Introduction of green pigment for ceramics
In turquoise or green spinel systems, adding chromium oxide to replace part of alumina and adding zinc oxide to replace part of cobalt oxide will change the shade of pigment tone.The green and blue replacement method is to add vanadium zirconium blue.These pigments are less obvious than cobalt pigments and tend to be greenish blue.But vanadium-zirconium blue is often used to prepare harmonic color in zirconium pigments. It has excellent compatibility and stability.
Green pigments have traditionally been made from Cr2O3.But this color is not stable. It is susceptible to the influence of ZnO or SnO2 in glazes.Satisfactory results were obtained by adding chromium to make spinel pigment.Zinc chrome spinel and Cr2O3 are similar in color.Cobalt-chromium series blue-green material is a transition color from zinc-chromium color (such as zinc-chromium spinel) to cobalt-aluminum color (such as cobalt-aluminum spinel).People can get a deeper green color by increasing CrO3 and decreasing the amount of cobalt oxide.On the contrary, by reducing chromium oxide and increasing cobalt oxide content, different colors from blue green to blue can be made.
A special type of chrome green is Victoria green.This colour performs a very bright and beautiful green, and is very transparent.But it is also difficult to stabilize the color because it is sensitive to the base glaze.
Chromium oxide is the basis of green pigments.Traditional green materials include only yellow-green Ca-Cr-Si Victoria green. And malachite blue which is a blue-green in the strong blue of the Co-(Zn)-(Al)-Cr (the former is garnet type, the latter is the spinel type) and other few.And Victoria Green has strict requirements on the base glaze.It dissolves in a ZnO glaze and therefore cannot be used in a Zinc glaze.But the new green colors are much more lenient. For example, zirconium, vanadium and vanadium blue (Zr-Si-V) and zirconium, praseodymium and praseodymium yellow (Zr-Si-Pr) or tin, vanadium and vanadium yellow can be prepared to obtain a wide range of green tones.And this series of green materials, in lime-zinc and other Zn0 glaze is the most beautiful color. It can be widely used in lime-zinc-lead glaze.These colors have a wide range of use and are of great economic and practical value.
The green series includes traditional garnet chromium green (also known as Victoria green, daffodil green) and spinel peacock green, and zirconite praseodymium green (also known as apple green). But praseodymium green material is usually made by vanadium zirconium blue and praseodymium yellow according to proportion of the material. Green general is not preparation separately .
