2020 - RS Kiln Refractory Bricks

During the smelting period of the refining furnace, along with the continuous increase in the temperature of the molten steel, the ladle refractories are corroded to varying degrees, and other reasons eventually cause the molten steel to penetrate the ladle wall, and the molten steel overflows. Especially during the period from the completion of smelting to continuous casting, if the ladle is worn through, the damage will be very serious. The staff and production equipment under the lifting route will suffer serious casualties and damage. Bring huge property losses to the steel company. Following, let’s learn about Emergency Measures for Ladle Leakage.

Possible Causes of Ladle Leakage Accidents

During the smelting period, the temperature of the refining furnace continues to rise, and the corrosiveness to the ladle continues to increase, resulting in redness of the ladle wall. If it is not found in time and cooling measures are taken, it is very easy to cause steel ladle leakage, and then cause production safety accidents.
The oxidation of molten steel is too strong, and the slag brought from the furnace will also have high oxidation. The high oxygen content of molten steel and high (FeO) steel slag will cause the corrosion rate of refractory materials to accelerate, and will also cause Ladle Leakage.
The quality of refractories is not good. The refractoriness, load softening point, and other indicators do not meet the standard requirements, and under normal molten steel conditions, corrosion will accelerate and cause Ladle Leakage.
Ladle lining masonry quality is not good. Ladle masonry does not meet the specification requirements, especially if the refractory brick for the ladle lining joints are too wide, the brick joints are not staggered, the brick joints are not evenly coated and other defects, it is easy to cause the molten steel to penetrate into the brick joints and cause the refractory bricks to fall off and float up to cause the Ladle Leakage.
Overuse causes ladle leakage also. In the process of using the ladle, it has been found that the lining of the ladle has a large erosion, and there is a risk of leakage.

Possible Signs before Ladle Leakage Accident

The furnace lining is severely corrosive.
The wall of the ladle is red and deformed.
The temperature of molten steel is abnormally high.
The surface of molten steel fluctuates abnormally.

Emergency Treatment Measures for Ladle Leakage Accidents

Measures to be taken when ladle leakage accidents are encountered at the smelting position of the refining furnace, hoisting, etc.

If undesirable phenomena such as excessively high molten steel temperature in the ladle or redness of the ladle wall are found, the team leader and dispatch should be notified immediately. The production technology department is notified by the dispatcher to jointly study preventive measures and report to the company leaders in time. At the same time, except for the personnel of rescue agencies and those who must insist on production, other personnel are not allowed to approach the bottom of the refining furnace, and no one is allowed to stand within 20 meters of the lifting route.
The furnace head immediately took measures to cool down. And immediately notify the workshop director and dispatcher, and the dispatching office will notify the Technical Quality Department to jointly study preventive measures. Report to company leaders in time.
Except for personnel from rescue agencies and those who must insist on production, all other personnel on the site are not allowed to approach the furnace bottom or within 20 meters of the lifting route.
After discovering that the wall of the package is red or burned through, the furnace supervisor on duty should immediately take measures to cool down and lift the safety ladle to the accident package area to prepare to turn the package. At the same time, an alarm was issued and other personnel was notified to evacuate. The dispatcher informs the chief surveyor, the safety department, the security department, the hospital, and the fire brigade, and activates the emergency plan. The on-duty dispatcher and the squad leader in front of the furnace must stick to their posts and quickly evacuate the scene after the accident is handled.
After the accident caused casualties, the furnace supervisor on duty organized personnel to carry out rescue work while handling the lifting of the ladle. Move the wounded to safety.
After receiving the notice, the Safety Section rushed to the scene immediately. Assist the workshop to seal off the scene, maintain the order of the scene, and assist rescuers in the rescue.
The dispatcher is responsible for contacting the ambulance and cooperating with the doctor to send the wounded to the hospital. At the same time, escorts are arranged.
Other personnel shall be uniformly organized and arranged by the headquarters. When gas leaks are found in gas equipment, gas pipelines, and ancillary facilities, they should immediately report to the workshop leader. The discoverer should be on guard to prevent unrelated persons from entering the gas leak area. If the leakage area is large, the gas protection station must be notified, and the safety department will send personnel to evacuate and guard the leakage area.

After receiving the notification, the production dispatching office will immediately notify the production office, safety department, emergency rescue team personnel, general dispatcher, security department, hospital, and fire brigade of the on-duty dispatcher. The company leaders ordered the launch of an emergency plan.
After receiving the notice, the electrical department will immediately switch on and off all electrical equipment on site. Eliminate secondary casualties due to leakage.
The captain on duty in the continuous casting process immediately organized personnel to close and remove the on-site gas blind valve, butterfly valve, oxygen point valve box valve, and other flammable and explosive gas valves and equipment.

Rongsheng refractory manufacturer reminds steel mill customers that security is no small matter. It is our vision to ensure the economic benefits of the enterprise under the premise of safe production. In the production and sales of refractory materials for refining furnace ladle, Rongsheng refractory manufacturers always put production safety first. Bulk supply kinds of refractory materials for the ladle refining furnace, such as refractory bricks and monolithic refractories, etc. To get the price of refractory materials for high-quality thermal furnace equipment for free, please contact us. We will provide you with refractory products that best suit your production needs according to your specific needs. There are various refractory materials for refining furnace walls.

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Blog

Nov 26 2020

Is High Alumina Refractory Mortar the Same as High Alumina Cement?

High alumina refractory mortar is prepared from high alumina bauxite clinker, binding agent, and admixture. It is usually delivered in bulk and dry, with water added for reconciliation.

The role of high alumina refractory mortar additives

Soft clay is added to high alumina refractory mortar to improve work abilities, such as spreadability and adhesion. Using soot silica powder instead of soft clay can lower the sintering temperature. Additives mainly include precipitation agents, stabilizers, plasticizers, and anti-shrinking agents. The role of the precipitation agent is to reduce the amount of water added. The stabilizer prevents the solid-liquid separation phenomenon of the adjusted refractory mud during the standing process. Adding plasticizers improves the spreadability of the mud and prevents flow. The anti-shrinking agent is to prevent cracks or peeling caused by volume shrinkage after sintering.

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Advantages of high alumina refractory mortar

(1) Good plasticity and convenient construction.
(2) High bonding strength and strong corrosion resistance.
(3) High refractoriness, up to 1750℃.
(4) Good resistance to slag invasion.
(5) Good heat peeling.

Use of high alumina refractory mortar

The high-alumina refractory mortar is correctly configured according to the materials of the bricks. Usually, it is mainly used for laying high alumina bricks and corundum bricks.

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How to use high alumina refractory mortar

When selecting fire mortar, the chemical composition similar to that of refractory bricks should be considered, so that the thermal expansion of the mud is consistent with the thermal expansion of the bonded refractory bricks to ensure that the masonry can be reliably bonded. It should have good masonry performance and high-temperature performance to bond the refractory bricks into a dense overall furnace lining.

The masonry performance of mortar refers to the work performance of refractory mortar in the masonry process, which is beneficial to ensure the quality of masonry. If there are good fluidity and plasticity. It has certain water retention performance and can maintain a uniform state without segregation and precipitation. It has proper consistency and viscosity during masonry and does not dry up during the brick kneading time, so as to achieve the required thickness of the brick joints, and the mortar in the brick joints is full.

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Is high alumina refractory clay the same as high alumina cement?

High alumina refractory clay is different from high alumina cement. Although both high-alumina refractory clay and high-alumina cement are powdered materials, there is a big difference between high-alumina refractory clay and high-alumina cement. High-aluminum refractory mortar is a synthetic material made by processing high-aluminum particles into powders smaller than 180 mesh and adding some binders and coagulants. The high alumina cement is the finished material after calcining bauxite and lime.

High-alumina refractory clay is a refractory material used in the joints of refractory bricks. The powder is high alumina powder plus a certain proportion of binding agent and coagulant. After adding water or adding a liquid binder, stir it into a slurry and apply it to 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. That is to say, it is the fire clay for bricklaying, which is a kind of finished solid powder.

High alumina cement is a kind of binder in refractory applications, and high alumina cement is also called aluminate cement. It is a clinker with 50% alumina content calcined with bauxite and lime. Aluminate cement is yellow or brown, and high-grade 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# cement 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 mortar is also divided into multiple grades, which can be used in conjunction with the construction of refractory bricks of various materials. It is divided into the high-aluminum refractory mortar, phosphoric acid combined with high-aluminum refractory mortar.

Therefore, high-alumina cement and high-alumina refractory mortar are completely different products, but they are closely related to refractory materials. They are also two of the most widely used materials in refractory products.

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Rongsheng unshaped refractory manufacturer

Rongsheng is a refractory sales manufacturer with an advanced and fully automatic unshaped refractory production line. Rongsheng’s refractory materials have been sold to more than 60 countries around the world. For example, Russia, South Africa, Kazakhstan, Philippines, Chile, Malaysia, Uzbekistan, Indonesia, Vietnam, Kuwait, Turkey, Zambia, Peru, Mexico, Qatar, etc. And got the customer’s continuous return orders. Rongsheng’s unshaped material production line has an annual output of 80,000 tons. Not only can we customize refractory materials according to your specific furnace conditions and production conditions. And can provide you with a refractory solution for the overall kiln lining. If you need to buy unshaped refractory materials, such as high alumina refractory mortar, high alumina refractory castable, high alumina cement, etc. Please contact us. We will provide you with services according to your specific needs.

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Industrial Refractory

Nov 9 2020

The Characteristics of Refractory Materials for Hazardous Waste Rotary Kilns

Refractory bricks are built inside the hazardous waste incineration rotary kiln to protect the rotary kiln from direct hazards due to high temperature and corrosion during hazardous waste incineration. The properties of Refractory Materials for Hazardous Waste Rotary Kilns depend on the composition and distribution of their phases and the chemical characteristics of each phase. In other words, it depends on the chemical mineral composition and chemical composition in the hazardous waste rotary kiln.

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Characteristics of Refractory Materials for Hazardous Waste Incineration Rotary Kiln

The main chemical components of refractory bricks used in general hazardous waste incineration rotary kilns include high alumina bricks, magnesia bricks, magnesia alumina bricks, and silica bricks. The content of Al₂O₃ in high alumina bricks is relatively high, generally around 70%. Magnesia bricks are mainly minerals composed of MgO and other metal oxides. Silicon bricks are mainly stable amorphous substances formed by SiO₂ and other metal oxides. Therefore, refractory materials for hazardous waste rotary kilns should have the following characteristics at the same time.

(1) High refractoriness. That is, high-temperature resistance, it needs to be able to operate in a high-temperature environment above 850°C for a long time without reaching the load softening temperature.
(2) Good wear resistance and flexural strength. The maximum stress that the refractory can withstand when it is bent on a 3-point bending device is required without breaking.
(3) Good chemical stability. To prevent the erosion and thinning of substances such as acid and alkali metals in the high-temperature flue gas. Relevant experimental studies have found that compounds of alkali metals (K, Na), halogens (F, Cl), and sulfur (S) are the main factors in the erosion and thinning of refractory materials.
(4) Good thermal stability. It can withstand the alternating thermal stress of the incineration state, and generally requires no less than 20 times of thermal shock resistance. That is, after heating and holding in a heating furnace at 1100°C for 15 minutes, the heated end is quickly embedded in flowing water at 5-35°C. After covering and cooling for about 3 minutes, take it out, observe the damage rate of the refractory brick, and calculate the number of times.
(5) The thermal expansion stability is better. Thermal expansion determines the expansion space reserved for refractory brick masonry. When the reserved space is insufficient, the refractory brick will explode and squeeze during high-temperature operation, resulting in an explosion. If the reserved expansion space is too large, the integrity of the rotary kiln may be poor. The middle gap is too large, resulting in non-integrity, and partial looseness, and may even fall off.
(6) The apparent porosity should be as low as possible. The apparent porosity refers to the ratio of the volume of all open pores in a material with pores to the total volume. Therefore, the higher the apparent porosity, the larger the volume of open pores contained in the refractory. The greater the probability of penetrating substances intruding into the refractory, the greater the erosion of the refractory, so the porosity needs to be controlled as low as possible. At present, domestically produced refractory bricks generally have a porosity of 20% and above.

Construction of Refractory Materials for Hazardous Waste Rotary Kilns

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Corrosion of Refractory Materials in Hazardous Waste Rotary Kiln

The materials entering the hazardous waste rotary kiln are mainly organic wastes such as industrial residues and chemical wastes. In the incineration process, the organic sulfur in hazardous waste undergoes high-temperature oxidation, mainly in the form of SO₃ and SO₂. The temperature of hazardous waste in the rotary kiln can reach 800~1300℃. In a high-temperature environment, SO₃ and SO₂ in the flue gas can easily react with minerals on the surface of refractory bricks to produce low-melting copolymers. The reaction equation of sulfur is as follows:

The corrosion of these low melting point polymers leads to serious loss of the bonding strength of the refractory bricks, forming a new low eutectic substance without bonding strength. This leads to the formation of low-melting polymers and low-melting substances on the surface of the refractory bricks. Driven by the movement and friction of the material, the surface will eventually fall off, resulting in the thinning of the refractory bricks.

Since the main components of silicon-alumina refractories are mullite and corundum, the main components are SiO₂ and Al₂O₃. The alkali metals contained in the hazardous waste can react with refractory bricks to generate nepheline-like substances and cause the volume expansion of refractory bricks. It may also cause the melting point to decrease, which in turn increases the corrosion effect on the refractory bricks, and accelerates the thinning rate of the refractory bricks, and shortens the service life.

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How to Improve the Performance of Refractory Bricks for Hazardous Waste Rotary Kiln

Pure magnesia refractories have very poor resistance to alkaline residues. However, when magnesia-alumina spinel is added to magnesia materials, it can well prevent the permeability of alkaline residues to refractory materials. And as the amount of magnesia-alumina spinel added increases, the penetration resistance will gradually become stronger, but the additional amount should not exceed 20%.

Sodium salts have a strong ability to corrode carbon-magnesia refractories, and it is possible to increase the effect of alkalis to a higher degree at lower temperatures.

After studying the reaction characteristics of alkali metals and refractory materials, the results show that changes in temperature, excess air coefficient, Cl content, and S content will all affect the migration of alkali metals. Therefore, it is recommended to choose composite components according to the actual situation when selecting molded refractories. The properties of refractory materials can resist the combined action of multiple corrosive factors.

Taking sodium carbonate as the research object, the corrosion mechanism of refractory materials is studied from the aspects of corrosion thermodynamics and kinetics. The results show that magnesia-containing refractories have better thermal stability than chrome-containing refractories.

Randomly take incinerator slag as a sample, and draw the following conclusions through some research and demonstration.

(1) Clay bricks, high alumina bricks, and chrome-containing high alumina bricks were used for erosion tests. The results show that the corrosion resistance of chrome-containing high alumina bricks is better than that of high alumina bricks and better than clay bricks. Considering that chrome is a toxic substance, high alumina bricks are selected as production bricks.
(2) Optimize the masonry method. Strictly control the key points of masonry to reduce corrosive infiltration to extend the service life of refractory bricks.
(3) Improve the quality of kiln-hanging leather by exploring the formula and method of kiln-hanging leather. Extend the kiln skin period, thereby increasing the protection of refractory bricks and reducing wear and erosion.
(4) Explore the best spray gun design by optimizing the liquid waste spray gun. In order to reduce the direct injection of liquid waste onto the surface of the refractory bricks, the corrosion and thinning of the refractory bricks will be caused.

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Rongsheng Refractory Manufacturer

Rongsheng is an experienced refractory material manufacturer. We also have rich experience in the production and sales of refractory materials for hazardous waste rotary kilns and cement rotary kilns. And every year, we can receive customer return orders. If you need to replace the refractory lining of your rotary kiln, or you need to build a new rotary kiln, please contact us. Our company’s refractory lining materials not only have the price advantage of the factory but also we provide high-quality customer service. Look forward to working with you.

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Steel industry refractories

Oct 27 2020

The Effect of Cement Addition on the Performance of Ladle Porous Plugs and Well Blocks

Ladle Porous Plugs are the most critical functional element in the bottom argon blowing process for molten steel refining, and their use conditions are very harsh. Ladle Porous Plugs can be divided into two types according to the assembly method: internal integral Porous Plugs and External combination Porous Plugs. The Porous Plugs’ core needs to be protected by supporting brick. At present, the well blocks for ladle are generally casted and used directly after curing, drying, and baking. The well blocks mainly undergo the following effects during use. (1) The brick working face is repeatedly subjected to rapid cooling and heating, which easily causes the brick to break and peel off. (2) Corroded and penetrated by molten steel and slag. (3) It is strongly scoured and worn by high-temperature molten steel. Therefore, it is required that the well blocks for ladle should have high strength, good thermal shock resistance, and excellent slag erosion resistance.

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The well blocks for ladle often appear cracks, transverse fractures, and block-dropping phenomena during use. It seriously affects its service life, and improving its thermal shock resistance is an important way to increase its service life. At present, there are many kinds of research on Porous Plugs, but not much researches on well blocks for the ladle. In this work, the effect of cement addition on the performance of corundum spinel ladles Porous Plugs was studied. It is expected to increase the service life of the Porous Plugs block, enhance its safety factor, and meet the requirements of steelmaking plants.

The effect of cement addition on the performance of ladle Porous Plugs and well blocks

(1) With the increase of cement addition, the normal temperature flexural strength and compressive strength of the sample after drying at 110°C gradually increase. The normal temperature flexural strength and compressive strength of the sample after being burned at 1560°C first increase, then decrease, and then increase. The linear change after burning first increases and then decreases. When the cement content is 6% (w), the strength is lowest. The apparent porosity and linear change rate after firing are the largest, and its performance is the worst.
(2) With the increase of cement addition, after three thermal shocks after water cooling at 1100°C, the strength retention rate of the sample after firing at 1560°C gradually increases, and the thermal shock resistance is improved. When the mass fraction of cement is 10%, the thermal shock resistance is the best.
(3) The anti-burst performance of the samples added with an anti-explosion agent is obviously improved. Especially the anti-explosive effect of sodium bicarbonate or sodium bicarbonate + polypropylene organic fiber composite is the best.
(4) The service life of high-purity corundum spinel bottom-blown argon-blown ventilating bricks with a cement addition amount of 6%-10% (w) and a compound explosion-proof agent has been increased from the original average of 31 times to an average of 36 times.

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Comparison of performance of chrome corundum Porous Plugs block and corundum-spinel Porous Plugs block

Chrome corundum, as a traditional material for ladle Porous Plugs block, has played a very important role for a long time. Due to the insufficient performance of traditional chrome corundum bricks in thermal shock resistance, it is prone to cracks during use. It is very easy for molten steel to invade the brick body along the gas inlet that produces cracks, forming molten steel penetration, which will seriously affect the effect of argon blowing. In addition, chromium can also pollute the environment. Therefore, chrome corundum Porous Plugs block have been gradually replaced by corundum spinel Porous Plugs block with better performance. However, chromium corundum Porous Plugs blocks are better than corundum-spinel Porous Plugs blocks in terms of body stability and resistance to slag penetration.

Performance Comparison of Chrome Corundum Brick and Corundum-Spinel Brick

The material of chromium corundum is a sintered tabular corundum with compact structure, low porosity, and easy sintering as the main raw material. There are some differences in the performance of the two types of Porous Plugs blocks. Generally speaking, the volume density of the corundum-spinel Porous Plugs block is smaller than that of chrome corundum Porous Plugs block under the same particle size gradation. The porosity of corundum-spinel brick is lower than that of chrome corundum brick. This is because, during the firing process, the swelling of the body caused by the formation of spinel offsets part of the shrinkage caused by the fine powder, resulting in a decrease in porosity. On the other hand, the linear change rate of the corundum-spinel Porous Plugs block is slightly larger than that of the chrome corundum Porous Plugs block. That is to say, the volume stability of corundum-spinel Porous Plugs blocks is not as good as that of chrome corundum bricks, mainly because magnesia alumina spinel is generated during the firing of corundum-spinel Porous Plugs blocks.

Since the slits of slit-type Porous Plugs blocks are relatively narrow, generally about 200 μm. If the volume of the Porous Plugs block changes greatly during the firing process, it will affect the size of the slits, and ultimately affect the air permeability and blowing effect. As a result, the performance of the Porous Plugs block is reduced during the use, the blowing rate is reduced, and even the blowing is blocked. Since the thermal shock stability of the spinel is better than that of corundum, the thermal shock stability of the corundum-spinel Porous Plugs block is better than that of chrome corundum Porous Plugs block. The corrosion index of the two slag resistance is the same, but the slag penetration resistance of the chrome corundum brick is stronger than that of the corundum-spinel brick.

Generally speaking, corundum-spinel Porous Plugs blocks are better than traditional chrome corundum Porous Plugs blocks in terms of performance. The traditional chrome corundum Porous Plugs block has been gradually replaced by it. Corundum-spinel Porous Plugs blocks are gradually becoming the mainstream ladle Porous Plugs blocks today.

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Rongsheng Kiln Refractory Material Manufacturer

Rongsheng is an experienced refractory material manufacturer and sales company. Rongsheng’s refractory products have served refractory lining projects in more than 60 countries around the world. We have a wealth of refractory lining solutions for refractory linings for steel smelting furnaces, glass kilns, and cement kilns. If you want to buy refractory materials for ladle, please contact us. We will provide you with services according to your specific needs.

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Blog

Oct 10 2020

Non-Burning Bricks for Ladle

Non-burning bricks for ladle include alumina-magnesia bricks, alumina-magnesia-carbon bricks, and magnesia-alumina-carbon bricks. The difference between their fired bricks is that they use water glass or phenolic resin as the bonding agent and undergo low-temperature treatment after molding. During the use of non-fired bricks for ladle, the alumina and magnesia in the matrix form spinel, and the carbon in the graphite and resin binder forms a carbon chain network structure. Therefore, the strength, slag resistance, and thermal shock resistance of refractory bricks for ladle are further improved. To get the price of refractory bricks for ladle for free, please contact Rongsheng refractory brick manufacturer. Next is the introduction of unburned bricks for a ladle.

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Alumina-Magnesia Brick and Alumina-Magnesia-Carbon Brick

First of all, let’s learn about the non-burning bricks for ladle combined with water glass, including alumina-magnesia brick and alumina-magnesia-carbon brick. The aggregate of the alumina-magnesia brick is generally first-grade bauxite, and the powder is super-grade bauxite clinker powder and first-grade magnesia powder. Use high modulus water glass as the bonding agent. After pressing, the finished product is treated at a low temperature of 150°C. The refractory brick is used on the large and medium-sized die-cast ladle, and its life span is generally 60 to 90 times.

Alumina-magnesia-carbon bricks are successfully manufactured on the basis of alumina-magnesia bricks and magnesia-carbon bricks, and the production process is similar to that of magnesia-carbon bricks. Water glass is combined with alumina-magnesia-carbon bricks, and primary and secondary alumina clinker is used as a refractory aggregate. The first-grade or super-grade high-alumina powder is used as refractory powder, and 8%~13% of the first and second-grade metallurgical magnesia powder is blended. The carbon material adopts electrode powder, earthy graphite, or flake graphite, the amount of which is 3%~8%, and the water glass solution (m=2.4~3.0) is used as the binding agent. After forming, the finished product is processed at a low temperature of 200~250℃. The refractoriness of the water glass bonded alumina-magnesia-carbon brick is 1770℃, and the 4% load softening temperature is 1320~1340℃, which is caused by more Na2O in the binder. If high modulus sodium silicate is used to bring in less Na2O, the load softening temperature will increase to 1410℃, and the refractoriness will be 1790℃. This kind of refractory brick is widely used in medium and small ladle due to its better performance and low price. The refractory brick is applied to the mold-cast ladle, and the slag line area is built with magnesia carbon bricks, and its life span is 50-100 times.

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Resin-Bonded Alumina Magnesia Carbon Brick

The raw materials of resin-bonded alumina-magnesia-carbon bricks use first-grade or super-grade bauxite clinker, white corundum, sub white corundum, and magnesia-alumina spinel as aggregates and powders. The magnesia powder is made of high-quality sintered magnesia or fused magnesia with Mg>95%, and mixed with flake graphite, high-quality silicon carbide and alumina powder or SiO2 powder. The phenolic resin binder is used for high-pressure molding, and the bricks are then processed at a low temperature of about 200°C to become the finished product. The refractory brick has the advantages of excellent strength, corrosion resistance, peeling resistance, thermal shock resistance, and non-sticky slag. However, the thermal conductivity is relatively large, and heat insulation measures must be taken during use.

It is better to directly add an alumina-magnesia spinel compound fired material into the alumina-magnesia-carbon bricks than doping with magnesium oxide. Because magnesia oxide can form spinel with alumina during use. Synthetic alumina-magnesia spinel should generally be sintered in a rotary kiln at a temperature greater than 1600°C. The higher the temperature, the better the quality. Its bulk density is 2.95~3.10g/cm3, and its content of alumina and magnesia should be greater than 91%. The fused magnesia-alumina spinel is more expensive. To ensure the quality of refractory bricks, suitable magnesia-alumina spinel should be selected.

Resin-bonded alumina-magnesia-carbon bricks have been widely used in the continuous casting ladle of many steel plants. On the 50-100t steel ladle for continuous casting, mid-grade alumina-magnesia-carbon bricks are used as lining. The slag line area is built with high-quality magnesia carbon bricks, and the service life is generally 50 to 80 times, up to 100 times.

In the 1990s, a large number of high-quality alumina-magnesia-carbon bricks and magnesia-carbon bricks for slag line areas were used in the lining of refining furnaces. The service life of the refining bag is more than 30 times, and the service life of LF(V) of 40~90t is about 50 times.

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Magnesia Alumina Carbon Brick

The production process of magnesia-alumina-carbon brick and alumina-magnesia-carbon brick is basically the same. It is the pre-synthetic spinel mixed with fused magnesia, and the difference in linear expansion coefficient between the two forms micro-cracks during high temperature and cooling use to buffer the thermal stress generated by temperature changes and reduce thermal spalling. Because the elastic modulus of spinel (MA) and periclase (M) are quite different, the former (0.012~0.022)×106MPa, the latter (0.059~0.49)×106MPa. Tough spinel helps to improve the thermal shock resistance of refractory bricks. In addition, the carbon material is added to the periclase-spinel, and about 10% graphite is added. After making it evenly distributed in the refractory brick body, the carbon atoms form a staggering network structure at high temperature, so that the material has a good high-temperature performance. In addition, graphite has high surface tension and a small wetting angle, which can effectively prevent the penetration of molten slag.

For example magnesia-alumina-carbon bricks for 75t LF lining of a steel plant. MgO 71%, Al2O3 13%, C 10%, apparent porosity 3%, bulk density 3.08g/cm3, compressive strength 50MPa, high temperature flexural strength (1400°C) 8MPa. The slag line uses high-quality MgO-C bricks, with a service life of more than 50 furnaces.

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Rongsheng Refractory Brick Manufacturer

Rongsheng is an experienced refractory manufacturer. Rongsheng’s refractory brick products have been recognized by customers in more than 60 countries around the world. Rongsheng’s project of refractory materials for ladle also has very strong competitiveness. If you need to buy refractory materials for ladle, please contact us. We will provide you with services according to your specific needs. You are welcome to consult and learn more about non-burning bricks for ladle.

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Steel industry refractories

Sep 30 2020

Development of Refractory Materials for Ladle Lining

The ladle is an extremely important metallurgical equipment in the steelmaking process. Its role is not only the ladle for carrying molten steel in the traditional sense but also the core carrier of the refining process outside the furnace. The choice of Refractory Materials for Ladle Lining is not only related to the life and cost of the ladle but also directly affects the output and cleanliness of molten steel. Let’s look at the use and development of refractory materials for ladle lining in a steel plant in the past 20 years.

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Development of refractory materials for ladle lining

According to a steel mill, they have 3 types of the ladle. In the order of commissioning, they are 120 t ladle, 150 t ladle, and new 150 t ladle, of which the new 150 t ladle is modified from the original 40 t ladle. The refractory materials used in different ladles are different due to different specific production requirements.

40 t ladle

Initially, the lining of the 40t ladle was entirely made of alumina-magnesia machine-made bricks, the thickness of the bottom bricks was 300 mm, and the thickness of the wall was 120 mm. Due to the shortcomings of alumina-magnesia machine-made bricks such as thermal shock stability and poor high-temperature strength, the life of the 40 t ladle bottom is only about 40 furnaces, which cannot be synchronized with the body bricks. Later, magnesia-carbon bricks were used for the bottom of the bag, and alumina-magnesia machine-made bricks were used for the wall and slag line, and the overall service life reached more than 100 furnaces.

120 t ladle

At the initial stage of production, the Refractory Materials for Ladle Lining of 120t ladle is made of alumina-magnesia machine-made bricks, the thickness of the bottom brick is 300 mm, and the thickness of the wall brick is 160 mm. In the early stage, the life of the ladle can be up to 90 furnaces when it is cast directly on the ladle. After the application of the refining process, as the refining ratio continues to increase, the life of the ladle is significantly reduced. The main reason is that the electrodes of the LF refining furnace heat up the molten steel and slag near the slag line, and the alumina-magnesia bricks are quickly melted and lost at high temperatures. In addition, refining will extend the residence time of molten steel in the ladle and also accelerate the erosion of alumina-magnesia bricks. Beginning in 2009, full magnesia carbon bricks have been used in 120t ladle. Magnesia carbon bricks have excellent slag resistance and high-temperature stability, and their service life can reach more than 110 furnaces in a smelting environment with a high refining ratio.

150 t ladle

Steel grades such as cold-rolled plates for automotive plates produced by the 150 t converter system have strict requirements on the carbon content and cleanliness of the molten steel. Therefore, from the initial stage of production, the 150 t ladle has adopted the process route of ladle bottom, clad wall alumina-magnesia machine-made bricks, and slag line magnesia-carbon bricks. At the same time, considering the CAS furnace process, the breathable brick is set in the center of the bottom of the bag, just in the molten steel impact area, and the molten steel has a serious impact on the breathable brick. In addition, due to the poor high-temperature performance of the alumina-magnesia machine-made bricks, the bottom working lining and the air-permeable bricks are severely broken. The life of the ladle is only about 70 furnaces, which cannot meet the needs of production rhythm. Later, magnesia carbon bricks were also used at the bottom of the package, and the problem of broken bricks and excessive melting loss at the bottom of the package was improved.

Application of Carbon-free Lining Materials

After a series of technical optimizations, the steel plant’s refractory materials for ladle are basically finalized. That is, magnesia-carbon bricks with 14% C mass fraction are used for the bottom and slag line, the walls are made of alumina-magnesia machine-made bricks combined with lignosulfonate, and the permanent layer is made of alumina-magnesia castable. The ladle of this material can basically meet the production rhythm of converters and continuous casting at that time. The three bricks and slag line bricks are replaced once every 20-30 furnaces are used, and the slag line bricks are replaced 1 to 2 times during the entire service process. With the development and production adjustment of various steels, the proportion of refining outside the ladle furnace is getting higher and higher. Low-carbon and ultra-low-carbon automobile panels have strict requirements on the carbon content of the lining. Traditional linings can no longer meet the production needs, so carbon-free linings have emerged.

Since 2015, steel plants have tested corundum spinel-based carbon-free materials on 150t ladle and will be promoted throughout the plant in 2016. The upgraded ladle bottom and wall are corundum spinel bricks, and the slag line uses improved magnesia-carbon bricks with 14% C mass fraction.

Corundum Spinel Bricks

The corundum spinel brick is developed under the background of the leapfrog development of refractory raw material production technology. It is a comprehensive upgraded product of alumina-magnesia machine-made bricks. The main raw materials are fused corundum, sintered corundum, fused magnesia fine powder, Al2O3 powder, alumina-magnesia spinel powder, pure calcium aluminate cement, and additives. It has the advantages of good high-temperature stability, strong corrosion-resistance, and high matrix strength.

There are 2 types of corundum spinel brick, organic pressed brick and prefabricated block. The former uses lignosulfonate as the binding agent, and the latter uses cement or alumina gel as the binding agent. The ladle built with prefabricated blocks has a better actual use effect. The machine-made bricks are easy to peel off on the upper part of the bag wall and the bricks are easy to break in the impact area of the bottom of the bag. The main reason is that the machine-made brick fine powder and aggregate are forcibly pressed together by the brick press. During use, the spinel reaction volume expands, which will cause the matrix to crack and become loose. In addition, the critical size of the machine-made brick aggregate is smaller than that of the prefabricated block, and the thermal stress caused by the temperature difference between the hot end and the cold end of the bottom-clad brick can easily break the brick body with a thickness of 300mm. The thermal strength of the prefabricated block is higher than that of the machine-made brick, so the bottom of the prefabricated block is not prone to faults.

The main phases of alumina-magnesia machine-made bricks are corundum, periclase, and mullite. The main phases of corundum spinel machine-made bricks are corundum, periclase, spinel, and α-Al2O3 micro powder. The main phases of the corundum spinel prefabricated block are corundum, spinel, α-Al2O3, and tricalcium aluminate. For details, please see Figure 2.

Figure 2 XRD patterns of alumina-magnesia machine-made brick (B1), corundum spinel machine-made brick (B2), and prefabricated block (B3)

The corundum spinel prefabricated block has two binder systems. One is pure calcium aluminate cement and alumina-rich spinel powder. The other is a gel combination system of ρ-Al2O3 gel, fused magnesia fine powder, and SiO2 fine powder. The prefabricated block of the cement-spinel system has the characteristics of high thermal strength, small volume expansion, and strong erosion resistance, and is suitable for use in the bottom working layer of the package. The prefabricated block of the gel-magnesia fine powder system has good slag resistance and thermal shock performance due to the in-situ generation of magnesia-alumina spinel and is suitable for the working lining of the clad molten pool. Starting in 2018, the steel plant eliminated corundum spinel machine-made bricks. All prefabricated blocks are used for the bottom and wall of the bag, and the melting loss of the working lining is effectively reduced.

High-performance Slag Line Magnesia Carbon Brick

The proportion of LF refining in steel plants is as high as 60%. Some steel grade liquid slags have low basicity, low viscosity, and thin slag layer. These process characteristics bring great challenges to the slag line working layer. The slag line material before 2015 was ordinary magnesia carbon brick, and the main raw materials were ordinary fused magnesia, antioxidant, flake graphite, and phenolic resin. Its corrosion resistance and oxidation resistance are not strong, and the melting rate is very fast. In accordance with the characteristics of the refining process of the steel plant, the magnesia carbon brick formula has been greatly adjusted since 2016. Use 98 fused magnesia as an aggregate and fine powder to improve the corrosion resistance of magnesia carbon bricks. Partially modified graphite is used to replace flake graphite and a nano-carbon source is introduced, which significantly improves the thermal shock resistance and mechanical properties of magnesia carbon bricks. The overall performance of the slag line magnesia carbon brick has been greatly improved.

In recent years, the changes in the physical and chemical properties of ladle slag line bricks are shown in Table 3. Since 2012, the magnesia carbon brick formula has been adjusted three times to improve the grade of magnesia. Improve the performance of graphite, reduce the high-temperature flexural strength to improve corrosion resistance.

Table 3 Ladle slag line magnesia carbon brick — Table 3 Comparison of physical and chemical properties of magnesia carbon bricks in the ladle slag line in recent years.

Optimization of Permanent Layer Refractory Materials

Before 2016, the permanent layer material used in steel mills’ ladle was traditional alumina-magnesia castable. The mass fraction of alumina is 65% to 70%, and the mass fraction of magnesium oxide is 8% to 10%. The material has the advantages of low cost and good volume stability at medium temperature. However, long-term use in a medium and low-temperature environment has serious attenuation of strength (hereinafter referred to as thermal attenuation), and the problem of poor volume stability at high temperatures is more obvious. In addition, alumina-magnesia castables are heavy materials with high bulk density and large thermal conductivity, which are not conducive to the development of lightweight ladle and the improvement of thermal insulation.

Beginning in 2017, high-alumina castables have been used on the ladle, with a bulk density of 2.453 ~ 2.55g/cm3. It not only guarantees the safety of the permanent layer but also takes into account the heat preservation. Due to the limited crane lifting capacity of the 120t converter smelting system, it is necessary to design a more lightweight ladle permanent layer material. Finally, mullite castable was used, and its bulk density was 2.0～2.1g/cm3. After laboratory tests and field tests, the two new permanent layer materials are significantly better than alumina-magnesia castables in terms of medium and high-temperature strength, volume stability, and corrosion resistance (see Table 4).

Table 4 Comparison of permanent layer pouring and cooking performance

Development Trend of Refractory Materials for Ladle Lining

The general development trend of ladle refractories is to reduce consumption and improve cleanliness. Reducing consumption not only refers to reducing the cost of refractory materials per ton of steel in ladle but also requires reducing the consumption of refractory materials per ton of steel. The purpose is to reduce the pollution of refractory materials to molten steel. To improve cleanliness, on the one hand, use anti-melting lining materials, on the other hand, select non-carbon materials, calcium materials, and other refractory materials that do not pollute molten steel to meet the requirements of producing high-grade clean steel. The next stage of the development direction of steel mill ladle refractories is mainly the following aspects. (1) The permanent layer promotes high-strength and light-weight materials to improve the thermal insulation of the ladle. (2) Promote the whole pouring scheme of the working lining to improve the service life. (3) Establish an information platform for online monitoring of steel ladle, and improve operational safety by implementing safety monitoring.

Learn more about the ladle refractories…

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Sep 15 2020

Several Different Types of “T” Refractory Bricks

T19 refractory bricks also called ax bricks. The size of the T19 mullite brick is 230×114×65/55mm. The country stipulates the size of bricks in order to facilitate calculation and save resources. There are many types of refractory bricks, and their shapes and sizes are quite complicated, but they all stipulate a unified brick number. People with rich experience and knowledge of refractory bricks can know its purpose, even shape, size, and weight from the brick number. For example, bricks with the prefix “T” are commonly used in general industrial furnaces. From “T-1” to “T-105”, there are more than 20 shapes and 105 brick numbers (specifications). Another example is the bricks with the prefix “G” are used for blast furnaces. There are two shapes and 8 specifications from “G-1” to “G-8”. The size of the T19 refractory bricks produced and processed by Zhengzhou Rongsheng Refractories is strictly implemented in accordance with the standard size, and customers are welcome to come and inspect. Next, let’s learn more about the “T” refractory bricks.

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Several Different Types of “T” Refractory Bricks

The cylindrical lining uses T3 bricks to match T38 bricks and T39 bricks (thicker lining). Or use T3 bricks with T19 bricks and T20 bricks (thin lining) for masonry. When designing, we must go through strict calculations to ensure that the “T” refractory bricks joints are basically the same.

T3 is a standard brick with dimensions (length×width×height): 230×114×65.
T38 and T39 are wedge-shaped bricks, also called knife-shaped bricks, with dimensions (length×width×height) respectively: 230×114×65/55 and 230×114×65/45.
T19 and T20 are called ax-shaped bricks, and the dimensions (length×width×height) are 230×114×65/55 and 230×114×65/45, respectively.
The thickness of T38 and T39 is gradually reduced from 65 to 55/45 in the length (230) direction.
The thickness of T19 and T20 is gradually reduced from 65 to 55/45 in the width (230) direction.

One Kind of Refractory Bricks — One Kind of “T” Refractory Bricks

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T19 Mullite Bricks

T19 mullite bricks are mainly used in metallurgical hot blast furnaces with high blast temperature above 1400℃. The parts and slag lines of the torpedo car hit by molten iron. The roof of the steel-making electric arc furnace, the forehearth of the glass melting furnace, the regenerator arch, and the upper structure. Ceramic sintering kiln, ceramic roller kiln, tunnel kiln, electric porcelain drawer kiln, dead corner lining of petroleum cracking system, glass crucible kiln, and various electric furnaces, etc. The wall of the clarifier, cement and lime rotary kiln lining, etc. They can be directly contacted with flame.

Mullite bricks are aluminum-silicon refractory products with mullite as the main crystal phase. Because the main crystal phase of mullite brick is mullite. Therefore, the properties of mullite bricks are as follows: the high-temperature resistance of mullite bricks can reach above 1790℃, the starting temperature of load softening is 1600-1700℃, and the compressive strength at room temperature is 70-260MPa. Good thermal shock resistance, high strength, low high temperature creep rate, low expansion coefficient, low thermal coefficient, and acid slag erosion resistance. It can also greatly reduce the weight of the high-temperature furnace body, transform the structure, save materials, save energy, and improve production efficiency.

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Rongsheng Refractory Bricks Manufacturer

The mullite bricks produced by Zhengzhou Rongsheng Refractory Bricks Manufacturer are mainly divided into lightweight mullite bricks and corundum mullite bricks. Lightweight mullite bricks use imported tabular corundum and high-purity fused corundum as the main raw materials. It is made by applying advanced superfine powder adding technology, mixing, drying, forming, and firing in a high-temperature shuttle kiln. Corundum and mullite refractory bricks are made of dense fused corundum and alumina powder as the main raw materials, which are mechanically mixed and high-pressure forming and high-temperature firing. Through the purity of the corundum sand and the process formula to meet the requirements of different corundum products using temperature.

Zhengzhou Rongsheng Kiln Refractory Material Co., Ltd. produces and processes various types of refractory materials. If you have a demand for T19 refractory bricks, T19 mullite bricks, etc. Rongsheng Company can provide you with high-quality products. For more information, please contact us. We will provide you with services according to your specific needs.

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Sep 9 2020

Corundum Bricks on the Tapping Channel of the Heating Furnace

In the small and medium-sized steel rolling heating furnace with side discharge, the tapping trough is an important part of the heating furnace. The structure of the tapping trough is directly related to the energy consumption and service life of the heating furnace. Because corundum bricks such as chrome corundum bricks and zirconia corundum bricks have good high temperature wear resistance and slag resistance. As a result, it has gradually replaced water-cooled cast iron tapping channels and has been widely used in small and medium-sized steel rolling furnaces. Rongsheng refractories manufacturer provides you with high-quality refractories for steel rolling furnaces, such as corundum bricks on the tapping channel, etc.

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Factors Affecting the Service Life of Corundum Bricks on the Tapping Channel

In actual production, improper construction and use often reduce the service life of corundum bricks on the tapping channel of the heating furnace. Therefore, it is of great significance to analyze the factors that affect the service life of corundum bricks and discuss measures to improve the service life of corundum bricks. To analyze the service life of corundum bricks on the tapping channel of the heating furnace, it is necessary to conduct a dialectical analysis from the characteristics of the corundum brick itself and the working conditions of the tapping channel of the heating furnace.

(1) Due to the high density of corundum bricks, thermal stability is poor. Therefore, it is easy to burst when the temperature changes sharply, especially near the tap hole. When the furnace pressure fluctuates frequently, the door of the furnace may burst into flames and sometimes suck cold air. As a result, the surface temperature of the corundum bricks fluctuates up and down, forming large internal stress. This causes the surface of the corundum brick to peel off and crack.

(2) The gap between the corundum bricks is not tightly sealed, and the oxide scale or its melt enters the gap and adheres to the upper oxide scale, forming a solid whole with the corundum brick. As a result, it is difficult to remove the oxide scale on the surface, and it must be removed with a big steel hammer. Doing so is easy to cause damage to the corundum brick, often cracked or knocked off.

(3) The masonry of the refractory bricks at the bottom of the corundum bricks must be smooth, and castables can be used to level them when they are uneven. It is not allowed to use loose thermal insulation materials, and it is not allowed to pay only part of it. In other words, the corundum bricks must be cushioned with hard refractory materials. Only in this way can it be ensured that the corundum bricks will not loosen when the billet slides on the corundum bricks. The loosening of corundum bricks will cause two undesirable consequences. One is to make the upper surface of the corundum bricks uneven, which affects the sliding of the billet and the elimination of oxide scale and reduces its service life. Second, the gaps filled with magnesia powder appear again due to the loosening of the corundum bricks, and the oxide scale will fall into it, which will cause difficulty in removing the oxide scale and reduce the service life of the tapping trough.

(4) Avoid “cutting” of corundum bricks by continuous casting billets. Most of the small and medium-sized steel billets have irregular shear sections. If the billet moves in the direction of the tapping channel, the surface of the corundum brick will be cut, which reduces the service life of the corundum brick. Therefore, when the billet enters the furnace, the placement of the billet should be adjusted to avoid the cutting of the corundum brick by the billet when it moves in the tapping trough, which can increase the service life of the tapping trough. Expansion joints or improper setting of expansion joints will make it have no room for expansion when heated, which will easily cause great internal stress, leading to premature damage to the corundum bricks and reduced service life.

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How to extend the service life of corundum bricks on the tapping channel of the heating furnace?

(1) Reasonably control the furnace pressure so that the furnace pressure is always slightly positive. Especially when the steel rolling production is abnormal, attention should be paid to adjusting the flue gate at any time to keep the furnace pressure in a slightly positive state. Ensure that no cold air is sucked at the door of the tapping furnace so that the surface temperature of the corundum brick near the tapping port will not change frequently.

(2) The masonry gap between corundum bricks must be as small as possible. After the masonry is completed, the gaps must be filled and compacted with magnesia powder. Leave 30-50mm expansion joints at both ends of the tapping trough, which are filled with alumina silicate refractory fiber felt and covered with 30mm thick magnesia powder. In this way, the longitudinal expansion stress of the corundum bricks on the tapping channel can be eliminated, and the oxide scale can be prevented from falling into the expansion joints. The expansion joints on both sides of the tapping trough are the same as the two ends, but the expansion joint width is 10mm.

RS Refractories Bricks for Kinds of the Heating Furnaces

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Rongsheng Refractory Bricks Manufacturer

Rongsheng is an experienced corundum refractory brick manufacturer. Rongsheng’s refractory products have been sold to more than 60 countries and regions all over the world. For example, Thailand, UAE, Turkey, Kuwait, South Africa, Malaysia, Vietnam, Netherlands, Philippines, Singapore, Egypt, Russia, etc. Rongsheng’s refractory technology team aims to provide the most suitable refractory materials for the refractory lining of various thermal furnace equipment, including refractory bricks and refractory castables. If you need refractory equipment on your heating furnace equipment, please contact us. We will provide you with services according to your specific needs.

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Aug 31 2020

Characteristic Analysis of High-strength Wear-Resistant Castables for Waste Incinerators

High-strength wear-resistant castable is a widely used castable refractory for furnaces. High-strength wear-resistant castables can be used in circulating fluidized bed boilers, corrosion-resistant liners in the chemical industry, wear-resistant liners in the coal industry, blast furnace linings in the steel industry, and garbage incinerator linings. The Rongsheng refractory manufacturer analyzed the characteristics of high-strength wear-resistant castables for waste incinerators based on the characteristics of waste incineration. And specially developed wear-resistant refractory castables for garbage incinerators.

Application of High-strength Wear-Resistant Castables

Generally, high-strength wear-resistant castables for circulating fluidized bed boilers use corundum, silicon carbide, and special grade bauxite as the main raw materials, with superfine powder and compound additives. It has the characteristics of high strength at early medium temperature, good high-temperature performance, stable volume, strong resistance to slag penetration and erosion, erosion resistance, convenient construction, and strong integrity of the lining structure. It is a good wear-resistant material currently used in CFB boilers.

High-strength wear-resistant castables for waste incinerators, low-aluminum mullite, and SiC are selected as aggregates, silica sol, and pure calcium aluminate cement are used as binders, and ultrafine powder and water reducer are added. The sample is mixed according to the ratio of aggregate and powder 67:33, the critical particle is 5mm, and the binder and water reducer are added to the powder. According to the principle of first coarse and then fine, pour it into a mixer, pre-mix for 3 to 5 minutes, then add an appropriate amount of water, stir for 3 minutes, take it out and pour it into the triple test mold, vibrate and shape, and cure, dry and fire.

High-strength Corundum Castable — High-strength Wear Resistance Castable

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Characteristic analysis of high-strength wear-resistant castable for a waste incinerator

The following characteristics of high-strength wear-resistant castables for waste incinerators are tested as a reference for the analysis.

Determine the fluidity of the castable;
Measure its physical and chemical indexes at room temperature after treatment at various temperatures, as well as alkali resistance and abrasion resistance;
The acid test is carried out according to the crucible erosion method to detect Cl2 erosion. The test was carried out at 1000 ℃ for 48 h, and humid acid Cl2 gas was introduced to analyze the corrosion surface changes and microstructure of the sample.
The effects of Al2O3/SiO2 value, binder addition, SiC addition, and superfine powder addition on the properties of the castable were studied, and the optimal addition amount was optimized.

The results show:

When the value of Al2O3/SiO2 in the castable is about 0.8, the acid and alkali corrosion resistance of the sample is the best;
Cement-silica sol compound addition and the addition amount is 5%, the effect is the best;
Wear-resistant castables added with SiC have higher drying strength. Although the intensity of medium temperature (1100 ℃) fluctuates, it also maintains a relatively high value. When used at around 1300°C, the oxidation resistance and wear resistance will be effectively improved;
When the addition amount exceeds 15%, due to the fineness of SiC, a continuous phase is formed in the matrix, which can significantly improve the thermal conductivity of the castable. So that the castable has better thermal shock resistance;
When a proper amount of silicon powder is added, the specific surface area of the silicon powder is large, the activity is higher, and the silicon powder has the effect of filling and promoting sintering. In this way, only a small amount of water is needed to make the castable have better rheology and improve the high-temperature strength of the castable.

Application of high-strength wear-resistant castables for a garbage incinerator

By analyzing the characteristics of high-strength wear-resistant refractory castables for tie incinerators, Rongsheng refractory manufacturers, combined with the actual working environment and operating temperature, developed high-strength wear-resistant castables for garbage incinerators. The high-strength wear-resistant castable is used in the garbage incinerator and is mainly used in the wear-resistant parts such as the hearth and the roof of the gasifier. Through many years of operation, no product quality problems occurred in the middle, and the garbage incinerator is operating in good condition. Another incinerator project also used Rongsheng’s high-strength wear-resistant castables. It has been in operation for nearly 2 years without any obvious damage.

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Rongsheng refractory castable manufacturer

Rongsheng is an experienced refractory castables manufacturer. Rongsheng’s refractories have served customers in more than 60 countries. Through continuous accumulation and research and development, Rongsheng has built a new unshaped refractory production line with an annual output of 80,000 tons. Provide high-quality unshaped refractory materials for Rongsheng customers. The Furnaces we serve covers CFB boilers, gasifier equipment in the chemical industry, etc. At the same time, Rongsheng specially developed refractory materials for garbage incinerators by studying the working characteristics of garbage incinerators. For more information about high-strength wear-resistant castables for waste incinerators, please contact us. We will provide you with services according to your specific needs.

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Jul 24 2020

Rongsheng Refractory Cement for Sale in Philippines

Refractory Cement for Sale is also called bauxite cement, high alumina cement, aluminate cement. According to the national standard GB201-2000, refractory cement is also collectively referred to as CA50 aluminate cement. In order to distinguish the strength of cement, such symbols are often used to indicate: CA50-A600, CA50-700, CA50-A900, etc. Refractory cement is a fast-setting, fast-hardening, high-strength high-temperature binder. The initial setting time is generally about 2 hours. The final setting time is generally about 4 hours. The strength can reach 70% within three days, and the strength can reach 100% of the overall strength within 28 days. Refractory cement, high alumina fine powder, high alumina aggregate, and other additives are formulated into refractory castables according to a certain particle gradation. Rongsheng Refractory Cement for Sale, Its refractory temperature can reach 1500 degrees Celsius, and it is widely used in high-temperature furnace engineering.

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Classification of Refractory Cement for Sale

Refractory cement is one of the main materials for making high-temperature furnace linings. It is Refractory Cement for Sale with refractoriness not lower than 1580°C. According to different compositions, it can be divided into aluminate refractory cement, low calcium aluminate refractory cement, calcium magnesium aluminate cement, and dolomite refractory cement.

Aluminate cement can be divided into four categories according to Al2O3 content:

CA-50, 50%≤Al2O3＜60%
CA-60, 60%≤Al2O3＜68%
CA-70, 60%≤Al2O3＜77%
CA-80, 77%≤Al2O3

The Main Components of Refractory Cement

Refractory cement refers to cement with calcium aluminate as the main component. Refractory Cement for Sale is the basic bonding agent of unshaped refractory-casting refractory. Its chemical composition is mainly Al2O3 and CaO, and some also contain quite a lot of Fe2O3 and SiO2. The mineral composition consists of the following three kinds of minerals, CaO·Al2O3 (CA), CaO·2Al2O3 (CA2), 12CaO·7Al2O3 (C12A7) three compounds. And it is composed of 2CaO·Al2O3·SiO2 (C2AS) containing inclusions and 4CaO·Al2O3·Fe2O3 (C4AF).

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Properties of Refractory Cement

The properties of Refractory Cement for Sale mainly depend on its mineral composition. The main mineral of refractory cement is monocalcium aluminate (CA), which has a high hydraulic activity and coagulates. Although it is not very fast, it hardens quickly, and the hardening time does not exceed one day. It is the main source of the strength of high alumina cement, especially the early strength. Calcium aluminate (CA2) has slower hydration and hardening, with lower early strength and higher late strength. the C12A7 has the characteristics of fast hydration and fast setting, but the strength is not high. In ordinary high alumina cement containing inclusions ( C2AS and C4AF), C4AS plays a role in hardening the cement as soon as possible. In high-grade high-alumina cement, C12A7 plays a hardening role. As for C2AS, basically it does not produce hydration, so it cannot show its strength.

Refractory cement contains 5 kinds of calcium aluminate minerals, and these calcium aluminates will show intense heat generation as the hydration reaction proceeds. Ordinary high-alumina cement contains 53-55% Al2O3. After 5-8 hours, the temperature reaches a peak value of 80-90℃. The high-alumina cement containing 70% Al2O3 will reach the peak temperature after 10-12h and the high-alumina cement containing 80% Al2O3 after 8-10h, which are 80 ℃ and 70 ℃ respectively.

The heating temperature and the time to reach the maximum temperature of a single cast of different types of high alumina cement are determined by the heating characteristics and content of the calcium aluminate contained.

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How to Use Refractory Cement

The use of refractory cement is very simple, it can harden after adding water and mixing. Generally, there is no need to add other binders, but some refractory aggregates and powders can be added. If only refractory cement is used, a lot of cracks will occur after high temperature. It can be used to cement various refractory aggregates, such as corundum, calcined high alumina bauxite, etc. It is made into the refractory mortar or refractory castable, which is used as lining of cement rotary kiln and other industrial kilns.

Precautions for Refractory Cement

Many people tend to confuse refractory cement with refractory soil. If refractory cement and refractory soil are used together, the use-value of refractory cement will be greatly reduced. It is equivalent to mixing refractory cement and loess together. The solidification strength and marking of refractory cement will be much lower. It is recommended that workers who have been engaged in furnace construction for a long time, in refractory construction, use refractory cement and refractory soil rigorously.

High Alumina Castable Refractory Cement — Rongsheng High Alumina Refractory Cement for Sale

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Refractory Cement for Sale Price

Because refractory cement has the following characteristics, the consideration of the Refractory Cement for Sale price also needs to be analyzed according to specific working conditions.

Refractory cement is a bonding agent used in thermal kilns or wall linings.
This type of cement is different from other types of cement, it still maintains a firm bond under high-temperature conditions.
Refractory cement will have a certain strength at room temperature, which is used to ensure the hardened shape of the preform.
In addition, refractory cement solidified at room temperature has some physical and chemical advantages. For example, through the cement solidification process, the internal moisture of the cement product can be quickly precipitated, or the internal structure can be tightly reinforced.

The price of commonly used refractory cement is generally 1800 yuan per ton. Some users need a small amount of refractory cement to make small furnaces, and the price at this time is calculated according to the price of each bag.

What is the price of refractory cement for boilers? There are also many types of refractory cement for boilers, mainly because of the different aluminum content. The general CA-50 is about 1500, the cheaper one can reach about 1200, and the most expensive CA-80 and 70 can reach 5 to 6 thousand tons. The refractory cement prices listed in this article come from the Internet and are for reference only. The specific price is subject to the price provided by the supplier at the time of purchase. Get more details on refractory cement Philippines for sale. Please leave us your requirements.

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Yearly Archives: 2020

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The role of high alumina refractory mortar additives

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The effect of cement addition on the performance of ladle Porous Plugs and well blocks

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Comparison of performance of chrome corundum Porous Plugs block and corundum-spinel Porous Plugs block

Performance Comparison of Chrome Corundum Brick and Corundum-Spinel Brick

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Rongsheng Kiln Refractory Material Manufacturer

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Alumina-Magnesia Brick and Alumina-Magnesia-Carbon Brick

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Resin-Bonded Alumina Magnesia Carbon Brick

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Magnesia Alumina Carbon Brick

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Rongsheng Refractory Brick Manufacturer

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Development of refractory materials for ladle lining

Application of Carbon-free Lining Materials

Corundum Spinel Bricks

High-performance Slag Line Magnesia Carbon Brick

Optimization of Permanent Layer Refractory Materials

Development Trend of Refractory Materials for Ladle Lining

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Several Different Types of “T” Refractory Bricks

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T19 Mullite Bricks

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Rongsheng Refractory Bricks Manufacturer

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Factors Affecting the Service Life of Corundum Bricks on the Tapping Channel

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Rongsheng Refractory Bricks Manufacturer

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Application of High-strength Wear-Resistant Castables

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Characteristic analysis of high-strength wear-resistant castable for a waste incinerator

Application of high-strength wear-resistant castables for a garbage incinerator

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Rongsheng refractory castable manufacturer

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Classification of Refractory Cement for Sale

The Main Components of Refractory Cement

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Properties of Refractory Cement

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How to Use Refractory Cement

Precautions for Refractory Cement

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Refractory Cement for Sale Price