鲕状赤铁矿悬浮焙烧的磁性研究

针对鄂西某鲕状赤铁矿进行悬浮焙烧研究,并采用振动样品磁强计、X射线衍射分析仪、穆斯堡尔谱仪分析还原温度、还原时间、氧化温度、颗粒粒度对焙烧物料磁性和物相组成的影响规律.结果表明:铁矿石经悬浮焙烧后磁性明显增强,且焙烧物料磁性与强磁性铁矿物的含量呈正比.当还原温度为550~650℃时,还原物料的磁化强度和比磁化率随还原温度的升高而升高,超过700℃后则随之降低.延长还原时间可提高还原物料的磁化强度和比磁化率.焙烧物料中γ-Fe2O3含量随氧化温度升高而增加,在氧化温度为350℃时物料中γ-Fe2O3的含量达到最大值.当焙烧物料颗粒粒度小于15μm时,颗粒的磁化强度和比磁化率随之降低,而剩磁和矫顽力则随之增加.

Research on Magnetic Properties of Oolitic Hematite Roasted by Suspension Roasting Furnace

Suspension roasting test result of oolitic hematite from west part of Hubei province was investigated. The effects of reduction temperature， reduction time， oxidation temperature， particle size on the magnetic properties and phase composition of reduced iron ore were investigated by using vibrating sample magnetometer， X-ray diffraction， Mssbauer spectrometer. The results show that magnetic properties of iron ore enhanced obviously after suspension roasting and directly proportional to the content of strong magnetic iron minerals. Both the magnetization intensity and magnetic susceptibility of reduced ore increased with increase of reduction temperature when reduction temperature range from 550℃ to 650℃. However， when reduction temperature rose to over 700℃， both the magnetization intensity and magnetic susceptibility decreased accordingly. The magnetization intensity and magnetic susceptibility of reduced ore increased with reduction time extending. The content of γ-Fe₂O₃ in roasted ore increased with the increase of oxidation temperature and reached the maximum value when oxidation temperature was at 350℃. When particle size is smaller than 15μm， the magnetization intensity and magnetic susceptibility of particle decreased with the decrease of particle size， while remenance and corecivity of particle increased correspondingly.