Hydrometallurgiaan

Hydrometallurgiaan, in Dutch referring to hydrometallurgy, is the branch of extractive metallurgy that deals with recovering metals from ores, concentrates, and other materials through aqueous chemical processes. Metals are dissolved in water-based solutions and subsequently separated, purified, and recovered, typically at ambient or modest temperatures. Hydrometallurgy complements pyrometallurgy and is particularly effective for fine-grained or low-grade ores and for recycling streams.

Core operations include leaching to dissolve metals, followed by purification and transfer of the metal into an active solution using solvent extraction or ion exchange. The metal is then recovered by electrochemical deposition (electrowinning) or precipitation. Leaching methods include heap, in situ, or stirred-tank approaches, chosen for selectivity, ore characteristics, and environmental considerations. Integrated flowsheets may combine leaching, solvent extraction, and electrowinning (SX–EW) for metals such as copper.

Applications span primary metal production and recycling, including copper, nickel, zinc, cobalt, uranium, gold, and rare earth elements, as well as recovery from electronic waste and spent catalysts. Hydrometallurgical techniques are especially valuable for low-grade or complex ores and for processing secondary materials where high-temperature methods are impractical.

Environmental and economic aspects focus on water use, chemical management, and containment of effluents, with a goal of reducing energy consumption relative to pyrometallurgy. Developments in biohydrometallurgy employ microorganisms to facilitate metal dissolution, expanding possibilities for difficult feeds and sustainable processing within a circular economy.