Direct extraction of perovskite CaTiO3 via efficient dissociation of silicates from synthetic Ti-bearing blast furnace slag

• Published in: Hydrometallurgy 2017-01, Vol.167, p.8-15
• Main Authors: Wu, Min-Zhi, Lü, Hui-Hong, Liu, Min-Chao, Zhang, Zheng-Li, Wu, Xing-Rong, Liu, Wei-Ming, Wang, Ping, Li, Liao-Sha
• Format: Article
• Language: English
• Subjects: Direct extraction of perovskite; Efficient dissociation; Reconstruction of mineral phases; Silicon containing components; Ti-bearing blast furnace slag
• ISSN: 0304-386X; 1879-1158
• DOI: 10.1016/j.hydromet.2016.10.026

A new method of extract perovskite CaTiO3 from synthetic Ti-bearing blast furnace slag (Ti-slag) is proposed. After thermal modification of Ti-slag with 30% NaNO3, the silicon containing components has been reconstructed, which can be more easily dissolved in the leaching process. The effect of composition, morphology and mineral phases of the silicon containing components on the direct migration into acid soluble silicates in minerals and solutions is illuminated. Furthermore, the leaching kinetics of the modified slag in a 10% hydrochloric acid solution was described by the shrinking core model (SCM). The apparent activation energy of the dissociation of “Si” was calculated to be about 17.23kJ/mol, which indicates that the perovskite extraction is controlled both by interface transfer and solid product layer diffusion. The content of perovskite in the residue is 88.3% with 1.4% SiO2. The results of this study can provide an important method for direct extraction perovskite CaTiO3 in the Ti-slag and also establish a new strategy for resources of complex high silicate minerals. •A novel method for direct extraction of perovskite from Ti-slag is established.•There is 88.3% perovskite with 1.4% SiO2 in residue using the present method.•Extraction of perovskite was controlled by interface transfer and solid diffusion.•The strategy can be extended for resources of complex high silicate minerals.