High temperature corrosion of particulate matter during MSW combustion: Effects of particle size, inorganic minerals and additives on corrosion rates and mechanisms

The high temperature corrosion behavior and corrosion mitigation of PM with different sizes generated by MSW combustion were studied. The experiment result showed that the corrosion rate of 304 stainless steel increases significantly as the PM size decreases. The corrosive ability of PM1 on 304 stainless steel was about 3-5 times higher than that of PM10+ at 600 degrees C. Kaolin can greatly restrain the corrosiveness of PM. After 5% of kaolin was added, the corrosion rate of the PM generated by MSW combustion on 304 stainless steel was reduced by 12%. Calculating the composition of the particles after the formation of a stable slagging layer and ash deposition layer on the heating surface, the corrosion control efficiency improved to 71%. High-temperature corrosion process of PM was dominated by NaCl, KCl, CaCl2, Na2SO4 and K2SO4, the corrosion of alkali and alkaline earth chloride was generally stronger than that of sulfate at 600 degrees C. This study confirms that the addition of kaolin can effectively mitigate high-temperature corrosion in the superheater tubes of waste incineration furnaces.