CHEN Yibing¹, XIA Guanghua², XU Yuxin³, ZHANG Xiaolin⁴, TAN Xunyan⁵

(School of Material Science and Engineering, Jingdezhen Ceramic Institute, Jingdezhen 333403, Jiangxi, China)

Abstract: Beihai kaolin was used as a raw material, thiourea dioxide as a reducing agent. The influence of ratio of reactant, pH value and dose of coordination complex on the reduction potential of thiourea dioxide was investigated. The samples were characterized by means of XRD and SEM. The results showed that: when the self-made cerium chloride, PHBA and 1,10-Phenanthroline monohydrate were mixed to the molar ratio of 1:1:1, the pH value was 9 in the reaction process, the dose of coordination complex was 3wt.% of thiourea dioxide,the reduction potential of thiourea dioxide was -786 mv, improved by -335 mv compared with the thiourea dioxide without excitation. The activated TD has an obvious effect on kaolin reduction and iron removing. The calcined whiteness of the bleached kaolin was 88.7%, which was 4.7% higher than that of the untreated kaolin sample, whose calcined whiteness was 84%.

Key words:rare earth complexes; kaolin; thiourea dioxide; iron removal; calcined whiteness