Hydrometallurgy is the technology where metals are extracted into an aqueous solution and subsequently recovered by a variety of methods. Hydrometallurgy is mainly based on the science of inorganic and physical chemistry.
The hydrometallurgical unit processes are generally abiotic but under some circumstances microbes are used to enhance the chemical processes. Biohydrometallurgy is a subfield within hydrometallurgy which includes aspects of microbes and biotechnology.
Even though hydrometallurgy strictly defined only deals with applications of economical interest, research and knowledge about natural geochemical processes involving metals probably relate to a better comprehension of hydrometallurgy. Natural processes like metal transformations may be interesting in their own right but also in order to better understand environmental impacts by mining activities and to invent new applications of economical interest.