Abstract
The solid phase method was used to synthesize spinel CoAl2O4 and willemite (Co, Zn) 2SiO4 cobalt blue materials, and their color rendering and acid resistance were compared. The SiO2 and MgO were introduced to modify the Co2O3-Al2O3 system and the finely ground CoAl2O4 was taken as crystal nucleus to investigate its effect on the color rendering of the pigment and acid resistance. The on-glaze cobalt blue pigment with bright color rendering, high color saturation and good acid resistance was developed. The solid phase method was used to synthesize willemite cobalt blue material and then the lead-free flux with strong acid resistance was selected and mixed with the pigment in a certain proportion. The cobalt blue pigment was obtained by baking at a certain temperature. Through the single factor test and orthogonal test, the flux formula was optimized and the secret cobalt blue pigment with bright color rendering and good acid resistance was obtained. The results show that the spinel structure is superior to willemite structure in terms of acid resistance and the introduction of the finely ground CoAl2O4 crystal nucleus can improve the color rendering effect and acid resistance of the spinel cobalt blue material. XRD analysis shows that the main crystal phase of the optimal formula pigment is CoAl2O4, but there are SiO2 residues.
