1992 Volume 78 Issue 2 Pages 223-230
The rate of smelting reduction of chromite ore in (CaO)-(SiO2)-(Al2O3)-(MgO) slag by the dissolved carbon in liquid iron held in graphite crucible has been studied in order to investigate the reduction mechanism at the interface between metal and slag. The behavior of slag foaming during the reduction of the ore was also examined.
The rate constant at the interface between metal and slag was in proportion to -0.82 power of slag viscosity and the apparent activation energies were 167 and 249 kJ/mol. Therefore it was estimated from these that the rate at this interface was controlled by mass transport of (CrO) in slag. The slag foaming height was kept constant during the time when the rate was expressed by the zeroth-order rate equation. The foam life decreased with an increase in both (MgO) content and (CaO)/(SiO2) ratio, whereas a relation between the foam life and the content of (Al2O3) was obscure. The foam life obtained was strongly affected by slag viscosity.
