Desilication kinetics of calcined boron mud in molten sodium hydroxide media

Desilication kinetics of calcined boron mud （CBM） occurring in molten sodium hydroxide media was investigated. The effects of factors such as reaction temperature and NaOH-to-CBM mass ratio on silicon extraction efficiency were studied. The results show that silicon extraction efficiency increases with increasing the reaction time and NaOH-to-CBM mass ratio. There are two stages for the desilication process of the calcined boron mud. The overall desilication process follows the shrinking-core model, and the first and second stages of the process were determined to obey the shrinking-core model for surface chemical reaction and the diffusion through the product layer, respectively. The activation energies of the first and second stages were calculated to be 44.78 kJ/mol and 15.94 kJ/mol, respectively.