AI Jun , LU Xilong , WANG Weixing , CHEN Yunxia , CAO Chun'e
(Jingdezhen Ceramic Institute, Jingdezhen Jiangxi 333000, China)
Abstract: CoAl2O4 spinel -type cobalt blue pigments were prepared by the citric acid chelating method, using citric acid aschelating agent and Co(NO3)2·6H2O and Al(NO3)3·9H2O as the precursors. The influence of different calcining temperatures and different ratios of Co to Al on the coloration of pigments was systematically investigated. TG/DTA was employed to investigate the reaction process of chelation. The samples were characterized by colorimetric measurement, XRD and FTIR techniques. The results indicate that CoAl2O4 spinel-type cobalt blue pigments with good coloration were prepared at aminimum temperature of 700℃ via citric acid chelating precursor method. The spinel phase were obtained after thermal treatment at 450℃, and still appeared black. The color became more intense as the temperature rose. The sample with the
Co/Al ratio of 1∶3 and the soaking time of 2h had the best coloration.
Key words: CoAl2O4; citric acid; chelating precursors; spinel type pigments