Studies of potential impacts provided by the presence of magnesium in iron oxide on iron electrodeposition from ceramic powder suspensions under alkaline conditions. The presented data allows one to understand if alternative iron oxide feedstocks rich in -Mg content can be used as a raw material for Fe electrodeposition. In this case, the iron oxide-based magnesium spinel allows one to study typical iron-rich waste found in the metallurgical industries. The data was obtained by electrochemical tests performed by a potentiostat and recorded as .xlsx files. This data was recalculated, taking into account the working electrode area. XRD data (.xlsx) and SEM (.jpg) images were collected according to each type of analysis. The corresponding experimental conditions have never been tried so far. The data was obtained by experimental tests of Fe electrodeposition using Fe2.3M0.7O4 bulk cathodes and suspensions. The presented data is useful for screening potential iron oxide feedstocks for further tests at the SIDERWIN pilot scale.