Research status of new technology for magnetization roasting and reduction of refractory iron ore in China

Abstract

Iron ore is the raw material for smelting steel, and the steel smelting industry occupies an important position in the development of the national economy. In China, the reserves of iron ore are large, but the iron ore has the characteristics of low grade and sorting is difficult, which limits the application of domestic iron ore. In order to meet the demand for raw materials in China’s steel industry, China has long imported iron ore from other countries. Therefore, China’s strong dependence on imported iron ore and the low utilization rate of domestic iron ore need to be solved urgently. Studies have shown that magnetic roasting reduction technology is an effective method to reduce the iron ore phase in iron ore and improve the magnetic properties of iron ore. And magnetic roasting reduction technology can optimize the magnetic separation selectivity of iron ore. Through the magnetic separation of the iron ore after magnetization roasting, high-grade fine iron ore can be obtained. The magnetization roasting-magnetic separation process can effectively improve the enrichment and separation efficiency of domestic ores and improve the utilization rate of domestic ores. In this paper, the reduction effect of siderite, hematite and limonite as the main iron ore phase after carbon-based roasting reduction technology or hydrogen-based roasting reduction technology and the research status of the quality of concentrate iron ore after magnetic separation are reviewed, and the best reduction system of different ore reduction roasting process is put forward. The transformation law and reaction mechanism of each mineral phase in the process of carbon-based roasting reduction and hydrogen-based roasting reduction of ores with different iron ore phases are introduced. The future development direction of magnetic roasting reduction technology is analyzed, which has guiding significance for the selection of magnetic roasting reduction technology for other refractory iron ores and the development of subsequent mineral enrichment and separation technology.