物理化学学报 >> 2015, Vol. 31 >> Issue (10): 1853-1863.doi: 10.3866/PKU.WHXB201508121

热力学,动力学和结构化学 上一篇    下一篇

MgO-P2O5和CaO-P2O5体系的热力学优化

丁国慧1,谢伟1,JUNGIn-Ho2,乔芝郁1,杜广巍1,曹战民1,*()   

  1. 1 北京科技大学钢铁冶金新技术国家重点实验室,冶金与生态工程学院,北京100083
    2 麦吉尔大学矿业与材料工程系,蒙特利尔QC H3A 0C5,加拿大
  • 收稿日期:2015-04-30 发布日期:2015-10-10
  • 通讯作者: 曹战民 E-mail:zmcao@ustb.edu.cn
  • 基金资助:
    国家重点基础研究发展规划项目(973)(2014CB643401)

Thermodynamic Assessment of the MgO-P2O5 and CaO-P2O5 Systems

Guo-Hui. DING1,Wei XIE1,In-Ho JUNG2,Zhi-Yu QIAO1,Guang-Wei DU1,Zhan-Min CAO1,*()   

  1. 1 State Key Laboratory of Advanced Metallurgy, School of Metallurgical and Ecological Engineering, University of Science & Technology Beijing, Beijing 100083, P. R. China
    2 Department of Mining and Materials Engineering, McGill University, Montreal QC H3A 0C5, Canada
  • Received:2015-04-30 Published:2015-10-10
  • Contact: Zhan-Min CAO E-mail:zmcao@ustb.edu.cn
  • Supported by:
    the National Key Basic Research Program of China (973)(2014CB643401)

摘要:

基于严格评估的相图和热力学实验数据,采用相图计算方法对MgO-P2O5和CaO-P2O5体系进行热力学优化.液相采用修正的似化学模型进行描述,考虑了对近似处理液相中存在的短程有序.为了描述M3(PO4)2(M = Mg, Ca)组分处的最大短程有序,将PO43-当作液相中P2O5的基本组成单元.体系中所有的中间相都看作线性化合物并考虑了晶型转变.获得一套合理、可靠、自洽的模型参数用来描述体系中各相的热力学性质,在实验误差范围内很好地重现了相图、焓、熵和活度实验数据,为炼钢脱磷过程中熔渣体系热力学数据库的建立打下了坚实的基础.

关键词: MgO-P2O5, CaO-P2O5, 修正的似化学模型, 热力学, 相图

Abstract:

The MgO-P2O5 and CaO-P2O5 systems have been thermodynamically assessed based on the available phase diagram and thermodynamic data using the Calculation of Phase Diagram (CALPHAD) method. The liquid phase is described by the modified quasichemical model with the pair approximation, which takes short-range ordering in liquid solution into account. The PO43- is considered as the basic building unit of P2O5 in the liquid solution since the maximum short-range ordering occurs at the M3(PO4)2 (M = Mg, Ca) composition. All intermetallic phases are treated as stoichiometric compounds and the phase transformations are considered. A set of self-consistent model parameters is obtained to describe the thermodynamic property of every phase in these two binary systems, by which the published phase diagram, enthalpy, entropy, and activity data are reproduced well within experimental error limits. The present study can be used as a basis for the development of a thermodynamic database of molten slag system for the steelmaking dephosphorus process.

Key words: MgO-P2O5, CaO-P2O5, Modified quasichemical model, Thermodynamics, Phase diagram

MSC2000: 

  • O642