摘要
本文采用DTA-TG热分析及动力学计算对四川万源庙子的毒重石贫、富矿在700～1000℃下的热分解行为及其机理进行研究.万源庙子的毒重石贫矿在720～815℃,815～910℃发生分解,第一步由n为1的成核与生长机制控制,热分解机制方程式为：-1n（1-a）,E为261.9kJ/mol,A为3.8788×10^10,第二步在由三维扩散,3D（球对称）机制控制,热分解机制方程式为：[1-（1-a）^1/3]^2,E为265.2kJ/mol,A为1.5498×10^9.富矿在700～1000℃也分两步,第一步在760～840℃;第二步在850～980℃,此两步被分解物及分解产物同贫矿一样,富矿第一步是界面收缩的圆柱形对称机制控制,热分解机制方程式为：1-（1-a）^1/3,E为206.1kJ/mol,A为4.7042×10^5.富矿第二步是以收缩的圆柱形对称和三维扩散,3D（圆柱形对称）的机理联合控制.
The decomposition behavior and mechanism of low-grade and high-grade witherit from Sichuan Wanyuan miaozi are studied by using thermal analysis and kinetics compute in this paper. The low-grade witherit of Wanyuan miaozi decomposed at 720-815℃ and 815- 910℃ .The first step of decomposition was controlled by nuclear producing and growing process（n = 1）, the decomposition mechanism may be expressed as follows： - In（1 - a）, E = 261. 9kJ/mol, A = 3. 8788 × 10^10. The second step of decomposition was controlled by three-dimensional diffuse （ball symmetry）, the decomposition mechanism may be expressed as follows： [ 1 （1 - a）^1/3]^2, E = 265.2kJ/mol,A= 1. 5498 × 10^9. The high-grade witherit of wanyuan miaozi also decomposed at 760-840℃ and 850-980℃ .The decomposed and decomposing matters of high-grade witherit were same as low-grade witherit, The first step of decomposition of high-grade witherit was controlled by boundary surface contraction（column symmetry）, the decomposition mechanism may be expressed as follows： 1 （1 - a）^1/3, E- 206. 1kJ/mol,A= 4.7042×10^5. The second step of decomposition was controlled by boundary surface contraction （column symmetry） and three-dimensional diffuse （column symmetry）.
出处
《矿冶》
CAS
2006年第2期85-88,96,共5页
Mining And Metallurgy
基金
四川省重点攻关资助项目(03GG021-002)
关键词
毒重石
热分解
动力学
钡解石
钡白云石
witherite
decomposition
kinetics
barytocalcite
barytodolomite
