Muller, JacquesZietsman, Johannes HendrikPistorius, Petrus Christiaan2015-08-212015-08-212015-12Muller, J, Zietsman, JH & Pistorius, PC 2015, 'Modeling of manganese ferroalloy slag properties and flow during tapping', Metallurgical and Materials Transactions B: Process Metallurgy and Materials Processing Science, vol. 46, no. 6, pp. 2639-2651.1073-5615 (print)1543-1916 (online)10.1007/s11663-015-0426-7http://hdl.handle.net/2263/49429Stable operation of submerged-arc furnaces producing high-carbon ferromanganese (HCFeMn) and silicomanganese (SiMn) requires tapping of consistent amounts of liquid slag and metal. Minimal effort to initiate and sustain tapping at reasonable rates is desired, accommodating fluctuations in especially slag chemical composition and temperature. An analytical model is presented that estimates the tapping rate of the liquid slag-metal mixture as a function of taphole dimensions, coke bed particulate properties, and slag and metal physicochemical properties with dependencies on chemical composition and temperature. This model may be used to evaluate the sensitivity to fluctuations in these parameters, and to determine the influence of converting between HCFeMn and SiMn production. The model was applied to typical HCFeMn and SiMn process conditions, using modelled slag viscosities and densities. Tapping flow rates estimated were comparable to operational data and found to be dependent mostly on slag viscosity. Slag viscosities were generally lower for typical SiMn slags due to the higher temperature used for calculating viscosity. It was predicted that flow through the taphole would mostly develop into laminar flow, with the pressure drop predominantly over the coke bed. Flow rates were found to be more dependent on the taphole diameter than on the taphole length.en© The Minerals, Metals & Materials Society and ASM International 2015. The original publication is available at : http://link.springer.com/journal/11663.TapholeHigh-carbon ferromanganeseSilicomanganesePhysicochemical propertiesEngineering, built environment and information technology articles SDG-07SDG-07: Affordable and clean energyEngineering, built environment and information technology articles SDG-08SDG-08: Decent work and economic growthEngineering, built environment and information technology articles SDG-09SDG-09: Industry, innovation and infrastructureEngineering, built environment and information technology articles SDG-12SDG-12: Responsible consumption and productionEngineering, built environment and information technology articles SDG-13SDG-13: Climate actionPostprint Article