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Thermal Insulation Acid Resistant Refractory Castable for High Temperature Chimney

July 2, 2022 by rsrefractorycastable

Lightweight Thermal Insulation acid-resistant refractory castables are usually used for the lining of the chimney wall of the circulating fluidized bed boiler. On the lining of the chimney wall of the circulating fluidized bed boiler, the castable is used not only as an acid-resistant lining, but also as a refractory and heat-insulating layer, and no insulation layer is added.

The light acid-resistant castable is composed of light aggregate, powder, binder, and additives, and the main component of the binder is water glass. The lightweight aggregate structure has a large porosity, a rough surface, and a particle size of about 5mm, and the aggregate and powder have high water absorption and hygroscopicity.

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Lightweight acid-resistant castables have the characteristics of low bulk density, fast solidification, high service temperature, increased compressive strength with the increase of temperature and acidity, small thermal conductivity, and a small coefficient of linear expansion. However, lightweight Thermal Insulation acid-resistant castables have relatively high requirements for transportation and storage. This is because the manufacturer has prepared the aggregate and powder into a mixture when leaving the factory, and then packed it in a woven bag. When transported to the site, it needs to be temporarily stored in a warehouse with good drainage measures, rain-proof, moisture-proof, and dry.

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Features of Lightweight Thermal Insulation Acid-Resistant Castables

Lightweight Thermal Insulation acid-resistant castables are unshaped refractories that can be directly cast into linings as needed, and can also be made into prefabricated bricks.

Lightweight heat-insulating acid-resistant castables have the characteristics of high compressive strength, acid and acid gas corrosion resistance, light volume, and low water absorption. Thermal Insulation acid-resistant refractory castables fully play a role in thermal insulation in tall chimneys, high-temperature flues, and pipe linings. The light acid-resistant castable can ensure the compactness of the masonry when it is used in places with severe acid corrosion. It can also be used in acid-resistant projects such as acid-resistant pools and tanks in petroleum, chemical, non-ferrous metallurgy, and other industries.

Lightweight Thermal Insulation acid-resistant castables are easy to construct, have strong cohesion, and have a long initial setting time and construction operation time. The strength of the castable increases rapidly, the impermeability is strong, and no acid treatment is required. It is convenient to ensure the dense and full masonry ash joints, and can significantly improve the air tightness and integrity of the chimney lining wall and the anti-corrosion ability of the lining.

Lightweight Thermal Insulationacid-resistant castables need to be poured in layers, and the layered vibrating time should be shorter than the vibrating time of the castable. The amount of water added to the castable also needs to be strictly controlled, and the amount of water determines the performance and strength of the castable. Therefore, attention must be paid to the construction of the castable, and the mixed water should be added according to the construction standards of the castable.

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Matters needing attention in the construction of light acid-resistant castables

In the construction of castables, it is necessary to choose a more suitable construction environment, and a suitable temperature is a key to the construction of refractory materials. How much should the construction temperature of acid-resistant castables be controlled? Let’s find out together.

In the preparation of lightweight thermal insulation and acid-resistant castables, the main raw materials used are aluminate cement and light aggregates. Raw materials such as perlite aggregates are made by adding various additives such as high alumina fine powder and silicon powder. The product has the characteristics of light volume, high compressive strength, alkali resistance, acid gas resistance, heat insulation, heat preservation, and low water absorption. The lightweight Thermal Insulation acid-resistant refractory castable has the characteristics of convenient construction and convenient construction in the preparation process and is an ideal product for the construction of high-temperature acid-resistant components.

After talking about the characteristics of so many lightweight Thermal Insulation acid-resistant refractory castables, according to the structural characteristics of acid-resistant castables, what temperature should the construction temperature be controlled at? In the construction of castables, the construction temperature can be flexibly selected according to seasonal changes. In the summer construction environment, the construction temperature is about 20 to 30 ℃. When the temperature is too high in summer, the setting speed of the acid-resistant castable will be accelerated, but the strength of the castable will be affected. When the castable is prepared, a small amount of retarder can be added to slow down the setting process of the castable. In the winter construction environment, the construction temperature should be between 5°C and 10°C at room temperature, and the construction temperature should not be lower than 0°C. When the temperature is too low, an accelerator needs to be added to accelerate the setting of the castable.

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Thermal Insulation Acid Resistant Refractory Castable for High-Temperature Chimney Wall Lining. High-quality lightweight heat-insulating acid-resistant refractory castables, free samples, and quotations, please contact us.

Industrial Kiln Insulation Refractory Castable for Sale

June 10, 2022 by rsrefractorycastable

With the development trend of the integration of the global economy, resources, and environment, industrial kiln technology and equipment level are facing great challenges, and it is imperative to save energy and reduce emissions. Therefore, the development of industrial kilns must take a sustainable development path with high technological content, good economic benefits, low resource consumption, and less environmental pollution. Therefore, more and more industrial kilns now put forward higher requirements on the thermal insulation layer of the kiln body. This is also a great challenge for refractory manufacturers. Rongsheng refractory castable material manufacturer, through years of accumulated experience in the use of industrial kiln lining refractory materials, is more careful and perfect in the configuration and design of materials for the thermal insulation layer of industrial kilns. Rongsheng has made greater breakthroughs in the production of unshaped monolithic refractory castables for industrial kilns. Industrial Kiln Insulation Refractory Castable for Sale, contact Rongsheng for free samples and prices.

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Industrial Kiln Insulation Refractory Castable for Sale

The design of the thermal insulation layer of the industrial kiln slows down the loss of temperature in the kiln, reduces thermal energy consumption, and saves fuel costs. On the one hand, it ensures the safety of production, and on the other hand, it is of great help to save production costs and prolonging the operating life of kiln furnace equipment. So, how is the thermal insulation layer of industrial kilns generally designed?

In the design of the thermal insulation layer of industrial kilns, the materials generally used are ceramic fiber products, thermal insulation bricks, and thermal insulation refractory castables. These materials, according to the different working conditions of different industrial kilns, choose different materials of thermal insulation bricks and thermal insulation refractory castables for industrial kilns and configure different indicators.

Insulation refractory castable is also called lightweight refractory castable, thermal insulation refractory castable. The Industrial Kiln Insulation Refractory Castable is mainly composed of light thermal insulation aggregate, added with refractory powder, together with bonding material and admixture. A hydraulic unshaped thermal insulation material is prepared by dry mixing according to the optimum ratio. It has the characteristics of low bulk density, low thermal conductivity, and high thermal insulation performance, and can be constructed and poured on-site. Lightweight refractory castables, also known as lightweight insulating castables, are widely used in the thermal insulation layer of boilers, industrial kilns, and other equipment bodies. It is mainly used for heat preservation of kiln and to prevent the loss of heat energy.

Industrial Kiln Insulation Refractory Castables for Sale in Rongsheng — Industrial Kiln Insulation Refractory Castables for Sale

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Classification of Industrial Kiln Insulation Refractory Castables

Insulation castables are used for boiler linings and are generally used as insulation linings. The use temperature is generally under 1000 ℃. Thermal insulation refractory castables are classified into the following three categories according to the operating temperature.

Low-temperature lightweight castable, the operating temperature is 600℃-900℃.
Medium temperature light castable, the operating temperature is 900℃-1200℃.
High-temperature lightweight castable, the operating temperature is >1200℃.

Lightweight castables with bulk densities of 0.8 and 1.0 are common for thermal insulation castables. Lightweight castables with a bulk density of 0.8 or 1.0 can also be used for thermal insulation refractory castables for industrial kilns. In the refractory industry, thermal insulation castables can also be divided into 3 categories according to their bulk density.

Semi-light castable (1.0-1.8 g/cm3)
Lightweight castable (0.4-1.0 g/cm3)
Ultra-light castable (less than 0.4g/cm3)

Industrial Kiln Insulation Refractory Castables Construction

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Properties of thermal insulation castables for industrial kilns

The selection of the thermal insulation layer lining of the industrial kiln generally refers to the operating temperature and thermal conductivity. In the end, it is necessary to select an insulating castable with a suitable bulk density. The smaller the bulk density of the Industrial Kiln Insulation Refractory Castables, the smaller the thermal conductivity, and the better the thermal insulation performance. During the production of thermal insulation castables, high-index thermal insulation castables can also be customized according to requirements. Insulation castables of different materials are used in thermal insulation layers of boilers and high-temperature kilns at different temperatures.

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Buy High-Quality Insulation Castables for Industrial Kilns

Rongsheng refractory castable factory can provide unshaped monolithic refractory castables for thermal insulation layers for various industrial kilns. Moreover, Rongsheng Environmental’s advanced monolithic refractory castable production line provides a production guarantee for refractory castables of various raw materials used in industrial kilns. Please use it in strict accordance with the construction and storage instructions of the unshaped refractory materials when you use the unshaped refractory castable. The quality of our monolithic refractory castables products is guaranteed, and our perfect after-sales service system can also provide reliable solutions for your refractory lining problems. To purchase high-quality Insulation Castables for Industrial Kilns, please contact us.

The Differences Between the Three Different Monolithic Refractories

April 19, 2022 by rsrefractorycastable

Refractory mortar, refractory cement, and refractory castables are all monolithic refractories, and they are commonly used in the refractory industry. So, what are the differences between these three different monolithic refractories? Simply put, refractory mortar is used for masonry refractory bricks. Therefore, refractory mortar is also known as refractory mortar or joint compound. Refractory cement is one of the materials for making refractory concrete and is generally used as a binder. Refractory castables are sometimes referred to as refractory concrete. It is made of refractory aggregates, powders, and binders, and is also called refractory castables because of its pouring construction.

The Difference Between Three Different Amorphous Refractories

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Refractory Mortar

Refractory mortar can be divided into fireclay, high alumina, silica, and magnesia refractory mortar according to the material. It is composed of refractory powder, binder, and admixture. The general refractory mortar is made of refractory clinker powder and an appropriate amount of plastic clay as a binder and plasticizer. Its normal temperature strength is low, and it has high strength only when it constitutes a ceramic bond at a high temperature. The particle size of refractory mortar varies according to the application requirements, and its limit particle size is generally less than 1mm, and some are less than 0.5mm or finer.

The material of refractory mortar should be considered together with the material of masonry refractory products. In addition to being used as a joint material, refractory mortar can also be used as a maintenance coating for the lining body by the modification method or the spray method.

refractory castable cement — High-Temperature Refractory Cement

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Refractory Cement

Refractory cement is also called aluminate cement. Aluminate cement is a hydraulic cementitious material obtained by calcining bauxite and limestone as raw materials, clinker with calcium aluminate as the main component and alumina content of about 50%, and then grinding. Aluminate cement is often yellow or brown, but also gray. For the lining of industrial kilns.

Refractory Castables (Refractory Concrete)

What is refractory concrete? What is refractory concrete composed of? Refractory concrete is composed of refractory aggregate, refractory powder, and cement or admixture in a certain proportion. After stirring (the cement should be mixed with appropriate water), molding and curing, it can be used directly. Generally, it is also called refractory castable.

Refractory castable is a kind of monolithic refractory that is widely produced and used. It is mainly used to construct the overall structure such as the lining of various heating furnaces. Certain high-quality varieties can also be used in smelting furnaces. For example, aluminate cement refractory castables can be widely used in various heating furnaces and other thermal equipment without slag and acid and alkali corrosion. The parts that are corroded by molten iron, molten steel, and slag have a high working temperature, such as tapping groove, ladle and blast furnace shaft, tapping ditch, etc. In some parts of metallurgical furnaces and other vessels that are in direct contact with slag and molten metal, repairing with high-quality phosphate refractory castables also has excellent results.

castable refractory concrete — High-Alumina Castables Refractory

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Refractory concrete can generally be divided into two categories, shaped refractory products, and bulk refractory materials.

Shaped refractory products. Including prefabricated components, prefabricated blocks (unit weight less than 30 kg), and unburned bricks produced by vibration, machine pressing, ramming, and vibration pressing. Such products are generally factory-produced, with stable quality, regular size, and less template consumption.
Bulk refractory materials. Including refractory aggregate, refractory powder, cement, etc., as well as the mixture of the above-mentioned several raw materials in proportion, and leaves the factory in bulk form. During construction, appropriate water or liquid binder should be added to the bulk material, which can be formed by any method.

An important feature of refractory concrete is that it does not require pre-calcination, and can be used to directly build a furnace, or it can be assembled with prefabricated components and used after baking. Therefore, refractory concrete has many advantages over fired refractory bricks.

Advantages of Refractory Concrete

The production process of refractory castable concrete is simple, usually, only construction equipment such as concrete mixers and vibrators are used, and there is no need for huge brick presses and firing equipment. Therefore, the construction of refractory concrete plants requires less investment, a quick start, and great results. And it can save a lot of fuel and electricity, the production cycle is short, and the production efficiency is high.
The refractory concrete is easy to construct and manufacture, can be arbitrarily shaped and can meet the various requirements of production for thermal equipment. Some special parts of thermal equipment are difficult to be made of fired bricks, and refractory concrete can be used. In addition, refractory concrete can be made into a composite lining that is light and heavy. This reduces the thickness and reduces the overall weight of the kiln. It not only saves materials and fuel but also uses less steel. Refractory concrete can also be equipped with a small number of steel bars, which are both used as linings and load-bearing. The steel envelope can be partially or completely removed.
In addition to the commonly used vibration molding process, refractory concrete can also be constructed by various process methods such as spraying, ramming, or machine pressing according to engineering characteristics and production needs. Suitable for new construction, renovation, and hot and cold repair of furnaces and thermal equipment. Especially when using prefabricated components and spraying, the furnace construction can be mechanized, greatly shortening the construction period and speeding up production and construction. In the process of kiln and thermal equipment production, the damaged prefabricated components can be replaced without stopping, and the furnace lining can be thermally repaired by spraying a new process, thereby improving the operation rate of the kiln.
Kilns and thermal equipment made of refractory concrete have strong integrity and good airtightness. The reasonable application can increase its service life by 30~150%, and some are as high as 8~5 times. This not only improves the operation rate but also reduces the consumption of refractory materials and saves the cost of building the furnace.
The raw materials used in refractory concrete, in addition to the raw materials for making bricks, can also use some industrial slag, waste refractory bricks, and local or natural materials. That is to say, it uses a wide range of materials, which is convenient for comprehensive utilization of resources, and opens up a broadway for the refractory industry.
The production and construction of refractory concrete furnaces have good working conditions, low labor intensity, and high efficiency. Furnace builders can get rid of the tile knife, creating conditions for the realization of mechanized furnace construction.

From the above, we can see that although the three products are all monolithic refractories, their uses are quite different. And each product is divided into different models and types. Therefore, when purchasing, you can consult professional technicians and choose suitable products, so as not to delay the construction period and cause unnecessary losses.

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In a word, the development and adoption of new refractory concrete materials can promote the technological innovation of refractory production and kiln structure, save fuel, power, financial resources, and manpower, and realize mechanization of production and construction. Achieve the purpose of prolonging the life of the kiln, reducing the consumption of materials, and increasing production. Therefore, refractory concrete is a new type of refractory material with broad development prospects. Rongsheng refractory manufacturer has rich experience in the production and design of various unshaped refractory materials. Provides high-quality, long-life refractory lining materials for a variety of furnace types. Rongsheng refractory manufacturer will become your best choice for purchasing unshaped refractory materials.

Refractory Mud VS Refractory Cement?

November 23, 2021 by rsrefractorycastable

High alumina refractory mud is different from high alumina cement.

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The difference between them is: high alumina refractory clay is a refractory material used in the joints of refractory bricks, and the sheet material is high aluminum powder plus a certain proportion of binding agent and coagulant. After adding water or adding liquid binder, stir it into a slurry, and apply it on the surface of the refractory brick to adjust the size deviation. It can make the refractory bricks form a tight whole to prevent the damage of high temperature and external force. In other words, it is the fire clay for bricklaying. It is a finished solid powder.

High alumina cement is a kind of binder in the application of refractories. High alumina cement is also called aluminate cement. It is clinker with 50% alumina content calcined with bauxite and lime. Aluminate cement is yellow or Brown, high grade high alumina cement is white. The labels are 625#, 725#, 925# and CA70, CA80.

High alumina cement is closely related to refractory materials and can be used as a binder for various castables. In addition, some 525# and 425# refractory cements are equipped with gypsum bauxite for construction and special projects. High alumina cement has a good coagulation effect in the castable, which will make the castable have high temperature resistance and good strength. It is a raw material for refractory materials.

The high alumina refractory clay cement is also divided into multiple grades, and is used for building a variety of multi-material refractory bricks. It is divided into high alumina refractory mud and phosphoric acid refractory mud.

Although both high alumina refractory mud and high alumina cement are powdered materials, there is a big difference between high-alumina refractory mud and high alumina cement. High alumina refractory mud is processed into powder with high-alumina particles smaller than 180 mesh, plus some binders. , A synthetic material made of coagulant. The high alumina cement is the finished material after calcining bauxite and lime.

Therefore, high alumina cement and high alumina refractory mud are completely different products, but they are closely related to refractory materials. It is also one of two varieties with a large proportion among refractory products.

What is the Damage Form of the Refractory Castable for Ladle?

July 31, 2021 by rsrefractorycastable

The castable for ladle, in terms of material, was originally based on “Zirconia-Silicon” stone. However, with the requirement of clean steel and the increase of secondary refining, the high-durability alumina spinel is gradually adopted. During this period, tests were also done on magnesia-based alkaline materials, but they were not put into practical use due to the inability to suppress structural peeling. Therefore, in terms of extending the service life of the ladle, understanding the damage mechanism of the castable for the ladle is a very important link. Refractory manufacturers and steel mill customers have conducted a series of studies on the damage pattern of the castable for ladle.

Steel Ladle Working Conditions — Steel Ladle

The Damaged Appearance of Castable for Ladle

Regardless of shaped or unshaped refractories for ladle, the slag line, molten steel parts, and the bottom of the ladle will be damaged to varying degrees.

Damage to the slag line

At the position equivalent to the “slag-steel” interface, the damaged surface is smooth and deep with a clear outline. The reason for making it smooth is that the damage is mainly corrosion, but there are also cracks. Recently, due to the use of alumina spinel castables, satisfactory durability has not been obtained. Therefore, magnesia carbon bricks are mostly used. The damage rate is 1~2mm/furnace, and it needs to be repaired after about 100 furnaces are poured.

Damage to the molten steel

The corrosion damage is very small under the current materials and uses conditions, and the cracks and the peeling caused by their expansion are the main damages. Repeated peeling affects the life span. On average, the damage rate of “zirconium-silica” stone is 1 mm/furnace, and alumina spinel is 0.3~0.5mm/furnace. Now the most durable alumina spinel has a life span of 250 to 300 furnaces. Since the molten steel part is the main part that determines the life of the ladle, the damage of this part needs to be paid attention to.

The bottom of the package is damaged by the steel part

Due to the impact of molten steel, the steel parts during pouring steel wear and then develop into cracks, where molten steel penetrates to affect the service life. Use alumina castable prefabricated block, which needs to be repaired after about 100 times of pouring.

Damage Patterns of Refractory Materials for Ladle

The characteristics of the damage of the castable are that although there is no damage to the brick joints, cracks of varying sizes and seldom occur hot spalling instead. The damage of ladle castables is also the same as before, which can be divided into the following three aspects.

Corrosion, continuous loss caused by surface or internal melting.
Mechanical wear, loss caused by the impact of molten steel, etc.
Spalling, falling of refractory lining caused by high temperature, machinery, structure, etc.

Alumina Spinel Castable for Steel Ladle — a Kind of the Alumina Spinel Castable from RS Factory

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It is rare that corrosion is the main factor in molten steel. At the part of the molten steel where the working face is spalled in layers, the structural spalling caused by slag penetration, that is, the cracking caused by the structural thermal stress is the main cause of damage. However, for alkaline materials and some alumina spinel castables, cracks also occurred in the original layer, and thermal spalling occurred, mainly due to the cracks caused by the concentration of thermal stress.

The temperature of molten steel, the composition of slag, and the residence time of molten steel have a great influence on the damage of refractory materials. After discovering the damage of the refractory layer of the ladle, the analysis of the related damage mechanism will be of great help to prolong the service life of the ladle. To purchase refractory castable for ladle, please contact the refractory castable manufacturer.

Two Questions and Answers about Refractory Castables Used in Furnace Lining

June 16, 2021June 10, 2021 by rsrefractorycastable

With the increase in the use temperature and service life of various high-temperature kilns and thermal equipment, refractory castables are widely used in production and use as unshaped refractory materials. In the modern era of rapid industrial technology, there are many types of refractory castables. Compared with refractory bricks, the advantages of using refractory castables are simple to process, energy-saving, low cost, and easy mechanized construction. It has been widely used in various types of thermal equipment such as cement, steel, glass, and electric power. As a result, the use of refractory castables in high-temperature kilns often encounters some problems. Experienced unshaped refractory castable manufacturers will take you to understand these problems and provide you with the most suitable refractory castable lining solution for your production needs.

Question 1: The operating temperature of the kiln is 1500℃, what refractory castable should be used?

When the temperature of the working part of the kiln is 1500℃, corundum castable should be selected according to the use temperature of the refractory castable. Many users do not understand but think that the price is high, so they choose general high-aluminum castables.

However, if the direct use temperature is 1500°C, the general high-aluminum castable is not acceptable. The brown corundum castable must be selected to meet the application requirements. There are also users who propose to use steel fiber castables, which is not acceptable. Because steel fibers begin to melt at temperatures above 1300°C. Therefore, steel fiber castables cannot be used.

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However, some customers choose to use stainless steel. The answer given by refractory manufacturers is still no. Because the stainless steel used for the lining only serves as an anchor, it cannot resist high temperature and corrosion. The characteristics of corundum castable are the highest bulk density, lowest apparent porosity, high-temperature resistance, corrosion resistance, and thermal shock resistance. And at 1500℃, the characteristics of corundum castable can be fully reflected. If steel fiber castable is used, it cannot withstand the high temperature of 1500℃. The general high-aluminum castables can be used at a temperature of 1300℃-1400℃.

Refractory castable manufacturers pointed out that if it is a different kiln, the working atmosphere inside the kiln is different and the degree of erosion is different, corundum wear-resistant castable or high-strength wear-resistant castable can also be selected. In this way, it is resistant to both high temperature and corrosion. For example, waste incinerators have low temperatures, but strong corrosion, sometimes with acid and alkali corrosion. At this time, the choice of corundum castable is not acceptable, the temperature is not high, and the corundum cannot be fully used. Wear-resistant castables with clean raw materials can be used to resist acid or alkali corrosion. Moreover, the price is lower than that of corundum castable, and it is also suitable for the special use of incinerators.

In short, no matter what kind of refractory castable is selected, the appropriate refractory castable must be selected according to different kilns, different temperatures, and different degrees of erosion.

Question 2: How much is a ton of corundum steel fiber refractory castable for the rotary kiln?

Corundum steel fiber refractory castable is a high-quality refractory castable. It uses special grade bauxite clinker and sintered corundum as refractory aggregates and admixtures, and calcium aluminate cement as a binder. Unshaped refractory material mixed with a small amount of water reducing agent and a certain proportion of wear-resistant and heat-resistant steel fibers of different sizes and diameters using micro-powder technology. It is castable with good fluidity, high strength, good wear resistance, and good thermal shock resistance.

Steel Fiber Reinforced Castable — Steel Fiber Castable

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The corundum steel fiber refractory castable has a good effect. Corundum steel fiber castables with different physical and chemical indicators are used in different industrial furnaces, such as steel-making electric furnaces, tundishes, heating furnaces, rotary kilns, and other thermal equipment. So, how much is a ton of corundum steel fiber refractory castable for the rotary kiln?

Generally, the price of corundum steel fiber castable is about 6,500 yuan per ton. However, there are many factors affecting the price of castables, and the details need to be determined based on the actual kiln situation and the use of castables.

The price of corundum steel fiber castable is a reference factor when customers purchase. But what you pay for is what you pay for. Refractory castables are different from other refractory products. Its quality is not only about the price, but also about the application. The better the effect of the application in high-temperature kilns, the more expensive it is. When purchasing high-quality corundum steel fiber refractory castables, it is best to provide refractory castable manufacturers with the working conditions of the furnace, such as operating temperature and service life. Then the refractory manufacturer will have a technical team to provide corresponding castable solutions to ensure the use of corundum steel fiber castables and calculate the cost of purchasing refractory castables.

To learn more about refractory castables for furnace refractory linings, please continue to follow our blog. For the price of high-quality refractory castables, please contact us.

Application and Configuration of Steel Fiber Refractory Castables

June 16, 2021March 26, 2021 by rsrefractorycastable

In the refractory industry, it is well known that steel fiber castables are prepared by adding stainless steel heat-resistant fibers. In addition to the conventional high-temperature abrasion resistance, the product has a certain amount of heat-resistant stainless steel fiber added to its ingredients to prevent the difference between the aggregate and the matrix in the material at high temperatures.

Steel Fiber Refractory Castable Sales — Steel Fiber Refractory Castables Sales

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Characteristics of Steel Fiber Castable

(1) Steel fiber strengthens the tensile and flexural strength of refractory castables.
(2) Castables of the same material. Castables reinforced with steel fiber will drop corners after 19 cycles of water cooling at 1100°C, while castables without steel fiber reinforcement will drop corners after 14 cycles. Excellent, which proves that steel fiber reinforcement can improve the thermal shock resistance of the castable.
(3) Steel fiber reinforced refractory castables can still bear the load even after cracking, thereby improving the fracture resistance of the castable and increasing the strength of the refractory castable.

The Main Application of Steel Fiber Castable

Which furnace parts are suitable for steel fiber refractory castables? Refractory manufacturers have compiled the following furnace parts for your reference.

Steel fiber reinforced castable is made of special grade bauxite clinker as aggregate, and high-quality bauxite clinker and corundum fine powder as matrix. It is made of superfine powder and other composite materials as binders and additives, plus stainless steel heat-resistant fibers. At the same time, due to the addition of steel fibers, the overall strength of the furnace wall is greatly enhanced after the material is poured. Steel fiber castables are mainly used in the following areas:

The inner lining of various thermal equipment.
The flue, heat insulation in the large-diameter metal chimney.
Industrial boiler lining, the effect is more obvious when used on the top of the furnace.
Low-temperature air (≤1200℃) heat insulation in the pipeline.
KT-J anti-carburizing fiber castable is used for muffle-free carburizing furnace lining.
Various general and special-shaped prefabs can meet the special application requirements of users.
Backing insulation layer (including furnace wall and furnace roof) with a variety of low-temperature furnace interface temperature ≤1050℃.
In industrial furnaces with flat flame burners, the roof of the furnace is sealed and insulated, and the sealing effect is better than any other materials.
Resistance furnace lining with task temperature ≤1200℃, the electric heating element can be exposed, and it can also be made into an embedded structure.
There is no mechanical vibration in the task, and the furnace lining with large temperature changes is especially suitable. Such as bell-type furnace, removable aluminum melting furnace cover, etc.
HS-J ultra-low temperature refractory fiber castable, ML-J polycrystalline mullite fiber castable, L80-J alumina fiber castable. It can be used for the lining of industrial furnaces with a task temperature of 1300-1450°C.
All kinds of fuel furnace lining with task temperature ≤ 1250℃, including furnace wall and roof. Different types of refractory fiber castables are used to make composite furnace linings, with fluctuating structure, economical and reasonable, and convenient construction.

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Performance and Formula of Steel Fiber Refractory Castable

The heat-resistant steel fiber used for common steel fiber refractory castables should be selected according to the use conditions of thermal equipment, and the appropriate amount should be determined. The preparation process as follows. First, weigh the refractory aggregates, powders, binders, and additives, dry mix 1mim, and then mix with water and wet, and evenly sprinkle the steel fibers into the material without forming agglomerates. After mixing for 1 min, the material can be discharged. The total mixing time shall not be less than 5 minutes. When vibrating rods are used for molding, the vibration direction should be staggered, so that the steel fiber distribution direction is reasonable and performance can be improved.

Items		1	2	3	4	5
Chemical Composition / %	Al2O3	65	90	74	68	84
	MgO	–	4.4	–	–	–
	CaO	1.4	3.2	1.5	1.2	2.0
Compressive Strength / MPa	1d	10	–	15	14	–
	110℃	14	69	40	49	150
	1000℃	40	–	70	74	–
	1500℃	43	91	76	80	150
Flexural Strength / MPa	110℃	6	11	5	6	–
	1000℃	12	–	11	12	19
	1500℃	13	21	13	13	23
High-Temperature Flexural Strength / MPa	1400℃	2.1	9.6	2.4	2.8	–
Line Changes after Burning	1000℃	-0.10	–	+0.08	-0.02	±0.1
Line Changes after Burning	1500℃	+0.22	+0.62	+0.30	+0.10	±0.1
Refractoriness / ℃		1770	1830	＞1790	＞1790	＞1790
Bulk Density / g/cm3		2.38	3.26	2.60	2.62	2.90

The above table shows the performance of a certain steel fiber refractory castable.

No. 1 is high-strength clay combined with refractory castable. The refractory aggregate and powder are made of third-grade and first-grade bauxite clinker respectively. In order to improve the performance of the matrix, fused brown corundum powder is added, and active SiO2 ultrafine powder and additives are added. Use CA-50 cement as coagulant.

No. 2 is fused calcium aluminate cement aluminum-magnesium refractory castable, dense fused corundum is aggregate, alumina and high-purity sintered magnesia powder are used as refractory powder, and superfine powder and compound additives are added at the same time.

No. 3 and No. 4 are low cement bauxite-mullite refractory castables, and refractory aggregates are made of first-grade bauxite clinker and mullite. The refractory powder is super-grade bauxite clinker powder or corundum powder, the binder is CA-70 cement, and superfine powder and composite admixtures are added at the same time.

No. 5 is a low cement, special alumina corundum refractory castable with a small number of additives. This type of high-quality refractory castable is used at higher temperatures, so the grade 330 heat-resistant steel fiber is selected. The equivalent diameter is 0.5mm, the length is 20mm, and the dosage is 2%. The water consumption is 6% ~7%. According to the selected mixing ratio, various raw materials are weighed and formed after kneading. After molding, it should be naturally cured and no water should be sprayed. After 24 hours of curing, remove the mold and continue natural curing for another 48 hours to check the performance.

With the development of unshaped refractory castables, prefabricated products of steel fiber refractory castables are also used in kiln parts. The information on this will be sorted out before sharing it with you.

How to Solve the Phenomenon on the Surface of Refractory Castables Preforms

June 16, 2021March 9, 2021 by rsrefractorycastable

Unshaped refractory castables and castable preforms have been widely used by more and more high-temperature industrial kilns due to their advantages of convenient, fast construction and low labor intensity. However, many enterprise users have found that refractory castables or preforms have found some abnormal phenomena during storage or maintenance, such as chalking, white hairs, and so on. So, how to solve the white hair and chalking on the surface of refractory castables preforms?

Firstly, let’s understand how these phenomena are formed.

In fact, these are caused by the contact of high-alumina cement hydration products in refractory castables with acid gases in the atmosphere. As the moisture in the castable evaporates, salt substances continue to migrate and precipitate to the surface, and then slowly aggravate the damage process of the refractory castable. We will analyze these phenomena today. Pulverization occurs during the storage of preforms made of cement-containing refractory castables. Some of them grow “white hair” on the surface, commonly known as white alkali, which causes the pulverization of the surface of the castable. In severe cases, the strength of the castable decreases.

White-Hair and Chalking on the Surface of Refractory Castables and Preforms — White-Hair and Chalking on the Surface of Refractory Castables Preforms

Several Phenomena on the Surface of Refractory Castables after Construction

Carbonation of Castables

Carbonation of high-alumina refractory castables is often considered to be one of the main reasons that lead to the decrease of castable structure and spalling. The high-alumina cement-bonded refractory castable is exposed to the air, and the hydration products therein react with the CO2 gas in the air to undergo a carbonation reaction. In addition, refractory castables are more likely to undergo carbonation under high humidity conditions and compared with dense castables, lightweight castables with high water content are easier to pulverize. This shows that in the presence of water, the hydration product interacts with the CO2 acid gas, and the PH value of the liquid in the single pore of the phase drops sharply, which makes all the new hydration organisms in the refractory castable become unstable.

Sulfation of Castables

Compared with the carbonation of high-alumina cement hydration products, the sulfation phenomenon has not attracted enough attention from the construction party and the user. In the atmosphere, in addition to the CO2 acid gas, there are also SO2, H2S, and other gases, which also have a strong corrosive effect on the hydration products of the matrix part of the high alumina cement castable. Eventually, this lead to powdering and peeling of the castable.

In addition to being sulphated by SO2 and H2S in the air, high-alumina cement hydrate may also interact with SO42- or H+ in the water source. As the activity and acidity of the two increase, the stability of the three high-alumina cement hydration products also decreases sharply.

Salt Precipitation Phenomenon of Castable

The salt precipitation phenomenon on the surface of refractory castables is another important factor that aggravates the structural damage of the castables. During the curing or natural drying process of refractory castable, some soluble carbonate, sulfate, chloride, phosphate, and other salt compounds will focus on the surface of refractory castable and crystallize with the evaporation of water. This phenomenon is often called salting out.

As the water evaporates from the surface of the refractory castable, these ions migrate and aggregate with the water molecules from the inside to the surface of the castable, or react with acid gases in the air on the surface of the castable. The salts formed after the hydrate reaction are focused on the surface. Finally, these salt compounds crystallized out due to exceeding the solubility in water.

In fact, all soluble salts containing crystal water include chloride, sulfate, carbonate, and so on. These salts all have the process of removing the crystal water, accompanied by the change of crystal form and volume change. These are some of the reasons that aggravate the pulverization, peeling, and lumps of the surface structure when the castable is cured in the air.

Solutions to the Phenomenon after the Construction of Refractory Castables and Preforms

(1) Dry the castable as soon as possible after construction to remove water and eliminate the carrier of sodium salt in the cast, so that the alkali stays in the construction body and no longer migrates to the surface.
(2) If the construction conditions cannot be dried in time, the pouring material should be sealed and the surface should be covered with plastic film to prevent moisture from migrating to the surface with alkali.
(3) The refractory castable is made of refractory raw materials with low alkali content to increase the viscosity and fast hardening of the refractory castable. It can reduce the migration speed of sodium salt, strengthen quality management, and strictly control the amount of water added to the construction.

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Rongsheng is a refractory manufacturer with an environmentally-friendly and advanced unshaped refractory production line. Rongsheng’s unshaped refractory production line has an annual output of 80,000 tons. Our refractory products have been sold to more than 60 countries and regions all over the world. Our customers of refractory castables have a high degree of recognition of our product quality and a high rate of return orders. Our monolithic refractory products can be customized according to the customer’s specific furnace requirements. We have rich experience in the field of wear-resistant refractory castables and refractory plastic products. In addition, he has rich experience in prefabricated refractory castables on the roof of the furnace. For more information about monolithic refractories, please contact us.

Performance Requirements of Al2O3-MgO·Al2O3 Refractory Castables for Steel Ladle

June 16, 2021November 28, 2020 by rsrefractorycastable

Ladle castables are used in steelmaking plants and foundries to receive molten steel and carry outpouring operations in front of open-hearth, electric furnace, or converter. Ladle castable is a kind of granular and powdery material made of refractory materials and a certain amount of binder for a ladle. Ladle castable is an unshaped refractory made of high alumina bauxite, corundum, and magnesia as the main materials, using composite micro powder and adding some additives.

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Ladle castables are made of bauxite clinker, corundum, magnesia, magnesium spinel, and ultrafine powder, etc., with different binders and additives. Its characteristics are strong corrosion resistance, good thermal shock resistance, good volume stability, suitable for medium and small ladle use, and long life. Good explosion-proof performance, high-temperature strength, slag corrosion resistance, and strong erosion resistance.

Al2O3-MgO·Al2O3 Refractory Material for Ladle

Al2O3-MgO·Al2O3 refractory materials are selected for the sidewalls and bottom of the ladle. The most common form is Al2O3-MgO·Al2O3 castables. The design of its chemical composition is mainly to use the eutectic phase region of the MgO·Al2O3-Al2O3 sub-system in the Al2O3-MgO binary system, and the area of MgO about 5%. As shown in Figure 5-26, its Al2O3 content is about 90%.

This castable not only has good corrosion resistance (see Figure 5-27), but also has excellent resistance to slag penetration, as shown in Figure 5-28 and Figure 5-29. Figures 5-27 and 5-29 show that the more spinel is added, the more spinel with high MgO content is added, the better the corrosion resistance. The resistance to slag penetration is preferably 90% Al2O3 spinel castable. This type of Al2O3-MgO-Al2O3 castable has a thin slag layer and fewer nodules during use, which protects the inner refractory material. Therefore, its durability is good.

The ω (MgO) in the spinel used in this type of Al2O3-MgO·Al2O3 castables is 10% to 30%, and ω (Al2O3) is 70% to 90%. The choice of spinel particles in castables is usually determined by test results.

The particle size of MgO·Al2O3 (20% content) has an effect on the infiltration of slag into the Al2O3-MgO·Al2O3 system. This shows that only when MgO·Al2O3 is added in the form of fine powder, the thickness of the slag soaked layer is the smallest. It can be seen that only when MgO·Al2O3 is evenly dispersed in the matrix of the Al2O3-MgO·Al2O3 brick can the slag penetrate into the deep part of the brick more effectively. The relationship between the amount of spinel added and the melt loss index and slag penetration thickness can be obtained for castables containing 10% to 30% MgO·Al2O3. The small thickness of the slag impregnated layer is an important basis for guiding the design formula.

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When the mixing amount of spinel is below 20% (mass fraction), fine powder less than 1mm is used. Under this condition, when the amount of spinel added increases, it has the effect of inhibiting slag penetration. When the amount of spinel is greater than 30% (mass fraction), particles larger than 1mm are used. Under these conditions, when the amount of spinel added increases, it has the effect of improving corrosion resistance. The damage of the castable due to structural spalling is much greater than that of Al2O3-C bricks, and the damage rate of the former is 1.3 to 2.5 times that of the latter. Compared with Al2O3-C bricks, the damage rate of castables is reduced by about 30%, showing better results.

At the most severely damaged ladle impact location, the damage rate of Al2O3-C bricks increases with the increase in the ratio of stainless steel to steel. Castable C has the same damage rate and service life as Al2O3-C bricks. When the Al2O3-MgO-Al2O3 series castable containing 20% spinel fine powder is applied to the sidewall of the ladle and the impact part of molten steel, it will not produce cracks and peeling damage during use, and has the characteristics of stability and durability.

The above research results show that the amount of spinel added has an important impact on the performance of aluminum-spinel fired bricks. This kind of fired brick also has the problem that the joints of the bricks are corroded first. To this end, a certain amount of fused magnesia particles can be added to the ingredients to cause residual linear expansion during use. Therefore, the problem of the brick joints being corroded first is prevented, and the service performance of the aluminum-spinel brick can be improved.

In addition, due to the high CaO content of dolomite, it has excellent impurity purification ability. Therefore, the lining of asphalt combined with dolomite bricks is the most economical material for smelting clean steel. The other is to use fired dolomite bricks as lining to produce ultra-low carbon steel.

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Rongsheng Unshaped Refractory Manufacturer

Rongsheng is an experienced manufacturer of refractory materials. Rongsheng not only sells various refractory brick products to customers all over the world but also provides overall refractory material solutions and refractory materials for various thermal furnace linings. Rongsheng’s advanced fully automatic monolithic refractory production line has an annual output of 80,000 tons. Rongsheng’s best-selling products include various alumina bricks, magnesia bricks, silica bricks, corundum bricks, mullite bricks, thermal insulation bricks, and other refractory brick products. There are also monolithic refractory products such as high-aluminum refractory castables, refractory plastics, refractory ramming materials, and refractory spray coatings. We also provide customers with high-quality refractory bricks and refractory castables for ladle lining. To get the price of Rongsheng refractory materials for free, please contact us. We will provide you with refractory lining materials that best suit your production needs based on your specific furnace conditions.

What are the Effects of Adding Silicon Carbide on Refractory Castables Properties?

June 16, 2021November 12, 2020 by rsrefractorycastable

Many people may wonder whether adding silicon carbide to refractory castables can increase strength? It is well known that adding silicon carbide to refractory castables can increase the strength of the castables. However, the addition of different proportions has different effects on the performance of refractory castables. What are the effects of adding silicon carbide on Refractory Castables Properties? Refractory manufacturers have come to the following conclusions by analyzing experimental data.

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What Effects Does the Addition of Silicon Carbide have on the Refractory Castables Properties?

The proportion of silicon carbide added in the refractory castable is too high, which will affect the strength of the castable at medium and low temperatures. Early mulliteification is prone to occur, and the stomata will be relatively reduced. However, the compressive strength of refractory castables increases at high temperatures.

If too little or no silicon carbide is added to the refractory castable, the strength of the castable will decrease by 25%. The current silicon carbide castable is actually a high-strength high-aluminum castable with few silicon carbides. Therefore, the high aluminum castable strength maintained by the castable without silicon carbide.

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The addition of silicon carbide to the refractory castable is too low, then it will not play the role of increasing the compressive strength of wear resistance. At this time, judging from its performance, it is just a high-aluminum castable. However, under certain conditions of severe lining erosion, it is still necessary to add silicon carbide to the high-aluminum castable to change the properties of the castable. In order to improve the thermal shock stability and wear resistance coefficient of the refractory castable, the service life of the lining is longer.

Of course, excessive addition of silicon carbide in the refractory castable will react with silicon dioxide, and too little addition will have no effect. How to balance it? Generally, when the furnace is not severely eroded and the erosion is not severe, add 6% silicon carbide to the refractory castable. It is the best balance ratio to use in the strength of semi-finished products or high-temperature areas.

The effect of the amount of silicon carbide added on the apparent porosity of the castable. With the increase in the amount of silicon carbide added, the apparent porosity gradually decreases after heat treatment at 1400 ℃. This shows that as the liquid SiO2 on the surface of silicon carbide increases, more closed pores are formed. At high temperatures, the apparent pores are continuously reduced, and the degree of densification will increase.

The effect of the amount of silicon carbide added on the linear change rate of refractory castables. With the increase of the amount of silicon carbide powder added, the linear rate of heat treatment at 1400℃ gradually decreases. The main reason is that the surface of silicon carbide is oxidized into a liquid SiO2 film at high temperature, showing a trend of increasing volume. This reaction occurs slowly from the outside to the inside, and correspondingly offsets the shrinkage of the substrate. In addition, 1100-1350 ℃ is also the formation stage of mullite. The outer layer of silicon carbide is oxidized to form liquid SiO2, which reacts with alumina powder to form staggered, acicular mullite crystal phases. Accompanied by the larger volume expansion, it compensates for part of the line shrinkage.

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The Influence of the Amount of Silicon Carbide Added on the Refractory Castables Properties

The effect of the amount of silicon carbide added on the high-temperature flexural strength of refractory castables. The high-temperature flexural strength of the refractory castable after firing at 1400°C, with the increase of the silicon carbide content, the high-temperature flexural strength is significantly enhanced, and it is much higher than that of the castable without silicon carbide. This is a very significant feature brought by silicon carbide.

When the addition amount of silicon carbide is above 5%, it has good alkali resistance. With the increase of the added amount, the corresponding corrosion resistance and thermal shock resistance can be improved. However, adding a small amount of silicon carbide to the corundum-mullite castable has an effect on the physical properties at room temperature, high-temperature flexural strength, and microstructure. At the same time, trace silicon carbide will not significantly increase the thermal conductivity and heat loss of the castable.

In summary, increasing the content of silicon carbide from 1% to 5% can increase the strength of the refractory castable after heat treatment at 110-1500°C. However, increasing the content of silicon carbide from 5% to 9% will affect the strength of the castable after heat treatment at 1100°C. After the addition of silicon carbide, the wear resistance of the castable is hardly improved after the 110°C treatment; after the 1100°C treatment, the wear resistance of the castable with the silicon carbide content of 1% to 5% is slightly improved. However, the wear resistance of castables with SiC content of 5%-9% is worse.

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The production of refractory castables does not go through high temperatures. The reason why the amount of refractory castables is now increased and has a wide range of uses. It is because the production cycle is short and the construction is convenient and quick. The iron parts and special parts of industrial furnace lining can play a better role. Even different manufacturers of refractory castables are constantly experimenting and updating the recipes of castables according to the actual use of customers, so as to better enable the castables to exert their best performance during use. Rongsheng is a refractory castable manufacturer with rich production and sales experience. Rongsheng’s advanced unshaped refractory production line has an annual output of tons. To get the price of refractory castables for free, please contact Rongsheng refractory castable manufacturers.

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Features of Lightweight Thermal Insulation Acid-Resistant Castables

Matters needing attention in the construction of light acid-resistant castables

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Industrial Kiln Insulation Refractory Castable for Sale

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Classification of Industrial Kiln Insulation Refractory Castables

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Properties of thermal insulation castables for industrial kilns

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Buy High-Quality Insulation Castables for Industrial Kilns

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The Difference Between Three Different Amorphous Refractories

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Refractory Mortar

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Refractory Cement

Refractory Castables (Refractory Concrete)

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The Damaged Appearance of Castable for Ladle

Damage to the slag line

Damage to the molten steel

The bottom of the package is damaged by the steel part

Damage Patterns of Refractory Materials for Ladle

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Question 1: The operating temperature of the kiln is 1500℃, what refractory castable should be used?

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Question 2: How much is a ton of corundum steel fiber refractory castable for the rotary kiln?

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Characteristics of Steel Fiber Castable

The Main Application of Steel Fiber Castable

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Performance and Formula of Steel Fiber Refractory Castable

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Several Phenomena on the Surface of Refractory Castables after Construction

Carbonation of Castables

Sulfation of Castables

Salt Precipitation Phenomenon of Castable

Solutions to the Phenomenon after the Construction of Refractory Castables and Preforms

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Rongsheng Refractory Castable Manufacturer

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Al2O3-MgO·Al2O3 Refractory Material for Ladle

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Rongsheng Unshaped Refractory Manufacturer

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What Effects Does the Addition of Silicon Carbide have on the Refractory Castables Properties?

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The Influence of the Amount of Silicon Carbide Added on the Refractory Castables Properties

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Rongsheng Refractory Castables Manufacturer

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