RAW MATERIALS AND OXIDES
RAW MATERIALS AND OXIDES
RAW MATERIALS AND OXIDES

REFSAN COBALT OXIDE (60206)

Brand : REFSAN
Price : 91,52TL
ÇOKALAZÖDE BOYA

COBALT (II,III) OXIDE (72 % Co)

Cobalt(II,III) oxide is an inorganic compound with the formula Co3O4. It is one of two well-characterized cobalt oxides. It is a black antiferromagnetic solid. As a mixed-valence compound, its formula is sometimes written as CoIICoIII2O4 and sometimes as CoO•Co2O3

CoO is a metallic coloring oxide that produces blue in glazes at all temperatures (unless in very high percentages where it will be black). Black Cobalt Oxide is a key source of CoO used in glazes, glass, and enamels. Cobalt is the most powerful ceramic colorant and it is stable in most systems, it appears in many recipes at 1% or lower. Like copper, it melts very actively in oxidation. If it is mixed into a fluid frit base in high enough a percentage, it will completely crystallize during cooling. Cobalt is also useful as a body and slip stain (see the oxide CoO oxide for more information). However, cobalt materials are very expensive, this severely limits its practical use in many things.

Understanding exactly what cobalt oxide powder is and how it decomposes is complicated. Suppliers stock a product normally referred to as 71% Cobalt (or similar), this refers to the amount of Co metal. This product of commerce is theoretically Co3O4 (although possibly somewhere between CoO and Co2O4). Pure CoO, however, would be 78.6% cobalt metal. The difference is thus the extra oxygen in the Co3O4 that is liberated during firing. For this reason, the chemistry defined here has a loss on ignition. Additionally, raw cobalt oxide powder does not decompose to actual CoO during glaze melting unless the kiln is fired in reduction. These complications will simply necessitate a small adjustment in the percentage to adjust color when needed.