Considering the decreasing reserves of high-grade iron ores, the utilization of low-grade iron ores is of great significance to the steel industry; however, improving iron recovery from low-grade iron ores is challenging. In this study, to improve iron recovery from low-grade iron ores, preconcentration was performed, followed by two separation processes, namely, reverse flotation (RF) and suspension magnetization roasting-magnetic separation (SRM), which were selected for comparing their effects on Fe grade and Fe recovery. The results showed that the iron grade and iron recovery rate of the concentrate obtained under the optimized RF conditions were 64.76% and 64.83%, respectively, and those under the optimized SRM conditions (500 °C roasting temperature, 20 min roasting time, 20% CO concentration, and 200 mL/min gas flow rate) were 69.60% and 99.18%, respectively. The analysis of the roasted products obtained by suspension magnetization roasting through X-ray diffraction, Mössbauer spectroscopy, and X-ray photoelectron spectroscopy and by using a vibrating sample magnetometer showed that most hematite in the roasting feed was reduced to magnetite, which significantly enhanced the saturation magnetization of the roasted product and effectively facilitated the subsequent magnetic separation. Multiple cracks were formed in the roasted product, unlike the roasting feed (which had a smooth surface); the crack formation resulted in the acceleration of the magnetization reaction in the iron ore.

考虑到高品位铁矿石储量不断减少，利用低品位铁矿石对钢铁行业意义重大；然而，提高低品位铁矿石的铁回收率具有挑战性。在本研究中，为了提高低品位铁矿石的铁回收率，先进行预富集，然后进行两种分离工艺，即反浮选 (RF) 和悬浮磁化焙烧磁选 (SRM)，并选择它们来比较它们的效果关于铁品位和铁回收率。结果表明，优化RF条件下得到的精矿铁品位和铁回收率分别为64.76%和64.83%，优化SRM条件下（焙烧温度500 ℃，焙烧时间20 min，20%） CO 浓度和 200 mL/min 气体流速）为 69。分别为 60% 和 99.18%。通过 X 射线衍射、穆斯堡尔谱和 X 射线光电子能谱和振动样品磁强计对悬浮磁化焙烧得到的焙烧产品进行分析表明，焙烧原料中的大部分赤铁矿被还原为磁铁矿，显着提高了焙烧产物的饱和磁化强度，有效地促进了后续的磁选。与烘烤饲料（表面光滑）不同，烘烤后的产品形成了多处裂缝；裂纹的形成导致铁矿石中磁化反应的加速。X射线光电子能谱和振动样品磁强计表明，焙烧原料中的赤铁矿大部分还原为磁铁矿，显着提高了焙烧产品的饱和磁化强度，有效促进了后续磁选。与烘烤饲料（表面光滑）不同，烘烤后的产品形成了多处裂缝；裂纹的形成导致铁矿石中磁化反应的加速。X射线光电子能谱和振动样品磁强计表明，焙烧原料中的赤铁矿大部分还原为磁铁矿，显着提高了焙烧产品的饱和磁化强度，有效促进了后续磁选。与烘烤饲料（表面光滑）不同，烘烤后的产品形成了多处裂缝；裂纹的形成导致铁矿石中磁化反应的加速。不像烘烤饲料（表面光滑）；裂纹的形成导致铁矿石中磁化反应的加速。不像烘烤饲料（表面光滑）；裂纹的形成导致铁矿石中磁化反应的加速。