Electrochemical Dissolution of Magnetite in Acid Solutions

The present paper deals with the electrochemical behavior of magnetite microcrystals in an acid medium. A voltammetric method employing a carbon-paste electroactive electrode (CPEE) with an organic binder was used. It was found that the cathodic voltammograms, which were recorded at different scan rates, formed a set bounded in the space of i–E parameters by a “generalizing” voltammetric curve corresponding to the “effective” potential scan rate νeff. In other words, all curves are situated under one enveloping curve, just as the smaller dolls sit in the largest doll of a “Russian doll”. “Reverse” currents (a cathodic current in the anodic direction of the potential scan) were observed on the cyclic voltammogram. Forward and reverse currents obey the same laws and have one and the same “generalizing” curve, which could be taken as the magnetite characteristic.