Synthesis of Cr-doped sphene ceramic pigments by spray drying

Ceramic pigments with Cr-doped sphene structure (CaSn1-xCrxSiO5, CaTi1-xCrxSiO5) were synthesized by both spray drying an aqueous solution of precursor salts plus further calcining the resulting powders and conventional ceramic method. The thermal evolution of products was studied by X-Ray Powder Diffraction (XRPD). The powder morphology and chemical composition were analyzed by SEM-EDX. The color efficiency of pigments was evaluated by colorimetric analysis (CIELab system). Results showed that the spray drying process decreased the maximum firing temperature and increased the color efficiency of Cr-doped sphene pigments therefore enhancing a higher reactivity of powders compared with the solid state process.