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-Zinc electrowinning is performed with the application of a current through insoluble electrodes (Pb-Ag), causing the electrolysis of zinc sulfate, with or without impurities, and zinc deposition on the cathode of aluminum. The impurities can reduce the current efficiency and increase the energy consumption in zinc electrolysis. In this work, the effect of nickel and magnesium on zinc electrodeposition was studied using the electrochemical techniques of galvanostatic deposition and cyclic voltammetry. Additions of nickel, magnesium or both cations in zinc sulfate electrolyte resulted in a marginal increase in current efficiency. Addition of nickel or magnesium polarizes the cathode; however, the extent of polarization in the presence of magnesium is more than that of nickel. Addition of magnesium to the zinc electrolyte caused zinc reduction at a more negative potential. The addition of nickel to the zinc electrolyte increased the current density of the anodic peaks, thus increasing the dissolution of zinc and hydrogenated phases. The addition of nickel to the zinc and magnesium solutions decreased the nucleation loop, facilitating zinc deposition.

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The cyclic oxidation behavior of an experimental stainless ferritic steel, without molybdenum and with copper-aluminum-titanium-lanthanum additions, developed for solid oxide fuel cell applications, was evaluated and compared with the oxidation behavior of commercial austenitic and ferritic stainless steels. For the cyclic oxidation tests, the steel samples were tested at temperatures ranging from 600 to 800°C. The experimental ferritic stainless steel showed the highest cyclic oxidation behavior among the studied steels at 700°C and 800°C, presenting a parabolic and logarithmic kinetics, respectively.

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