Bone char

Bone char
"Bone black" redirects here. For the memoir by bell hooks, see Bone Black: memories of girlhood.

Bone char, also known as bone black, ivory black, animal charcoal, or abaiser, is a granular material produced by charring animal bones. To prevent the spread of mad-cow disease, the skull and spine are never used.[1] The bones are heated to high temperatures—in the range of 400 to 500 °C (752 to 932 °F)— in an oxygen-depleted atmosphere to control the quality of the product as related to its adsorption capacity for applications such as defluoridation of water and removal of heavy metals from aqueous solutions. The quality of the bone char can be easily determined by its color. Black charcoals are usually undercharred bones that still contain organic impurities which may impart undesired odor and color to treated waters. White bone chars are overcharred bones that present low fluoride removal capacity. Grey-brownish bone char are the best quality chars for absorption applications. The quality of the bone chars is usually controlled by the amount of oxygen present in the charring atmosphere. It consists mainly of calcium phosphate and a small amount of carbon. Bone chars usually have lower surface areas than activated carbons, but present high adsorptive capacities for copper, zinc, and cadmium.[2][3]

Uses

  • Bone char is used to remove fluoride from water and to filter aquarium water.
  • It is often used in the sugar refining industry for decolorizing[4] (a process patented by Louis Constant in 1812).[5]
  • It is used to refine crude oil in the production of petroleum jelly.
  • Bone char is also used as a black pigment. It is sometimes used for artist's paint, printmaking, calligraphic and drawing inks as well as other artistic applications because of its deepness. Ivory black is an artists' pigment formerly made by grinding charred ivory in oil. Today it is considered a synonym for bone char. Actual ivory is no longer used because of the expense, and because animals who are natural sources of ivory are subject to international control as endangered species.

In popular culture

  • The production of bone char was featured on the Discovery Channel's TV series Dirty Jobs, on episode 19 of season 5, "Bone Black", originally broadcast on 9 February 2010.[1]
  • Human bone char, referred to as "bone charcoal," is mentioned in Thomas Pynchon's novel The Crying of Lot 49. The bones come from US soldiers who died in combat during WWII and were buried in a lake in Italy, the char is used for filters in cigarettes.

References

  1. ^ a b "Dirty Jobs: Episode Guide"
  2. ^ Wilson, J.A., Pulford, I.D. and Thomas, S. (2003). Sorption of Cu and Zn by bone charcoal. 25. Environmental Geochemistry and Health. pp. 51–56. 
  3. ^ Choy, K.K.H. and McKay, G. (2005). Sorption of metal ions from aqueous solution using bone char. 31. Environment International. pp. 845–854. 
  4. ^ Yacoubou, MS, Jeanne (2007). "Is Your Sugar Vegan? An Update on Sugar Processing Practices" (PDF). Vegetarian Journal (Baltimore, MD: The Vegetarian Resource Group) 26 (4): 16–20. http://www.vrg.org/journal/vj2007issue4/vj2007issue4.pdf. Retrieved 2007-04-04. 
  5. ^ Thorpe, Thomas Edward (1912). A dictionary of applied chemistry, volume 1. Longmans, Green and Co.. pp. 264. http://books.google.com/books?id=6XfPAAAAMAAJ&pg=PA264&dq=Louis+Constant+in+1812#v=onepage&q=Louis%20Constant%20in%201812&f=false. 

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Look at other dictionaries:

  • bone char — noun black substance containing char in the form of carbonized bone; used as a black pigment • Syn: ↑bone black, ↑animal black, ↑animal charcoal • Hypernyms: ↑char * * * noun see bone black …   Useful english dictionary

  • bone char — noun see bone black …   New Collegiate Dictionary

  • bone black — [bōn′blak΄] a fine charcoal made by burning animal bones in closed containers: used as a pigment, in refining sugar, etc.: also boneblack [bōn′blak΄] n. * * * ▪ chemistry also called  Bone Char, or Bone Charcoal,         a form of charcoal (q.v.) …   Universalium

  • Bone oil — may refer to: *Neatsfoot oil, a yellow oil used as a conditioning, softening and preservative for leather *Dippel s oil, a nitrogenous by product of the dry distillation manufacture of bone char …   Wikipedia

  • bone black — noun black substance containing char in the form of carbonized bone; used as a black pigment • Syn: ↑bone char, ↑animal black, ↑animal charcoal • Hypernyms: ↑char * * * noun or bone …   Useful english dictionary

  • bone black — noun Date: 1815 the black residue chiefly of tribasic calcium phosphate and carbon from bones calcined in closed vessels used especially as a pigment or as a decolorizing adsorbent in sugar manufacturing called also bone char …   New Collegiate Dictionary

  • char — char1 /chahr/, v., charred, charring, n. v.t. 1. to burn or reduce to charcoal: The fire charred the paper. 2. to burn slightly; scorch: The flame charred the steak. v.i. 3. to become charred. n. 4. a charred material or surface. 5. charcoal. 6.… …   Universalium

  • Char — /shannrdd/, n. René /rddeuh nay /, born 1907, French poet. * * * Any of several freshwater food and game fishes (genus Salvelinus) of the salmon family, distinguished from the similar trout by light, rather than black, spots; by a boat shaped,… …   Universalium

  • Sucrose — Sucrose …   Wikipedia

  • animal black — noun black substance containing char in the form of carbonized bone; used as a black pigment • Syn: ↑bone black, ↑bone char, ↑animal charcoal • Hypernyms: ↑char * * * noun : a black pigment made by carbonizing animal matter: as …   Useful english dictionary

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