Lixiviation

Lixiviation: Inorganic Chemistry for Industries

Lixiviation is the process of separating soluble from insoluble substances by dissolving the former in water or some other solvent.
The mixture of substances is put into a suitable vessel, the solvent poured over it, and the whole allowed to stand until a strong solution is obtained, which is then drawn off from the residue. This process is repeated as often as necessary, until the desired amount of soluble matter has been removed. Sometimes the mixture is put into baskets, or on gratings, which are suspended in tanks of water. The solution being denser than the solvent, sinks to the bottom as it forms, and water comparatively free from dissolved material is thus constantly brought into contact with the substance to be lixiviated. The insoluble substance remains on the grating or in the baskets.
When desired, the soluble material may be recovered from the solution by evaporation or precipitation. Extraction is the term usually employed when some solvent other than water is used in lixiviating. Thus we speak of extraction by steam, alcohol, carbon disulphide, etc.

The above information on chemistry subjects is as they were described in the past centuries.