diatomaceous earth

diatomaceous earth
a fine siliceous earth composed chiefly of the cell walls of diatoms: used in filtration, as an abrasive, etc. Also called diatomite /duy at"euh muyt'/, kieselguhr.
[1880-85]

* * *

Light-coloured, porous, and friable sedimentary rock composed of the frustrules (silicate cell walls) of diatoms.

It is used in industrial filtration applications; as a filler or extender in paper, paint, brick, tile, ceramics, linoleum, plastic, soap, detergent, and other products; in insulation for boilers, blast furnaces, and other high-temperature devices; as a sound insulator; and as a carrier for herbicides and fungicides. The oldest and best-known commercial use is as a very mild abrasive in metal polishes and toothpaste. Large deposits occur in California, Nevada, Washington, and Oregon; other sources are Denmark, France, Russia, and Algeria.

* * *

also called  Kieselguhr,  

      light-coloured, porous, and friable sedimentary rock that is composed of the siliceous shells of diatoms, unicellular aquatic plants of microscopic size. It occurs in earthy beds that somewhat resemble chalk, but it is much lighter than chalk and will not effervesce in acid. Under a high-powered microscope the form of the diatoms can be distinguished. When well hardened, it is called diatomite. Similar siliceous rocks, called radiolarian earth and radiolarite, are formed from the latticelike opaline skeletons of Radiolaria.

      Diatomaceous earth, formerly used principally as a filter in clarifying sugar and syrups, has been adapted to almost all industrial filtration applications, including the processing of oils, alcoholic and nonalcoholic beverages, antibiotics, solvents, and chemicals. A second major use is as a filler or extender in paper, paint, brick, tile, ceramics, linoleum, plastic, soap, detergent, and a large number of other products. It also is used in the insulation of boilers, blast furnaces, and other devices in which high temperatures are maintained; at temperatures higher than 525° C (about 1,000° F) diatomaceous earth is a more efficient insulator than asbestos or magnesia because it is more resistant to shrinkage and does not fail at red heat. Other uses include sound insulation and vehicles for herbicides and fungicides. The oldest and best known commercial use is as a very mild abrasive in metal polishes and toothpaste.

      The largest deposit worked in the United States is in northern Santa Barbara County, California, where beds more than 300 metres (1,000 feet) thick extend over several square miles and vary from soft earth to hard, compact rock that can be sawed into blocks; other production has come from Nevada, Washington, and Oregon. Denmark, France, and Russia have well-developed diatomaceous earth industries, and numerous deposits exist in Algeria.

* * *


Universalium. 2010.

Игры ⚽ Нужен реферат?

Look at other dictionaries:

  • diatomaceous earth — di a*to*ma ceous earth (Geol.), a deposit of fine, usually white, siliceous material, composed mainly of the shells of the microscopic plants called diatoms; also called {infusorial earth}, {kieselguhr}, and {diatomite}. It is used in polishing… …   The Collaborative International Dictionary of English

  • diatomaceous earth — n DIATOMITE * * * infusorial e …   Medical dictionary

  • Diatomaceous earth — A sample of diatomaceous earth Diatomaceous earth (  / …   Wikipedia

  • diatomaceous earth — Infusorial In fu*so ri*al, a. (Zo[ o]l.) Belonging to the Infusoria; composed of, or containing, Infusoria; as, infusorial earth. [1913 Webster] {Infusorial earth} (Geol.), a deposit of fine, usually white, siliceous material, composed mainly of… …   The Collaborative International Dictionary of English

  • diatomaceous earth — A mineral formed by deposition of siliceous remains of diatoms, microscopic aquatic life forms. Diatomaceous earth has long been used as a catalyst support. Also known as Kieselguhr …   Petroleum refining glossary

  • diatomaceous earth —    1) [ geology ]    A lacustrine or marine geologic deposit of fine, grayish, siliceous material composed chiefly or wholly of the remains of diatoms. It may occur as a powder or a rigid material (i.e., diatomite).    GSST    2) [ Soil Taxonomy… …   Glossary of landform and geologic terms

  • diatomaceous earth — diatomitas statusas T sritis ekologija ir aplinkotyra apibrėžtis Silicitų grupės silpnai cementuota, labai poringa, lengva nuosėdinė uoliena. Susidariusi iš sucementuotų titnagdumblių dvinarių opalinių kiautelių (60–95 % masės sudaro opalas).… …   Ekologijos terminų aiškinamasis žodynas

  • diatomaceous earth — di′atoma′ceous earth′ n. gel a fine siliceous earth composed chiefly of the cell walls of diatoms and used in filtration. Also called di•at•o•mite [[t]daɪˈæt əˌmaɪt[/t]] • Etymology: 1880–85 …   From formal English to slang

  • diatomaceous earth —    A light colored, soft, siliceous earth composed of the shells of diatoms, a form of algae. Some deposits are of lake origin but the largest are marine [6] …   Lexicon of Cave and Karst Terminology

  • diatomaceous earth — /ˌdaɪətəmeɪʃəs ˈɜθ/ (say .duyuhtuhmayshuhs erth) noun a fine siliceous earth composed chiefly of cell walls of diatoms, used in filtration, as an abrasive, etc.; kieselguhr. Also, diatomite /daɪˈætəmaɪt/ (say duy atuhmuyt) …  

Share the article and excerpts

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