Regarding the operation of \"post-alkaline washing\" in sulfur recovery units
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To meet stringent environmental regulations, many sulfur recovery units have an additional \"post-alkaline washing\" unit. May I ask: (1) What is the appropriate range for controlling the pH of the circulating slurry in the post-alkaline washing tower? (2) Is an oxidation tank to be installed? If set, what is the pH range for the wastewater from the oxidation tank?
1. The pH value of the circulating slurry should be maintained at least above 9. 2. An oxidation tank must be installed; a pH value of 8 is recommended
It can be adjusted based on the volume of gas and the concentration of sulfur dioxide; here we usually keep it around 7
The pH of the desulfurization solution should be above 7; there is no need to keep it too high； The pH at the outlet of the oxidation tank should be between 8 and 9.
Hello! Should the additional alkali washing be installed before or after the exhaust gas incinerator? Also, why is an oxidation tank needed? What is its function?