Theoretical estimates and kinetic analyses of leaching ores were found to be equally important, according to researchers. In addition, during this period, the concept of species adsorption on mineral surfaces has dominated our understanding of the underlying mechanisms of most reactions. This might have happened as a result of the fact that many scientists at the time worked in the mineral dressing sector and were influenced by flotation theories. However, once lattice flaws and minerals' semiconductivity were discovered and their importance in extractive metallurgy was recognized, it became necessary to explain the leaching processes in the context of these modern notions. Sulphides like those of copper, lead, and zinc, as well as oxides like those of uranium, are two categories of semiconducting minerals that are important in metallurgy.