Concentration of dilute hydrochloric acid
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There is currently 10% iron-containing waste hydrochloric acid, and I am looking for ways to concentrate this waste acid to around 25% so that it can be reused. What are the possible methods?
Distillation has been tried; it requires high energy consumption and yields little output. Hydrochloric acid forms an azeotrope at 20% concentration, preventing further evaporation of HCl gas
Could you please tell me exactly how to do it? Or what process can be used to achieve it?
A water-immiscible refrigerant is used to come into direct contact with hydrochloric acid; after heat exchange with the hydrochloric acid, the refrigerant vaporizes, and the water in the hydrochloric acid turns into ice
I’ve learned it, thanks for sharing{:1_90:}
Only about 21% hydrochloric acid can be obtained during distillation (at this point an azeotrope of HCl and H2O is formed); to increase the concentration, CaCl2 is added to break this azeotrope, and complete sets of technology are available in China for this purpose.
25% can only be achieved through vacuum distillation and additional absorption; conventional distillation is definitely not sufficient