未活化与机械活化闪锌矿的氧化行为

Oxidation behaviors of unactivated and mechanically activated sphalerite

用TG分析法研究了未活化与机械活化闪锌矿在氧气氛下的氧化行为,结果表明,在400～873K之间,机械活化闪锌矿的剩余质量随着球磨时间的增加而增加,未活化闪锌矿则表现为热质量损失。用粒度分析、X射线衍射分析和重量分析法分别对机械活化闪锌矿的结构进行了表征。发现随着球磨时间的增加,机械活化闪锌矿球磨一定时间后,其比表面积基本保持不变,而晶格畸变率增大,晶块尺寸降低,且机械活化闪锌矿中的单质硫磺含量极低,可忽略不计。机械活化和未活化闪锌矿在TG曲线上的表现主要与晶格畸变率增大和晶块尺寸降低有关。

The oxidation behaviors of unactivated and mechanically activated sphalerite were investigated using thermogravimetry (TG) in oxygen. It is found that the remaining mass at 400～873 K in TG curves rises with increasing the grinding time. The surface structures were characterized by laser particle size analysis, Xray powder diffraction analysis (XRD) and gravimetric method, respectively. The specific surface area of mechanically activated sphalerites remains almost constant after a certain grinding period, and the content of elemental sulphur of mechanically activated sphalerite is determined as 5×10-4, and the lattice distortion increases, but the crystallite size decreases with increasing the grinding time. All the results imply that the mass increase at 400～850 K in the TG curve of mechanically activated sphalerite depends mainly on the increase of lattice distortion and the decrease of crystallite size with increasing grinding time.