Metal and Slag Extraction from Different Zones of a Submerged Arc Furnace with Non-uniform Porous Bed Using CFD

A submerged arc furnace (SAF) is generally used in the production of ferroalloys (referred to as metal in this study). Viable production of ferroalloys requires a consistent tapping process where metal and slag are extracted from the furnace. The tapping flow rates depend on various in-furnace conditions such as the height of the metal and slag column, presence of a porous coke bed (particle bed), crater pressure, and the physical properties of the fluids. In order to understand the difference in drainage of metals and slags produced in different zones of the furnace, a computational fluid dynamics (CFD) study is performed. Variations in the tapping of metal and slag from the different zones would lead to accumulation in the furnace, thus reducing its efficiency. A comparison between the tapping rates for the metal produced in the front or the back zone of the furnace is performed for a uniformly distributed coke bed and a coke-free bottom region. The tapping rates of slag produced in different zones of the furnace for a uniformly distributed particle bed are also compared. The results showed that the furnace reached a quasi-steady state quicker for the coke-free bottom region compared to the uniformly distributed particle bed, whereas the tapped metal comes equally from all zones of the furnace. It took longer for the simulation to reach a quasi-steady state for extraction of slag produced in different zones due to higher initial volume of slag. At the quasi-steady state, the slag was tapped equally from all zones of the furnace.