Selective enrichment and extraction of well-catalyzed perovskites on melting-microwave heating process from blast furnace slag

Abstract

Titanium-bearing blast furnace slag (TBFS) is an important secondary resource, accounting for half of the world's titanium resource reserves, but its utilization ratio is less than 3%. Making full use of the difference in microwave absorption ability, density and melting point of titanium-bearing components with others in TBFS, this research pioneered a new technology of melt pretreatment-microwave selective heating process to extraction of well-catalyzed CaTiO3 derived from low-grade titanium-bearing resource. It is found that melt pretreatment (1300 °C for 1 h) promoted the transition of titanium from low-valent to high-valent, which is beneficial to enhance the difference of microwave absorption ability among components in TBFS. Furthermore, microwave heating induced the extrication of CaTiO3 from silicate to form crystal-branched structures with special aspect ratio. Meanwhile, microwave effect arose the silicate melt dripping to realize directional migration of CaTiO3. CaTiO3 product (content of 82 wt%) obtained by gravity separation performed well-catalyzed characterization with band gap of 2.25 eV. This study provided the key guidance and feasible route for component extraction derived from titanium-bearing slag.