With the continuous improvement and development of the glass furnace structure, the variety and demand of zirconia ramming materials are increasing. Domestic manufacturers of zirconia ramming materials have swarmed, forming a wave of production of zirconia unshaped refractories.
Zirconia Unshaped Refractories
Zirconia unshaped refractories can be divided into two categories: zirconia slurry and zirconia ramming material. Zirconia ramming materials are divided into two types: zirconite and zirconia alumina. The former is to add a certain proportion of crushed sintered zircon brick pieces to the zirconia mortar powder to form granular aggregates. The latter is added with granular aggregate after the fused corundum brick is broken. When using the above two ramming materials, add an appropriate amount of industrial phosphoric acid (H3PO4) with a concentration of 85%. After mixing, make the ramming materials wet and loose, and then ramming. After high-temperature sintering, it becomes a solid whole.
Rongsheng Zirconia Refractory Ramming Mass for Sale
Application of Zirconia Ramming Material in Glass Kiln
Among different zirconia ramming materials,
Some are zirconia ramming materials with aggregates. It is mainly used for the bottom ramming layer in the kiln for melting borosilicate glass.
Some are zirconia -alumina ramming materials. It is mainly used to melt the bottom ramming layer of soda-lime-silica glass, electric vacuum glass, and other alkaline glass furnaces.
Some belong to zirconia mortar. It is mainly used for mortar joints of zircon bricks or transition layers.
Some are intermediate repair materials. It is mainly used for repairing any refractory material that is not in contact with the molten glass in the flame space after corrosion.
There is also a mixture of ramming materials and intermediate repair materials.
Although the above-mentioned zirconia refractories have different uses, different chemical compositions, and various specifications, they are all called ramming mass refractory materials. Therefore, it often creates illusions for users. The manufacturer of Rongsheng refractory castables materials manufacturer reminds all customers that in the construction process, the wrong type should be avoided and the wrong place of the zirconia refractory ramming material should be avoided. So as not to cause the “ramming material” to peel off or be mixed in the glass liquid, causing stones and bubbles in the product. In severe cases, the glass furnace is damaged prematurely.
The Curing Mechanism of Zirconia Unshaped Refractories
Both zirconia ramming material and zirconia refractory mortar use phosphoric acid as a binding curing agent. Both types of powders contain AL2O3. When phosphoric acid (H3PO4) is added, H3PO4 reacts with AL2O3 to form AL(H2PO4)3 at 150°C. ALPO4 is formed at 236℃ and then combined with ZrO2 in zircon sand to generate Zr(H2PO4)4, Zr(HPO4)2, and Zr3(PO4)4. At 300℃~340℃, compounds such as ZrP2O7 are formed to cause bonding and solidify. When the temperature continues to rise to 1520~1550°C, decomposition occurs again to produce (ZrO) 2P2O7+P2O5. Among them, the phosphoric acid is completely volatilized at this temperature, so that the zirconia amorphous refractory material becomes a solid and integral hard block. Therefore, it is necessary to empty the furnace and heat the kiln to make the furnace bottom temperature exceed 1550°C.
Rongsheng Refractory Materials Manufacturer
Rongsheng is an experienced refractory manufacturer. Rongsheng’s refractory materials have been recognized by customers in more than 60 countries around the world. For example, Thailand, UAE, Turkey, Kuwait, South Africa, Malaysia, Vietnam, Netherlands, Philippines, Singapore, Egypt, Russia, etc. Rongsheng’s refractories have also served many glass furnace projects. Learn more about zirconia refractory bricks and zirconia unshaped refractory products for glass kilns. Please contact us. We will provide you with services according to your specific needs.
For some large rotary kilns, the heat load on the lower part of the Kiln Hoods is relatively high. If the general high alumina castable refractory is not well maintained and temperature rise controlled, they are prone to bursting and falling off. The top of the Kiln Hoods is close to the tertiary air duct, and the dust-laden airflow is relatively serious. Moreover, the construction of the top castable is relatively difficult, and the fluidity and early strength of the material are relatively high. Rongsheng refractory castable cement manufacturer recommends that the Refractory Material for Cement Rotary Kiln Hoods adopts high-strength wear-resistant castables with good high-temperature performance, strong thermal shock resistance, and wear resistance.
Why use the same refractory material for cement rotary Kiln Hoods and Coolers?
The Kiln Hoods is the kiln head part of the rotary kiln, and the cooler is supporting equipment for the rotary kiln. The top of the cooler has a high working temperature and large temperature changes. The low walls on both sides of the front end are long-term abraded by the high-temperature clinker coming down through the kiln mouth and also endured by certain mechanical and thermal stresses. The operating environment of these two parts is similar. Therefore, refractory manufacturers generally recommend the use of refractory materials of the same material. Rongsheng refractory manufacturers generally recommend the use of refractory castables in these two parts.
Why should refractory castables be used for kiln hoods and coolers?
According to the use conditions of the Kiln Hoods and coolers described above, the reasons for the use of refractory castables in the Kiln Hoods and coolers can be roughly summarized.
The refractory castable at the bottom of the kiln hood is subject to the rebound thermal shock of the high-temperature clinker coming down from the kiln mouth. For some large cement kilns, the daily output of the clinker is large, and the heat load on the premises is relatively high.
The top of the Kiln Hoods is close to the tertiary air duct, and the dust flow is relatively serious, and the castable has better wear resistance at high temperatures. Moreover, the construction of the top castable is more difficult, and the fluidity and early strength of the material are relatively high.
The bottom of the front end of the cooler is subject to the rebound thermal shock of the clinker, and the working temperature is relatively high and changes greatly. The low walls on both sides of the front end have been long-term abraded by the high-temperature clinker coming down through the kiln mouth and also endured certain mechanical and thermal stress damage.
<To sum up> According to the operating characteristics of the above parts of the cement rotary kiln, it is recommended to use high-strength wear-resistant castables with good high-temperature performance, strong thermal shock resistance, and wear resistance.
Rongsheng refractory material manufacturer provides special kiln hoods refractory castable products for cement kilns. Moreover, Rongsheng manufacturers can adjust the refractory formula of the kiln hoods according to the specific production needs of customers. Let every customer be able to do it in the production process, minimizing costs, and maximizing benefits.
Construction of refractory material for cement rotary Kiln Hoods
General refractory construction plan for Kiln Hoods
Exhaust holes should be left during the construction of the wall castables, and the holes should be drilled with a gas drill with a distance of 300*300mm. And it is embedded with Φ5mm wooden strips, the depth is half of the castable.
After the pouring hole of the Cement Rotary Kiln Hood is closed, 8 ventilation holes should be reserved and waterproof function should be ensured.
Construction scheme of kiln hoods ceiling
Use hanging anchors. Weld it on the L70*70 angle steel at a distance of 250mm*250mm. The angle steel is welded to the longitudinal I-beam of the original Kiln Hoods steel structure. The angles are arranged at a pitch of 250mm.
The mold is supported from below. Before supporting the mold, paste F10D aluminum silicate fiber cotton on the vertical surface of the surrounding old castable with high-temperature bonding powder (BP-1).
When pouring, pouring the castable in the order of ABCDEF. Then paste F10 aluminum silicate fiber cotton on the end surface with high-temperature bonding powder (BP-1).
During the pouring process, use the H100 calcium silicate board for laying. Or after pouring, use high-strength lightweight heat-insulating castable (HN-1.3 or Q1.3) for complete covering pouring (δ=1000mm).
After all, pouring is finished, use ordinary steel plate with δ=3mm to cover the surface (pay attention to the waterproof of the lap joint). And cut holes and weld steel pipes to leave several ventilation holes.
The technical scheme of brick masonry for kiln door cover vault
Brick supporting board at the bottom of the arch on both sides of S and N. When the brick supporting board at the bottom of the arch on both sides of S and N burns more than 1/2 the thickness of the brick, the brick supporting board should be replaced in time. Its specifications: 4150mm*330mm*10mm. If time permits, remove the old board before welding. If time is tight, weld directly on the original pallet. The fixed three sides are required to be fully welded and the working surface is flat.
Refractory brick masonry. The vault has a total of 17 rings of refractory bricks, which are built with the refractory mortar, and the mortar joint is controlled at 1mm. Before laying, the line must be laid out, three in the axial direction, three in the circumferential direction, and four in the circumferential direction. The masonry of refractory bricks must be based on this line.
Masonry of insulation bricks
Build a layer of 114mm thick insulation brick on the above refractory bricks, using insulation refractory mortar. There are 3 models (230*114*55/65mm or (60/65 or 65/65)) to match and concentrically build with refractory bricks.
The masonry of insulation bricks should be synchronized with refractory bricks. The upper gap is filled with aluminum silicate fiber cotton to facilitate the wedging of the rear refractory bricks.
RS Cement Rotary Kiln Burner Refractory Castable for Sale
Rongsheng is an advanced refractory castable manufacturer with a fully automatic and environmentally friendly refractory castable production line with an annual output of 80,000 tons. Has served customers in more than 60 countries and regions, for example, India, Pakistan, Kuwait, South Africa, Malaysia, Vietnam, Netherlands, Philippines, Singapore, Egypt, Russia, etc. Rongsheng has customized kiln hoods’ refractory castables, burner refractory castables, high-alumina high-strength refractory castables, and high-strength wear-resistant castables for cement rotary kilns. The product quality and customer service of Rongsheng’s unshaped refractories are leading in the industry. Get more product quotations on refractory material for cement rotary kiln hoods. Please leave your contact information and specific requirements on our website page. We will provide you with refractory materials that best suit your production needs according to your actual working conditions. Save production costs and improve economic efficiency.
Low cement castable refers to a castable with low cement content. The cement dosage of refractory cement castables is generally 15% to 20%, and the cement dosage of low cement castables is about 5%, and some even reduce to 1% to 2%. Application of Low Cement Castable. The purpose of reducing the amount of cement is to improve the fire resistance of the castable. After molding and curing, less cement hydrate is formed. During heating and baking, there is no problem that a large number of hydration bonds are destroyed and the medium temperature strength is reduced. Instead, as the heat treatment temperature increases, it gradually sinters and the strength gradually increases. The water requirement of the castable is greatly reduced, so the porosity is low and the volume density is high. From the refractory castables manufacturer, it is very suitable for all kinds of heating furnaces and soaking furnace refractory lining materials.
Construction of Low Cement Castable on Soaking Furnace
Low cement castables and ordinary castables are both refractory castables combined with calcium hard aluminate cement, which are widely used in thermal equipment in metallurgy, petroleum, chemical, and other industries, and have achieved good results. In the overall pouring of the soaking furnace, the installation of anchoring bricks, the retention of expansion joints, and the 20 Pa pressure operation of baking below 200 ℃ for 4 days are the key points.
When low-cement castable is cast as a whole, it is poured layer by layer from the bottom of the furnace wall up. Take the height of two anchor bricks as one layer, paste ceramic fiber felt, build light clay bricks, and support the template. The mixed low cement castable can be poured into the formwork through the funnel. Flatten and shake with a vibrating rod, which is very important. Whenever it is poured to the horizontal position of the anchor brick, it is best to be 20 mm higher than it. Then the anchor bricks are kneaded, squeezed, and hung by hand so that they are stably placed on the required horizontal position. When pouring to the furnace mouth, spread two layers of oil felt paper to ensure easy removal during intermediate repairs. It can be demoulded 2 days after pouring.
Low cement castables rely on the addition of several special raw materials to obtain good performance. In the Application of Low Cement Castable, First, pure calcium aluminate cement, due to the high content of effective mineral CaO·Al2O3, can obtain the required strength with less mixing. The second silica fume is glass beads with a SiO2 content between 93% and 98% and an average particle size of about 0.5 μm. After adding silica fume, the castable has good fluidity, low molding water requirement, and low sintering temperature, which improves the performance after heat treatment. Third, alumina powder is easier to participate in the reaction and improve the fire resistance of the material. Fourth, the water reducing agent, which can be adsorbed on the surface of the powder, and then generate electrostatic repulsion to disperse the powder, so as to further play the role of fine powder.
Oven-drying after Casting Low Cement Castable
The oven-drying is an important part that directly affects the service life of the soaking pit of the low cement castable. During the Application of Low Cement Castable, they contain ultrafine oxide powders, so they have the weaknesses of poor air permeability and poor chipping resistance. Cracking is a phenomenon produced when the internal steam pressure of the castable increases beyond its strength during the drying period. It is closely related to the diffusion rate of steam, that is, the air permeability of the pouring body. For this reason, the oven-drying curve should be controlled within 200°C in the first 4 days, and the temperature should be lower at the beginning, and the oven-drying should be operated with slight positive pressure. The practice has proved that this method effectively overcomes the cracking and lays an extremely favorable foundation for the subsequent heating of the oven-drying.
Rongsheng Low Cement Wear Resistant Castable for Sale
Since the first furnace pit was poured, more than 2,400 tons of low cement castables have been successfully used. From construction, oven-drying to formal production, low-cement castables have the characteristics of good pressure resistance, high flexural strength, good high-temperature volume stability, and good thermal shock stability at low, medium, and high temperatures. The average life of each furnace pit is more than 3 years. Practice shows that low cement castables are good materials for soaking furnace pits. For more information, please contact rs low cement castable manufacturers.
Lightweight insulation castables are composed of high-quality, high-strength raw materials, aggregates and ultra-fine powders, and compound additives. Because the light-weight insulation castable is a powdery and granular refractory material made of certain refractory materials such as alumina and some binders. It has high fluidity and is mainly formed by pouring in construction. Lightweight insulating castables have the advantages of high strength, small volume density, low thermal conductivity, good insulation performance, and convenient construction. It is an ideal choice for industrial boiler insulation materials.
Lightweight Insulation Refractory Castable
RS Lightweight Insulating Castable for Sale
Construction method: vibration or manual ramming construction.
Main function: Insulation and heat insulation to reduce the external temperature of the furnace wall.
Q:How to mix light-weight insulation castable?
A:The mixing of castables requires the use of forced mixers and special mixers.
The light-weight castable insulation is made of aluminate cement, high-alumina fine material, ceramsite, plus several additives. It has the advantages of high refractoriness, high strength, and low thermal conductivity. The heat preservation casting material of the invention has the characteristics of low thermal conductivity and small volume density, which can reduce the heat and heat energy consumption of industrial kilns and reduce the weight of the furnace lining. In the high-temperature light-weight insulating castable, the raw material of the high-temperature light-weight castable that can be used above 1200°C is a porous material. Mullite, corundum, high aluminum, siliceous and magnesia and other porous clinker or light refractory brick. This castable can be directly used in the lining of 1350℃ atmosphere furnace.
Lightweight thermal insulation castable has the following advantages:
The high-temperature resistance and high strength.
Low thermal conductivity.
The small volume density, reduce kiln heat consumption.
Convenient construction and reduce labor intensity.
Light texture, reduce the weight of kiln lining.
resistant to acid and acid gas corrosion.
Characteristics of heat insulation, heat preservation, and low water absorption.
In addition, the lightweight insulating refractory castable is not only easy to construct but also the most ideal product for construction with alkali-resistant parts at high temperatures. Moreover, the workability is good, the bonding force is strong, and the initial setting time and the construction operable time are long. The strength increases quickly, the impermeability is strong, no acidification treatment is needed, and it is easy to ensure the denseness and fullness of the masonry gray joints. Can significantly improve the airtightness, integrity, and anti-corrosion ability of the chimney lining wall. It is an ideal cementing material for a high chimney, high-temperature flue, and air duct lining.
The Use of Light-weight Insulation Castable
It is suitable for unshaped refractory materials formed by pouring. It is easy to ensure the denseness and fullness of the masonry gray joints, which can significantly improve the airtightness, integrity, and corrosion resistance of the chimney lining wall. It is suitable for a high chimney, high-temperature flue, and air duct lining. Lightweight insulating castables are mainly used for lining thermal insulation devices such as high-temperature industrial kiln insulation. It can also be used in acid-resistant projects such as acid-resistant tanks and tanks in petroleum, chemical, nonferrous metallurgy, and other industries.
Rongsheng refractory castable manufacturer has an annual output of 80,000 tons’ production workshop. As a manufacturer of high-quality refractory castables, the light-weight heat-insulating castables produced have the advantages of moderate strength and good insulation performance. Lightweight insulating castable is made of aluminate cement, high-alumina fine material, ceramsite, and some additives. Lightweight insulating castables have the characteristics of lightweight, high compressive strength, acid and acid gas corrosion resistance, heat insulation, heat preservation, and low count rate. In addition, Rongsheng’s acid-resistant bricks, acid-resistant clay and wipe fabrics, acid-resistant bricks, acid-resistant clay, and wipe fabrics are self-developed refractory materials suitable for thermal insulation of power plant boiler chimneys and heating network pipes. They have the characteristics of acid corrosion resistance, temperature resistance, heat resistance stability, and convenient construction.
Get the refractory castable service from Rongsheng, please leave your specific needs in the message box on our page, we will reply to you in the shortest time.
Lightweight castable is mainly made of aluminate cement, high alumina fine material, ceramsite and other additives. Lightweight refractory castable sales with light volume, high compressive strength, acid and acid gas corrosion resistance, heat insulation, heat preservation, low water absorption characteristics.
The series of refractory insulation castable is composed of lightweight refractory aggregate and powder, and the binder admixture is called lightweight castable. Lightweight refractory castable sales are mainly used in high chimney, high temperature flue and air duct lining, petroleum, chemical, nonferrous metallurgy and other industries acid tank, tank and other acid resistant engineering.
The type and amount of cement, refractory powder and light aggregate used in lightweight castable refractory are not the same, so are their functions. The reduction of water consumption and the improvement of strength with the addition of water-reducing agent are remarkable. The addition with small bulk density can reduce the volume density of castable and improve its heat insulation function, but the strength is reduced twice, and the more the dosage is, the more significant it is. Therefore, according to the working conditions of the furnace and the position of castable, the reasonable selection of lightweight refractory castable can achieve the intention of energy saving.
The manufacturing and molding of lightweight refractory castables are essentially the same as refractory castables. The difference is that the bulk weight of light aggregate is small, easy to absorb water, so the weight of light aggregate should be weighed, poured into the forced mixer, first add half of the water, wet mixed evenly, then add refractory powder and cement, and add the rest of the water mixing. When forming, aggregate is easy to float up, forming layers, so the vibration time to be shorter, should be controlled. Lightweight refractory castable sales shall be maintained in a wet environment after initial setting in accordance with a professional process. 1 day after the removal of mold, Portland cement and CA-50 cement lightweight refractory castable samples, should be maintained for 6 days and 2 days. Then, check its functionality. The drying compressive strength is greater than 6Mpa. With the increase of heating temperature, the strength decreases. When it reaches 1300℃, the strength increases, which is caused by the sintering of powder.
This series of refractory castable is easy to construct and is the most ideal product for alkali resistant parts at high temperature. Mainly according to the porosity, binder, aggregate classification. In practice, it is often classified by the use of temperature or functional characteristics. According to the porosity, there are two kinds of dense castable material and insulation burning material with the porosity not less than 45%. According to the binder there are hydraulic binding, chemical binding, coagulated binding castable. There are clay aggregate, high alumina aggregate, silicon aggregate, alkaline aggregate, special aggregate and insulation aggregate.
Zhengzhou Rongsheng Kiln Refractory Co.,Ltd. is professional refractory castable manufacturer. Over the years, we are committed to the production of high-quality refractory materials, and more than 60 countries and regions reached friendly relations of cooperation with customers. Refractory products stable quality, complete varieties, worthy of customer trust, welcome to purchase, we will serve you wholeheartedly.
Low cement castable refers to the new castable with very little fusion usage. What matters is the choice of extremely fine particles no more than 1 m. Its high-temperature shock resistance, slag resistance, corrosion resistance ability significantly improved, beyond similar insulation bricks. Ultra low cement refractory castable and non-cement castable can be obtained by further reducing the content of fusion agent.
This series of refractory castableis mainly made of fire-resistant stone, granular material as fire-resistant raw material, with fusion agent and preservative added, and then made of mixed rubber. Low cement refractory castable is generally used as the fusion agent for aluminate cement, the amount of cement added can harm the overall process performance of the castable, high temperature compressive strength, corrosion resistance, and so on. Refractory castable with aluminate cement as the fusion agent can be called low cement castable if CaO content is less than 2.5%. Castable with CaO content between 1.0 and 2.5% May be called ultra-low cement castable. Low cement castable is a high-end refractory castable, low content of CaO in cement, so called low cement castable.
Low cement refractory castable is mainly used for lining of heat treatment furnace, various heating furnace, heating furnace cover, shaft kiln, machinery, iron blast furnace outlet, ladle, molten iron ladle, etc. Gravity type low cement castable for metallic materials of high temperature fire prevention of the exterior wall rock wool board lining of prefabricated body, such as heat treatment furnace water-cooled heat outside the pipe line, spewing metallurgical industry with overall body spray gun line, RH, DH vacuum degassing device of presoak pipe lining, ladle and petrochemical gas path components of tubular reactor for catalytic cracking equipment lining of high temperature wear resistance of the body; It can be used for structural analysis of the location of the project construction, can further improve the overall application of practical results.
Before the choose and buy, remind everybody to want to confirm first is the low cement castable of what material, common have clay qualitative, tall aluminous qualitative, mullite qualitative, aluminous magnesia qualitative, just jade qualitative, below the condition that material is different, the price of low cement castable also is completely different. Then the same refractory material of low cement castable, according to its main technical indicators and a key index for Al2O3 content, the higher the content of characteristic is, the more good, the match with extremely high content of calcium oxide content is, the more low, the higher the pressure test the compressive strength, the higher the compressive strength, compressive strength and line after burning rate is lower. The refractoriness of clay and high aluminum is above 1790℃ except that of clay and high aluminum.
When selecting refractory materials, the technical performance requirements of refractory materials must be put forward according to the specific conditions of the furnace. The Rongsheng refractory castable manufacturer believes that the technical performance of the refractory used in the bloom heating furnace should be considered. Such as high softness, resistance to rapid cold and heat, small linear change, high strength at room temperature, medium-temperature, and high temperature, and slag resistance in several aspects. Therefore, high-strength and high-alumina mullite castables are the best choices. In this castable, part of mullite and additives are added. In order to promote the formation of a large number of mullite as much as possible, and to ensure high strength at room temperature, medium-temperature and high temperature, and good construction performance. The properties of high-strength and high-alumina mullite castables are shown in Table 1.
Performance of High-Strength and High-Alumina Mullite Castable
Table 1 Performance of High-strength and High-alumina Mullite Castable
Al2O3 (w/%)
70
Drying at 110℃, Bulk Density (g/cm3)
2.5
1350℃ × 3h, Linear Change Rate
-0.2 ~ +0.3%
Flexural Strength (MPa)
110℃ × 24h
4
1350℃ × 3h
10
Compressive Strength (MPa)
110℃ × 24h
22
1350℃ × 3h
90
Max Use Temperature (℃)
1600
Refractoriness (℃)
1790
Requirements for On-site Construction of High-Strength and High-Alumina Mullite Castables
In order to obtain the expected effect of mullite castable, in addition to reasonable design and good quality of the castable itself, the construction quality is also an important factor.
(1) Preparation before construction
High-strength and high-alumina mullite castables are formulated with multiple components. Active composite ultrafine powder and a small amount of pure calcium aluminate cement are added, which is more active. Therefore, the storage conditions and time requirements are relatively high, and it must be strictly protected from moisture. If the packaging is damaged or affected by moisture, it is not allowed to use. Its storage period should not exceed two months from leaving the factory. Construction machinery must be cleaned up to ensure the normal operation of construction machinery, such as forced mixers, vibrating rods, scales, and drill drills.
(2) Installation of anchor bricks
The arrangement of anchor bricks in the refractory castable lining must be horizontal and vertical. The proper distance is 400～500mm. The anchor bricks should be fixed during construction, and they should not be displaced due to construction forces. In order to prevent displacement, wooden wedges can be used for positioning.
(3) Setting of expansion joints
Expansion joints are determined according to the linear rate of change of mullite castable and experience. The high-strength and high-alumina mullite castable is reserved for 4 to 5 mm per meter of cast body. After pouring, the outside of the expansion joint should be covered and sealed with clay bricks. After putting into production, there should be no fire, and the plugging material should be easy to melt.
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Before construction, the operator should be able to grasp the operating points and quality requirements of each process. After the ingredients are added to the mixer, dry mix and mix for 1 minute, and then add water. If the material is too dry or too thin, it will affect the quality. Generally, it can be kneaded into a dough and made into a slurry by hand. It is strictly forbidden to add water temporarily when pouring out of the tank. Once the amount of water added is determined, it should not be changed easily to ensure the consistency of each mixing.
Generally, the stirring time is 5 minutes, too long or too short is not good. The mixed castable should be poured immediately, and parked in the middle should not exceed 20 minutes. The pouring material should be laid evenly at the construction site, and the formwork, expansion board, anchor brick, and other facilities should not be touched and dislocated due to excessive force.
Generally, the vibrating rod is used to vibrate the material about 300mm, and each part should be re-slurried. When pulling out the vibrator, you should lift it slowly to avoid leaving holes. If you find that there is no vibration, dig out and re-tighten it. After pouring, the surface of the pouring body does not need to be polished.
Normally, it is naturally maintained for 2 to 3 days, and it is strictly forbidden to step on or touch it during the maintenance period. When the castable is solidified, vent holes should be pierced in time to help eliminate water vapor. The mold can be demolded after confirming that it has sufficient strength.
Oven-drying after On-site construction of high-strength and high-alumina mullite castable
The quality of the lining on-site pouring is of course very important, but the baking quality of the lining is directly related to the success or failure of the castable application. The pouring body contains a large amount of free water and crystal water, which need to be fully removed by the oven-drying, which is an extremely important link for the longevity of the furnace lining. As the volume and pressure increase sharply when the moisture becomes water vapor, if the baking temperature rises too fast, it will cause the furnace lining to crack, peel off or explode.
High-strength and high-alumina mullite castables are dense and high-strength types, with low porosity, and it is not easy to remove moisture. Especially in the removal stage of a large amount of free water in the temperature range of 100-300 ℃, it is easy to cause excessive steam pressure and cause the furnace lining to peel off or explode. Therefore, special attention should be paid, and sufficient time should be given for elimination. As the temperature continues to rise, free water and crystal water are continuously removed. When it reaches 500 ℃, the moisture content of the castable only accounts for about 10% of the total water content.
Therefore, the temperature of the castable should be slow before 600℃, and there should be enough holding time. After 1000 ℃, mullite began to form in large quantities. After the formation of the primary crystals of mullite is basically completed at 1300 ℃, the mullite grains continue to grow so that the castable is densified, the bonding force increases, and the strength increases. On the basis of summing up the experience of the last few oven-drying, we assigned four working teams to oven-drying. Record the temperature changes and fuel consumption of the heating section, soaking section, and preheating section every hour. Finally, through everyone’s joint efforts, the oven-drying task was completed satisfactorily. It can be seen that the oven-drying after the on-site construction of high-strength and high-alumina mullite castables is a very important step, and it is also a step that requires more attention and careful operation!
Rongsheng refractory material manufacturer is an experienced manufacturer of refractory castables. Rongsheng’s refractory products have been sold to more than 60 countries around the world. Rongsheng’s advanced monolithic refractory castable production line has an annual output of 80,000 tons. We not only have strong strength in the production of refractory castables but also have rich experience in providing customers with solutions for uncertain refractory linings. If you want to buy high-strength and high-alumina mullite castables, Corundum mullite castable, mullite insulating castable, etc., or want to get more information about Rongsheng refractory manufacturers, and learn more about the prices of monolithic refractory products, please contact us. We will provide you with services according to your specific needs.
Aluminum cement is a hydraulic cementation material made of high alumina or industrial alumina and calcium carbonate (limestone) in a certain proportion, calcined or electrofused clinker made of calcium aluminate as the main component, alumina content more than 50%, and then ground. The series of refractory cement is usually yellow or brown, but also gray. The main mineral components of alumina cement manufacturing are monocalcium aluminate and other aluminate, and a small amount of dicalcium silicate, etc. It has a high refractory temperature and stability, and is often used as a binder for unshaped refractory materials.
2. Alumina cement manufacturing has high heat resistance, and refractory thick and fine aggregate (such as chromite, etc.) can be made into high temperature resistant (1300 ~ 1400℃) heat resistant concrete;
3. It is used for construction emergency works. Aluminate cement is fast in setting and hardening, and its 1D strength can reach more than 80% of its strength. It is mainly used for emergency projects within construction period, such as national defense, roads, special emergency repair works (leak plugging) and temporary works.
4. High alumina cement is mainly used in sulphate corrosion resistant engineering. It has strong resistance to sulfate corrosion under ordinary hardening conditions, because the cement stone does not contain tricalcium aluminate and calcium hydroxide, and the density is large.
5. This series of refractory cement can also be used in winter construction. Aluminate cement has high hydration heat and concentrated heat release. The heat of hydration released within 1d is 70% ~ 80% of the total amount, which makes the internal temperature of concrete rise higher. Even under -10℃ construction, aluminate cement can set and harden quickly, which can be used for winter construction.
Alumina Cement Advantage
1. It has stable performance, high strength, fast generating strength and strong applicability.
2. Can also be used to prepare refractory castable, prepared low cement refractory castable, light refractory castable, refractory spray coating and other indeterminate refractory materials.
3. High alumina refractory cement can be used to produce precast refractory blocks, slag balls and other shaped refractory materials.
4. Prepare temporary fast construction, rush repair, support concrete, prepare sulfate resistant mortar and other building materials.
Alumina cement manufacturing can be combined with refractory aggregate, powder and some additives into refractory castable, with higher liquidity, high-temperature resistance, wear resistance, such as high aluminum castable, steel fiber castable, corundum wear castable. We are not only the manufacturer but also to provide customers with quality after-sales services, timely delivery of goods, timely delivery, customer satisfaction and then sign for customers to save time and cost.
Our common unshaped refractory can be divided into castable material, plastic, ramming material, spraying material, projective material and coating according to the construction method and material properties. Unshaped refractory supply with a certain size of refractory aggregate and powder, binder, admixture of refractories, also known as bulk refractories. Used for lining of thermal equipment, direct baking without sintering process.
Refractory castable is a kind of granular and powdery material made of refractory material, which is composed of a certain amount of binder and water. It is a common amorphous refractory with high fluidity, suitable for casting and hardening without heating. It consists of refractory aggregate, powder, binder, admixture, water or other liquid materials. Generally in the use of the site by casting, vibration or tamping method casting molding, can also be made into prefabricated used.
Refractory castable is one of the most widely used amorphous refractory materials. Mainly used to build a variety of furnace lining and other integral structures. Some high quality varieties can also be used in smelting furnaces. Unshaped refractory supply for example, aluminate cement refractory castable can be widely used in various heating furnaces and other thermal equipment without slag and acid and alkali erosion. In the hot metal, molten steel and slag erosion and the working temperature is higher, such as out of the steel trough, steel barrel and blast furnace body, out of the iron groove, etc., can be used by low calcium and pure high alumina cement combined with higher alumina and sintered good quality granular and powder material made of refractory castable.
Again if phosphate refractory castable can be widely used in heating furnace and heating metal in soaking pit, also can be used in coke oven, cement kiln directly with the parts of the material in contact. The use of high quality phosphate refractory castables to repair parts of metallurgical furnaces and other vessels in direct contact with slag and molten metal also has good results.
As the ratio of unshaped refractory supply in refractory, refractory castable is bound to develop rapidly, at the same time varieties increase quality will also increase, the key still will develop low cement, ultra-low cement and without cement refractory castable, combining resource conditions homogenization and high-quality raw materials to improve the basic and special aggregate composition, research and promotion of using fiber reinforced refractory castable and their refractory castable, apply various additive to improve the performance of refractory castable.
As monolithic refractories are rising year by year, proportion of refractory and amorphous refractory has to save energy, simple production process, convenient construction, long service life, the integrity of the furnace lining is good wait for a series of advantages, its application range is given priority to with warm parts of the evolution in the field of high temperature, and many are used under the condition of complex and serious.
Clay castable refers to castable with a content of AL2O3 greater than 38%, and high aluminum castable refers to high aluminum aggregate with a content of AL2O3 greater than 50% as granular raw material. It has high fluidity, suitable for construction by pouring method, and can harden without heating. Clay refractory castable consists of refractory aggregate, powder, binder, admixture, water or other liquid materials. Generally in the use of the site by casting, vibration or tamping method casting molding, can also be made into prefabricated used.
This series of refractory castable is made of clay clinker and fine powder as raw material, mixed with micro powder additive and cement as binder, which is used to fill the gap between steel brick of furnace throat and shell and the secondary casting layer of the lower part of water-cooled tube of furnace bottom. It is used in the bottom screed of water cooling pipe or the inner gap of steel brick of furnace throat and the gap between steel brick and furnace shell, and also used in hot air furnace system.
Clay refractory castable series for aggregate with bauxite and flint clay, silica powder, calcium aluminate cement, water reducing agent prepared general castable, choose corresponding grade aggregate, mixture volume density of 2.2 clay castable for customers to use. The refractory product compact structure, high temperature performance is good, good thermal shock resistance and abrasion resistance, construction is convenient, suitable for all kinds of neutral industrial kiln lining.
The clay castable is widely used in a variety of industrial furnaces, the general use temperature of about 1000-1200℃. The aluminum content of clay castable is about 45%. The compressive strength is about 30Mpa. If the thermal shock requirements are high, we must use tertiary clinker for aggregate production, now, there are a lot of waste tertiary brick clay aggregate, aluminum content and refractoriness are no problem, but the thermal shock will be less.
So, buy clay refractory castable cannot listen to price only, price decides quality, not empty at all, take 3 class waste brick and 3 class clinker make castable, the price is about to differ several hundred, and a few customers, listen to price, think that low that clinch a deal, actually this has a lot of quality discretion problem inside. The bulk density of clay castable is different from that of clay-based tight castable. Generally, the bulk density of clay castable is 2.1g/cm3, while that of tight clay-based castable is 2.3g/cm3. This is because the material with other substrates is added in the process of tight clay- based castable, which is more resistant to slag and erosion.
The quality of clay castable varies greatly, so the use of furnace temperature and erosion must be seen when selecting. We are professional refractory material manufacturer, we are committed to the production of high quality refractory products, and many customers to achieve friendly relations of cooperation, welcome to consult the procurement.
