The insulation effect of industrial kilns is one of the key factors affecting energy consumption. It is necessary to develop a product with a long service life and can reduce the weight of the furnace body. MG-28 is a mullite lightweight insulation brick with the characteristics of good high-temperature performance and low cost. Mullite lightweight insulation bricks are used for kiln linings, which can not only effectively reduce the weight of the furnace body and save gas, but also extend the service life of the furnace lining and reduce maintenance costs. Rongsheng Insulation Brick Manufacturer can provide high-quality insulation layer refractory products, including various refractory insulation bricks, boards, aluminum silicate fiber blankets, ceramic fiber blankets, etc.
Production of MG-28 Mullite Lightweight Insulation Bricks
Using industrial AL2O3 powder, clay, well-sintered bauxite and some kyanite as the main raw materials, wood chips (1mm screening) and polystyrene (diameter 2~0.5mm) are added to prepare lightweight bricks. Mix according to the predetermined chemical composition and ratio of the raw materials. First, add industrial AL2O3 powder, bauxite, kyanite and clay fine powder into the mixer and dry mix for 3~5min. Then add polystyrene balls, wood chips and binder (external), stir while adding, and roll out after mixing. The extrusion method is used for molding. After molding, the wet blank is dried at 50~60℃ for 48h and 100~110℃ for 72h and then fired. The firing temperature is controlled at 1400~1500℃ and kept warm for 8h. The appearance and physical and chemical indicators of the sample are tested according to relevant standards.
Index Characteristics of MG-28 Mullite Lightweight Insulation Bricks
The finished product of MG-28 mullite lightweight insulation bricks has a white appearance, clear edges and corners, and accurate size. Its physical and chemical indicators are: AL2O3 = 67.99%, Fe2O3 = 0.87%, volume density is 0.8g·cm, and compressive strength is 2.3MPa. The linear change after sintering at 1500℃ for 8h is -0.1%, and the thermal conductivity (800℃) is 0.24W·m-1·K-1.
According to the results of physical and chemical indicators, the AL2O3 content of the finished lightweight brick is 67.99%, indicating that this ratio generates more mullite. The Fe2O3 content is ＜1%, so the appearance of the brick after sintering is white (if the iron content is high, the brick will turn red after sintering). The compressive strength meets the standard requirements (≥2.1MPa) because industrial AL2O3 produces a volume shrinkage of about 13% during the firing process, which is conducive to the improvement of compressive strength. Clay and industrial AL2O3 have different degrees of volume shrinkage during the firing process. The mullite formation of alumina produces volume expansion, and the decomposition reaction of kyanite also produces volume expansion. The volume expansion and contraction of the system offset each other, so that the overall line of the product does not change much. At 1500℃, the line change after 8h firing is only -0.1%: the thermal conductivity (800℃) is 0.248W·m-1·K-1, mainly because the sawdust and polystyrene balls added in the test produce uniform small seven holes after firing, with uniform organizational structure and low thermal conductivity, achieving the energy-saving effect.
Application of MG-28 Mullite Lightweight Insulation Bricks
MG-28 mullite lightweight insulation bricks are used in the working lining of shuttle kilns in ceramic factories, with a normal operating temperature of about 1400℃. The high-temperature resistance, thermal conductivity, and heat storage performance are superior to those of the reference materials and have a long service life. It improves the quality and production capacity of the products and improves the working environment. After using JM28-0.8 mullite lightweight bricks as the working lining, the gas consumption of each kiln is about 160 kg. Compared with the original brick-concrete structure, each kiln can save about 40 kg of fuel, and the energy-saving advantage is obvious.
MG-28 mullite lightweight insulation bricks have the advantages of good volume stability, high compressive strength, and low thermal conductivity, achieving the purpose of saving gas and reducing the mass of the kiln.
Which one Has a Better Insulation Effect, Lightweight Insulation Brick or Refractory Fiberboard?
There are many types of lightweight insulation bricks and refractory fiberboards. The effect of use depends on the material used in the working layer to compare whether lightweight bricks or refractory fiberboards are better.
Lightweight bricks are divided into clay, high alumina, mullite, hollow alumina spheres, etc. Refractory fiberboards include PVC, asbestos, aluminum silicate, calcium silicate, ceramics, nano, etc. They are all selected for use according to different temperatures.
If the working layer uses refractory bricks, use the fiber series for insulation. If the working layer is refractory castables, use lightweight brick series as the insulation layer. Because if the working layer is refractory castables and fiber materials are used for insulation, the insulation effect will be discounted. Refractory castables have a water discharge process, and the discharged water is easy to penetrate into the fiber material, causing the insulation effect of the fiberboard to decrease.
If the working layer uses refractory bricks. Because refractory bricks are products that have been sintered at high temperatures, the insulation layer uses fiber materials without a drainage process. Therefore, the effect of using fiberboard is better than using lightweight bricks. Because the fiberboard is well integrated, it will not be crushed by refractory bricks and lose its insulation effect.
When using refractory bricks, it is also possible to use lightweight insulation bricks as the insulation layer. However, there is a defect that refractory bricks, because they are heavy materials, will crush lightweight insulation bricks. If crushed, lightweight insulation bricks will also reduce the insulation effect.
In short, it is impossible to say whether the use of lightweight insulation bricks and refractory fiberboards is good or bad, it can only be determined according to different usage conditions. If the materials of lightweight insulation bricks and fiberboards are similar, the insulation effect of fiberboards is better than that of lightweight bricks. However, different grades of insulation bricks will be used for insulation at different temperatures.
Therefore, it is difficult to say which of the two materials is better, and the effect can only be determined based on the working layer material or temperature.
Mullite Lightweight Insulation Brick Manufacturer
Rongsheng Mullite Lightweight Insulation Brick Manufacturer is a powerful manufacturer and seller of refractory bricks. Rongsheng is committed to providing high-quality refractory lining materials and insulation materials for high-temperature industrial furnaces, including various insulation bricks, insulation boards, ceramic fiber boards, ceramic fiber blankets, ceramic fiber modules, etc. Contact Rongsheng for free samples and quotes.
