The operating temperature of the sintering ignition furnace is 1200~1300℃, and the high temperature point can reach 1300~1500℃. Because the sintered iron ore powder, fuel, and flux in the ignition furnace will adhere to the furnace wall at a certain temperature and react with the refractory material castables in the furnace lining to cause chemical erosion. What kind of refractory castable material is suitable for lining the ignition furnace?
The lining of the ignition furnace generally uses composite furnace lining for internal structural treatment. First, use lightweight insulation castables for the insulation layer, and use anchor bricks to secure the insulation layer castables. The working layer, that is, the use area inside the furnace wall, uses high-aluminum and low-cement castables.
Due to chemical corrosion, the service life of the ignition furnace lining is greatly affected. There is serious slag hanging on the furnace roof and beams, and some refractory castables are falling off. There are also cracks in the burner area, resulting in a short furnace lining life, generally less than two years.
When selecting the ignition furnace lining, consider the working conditions of the lining.
The lining of the ignition furnace contacts the mixed raw materials in the furnace, and after a certain temperature, it will adhere to the wall of the ignition furnace to form hanging slag. The hanging slag is mainly AL2O3, Fe oxides and a small amount of CaO. The diffusion of iron oxide in the hanging slag erodes the matrix of the castables. It enters the interior of the refractory castable through the pores and cracks on the furnace lining, causing it to deteriorate and erode until it cracks and falls off.
Therefore, when selecting the lining of the ignition furnace, the working conditions of the lining of the ignition furnace must be considered. The refractory castable selected must be able to withstand temperatures of 1200 to 1400 ℃. Secondly, it has strong erosion resistance. More importantly, the refractory material castable must have strong erosion resistance. It has good resistance to slag erosion.
Select mullite composite refractory castable
Of course, the material fluidity of castables must be good, and ease of construction is the most important prerequisite. Low cement castable, small amount of cement added, low calcium content, good strength, but not very strong erosion resistance, mullite has low expansion, low thermal conductivity, excellent creep resistance, and chemical stability And corrosion resistance, are very suitable for use in the actual situation of ignition furnaces. Therefore, the use of composite type, mullite composite high-temperature resistant refractory castables is still very suitable for use on the lining of ignition furnaces.
Therefore, it is a good choice to use mullite composite refractory castables on furnace linings with strong slag resistance.
