An innovation for strengthen iron extraction from phosphorus-bearing refractory iron ore via suspension magnetization roasting and flotation

High-phosphorus refractory iron ore was usually stacked in the mine as an abandoned resource due to a lack of methods for efficient iron extraction and dephosphorization reduction. In this work, an innovation which includes processes of grinding, suspension magnetization roasting, and flotation was proposed for efficient utilizing the High-phosphorus refractory iron ore. After being roasted at the optimal conditions that roasting temperature of 560 degrees C, CO concentration of 30 %, and roasting time of 20 min, a magnetic separation concentrate with a Fe grade of 57.95 % and P content of 0.69 % obtained. The flotation was used to further remove phosphorus. After the flotation process, the Fe grade of the concentrate increases to 60.12 % while the P content decreases to 0.29 %. Analysis results show that the iron phase route was Fe2O3 center dot nH2O -. Fe2O3 -. Fe3O4. Many pores and cracks were generated on the surface of iron mineral particles and improved the reducing gas adsorption in suspension magnetization roasting. Larger cracks promoted adsorption of flotation reagents and the separation between iron mineral and P-bearing mineral. Therefore, this innovation contributes to improving the magnetism of weakly magnetic iron ore and enhances the separation effect of Fe extraction and dephosphorization. It has good industrial application potential. (c) 2024 Published by Elsevier B.V. on behalf of The Society of Powder Technology Japan. All rights reserved.