KilnRefractory, Author at Kiln Refractories Blog

Price of Mullite Insulation Bricks with Bulk Density 1.0g/cm3

April 2, 2024April 2, 2024 KilnRefractory

Mullite brick is a high-quality refractory brick. Mullite brick is made of high-quality high-alumina bauxite clinker as the main raw material. Mix the appropriate amount of clay, ingredients, and water to create a malleable mud or mud. High-quality thermal insulation bricks that are extruded and fired at high temperatures.

Rongsheng Lightweight Mullite Insulation Bricks for Sale

Mullite Insulation Brick Price

According to the brand name, mullite bricks are generally divided into JM23 mullite bricks, JM26 mullite bricks, JM28 mullite bricks, and JM30 mullite bricks. The price of mullite bricks is generally between 2,800 yuan/ton and 4,500 yuan/ton. So, how many mullite bricks are there? The common body densities of mullite bricks are 0.8g/cm³ and 1.0g/cm³. There are about 735 mullite bricks with a body density of 0.8g/cm³ per ton, and there are about 588 mullite bricks with a body density of 1.0g/cm³ per ton. Then you can calculate how much a mullite brick costs.

For example, a ton of 0.8 JM23 mullite bricks is 2,800 yuan, so the price of a piece of JM23 mullite bricks is 2,800 yuan ÷ 735 pieces = 3.8 yuan. 1.0 A ton of JM23 mullite bricks is 2,700 yuan, so the price of a piece of JM23 mullite bricks is 2,700 yuan ÷ 588 pieces = 4.59 yuan.

According to changes in market conditions, if a ton of 0.8 JM28 mullite bricks costs 3,500 yuan, then the price of a piece of JM23 mullite bricks is 4,500 yuan ÷ 735 pieces = 6.12 yuan. 1.0 A ton of JM28 mullite bricks is 4,200 yuan, so the price of a piece of JM23 mullite bricks is 4,200 yuan ÷ 588 pieces = 7.14 yuan.

Rongsheng Mullite Brick JM28 Factory

Zhengzhou Rongsheng Kiln Refractory Materials Factory is a professional manufacturer of refractory bricks and castables. The company produces refractory products of different specifications, sizes, and standards for different usage environments, and has a professional refractory construction team. The company’s refractory brick products mainly include mullite bricks, high alumina refractory bricks, clay refractory bricks, lightweight insulation bricks, castables, silica bricks, and magnesia bricks. Rongsheng Company has a complete and scientific quality management system and perfect customer service. If you need to purchase insulation material products for your high-temperature industrial furnace project, please contact us.

JM23 JM26 JM28 Mullite Insulation Bricks for Furnace Insulation

The Difference between Lightweight Mullite Insulation Bricks Jm23/Jm26/Jm28/Jm30

The lightweight mullite insulation bricks Jm23/Jm26/Jm28/Jm30 have different indicators such as alumina content, refractoriness, volume density, and normal temperature compressive strength, which affect the insulation performance and stability. When selecting, physical and chemical indicators need to be considered based on specific needs.

Jm23/Jm26/Jm28/Jm30 in lightweight mullite insulation bricks respectively represent different grades of brick numbers. Different grades of lightweight mullite insulation bricks will have differences in insulation performance, physical and chemical indicators, and scope of use. So what are their differences?

Al2O3 content is different

The alumina content of lightweight mullite insulation bricks Jm23/Jm26/Jm28/Jm30 is 38-44%, 50-58%, 65-70%, and 70-73% respectively. The higher the grade, the higher the alumina content, which affects the thermal insulation performance and fire resistance.

Different refractoriness

The four levels of lightweight mullite bricks have refractory resistances of 1350°C, 1430°C, 1540°C, and 1600°C respectively. The higher the grade, the higher the refractoriness. This is because as the alumina content increases, the refractory degree also increases. The better the stability of lightweight mullite insulation bricks in high-temperature environments.

Different volume density

Among them, the volume density of JM23 is 1.3g/cm3, the volume density of JM26 and JM28 is the same at 0.8g/cm3, and the volume density of JM30 is 1g/cm3.

Different normal temperature compressive strength

The compressive strengths of lightweight mullite insulation bricks Jm23/Jm26/Jm28/Jm30 are 1.3Mpa, 2Mpa, 3Mpa, and 3.5Mpa respectively. The higher the normal temperature compressive strength, the load-bearing capacity and service life of the brick will increase accordingly.

In addition to the above common differences, they have differences in thermal conductivity, reheat line change rate, etc. These indicators reflect the thermal conductivity and stability of the material, and we can choose based on detailed physical and chemical indicators when selecting.

Rongsheng Insulation Bricks Materials for Sales

Proper insulation of the kiln can also save production energy and production costs. Rongsheng manufacturer has many successful cases in kiln insulation. Help enterprises reduce the temperature of the outer wall of the kiln by 50~60℃. Moreover, our new insulation material products have also been tested and will soon be promoted to various industrial kilns. Contact us for free information and quotations on the latest insulation bricks.

High-Strength Wear-Resistant Silicon Carbide Castable

March 8, 2024 KilnRefractory

Silicon carbide castable uses high-purity silicon carbide (SiC) raw material as the main component and adds a certain proportion of micro-powder additives. An unshaped refractory material produced with high-purity refractory cement as a binder. It has excellent properties of high-temperature resistance, wear resistance, erosion resistance, peeling resistance, erosion resistance, and crusting resistance. Amorphous refractory materials with silicon carbide as the main raw material also include silicon carbide spray coatings, silicon carbide plastics, etc., which can be poured, sprayed, and smeared.

Advantages of Silicon Carbide Castables

Anti-wear. Since the main component of the material is silicon carbide (SiC), it is also called emery. There are very few natural ones, and those used in industry are all synthetic raw materials. It has two crystal forms. The low-temperature form of β-SiC has a cubic structure; the high-temperature form of α-SiC has a hexagonal structure. Its true density is 3.21g/cm3, and its decomposition (sublimation) temperature is 2600°C. It is a hard material with a Mohs hardness of 9. Synthetic SiC powder is used as an abrasive. The grinding ability of silicon carbide is 0.25~0.28, which is higher than corundum.
High-temperature resistance. Silicon carbide has good high-temperature resistance. Under normal pressure, the inconsistent melting temperature of silicon carbide is 2760°C, reaching 625MPa.
Anti-erosion, anti-oxidation and anti-scaling. When heated to 1000°C, the surface of SiC is oxidized and a layer of SiO2 protective film is formed. This film hinders the diffusion of oxygen and slows down the oxidation rate. The silicon carbide covered by the film is protected and the service life of the silicon carbide material is improved.

At 1300°C, cristobalite begins to precipitate in the film. The crystal form transformation of cristobalite causes cracking of the film and accelerates the oxidation rate.

At 1500~1600℃, the oxidation rate accelerates, but the SiO2 layer produced is also thick, and silicon carbide can still work for a long time. When the temperature rises to 1627°C, the SiO2 layer is destroyed and the silicon carbide oxidation reaction intensifies. Therefore, 1627°C is the highest temperature at which silicon carbide can work in an oxidant-containing atmosphere.

The chemical properties of silicon carbide are relatively stable and have good acid resistance. Silicon carbide does not react with boiling hydrochloric acid, sulfuric acid, or nitric acid. When the temperature is ≤1300℃, it will not be corroded by H2, N2, and COR2O, and it will be corroded by oxides above 1000℃. At high temperatures, silicon carbide is corroded by Cl2, F2, and H2, and can also react with H2O. When the temperature is ≥1370°C, silicon carbide and Cr2O3 react to form metal silicide.

Silicon carbide is not suitable for cutting steel. When the temperature rises, SiC will react with Fe to form ferrosilicon alloy and iron carbide. But silicon carbide can be used to grind cast iron. This is because cast iron has a high carbon and silicon content and is not sensitive to the reaction of silicon carbide.

Thermal shock resistance. When the silicon carbide powder is 150 mesh, SiC is not completely oxidized. Creating gaps or partial gaps around the SiC particles improves the thermal shock resistance and strength of the castable. The SiC that has not been completely oxidized also plays the role of particle reinforcement.

High conductivity. Silicon carbide has strong electrical conductivity and is a semiconductor. When the temperature reaches 2000°C, the electrical conductivity of silicon carbide is equivalent to that of graphite.

Silicon Carbide Castable Refractory Lining

Application of Silicon Carbide Castables

Molten iron preconditioner linings, cupola furnaces, and induction furnace linings in the steel industry.
Combustion chamber side wall linings and boiler tube protective linings for waste incinerators in the solid waste treatment industry.
In the cement industry, the cement kiln preheater lining, rotary kiln head, and grate cooler wear piers.
The cyclone separator lining the body of thermal power plants in the electric power industry, the combustion chamber, lining, and high-temperature separator return part of the circulating fluidized bed furnace.
Firing kiln shed panels for the ceramics industry.
Reduction of furnace linings such as silicon outlets and aluminum outlets in the non-ferrous metal smelting industry.
Biomass pellet stove burners and other easy-to-wear parts in the energy industry.

Introduction to Silicon Carbide Castable Mix Ratio and Performance

There are very few natural silicon carbides, and most of them used in industry are synthetic raw materials, commonly known as emery. Silicon carbide is one of the non-oxide refractory raw materials commonly used in the field of refractory materials. Clay-bonded silicon carbide castables, oxide-bonded silicon carbide, nitride-bonded silicon carbide, recrystallized silicon carbide, reaction sintering siliconized silicon carbide and other products produced from silicon carbide as raw materials, as well as amorphous refractory materials. It is widely used in blast furnaces, zinc smelting furnaces, ceramic industry kiln furniture, etc. in the metallurgical industry.

Silicon carbide castable has the characteristics of high strength, good wear resistance, and strong slag resistance. The operating temperature is 1500-1700°C. It is generally used in parts that are prone to wear such as cyclone furnaces, boiling furnaces, and boilers, and can meet the technical requirements of thermal equipment. Mix ratio and properties of silicon carbide castables. The density of the aluminum phosphate solution is 1.5g/cm³. The sample without coagulant is dried at 110°C. Aluminum powder with a fineness of 0.09mm is greater than 85%. For castables with added alum powder, the high-temperature compressive strength at 1200°C is 22.5MPa, the load softening temperature at 4% deformation is above 1710°C, and its starting point temperature is 1680°C.

When the kiln lining is thicker, the particle size of the refractory aggregate should be increased to 5mm or larger to reduce the specific surface area of the refractory raw materials. Reduce the amount of aluminum phosphate solution and improve the performance of silicon carbide castables. As we all know, silicon carbide castables will begin to oxidize in an oxidizing atmosphere at about 1000°C. Significant oxidation occurs at 1350°C, and a SiO2 protective layer is formed at the same time, which can prevent SiC from continuing to oxidize. Therefore, aluminum phosphate silicon carbide castable is used in an oxidizing atmosphere, and its long-term use temperature is about 1500°C.

It should be pointed out that as a binder for silicon carbide castables, aluminum phosphate is more commonly used. There are also magnesium phosphate, sodium phosphate, zinc phosphate, boron phosphate, calcium phosphate ammonium phosphate, etc., which can also be used as binding agents but are rarely used in actual projects. Aluminum phosphate binder can be used with any silicon carbide castable. The prepared silicon carbide castable has better performance and achieves better use results. However, the reaction between silicon carbide castables and magnesia materials is severe. When using aluminum phosphate solution as a binding agent, inhibitors or retarders should be added, or solid aluminum phosphate-containing inhibitors should be used as a binding agent, both of which can achieve good construction and use effects.

Rongsheng Kiln Refractory Material Manufacturer

Of course, except for silicon carbide castables whose main component is silicon carbide. There are also silicon carbide added to high aluminum and corundum amorphous refractory materials. SiC can be used as the main component to make SiC castables, or it can be used as an additive component to improve the properties of other castables, especially slag resistance and thermal shock stability. In 1999, Wang Xitang et al. researched and developed the Al2O3-SiC-C blast furnace tap trough self-flowing castable. The castable has high strength, good corrosion resistance, high iron flow, and good thermal shock resistance and oxidation resistance. The most common application of SiC in monolithic refractory materials is for the working lining of blast furnace tap trenches. It has a history of more than 20 years and has good results. At present, Al2O3-SiC-C castables are commonly used in larger blast furnaces at home and abroad, which greatly extends the service life of the iron trench.

Thermal Insulation Materials for Aluminum Electrolytic Cells

February 1, 2024 KilnRefractory

Aluminum electrolytic cell is the main thermal equipment for aluminum electrolysis production. Electrolytic aluminum is the process of converting aluminum in alumina into metallic aluminum. There is an outstanding problem in the aluminum electrolytic plant. The bottom of the tank is cold. Improvement measures include blocking the windows in the lower part of the two-story structure, laying bricks within the tank shell frame, and coating the outside of the tank with an insulation layer.

Aluminum electrolytic cells are divided into bottom type and bottomless type according to the structure of the tank. According to the shape of the tank shell, it is divided into square and rectangular. According to the anode structure, it is divided into a prebaked anode and a continuous self-baked anode. According to the conductive mode, it is divided into side conductive and upper conductive.

The lining materials used in aluminum electrolytic cell-related equipment include calcium silicate boards, clay-insulating refractory bricks, clay refractory bricks, and dry anti-seepage materials. Cathode carbon block, carbon paste, water glass asbestos putty, silicon nitride silicon carbide thermal insulation coating, etc. The heat insulation layer refractory material can be placed between the tank bottom and the asbestos board to increase the heat insulation. The thermal insulation performance is more than five times stronger than calcium silicate boards of the same thickness.

High-Temperature Thermal Insulation Coating for Aluminum Electrolytic Cells

High-temperature thermal insulation coating is processed from specially synthesized inorganic silicate solution, aluminum silicate fiber, heat-reflective material, and selected hollow ceramic beads. Water-based, environmentally friendly, non-toxic, and harmless. The characteristics of high-temperature thermal insulation coating products for aluminum electrolytic cells are as follows:

Thermos bottle thermal insulation mechanism.
The hollow ceramic beads in the coating greatly reduce heat convection.
Inorganic film-forming substances with relatively low thermal conductivity.
Sound insulation and noise reduction, fire-retardant, wear-resistant and pressure-resistant, insulation-resistant and puncture-resistant, acid and alkali-resistant, lightweight, easy construction, and long service life.

The curing principle of high-temperature thermal insulation coating for aluminum electrolytic cells:

Silicate coatings are composed of a variety of silicates and a small amount of organic and inorganic binders. Its curing principle: a special silicate solution acts as a gelling agent. Aggregation process:

The condensation of silanol and the condensation between silanol and the aluminum hydroxyl group of the silicate. Form a three-dimensional skeleton network.
Silicates are polymerized according to layered and framework molecular-level silicone groups. The mixed metal oxide acts as a space filler between the three-dimensional skeleton of the main body.

Application of High-Temperature Thermal Insulation Coating

Surface painting. High-temperature molds and outer surfaces of injection molding machines. On the inner surface of high-temperature flues and exhaust pipes. Paint the thermal insulation surface of hot water tanks and dye vats.
Ceramic production, ceramic roller kiln, refractory rotary kiln. Cement plant applications, cement rotary kiln, preheater, decomposition furnace.
Steel plant applications, ring furnaces, heating furnaces, and quenching furnaces. Molten steel tundish. Blast furnace workshop steel structure insulation, coke oven.
The inner wall of the furnace shell of the smelting furnace in the metallurgical copper industry. The inner wall of the electrolytic aluminum furnace (aluminum industry).
The outer surface of the power plant turbine shell/shaft seal; and the outer surface of the steam pipe are painted. Petrochemical heating furnace, vacuum heating furnace, cracking furnace.
The top of the boiling furnace is insulated and sealed. Industrial heating furnace. Vacuum furnace insulation.
Driving cab (Crane Crane). Explosion-proof vehicles, asphalt vehicles, engineering vehicles, and military armored vehicle chassis.
Spinning box, high-temperature oven surface. New energy batteries and intermediate frequency furnaces.

Calcium Silicate Board for Aluminum Electrolytic Cell

Calcium silicate board is a new type of building material, also called “calcium silicate board”, “calcium magnesium silicate board”, “MgO board”, etc. It is a composite building material made of a variety of materials and has multiple functions such as fire protection, waterproofing, sound insulation, heat preservation, and corrosion resistance. Calcium silicate boards can be widely used in various fields such as building walls, roofs, partitions, and floors. It has high economic and social benefits.

The main components of calcium silicate board are inorganic mineral fibers as reinforcing materials, and siliceous, calcium, and other materials as the main materials. These materials are made by high-temperature pressing after certain stabilization treatments. Calcium silicate board has good flexural strength, tensile strength, and compressive strength. At the same time, it also has multiple functions such as fire resistance, corrosion resistance, sound insulation, and heat preservation.

Calcium silicate boards also have a wide range of applications and can be used on walls, roofs, partitions, and floors. Calcium silicate board has the characteristics of water resistance, corrosion resistance, etc. Therefore it is widely used in relatively humid places.

Compared with traditional building materials, the installation process of calcium silicate boards is simpler and faster. When installing calcium silicate boards, you only need to install them directly on the frame, and few other materials are used. Therefore, no construction waste and pollutants will be generated. As a thermal insulation material, calcium silicate boards are also widely used in aluminum electrolytic cells.

How to Solve the Heat Insulation Problem of Cement Kiln?

December 28, 2023 KilnRefractory

The sintering system of the cement plant has been operating at high temperatures for a long time. Choosing a better insulation material can effectively reduce heat dissipation by lowering the shell temperature without increasing or even reducing the insulation thickness. In order to maintain a better thermal condition of the system, thereby reducing energy consumption, reducing production costs, achieving the goals of energy conservation, environmental protection, and increasing production and efficiency.

The traditional custom for thermal insulation materials in fired systems is to choose microporous calcium silicate boards or ceramic fiber boards. Its thermal insulation performance can no longer meet the current higher needs for thermal insulation and energy saving. New nano-scale microporous thermal insulation materials, referred to as nano-thermal insulation materials, provide technical and material support for the higher requirements for thermal insulation and energy saving of cement kiln firing systems and the improvement of system production capacity.

Inorganic Thermal Insulating Boards in RS Factory

Micro-nano Thermal Insulation Materials for Cement Kilns

Recently, cement companies have replaced the original insulation materials of cement burning systems with nano-insulation materials. A good thermal insulation effect has been achieved, which can be used as a reference for other cement companies.

Thermal insulation of the cyclone of the cement kiln preheating and predecomposition system

The cyclone of the preheating and predecomposition system of a cement company was originally insulated with 114mm refractory bricks and 112mm calcium silicate boards. In order to enhance the heat insulation effect of the refractory lining, the company repaired the cyclone on the east side of Line 3 C5. 25 mm nano-insulation boards were used to replace the original calcium silicate boards of the same thickness, keeping the total thickness of the thermal insulation lining unchanged at 112 mm, and the remaining calcium silicate boards with a thickness of 87 mm were used.

Construction of C5 Cyclone Nano Heat Insulation Board

C5 cyclone insulation lining transformation effect. It was discovered after a period of time that the original calcium silicate board was replaced with nano-insulation board. The heat dissipation loss of the C5 cyclone is reduced by 336W/m2, the shell temperature drops by 21°C, and the heat loss is reduced by 43%. The thermal insulation effect of the refractory lining has been improved.

Improvement of the heat insulation layer in the pre-decomposition zone behind the transition zone of cement rotary kiln

Another cement company’s new special cement line project is to reduce the shell temperature of the rotary kiln’s pre-decomposition zone. In the pre-decomposition zone after the transition zone of the rotary kiln, new nano-insulation panels and grooved brick structures are used to replace the traditional insulation structure. During on-site construction, a 15 mm thick nano-insulation board is inserted into the grooved bricks to form a thermal insulation layer between the rotary kiln shell and the refractory bricks.

Combination form of Rotary Kiln Grooved Bricks and Nano Insulation Panels

The production line uses 15 mm thick nano-insulation panels. Ten days after ignition and production, during normal production of the rotary kiln, the temperature scan of the rotary kiln shell at 35 to 63 m was all green low-temperature areas, and there was no transition color between the two connected areas. It fully reflects the heat insulation effect of the grooved brick composite nano-insulation board. Compared with traditional insulation methods, the surface temperature of the cylinder is reduced by 110°C. The heat dissipation loss is reduced by 4785W/m2, and the annual heat dissipation loss is reduced by 870,000 yuan. The investment can be recovered in about 2 months. Thermal insulation effect of rotary kiln preheat zone.

Regular maintenance and replacement of refractory bricks and thermal insulation lining in the transition zone of the cement rotary kiln

When a cement company was regularly repairing and replacing refractory bricks in two rotary kiln transition zones, it decided to use grooved bricks combined with 15 mm thick nano-insulation panels to reduce the temperature of the shell of the rotary kiln transition zone. After a period of construction, according to theoretical calculations, the shell temperature of the transition zone of the traditional refractory brick rotary kiln can be reduced by 70 to 110°C. It can greatly reduce the ovality deformation of the rotary kiln shell and reduce energy consumption.

Rongsheng Micro-nano Thermal Insulation Board

Rongsheng Kiln Refractory Factory has accumulated rich experience in the application of thermal insulation materials in various industries. In order to reduce the outer wall temperature of high-energy-consuming and high-temperature industrial furnaces and save production costs, micro-nano thermal insulation materials have been introduced. It better meets the needs of the domestic market and solves many domestic and worldwide thermal insulation problems.

Inorganic Thermal Insulating Boards for Cement Rotary Kilns

Nano-thermal insulation material is a nano-scale microporous thermal insulation material produced by using nanotechnology, adding unique anti-infrared radiation materials, and adopting a special process. Compared with traditional micron-sized pore insulation materials such as ceramic fibers and microporous calcium silicate boards, the pores of nano-insulation materials are around 20 nm. The thermal insulation performance at the same temperature is 4 times better than traditional insulation materials.

So far, it has been unanimously proven by many cement companies that the use of nano-insulation materials in the rotary kiln firing system can significantly reduce the heat loss of the rotary kiln barrel. Reducing the kiln operating load and achieving energy saving and consumption reduction are worthy of further research and promotion.

Refractory Material Manufacturers Respond – How to Correctly Choose Refractory Castables?

November 30, 2023 KilnRefractory

Refractory castables are divided into acidic, alkaline, and neutral castables according to their resistance to chemical attack. According to the volume density, it is divided into dense castable refractory and light castable. According to the materials used, it is divided into aluminum silicate, magnesium, magnesium chromium, corundum castables, etc. There are many types of refractory castables, and it is difficult to make a choice without clear indicators and operating temperatures. RS refractory material manufacturer responded to “How to correctly choose refractory castables” and gave some more reliable methods for reference.

(1) Refractory castables must meet the requirements of the kiln’s usage environment.

Dense refractory castables have different requirements depending on where they are used. When selecting, it should be selected according to the characteristics of the castable. For parts that come into contact with high-temperature flames, high-temperature-resistant castables should be selected. Castables with high-temperature resistance and strong penetration resistance should be selected for parts that come into contact with high-temperature solutions. The parts that come into contact with slag should use castables that are highly resistant to the chemical erosion of slag. High-strength and wear-resistant castables are used for parts that come into contact with the impact and friction of various materials. For parts with frequent temperature changes, castables with excellent thermal shock resistance should be used. As long as it meets the requirements of the main production conditions, it is a suitable refractory castable.

The main uses of lightweight refractory castables are heat insulation, reducing load-bearing structures, lowering furnace shell temperature, and reducing heat loss, thereby achieving energy-saving effects.

(2) Economy of investment cost of refractory castables.

After determining which refractory castable to choose, it is also necessary to economically reduce costs. For example, if the use temperature is 1500°C, castables with a use temperature greater than 1600°C will not be selected if the castables can meet the working conditions. If high alumina bauxite clinker is used as the main material in the wear-resistant parts to meet the wear resistance requirements, castables with corundum as the main material should not be selected. The main reason is that the price of refractory castables varies greatly depending on the content of the main materials used. There is no need to ignore economic costs in pursuit of high quality. This requirement is especially important for parts that are subject to daily wear and tear.

(3) Particle size selection of refractory castables.

The construction parts of refractory castables may be thick or thin, and the particle size ratios used are different. For example, when pouring a lining with a thickness greater than 100mm, more large-grained critical aggregates need to be added to improve structural strength and wear resistance. The parts with a thickness of 10mm when poured or painted have fewer large particles of aggregate. Avoid adding large aggregates to make them protrude from the lining, which not only affects the appearance but also causes large particles to wear easily in terms of use. This causes holes in the lining, which in turn affects the service life. Depending on the pouring thickness, the pouring method or the smearing method can be used. Therefore, the selection of particle size of refractory castables is also very important.

(4) The shelf life of refractory castables.

The storage time of refractory castables in dry areas is about 6-9 months. Before use, check whether there are any agglomerations. During transportation or handling, the castable will agglomerate due to extrusion. If it can be easily patted away, the use effect will not be affected. However, the shelf life of the castables is a secondary consideration, because the configuration processes of the castables are different and most parts are not in stock. All need to be produced according to user needs and the production process adjusted.

It can be seen from the above that the selection of refractory castables is variable and must be used flexibly. To quickly select castables, it is necessary to mention the specific use location, working conditions, use temperature, pouring thickness, and construction method of the castables. The main thing is to find the right method to choose high-quality refractory castables while reducing costs.

Performance Characteristics of Dense Refractory Castables

Dense refractory castable is a construction material used in high-temperature operations. Its main function is to fill and support the furnace while providing oxidation resistance at high temperatures. Dense castables refractory are further divided into aluminate cement castables, chemically bonded refractory castables, clay bonded refractory castables, low cement series refractory castables, self-flowing castables, and new technology refractory castables. The body density is generally around 1800Kg/m³-3500Kg/m³.

Dense refractory castables are generally used for furnace lining, working layer, and permanent layer. According to the use environment, use location, and use requirements, different refractory castables are used to extend the service life of the castables.

High-temperature antioxidant properties. Medium and Dense castables refractory can withstand high temperatures and high oxidation temperatures, and their oxidation resistance is better than other types of castables. Can be used in high-temperature furnaces for a long time.

Reusability. Medium and Dense refractory castables can be reused, reducing environmental pollution and waste of resources.

Density and weight. Medium-Dense castables refractory have a lower density and weight than other types of castables, making them easier to move and fill within the furnace.

chemical composition. The chemical composition of medium and Dense refractory castables can be adjusted according to different requirements to meet different high-temperature environments and application needs.

Stability and reliability. Medium and Dense castables refractory can withstand high temperatures and high oxidation temperatures and maintain stability and reliability over long periods of use.

manufacturing cost. Medium-Dense refractory castables are more expensive to manufacture than other types of castables, but their performance value and cost of use make them a popular high-temperature building material.

RS Kiln Refractory Factory

RS Kiln Refractory Factory can provide high-quality refractory lining materials for high-temperature industrial furnace linings, including various refractory bricks, refractory castables, refractory plastics, etc. If you need to buy Dense castables refractory, Dense refractory bricks for the working lining of high-temperature industrial furnaces. Please contact us. We can provide you with high-quality refractory materials at competitive prices.

How to Use Low Cement Castables Efficiently?

November 9, 2023 KilnRefractory

Low cement castables are widely used in the steel industry because of their advantages such as high density, good fire resistance, and excellent slag resistance. At the same time, low cement castables also have some disadvantages. Such as instantaneous coagulation, delayed hardening instantaneous loss of fluidity, etc. Failure to achieve the construction effect will cause losses to users and cause worse effects. So how to use low cement castables efficiently?

Problems that easily occur during the construction of low cement castables. Since low-cement castables contain various additives, they are easily affected by external influences during construction. Its operating performance and quality are prone to changes over time. The main manifestations of on-site construction include excessive condensation, delayed hardening, and reduced fluidity. In the past, low cement castables have experienced phenomena such as instantaneous setting, delayed hardening, and instantaneous loss of fluidity during construction. RS Kiln Refractory manufacturer found through research that the above problems are related to the construction performance of low cement castable itself.

(1) Condensation too fast and too slow

The setting and hardening process of low-cement castables is caused by hydration bonding and cohesion bonding, or cohesion bonding alone. After the water-reducing agent in the castable is determined, the fluidity of the castable will also vary greatly depending on the amount of pure calcium aluminate cement added. When the addition amount exceeds 9%, the flow value of the castable is lower than 110mm, and the normal construction fluidity of the castable can no longer be guaranteed. This may be due to the excessive amount of pure calcium aluminate cement that accelerates the setting and hardening process of the castable.

The following measures can be taken to solve the aging changes of low cement castables. (1) Double-sealed packaging, especially in the rainy season or when the storage time is long. (2) Choose a dispersant with a strong dispersing ability. (3) Consider adding some newly opened packages of cement during construction and mixing. (4) Use a powerful mixer to mix and control the mixing time. (5) Add an accelerator or retarder to adjust the hardening speed of the castable. (6) In terms of on-site management, prevent moisture absorption during storage.

At present, the most effective way to solve the aging change of low cement castables on site is to add a setting accelerator or retarder to the castables. The accelerators and retarder used, especially the carbonate accelerator and citric acid retarder, are used in small quantities have significant effects, and have no adverse effects on the strength of the castable at all temperatures.

(2) Instantaneous loss of liquidity

Instantaneous loss of fluidity sometimes occurs during castable construction. The analyzed reason should be due to the failure of the water-reducing agent in the castable material or improper operation during construction.

Water reducing agent is a surface active substance. The surface activity of inorganic water-reducing agents is not significant. It mainly increases the zeta potential through chemical adsorption, effectively destroying the flocculation structure between particles. Give full play to the filling effect of micro powder and the lubrication effect of free water to increase fluidity. The anionic group N ionized by the organic water-reducing agent in water has a strong surface activity. Its lipophilic end is adsorbed on the surface of colloidal particles by physical adsorption and enters the fixed adsorption layer. The ζ potential increases in the negative direction, and the oil-repellent ends repel each other to achieve the purpose of dispersion. However, the water-reducing agent easily absorbs the moisture in the castable ingredients during the storage process and causes deliquescence and hydrolysis, which increases the acidity of the castable ingredients. This results in loss of water-reducing effect and instantaneous fluidity loss. Therefore, measures should be taken during the production and storage of castables. For example, use a water-reducing agent with poor hygroscopicity, separate the water-reducing agent from the castable, etc. At the same time, instantaneous fluidity loss may also occur during the construction of high-tech castables, especially when the mixing time is too long. We believe that the reason should be caused by the temperature rise caused by long-term stirring.

In addition, when using low-cement castables, avoid adding too much water. If too much water is added, its performance will decrease and even cause the following hazards:

Reduced intensity. Adding too much water will make the water-cement ratio of low-cement castables too high. This results in a reduction in its strength and reduces the load-bearing capacity and service life of the refractory material.
Decreased slag resistance. Adding too much water to low-cement castables will lead to a decrease in slag resistance. It is susceptible to slag erosion and reduces the service life of refractory materials.
Poor thermal shock performance. Adding too much water to low-cement castables will result in a decrease in the thermal shock properties of the material. It is prone to cracking, peeling and other phenomena, which greatly shortens the service life of the material.
Construction difficulty increases. Adding too much water will result in increased flowability of low cement castables. Problems such as slurry leakage and looseness are prone to occur during construction, which affects the quality of the project.

According to the above content, it is known that adding too much water to low-cement castables will have a serious impact on its performance and service life. During construction, the amount of water added must be strictly followed to ensure the quality and performance of the material.

Before construction and storage, pay attention to moisture-proof and avoid contact with water; when using, control the amount of water added and use additives rationally. Storage and use in strict accordance with the construction instructions will basically enable low-cement castables to effectively exert their advantages in high-temperature industrial furnace linings. Contact RS Kiln Refractory Factory for a free quote and sample of low cement castables.

Effect of Graphite Purity on Finished Magnesia Carbon Bricks

October 17, 2023October 17, 2023 KilnRefractory

Magnesia carbon bricks are produced from two raw materials, magnesium, and carbon, through a series of processes. It has high thermal conductivity and mechanical strength, so it is widely used in high-temperature occasions such as metallurgical smelting and steel smelting. During use, mgo c brick has good wear resistance and fire resistance and can exist stably at high temperatures. This is due to the strict selection of magnesia carbon bricks for paint refractory raw materials. Among them, the influence of graphite purity on the finished magnesia carbon brick cannot be ignored.

Rongsheng High-Quality Magnesia Carbon Bricks

Magnesia Carbon Brick Production Process

Generally, magnesia carbon bricks are unburned bricks made of magnesia and flake graphite with thermosetting resin added as a binding agent, with or without antioxidants. The production process of magnesium carbon bricks is very complex, requiring high-temperature reactions and multiple processes. The most important link is the sintering of the bricks. Bricks form crystals at high temperatures and release a large amount of gases, which have a crucial impact on the quality of sintering. Therefore, strict monitoring and management are required during the production process to ensure product quality and stability.

Graphite has a layered structure, and the atoms in the layer are arranged in a hexagonal arrangement with strong covalent bonds. There are van der Waals forces between layers, which makes it have strong directionality, that is, obvious anisotropy. The layer and the entire surface contain low energy and hardly wet liquid high-temperature slag and molten steel. Graphite has high thermal stability without melting, and ion migration is very limited. It is impossible to recombine the ionic bonding between magnesium oxide in mgo c brick and the covalent bonding of graphite. Therefore, the second binder is needed to form a network structure and obtain greater strength. However, it has free valence bonds at the boundary and can adsorb various substances. Flake graphite has higher oxidation resistance than other carbon products, and this oxidation resistance also improves the wear resistance of magnesia carbon bricks.

The Relationship between Graphite Purity and Magnesia Carbon Bricks

The purity and additional amount of flake graphite play an extremely important impact on the performance of magnesia carbon bricks. Its appropriate addition can effectively inhibit slag from intruding into the refractory structure.

Research shows that mag carbon bricks with a carbon content of 15% have better resistance to slag erosion. The main factors that directly affect the performance and use of magnesia carbon bricks include the fixed carbon content in graphite, graphite particle size, shape, and volatile content. The more added, the more ash will be brought in. The purity of graphite affects the anti-flaking performance and high-temperature flexural strength of magnesium carbon bricks. The main component of ash is silica, followed by alumina and iron oxide. At operating temperatures, silicon oxide and iron oxide are easily reduced and oxidized graphite during use, so they are particularly harmful to mgo c brick. As the carbon content increases, the volume density of magnesia-carbon bricks decreases, the strength at room temperature decreases, and the corrosion resistance index drops sharply. The effect on high-temperature flexural strength is not significant, but the peeling resistance is increased. In short, the appropriate amount of graphite added is related to the type of furnace, different parts used, and respective operating conditions. It is usually determined based on whether the magnesia carbon bricks uses conditions that emphasize corrosion resistance or thermal shock stability, or require high strength or oxidation resistance.

In addition, a large number of studies have shown that graphite purity is directly related to the high-temperature flexural strength of magnesia carbon bricks and the melting loss rate during use. The high-temperature flexural strength of mgo c brick increases with the increase of graphite purity. This is due to the difference in the microstructure of magnesium carbon bricks. Mag carbon bricks made of lower-purity graphite have a larger proportion of coarse pores (diameter 20 μm) after carbonization treatment at 1000°C, and their porosity is also higher than products made of high-purity graphite. This may be related to the high flexibility of high-purity graphite and its easy compression during brick-making. Another point is the local weakening of the structure of mag carbon bricks made with lower-purity graphite. After magnesia-carbon bricks are treated at a high enough temperature (such as 1600°C), the silicate minerals associated with graphite melt into the glass phase and react with magnesia or carbon. The original mineral is corroded, the volume is reduced, the contact area is reduced, and a pore zone is formed around the graphite. As a result, the high-temperature strength of magnesia-carbon bricks decreases with the decrease in graphite purity.

The melting loss rate of magnesia carbon bricks decreases with the increase of graphite purity, especially for graphite with a purity greater than 95%. Research on its mechanism shows that above 1300°C, impurities (SiO2, CaO, Al2O3, Fe2O3, etc.) in magnesia and graphite gather at the interface between the two. Low melting materials are generated, making the magnesia particles easily corroded by the slag and flowing into the slag, thus reducing the erosion resistance. Actual magnesia carbon bricks uses results show that the slag resistance of mag carbon bricks made of graphite containing more than 95% carbon electricity is 0.51 times higher than that of ordinary magnesia-carbon bricks.

The use of high-carbon flake graphite with a carbon content greater than 95% to 96% is an effective technical measure to not only improve the quality of mag carbon bricks but also reduce the cost of brickmaking. If the performance of bricks made from graphite and magnesia of the same grade is used as a benchmark, then switching to high-grade graphite will improve brick performance much more than increasing the grade of magnesia. Under the same process conditions, the performance of bricks made of high-grade graphite and low-grade magnesia raw materials is better than that of bricks made of high-grade magnesia and low-grade graphite raw materials. However, it must be noted that when graphite with higher purity is used, less liquid phase is generated in the brick, and oxygen is easily concentrated into the brick, causing oxidation and decarburization of the graphite. For this reason, antioxidants such as metal Al, Si, Al-Mg alloy, SiC, BN, etc. must be added.

RS Magnesia Carbon Brick Manufacturer

This allows it to be used in the manufacture of various high-temperature furnaces and vessels. For example, high-temperature occasions such as steel smelting furnaces, converters, and large ladles. Compared with traditional refractory materials, magnesia carbon bricks have better mechanical strength and thermal conductivity. Therefore, it has broad application prospects in steel smelting and other fields. Its production process is very complex and requires strict monitoring and management to ensure product quality and stability. RS magnesia carbon brick manufacturer can provide you with high-quality magnesia carbon refractory, as mgo c brick, contact us to get free samples and quotations.

Configuration of Magnesia-Chrome Bricks for Copper Smelting Thermal Kilns

September 21, 2023 KilnRefractory

Magnesia-chrome bricks are the most commonly used refractory bricks in copper smelting thermal kilns. Configuration of magnesia-chromium bricks for copper smelting thermal kilns. In common copper smelting thermal kilns such as top-blown converters, horizontal converters, anode furnaces, flash furnaces, electric furnaces, Kifset furnaces, Ausmet furnaces, reverberatory furnaces, oxygen-rich bottom-blown furnaces, etc. Magnesia chrome bricks are the main configuration.

As the name suggests, magnesia-chrome bricks are made of sintered magnesia and chromium sand according to certain proportion requirements and are shaped and sintered by adding additives. According to their chemical properties, magnesia-chromium bricks are alkaline refractory bricks. It is most widely used in non-ferrous metals, especially copper smelting. Secondly, it is also widely used in cement production.

Magnesia chrome bricks can be roughly divided into six different types according to their production methods. 1) Silicate bonded magnesia chromium brick. 2) Directly combine magnesia chrome bricks. 3) Electrofusion rebonded magnesia chromium brick. 4) Semi-rebonded magnesia-chrome bricks. 5) Fused magnesia chrome bricks. 6) Chemically bonded unburned magnesia chromium bricks. Among them, among the thermal kilns for copper smelting, the most widely used ones are directly bonded magnesia chromium bricks, semi-rebonded magnesia chromium bricks and electrofused rebonded magnesia chromium bricks.

Application of Magnesia Chrome Bricks in Flash Furnace Reaction Tower

Directly bonded magnesia chrome bricks

Directly bonded magnesia-chromium bricks have high-temperature strength, slag resistance, erosion resistance, erosion resistance, corrosion resistance, excellent thermal shock stability and volume stability at 1800°C. Directly combined with the main application parts of magnesia-chromium bricks, the bottom of the top-blown converter, the non-working layer of the furnace wall, and around the horizontal converter barrel. Around the cylinder of the anode furnace, there are the walls of the Kifset furnace, the walls of the Ausmet furnace, the top and walls of the reverberatory furnace, and the upper part of the oxygen-rich bottom-blown slag line.

Electrofusion rebonded magnesia chromium brick

Electric fused rebonded magnesia chromium bricks are made by melting the raw materials using the electric fusion method to make fused magnesia chromium materials, crushing them into a certain particle size, and then mixing, shaping, and sintering them. Combined with the magnesia-chromium brick, it is a fine-grained matrix with evenly distributed pores and micro cracks, and is more sensitive to sudden temperature changes than melting and casting. The high-temperature performance of electrofusion rebonded magnesia chromium bricks is between that of fused cast bricks and directly bonded bricks. The main application part of electrofusion rebonded magnesia-chromium bricks is the working layer of the top-blown converter furnace, which is in direct contact with the copper liquid. Horizontal converter furnace mouth. The mouth of the anode furnace. Flash furnace reaction tower. Electric stove mouth. Kifset furnace bottom working layer. Ausmet furnace furnace wall and furnace bottom. The lower part of the oxygen-rich bottom-blown slag line and the wind eye area.

Semi-rebonded magnesia chrome bricks

Semi-rebonded magnesia-chromium brick refers to a kiln refractory product fired from part of the fused magnesia-chromium sand as raw material. The main mineral composition of semi-rebonded magnesia-chromium bricks is periclase, spinel, and a small amount of silicate. Its thermal shock resistance is better than that of directly bonded magnesia-chromium bricks. The main application parts of semi-rebonded magnesia-chromium bricks are the walls of flash furnace sedimentation tanks. Electric furnace hearth. Ausmet stove. The working layer is at the bottom of the reverberatory furnace and the copper outlet.

In actual applications, reasonable magnesia-chromium brick configuration should be carried out according to the kiln structure and working environment. In addition to the above-mentioned magnesia-chromium bricks, magnesia-chromium unshaped refractory materials such as magnesia-chromium ramming materials, magnesia fillers, and magnesia-chromium castables are also used in copper metallurgical thermal kilns.

Magnesia Chrome Bricks for Flash Furnace Melting Pool

Application advantages of magnesia chrome bricks in copper smelting furnaces

In the development history of magnesia-chromium refractory materials used in the copper smelting industry, silica bricks were first used to build furnace linings. However, since the slag composition contains FeO and SiO2, and the smelting atmosphere contains a lot of SO2 acidic gas, the erosion damage of the silica bricks is very serious. From the 1950s to the 1960s, alkaline bricks have been used in the copper smelting industry. Today, after several generations of continuous improvement, the production process of magnesia-chromium refractory materials and its application in the copper smelting industry is becoming more and more mature.

Currently, direct-bonded magnesia-chromium bricks are widely used in converters. The technology of directly bonding magnesia-chromium bricks to build the furnace body, and using electric fusion and then bonding magnesia-chromium bricks to build the tuyere, furnace mouth, and other positions to build the converter lining has been applied.

Taking the lining construction of a 150t copper converter in a certain factory as an example, ordinary silicate-bonded magnesia-chromium bricks are used to build the cylinder and end wall linings. Directly bonded magnesia-chromium bricks with high chromium content have been used in locations such as tuyere slag lines that are severely corroded, and good results have been achieved.

A copper factory also achieved good results by using improved electric fusion combined with magnesia-chromium bricks to build tuyere, extending the furnace life and reducing the period of minor repairs.

Generally speaking, ordinary magnesia-chromium bricks are currently used to build furnace linings. The general method of constructing the copper converter lining is to use directly bonded bricks or electro-fused rebonded magnesia-chromium bricks to build the tuyere, slag line, furnace mouth, and other locations.

What are the Advantages of Applying Ceramic Fiberboard to Industrial Furnaces?

September 6, 2023 KilnRefractory

The main raw material of ceramic fiberboard is aluminum silicate, which is one of the important guarantee factors for the kiln to save energy, reduce consumption, and optimize high production. According to the temperature division, fiberboard can be widely used in the backing of industrial kilns or the hot surface of low-temperature kilns. If you want to ask, what advantages does ceramic fiberboard have in industrial furnaces? Then its advantages are still obvious.

The specific heat capacity (storage heat) is small. One of the reasons why ceramic fiberboard can reduce the maintenance cost of industrial kilns is its small specific heat capacity, which can save energy during the shutdown and start-up of the heating furnace.
Low thermal conductivity. The ceramic fiberboard furnace lining has low thermal conductivity and a good heat insulation effect.
Good thermal shock resistance. The porosity of the ceramic fiber board is high, and the ceramic fiber lining can meet various rates of heating or cooling without damage (under the premise that the kiln body can bear it).
Good sound insulation performance. Ceramic fiber board has good sound insulation ability, can reduce noise pollution, can be used as sound insulation material, and can also be used as wall insulation and sound insulation material in buildings (such as structural insulation integrated ceramic wool composite insulation board).
Stable chemical properties. The main chemical composition of ceramic fiberboard is aluminum silicate, which does not easy to be corroded except for the reaction with strong acids and alkalis.
Wide application range. Refractory ceramic fiberboard can meet the requirements of different operating temperature ranges (such as between 600°C and 1300°C). Different industrial furnaces that can be applied to different industries require the use of refractory ceramic fiber boards.

What is the Insulation Effect of Ceramic Fiberboard?

What kind of insulation effect does the ceramic fiber board play? Ceramic fiber board is also called ceramic cotton board, which has good characteristics of high-temperature resistance, heat preservation, and heat insulation, and is widely used. Ceramic fiber boards can be used for the lining of highly heat-sensitive furnaces. So what is the so-called high heat-sensitive stove?

The so-called high heat sensitive furnace means that the furnace can effectively control the heating or cooling speed. In contrast, what is thermal inertia? This means that when the furnace is heated, the heat is almost absorbed by the furnace lining, the furnace temperature is almost synchronized with the furnace wall temperature, and the heat rises slowly. When cooling, almost all the heat is from the furnace wall, and the furnace temperature drops slowly. If the cooling or heating time is too long, it will waste a lot of fuel, and reduce production efficiency and product quality.

The lining material determines how to increase the heat sensitivity of the furnace.

Different from the traditional refractory brick lining, ceramic fiber boards can effectively improve this problem. The ceramic fiber material has a low thermal conductivity and hardly absorbs the heat of the furnace, effectively reducing heat loss and shortening the heating time. When the temperature is lowered, the heat storage capacity of the furnace is reduced, and the heat sensitivity of the furnace is increased.

RS High-Quality Ceramic Fiber Insulation Board

Application of Ceramic Fiber Products in the Steel Industry

The refractory lining of traditional industrial kilns has a large weight, the waste of heat storage in the furnace body is serious, and the heat preservation effect is poor. The temperature of the cold surface of the furnace body exceeds 100°C, and it is difficult to precisely control the temperature of the furnace. In recent years, the ceramic fiber module refractory lining of the furnace wall and roof of the industrial furnace has been designed with a full fiber lining. Due to the low thermal conductivity, low density, and light weight of fibers, lighter steel frame support structures are used in the design and construction of kilns. As a result, the development of industrial furnaces has entered the era of “kiln lightweight”. The heat storage of fibers is small, which is suitable for the operation mode of rapid heating and cooling. In addition, the ceramic fiber module can be processed into special-shaped products to adapt to various shapes of the inner wall of the furnace shell. The fiber module has good resistance to mechanical vibration and shock and has good chemical stability. These advantages have played an important role in promoting the development of new kilns.

Taking heating furnaces in the steel industry as an example, ceramic fiber modules are mainly used for ladle covers, billet carriers, furnace walls of heat treatment furnaces, etc. At present, a large number of ceramic fiber modules are used as linings in heat treatment furnaces that require high furnace cleanliness. In the annealing furnace for cold-rolled strip steel, from the heating section to the cooling section, from the top to the bottom of the furnace, ceramic fiber modules are used as linings. In the direct fire heating part of the preheating section, the hollow module is convenient for direct installation of the burner. On the furnace wall of the heating section, in order to cooperate with the installation of the radiant tube, the entire furnace wall module adopts the form of B, and at the journal of the furnace roller, the module can be made into a bell shape. Very convenient for furnace lining installation. In order to prevent fiber shedding from polluting the steel strip, aluminum cloth can also be sewn on the module as an inner lining. Special-shaped modules can be used in some special-shaped parts such as the furnace throat and the bottom chamber.

The good thermal insulation performance of the ceramic fiber module makes it widely used in the thermal insulation layer of high-temperature industrial furnaces. RS Kiln Refractory Material Manufacturer is a powerful refractory material manufacturer. Our refractory products have been sold to more than 100 countries and regions all over the world. Moreover, our technical team is committed to the R&D, design, and construction of refractory materials for the insulation layer. Our new thermal insulation material products can achieve a body density of less than 0.4g/cm3. Contact us for free samples and quotes.

Sintered Corundum Brick for Glass Furnaces

July 10, 2023 KilnRefractory

What is the material of sintered corundum brick? Sintered corundum bricks are refractory products made of sintered dense alumina clinker. The brick has the characteristics of a high melting point, stable performance at high temperatures, good mechanical strength, and wear resistance. Sintered corundum bricks have excellent resistance to metal corrosion, oxidation, and reduction. 99 high aluminum content sintered corundum bricks, zirconium corundum bricks, high refractoriness, used in chemical solid waste incinerators. The raw material for making sintered corundum bricks is calcined and finely ground high-purity industrial alumina, and sometimes a small amount of MgO additive is added to improve the crystal structure. Sintered corundum brick for glass furnaces – RS kiln refractory brick manufacturer.

Sintered Corundum Brick for Refining Furnaces — Sintered Corundum Bricks

90 Alumina High-Strength Sintered Corundum Refractory Brick

Corundum brick 90 alumina, high-strength sintered corundum refractory brick, stable performance at high temperatures. Re-sintering fused corundum bricks, the manufacturing process includes pressing the raw materials into green bodies, and then calcination at a high temperature above 1850 °C. Calcination reduces the porosity in the green body structure, increases the crystal grains by about 25-40 times, and forms a dense plate-like structure. When making bricks, the sintered corundum with a porosity of less than 3% and a bulk density greater than 3.60g/cm3 is crushed to the required particle size. The main chemical components of sintered corundum bricks include Al2O3, SiO2, Fe2O3, CaO, MgO, Na2O, etc. The physical and chemical properties of sintered corundum bricks include purity, refractoriness, apparent porosity, bulk density, compressive strength, creep rate, load softening temperature, etc. The production process involves crushing sintered corundum into coarse particles and fine powder. A small amount of clay or other binders are added for kneading, shaped by a high-pressure friction brick press or hydraulic press, and then dried and fired. Sintered corundum bricks are widely used in blast furnaces and refining furnaces in the metallurgical industry, as well as in chemical, electronic, and other industrial fields.

Corundum Sintered Refractory Bricks, High-Purity Low-Silicon Corundum Bricks, Source Manufacturers

Sintered corundum brick has stable performance at high temperatures, and high melting points, and the normal temperature compressive strength of corundum brick can reach 340MPa. The load softening start temperature is greater than 1700°C. It has strong resistance to acidic or alkaline slag, metal, and glass liquid. Corundum sintered refractory bricks, high-purity low-silicon corundum bricks, Rongsheng manufacturers, direct delivery.

Sintered corundum bricks are fired at high temperatures in a shuttle kiln. It has the characteristics of high refractoriness, good thermal shock stability, high-temperature strength, strong slag resistance, small expansion coefficient, low creep, and spalling resistance. The thermal shock stability of corundum bricks is related to their structure, good corrosion resistance, but poor thermal shock stability. The bulk density is greater than 3.60g/cm3, and the porosity is less than 3%.

Sintered corundum bricks are high-grade refractory materials, suitable for use in high-temperature kilns under various atmospheric conditions. High-quality high-purity corundum bricks are widely used in high-temperature sintering of zirconia ceramics, fluorescent materials, electronic ceramics, magnetic materials, ceramic powders, and gasifiers in the petrochemical industry. Synthetic ammonia secondary conversion furnace, carbon black reaction furnace and glass industry high-temperature kiln, and other equipment. The dimensions, physical and chemical indicators, and service life of the products have met the requirements of high-temperature furnaces.

The production process of sintered corundum bricks is to crush sintered corundum to 3mm coarse particles and some fine powders less than 0.074mm in height. Some add a small amount of clay and other binders for mixing and shape them with a high-pressure friction brick press or hydraulic press. The adobe is fired in a high-temperature chamber after being dried. Generally, the sintered corundum brick with higher purity has a firing temperature of 1750-1800°C.

Sintered corundum bricks have good high-temperature resistance, good corrosion resistance, and thermal shock stability. Rongsheng sintered corundum bricks are mainly used in blast furnaces and refining furnaces outside the metallurgical industry. It is also used in ironmaking blast furnaces and blast furnace hot blast stoves, refining furnaces outside steelmaking furnaces, sliding nozzles, glass melting furnaces, and petrochemical industrial furnaces. Now on the market, the proportion used in glass melting furnaces is more.

Sintered Corundum Bricks Have High Compressive Strength and Corrosion Resistance

Sintered corundum bricks refer to corundum refractory products with an alumina content greater than 90% and made from sintered alumina clinker. Refractory bricks, sintered corundum bricks, corundum bricks, high compressive strength, and corrosion resistance. Gas-bonded corundum brick has a high melting point and stable performance at high temperatures. It has good mechanical strength and wear resistance at room temperature and high temperature, and has excellent resistance to metal corrosion and redox.

Sintered Corundum Brick from Rongsheng Referactory Manufacturer — Sintered Corundum Brick from Rongsheng Refractory Manufacturer

The production process of sintered corundum bricks is to crush sintered corundum to 3mm coarse particles and some fine powders smaller than 0.074mm. Some add a small amount of clay and other binders for mixing. It is shaped by a high-pressure friction brick press or hydraulic press, and the adobe is fired in a high-temperature chamber after drying. Generally, the sintered corundum brick with higher purity has a firing temperature of 1750-1800°C. If a small amount of clay or additives is added, the firing temperature can be 1600~1700°C.

Sintered corundum bricks have been widely used as lining materials in petrochemical thermal equipment with high temperatures, high pressure, severe chemical erosion, and mechanical wear. With the advancement of production technology in the petrochemical industry, many new processes and technologies have been adopted in production, in order to make the equipment achieve the purpose of large load, long cycle, low energy consumption, and low cost. In addition to the transformation of various thermal equipment, higher requirements are also put forward for the lining materials of various thermal equipment.

However, the raw materials of corundum bricks are all high-end products, and the price of sintered corundum bricks is also a high-end product among refractory products. Therefore, the price will naturally be much higher than ordinary refractory materials.