Recent Advances in Magnetization Roasting of Refractory Iron Ores: A Technological Review in the Past Decade

Improving utilization efficiency of refractory iron ore resources is a common theme for the sustainable development of the world’s steel and iron industry. Magnetization roasting is considered as an effective and typical method for the beneficiation of refractory iron ores. After magnetization roasting, the weakly magnetic iron minerals, including hematite, limonite and siderite, are selectively reduced or oxidized to ferromagnetic magnetite, which is relatively easier to enrich by magnetic separation after liberation pretreatments. The primary magnetization roasting methods include shaft furnace roasting, rotary kiln roasting, fluidized bed roasting, and microwave assisted roasting. This review highlights the developments in magnetization roasting of difficult to treat iron ores, including shaft furnace roasting, rotary kiln roasting, fluidized bed roasting, and microwave assisted roasting in the past decade. Fluidized bed roasting and microwave assisted roasting are considered as the most effective and promising methods, which is essential to be reviewed. Meanwhile, the effective and future magnetization roasting technologies are recommended throughout this review.