Leaching is often equated with wet metallurgy in the mining industry. However, leaching is only one of the operations included in hydrometallurgy. Moreover, the process of hydrometallurgy can be carried out without leaching, for example, the precipitation of magnesium oxide from seawater using burned dolomite, a major source of magnesium. Other major hydrometallurgical operations include liquid-solid separation, replacement, crystallization, precipitation, oxidation or reduction, ion exchange, solvent extraction, electrowinning or electrolytic refining, which are commonly characterized by a water-solute-solid system of minerals.
As a citation for evaluating the potential applications and limitations of hydrometallurgy, this paper reviews some of the key ancient and modern developments that have led to its current widespread use. Since both proponents and opponents of hydrometallurgy are essentially involved in some specific applications, this paper also addresses some of the operations that can illustrate the advantages and disadvantages of hydrometallurgy, (as well as some of the ancillary roles that have an impact on hydrometallurgy).