01. Different furnace lining atmospheres require different castables.
The lining atmosphere of the gasification furnace is different, and the castables used are also different. Zirconia series refractory castables are used for the oxidizing atmosphere, and silicon carbide series refractory castables are used for the reducing atmosphere.
02. Characteristics of silicon carbide series castables
Silicon carbide series castables have strong corrosion resistance and high wear resistance coefficient. Very effective in reducing melting loss. It also has the advantages of high thermal conductivity and good thermal shock resistance. It is most suitable for use in gasifier linings in reducing atmospheres.
03. Adding zirconia castables has stronger corrosion resistance
The temperature in the upper part of the gasifier is low, and high-strength gunning materials are used. Near the tuyere, the solid matter and ash remaining due to thermal decomposition are severely melted, and silicon carbide series refractory castables are also used on the side walls.
There is an oxidizing atmosphere in the furnace, which will produce slag and alkali corrosion. Generally, Al2O3-Cr2O3 series are used, and those containing chromium oxide are also used. This type has strong slag resistance and good corrosion resistance. But the porosity will be high. When the temperature in the furnace fluctuates, it will cause thermal spalling or be affected by slag infiltration, resulting in structural spalling and damage to the furnace lining. At the same time, because chromium oxide contains poisons, basically this material is not often used.
The use of castables added with zirconia will greatly improve the spalling resistance, and its corrosion resistance and slag resistance are both good.
04. What refractory castable is used for gasification furnace lining?
What kind of refractory castable is used for gasification furnace lining determines the service life and cost control. When selecting, the operating atmosphere of the furnace and the composition of the slag must be carefully studied and determined. To choose whether to use silicon carbide castables or zirconia series castables.
05.Conclusion
Because the furnace lining atmosphere is different, the same series cannot be used. After distinguishing the atmosphere, a suitable series of castables is selected for the lining, which virtually increases the use time of the furnace lining and saves production costs.
