CARBOTHERMIC REDUCTION OF BORON-OXIDE .1. KINETICS AND REACTION-MECHANISMS

The mechanism of the reaction B2O3+3[C](Fe) = 3CO+2[B](Fe) has been in vestigated by studying the kinetics of the reaction. Boron oxide pelle ts were dropped on iron melts containing graphite and the gas evolved was monitored as a function of time until the reaction was completed. It was found that the reaction was controlled by: (i) the dissociation reaction of B2O3 below 1500 degrees C; (ii) the diffusion rate of car bon above 1500 degrees C. The principal reaction mechanism occurred se quentially by: (i) the dissociation of B2O3; (ii) the diffusion of oxy gen atoms into the melt; (iii) the reaction between the dissolved carb on with oxygen. (C) Munksgaard, 1997.