Typical methods for the treatment of waste pickling solutions include precipitation by alkaline reagents, most commonly calcium hydroxide. As a result, large volumes of galvanic sludge form, containing iron, calcium, sulphates, and a relatively small quantity of zinc (<20%), making Zn recovery not profitable. In summary, state-of-the-art Zn galvanization processes entail the loss of valuable metals and the irrational and expensive handling of spent pickling solutions (SPSs). The resulting conclusion is that there is room for a significant improvement in the way SPSs are treated, with the double goal of enhancing Zn galvanization methods’ economic viability and achieving a lesser impact on the environment’s processes. The experimental results show that it is possible to use SPS as a coagulant to treat the process wastewaters, kept separated, and added with sodium hydroxide. The results in obtaining precipitates with Zn contents higher than 40%, increasing the added advantage of making Zn recovery profitable. The results show the possibility of using SPS as a coagulant in the process of physical-chemical wastewater treatment and sodium hydroxide to obtain a precipitate with a zinc content of more than 40%.
|Titolo:||Recovery of zinc from treatment of spent acid solutions from the pickling stage of galvanizing plants|
FERELLA, FRANCESCO (Corresponding)
|Data di pubblicazione:||2021|
|Appare nelle tipologie:||1.1 Articolo in rivista|
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|Recovery of zinc from Treatment of spent acid solutions _ Zueva et al..pdf||Articolo su rivista||Documento in Versione Editoriale||Open Access Visualizza/Apri|