Treatment of Ferrosilicon with Boron-Containing Fluxes to Reduce Aluminum Content

In this work, a complete thermodynamic modeling of the ferrosilicon treatment process with borate fluxes was performed. It was found that in this case, aluminum is removed from ferrosilicon and alloying with boron occurs. The presence of boron in the metal is provided by FeB, Fe5SiB2 and TiB2. 86% of the loaded boron is extracted into the metal. Laboratory experiments were conducted to obtain ferrosilicon with a low aluminum content in a Tamman resistance furnace. The possibility of practical production of ferroalloy using Kazakhstan borate ore as a flux was proven. The average chemical composition of the resulting ferrosilicon (wt. %): 63,6 Fe, 31,89 Si, 3,41 B, 0,51 Ti, 0,31 Cu, 0,26 Al.