The Influence of Water Vapour on the Fuming Rate in a Ferromanganese System

摘要

During the casting of ferromanganese alloys, a considerable amount of dark fumes, consisting primarily of manganese oxides, are generated when the Mn vapour oxidises in the atmosphere. Previous studies indicate that these fumes can be reduced by increasing the humidity above the melt. However, the reduction mechanism is not fully understood. In an attempt to understand the reduction mechanism, the influence of a humidity change on the fuming rate was studied. Laboratory scale experiments were conducted where an impinging jet blew air with a varying humidity onto the melt where dust was captured to determine relative mass fluxes. When the wet air experiments' fume fluxes were compared to the dry air experiment, it was found that the increase in humidity resulted in a significant fume reduction (between 33 and 79%), confirming industrial observations. Dust composition from the experiments as well as dust reduction mechanisms are presented and discussed.