Sustainable Valorization of Hot Blast Furnace Slag: Heat‐Mass Transfer Mechanisms and Process Optimization in Mineral Wool Electric Furnace Smelting

This study investigates freeze‐lining (FL) formation and slag mixing in mineral wool electric furnaces (MWEF) to enhance refractory longevity and energy efficiency. A multi‐physics model integrating electromagnetic fields, heat transfer, and melt flow was developed for a three‐phase AC MWEF, incorporating dynamic feeding and tapping operations. The model simulates FL dynamics and mixing characteristics between hot blast furnace slag (HBFS)‐utilized for sensible heat recovery‐and cold‐modifying agents (CMA) at the slag tap‐hole (STH). Validated against field FL thickness measurements (⟨5% error), the model informs sensitivity analysis via Response Surface Methodology (RSM). Results indicate cooling water demand decreases with furnace diameter (FD) but increases with electrode pitch circle diameter (PCD) and melt pool height (MPH). Conversely, STH mixing time correlates negatively with all three parameters. Multi‐objective optimization yielded an optimal configuration: FD = 6500 mm, PCD = 1600 mm, MPH = 1200 mm. This simultaneously minimizes the cooling water energy consumption proportion (CWECP) and ensures rapid component mixing at STH. The framework provides theoretical guidance for energy‐efficient industrial MWEF design.