Lining Refractory Materials for Glass Kilns

2024-04-28 by globalrefractory

What are the Refractory Bricks for the Lining of the Glass Kilns? The lining of the glass kiln is subject to chemical erosion, mechanical erosion, and large temperature fluctuations, and the refractory materials used for the glass kiln lining are like…Contact RS Refractory Company for a Free Quote. Glass is mainly made by using silica sand and soda ash as raw materials through high-temperature melting. A Glass melting furnace is thermal equipment for melting glass, usually made of refractory bricks.

Fused AZS Refractory Bricks for Glass Furnaces

Refractory Materials for Glass Furnaces

Glass melting furnaces can be divided into two categories: pool kilns and crucible kilns. According to the operation mode, it is divided into continuous operation furnaces and intermittent operation furnaces. According to the heating method, it can be divided into the flame kiln and electric heating kiln. So, how should refractory bricks be used in glass kilns? Perhaps manufacturers of refractory materials for glass kilns will answer such questions for us. Refractory Bricks Used for Glass Kiln. Because refractory bricks are widely used, from low temperature to medium temperature to high temperature, it is a necessity for the construction of the lining structure of industrial kilns.

When we choose refractory materials, we must consider many aspects. How to choose our applicable refractory brick products. First, we need to see which type of brick we need. Refractory bricks have different brick types and different uses. Secondly, we must see which kind of furnace is used and then the quality of refractory bricks. When determining the demand, the quality of the refractory bricks meets the standard and then compares the prices. Selection of refractory bricks for glass kiln is the most common type of kiln used in the glass industry. It is made of refractory bricks. There are flame-type pool kilns and electric-heated pool kilns.

The crucible kiln is to put the glass batch materials into the crucible, and then put them in the kiln to heat them together and then pour them into glass products after the materials are melted. The characteristic of this kiln is that the molten glass does not directly contact the kiln lining and the crucible is generally made of high-alumina refractory bricks and clay refractory bricks. The damage to the lining of the glass melting furnace is mainly chemical erosion and has the effect of thermal stress. The degree and speed of chemical attack are closely related to the location of use, the temperature of the furnace, and the type of molten glass. Of course, the quality of the lining itself is also very important. When choosing refractory bricks for glass melting furnaces (https://www.hy-refractory.com/service/product_knowledge/glass-tank-furnace-refractories.html), consideration should be given to the type of furnace, the location of its use, and its damage mechanism, the type of melting glass, and the type of fuel.

Fused Zirconia Corundum Bricks for Glass Kilns

Fused Zirconia Corundum Bricks. Categories Refractory Bricks. WikiTags: Lining of the Glass Kilns, Refractory Bricks. At present, fused zirconia corundum bricks and corundum bricks are widely used at home and abroad at the wall and bottom of the glass kiln in contact with the molten glass. The lower layer of the melting pool is built with clay refractory bricks. What are the precautions when using clay refractory bricks in the glass kiln? Clay refractory bricks are commonly used refractory bricks in blast furnaces, hot blast stoves, heating furnaces, ceramics, and refractory brick firing kilns. In order to achieve the best results, we need to pay attention to the following matters when used in a glass furnace.

Large Fireclay Refractory Bricks for Glass Kiln

Large Fireclay Bricks for the Glass Kilns

Large Fireclay Bricks for the Glass Kilns. 1. Clay refractory bricks cannot bear weight or be compressed when used at high temperatures. Therefore, it can only be used on the lower part of the pool wall or at a lower temperature at the bottom of the pool. 2. The gap between refractory bricks is controlled within 1.5mm~2mm. 3. The inside of the kiln shell should be flat without unevenness, let alone tilted.4. When using refractory bricks, clean the dust and slag scraps on the inner wall of the kiln shell to avoid loosening. 5. Leave a little expansion joint between the refractory bricks. 6. Bond clay refractory bricks with special cement for refractory bricks. 7. The lining of important parts and parts with complex shapes should be pre-laid first. 8. The lock seam should be firm. When processing bricks, bricks should be finely processed with a brick cutter, and manual processing of bricks should not be used. The capped bricks in the rotary kiln and under the brick slabs should not be less than 70% of the original bricks. In flat joint bricks and curved bricks, it shall not be less than 1/2 of the original bricks. It must be locked with original bricks. The processing surface of the brick should not face the inner side of the furnace. 9. Clay refractory bricks must be stored in a dry warehouse. Having mastered the selection techniques and methods of these refractory brick materials for glass kilns, I believe you will easily find the refractory bricks for glass kilns that best suit your production needs. For more information, please stay tuned to this blog.

And also the Insulating Fire Bricks Used for Kiln Linings. Insulating Fire Bricks of different materials, when used for kiln linings, can increase the heat storage function of industrial kilns and reduce the loss of energy… Contact Rongsheng for Free Quote of Refractory Bricks Categories.

RS Kiln Lining Refractory Materials for Cement Kilns

2024-04-272024-04-20 by globalrefractory

RS Cement Kiln Lining Refractory Bricks for Sale. Commonly used refractory bricks in cement kilns include low-temperature and alkali-resistant bricks, and high-temperature and high-temperature Silicon Carbide Mullite Bricks. Cement Kiln Lining Refractory Bricks … For Free Quote at inquiry@global-refractory.com.

Alkaline Refractory Bricks for Cement Kilns

Why Use Alkaline Refractory Bricks for Precalcined Cement Kilns? During the calcination process of the pre-calcining kiln clinker, a large amount of melt (liquid phase) appears in the kiln material from the back end of the upper transition zone. Some ingredients in the kiln material are calcined in the melt-through of the raw maturation material until it is out of the kiln. Within this range, alkaline refractory bricks that withstand high temperatures can meet their process performance requirements. The masonry length of alkaline refractory bricks is about (6~10)D of the kiln diameter, which is also the most severely damaged part of the lining brick. The use of the lining brick in this part directly affects the operation rate of the kiln. Therefore, the technological progress product performance, and output status of basic refractory bricks are paid attention to by people.

Alkali Resistant Bricks for Rotary Kilns

Magnesia Chrome Bricks for Cement Kiln

At present, the alkaline refractory bricks used in the pre-calcining kiln are mainly spinel magnesia bricks that directly join magnesia-chrome bricks and magnesia-aluminum bricks. This article mainly introduces the direct bonding of magnesia-chrome bricks. Directly Bonded Magnesia-Chrome Brick, Brief Introduction of Directly Bonded Magnesia-Chrome Brick for Cement Kilns. Magnesia-chrome bricks appeared in the 1930s. At that time, the performance of silicate-combined magnesia-chrome bricks (common magnesia-chrome) was still relatively poor and was used in traditional rotary kilns. Beginning in the 1960s, there have been direct-joined magnesia chrome bricks (straight magnesia bricks) with better performance.

Due to the high-temperature resistance, melt erosion resistance, redox resistance, mechanical stress resistance, and excellent kiln hanging performance of straight magnesia bricks, after being put into use, it is widely used in the transition zone and firing zone of the preheater kiln. Become the mainstream. In the 1980s, the output and diameter of the pre-calcining kiln were further expanded. In addition, due to the rapid increase in crude oil prices, coal with high ash content and petroleum coke with high sulfur content gradually replaced fuel oil. The high content of alkali sulfur makes the straight magnesia bricks in the upper and lower transition zones of the kiln vulnerable to damage and shortens the service life.

As a result, magnesia-aluminum spinel bricks with strong alkali-sulfur corrosion resistance have been used in the upper and lower transition zones of some large-scale pre-calcining kilns. At this point, the dominance of magnesia bricks began to break. In the late 1980s, some industrialized countries further emphasized the problem of chromium pollution, that is, when magnesia-chrome bricks are used in cement kilns, Cr3+ is transformed into Cr6+ which is harmful to the environment and the human body. Industrialized countries have formulated a series of regulations on environmental protection, sanitation, and cement-related ingredients. Fully monitor the residual bricks of cement kiln magnesia-chrome bricks, the drainage of cement plants, and the chromium content of cement products. In the 1990s, some cement companies in industrialized countries used relatively cheap industrial waste as raw material fuel due to environmental protection needs. Increased the alkali sulfur’s erosion of kiln lining materials, and put forward more demanding requirements for alkali refractories.

To promote the further optimization of magnesia-chrome bricks, super-direct bonded magnesia-chrome bricks with better performance have appeared in the pre-calcining kilns with more severe working conditions. On the other hand, the process of chromium-free alkaline bricks is accelerated to further improve and improve technology. In the 21st century, chromium-free alkaline bricks have completely replaced magnesia-chrome bricks in some industrialized countries and have better performance than magnesia-chrome bricks. It is specifically reflected in the development trend of the further increase in the operation rate of the pre-calciner kiln and the further decrease in brick consumption. In my country, in 2014, the Ministry of Environmental Protection formulated the solid waste production cement pollution control standard, which specified the limit of the pollutant content in cement products, Cr6+, to be 0.05mg/L. Its value is close to that of industrialized countries. It can be said with certainty that the limit value will definitely become stricter over time.

Although restricted by environmental protection regulations, magnesia-chrome bricks are still used by some cement plants due to their excellent kiln-hanging properties and relatively low prices. They are the most consumed variety in cement production. But the general trend is to decline year by year. At present, some people of insight in my country’s cement industry have raised the issue of chromium pollution in some conferences and articles, which has attracted the attention of relevant leaders.At the same time, some design units have reduced or stopped using magnesia-chrome bricks in their drawings. Some large domestic cement groups and foreign-funded enterprises have partially or completely stopped using magnesia-chrome bricks. The above situation greatly reduces the usage of magnesia-chrome bricks. In addition, the fuel used in some areas contains high sulfur content, which intensifies the chemical erosion of magnesia-chrome bricks, forcing companies to reduce or stop using them.

As the country further strengthens the environmental protection of water resources and controls the chromium content in cement. The regulation on the limit value of hexavalent chromium in magnesia-chrome brick residual bricks will be strict with time. In the end, forcing magnesia-chrome bricks to withdraw from the cement kiln, manufacturers that produce magnesia-chrome bricks must arouse great attention. Rongsheng Refractory Manufacturer provides high-quality refractory materials for cement kilns. Including direct bonding of magnesia chrome bricks, magnesia spinel bricks, and various wear-resistant castables. For more information about alkaline refractory bricks, please visit our website: https://rongshengrefractory.com/several-kinds-of-alkaline-refractory-bricks/.

Refractory Materials for Cement Rotary Kilns

Cement Kiln Lining Refractory Bricks Refractory Bricks for Cement Kiln

For the firing zone of the cement rotary kiln, a stable and strong kiln skin is required. Because it can protect the refractory lining and reduce the heat loss through the kiln body. A few centimeters of stable kiln skin can not only extend the life of the lining material by nearly 100% but also reduce the temperature of the kiln body by several hundred degrees. This means reducing heat loss by up to 25%.

When the local kiln appears thick skin, it is known as “ring formation.” It will hinder the operation of the kiln considerably. The most serious is that it has built an unfixed cross-section of the kiln, which hinders the steady flow of materials and fuel gas into the kiln. Once the kiln skin is looped, it cannot fall off by itself, and the kiln has to be stopped in order to deal with it. Rotary Kiln in the Cement PlantThe rate of kiln shutdown due to loop formation accounted for 80%. The change cycle ranges from once a month to more than once a week. It is for this reason that people have been studying methods to prevent or deal with kiln skin loops that hinder operation.

Therefore, it is considered whether it can be prevented by selecting suitable refractory materials, or at least the occurrence of ring formation can be reduced. Classification and Location of Kiln Skins and Ring Formation. According to the material flow, the kiln skin and ring formation in the preheater, rotary kiln, and cooler are divided into different types. According to these classifications, the raw material loop occurs in the decomposition zone where the material temperature is between 800°C and 1200°C. The sintering ring occurs at the front end of the firing zone where the material temperature is 1200~1350℃.

The clinker ring occurs at the end of the firing zone where the material temperature is 1200~1400℃. Another obstacle to the formation of kiln skins is the slurry ring on the wet long kiln. The skin on the suspension preheater and decomposition belt of the rotary short kiln, and the well-known “clinker mushroom tumor” on the cooler inlet chute. Refractory Material Affects the Possibility and Limit of Ring FormationThe chemical atmosphere in the kiln and the normal operating conditions affect the desired formation of the kiln skin and cause the trouble of material ring formation. However, refractory materials can also affect the stability of the kiln skin due to their different bonding strength. Experiments have shown that dolomite bricks have the strongest bonding force, followed by magnesia-chrome bricks and direct-bonded magnesia-chrome bricks (MgO content 60~70%), and magnesia spinel bricks (Almag 85) are the weakest.

Magnesia Aluminum Spinel Bricks for Cement Kilns

Magnesia Spinel Bricks for Cement Kilns

Magnesia Spinel Bricks Manufacturer. The “Mineral-Chemistry” study confirmed that the bonding force at the interface between the kiln skin and different bricks was measured by the mineral composition of the “kiln skin-brick” interface and the liquid “wetting” angle. Therefore, a layer of C3S enrichment zone with high refractoriness is formed on the interface between kiln skin and brick. This layer of C3S also contains tricalcium aluminate and ferrite phases. If the temperature drops below the stability limit of C3S (1250°C), C3S usually decomposes into C2S and secondary free CaO. But obviously, the incorporation of foreign ions, such as MgO, will stabilize C3S. Due to the decrease of the local CaO/SiO2 ratio in the area close to the surface of the brick, a C2S-rich boundary layer is formed, which results in a lower bonding force on the magnesia-chrome brick. In the presence of Cr2O3, C2S is partially stabilized.

However, if the interface temperature drops, that is, if the kiln skin becomes thicker, β-C2S will be converted to γ-C2S, with a volume expansion of 10%, resulting in “pulverization” and weakening of the binding force of the ring to the lining. So that the knot loops fall off. Magnesia spinel bricks have a particularly strong “chalking” effect. Although a C2S-rich layer is formed, the liquid phase obviously does not infiltrate the bricks to such an extent. On the other hand, there is no adequate amount of ions that can stabilize β-C2S. If the temperature drops in the contact zone, it is easier to form γ-C2S, so that the ring of materials will fall off. Because the magnesia spinel brick has a higher control of Fe2O3 content, it will not generate a C2S layer enriched with iron-free aluminate. The situation of magnesia chrome brick is the opposite because it contains higher Fe2O3.

Based on the previous observations, it is clear that magnesia spinel bricks can cause the ring to fall off, or prevent the formation of a C2S-rich ring layer that hinders operation. These loops mainly occur before and after the decomposition zone and the firing zone. Lining with magnesium spinel bricks can also prevent the formation of “clinker mushroom tumors” at the inlet chute of the cooler. As to whether the magnesia spinel brick can successfully eliminate the problem of skinning containing potassium sulfate, potassium carbonate, silica calcite, alkali metal sulfate, and alkali metal chloride, it is still worth discussing.

The looping of slurry in the cyclone, short dry kiln flue chamber, long wet kiln, and skin on the wall and top of the hot gas chamber of the grate preheater are all such problems. Obviously, the lining made of Almag85 grade magnesia spinel bricks shows that it can effectively prevent the formation of clinker rings, sintered rings, and raw material rings. Learn more about the magnesia alumina spinel bricks from Rongsheng Refractory Manufacturer.

Effect of Thermal Expansion Properties of Fused Bricks on Glass Furnaces

2024-03-21 by globalrefractory

The ignition and baking of the glass kiln are based on the physical and chemical properties of the refractory materials used in the kiln, that is the thermal expansion properties of the refractory materials. After heating and baking, the refractory material completes the internal crystal transformation and volume change, so that it can be used normally at high temperatures.

In the past, AZS bricks were expensive. Therefore, the kiln is not used or only used in small quantities in key parts. In the past two decades, with the development of high-efficiency and energy-saving kiln technology, AZS bricks have been widely used. AZS is increasingly used not only for the pool walls that are in contact with the glass liquid but also for the flame space. Due to the influence of traditional inertial thinking, most glass factories currently only consider the thermal expansion of silica bricks when baking kilns, but do not pay attention to the thermal expansion of AZS bricks. Therefore, fracture problems of AZS bricks often occur before and after the kiln is put into operation, which directly affects the life of the kiln.

Thermal Expansion Characteristics of AZS Bricks

AZS brick contains a certain amount of ZrO2, which is a homogeneous polycrystalline. That is, the same chemical composition can form three types of crystals with different structures and properties due to different temperature conditions. There are three types: monoclinic ZrO2, tetragonal ZrO2, and cubic ZrO2.

Changes in the crystal system are often accompanied by changes in volume. Taking 33# AZS as an example, it was found through experiments that when the temperature range is 0-1100°C, the bricks gradually expand as the temperature rises. When the temperature range is 1100-1200℃, the bricks shrink violently as the temperature rises. The linear expansion rate dropped from about 0.8% to about 0.6%, which is what is usually called abnormal expansion. This is caused by the transformation of the ZrO2 monoclinic system into the ZrO2 tetragonal system. When the temperature is higher than 1200°C, the bricks begin to expand again as the temperature rises.

It can be seen from laboratory testing data that the overall expansion is not large below about 1600°C.

Precautions when Baking the Glass Kiln

The kiln has a fire-amplification stage. The fire in the hot-air kiln is generally 900-1000℃. The practice has proved that most of the fractures of AZS bricks occur after a fire. The reason is that the temperature rise rate is too fast during the 1100-1200°C period when monoclinic ZrO2 transforms into tetragonal ZrO2. Therefore, it is generally required that the speed does not exceed 15°C/hour. Many manufacturers control it at 5°C/hour, and the speed does not exceed 15°C/hour in other temperature ranges. In this way, the AZS bricks have sufficient time to undergo crystal transformation and avoid fracture.

There is a temperature difference of several hundred degrees between the flame contact surface and the non-contact flame surface during the kiln baking process. In order for the outside of the brick to be able to undergo crystalline transformation safely, it is necessary to maintain a low heating rate within a larger temperature range. Therefore, the temperature range in the kiln is usually expanded from the theoretical 1100-1200℃ to about 1100-1350℃.

The upper 300-400 mm of the pool wall bricks are not insulated during normal production and need to be cooled. To reduce the temperature difference between the inside and outside of the kiln, insulation materials such as aluminum silicate fiber should be used for temporary insulation to prevent brick breakage. When the temperature reaches above 1500°C, the insulation fiber can be taken out.

When cooling the pool wall tiles, the cooling air inlet should be opened gradually. Generally, it is opened 5 times, and 20% is opened every hour.

The quality of the kiln’s work is related to the life of the kiln. Therefore, it is extremely important to correctly grasp the expansion performance of fused zirconium corundum bricks, standardize it in the kiln heating curve, and implement it carefully. Rongsheng refractory material manufacturer can provide a comprehensive range of lining bricks for glass kilns, including silica bricks, corundum bricks, corundum mullite bricks, AZS bricks, etc. Feel free to contact us for details.

Three Commonly Used Repair Materials for Kiln Refractory Brick Castables

2024-03-02 by globalrefractory

High-temperature-resistant inorganic adhesives have been widely used in the heat-resistant bonding of metals, ceramics, graphite, oxides, and other materials. Easy to use, used for direct bonding of high-temperature resistant materials. The coating can be sprayed directly on the surface of a high-temperature substrate of 400-1000°C. When the water evaporates, the coating will instantly adhere to the surface of the substrate, forming a uniform and dense high-temperature resistant protective coating with good thermal shock resistance.

High-Temperature Gunning Refractory Material for Lining Repair

It also has good strength at high temperatures, with an average compressive strength of 90Mpa and a tensile strength of 8Mpa at 1300°C. After applying high-temperature inorganic adhesive on the kiln windshield, hanging parts, and cracks, the bond will be firm and will not cause any damage to the kiln lining. Adhesives are easy to use and play a very important role in the normal operation of the furnace. It has been successfully used in rotary kilns, drying furnaces, and combustion chambers in the cement industry. Heating furnaces and smelting furnaces in the machinery industry. Electric furnaces, roasters, and blast furnaces in the metallurgical and chemical industries. Tunnel kilns in the ceramic industry, boilers in the thermal power industry, and other types of kilns.

The high-temperature-resistant expansion glue uses a high-temperature inorganic silicate modified solution as the film-forming material, and is composed of rare earth oxides, re-expanded mullite, and vaporized SiO2 powder as fillers. The cured coating film has a temperature resistance of up to 2200°C and can maintain good thermal stability, bonding performance, wear resistance, and corrosion resistance in high-temperature environments. The coating has a high linear expansion coefficient, and the coating expansion rate can reach 15% under high-temperature conditions.

The kiln lining protective coating uses the company’s special high-temperature resistant inorganic silicate modified solution as the film-forming substance and is composed of nano-scale alumina, silicon carbide, rare earth oxides, ceramic fibers, etc. The cured coating film has high-temperature resistance, which can reach 1800°C, thermal shock resistance, high adhesion, good heat insulation, strong aging resistance, and convenient construction. It can be sprayed directly on the surface of various materials lining the kiln, including insulation bricks, castables, metals, ceramics, refractory fibers, quartz sand, silicon carbide, quartz glass, etc.

High-Alumina Polylight Bricks are High-Performance Lightweight Insulation Materials

2024-02-04 by globalrefractory

High-aluminum poly-light brick is a high-performance lightweight thermal insulation material with excellent performance and wide application prospects. Rongsheng Refractory Materials Manufacturer has an in-depth understanding of the characteristics, application fields, and preparation processes of high-alumina poly-light bricks. It can provide high-performance lightweight insulation materials for high-temperature industrial furnaces, including high-aluminum poly-light bricks, mullite insulation bricks, micro-nano insulation series, etc.

High-Alumina Poly Light Insulation Brick

Characteristics of High Alumina Poly Light Bricks

High-aluminum poly light brick is a kind of lightweight brick made of high-aluminum clinker as the main raw material, adding an appropriate amount of polymer and additives, and sintering at high temperatures. It has the following characteristics:

Lightweight and high strength. High-aluminum poly-light bricks are lightweight and high-strength. Its density is only 0.6-1.0g/cm3, but its strength is as high as 5-20MPa.
High fire resistance. The fire resistance of high-alumina poly light bricks is as high as 1300°C, which can meet the protection needs of high-rise buildings and high-temperature equipment.
Heat insulation. High alumina poly-light bricks have excellent thermal insulation properties. Its thermal conductivity is only 0.2-0.4W/(m·K), which can reduce the energy consumption of buildings.
Strong corrosion resistance. High alumina poly light bricks can resist the erosion of various chemical substances, such as acids, alkalis, salts, etc. Therefore, it is widely used in the chemical industry and other fields.
Convenient construction. High alumina poly-light bricks have standard sizes and are easy to install and construct. At the same time, its lightweight also facilitates transportation and installation.

Application Fields of High Alumina Poly Light Bricks

High alumina poly light bricks are used in kiln linings in metallurgy, machinery, ceramics, chemical, and other industries. It is not corroded by solutions and is used in insulation layers. It is an ideal energy-saving product.

RS High-Alumina Poly Light Insulation Brick

Application Advantages of High Alumina Poly Light Bricks

Lightweight. Compared with traditional refractory bricks, high-alumina poly-light bricks are lighter in weight and are easier to transport and construct. It reduces the overall load of the furnace body and reduces the requirements for the furnace body support structure.

Reduce energy consumption. High-alumina poly-light bricks have good thermal insulation properties and can effectively reduce heat transmission and thermal radiation losses. By using high-aluminum polylight bricks, fuel consumption can be reduced and energy efficiency improved.

Extended service life. High-alumina polylight bricks have excellent fire resistance and corrosion resistance, which can extend the service life of the furnace body. It can reduce ablation and wear inside the furnace and ensure the stability and safety of the furnace structure.

The technology is widely used. Due to the characteristics and advantages of high-alumina poly-light bricks, it has been widely used in various industrial fields. Such as steel, metallurgy, chemical industry, building materials, and other industries, especially suitable for kilns and furnaces in high-temperature environments.

Preparation Technology of High Alumina Poly Light Bricks

The preparation process of high-alumina poly light bricks mainly includes the following steps:

Ingredients. Mix high-aluminum clinker, polymers, additives, and other raw materials evenly according to a certain proportion.
Forming. Put the mixed raw materials into the mold and press it into shape.
Dry. The molded green body is dried to remove moisture from the green body.
High-temperature sintering. The dried green body is put into a high-temperature kiln for sintering, turning it into a lightweight brick with excellent properties.
Finished product inspection. Conduct quality inspection on high-alumina poly-light bricks, and qualified products can be shipped out of the factory.

Rongsheng High Alumina Poly Light Brick Manufacturer

As a high-performance lightweight thermal insulation material, high-aluminum polylight bricks have broad application prospects and important practical value. This article introduces the characteristics, application fields, and preparation process of high-aluminum poly-light bricks, providing a reference for readers to understand high-aluminum poly-light bricks. With the continuous development of science and technology, it is believed that high-alumina poly-light bricks will be more widely used in the future. To purchase high-quality lightweight insulation products, please contact us.

Carbon Fiber High-Temperature Graphitization Furnace Corundum Material

2024-01-20 by globalrefractory

The main purpose of the carbon fiber graphitization treatment furnace is to induce the graphitization crystal orientation of the fiber to increase the elastic modulus of the carbon fiber. The production of carbon fiber is carried out in a high-temperature sealed graphitization furnace. Both ends of the furnace are sealed with high-purity argon gas. The heating element is made of graphite material, and the graphite tube is both the furnace tube and the heating element of the high-temperature furnace. The heating temperature is generally between 2500°C and 2800°C.

The life of the graphitization furnace depends on the properties of the refractory material. The furnace shell of the graphitization furnace is rolled from ordinary carbon steel plates. Special refractory materials are used as insulation materials in the shell, which are generally composed of heat-resistant layer, heat insulation layer and protective layer. In order to ensure the airtightness of the furnace, the inner surface of the refractory lining must be round and smooth. Otherwise, the air tightness of the lining will be affected and it will not be resistant to airflow erosion. In addition, there are temperature measuring holes and pressure measuring holes on the furnace.

Graphitization Furnace Corundum Material

When using the graphitization furnace, great attention must be paid to temperature changes caused by rapid cooling and rapid heating. When production is stopped for maintenance, if the furnace cannot be kept warm by gas or other heat sources, the front and rear of the furnace must be tightly blocked to prevent the furnace from bursting due to rapid cooling. Prevent metal objects from entering the furnace and contacting the corundum lining, because metal and corundum materials generate a low melting point eutectic, which reduces the refractoriness and causes partial melting of the furnace body. The cooling water jacket must be designed reasonably to prevent burnout due to local overheating and to prevent water from entering the furnace and causing the furnace body to explode. In addition, carbon black fillers must not be affected by moisture. The graphitization furnace must be covered, and the flue gas must be treated to meet standards before it can be discharged.

Special insulation materials are selected as insulation materials for high-temperature graphitization furnaces, which refer to single materials such as high-purity oxides, non-oxides and carbon with melting points above 1800°C. Or they are made of various composite materials and produced using traditional production techniques or special production techniques. Its products are new refractory materials with special properties and special uses. The main function of high-temperature graphitization furnace insulation materials is to reduce heat energy loss and save energy. Ensure the needs of production process and improve equipment capabilities. Improve working conditions, achieve safe production, and extend the operation period of equipment.

Graphitization furnace insulation materials play the dual roles of heat preservation and electrical insulation in the graphitization furnace. Insulation materials have a very important influence on the temperature rise of graphitization furnace. The quality and thickness of the insulation material determine to a large extent the thermal energy utilization efficiency of the graphitization furnace and the temperature difference in various parts of the furnace, and determine the energy consumption during graphitization of carbon fiber. Insulation materials are also related to the safety and performance of refractory masonry and furnace building structures. The electrical insulation of the insulation material is key to ensuring that electric current acts effectively on the furnace tube. It requires low thermal conductivity and good thermal insulation performance. It has high resistivity and good electrical insulation properties. Does not hinder the discharge of gas in the furnace. Does not react with products in the furnace at high temperatures. Cheap and easy to purchase in large quantities.

Corundum (α-AL2O3) is produced by electrofusion or sintering of industrial alumina or bauxite ore. The mineral composition of corundum is a-AL2O3, its density is about 3. 85 ~ 4. 01g/cm3, its melting point is 2050°C, and its deformation temperature is 1750°C. It has good thermal conductivity, good electrical insulation and chemical stability, and can resist the erosion of NaOH, Na2CO3, etc. And it has the ability to resist the action of reducing agents (such as hydrocarbon chemicals, hydrogen and free metals, etc.) below 1800°C. It has the characteristics of high mechanical strength under high temperature, good thermal shock resistance, strong corrosion resistance, and small thermal expansion coefficient. It is the best lining material for various high temperature furnaces.

[Tips] Carbon fiber is a fibrous carbon material. Its biggest feature is its high elastic modulus and light weight. The deformation resistance of high elastic modulus carbon fiber is more than 2 times greater than that of steel and 5 to 6 times greater than that of aluminum alloy. The specific gravity of carbon fiber is less than 1/4 of steel and 1/2 of aluminum. Carbon fiber is a fiber with a carbon content of more than 90%, which is made from polyacrylonitrile fiber, pitch fiber, viscose fiber or phenolic fiber through oxidation, carbonization and other processes. Those with a carbon content higher than 99% are called graphite fibers.

Insulating Bricks JM23 Low Iron for Sale Cheap

2023-12-192023-12-15 by globalrefractory

Lightweight mullite insulation brick is a kind of insulation brick, which is an insulating refractory brick made of mullite as aggregate. Mullite insulation bricks are white, can be directly exposed to flames, and have high refractoriness. Mainly used in hot blast furnace tops, blast furnace shafts, and bottoms, glass melting furnace regenerators, ceramic sintering kilns, dead-end furnace linings in petroleum cracking systems, etc.

Lightweight mullite insulation bricks

The dimensions of conventional lightweight mullite insulation bricks are 230 x 114 x 65mm. Common models of lightweight mullite insulation bricks include JM23, JM26, JM28, and JM30. The main difference between them is the content of aluminum oxide and iron oxide. Different contents can withstand different refractory temperatures, thermal conductivity, and thermal expansion rates.

Low Iron JM23 JM26 JM28 Mullite Insulation Bricks

Characteristics of low-iron JM23 lightweight mullite insulation bricks

Low thermal conductivity and good thermal insulation effect.
Low thermal melt. Due to low thermal conductivity, mullite series lightweight insulation bricks store very little heat energy. The energy-saving effect is obvious in intermittent operation.
Low impurity content and very low oxide content such as iron metal. Therefore, the fire resistance is high. The higher aluminum content allows it to maintain good performance under a reduced atmosphere.
High hot compressive strength.
The appearance dimensions are precise, speeding up the masonry work and reducing the usage of refractory mud. The strength and stability of the masonry are ensured, thereby extending the life of the lining.
It can be processed into special shapes to reduce the number of bricks and joints.

RS refractory material manufacturer can provide lightweight mullite insulation bricks, with standard sizes and customized sizes. Low iron JM model, contact us for a free quote and sample.

Lightweight mullite insulation bricks for industrial kilns

Lightweight mullite insulation bricks for industrial kilns are a widely used energy-saving material. Has the following characteristics. Lightweight. The density of mullite insulation bricks is less than or equal to 1000 kg/cubic meter. It is much lighter than traditional stone or metal thermal insulation materials, which can reduce the burden and weight of the kiln. Insulating properties. Mullite insulation bricks have high porosity and large porosity, which can effectively improve thermal insulation performance and reduce heat loss and transmission. Durability. Mullite insulation bricks have very good durability due to their porous structure. Its stability and durability can be guaranteed even in high-temperature environments. Easy to process. Mullite insulation bricks can be mechanically crushed or pressed into different shapes and sizes for easy use and processing. In industrial kilns, mullite insulation bricks are often used for thermal insulation and preventing heat loss. This material can effectively reduce the energy consumption and cost of the kiln, and improve production efficiency and safety.

Low-iron JM23 lightweight mullite insulation brick manufacturer and RS refractory insulation brick manufacturer produce mullite lightweight insulation bricks with industrial Al₂O₃ powder, clay, well-sintered bauxite, and kyanite as the main raw materials. Add wood chips (1mm screen) and polystyrene balls (diameter 0.2~0.5mm) to prepare lightweight bricks. It has the characteristics of high-temperature strength, low porosity, and corrosion resistance. Widely used in high-temperature industrial kiln linings.

Mullite insulation brick is a new type of thermal insulation refractory material, low iron JM23 lightweight mullite insulation brick. According to the difference in density, it can be divided into lightweight mullite insulation bricks and corundum mullite bricks (also called heavy mullite insulation bricks). Mullite insulation bricks are divided into JM23, JM26, JM28, and JM30 according to their grades. Mullite insulation bricks are divided into 1350 mullite insulation bricks, 1450 mullite insulation bricks, 1550 mullite insulation bricks, etc. according to different use temperatures. Moreover, 1550 mullite bricks can be directly exposed to flames and have the characteristics of high-temperature resistance, small thermal conductivity, and significant energy-saving effects.

Mullite insulation brick product price

The price of mullite insulation brick JM23 is 2,600 yuan/ton, and the use temperature is 1,350°C.
The price of mullite insulation brick JM26 is 3,200 yuan/ton, and the use temperature is 1,450°C.
The price of mullite insulation brick JM28 is 4200 yuan/ton, and the use temperature is 1550℃.
The price of mullite insulation brick JM30 is 4,800 yuan/ton, and the use temperature is 1,600°C.

JM23 lightweight mullite insulation bricks, the body density of lightweight mullite insulation bricks is 0.6, 0.8, 1.0, 1.2g/cm3. Mullite lightweight thermal insulation bricks are suitable for high air temperature metallurgical hot blast furnaces, molten steel impactors, slag lines, the roof of steelmaking electric arc furnaces, the forehearth of glass melting furnaces, regenerator arches, and superstructures. The lining of ceramic sintering kilns, ceramic roller kilns, tunnel kilns, electric porcelain drawer kilns, dead-end furnaces of petroleum cracking systems, glass crucible kilns and various electric furnaces. The walls of the clarifier can be in direct contact with flames.

To learn more about RS low-iron JM23 lightweight mullite insulation bricks, please contact us.

The Use of High Alumina Bricks in the Medium Temperature Zone of Hot Blast Stoves

2023-11-24 by globalrefractory

The selection of refractory materials for hot blast stoves is mainly determined by the temperature of the hot blast. When the wind temperature is lower than 900°C, clay bricks are generally used, and their service life can reach about 20 years. When the air temperature is between 900 and 1100°C, high-alumina bricks, mullite bricks, or sillimanite bricks are used for the furnace lining and checker bricks in the high-temperature part. When the air temperature is higher than 1100°C, high alumina bricks, mullite bricks, and silica bricks are generally used as furnace lining or checker bricks.

In recent years, newly built or renovated blast furnace hot blast stoves in various countries mainly adopted external combustion type. The supply air temperature is 1200~1350℃, and the vault temperature is generally 1500~1550℃, even close to 1600℃. Therefore, the high-temperature parts of the furnace lining and the upper layer of checker bricks are generally constructed with silica bricks, which has better results.

Low Creep High-Alumina Bricks for Hot Blast Stoves

What is the Alumina Content of High-Alumina Refractory Bricks Used in Hot Blast Stoves?

Regarding the high alumina refractory bricks with alumina content used in a new hot blast stove, it is generally recommended to choose high alumina refractory bricks with higher alumina content. High-alumina refractory bricks usually have an alumina content between 48% and 80%, which can provide better fire resistance and corrosion resistance.

The use of high alumina bricks in the medium temperature zone and high and low temperature alternating zones of hot blast furnaces.

The medium temperature area of the hot blast stove (600~1150℃) refers to the middle part of the flame in the combustion chamber, and in the regenerative type it refers to the middle part of the checker bricks, the transition section from high temperature to low temperature. In this area, low creep high alumina bricks or high-grade andalusite bricks are generally selected. For internal combustion and external combustion hot blast stoves, the area from the top of the burner to the vicinity of the hot blast outlet. As well as the top-fired hot blast stove, the space enclosed by the inner wall of the burner – the pre-combustion chamber, is a high and low temperature alternating area (35~1100℃). The temperature changes in this area are mainly caused by the mutual conversion of the “combustion-air supply” cycle of the hot blast stove. It is advisable to choose andalusite or cordierite bricks with good thermal shock resistance.

The hot air ducts of hot air stoves are also traditionally made of andalusite bricks. In recent years, with the increase in wind temperature, refractory bricks using andalusite-mullite composite have also appeared.

Kinds of Low-Creep High-Alumina Bricks for Hot Blast Furnace

There are many types of high alumina bricks, and their properties vary greatly depending on the Al2O3 content and crystal form.

Low creep high alumina bricks

The main characteristic of low creep high alumina bricks is their good creep resistance. Domestic production of low creep high alumina bricks generally uses bauxite as the main raw material. The “three stone” minerals (andalusite, sillimanite, and kyanite) are additives. Among the “three stone” minerals, the addition of andalusite is more common.

Adding tristone to solve the creep resistance problem of high-alumina products lies in the final mulliteization of tristone. During the firing process of high alumina bricks, the three stones will undergo mullite formation, and the reaction will directly generate mullite. The accompanying SiO2 will react with high-alumina materials again, causing secondary mulliteization. After the final firing is completed, the three stones in the crystal phase will be completely converted into mullite, and n(Al2O3)/n(SiO2) is close to 3:2, forming a stable columnar mullite crystal phase structure. This structure determines that high alumina bricks have good creep resistance.

Andalusite bricks

Andalusite bricks have good high-temperature properties, and their high-temperature creep resistance is better than high-alumina bricks and most mullite bricks. Moreover, the volume expansion associated with high-temperature mullite formation is small, and it has good thermal shock resistance. It is an ideal low-creep refractory material.

The main raw material used in the production of andalusite bricks is andalusite, and the proportion is generally higher than 40%. If it is made into andalusite-mullite composite brick, a part of mullite or corundum should also be added. If the mullite raw material is synthetic mullite. The crystals should be thicker to reduce the number of grain boundaries, weaken the slip of the crystals at high temperatures, and enhance the creep resistance of the bricks.

Cordierite bricks

The linear expansion coefficient of cordierite bricks is small. The linear expansion coefficient at 20~900℃ is (1.25~1.92)×10-6℃-1, and it has good thermal shock resistance. However, the refractoriness of cordierite is low, only 1370℃. When the firing temperature is too high, a glass phase is easily produced. Pure cordierite bricks cannot be well used in high and low-temperature alternating areas due to their low operating temperature range. In actual production applications, cordierite is often added as an auxiliary raw material, which has a significant effect on improving the thermal shock resistance of bricks.