(中南大学 化学化工学院， 长沙 410083)
摘 要: 用Friedman法研究了未活化黄铁矿和机械活化不同时间的黄铁矿(机械活化20min和40min的黄铁矿分别记为黄铁矿1和黄铁矿2)在升温速率分别为2.5, 5, 7.5和 15K/min下的热分解动力学。结果表明，未活化黄铁矿及机械活化黄铁矿1和黄铁矿2的表观活化能(E)、反应级数(n)和指前因子(A)分别为：268.612kJ/mol, 0.42, 1.094×1015 min-1; 243.725kJ/mol, 0.62, 2.008×1013min-1和177.288kJ/mol, 0.65, 5.924×1015min-1。对黄铁矿的X射线衍射谱进行线形分析， 求取机械活化黄铁矿1和黄铁矿2的晶格畸变率(ε)和晶块尺寸(D)。发现黄铁矿的热分解活化能降低与活化后黄铁矿的晶格畸变率增大及晶块尺寸降低有关。
关键字: 黄铁矿；机械活化；热分解动力学；晶格畸变
of mechanically activated pyrite
（College of Chemistry and Chemical Engineering,
Central South University, Changsha 410083, China）
Abstract:The kinetics of the thermal decompositions of mechanically activated pyrites an d non-activated pyrite were studied by using Friedman method at different heating rates of 2.5, 5, 7.5 and 15K/min in argon. Results show that the activation energies (E), reaction orders (n) and pre-exponential factors (A) for non-activated pyrite and activated pyrites are 268.612kJ/mol, 0.42 and 1.094×1015 min-1 for non-activated pyrite, 243.725kJ/mol, 0.62 and 2.008×1013 min-1 for pyrite mechanically activated for 20min (abbrev. Pyrite 1), 177.288kJ/mol, 0.65 and 5.924×109min-1 for pyrite mechanically activated for 40?min (abbrev. Pyrite 2), respectively. Comparing the integral width of X-ray diffraction peaks (220) and (440) of activated pyrites at different grinding time with that of non-activated pyrite, several values of lattice deformation (ε) and lattice size (D) of the crystallite were obtained. It is found that with the increase of grinding time the mechanical activation of the original material brings about a change in lattice parameters and deformation of the crystals of pyrite.
Key words: pyrite; mechanical activation; kinetics of thermal decomposition; deformation of lattice structure
