Diatomaceous earth

Diatomite rock sample from Sisquoc Formation
Scanning electron micrograph of diatomaceous earth

Diatomaceous earth (/ˌdaɪ.ətəˈmeɪʃəs/ DY-ə-tə-MAY-shəs), also known as diatomite (/daɪˈætəmaɪt/ dy-AT-ə-myte), celite, or kieselguhr, is a naturally occurring, soft, siliceous sedimentary rock that can be crumbled into a fine white to off-white powder. It has a particle size ranging from more than 3 mm to less than 1 μm, but typically 10 to 200 μm.[1] Depending on the granularity, this powder can have an abrasive feel, similar to pumice powder, and has a low density as a result of its high porosity. The typical chemical composition of oven-dried diatomaceous earth is 80–90% silica, with 2–4% alumina (attributed mostly to clay minerals), and 0.5–2% iron oxide.[2]

Diatomaceous earth consists of the fossilized remains of diatoms, a type of hard-shelled microalgae, that have accumulated over millions of years.[3] It is used as a filtration aid, mild abrasive in products including metal polishes and toothpaste, mechanical insecticide, absorbent for liquids, matting agent for coatings, reinforcing filler in plastics and rubber, anti-block in plastic films, porous support for chemical catalysts, cat litter, activator in coagulation studies, a stabilizing component of dynamite, a thermal insulator, and a soil for potted plants and trees as in the art of bonsai.[4][5] It is also used in gas chromatography packed columns made with glass or metal as stationary phase.

  1. ^ Dobrosielska, Marta; Dobrucka, Renata; Brząkalski, Dariusz; Frydrych, Miłosz; Kozera, Paulina; Wieczorek, Monika; Jałbrzykowski, Marek; Kurzydłowski, Krzysztof J.; Przekop, Robert E. (May 18, 2022). "Influence of Diatomaceous Earth Particle Size on Mechanical Properties of PLA/Diatomaceous Earth Composites". Materials. 15 (10): 3607. Bibcode:2022Mate...15.3607D. doi:10.3390/ma15103607. ISSN 1996-1944. PMC 9145730. PMID 35629631.
  2. ^ Antonides, Lloyd E. (1997). Diatomite (PDF). USGS. Retrieved December 12, 2010.
  3. ^ Rojht, Helena; Horvat, Aleksander; Athanassiou, Christos G.; Vayias, Bill J.; Tomanović, Željko; Trdan, Stanislav (2010–2012). "Impact of geochemical composition of diatomaceous earth on its insecticidal activity against adults of Sitophilus oryzae (L.) (Coleoptera: Curculionidae)". Journal of Pest Science. 83 (4): 429–436. doi:10.1007/s10340-010-0313-6. ISSN 1612-4758. S2CID 23110767.
  4. ^ Reka, Arianit A.; Pavlovski, Blagoj; Ademi, Egzon; Jashari, Ahmed; Boev, Blazo; Boev, Ivan; Makreski, Petre (December 31, 2019). "Effect Of Thermal Treatment Of Trepel At Temperature Range 800-1200˚C". Open Chemistry. 17 (1): 1235–1243. doi:10.1515/chem-2019-0132.
  5. ^ Reka, Arianit; Anovski, Todor; Bogoevski, Slobodan; Pavlovski, Blagoj; Boškovski, Boško (December 29, 2014). "Physical-chemical and mineralogical-petrographic examinations of diatomite from deposit near village of Rožden, Republic of Macedonia". Geologica Macedonica. 28 (2): 121–126.