Crystal Transformation of Sericite during Fluidized Roasting: A Study Combining Experiment and Simulation

Fluidized roasting is an efficient method to promote vanadium extraction from V-bearing mica in shale. In this study, the transformation behavior of sericite during fluidized was explored by combining experimental detections and density functional theory (DFT) calculations. TG-MS, XRD, FTIR, SEM-EDS were used investigate characteristics roasted samples. The crystal parameters calculated with Materials Studio. results showed that dehydroxylation main reaction roasting, which occurred between 650 °C 960 °C. After being at 900 for 2 h, hydroxyls completely removed. calculation show ?OH removed metal ions O-layer, turned hexa-coordinate V3+, Al3+, Fe3+ into pentacoordinate. Through electronic rearrangement, bond lengths two connected shortened 0.18~0.20 nm 0.17 nm. However, some chemical bonds grown, indicates they are weaker easier transform. addition, twisted six-membered rings formed obvious angle changes on (0 0 1) surface. Furthermore, Mulliken’s overlap populations V-O, Al-O, Fe-O decreased. Therefore, a determining factor destruction crystals also promotes release