Treatment of the filter cake after pressure filtration of magnesium oxide-magnesium sulfate wet desulfurization by-products?
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As the title suggests, the project was originally intended to recover magnesium sulfate; however, for certain reasons, the disposal method was chosen instead. In that case, should the filter cake obtained after filtration be treated as ordinary industrial solid waste? (I want to know exactly how to dispose of it and what the criteria are.) Also, the pH of the filtrate is within the acceptable range, but the pH of the filter cake is a bit high (the filter cake does not contain magnesium sulfite); I’m not sure if this is due to a high content of magnesium oxide If anyone with experience in this area is available, please feel free to offer some guidance; I would be extremely grateful!
The filter cake is evaluated according to the following standards, and its classification is determined based on the evaluation results: Technical Specifications for the Identification of Hazardous Wastes -- HJ/T 298–2007, and Standards for the Identification of Hazardous Wastes GB 5085.1–7–2007.
From which process stage does the flue gas entering the desulfurization system come? What preprocessing processes are there beforehand? A rough judgment can be made
The flue gas from the water-coal slurry boiler passes through an electrostatic precipitator before entering the desulfurization tower
The desulfurization tower uses light magnesium oxide as the absorption material; the by-products are oxidized within the tower and then discharged, while the filter cake is obtained through pressure filtration. (Using the magnesium oxide-magnesium sulfate method)
Isn’t calcium oxide generally used as a desulfurization agent in wet flue gas desulfurization?
Yes, but the calcium method tends to clog the pipes and nozzles
Oh, I’ve learned about it. But the method of feeding the material can be improved; I’ve seen it used quite often with the calcium method. I was wondering: in terms of raw material costs, how do the calcium method and the magnesium method compare?
The solution produced after oxidation is discharged directly, requiring forced oxidation. The filter residue is piled up or landfilled; it does not belong to hazardous waste, but is considered ordinary waste, just like gypsum
The materials produced by desulfurization are recycled by the company