The solution is then collected and processed. The Beverley uranium deposit is an example of in-situ leaching and also Trojan Mine in Zimbabwe. Heap leaching
In heap leaching processes, crushed (and sometimes agglomerated) ore is piled in a heap which is lined with an impervious layer. Leach solution is sprayed over the top of the heap, and allowed to percolate downward through the heap. The heap design usually incorporates collection sumps, which allow the "pregnant" leach solution (i.e. solution with dissolved valuable metals) to be pumped for further processing. An example is gold cyanidation, where pulverized ores are extracted with a solution of sodium cyanide, which, in the presence of air, dissolves the gold, leaving behind the nonprecious residue. Vat leaching
Vat leaching involves contacting material, which has usually undergone size reduction and classification, with leach solution in large vats. Tank leaching
Stirred tank, also called agitation leaching, involves contacting material, which has usually undergone size reduction and classification, with leach solution in agitated tanks. The agitation can enhance reaction kinetics by enhancing mass transfer. Tanks are often configured as reactors in series. Autoclave leaching
Autoclave reactors are used for reactions at higher temperatures, which can enhance the rate of the reaction. Similarly,  autoclaves enable the use of gaseous reagents in the system. Solution concentration and purification
After leaching, the leach liquor must normally undergo concentration of the metal ions that are to be recovered. Additionally, undesirable metal ions sometimes require removal.
Hydrometallurgy is a technique within the field of extractive metallurgy, the obtaining of metals from their ores. Hydrometallurgy involve the use of aqueous solutions for the recovery of metals from ores, concentrates, and recycled or residual materials. Processing techniques that complement hydrometallurgy are pyrometallurgy, vapour metallurgy, and molten salt electrometallurgy. Hydrometallurgy is typically divided into three general areas:

Leaching
Solution concentration and purification
Metal or metal compound recovery

Leaching
Leaching involves the use of aqueous solutions to extract metal from metal bearing materials which is brought into contact with a material containing a valuable metal. The first examples come from 11-12th centuries China where it was applied to extraction of copper and accounted for a significant share of total copper production. In the 17th century it was used for the same purposes in Germany and Spain.The lixiviant solution conditions vary in terms of pH, oxidation-reduction potential, presence of chelating agents and temperature, to optimize the rate, extent and selectivity of dissolution of the desired metal component into the aqueous phase. Through the use of chelating agents, one can selectively extract certain metals. Such chelating agents are typically amines of schiff bases.The five basic leaching reactor configurations are in-situ, heap, vat, tank and autoclave. In-situ leaching
In-situ leaching is also called "solution mining." This process initially involves drilling of holes into the ore deposit. Explosives or hydraulic fracturing are used to create open pathways within the deposit for solution to penetrate into. Leaching solution is pumped into the deposit where it makes contact with the ore.