Results in Engineering (Jun 2025)
Industrial-scale trials for the production of oxidized Panzhihua ilmenite concentrate pellets followed by smelting in an EAF for titania slag production
Abstract
Electric arc furnace (EAF) smelting of ilmenite concentrate is the primary method for upgrading titania, producing high-quality titania slag for titanium dioxide and sponge titanium production, while also enabling the recovery of hot metal for steelmaking. However, deeper mining of vanadium-titanium magnetite results in finer mineral dissemination and requires finer grinding, leading to ilmenite concentrates that pose several challenges for EAF smelting, including high energy consumption, low recovery rates, poor hot metal quality, and excessive SO2 emissions. To address these challenges, this study tested the industrial-scale production and smelting of oxidized Panzhihua ilmenite concentrate pellets in a 25.5 MVA EAF. The results showed that pellets could be produced with a 0 % cracking rate, compressive strength of 698 N, and a tumbler index of 83 %. Continuous feeding of these pellets into the EAF stabilized the process, prevented foaming slag, and improved reaction control compared to batch feeding of raw ilmenite concentrate fine powder. Optimized conditions reduced power consumption per ton of titania slag from 2546.51 to 2218.87 kWh·t⁻¹ and shortened smelting time from 7.23 to 7 h. The carbon content in hot metal increased from 1.16 % to 2.5 %, while sulfur content decreased from 0.32 % to 0.11 %. Tapping temperature was reduced from 1480 °C to 1430 °C, and SO2 emissions were significantly lowered. The industrial performance of smelting oxidized ilmenite concentrate pellets was also evaluated against raw ilmenite concentrate fine powder in an electric furnace. This study confirms that industrial-scale production and smelting of oxidized Panzhihua ilmenite concentrate pellets in an EAF is both technically feasible and environmentally beneficial for titania slag production.
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