Preparation of fusible pellets from fine-grained iron ore concentrates
WEN Bao-liang1, ZHANG Xiao-ping1,2, LI Jia-xin1, WU Hong-liang1,2, YANG Jia-long1
1. School of Metallurgical Engineering, Anhui University of Technology, Maanshan 243032, Anhui, China; 2. Technical Center, Maanshan Iron and Steel Co., Ltd., Maanshan 243003, Anhui, China
Abstract：The current research on the pelletization of fine-grained iron ore concentrate mainly focuses on the production of acidic pellets. To further improve the industrial application of fine-grained iron ore concentrate and to relieve the resource pressure of pellet production, the preparation of fusible pellets using fine-grained iron ore concentrate under different methods was investigated. The results show that: the fusible pellets prepared from fine-grained iron ore concentrate with 0.8-1.2 alkalinity and bentonite with limestone have better pellet quality, with a drop strength of 7.3 times/0.5 m and compressive strength of 16 N/pc, while the pellets prepared with slaked lime as binder and flux require an alkalinity greater than 1.0 to meet the production standard. Based on the model fitting results, the molten pellets with bentonite and limestone added to the fine-grained iron ore concentrate had a longer drying completion time than the molten pellets with slaked lime only, which were 360 s and 270 s. Based on the model fitting results, the molten pellets with slaked lime only had a higher water transfer and diffusion coefficient with Bi value less than 0.1, and the temperature distribution inside the raw pellets tended to be uneven during the drying process. Whether bentonite or slaked lime is used as binder for the production of fine-grained concentrate fusible pellets, a higher roasting temperature is required to promote the formation of large continuous crystals between hematite ores, and the strength of bentonite pellets with limestone is 3 656 N/pc and slaked lime pellets is 3 398 N/pc at a roasting temperature of 1 250 ℃. At 0.8-1.2 alkalinity, compared to the addition of bentonite and limestone, the addition of slaked lime only The fine-grained iron ore concentrate fusible pellets with slaked lime will slightly reduce the pellet reduction, but can improve the reduction swelling and reduction pulverization of the pellets, and the fine-grained iron ore concentrate fusible pellets prepared by both methods have good metallurgical properties.
温宝良, 张晓萍, 李家新, 吴宏亮, 杨佳龙. 细粒级铁精矿制备熔剂性球团[J]. 钢铁, 2023, 58(10): 23-33.
WEN Bao-liang, ZHANG Xiao-ping, LI Jia-xin, WU Hong-liang, YANG Jia-long. Preparation of fusible pellets from fine-grained iron ore concentrates[J]. Iron and Steel, 2023, 58(10): 23-33.
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2023, Vol. 58 
