INTERACTIONS AT METAL INTERFACES-A COMPARISON OF VARIOUS MODEL APROACHES

Many of the mineral processing techniques depend on the interfacial interactions between solid and liquid, essentially water. The interfacial surface tension control those two phases, while the surface energy is one of the main components in understanding the interface process. The most common standard method used for determining the surface energy is contact angle method that characterizes the properties of the solids. This paper reports a description of the theory of interactions occurring at the metal interfaces and the experimental methods available for assessing those interactions. We made a review and a direct comparison of widely used models for the calculation of surface energy of solids such as Owens-Wendt-Rabel-Kaelble, Wu and Acid-Base models in order to evaluate their advantages and disadvantages. The particular site of Trepça Mining Complex jarosite waste material was used as an example for reviewing these interactions. In this case a contact angle between the surface and the edge of droplets of water, formamide, diiodo methane is measured. We conclude that values of contact angle provide an indication of the degree of surface hydrophobicity / hidrophilicity character. This method is an important parameter of processing the jarosite waste material in Trepca.