Industrial Refractory Archives - RS Kiln Refractory Bricks

As environmental protection becomes increasingly stringent, the copper metallurgical industry is facing severe challenges. Today, there are two main copper metallurgical methods: the fire method and the wet method. Among them, the fire method plays a major role, and the lining is mainly made of alkaline refractory bricks.

There are many types of pyrometallurgical furnaces. At present, the main pyrometallurgical copper smelting equipment in the world includes flash furnaces, reverberatory furnaces, blast furnaces, Noranda furnaces, and ISA furnaces (Osmet furnaces). There are more than ten kinds of smelting equipment such as Vanukov furnaces, Mitsubishi furnaces, Tenient furnaces, electric furnaces, silver furnaces, and so on. Most processes have problems such as low production capacity, high cost, high energy consumption, and serious pollution. Seriously restricting the development of the copper metallurgical industry.

Legend: Outokumpu flash smelting furnace

Outokumpu Flash Smelting Furnace

Since the advent of Outokumpu in Finland in 1949, flash smelting has gradually replaced the reverberatory furnace and blast furnace through continuous improvement, improvement, and development. Today it has become a competitive smelting technology used in today’s copper metallurgy and is generally considered the standard clean copper smelting process.

Currently, more than 50% of global blister copper production is produced using this technology. Due to the mature flash smelting process, it has a high degree of automation, large production capacity, low energy consumption, and good environmental protection. At present, most of the newly built or renovated and expanded copper smelting enterprises in the world adopt the flash smelting process.

Flash Furnace Structure

Outokumpu flash smelting uses oxygen-rich air or hot air at 723~1273K as the oxidizing gas. A down-spray concentrate nozzle is installed at the top of the reaction tower. The dry concentrate and flux are sprayed into the reaction tower at high speed with oxygen-rich air or hot air and are suspended in the tower. During the downward movement of the material, an oxidation reaction occurs with the oxygen in the airflow, releasing a large amount of heat. The temperature in the reaction tower is maintained above 1673K. The material reacts rapidly (2~3s) at high temperatures, and the resulting melt settles into the sedimentation tank. Complete the matte-making and slag-making reactions, and carry out clarification and separation.

Refractory Materials for Outokumpu Flash Smelting Furnace

Outokumpu flash smelting furnace consists of a reaction tower, sedimentation tank, and rising flue. The operating temperature in the tower is 1400~1500℃. Its work is subject to high temperatures, chemical erosion, and charge erosion, and is easily damaged. Generally, alkaline refractory bricks are used.

The top of the tower is suspended and built with fired magnesia-chromium hanging bricks, with a thickness of about 400mm. The lining around the spray nozzle and burner can be integrally rammed with magnesia-chromium refractory ramming material with a Cr2O3 content of 20%. First, install the finned cooling water pipe on the furnace shell. Lay a 20mm thick insulation board or refractory fiber felt, and then pound the magnesia-chromium refractory ramming material layer. Finally, the working layer is built with cast magnesia chromium bricks. The working layer of the tower wall 1m close to the top of the tower is allowed to be built with fired magnesia chrome bricks. The materials and structure used on the top of the sedimentation tank are the same as those on the top of the tower.

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Water-cooled copper sleeves are installed in the slag line area of the pool wall to protect the lining body and are all built with fused magnesia-chromium bricks, while the remaining pool walls are built with fired magnesia-chromium bricks. The total thickness of the anti-arch furnace bottom of the sedimentation tank is about 1800mm. First, 20mm thick asbestos boards or insulation boards are laid against the furnace shell, and 3 layers of clay insulation bricks and 1 layer of clay bricks are laid vertically. Then pound a layer of magnesia-chromium refractory ramming material about 100mm thick. Then use fired magnesia-chromium refractory bricks to build the working layer. The rising flue is on the other side of the sedimentation tank and consists of side walls, sloping end walls, sloping tops, and flat tops. It is mainly built with ordinary fired magnesia chromium bricks.

The lining at the lower part of the inclined end wall is easily corroded, and water-cooled copper sleeves need to be buried to increase the service life. The lining body where the sedimentation tank vault meets the reaction tower and rising flue. Steel beams are used to bear the load and water-cooled copper sleeves with fins are installed, and the working layer is integrally poured with magnesia-chromium refractory castables. Its service life is much longer than that of bricks.

Under normal operating conditions, the service life of the refractory brick lining of a flash smelting furnace is generally 3 to 10 years. During this period, 1 to 3 medium and minor repairs are required.

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Industrial Refractory

Jun 9 2023

Alumina Bricks Manufacturing Process

Alumina brick is a high-performance refractory material whose main component is alumina (Al2O3). Usually, high-purity alumina is used as raw material, which is sintered at high temperatures. As a high-quality supplier of alumina refractory bricks, RS Alumina Bricks Factory can provide high-quality Alumina Bricks for high-temperature kiln lining. Contact us for free alumina bricks price.

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Alumina Bricks Properties

High-temperature stability. Alumina bricks can work stably for a long time at high temperatures, and their service temperature can reach about 1700°C.
Corrosion resistance. The main component of alumina bricks is alumina, which is not easily corroded by acids and alkalis.
High strength and high hardness. Alumina bricks have high hardness, high strength, and good compressive and flexural strength.
Wear resistance. Wear Resistance Alumina bricks have a smooth surface and are not easily worn, so they have good wear resistance.

Alumina Bricks Use

Alumina bricks have a wide range of application scenarios and are mainly used in various refractory equipment in harsh environments such as high temperature, high pressure, and corrosion. Such as blast furnaces in the metallurgical industry, steel smelting furnaces, aluminum electrolytic cells, etc. High-temperature reaction kettles and high-temperature drying furnaces in the chemical industry. Boilers, kilns, coal-fired gasifiers, etc. in the power industry. As well as cement kilns and glass kilns in the building materials industry. In addition, alumina bricks are widely used in scientific research, aerospace, nuclear industry, and other fields.

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Alumina Bricks Manufacturing Process

After years of accumulation of production and sales experience, RS Alumina Bricks Factory has a further understanding of the production process of alumina refractory bricks.

Selection of binders

The manufacture of high alumina bricks usually uses soft clay as a binder. The main function of clay in the batching is to improve the formability of the mud and to make the formed and dried green body have a certain strength. The added amount of clay powder in the batching is generally 5%. In order to produce volume-stable low-level high-alumina bricks, high-alumina bauxite powder can be used as a high-alumina binder. Or use high-alumina bauxite powder and clay powder in a predetermined ratio to prepare synthetic mullite as a binder, and a volume-stable high-alumina brick without secondary expansion can be obtained.

Determination of Particle Composition

The particle composition of high alumina bauxite clinker has an important influence on the forming operation, green body density, high alumina brick density, and strength. Therefore, determining a reasonable particle composition according to different molding methods is an important process factor to stabilize the process operation and improve the quality of high-alumina bricks.

The principle of determining particle gradation is to form a good bulk density, which has no adverse effect on the performance and appearance quality of high alumina bricks. For low-grade bricks, the volume expansion caused by the secondary mullite reaction should also be considered.

High alumina bricks usually use coarse, medium, and fine three-level ingredients. However, secondary or quaternary ingredients may also be used. When using three-level batching, the critical size of each particle size is coarse particle 3-0.5mm, medium particle 0.5-0.1mm, and fine powder <0.1mm.

Production practice shows that when determining the particle size, appropriately increasing the size and quantity of coarse particles can increase the bulk density of the mud, and it is easy to shape. During firing, due to the small specific surface area of large particles, the secondary mullite reaction around the material is weakened, which is beneficial to the sintering of the green body. In turn, the air-packing rate of high-alumina bricks is reduced, the softening temperature under load and compressive strength are improved, and the thermal stability is improved.

There is a limit to the enlargement of the particle size. If the size of the coarse particles increases to 4-5mm, the corners of the high alumina bricks and the uniformity of the structure will be affected, and the larger the clinker particles, the larger the particle segregation during the production process. Therefore, the maximum particle critical size should not be too large. The maximum critical particle size is preferably 3 mm.

The fine powder in the ingredients is beneficial to the sintering of the green body and the increase of the density of the high alumina brick. Adding an appropriate amount of fine powder can not only make the secondary mullite reaction that occurs during the firing of high-alumina bricks proceed in the fine powder. Prevent the green body from loosening due to the secondary mullite ratio reaction around the coarse particles. Moreover, the firing shrinkage caused by the sintering of the fine powder can weaken or offset the volume expansion caused by the secondary mullite reaction. It is advisable to add about 50% fine powder.

The intermediate particles in the ingredients have neither the skeleton effect of coarse particles nor the sintering effect of fine powder. In the production process, according to the specific conditions of production, the addition of intermediate particles is usually limited to a minimum amount. Generally speaking, the additional amount of intermediate particles is about 10%.

In short, to determine a reasonable particle ratio, it is necessary to consider the reasonable bulk density, limit the number of intermediate particles added, and also according to the different molding methods. The performance and requirements of high alumina bricks are used to determine the critical size and the number of particles added at all levels. In the general brick-making process, the upper limit of coarse particles is usually 2-3mm, and the addition amount is 40-45%. For special-shaped high alumina bricks, the upper limit of coarse particles can be reduced to 1-2mm. It is advisable to limit the addition of 1-0.1mm intermediate particles to 10-20%. The amount of fine powder <0.1mm added should be controlled at 40-50%.

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High Alumina Bricks Properties

High alumina bricks for steel manufacturing are made from a special grade of bauxite as the main raw material. Small amounts of white fused alumina and alumina powder are added. Shaped by high pressure, sintered at high temperature. The main mineral composition includes mullite and corundum, which have excellent high-temperature physical properties and chemical resistance. high alumina bricks properties, high alumina bricks have the advantages of small temperature creep, strong corrosion resistance, thermal shock resistance, and stability. It is suitable for large and medium-sized hot air stoves. High alumina bricks are mainly used in masonry blast furnaces, hot blast stoves, electric furnace roofs, blast furnaces, and rotary kiln linings. In addition, high alumina bricks are also widely used as open hearth regeneration inspection bricks, gating systems, nozzle bricks, and other plugs.

RS Alumina Bricks Factory has advanced production equipment and the support of a strong technical team, and strives for excellence in the production of aluminum bricks. It aims to provide high-quality refractory products for customers’ high-temperature kiln linings to save production costs. At the same time, our customer service runs through the entire service life of our refractory bricks in the kiln lining. To choose an aluminum brick manufacturer, you must choose a manufacturer with strength and guaranteed customer service. In addition to our customer service, we also provide the design and construction of refractory lining solutions. Contact us for free quotes and samples.

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Industrial Refractory Steel industry refractories

Jan 12 2023

Cordierite Bricks for Hot Stove Burners

The hot blast stove burner is a device that mixes gas and air and sends them into combustion. The burner used in the hot blast stove is divided into two types: metal material and ceramic material. Among them, the ceramic burner is mainly made of mullite or cordierite-mullite refractory materials. The lining refractory material of the hot blast stove and its construction quality will directly affect the thermal insulation effect of the furnace body and the stability of the furnace lining structure, thus having a profound impact on the life of the furnace body and design efficiency.

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Brief Introduction of Cordierite Mullite Bricks

Friends who have not been in contact with cordierite mullite bricks will be very unfamiliar with this refractory brick. Today, Rongsheng Factory will introduce the product knowledge of cordierite mullite bricks to you, hoping to provide help to friends who need refractory bricks for ceramic burners in hot air stoves.

Cordierite mullite brick is a novel refractory material in the 1980s. It has the characteristics of high refractoriness, good thermal shock resistance, high load softening temperature, small expansion coefficient, and long service life. Cordierite mullite bricks are widely used in the light industrial ceramics industry, tunnel kiln car bricks, raceway kilns, pusher kilns, pusher kiln furniture, saggers of various specifications, etc. It is also suitable for kiln car surfaces in the ceramic industry, porous kiln push plates, roller kiln gaskets, and sagger for ceramics. It replaces clay refractory materials and high alumina refractory materials. It works well.

Cordierite Bricks for Ceramic Burner of Hot Stove

A burner is a device used to mix gas and air and send them into the combustion chamber. It is generally required to have sufficient combustion capacity, which is beneficial to shorten the burning period. It is necessary to ensure that the gas and air are mixed evenly and can be burned stably to avoid back spraying.

In order to improve the combustion capacity and meet the needs of high wind temperatures, ceramic burners are used. The ceramic burner is a burner made of refractory materials and installed in the combustion chamber. Gas and air pass through a special structure before combustion so that the airflow is divided into small streams (called trickle segmentation), mixed with each other after spraying out, and then burned in the room. Obviously, from the function of the ceramic burner, its working environment is subjected to the thermal shock of the sharp temperature change during the heat exchange process. Taking a steel factory as an example, each blast furnace has 4 hot blast stoves for the hot blast. When the hot blast stove is in normal production, it takes 35 minutes to heat up and 45 minutes to supply air. The brick temperature fluctuates from 500-600°C to as high as 1000°C at the moment when the ceramic burner starts to burn after the air is supplied. The thermal shock to refractory bricks is obvious. In addition, it is also impacted by combustion gas, so the corresponding refractory material should have better thermal shock resistance.

If the hot blast stove is an external combustion type. Traditional bricks for ceramic burners are cordierite bricks, but now they have been developed to use andalusite-mullite refractory bricks materials, high alumina cordierite bricks, mullite cordierite bricks, etc.

If it is a top-fired hot blast stove, the air temperature of the ceramic burner is relatively high (about 1360°C). Higher thermal shock resistance is required, which is reflected in the test conditions and the number of thermal shock stability. Originally required 1300°C, water cooling now requires 1100°C, and water cooling, thermal shock stability is not less than 100 times. The production of these bricks also uses three-stone minerals, especially andalusite minerals.

Rongsheng Refractory Bricks Prices — Rongsheng Refractory Bricks Manufacturer

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Rongsheng Refractory Brick Manufacturer

The cordierite bricks for hot blast stove burners produced by Rongsheng refractory brick manufacturers have good thermal stability and a small thermal expansion coefficient. Based on the principle of being responsible to customers, Rongsheng manufacturers strictly control the production standards of refractory products. To ensure that the produced refractory cement, refractory bricks, castables, and other products can have good high-temperature resistance and strong slag resistance. It can meet the operating temperature of the customer’s actual boiler. The product quality has been well received and supported by new and old customers. Buy cordierite bricks, cordierite mullite bricks, mullite refractory bricks, factory direct sales, and refractory materials at reasonable prices. Welcome to consult and purchase, Rongsheng refractory products and customer service will not let you down.

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Ceramics Refractories

Oct 9 2022

Application of Cordierite Mullite in Kiln Furniture

The cordierite matrix in cordierite-mullite kiln furniture endows the refractory with a low coefficient of thermal expansion and good thermal shock resistance. The low-aluminum mullite particles in the cordierite-mullite kiln furniture endow the material with a certain high-temperature resistance and volume stability under thermal conditions. Cordierite-mullite only contains oxides with stable valence, which will not pollute ceramic products due to oxidation-reduction problems. Therefore, cordierite-mullite refractory materials are often used to make refractory products such as shed plates, backing plates, and supports of ceramic kilns. What are the characteristics of cordierite-mullite kiln furniture?

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Cordierite Mullite Kiln Furniture

Primary kiln furniture refers to refractory products such as shed slabs and pillars for building the firing space. Secondary kiln furniture refers to the small kiln furniture placed on the primary kiln furniture directly used to support or protect the products to be fired. In addition to primary kiln furniture, cordierite-mullite materials include secondary kiln furniture of various complexities and shapes.

Application of Cordierite Mullite in Kiln Furniture

Cordierite-mullite has good high-temperature properties such as thermal expansion and thermal shock stability. Cordierite-mullite composites are widely used.

Kiln furniture is a special-shaped refractory material that supports and protects the firing process of ceramic products and magnetic materials. It has an extremely important impact on the quality of ceramic products and the energy consumption of the ceramic industry, mainly including saggars, shed plates, pad cakes, columns, and push plates. The performance of kiln furniture directly affects the quality and production cost of fired objects such as ceramics. General kiln furniture materials should have the following basic properties: high refractoriness, good thermal shock resistance, and chemical stability; high strength at room temperature and high temperature. Because one of the functions of kiln furniture is to bear the load, it must withstand the load of the product and the kiln furniture itself. High-strength kiln furniture materials can make kiln furniture light and thin, so as to increase the density of the kiln and improve the quality of products. In addition, it is also required to have good thermal conductivity and low thermal storage, regular appearance, and precise dimensions.

The cordierite material has the characteristics of a small thermal expansion coefficient and excellent thermal shock resistance and is widely used in ceramic kiln furniture by domestic and foreign manufacturers. The thermal shock resistance of kiln furniture is a key parameter that determines the life of kiln furniture. When the main material is determined, the thermal shock resistance of kiln furniture must be improved from its microstructure. So that it has high elastic modulus, fracture surface energy and thermal conductivity, low thermal expansion coefficient, and so on. Improved thermal shock resistance can be achieved by reducing thermal stress caused by thermal expansion, forming microcrack networks, and introducing energy dissipation mechanisms during inter-particle interface fracture. The thermal shock resistance of cordierite kiln furniture can be further improved by doping andalusite to introduce the energy dissipation mechanism during interface fracture.

Although cordierite has a small thermal expansion coefficient and good thermal stability, it has a low softening temperature under load and a small operating temperature range. Although products such as mullite and silicon carbide have good high-temperature performance, their cost is high. Using the mullite effect of andalusite at high temperatures, by adding SiC and a small amount of artificial mullite, the organizational structure of cordierite ceramic kiln furniture materials can be significantly changed. Improve high-temperature performance and reduce the cost of kiln furniture materials. Cordierite and cordierite-mullite kiln furniture structure is a ring-shaped silicate. Since the tetrahedrons in the structure are connected into a special helical six-membered ring, there are large gaps in the structure. When the particle is heated, it can vibrate to the gap, so the cordierite kiln has the characteristics of a small thermal expansion coefficient and excellent thermal shock resistance. However, cordierite is an unstable compound that decomposes into mullite and glassy phases. And the firing temperature range is narrow, and the high-temperature performance is poor. The mullite material has high refractoriness and good high-temperature stability. The mismatch between the thermal expansion coefficients of cordierite and mullite results in the formation of micro-cracks at the two-phase interface, which makes the material have excellent thermal shock resistance and good high-temperature performance. Therefore, cordierite-mullite composite materials are widely used in high-grade ceramic kiln furniture at home and abroad.

With the transformation of the firing technology of the ceramic industry from the traditional saggar firing to the open flame saggarless firing technology, the demand for high-quality ceramic kiln furniture materials – shed slabs is increasing. As one of the special kiln furniture for supporting porcelain pieces shed plate has always been an important auxiliary material in the ceramic industry. The material is mostly cordierite-mullite composite material with good thermal shock resistance and high-temperature performance. The cordierite-mullite slab is sintered from mullite and cordierite. The mechanism is that cordierite has a much smaller thermal expansion coefficient than mullite due to the large voids in the ring structure of cordierite. The expansion coefficients of the two are matched, so that micro-cracks are formed at the interface of the two phases, preventing the propagation of destructive cracks. Thereby, the thermal stability performance of the cordierite-mullite shed plate is greatly improved.

High alumina refractory products containing cordierite, it is made of high alumina raw material, synthetic cordierite, and binder. The thermal shock stability of the product is very good, and it can be used as ceramic kiln furniture, heat exchanger, catalyst carrier (honeycomb ceramic) for purifying waste gas, etc. For a free quote on cordierite bricks, please contact us.

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Industrial Refractory

Jun 30 2022

Corundum Mullite Bricks Used in the Burner of the Sleeve Lime Kiln

Generally, the burner of the sleeve lime kiln is made of magnesia refractory bricks. However, due to the fact that it is prone to breakage within a year of use, the service life of the burner brick is not synchronized with the service life of the kiln body. The burner brick of the sleeve lime kiln broke 1/3 in less than one year, and the service life of the lime kiln was more than 3 years. Therefore, the service life of the burner brick is not synchronized with the service life of the kiln body. Although the fracture of burner bricks does not affect the use of lime kilns, it has certain negative effects on the calcination process. Therefore, it is necessary to study the corundum mullite bricks used in the burner of the sleeve lime kiln.

The reason why the burner brick is easy to break is that the burner brick is made of magnesia refractory brick. In addition to excellent high-temperature resistance and lime resistance, the alkaline material also has the following unfavorable factors, which may lead to premature fracture.

Magnesium refractory has large thermal expansion and poor thermal shock resistance. The burner brick is scoured by the hot air flow of the flame, the thermal shock environment is harsh, and cracks caused by thermal shock are prone to occur.
Due to the large thermal expansion coefficient, the thermal stress of the magnesia refractory is high. When there is a local stress concentration, the fracture is easy to occur.
Magnesium refractories are easy to hydrate, resulting in bulging and cracking. Construction is greatly affected by environmental conditions. Improper baking is also prone to cracking, resulting in falling blocks. In cold and humid weather, the water in the fire mud is not easy to remove, and it is easier to hydrate the bricks. Therefore, it has strict requirements on construction environmental conditions and baking.
The thermal strength of magnesia refractories is low, and it is prone to creep under thermal stress.

Corundum Mullite Bricks Used in the Burner of the Sleeve Lime Kiln

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The improvement of burner brick material selection of burner brick prefabricated parts made of corundum mullite refractory castable has the following advantages.

The main crystal phase of corundum mullite refractory castable is corundum and mullite. Corundum has a high melting point of 2050°C, its hardness and strength can resist high temperature and airflow erosion, and it has excellent high temperature wear resistance. The melting point of mullite is also higher than 1840 ° C, which is characterized by a small thermal expansion coefficient and a needle-column mosaic structure, which has good thermal shock resistance. The refractory castable composite of corundum phase and mullite phase has the advantages of both, which can effectively resist the erosion of the burner brick by the hot air flow of the flame. At the same time, it can withstand the harsh thermal shock environment and prevent the burner brick from breaking.
Corundum mullite refractory castables do not have hydration problems. The construction is less affected by the environment, and the requirements for construction conditions are not harsh. And pouring, curing, and heat treatment can be carried out by the supplier, and the quality can be easily guaranteed. No hydration cracking during construction and baking.
The burner brick is a special-shaped brick, which is not easy to be machine-pressed. Using the casting method, it is easy to form integral or separate parts and to achieve precise control of shape and size. The critical particle size of machine-pressed bricks is limited, generally 5 mm. The critical particle size of the castable can be as large as about 20 mm, which is conducive to the stability of the structure and the improvement of thermal shock resistance.
When the burner brick is in use, since the gas (or fuel oil) is sprayed into the furnace, the CaO dust in the furnace is not easy to adhere to the burner cavity, and the reaction between CaO and the Al2O3-SiO2 material will not occur. Even if there is a small amount of CaO attached to the burner brick, the content of A12O3 in the burner brick is relatively high (greater than 75%), while the content of SiO2 and CaO is relatively low. According to the A12O3-SiO2-CaO ternary phase diagram, the reaction temperature is around 1500℃. It can be considered that the solid-phase reaction of Al2O3-SiO2-CaO does not easily occur at the working temperature of the lime kiln.

Summary: Through the analysis of the reasons for the phenomenon that the burner of the sleeve kiln is easy to break, and according to the combustion process of the lime kiln calcination zone, the structural design of the lining refractory material, etc. Production of corundum mullite refractory castable prefabs suitable for sleeve kiln burners. The corundum mullite bricks used in the burner of the sleeve lime kiln can synchronize the service life of the burner brick with the service life of the kiln body.

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Steel industry refractories

Jun 9 2022

Refractories for Sponge Iron Production by Direct Reduction Method for Sale

The main products produced by the direct reduction method are solid sponge iron, iron granules, and liquid pig iron. Among them, the production method of sponge iron is the most mature and has the largest output. The production of sponge iron mainly uses iron concentrates, iron oxide scales, and other raw materials with high iron oxide content, which are reduced to metallic iron under the action of reducing media. The reaction is a solid-phase reaction and emits a lot of gas. There are many pores in the generated solid iron, like a sponge, so it is called sponge iron. The reaction temperature is generally between 800 and 1300°C. The reducing media used are mainly non-coke reducing agents such as coal, natural gas, and coal gas. The equipment used in the production of sponge iron by the direct reduction method mainly includes a shaft kiln, square kiln, annular kiln, rotary kiln, tunnel kiln, and continuous furnace at the bottom of the trolley, etc.

Production of Sponge Iron by Shaft Kiln

It uses natural gas and steam to produce reducing gas, and then reducing gas reduces iron ore into sponge iron in a shaft furnace. The production process of HYL III sponge iron can be divided into two parts, the gas-making boundary area, and the reduction boundary area. The gas production boundary includes the generation and purification of reducing gas. The reduction boundary includes heating of reducing gas and reduction of iron ore. In the gas production boundary zone, steam and natural gas are mixed and then catalytically cracked in the reformer to produce synthesis gas mainly composed of hydrogen and carbon monoxide, which is dehydrated and sent to the reduction boundary zone. The cracking reaction is:

CH4 + H2O = CO + 3H2

CO + H2O = CO 2 + H2

In the reduction boundary area, after dehydration and decarbonation of the shaft furnace top gas, it is mixed with the gas from the gas production boundary area to form a reduction gas and enters the reduction gas heating furnace together. The heated reducing gas enters the furnace from the bottom of the reduction section of the shaft furnace and flows from bottom to top. Iron ore is added from the top of the shaft furnace and moves from top to bottom. The reducing gas and iron ore undergo a chemical reaction in reverse motion to produce sponge iron. Among them, the chemical reactions that take place are:

3CO + Fe2O 3 = 2Fe + 3CO 2

3H2 + Fe2O 3 = 2Fe + 3H2O

Process for Producing Sponge Iron in Tunnel Kiln

A tunnel kiln is a modern continuous firing thermal equipment, which is widely used in the roasting production of medium sponge iron in the metallurgical industry. It can also be used in other industries such as refractory production. The reason why the tunnel kiln has a wide range of industrial applications is inseparable from its stable firing system.

The tunnel kiln for firing sponge iron is a low-temperature kiln with a temperature range of 1000~1350℃. The heat source is clean energy natural gas, and the sponge iron reduction tank is transported by a kiln car for production reduction through a tunnel kiln. Tunnel kiln firing sponge iron is mainly divided into preheating zone, firing zone, and cooling zone. The temperature of these three parts can often be kept within a certain range. Therefore, the quality of the fired product is better.

Rotary Kiln for Producing Sponge Iron

The rotary kiln method, also known as the “SL/RN” method, uses solid fuel as a reducing agent and a rotary kiln as a reactor. The reducing agent and pellets (pig iron or pellets after oxidative roasting consolidation) simultaneously enter the rotary kiln for reduction roasting. The resulting sponge iron generally has a metallization degree of more than 90% and a particle size of 5 to 15 mm, which is usually used as a steelmaking raw material.

The working principle of the rotary kiln is to produce sponge iron. The raw material composed of solid carbon and ore particles (pellets) moves in the rotary kiln with the inclined furnace body and advances continuously. During the movement, the charge is preheated (<800°C region) and reduced (900-1000°C region) by the gas generated by the countercurrent or cocurrent combustion, and finally the product solid sponge iron is obtained.

Requirements for the Refractory Materials for Sponge Iron Production by direct reduction

At present, the sponge iron produced by shaft kilns with natural gas as the reducing medium in the world mainly accounts for about 80%. No matter what kind of kiln, the operating temperature is not high. Therefore, generally, aluminum-silicon-based refractories can meet the temperature requirements as kiln linings. However, it should be noted that Fe2O3 in the refractory material will be reduced to metallic iron and Fe3C under CO atmosphere conditions. The presence of Fe3C will promote the deposition of carbon, resulting in embrittlement cracking of the refractory. Therefore, in order to improve the service life of the furnace lining of the equipment, the Fe2O3 content in the refractory material should be reduced, and the structure of the selected material should be dense and the pores should be fine.

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Rongsheng Refractory Manufacturer

Rongsheng is a refractory manufacturer with rich production and sales experience. Rongsheng’s refractory products have been sold to more than 70 countries around the world, such as South Africa, Philippines, Chile, Malaysia, Indonesia, Vietnam, Kuwait, Turkey, Zambia, Peru, Mexico, Qatar, Egypt, Russia, Kazakhstan, etc. . In solving the problem of refractory lining materials for industrial furnaces, we have also accumulated many cases and solutions for thermal furnaces of customers. If your thermal kiln needs refractory lining materials, please contact us to purchase refractory materials for the production of sponge iron kilns. It is best to attach the working conditions of your refractory kiln, the working environment of the refractory lining, the working temperature, erosion conditions, etc. Based on the information you provide, we will recommend the most suitable refractory for your production needs. In order to reduce the number of furnace shutdowns and repairs, improve production efficiency and increase production efficiency.

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Industrial Refractory

Apr 19 2022

Refractory for Smelting Ferrosilicon Furnace

Ferrosilicon furnace, also known as electric arc furnace or resistance electric furnace, is a kind of submerged arc furnace, which is an industrial electric furnace with huge power consumption. The ferrosilicon furnace is a type of high energy consumption furnace, which reduces energy consumption and increases output so that the life of the furnace can be used for a long time. Only in this way can the production cost of the enterprise be reduced and the discharge of waste residue pollutants be reduced. Therefore, its requirements for refractory materials in use are also quite strict, as is the refractory factory.

The Working Characteristics of Ferrosilicon Furnace

Ferrosilicon furnace is mainly composed of a furnace shell, furnace cover, furnace lining, short net, water cooling system, smoke exhaust system, dust removal system, electrode shell, electrode pressing and lifting system, loading and unloading system, controller, burn-through hydraulic system, transformer, and various electrical equipment. Ferrosilicon furnace is mainly used for reducing and smelting ore, carbonaceous reducing agent and solvent, and other raw materials. Production of ferrosilicon, ferromanganese, ferrochromium, ferrotungsten, silicon-manganese alloy, calcium carbide, and other ferroalloys and chemical raw materials. Its working characteristic is to use carbonaceous or magnesia refractory material as furnace lining and use self-cultivation graphite electrodes. An industrial electric furnace with continuous feeding and intermittent tapping of iron slag.

Refractory for Smelting Ferrosilicon Furnace

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Refractory Lining Materials for Smelting Ferrosilicon Furnace

Different reaction temperatures of ferrosilicon furnaces, the use of refractory materials of different refractory lining materials in kilns. This scheme is for reference only. The specific kiln lining material to be used needs to be judged only after the technician understands the use of the ferrosilicon furnace.

New material preheating zone. The uppermost layer is about 500mm, and the temperature is 500℃-1000℃. The difference in heat comes from high-temperature airflow, electrode conduction heat and surface charge combustion, and charge distribution current resistance heat. The temperature of this part is different, and the kiln lining material is made of clay bricks.

preheat zone. After the water evaporates, the charge will gradually go down and make initial changes in the preheating zone. Silica transforms, expands in volume, and then cracks or bursts. The temperature in this section is around 1300°C. Built with high alumina bricks.

Sintering zone. It is the crucible shell, the temperature is 1500℃-1700℃. Liquid silicon and iron are formed and dropped into the molten pool. The sintering and air permeability of the charge is poor, the block should be broken, the gas ventilation should be restored, and the resistance should be increased. This area is hot and aggressive. It is built with semi-graphite-silicon carbide bricks.

reduction reaction zone. A large number of intense chemical reaction zones for materials, and the temperature of the crucible zone is 1750℃-2000℃. The lower part is connected to the arc cavity, mainly for the decomposition of SIC, the generation of ferrosilicon, and the reaction of liquid Si2O with C and Si. The high-temperature area must be built with semi-graphite-fired carbon bricks.

Arc zone. In the cavity area at the bottom of the electrode, the temperature is above 2000°C. The temperature of this zone is the highest temperature zone in the whole furnace, and it is also the source of the most temperature distribution in the whole furnace body. Therefore, when the electrode is inserted shallowly, the high-temperature area moves up, the temperature of the furnace bottom is low, and the slag is less removed, forming a false furnace bottom. As a result, the tap hole is moved up, and a certain false bottom has certain benefits for protecting the furnace. Generally speaking, the depth of electrode insertion has a lot to do with the diameter of the electrode. The general insertion depth should be kept at an extreme distance of 400mm-500mm from the bottom of the furnace. This part has a higher temperature and is built with semi-graphite-fired carbon bricks.

Phosphate concrete or clay bricks are used for permanent layers. The furnace door can be cast with corundum castables or pre-laid with silicon carbide bricks.

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In short, according to the furnace size, temperature, and erosion degree of the ferrosilicon furnace, choose suitable, environmentally friendly, refractory bricks and castables of different materials for the kiln lining. To buy refractory kiln lining material in kilns, please choose a strong refractory material manufacturer. As a refractory factory, Rongsheng refractory manufacturer has an advanced refractory production line and a professional technical team. Rongsheng Refractory Factory provides high-quality refractory kiln lining materials for industrial furnace refractory kiln linings to meet production requirements and save production costs.

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Ceramics Refractories

Apr 1 2021

Modern Ceramic Kiln Refractories Manufacturer

In modern ceramic kilns, as important structural materials such as beams and columns, it is required to have good high-temperature resistance, thermal shock resistance, and creep resistance. As a shed, it is mainly required not to pollute ceramic products, and secondly, it is required to have good creep resistance, thermal shock resistance, and high strength properties. As a manufacturer of high-quality refractory materials for ceramic kilns, the Rongsheng manufacturer provides reliable refractory lining materials for ceramic kiln refractory linings.

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Refractory Materials for Modern Ceramic Kilns

Therefore, silicon carbide is selected for the production of important supporting materials such as beams and columns due to its high strength, high thermal conductivity, and high thermal shock resistance. However, silicon carbide may cause some transition metal ions to undergo oxidation-reduction reactions and contaminate ceramics. Generally, oxide materials are not prone to oxidation-reduction reactions. Therefore, cordierite-mullite is selected for the production of low-stress kiln furniture materials such as slabs and backing plates for low-temperature fast-fired kilns due to its good thermal shock resistance. The mullite-corundum material is selected as the kiln furniture material for high-temperature ceramic kilns because of its good high-temperature resistance and creeps resistance.

A kiln or stove refers to a stove used to burn ceramic objects and sculptures or to fuse enamel on the surface of metal objects. It is generally made of bricks and stones. It can be made into various sizes according to needs and can be operated with combustible gas, oil, or electricity. Electric kilns are easier to control the temperature than kilns that use combustible gas and oil, but some potters and sculptors believe that the temperature of electric kilns rises too fast. (When the temperature in the furnace chamber is measured with a pyrometer (PYROMETER) or a temperature measuring cone (PYROMETRIC CONES), it can be seen through a peephole.)

Heavy Refractory Materials for Ceramic Kilns

The earliest refractory materials used in ceramic kilns were mainly heavy refractory bricks. With the continuous improvement of light insulation refractory materials, heavy bricks are basically used in the refractory lining of tunnel kilns, track kilns, and other kilns of building sanitary ceramics. Unless there are special needs, it is no longer used. Heavy refractory materials are still used in corrosion-resistant kilns, such as frit kilns, shuttle kilns for pigments, and rotary kilns. The purpose is to avoid slag drop and good corrosion resistance. Especially in frit kilns, where the materials are in direct contact with refractory materials, heavy refractory materials should be carefully selected, especially in terms of material, density, and thermal conductivity. The characteristics of this type of kiln are just the opposite of those of tunnel kilns and track kilns. Generally, heavy-duty refractory materials are in the inner layer, while medium-quality refractory materials and insulation materials are in the middle and outer layers.

The heavy refractory materials used in ceramic kilns are similar to those in the glass industry, mainly acid refractory bricks, neutral refractory bricks, and some special refractory bricks. The basis for selecting bricks is mainly determined by the firing temperature of the kiln, the atmosphere, the corrosiveness of the molten material, and the acidity and alkalinity.

What are the Insulation Materials Used in Ceramic Kilns?

The classification of ceramic kilns is very wide. There are differences in shape, heating method, and firing temperature, but they require a lot of insulation materials. Mullite insulation bricks are needed on the inner wall and backing of the hot surface of the kiln. Because of low thermal conductivity, high-temperature resistance, good stability, fine size, it can be processed into various shapes. Therefore, it is suitable for the thermal insulation of the roof, body, and bottom of industrial kilns, and the appearance is beautiful.

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(1) Mullite insulation brick

Lightweight mullite bricks, also known as mullite lightweight insulation bricks, are high-quality high-purity refractory powders. According to the specific gravity of the product, it is a lightweight mullite product synthesized by adding organic compound fillers, vacuum extrusion molding, and high-temperature sintering. It is suitable for the hot surface lining and backing of various industrial furnaces in metallurgy, petrochemical, building materials, ceramics, machinery, and other industries. It has the advantages of low thermal conductivity, low heat capacity, high purity, and low impurity content.

(2) Thermal insulation cotton

The thermal insulation cotton is white in color and regular in size. It integrates the functions of fire resistance, heat insulation, and heat preservation, and does not contain any binder. It can maintain good tensile strength, toughness, and fiber structure when used in a neutral and oxidizing atmosphere. The product has low heat capacity, low thermal conductivity, excellent thermal stability, no chalking within the use temperature, and excellent sound absorption and heat insulation properties. It is suitable for industrial kiln wall lining, backing material, high-temperature pipe insulation, kiln masonry expansion joint, furnace door, etc.

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(3) Ceramic fiber module

The ceramic fiber module is made of a ceramic fiber needle-punched blanket of corresponding material and processed on a special machine according to the structure and size of the fiber component. Its elasticity can compensate for the deformation of the furnace shell so that there is no gap between the components. The elastic fiber blanket can resist mechanical external forces. Because of its lightweight, it has less heat storage when used as a thermal insulation material, and low thermal conductivity brings a high energy-saving effect and has the ability to resist thermal shock.

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(4) Corundum heat storage refractory ball

Refractory balls are made of industrial alumina and refractory kaolin as main raw materials through scientific formula, forming, and high-temperature calcination. Mainly play the role of heat storage. The air volume entering the regenerator passes through the heat transfer of the regenerator, and the temperature rises sharply to hundreds of degrees or even thousands of degrees. The spherical heat storage body has the advantages of good thermal shock stability, large heat storage, high strength, easy cleaning, and reusability.

Rongsheng Refractory Materials for Sale for Ceramic Kilns

Rongsheng is an experienced refractory material manufacturer and sales company. Rongsheng’s refractory products 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. To purchase high-quality refractory materials for ceramic kilns, please choose Rongsheng refractory manufacturers. Because the refractory lining materials are purchased directly from refractory manufacturers, the price is cheap and the quality is guaranteed. The refractory manufacturers with guaranteed strength in the company can also guarantee the after-sales service of their products. Rongsheng sells refractory materials for ceramic kilns, and we look forward to cooperating with you.

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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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Category Archives: Industrial Refractory

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Characteristics of Refractory Materials for Hazardous Waste Incineration Rotary Kiln

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Corrosion of Refractory Materials in Hazardous Waste Rotary Kiln

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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

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Rongsheng Kiln Refractory Material Manufacturer

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