Sol-Gel Processing of Ceramic Pigments, Part 3: Synthesis of Uvarovite

Ceramic pigment of the garnet type "Victoria green" was produced industrially using the classic procedure: high temperature synthesis, long reaction time and presence of mineralizer. The object of this investigation was the synthesis of garnet by the sol-gel method. Due to the high homogenity of the initial reaction mixture with nano size particles, this method provided a possibility of uvarovite synthesis at lower temperature. For garnet synthesis by the sol-gel and hydrothermal method, colloidal silica, ammonium chromate and calcium chloride were used as starting reactants, while commercial products such as CaCO 3 , Cr 2 O 3 and SiO 2 were used for the ceramic method. The phases present in synthetized pigments were detected by X-ray. It was confirmed that the sol-gel method enables the synthesis of garnet, Ca 3 Cr 2 (SiO 4 ) 3 to be performed at a lower temperature than that required for the ceramic method. The chromatic characteristics of the pigment were tested in industrially glazed ceramic tiles at the Zorka-Non-metals Plant in Sabac, Serbia.