Abstrakt:
The study deals with the preparation of the inorganic pigments of general formula
CaSn0.855Cr0.045Ln0.1SiO5±δ, belonging to the group of the malayaites, where Ln =
La, Ce, Pr, Nd, Sm, Eu and Gd (LMREE). The malayaite samples were prepared
in powdered form by the solid state reaction. As initial components were used the
following basic raw materials: calcium carbonate, tin oxide, chromium oxide,
silicon oxide, and oxide of the respective lanthanoid serving as the dopant. The
reaction mixtures were homogenised and ground in the planetary mill for five
hours. After mechanoactivation, they were calcinated at the temperatures from
1200 °C to 1450 °C in the electric furnace for four h. All the prepared pigments
were applied / converted into a ceramic glaze P07410 and very interesting
colours obtained: brown pink, deep burgundy, and red carmina shades.. The
colour characteristics were described by CIE L*a*b* system (1976). From the particle size distribution, it is evident that all three parameteres, d(0.1) μm, d(0.5)
μm, and d(0.9) μm have increased with temperature. Finally, as confirmed
experimentally, the mechanoactivation has led to very thin granules, increasing
the brightness (L*).
