If spent acid can be recycled as dilute acid, is evaporation and concentration necessary for it to be valuable?
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If spent acid can be recycled as dilute acid, is evaporation and concentration necessary for it to be valuable? Is it not very useful when the concentration of the dilute acid added is low? Thank you!
It contains heavy metals; even if it’s concentrated, there’s no place to use it :(
Acid salt separation is carried out first, which is equivalent to purifying the acid; the resulting dilute acid is then quite clean. I wonder if this weak acid is useful or not? Is it necessary to concentrate it first before it can be used?
After the salt is separated, the heavy metals are removed and fluorine and chlorine are eliminated; this portion of dilute acid can then be added to the absorption system or further concentrated for reuse.
Could you please ask again? You mentioned that dilute acids can return to the absorption system; may I ask what are the typical requirements for the acid concentration in such a system? Can it be used without concentration? Thank you!
The amount of dilute acid that can be reused depends on the water balance issues in your dry absorption system; if a large amount of water is added during the dry absorption process, then the consumption of dilute acid can fully replace that amount of process water. You can also estimate the amount of water required for dry absorption by using data such as the inlet temperature of the drying tower, sulfur dioxide concentration, acid production concentration, and conversion rate; this will give you an idea of your consumption of dilute acid. There is a prerequisite: dilute acids need to have heavy metals, fluorine, chlorine, and other impurities removed through specific treatment processes before being added to the dry absorption process; otherwise, an excessive amount of such acids will affect the quality of the final acid product.
Based on the dry absorption balance, and taking into account the amount of dilute acid used, it is determined whether a concentration process is necessary.
I’ve learned something new; I need to study the dry absorption system as well. I’ll ask you for advice again if I have any questions!