Influence of slag and foam characteristics on reduction of FeO-containing slags by solid carbon

Abstract

The present study reports experimental results on the reduction of FeO in molten CaO-SiO 2 -Al 2 O 3 -MgO-FeO slags by solid carbon in an extended-arc plasma reactor. The reduction reaction was found to be controlled by mass transport of FeO in liquid slag. The CO gas generated stirs the bath to establish a convective mass transport system. CO also causes foaming. An analysis using dimensionless numbers provides correlations between the rate constant, k, as well as the foaming index, ⌺, with some properties of the slag such as viscosity, surface tension, and density. A correlation between k and ⌺ is also developed using these parameters for slag characteristics.

The Dynamic Interfacial Oxygen Potential Between Iron-Carbon Droplets and Oxidizing Slag

“…The k FeO in these cases were also listed in Table AIV, but have not been brought into this discussion. It is worth noting that other workers [22,24] have successfully correlated k FeO with the rate of CO bubble generation to justify the effect of FeO content on k FeO .…”

“…Therefore, we have compared the k FeO data for droplets with 0.014 and 0.021 wt pctS in current study, i.e., those for which the slag had a high liquid fraction with cases from Shibata et al and Monaghan et al containing high total iron oxide (>29 wt pct) as shown in Figure 5(b). By studying reduction of iron oxide in FeO-rich slag, most investigators [16][17][18][19][20][21][22][23][24] proposed that the reaction was first order with respect to FeO concentration in the bulk slag, and was most likely controlled by FeO mass transfer in the slag. If this is the case, the apparent rate constant can be converted to a mass transfer coefficient for FeO in the slag as done by Woolley and Pal.…”

In-Situ Observation of Fe0.94O Reduction at High Temperature with the Use of Optical Microscopy

“…Reduction mechanisms of iron oxide in the slag system have been studied extensively. [8][9][10][11][12][13] Oxygen within the air blown to the furnace also forms CO by reacting with carbon in the cokes.…”

Kinetics of CO-CO2 reaction with CaO-SiO2-FeOx melts

“…Such models relating slag properties to the mass-transfer coefficient have also been developed by other authors. [25,26,27] …”