Refractory materials for various kilns - 【 Refractory knowledge 】
Industrial kilns are mainly divided into glass kilns, cement kilns, coke ovens, and ceramic kilns. What are the refractory materials required for these kilns? Organized by Henan Chongde Refractory Editor
1、 Refractory materials used in glass kilns have chemical erosion, mechanical erosion, temperature fluctuations, and high-temperature effects. The selection of kiln materials mainly includes the following series:
1. Al2O3-SiO2 series; Mainly including clay bricks and silica bricks.
2. Al2O3-ZrO2-SiO2 series; Mainly including zircon bricks and fused zirconia corundum bricks.
3. ZrO2 SiO2 series;
4. MgO-Al2O3, MgO-Cr2O3, MgO-SiOz series;
5. Thermal insulation materials
2、 Refractory materials used in cement kilns mainly include the following categories:
1. Alkaline refractory materials; The main varieties include: magnesium chromium bricks, magnesium bricks, spinel bricks, dolomite bricks, etc. Magnesium chromium bricks can be divided into ordinary magnesium chromium bricks, directly bonded magnesium chromium bricks, and semi directly bonded magnesium chromium bricks.
2. Aluminum silicon refractory material; In addition to general clay bricks and high alumina bricks, they are mainly wear-resistant, alkali resistant, and temperature resistant. Special high alumina bricks have been developed, such as phosphate bonded high alumina bricks, wear-resistant bricks, anti peeling high alumina bricks, and alkali resistant semi acidic clay bricks.
3. Insulating refractory materials; Mainly including silicic acid cover plates and lightweight insulation bricks.
4. Castable materials: mainly include high-strength and high alkali castable materials, anti crust castable materials, low cement refractory castable materials, kiln mouth special castable materials, coal spray pipe castable materials, tertiary air duct special castable materials, and wear-resistant castable materials.
3、 Ceramic kiln castable: The inner wall material of the kiln wall requires high temperature resistance, and the type of refractory material selected is determined by the temperature at which the product is baked.
1. Use clay refractory bricks at temperatures below 1300 ℃;
2. Use high alumina bricks at 1300~1400 ℃;
3. Use silicon bricks at 1400~1500 ℃;
4. Use magnesium aluminum bricks at 1500~1600 ℃;
5. Use corundum bricks below 1800 ℃.
4、 Refractory materials for coke ovens
1. Refractory materials for carbonization rooms: Previously, clay bricks were mostly used, but now there is a trend towards using high-quality high alumina bricks, silica stone bricks, and red pillar stone bricks for masonry.
2. Refractory materials for combustion chamber: The combustion chamber and carbonization chamber share the same furnace wall, and the bricks used are the same as those for carbonization chamber.
3. Refractory materials for furnace top; Due to significant temperature fluctuations around the coal loading hole on the top of the furnace, clay bricks are used for masonry, while silicon bricks are used for other parts.
4. Refractory materials used in the ramp: The ramp connects the combustion chamber and the heat storage chamber, and requires a stable brick structure that can resist thermal stress. Small coke ovens are built with clay refractory bricks, while large and medium-sized coke ovens are built with silica bricks.
5. Refractory materials for the heat storage chamber: The single vertical wall, partition wall, bottom and grid brick masonry of the small coke oven heat storage chamber are all built with clay bricks, while the middle and upper masonry of the large and medium-sized coke oven heat storage chamber are all built with silicon bricks to ensure uniform expansion of the entire coke oven.
6. Refractory materials are used for small flue. The small flue is located at the bottom of the heat storage chamber and connected to the flue. The small flue is all lined with clay bricks.
The above is about the refractory materials used in industrial kilns. Masonry kilns are not only made of one type of refractory material, but also made up of multiple refractory materials.