机械活化闪锌矿的量热研究

Calorimetric study of mechanically activated sphalerite

用Calvet型微量热计对不同条件下机械活化闪锌矿进行了量热实验 ,并对量热前后的活化闪锌矿进行透射电镜 (TEM )、X射线衍射 (XRD)及激光粒度测试。结果表明 :闪锌矿经机械活化后 ,在量热过程中存在能量释放 ;随着活化时间的增加 ,能量释放依次增加 ;在不同气氛下 ,机械活化闪锌矿能量释放基本一致。量热前后其晶体结构不变 ,但能量释放后颗粒变粗 ,细粒子明显减少 ,表面积减小 ,初步认为该能量释放是由于温度升高导致细粒子团聚 ,表面积减少而引起的。

The thermal behavior of mechanically activated sphalerite during ageing was investigated by calorimetry, TEM, XRD and particle size analysis. The calorimetric results indicate that mechanically activated sphalerite can release the storage energy during calorimetric process. The amount of releasing energy increases with the grinding time and almost remains constant after grinding for a certain time. The release of energy is independent of grinding atmosphere. XRD results show that there is a great difference of microstructure between activated and non-activated sphalerite but the microstructure remains the same after the activated sphalerite is heated in calorimeter for the measurement of the releasing energy. The TEM test shows that particle size of the activated sphalerite becomes larger at heated in calorimeter. Therefore it can be concluded that the releasing energy come from the decrease of the specific surface energy.