(中南大學(xué) 化學(xué)化工學(xué)院， 長(zhǎng)沙 410083)
摘 要: 用Friedman法研究了未活化黃鐵礦和機(jī)械活化不同時(shí)間的黃鐵礦(機(jī)械活化20min和40min的黃鐵礦分別記為黃鐵礦1和黃鐵礦2)在升溫速率分別為2.5, 5, 7.5和 15K/min下的熱分解動(dòng)力學(xué)。結(jié)果表明，未活化黃鐵礦及機(jī)械活化黃鐵礦1和黃鐵礦2的表觀活化能(E)、反應(yīng)級(jí)數(shù)(n)和指前因子(A)分別為：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。對(duì)黃鐵礦的X射線衍射譜進(jìn)行線形分析， 求取機(jī)械活化黃鐵礦1和黃鐵礦2的晶格畸變率(ε)和晶塊尺寸(D)。發(fā)現(xiàn)黃鐵礦的熱分解活化能降低與活化后黃鐵礦的晶格畸變率增大及晶塊尺寸降低有關(guān)。
關(guān)鍵字: 黃鐵礦；機(jī)械活化；熱分解動(dòng)力學(xué)；晶格畸變
of mechanically activated pyrite
ZHANG Ping-min, CHE Hong-sheng
（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
