CaCO3-assisted mechanochemical synthesis of low-cost and high-chroma cobalt blue composite pigments using kaolin tailing sand for ceramic coloring

•Mechanochemical method was developed to prepare CoAl2O4 composite pigments.•Low-cost and high chroma CoAl2O4 composite pigments were prepared using kaolin tailing sand.•CaCO3 was acted as green precipitant for co-precipitation of hydrated metal salts.•Incorporation of kaolin tailing sand obviously enhanced the color properties of CoAl2O4.•CoAl2O4 composite pigments could be served as promising ceramic pigments.