Electrochemical Recovery of the Zinc Present in the Spent Pickling Baths Coming from the Hot Dip Galvanizing Industry by Means of the Use of Two Different Membranes

EXTENDED ABSTRACT Spent pickling baths coming from the hot dip galvanizing process represents an environmental problem due to high ZnCl2, FeCl2 and HCl (among other substances) concentrations. This problem, together with the decrease of natural reserves of nonferrous metals, makes zinc electrowinning coming from spent pickling solutions an interesting alternative. Moreover, membranes, or other kind of diaphragms, must be placed between the anode and cathode of the electrochemical reactor to minimize the presence of chlorine gas generated in the anode, which attacks the zinc deposits causing their dissolution. Therefore, the purpose of this work is to compare the behaviour of an Anionic Exchange Membrane (IONICS AR-204) and a Cationic one (NAFION 117).