Cleaner preparation of high blueness cobalt blue composite pigments using dolomite and kaolin tailing sand

Cleaner and value-added resourceful utilization of the tailings or natural mineral resources has gained increasingly attention under the advanced concept of green and sustainable development. To develop an environmental-friendly preparation process for cobalt blue pigments with high chroma and low cobalt consumption, a dolomite-induced mechanochemical technology was developed for fabrication of cobalt blue composite pigments with controllable high blue intensity in the presence of kaolin tailing sand without using and discharging waste liquids. It revealed that the excellent color performance (L* = 37.63, a* = 10.68, b* = −54.87, C* = 55.91) benefitted from the Ca/Mg species and the lamellar morphology of dolomite by the mechanical force, which could facilely adjust the color performance and in-situ load pigment nanoparticles, respectively. The composite pigments presented a flaky morphology decorated with about 10 nm of nanoparticles, and consisted of calcium aluminate, anorthite, quartz and spinel magnesium cobalt aluminates. It is worth mentioning that the as-prepared composite pigments exhibited excellent environmental stability and good application performance as painting ink on rice paper. Therefore, this novel and cleaner technology is expected to produce high-performance cobalt blue pigments with lower cobalt consumption, as well as simultaneously realize the resource utilization of kaolin tailing sand and dolomite.