Sillimanite bricks are divided into 65 and 60 sillimanite bricks according to the technical data. Hongtai Refractories has been specialized in the production and research and development of refractory bricks for many years. The company persists in seeking development with quality, continuously improving the technical content and technical strength of products, continuously releasing new products, and pursuing consumers with suitable prices and high-quality products. Provide satisfactory and efficient service!
The company produces mullite bricks, sillimanite bricks, and andalusite floor tiles for a long time. The aluminum content is more than 65%, the iron content is less than 1%, the apparent porosity is less than 20%, the volumetric relative density is more than 2.5, and it is resistant at room temperature. The compressive strength of the compressive test exceeds 80, and the softening temperature under load exceeds 1600. Warmly welcome information and purchase!
Sillimanite bricks are thermal insulation bricks made of sillimanite minerals. Sillimanite is converted into mullite and free silica after being calcined at high temperature. It is usually manufactured by high-temperature firing method and drilling mud pouring method. The physical and chemical properties of high-alumina refractory bricks are improved, with a refractoriness of 1770～1830℃, and the starting point of softening under load is 1500～1650℃. It is mainly used for the formation of the liquid hole of the laminated glass tank kiln, the charge of the iron-making blast furnace, the throat and the ceramic craft kiln furniture.
Sillimanite is this kind of high-quality fireproof raw material. It is used to produce high-alumina refractory bricks with low stress relaxation, high-load softness and slightly swelling high-fired shock bricks and heating furnace roofs. The concrete rotating cellar is made of polyphosphate and high-alumina. Refractory bricks, etc.
Characteristics of sillimanite brick
1. Mixing sillimanite into the material of thermal insulation bricks is beneficial to the improvement of the properties of thermal insulation bricks. With the improvement of sillimanite, the actual effect is more obvious.
2. The content of Al2O3 in sillimanite is high, and the heat-preserving bricks are closed without firing. If the content of Al2O3 is low, the heat-preserving bricks are fired and closed.
3. The addition of sillimanite has no harm to the porosity and volume relative density of the thermal insulation brick. The high content of Al2O3 in sillimanite will result in a higher load softening temperature for the made insulation brick, but the compressive strength of the insulation brick is slightly lower.
Features: Thermal insulation brick made of sillimanite minerals. Sillimanite is converted into mullite and free silica after being calcined at high temperature. It is usually manufactured by high-temperature firing method and drilling mud pouring method.
Main application: Mainly used for forming the flow hole of the laminated glass tank kiln, ironmaking blast furnace charge, furnace throat and ceramic craft kiln furniture. Sillimanite crafts include sillimanite bricks, material bowls, material bowls, material rods, punching needles, material channels and so on.
What is the difference between sillimanite brick and high alumina refractory brick
Generally, high-alumina refractory bricks usually refer to an Al2O3 content of 48%~65%; its refractoriness is ≥1790℃, and its softening temperature under load is 1420~1500℃; The load becomes soft and the temperature is high.) Its relative density is 2.40 to 2.65g/cm3; its key defect is its high stress relaxation rate and poor thermal shock resistance compared to clay bricks.
The melting temperature of andalusite is different from that of sillimanite. At the calcining temperature of about 1400℃, the sillimanite crystal in the handicraft is not converted, and the andalusite crystal is not completely converted. Therefore, in the whole process of application, this kind of crystallization is again lost. With the increase in microanalysis of petrochemicals, it is able to offset the shrinking caused by the increase in the amount of high-efficiency liquid phase of the crafts at high temperatures, and increase the load of the crafts to soften the temperature. In addition, high pressure forming has the effect of reducing porosity and improving compressive strength.
If the necessary proportion of sillimanite and other nutrients are added to the seasoning of high-alumina refractory bricks, it will become sillimanite bricks, which will improve the thermal shock resistance of the crafts. The refractoriness of sillimanite brick is 1770-1830℃, and the temperature at the beginning of softening under load is 1500-1600℃.
High-alumina refractory bricks are mainly used for the central and southern barrier walls of the heat storage chamber, and sillimanite bricks are mainly used for the grate of the heat storage chamber.
According to the regulations on sillimanite bricks (H31) where sillimanite bricks (H31) are applied, the following problems need to be grasped when developing and manufacturing sillimanite bricks (H31) for ironmaking blast furnaces:
(1) Selection of raw materials. The raw material adopts Al2O3-SiO2-ZrO2 series aluminum-rich zone, where refractory and mullite are the key series. The two end-member raw materials often have the characteristics of high-temperature structure with high compressive strength or thermal shock resistance and corrosion resistance. If ZrO2 multi-component is added, the resistance to adhesion is more beneficial.
(2) Microstructure manipulation. Scientific research and production of refractory insulation materials, the microstructure is the key problem. According to the manipulation of the microstructure, improve and enhance the characteristics of the product. The key to H31 sillimanite bricks is to manipulate the phases: 1) reduce the amount of laminated glass and improve the adhesion resistance of the crafts; 2) increase the content of the crystalline phase to make the crafts as fully crystalline as possible. The crystalline phase uses mullite-refractory polymer material dominated by mullite, and the other also has an oblique zircon (ZrO2) phase.
(3) Choose effective particle grading, high pressure forming and pressure shock forming to reduce porosity and improve compressive strength.
According to the H31 model of sillimanite brick research and development and manufacturing concepts, mullite-refractory is selected as the stone, sillimanite is the key cultivation substrate, similar to the production process of high alumina refractory bricks, and calcined at a temperature of less than 1550℃ , Can produce sillimanite crafts for iron-making blast furnace.
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