Aggregation Behavior of Desulfurization Flux in Hot Metal Desulfurization with Mechanical Stirring

Abstract

The aggregation behavior of desulfurization flux in hot metal desulfurization with mechanical stirring was investigated by small-scale hot metal experiments. Desulfurization flux added from the top aggregated in the hot metal during stirring, reducing the interfacial area between the flux and hot metal, which had a large effect on the desulfurization rate. The size of aggregated slag can be estimated using an aggregation model based on granulation theory. The obtained aggregation rate constant, k_a, is 4.5–40.9×10^–11 (m³/s). The interfacial area between flux and hot metal can be estimated using the aggregation model, which can also estimate desulfurization behaviors under various conditions. The obtained slag size after desulfurization agreed with the calculated slag size in the equilibrium state, which is highly dependent on stirring conditions. The aggregation rate in commercial-scale (270 ton) desulfurization is larger than that in small-scale experiments due to the difference of their stirring energies.