There are two kinds of corundum castables we often see, one is corundum refractory castables and the other is corundum mullite refractory castables. Both materials are commonly used in circulating fluidized bed boilers to do boiler lining refractory materials, both can be seen from the name contain corundum. As people in the industry know that both contain corundum, but the performance is completely different. Today, the refractory castables manufacturer will give you an introduction to the difference between corundum castables and corundum mullite castables.
Corundum castable is the use of corundum Al2O3 content greater than 90%, corundum-based crystalline phase of the refractory products and with the appropriate amount of dispersant, coagulant, stainless steel fiber, according to a strict formula composite and become. Corundum castables have many points such as good high-temperature strength, wear-resistant and anti-washout, high thermal conductivity, thermal shock resistance, corrosion resistance, good sealing, quick-setting and early strength.
Corundum castable is a refractory castable prepared with corundum as aggregate and powder plus some binding agent. It has higher mechanical strength and anti-abrasive properties than high-alumina refractory castables and mullite refractory castables, but the thermal shock resistance is a little worse. It is mainly used as the lining material of boiler, blast furnace, heating furnace, ceramic kiln and other kilns.
Corundum refractory castables formulated with corundum is a tripartite crystal system, the crystal type is generally short columnar, corundum itself also has a high thermal conductivity and electrical insulation properties, excellent chemical stability and resistance to the role of reducing agents. So corundum is unshaped refractory material in the refractory material raw materials, corundum is generally industrial alumina or bauxite by sintering or electro-melting made, so the industrial use of artificial corundum, but the density of artificial corundum and hardness are relatively large, so the use of the effect is also more significant.
Corundum mullite castables are made of dense corundum and mullite as aggregate, and white corundum powder, α-Al2O3 micropowder and mullite powder as fine powder. Corundum mullite castables have the common advantages of corundum castables and mullite castables; high-temperature strength, good resistance to thermal shock and good resistance to structural spalling; good resistance to thermal shock, high loading softening temperature, high-temperature creep rate is small, and good chemical corrosion resistance.
Corundum mullite refractory castable material preparation contained in the mullite is relatively small in nature, and industrial use of mullite raw materials are synthetic, with high purity, density is also relatively large, good organizational structure, low creep rate, low thermal expansion, good resistance to thermal shock and resistance to chemical corrosion of the advantages of strong. It is widely used in the refractory industry, and the development is also relatively rapid, but if the corundum and mullite than, corundum hardness and true density is much better than the mullite.
Adding corundum in refractory castables can make the aluminum content of the castables reach more than 90%, which improves the hardness and strength of the castables. However, by adding corundum and mullite to the castables, the aluminum content can reach 99%, and the hardness, strength and abrasion resistance can reach a certain range, and the application effect is also remarkable.
However, we need to note that when we use them, we often see corundum wear-resistant refractory castables and corundum mullite wear-resistant refractory castables. Even if you buy other types of castables, many manufacturers, for example, Fireramo, produce all wear-resistant refractory castables with more or less raw materials of corundum or mullite to improve the hardness of the castables and the effect of the construction. Therefore, adding corundum or mullite to the castables can play a stronger role and can further save customers’ money.
Simply put, corundum mullite refractory castables are actually a type of castable that performs better than corundum refractory castables. For what type of castables to be used for boilers, it is still necessary to determine the corresponding refractory materials according to the usage of the boiler.Fireramo, as a leading refractory manufacturer in China, we provide you with high-quality refractory castables, and we also support customized service. Tell us your application or requirement, you can get free samples!
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