Kiln Refractories Blog

Characteristics and Application of Mullite Bricks

December 9, 2019 KilnRefractory

Mullite Bricks and corundum mullite bricks have the advantages of high load softening temperature, low high-temperature creep rate, and good thermal shock resistance. Widely used in industrial furnaces such as blast furnace, hot blast furnace, glass melting furnace, dry quenching and heating furnace. Mullite Bricks are easily eroded by alkaline refractory bricks at high temperatures. In addition, at high temperatures, mullite can react with water vapor to form Al2O3 and be damaged. Contact RS Refractory Supplier for more.

Therefore, mullite refractory bricks are not suitable for long-term use in environments with high alkaline slag and high water vapor content.

In addition to mullite and its composite refractory bricks composed of corundum, mullite can also be used to form refractory bricks with other materials to improve its performance. Such as zircon mullite refractory brick, mullite-silicon carbide refractory brick and so on. Zircon mullite refractory brick is mullite-zirconia composite material. However, because zirconia is expensive, in actual production, zircon mullite clinker or refractory bricks are often prepared by reacting Al2O3 or alumina with zircon.

The manufacturing methods of such refractory bricks and raw materials include electric melting method and sintering method. Aluminum fused zirconium silicon (AZS) refractory bricks made by electrofusion have been discussed in fused zirconium corundum bricks. Zircon mullite clinker is prepared by calcining Al2O3 and ZrSiO4 ingredients, and then crushing, kneading, molding and firing to obtain zircon mullite refractory bricks, that is, sintered AZS brick.

corundum mullite bricks

Refractory bricks made with sintered or fused mullite as the main raw material can be all mullite, some can be mullite, and some are corundum. The former is called mullite refractory brick, and the latter is called corundum-mullite refractory brick or corundum mullite brick. The production process of mullite refractory bricks is the same as that of high-alumina bricks, and the ingredients are subjected to several processes such as mixing, forming, drying and firing. The firing temperature is related to the composition of ingredients, the purity of the raw materials and the requirements for the performance of the refractory bricks, which is usually 1500 to 1700 ° C.

The Mullite Bricks are mainly used for hot blast stove top, blast furnace body and bottom, glass melting furnace heat storage chamber, ceramic sintering kiln, dead angle lining of petroleum cracking system, etc. More info at website: https://kilnrefractory.com/.

Magnesia Brick for Sale

November 19, 2019November 19, 2019 KilnRefractory

The raw material of magnesia brick is mainly magnesite, and its basic component is MgCO3. After high temperature calcination, it is crushed to a certain particle size to become sintered magnesia. Magnesia is widely used as a material for repairing furnaces, beating materials, and magnesia containing less impurities (ω(CaO)<2.5%, ω(SiO2)<3.5%) as a raw material for the production of magnesia bricks. RS Supplier Magnesia Brick for Sale is with high quality and the other magnesia bricks, etc.

Raw Material of Magnesia Brick for Sale

Sintered magnesia is one of the important raw materials for magnesia refractory bricks such as magnesia brick. Sintered magnesia is obtained by calcining natural magnesite or light burnt magnesia in a rotary kiln or shaft kiln at a temperature range of 1500~2300 °C. The magnesia crystals are grown and densified to be converted into inert sintered magnesia, also known as calcined magnesia. Because magnesite ore has the phenomenon of parent salt during calcination, that is, the decomposition of magnesium carbonate forms a microcrystalline polymer of cubic magnesium, the crystal structure of the parent magnesite remains, which makes it difficult to further densify the magnesium oxide. Pure magnesite is to be sintered, and the calcination temperature should be above 2000 °C. The final sintering temperature of ordinary magnesite depends on the crystallization characteristics of the raw materials and the type and amount of impurities. Generally, sintering can be achieved at 1450~1700 °C.

In order to achieve sufficient sintering of magnesium oxide, a light-burning magnesia fine grinding method is generally used to destroy the imaginary lattice of lightly burned magnesia. The high-pressure molding and the improvement of the calcination temperature and the introduction of trace additives are used to eliminate the influence of the mother salt artifact and promote the densification of the calcined product.

Characteristics of Magnesia Bricks

Magnesia Brick for Sale is alkaline refractory and have strong resistance to alkaline slag. However, it cannot resist the corrosion of acidic slag. At 1600 ° C high temperature, it can react with silica brick, clay brick, and even high alumina brick. The refractoriness of magnesia bricks https://kilnrefractory.com/magnesium-bricks/ is above 2000 °C, but its load softening point is only 1500-1550 °C. Moreover, the temperature interval at which the deformation variable starts to soften to 40% is small, only 30 to 50 °C. The thermal stability of magnesia bricks is also poor, which is an important reason for the damage of magnesia bricks.

On the heating furnace and the soaking furnace. Magnesia bricks are mainly used for laying the bottom surface of the furnace and the lower part of the soaking furnace wall. It is resistant to corrosion by iron oxide scales. In order to improve the thermal stability and high temperature strength of the magnesia brick, a fine alumina powder is added to the furnish to form a magnesia-aluminum brick combined with magnesium spinel. Large furnaces can be successfully used as high temperature roof materials and for areas where the furnace has alkaline slag corrosion.

Magnesia Brick for Sale

The sintered magnesia brick is made of high-quality sintered magnesia as the main raw material, and the pulp is used as the binder. After kneading and high pressure molding, it is fired in a high temperature tunnel kiln at 1550 ° C or higher. https://kilnrefractory.com/magnesium-bricks/ Has good thermal stability, erosion resistance and flaking resistance. It is widely used in industrial furnaces such as converters and electric arc furnaces as refractory lining materials.

The fused magnesia brick has the advantages of compact brick structure, high mechanical strength and less impurity content. It is mainly used in the high temperature area of the regenerator of large glass kiln.

Magnesia refractories also include: magnesia-aluminum bricks, magnesia-chromium bricks, magnesia carbon bricks, magnesia-silica bricks, and the like.

Cautions of Magnesia Bricks

Magnesia bricks have poor hydration resistance, easy to hydrate with water, and cracks and reduce their strength. Therefore, pay attention to moisture, rain and snow during storage and transportation.

Magnesia Brick Manufacturer

RS is one Magnesia brick manufacturer, has been export to more than 60 countries. IF you are looking for the magnesia bricks as the refractory lining materials. Please Click: https://kilnrefractory.com/. Magnesia Brick for Sale.

Four Main Properties of Plastic Refractory

November 6, 2019 KilnRefractory

Plastic Refractory is mainly used as lining materials for various heating furnaces, soaking furnaces, annealing furnaces, sintering furnaces, and electric furnace roofs in the steel industry. The four main Properties of Plastic Refractory are as follows:

1, Thermal Shock Resistance
Compared with refractory bricks of the same material and other amorphous refractories, the plastics have a low bulk density and a large number of holes and microcracks inside. And when used in the heating process and high temperature, there will be no crystal form change and cause severe deformation. The mineral composition near the heating surface is mullite and cristobalite crystallites, and the glass phase is less. The physical properties of the structure and phase from the side facing the low temperature are tapered rather than violent. Therefore, the plastic refractory has better thermal shock resistance. Therefore, the plastic can be particularly suitable for furnace walls with high temperature fluctuations and high temperature furnace roofs subjected to flame impact or radiation.

2, Peeling Resistance
The castable has fewer voids than the plastic refractory, even after drying, the aggregate remains in close contact with the cement combination. The cement itself is very dense and fine, so the castable refractory should not be directly impacted by the flame, nor can it withstand the drastic changes in the furnace temperature. Otherwise, due to the sudden expansion of the aggregate, it will unavoidably lead to the collapse of the surrounding cement structure. This phenomenon is known as spalling of the casting lining. In plastic refractory, refractory clay acts as a binder, and the clay shrinks due to drying and dehydration, creating fine gaps around the aggregate. The relatively loose connection has the function of absorbing the sudden expansion of the aggregate. Due to this feature of plastic refractory, plastic refractory linings can be used under the following conditions:
(1) direct impact of the flame;
(2) high-intensity radiation that burns heat;
(3) A drastic change in the temperature of the furnace.

3, Corrosion Resistance
Refractories used at high temperatures are eroded by various gases and slags and react in various ways, causing changes in material properties and corrosion. The castable with high aluminum cement as the binder has lower acid and alkali corrosion resistance than plastic. Since plastic refractory can be used as a binder for refractory clay, plastics are generally resistant to acids and alkalis.

4, Wear Resistance
Ordinary plastic refractory, Because the aggregates are bonded together by refractory clay, the strength is not very high, so the wear resistance of the plastics is not very good, and the aggregates are easily detached when rubbed. Due to the compact and compact distribution of the cast lining surface and the exposed aggregate, the high alumina cement binder is protected from the impact of the dust by the aggregate to maintain its bonding force. The wear resistance of castables is usually significantly better than that of plastics. However, phosphate-bonded plastic refractory, whose fine particles maintain high bonding strength, can be used in friction linings under high temperature conditions. Since phosphate is a thermosetting binder, phosphate-bonded plastics require high strength after drying and baking after application.

Get More details about the Properties of Plastic Refractory, Please Contact RS Plastic Refractory Supplier, We will give you back as soon as possible!

High Quality Chrome Bricks

October 29, 2019 KilnRefractory

Chrome bricks are refractory material made of chrome ore with a chromium oxide content of more than 30%. In order to improve the high temperature performance of the brick, generally more than 10% of magnesia is added to the raw material.

Chrome bricks are neutral bricks. They have weak effects on acidic and alkaline refractories at high temperatures. Their load softening temperature and thermal shock resistance are lower than those of magnesia chrome brick. Chrome brick is mainly used for the isolation layer of acidic and alkaline refractories at high temperatures, and also for the lining of colored smelting furnaces, but it is not suitable for direct contact with molten iron and where the atmosphere changes frequently.

Chrome Bricks Application

Chromium oxide bricks (referred to as chrome bricks) were first used in non-ferrous metallurgical furnaces and gas slag furnaces, and have excellent corrosion resistance against furnace steel slag, colored smelting slag, coal gasifier slag and various glass liquids. In the past 10 years, this refractory material has been used in glass melting furnaces, but it is limited to dark-bottle glass melting furnaces or alkali-free glass fiber melting furnaces, and is mainly used in high temperature parts of glass melting furnaces. Such as: the upper pool wall, small furnace mouth, fluid hole, feeding port and so on. Because it can significantly extend the kiln age, it has caused widespread concern in the glass industry.

Mag Chrome Bricks

Magnesia-chrome brick is a refractory product containing magnesium oxide (MgO) and chromium oxide (Cr2O3) as the main components, and periclase and spinel are the main mineral components. This type of brick has high refractoriness, high temperature strength, strong resistance to alkaline slag, excellent thermal stability, and certain adaptability to acidic slag. The main raw materials for the manufacture of magnesia chrome bricks are sintered magnesia and chromite. The purity of the magnesia raw material should be as high as possible. The requirements for the chemical composition of the chromite ore are: Cr2O3: 30-45%, CaO: ≤ 1.0-1.5%.

Direct Combination of Magnesia Chrome Brick

Magnesia-chrome bricks are mainly used in metallurgical industries, such as the construction of open hearth furnace roofs, electric furnace tops, furnace refining furnaces, and various non-ferrous metal smelting furnaces. The high temperature part of the ultra high power electric furnace wall is cast and cast magnesia chrome brick. The high-erosion zone of the refining furnace outside the furnace is made of magnesia-chrome brick made of synthetic material. In the high-erosion area of the non-ferrous metal flash smelting furnace,magnesia chrome brick made of fused cast magnesia chrome bricks and synthetic materials are used. In addition, magnesia chrome bricks are also used in cement rotary kiln firing zones and glass kiln regenerators.

Aluminum chrome brick

Aluminum chrome bricks are based on corundum and chromium trioxide. It has low impurity content, stable high temperature chemical properties, high melting point, high hardness and high strength. Aluminum chromium has good corrosion resistance and thermal shock resistance, but the load softening temperature is lower due to higher impurity content.

Castable Refractory Mortar

October 23, 2019 KilnRefractory

The castable refractory mortar consists of refractory powder, binder and additive. Almost all refractory materials can be made into powders used to make refractory mortar. The particle size of the refractory mortar will vary according to the requirements of use. The ultimate particle size is generally less than 1 mm, and some are less than 0.5 mm or less.

Forming Method of Castable Refractory Mortar

Almost all refractory materials can be made into powders used to make castable refractory mortars.

The ordinary refractory mortar made of refractory clinker powder and appropriate amount of plastic clay as a binder and a plasticizer has a low room temperature strength and a high strength under the formation of a ceramic bond at a high temperature.

A chemically bonded refractory mortar using a hydraulic, gas-hard or thermosetting bonding material as a binder, hardens before a certain chemical reaction occurs before the ceramic bonding temperature is formed.

High Alumina Castable Refractory Mortars

Refractory Mortar Characteristics and Applications

Good plasticity and convenient construction;
Strong bonding strength and strong corrosion resistance;
High refractoriness, up to 1650 ° C ± 50 ° C;
Good resistance to slag invasion;
Good thermal exfoliation.
Bulk density: 1.8-2.2g/cm3.

The castable refractory mortar is mainly used in coke ovens, glass kiln furnaces, blast furnace hot blast stoves, and other industrial kiln furnaces. The applied industries are: metallurgy, building materials, machinery, petrochemical, glass, boiler, electricity, steel, cement, etc.

Refractory Mortar Selection

According to the material, refractory mortar can be divided into clay, high-aluminum, siliceous and magnesia refractory mortar. When selecting the material of the refractory mortar, it should be considered to be consistent with the material of the refractory product of the masonry. In addition to the crevice material, the castable refractory mortar can also be used as a protective coating for the lining by smearing or spraying.

Castable Refractory Mortar Manufacturer

Rongsheng is a manufacturer of refractory materials with rich experience in production and refractory lining construction. Our castable refractory production line is 150 tons per day, and our refractory brick products are also exported to 62 countries. And received the customer’s praise! Our refractory technology team provides custom refractory brick and castable products for a wide range of thermal equipment. Looking forward to your order and visit! Website: kilnrefractory.com

Casting Refractory Cement

October 16, 2019 KilnRefractory

Refractory castables are made of refractory cement (10%~15%, weight ratio) and refractory aggregates, so casting refractory cement is also an indispensable part.

The Role of Casting Refractory Cement

The role of casting refractory cement in refractory castables is the binder. It affects the setting time of the refractory castable. At the same time, due to the nature of the castable refractory cement itself, it also causes a series of performance degradation of the refractory castable.

Main Properties of Castable Refractory Cement and Its Effect on Refractory Castables

In order to completely hydrate the cement, excessive addition of water (10%~15%) is required to cause the ceramic refractory castable to have a high porosity and a decrease in density.
Calcium aluminate hydrate has strong dehydration and recrystallization effects in the middle temperature stage, which destroys the microstructure of the hard spots in the castable, and the strength of the refractory castables drops sharply in the middle temperature stage.
The cementitious binder brings more calcium into the castable, which leads to a decrease in the load-softening temperature of the ceramified refractory castable, and the thermal shock stability index deteriorates.

Low Cement Castables Properties

In view of the problem of poor high temperature performance of ordinary refractory castables, low cement refractory castables effectively avoid the regret of high temperature performance. The low-cement refractory castable, often mentioned, has a cement content of less than 8%, while less than 4% is called an ultra-low cement refractory castable.

In contrast, the deficiencies described above for conventional refractory castables translate into the advantages of low cement refractory castables. Its structure is dense. The apparent porosity is low, the refractoriness is high, the load softening temperature is high, the high temperature strength is high, and the thermal shock stability is good. However, due to its low cement content, the condensation time is long, and the early strength is low, which is particularly unfavorable in winter and low temperature conditions. Therefore, pay full attention when construction lining.

Casting Refractory Cement Manufacturer

As a manufacturer of refractory materials, Rongsheng is committed to the production and development of refractory bricks and refractory castables. It is designed to provide customers with refractory castable products that meet the needs of customers’ thermal equipment. Our casting refractory cement with low cement Can also help you more. Email to Us for free quote.

Steel Fiber Reinforced High Alumina Castables

October 8, 2019October 8, 2019 KilnRefractory

Steel fiber reinforced refractory castable, is the refractory castable made of refractory aggregate, powder, binder, admixture and steel fiber (heat resistant stainless steel fiber, generally 0.6%~2.5%). It has the characteristics of high strength, wear resistance and thermal shock resistance. Applicable to masonry at high temperatures with mechanical vibration, thermal shock, wear and other parts.

Steel Fiber Reinforced High Alumina Castables

Steel Fiber Reinforced Refractory Castable Application

It is widely used in the steel, metallurgy, chemical and building materials industries in boilers and furnace outlets, tops, side walls, etc.; in CFB boilers, it is often used in furnace outlets and side walls, top, cyclone separators. , cyclone separator top, return feeder and other parts.

Theoretical basis for steel fiber reinforcement

For general refractory materials, they are not wear-resistant during use, have poor seismic resistance, and are prone to cracking and crushing at high temperatures. The addition of steel fiber can greatly improve the strength and the cracking of the structure, thereby achieving the purpose of prolonging the service life of the furnace. The addition of steel fibers to the amorphous refractory material results in a significant improvement in refractory properties.

The main features of steel fiber as a refractory reinforcement

(1) The strength of steel fiber is very high. According to the composite material rule, the toughness, crack resistance and peeling resistance of steel fiber after adding steel fiber increase, which is beneficial to the overall improvement of tensile strength and bending strength of refractory material.

(2) In the steel fiber reinforced refractory material, since the steel fiber is present as a crack arresting expansion, it is intended to prepare a gradual expansion process of the microcrack generated in the refractory material under the action of thermal stress and mechanical stress.

(3) Due to the action of the steel fiber in the refractory material, even in the case of cracking of the refractory material, it can be carried, thereby improving the fracture work of the refractory material and finally increasing the plasticity of the refractory material. The fracture work of the steel fiber refractory is more than several times greater than that of the steel fiber refractory. Therefore, the steel fiber increases the shock resistance and mechanical shock resistance of the refractory material.

Compared with non-reinforced refractory castables, heat-resistant steel fiber reinforced high-aluminum castables have excellent toughness, high strength, good impact resistance and thermal shock resistance. They can be used in key areas to significantly improve the performance of refractory castables. Extend the service life of refractory products.

The use of steel fiber reinforced high-aluminum castables can reduce the number of furnace inspections, save refractory materials, and reduce furnace costs and furnace fuel. At the same time, the operating rate of the kiln was increased, the production time was increased, the output was increased, and obvious economic benefits were obtained.

Website: https://kilnrefractory.com

Knowing The Benefits Of Alumina Silica Brick

December 7, 2018 KilnRefractory

Alumina silica brick is a good choice while you are working with furnaces, kilns and other sorts of equipment that has to work with high heat applications. Regular bricks can’t handle high heat and you have to use special bricks to line your kilns and furnaces otherwise the bricks are not going to work. They will often crack plus they might ruin your furnace.

Alumina Silica Fire Bricks for Sale

Among the great things about alumina silica brick is it has high thermal conductivity. This means that Highaluminarefractory.com/alumina-silica-fire-brick-for-sale is going to be capable of withstand high heat without failing. The bricks may also save a little money mainly because they allow you to heat the kiln up faster which saves on utility costs. The less you spend for utilities, the greater money you may save. You can buy this kind of bricks from online search professional manufacturer.

The bricks in addition have a high compressive strength making them stronger than other bricks. This means they are likely to stay longer and do a more satisfactory job at protecting the furnace. The bricks will certainly last for a long time and they are equipped for various sorts of conditions, from corrosive conditions to hot conditions.

Alumina Silica Fire Bricks at Rongsheng

The bricks are made with the highest quality materials plus they are bound to endure for some time. The best way to have the lowest prices are to invest some time pricing the bricks from some different manufacturers. This can be the easiest method to have the lowest price. Ensure that you factor the shipping charges into the price also simply because they can increase the price tag on the bricks.

Alumina silica bricks work great in any sort of high heat application and they are gonna aid the prevention of your furnace from cracking and achieving other difficulties that may ruin your kiln and cost you cash. Get more information about high alumina refractory at https://www.highaluminarefractory.com.

Learn Some Great Benefits Of Phosphate Bonded High Alumina Bricks

December 1, 2018 KilnRefractory

Phosphate bonded high alumina bricks offers some unique advantages in comparison to other sorts of refractory products. The bricks themselves are manufactured from high alumina fireclay which has been bonded with phosphate.

One of many primary advantages linked to these phosphate bonded high alumina bricks is they have a superior thermal shock resistance. This means that they can be unlikely to get rid of if they are in contact with rapid modifications in temperature.

Phosphate Bonded High Alumina Bricks for Sale

Thermal shock occurs when various parts of a physical object expand or contract at a different rate because of temperature. Occasionally, the resulting strain might be significant enough which it causes the material to crack. Highaluminarefractory.com/phosphate-bonded-alumina-brick, however, has high thermal shock resistance, meaning that they may withstand rapid temperature changes without cracking or breaking.

These bricks may also be highly resistant against abrasion as well as chemical exposure. This is often essential in certain industrial applications. Oftentimes, refractory bricks are in contact with extreme conditions. Whereas other types of materials may be unable to withstand these conditions, the abrasion and chemical resistance of phosphate bonded high alumina bricks ensures they are a fantastic selection for most of these situations.

Phosphate Bonded High Alumina Bricks

In general, there are many benefits associated with phosphate bonded high alumina bricks. If you have an issue where these bricks may be useful, it can be worth being familiar with all the advantages that they have to offer. You really should reach out to high alumina refractory manufacturers who are experts in making these bricks to gather more details about the sorts of conditions that they may withstand.

This will give you a greater understanding of whether or not they are the right choice for the situation. Whenever you are coping with extreme conditions, you should choose the right materials. In many cases, these durable bricks may come to be the best option. Please visit this website https://highaluminarefractory.com to find more info.