Zhang Kai, Chen Xiu Li, Guo Wen Chao, Luo Hui Juan, Gong Zhi Jun, Li Bao Wei, Wu Wen Fei
School of Energy & Environment, Inner Mongolia University of Science & Technology, Baotou, Inner Mongolia Autonomous Region, China.
Key Laboratory of Integrated Exploration of Bayun Obo Multi-Metal Resources, Baotou, Inner Mongolia Autonomous Region, China.
PLoS One. 2017 Oct 17;12(10):e0186274. doi: 10.1371/journal.pone.0186274. eCollection 2017.
Biomass was used as reducing agent to roast the Baotou low-grade limonite in a high temperature vacuum atmosphere furnace. The effect of calcination temperature, time and ratio of reducing agent on the magnetic properties of calcined ore was studied by VSM. The phase and microstructure changes of limonite before and after calcination were analyzed by XRD and SEM. The results show that in the roasting process the phase transition process of the ferrous material in limonite is first dehydrated at high temperature to formα-Fe2O3, and then it is converted into Fe3O4 by the reduction of biomass. With the increase of calcination temperature, the magnetic properties of the calcined ore first increase and then decrease. When the temperature is higher than 650°C, Fe3O4 will become Fe2SiO4, resulting in reduced the magnetic material in calcined ore and the magnetic weakened. The best magnetization effect was obtained when the roasting temperature is 550°C, the percentage of biomass was 15% and the roasting time was 30min. The saturation magnetization can reach 60.13emu·g-1, the recovery of iron was 72% and the grade of iron was 58%.
以生物质为还原剂，在高温真空气氛炉中焙烧包头低品位褐铁矿。采用振动样品磁强计（VSM）研究了焙烧温度、时间和还原剂比例对焙烧矿磁性的影响。通过X射线衍射仪（XRD）和扫描电子显微镜（SEM）分析了褐铁矿焙烧前后的物相和微观结构变化。结果表明，在焙烧过程中，褐铁矿中铁质材料的相变过程是先在高温下脱水形成α-Fe2O3，然后通过生物质的还原作用转化为Fe3O4。随着焙烧温度的升高，焙烧矿的磁性先增大后减小。当温度高于650℃时，Fe3O4会变成Fe2SiO4，导致焙烧矿中的磁性物质减少，磁性减弱。焙烧温度为550℃、生物质用量为15%、焙烧时间为30min时，磁化效果最佳。饱和磁化强度可达60.13emu·g-1，铁回收率为72%，铁品位为58%。
