flotation


flotation
/floh tay"sheuhn/, n.
1. an act or state of floating.
2. the launching of a commercial venture, bond issue, loan, etc.
3. Metall. a process for separating the different minerals in a mass of powdered ore based on their tendency to sink in, or float on, a given liquid.
4. the science of floating bodies.
Also, floatation.
[1800-10; FLOAT + -ATION; cf. F flottaison (see FLOTSAM)]

* * *

Most widely used process for extracting many minerals from their ores.

The method separates and concentrates ores by altering their surfaces so that they are either repelled or attracted by water. Unwetted particles, which adhere to air that is bubbled through the water, will float in the froth, while wetted particles will sink. The process was developed on a commercial scale early in the 20th century to remove very fine mineral particles that formerly had gone to waste in gravity concentration plants. With its use to concentrate copper, lead, and zinc minerals, which commonly accompany one another in their ores, many complex ore mixtures formerly of little value have become major sources of certain metals.

* * *

 in mineral processing, method used to separate and concentrate ores by altering their surfaces to a hydrophobic or hydrophilic condition—that is, the surfaces are either repelled or attracted by water. The flotation process was developed on a commercial scale early in the 20th century to remove very fine mineral particles that formerly had gone to waste in gravity concentration plants. Flotation has now become the most widely used process for extracting many minerals from their ores.

      Most kinds of minerals require coating with a water repellent to make them float. By coating the minerals with small amounts of chemicals or oils, finely ground particles of the minerals remain unwetted and will thus adhere to air bubbles. The mineral particles are coated by agitating a pulp of ore, water, and suitable chemicals; the latter bind to the surface of the mineral particles and make them hydrophobic. The unwetted particles adhere to air bubbles and are carried to the upper surface of the pulp, where they enter the froth; the froth containing these particles can then be removed. Unwanted minerals that naturally resist wetting may be treated so that their surfaces will be wetted and they will sink.

      This ability to modify the floatability of minerals has made possible many otherwise difficult separations that are now common practice in modern mills. Flotation is widely used to concentrate copper, lead, and zinc minerals, which commonly accompany one another in their ores. Many complex ore mixtures formerly of little value have become major sources of certain metals by means of the flotation process.

* * *


Universalium. 2010.

Look at other dictionaries:

  • Flotation — Flo*ta tion, n. [Cf. F. flottation a floating, flottaison water line, fr. flotter to float. See {Flotilla}.] 1. The act, process, or state of floating. [1913 Webster] 2. The science of floating bodies. [1913 Webster] 3. (Com. & Finance) Act of… …   The Collaborative International Dictionary of English

  • Flotation — Flotation. См. Флотация. (Источник: «Металлы и сплавы. Справочник.» Под редакцией Ю.П. Солнцева; НПО Профессионал , НПО Мир и семья ; Санкт Петербург, 2003 г.) …   Словарь металлургических терминов

  • flotation — When a company s shares are admitted to listing on the Official List and traded on a recognised investment exchange. Related links exit bridge financing Practical Law Dictio …   Law dictionary

  • flotation — 1850s, from FLOAT (Cf. float) + ATION (Cf. ation). Spelling influenced by French (Cf. FLOATATION (Cf. floatation)) …   Etymology dictionary

  • flotation — is now the dominant spelling for the word meaning ‘the process of launching or financing a business or commercial enterprise’. It has replaced the earlier form floatation, on the analogy of words such as flotilla, flotsam, etc …   Modern English usage

  • flotation — (also floatation) ► NOUN 1) the action of floating or capacity to float. 2) the process of offering a company s shares for sale on the stock market for the first time …   English terms dictionary

  • flotation — [flō tā′shən] n. [earlier floatation, respelled as if < Fr flottaison] 1. the act or condition of floating; specif., the act of beginning or financing a business, etc., as by selling an entire issue of bonds, securities, etc. 2. the capacity… …   English World dictionary

  • Flotation — Flotationszelle Flotation (von englisch: to float – schwimmen) ist ein physikalisch chemisches Trennverfahren für feinkörnige Feststoffe aufgrund der unterschiedlichen Oberflächenbenetzbarkeit der Partikel. Dabei macht man sich zunutze, dass… …   Deutsch Wikipedia

  • flotation — The occasion on which a company s shares are offered on the market for the first time. Exchange Handbook Glossary flotation or floatation Flotation is the process of making a company s shares available to the general public by obtaining a… …   Financial and business terms

  • Flotation — Despite the Southwest Airlines spelling of the word, the more common spelling is floatation . Flotation may refer to:*Buoyancy, the phenomenon that keeps ships from sinking *Flotation process, in process engineering, a method for the separation… …   Wikipedia


Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.