Cobalt(II) oxide: Difference between revisions

From Citizendium
Jump to navigation Jump to search
imported>Paul Derry
No edit summary
imported>Paul Derry
(→‎Ceramics: Rewrite and inclusion of new materia.)
Line 7: Line 7:
==Ceramics==
==Ceramics==


Cobalt(II) Oxide has been used for centuries as a coloring agent on kiln fired ceramic glazes, the earliest examples go back to 12th century German pottery. The additive produces a deep shade of blue once it has been fired in a kiln that is often referred to as cobalt blue.
Cobalt(II) Oxide has been used for centuries as a coloring agent on kiln fired ceramic glazes, the earliest examples go back to the beginnings of kiln fired pottery. Cobalt(II) Oxide colorants are stable and retain their coloration indefinitely. The oxide is one of the most powerful colorants commonly used in the making of glazes and slips and requires only 1 part oxide to 100,000 parts glazing compound to produce the deep blue shade commonly referred to as <span style="background-color: #0047AB; padding:4px; color: #ffffff">cobalt blue</span>. By varying the temperature of the kiln, the potter can adjust the coloring of the oxide ranging anywhere from the familiar blue, to a shade nearing black. <ref>Zamek, Jeff: "A Problem With Cobalt?" ''Ceramics Today'' http://www.ceramicstoday.com/articles/zamek_cobalt.htm</ref>


==Industrial Uses==
==Industrial Uses==

Revision as of 15:58, 17 February 2007

Cobalt(II) oxide is a blackish gray powder used extensively in the ceramics industry as an additive to create blue colored glazes and enamels as well as in the chemical production industry for producing cobalt(II) salts.

Cobalt(II) oxide is a product of Cobalt(II,III) oxide decomposing at 895 °C through the reaction:

2 Co3O4(s) → 6 CoO(s) + O2(g)

Ceramics

Cobalt(II) Oxide has been used for centuries as a coloring agent on kiln fired ceramic glazes, the earliest examples go back to the beginnings of kiln fired pottery. Cobalt(II) Oxide colorants are stable and retain their coloration indefinitely. The oxide is one of the most powerful colorants commonly used in the making of glazes and slips and requires only 1 part oxide to 100,000 parts glazing compound to produce the deep blue shade commonly referred to as cobalt blue. By varying the temperature of the kiln, the potter can adjust the coloring of the oxide ranging anywhere from the familiar blue, to a shade nearing black. [1]

Industrial Uses

As stated earlier, cobalt(II) oxide is used in the production of cobalt(II) salts such as CoCl2 and Co(NO3)2.

Health Issues

References

1. http://www.ceramicstoday.com/articles/zamek_cobalt.htm

  1. Zamek, Jeff: "A Problem With Cobalt?" Ceramics Today http://www.ceramicstoday.com/articles/zamek_cobalt.htm