What is the most reasonable drying heating curve of magnesia refractories? Products of less than 0.5T
You'd better oxidize magnesia preformed unit at room temperature for a longer period of time, then bake it, during which, it's enough to control the maximum temperature within 300 degrees. During the middle process, usually heating up for 4 hours and keep warm for 3 hours. The entire heating up process takes about 20 hours. If it is the site operation magnesia-based castable, it should be heated slowly in the early stage, and pay attention to keeping warm at 80 degrees Celsius. Every manufacturers has their own heating curves, so do not blindly adopt existing curves, try to make your own heating curve.
The material is very troublesome, it might crack horrendously if not baked well and all of them may be scraps after being took out from the furnace. Magnesia hydration is inevitable during the baking process. As volume expansibility of magnesite reaches 200%, so it is easy to crack. The key to bake is to quickly rule out the water vapor in furnace, especially within 150 degrees Celsius. After quickly ruling out the water vapor in furnace to avoid excessive reaction with magnesia of 150 degrees, it can be operated in accordance with convention. In addition, you should pay attention to the heat sources, for which i recommend electrical and coke to avoid generating a lot of water vapor during the natural gas combustion process which will worsen the situation.
