Leaching (chemistry)

Specific extraction methods depend on the soluble characteristics relative to the sorbent material such as concentration, distribution, nature, and size.

[5] Leaching can also be applied affectedly to enhance water quality and contaminant removal,[1][6] as well as for disposal of hazardous waste products such as fly ash,[7] or rare earth elements (REEs).

[3] Bioleaching is a term that describes the removal of metal cations from insoluble ores by biological oxidation and complexation processes.

[6] This process is done in most part to extract copper, cobalt, nickel, zinc, and uranium from insoluble sulfides or oxides.

[7] Though the re-use of fly ash in other materials such as concrete and bricks is encouraged, still much of it in the United States is disposed of in holding ponds, lagoons, landfills, and slag heaps.

[7] These disposal sites all contain water where washing effects can cause leaching of many different major elements, depending on the type of fly ash and the location where it originated.

[4][11] The leaching is typically described by solute transport models, such as Darcy's Law, mass flow expressions, and diffusion-dispersion understandings.

[4] Diffusion is controlled by other factors such as pore size and soil skeleton, tortuosity of flow path, and distribution of the solvent (water) and solutes.

In the field of mineralogy, acid leaching is common to extract Metals such as vanadium, Cobalt, Nickel, Manganese, Iron etc.