leach

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The removal of a soluble fraction, in the form of a solution, from an insoluble, permeable solid with which it is associated. The separation usually involves selective dissolving, with or without diffusion, but in the extreme case of simple washing it consists merely of the displacement (with some mixing) of one interstitial liquid by another with which it is miscible. The soluble constituent may be solid (as the metal leached from ore) or liquid (as the oil leached from soybeans).

Leaching is closely related to solvent extraction, in which a soluble substance is dissolved from one liquid by a second liquid immiscible with the first. Both leaching and solvent extraction are often called extraction. Because of its variety of applications and its importance to several ancient industries, leaching is known by a number of other names: solid-liquid extraction, lixiviation, percolation, infusion, washing, and decantation-settling. The liquid used to leach away the soluble material (the solute) is termed the solvent. The resulting solution is called the extract or sometimes the miscella.

Leaching processes fall into two principal classes: those in which the leaching is accomplished by percolation (seeping of solvent through a bed of solids), and those in which particulate solids are dispersed into the extracting liquid and subsequently separated from it. In either case, the operation may be a batch process or continuous. See also Extraction; Filtration; Solvent extraction.

verb

To flow or leak out or emit something slowly: bleed, exude, ooze, percolate, seep, transpire, transude, weep. See move/halt, solid/liquid/consistency.

The movement of water down the soil profile. This results in the movement of cations, sesquioxides, clay colloids, and humus to the lower soil horizons. Specific types of leaching include: lixiviation—the removal of the soluble salts containing metallic cations; the removal of chelates; lessivage; and, in tropical soils, desilication.

1. The process of separating a liquid from a solid (as in waste liquid) by percolation into the surrounding soil.
2. The process of allowing soluble nutrients to move downward and percolate through the surrounding soil.

The loss of nutrients when rain or irrigation carries them down through the soil and out of the root zone.

• Processes, Phenomena, Events, and Techniques - leaching: washing away of soluble minerals, esp. alkalines, from upper layers of soil by water
• Soils and Soil Management - leaching: washing away of soluble plant foods from topsoil by rain
• Practice, Tools, and Techniques - leaching: loss of soluble matter from soil due to filtering through of water

Look up leaching in Wiktionary, the free dictionary.

In general, leaching is the extraction of certain materials from a carrier into a liquid (usually, but not always a solvent). Specifically, it may refer to:

• Leaching (agriculture), the loss of water-soluble plant nutrients from the soil; or applying a small amount of excess irrigation to avoid soil salinity
• Leaching (chemistry), the process of extracting minerals from a solid by dissolving them in a liquid
• Leaching (metallurgy), a widely used extractive metallurgy technique which converts metals into soluble salts in aqueous media
  • Dump leaching, an industrial process to extract metals from ore taken directly from the mine and stacked on the leach pad without crushing
  • Heap leaching, an industrial process to extract metals from ore which has been crushed into small chunks
  • Tank leaching, a hydrometallurgical method of extracting valuable material from ore
  • In-situ leaching, a process of recovering minerals such as copper and uranium through boreholes drilled into the deposit
• Leaching (pedology), the loss of mineral and organic solutes due to percolation from soil
• Bioleaching, the extraction of specific metals from their ores through the use of bacteria

• In cooking, leaching generally refers to Parboiling.

See also

• Leachate, the liquid that drains or 'leaches' from a landfill
• Leach (disambiguation)
• Leech (disambiguation)

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Dansk (Danish)
v. tr. - filtrere, udlude, udvaske
v. intr. - blive udludet
n. - filtrering

Nederlands (Dutch)
uitlogen, percoleren

Français (French)
v. tr. - lessiver
v. intr. - s'infiltrer (une substance)
n. - fosse

Deutsch (German)
v. - durchsickern lassen, auslaugen
n. - Auslaugen, Blutegel

Ελληνική (Greek)
v. - διυλίζω, φιλτράρω, απονιτρώνω ή εκπλένω (μετάλλευμα), (μτφ.) στραγγίζω
n. - απόσταξη, φιλτράρισμα, διϋλιση, απόσταγμα, φίλτρο, αποστακτήρας

Italiano (Italian)
biancheggiare

Português (Portuguese)
v. - fazer lixívia
n. - lixívia (f) (Quím.)

Русский (Russian)
щелок, раствор соли, выщелачивать

Español (Spanish)
v. tr. - lixiviar, colar la ropa
v. intr. - lixiviar, colar la ropa
n. - cenizas de lejía, colada

Svenska (Swedish)
v. - filtrera, luta ut, laka ur, vaska ur
n. - lutkärl, lutbalja, lutaska, lake, lösning

中文（简体）(Chinese (Simplified))
过滤, 水浸, 萃取, 被过滤, 被滤掉, 被溶滤, 滤灰槽, 过滤器

中文（繁體）(Chinese (Traditional))
v. tr. - 過濾, 水浸, 萃取
v. intr. - 被過濾, 被濾掉, 被溶濾
n. - 過濾, 濾灰槽, 篩檢程式

한국어 (Korean)
v. tr. - 거르다, 물에 담가 우리다
v. intr. - 여과되다, 스며 나오다, 걸러지다
n. - 거르기, 여과된 액체, 잿물, 여과기

日本語 (Japanese)
v. - こす, 水でこす, こして取る, 浸出する
n. - ろ過

العربيه (Arabic)
‏(فعل) يرشح, يصفي, يروق, يرتشح (الاسم) وعاء الترشيح, عمليه الترشيح‏

עברית (Hebrew)
v. tr. - ‮סינן‬
v. intr. - ‮שטף ע"י חלחול, סילק חומר מסיס‬
n. - ‮מסנן, מסננת, סינון, תמיסה, חומר שעבר תהליך סינון‬

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