CIESC Journal ›› 2018, Vol. 69 ›› Issue (7): 2838-2850.DOI: 10.11949/j.issn.0438-1157.20171315

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Phase equilibria in systems K+, NH4+//Cl-, SO42--H2O and K+, NH4+//Cl-, SO42--H2O at 313.15 K

REN Yongsheng1,2, HE Tingting1,2, XIE Juan1,2, CAI Chao1,2   

  1. 1 State Key Laboratory of High-efficiency Coal Utilization and Green Chemical Engineering, Yinchuan 750021, Ningxia, China;
    2 School of Chemistry & Chemical Engineering, Ningxia University, Yinchuan 750021, Ningxia, China
  • Received:2017-09-27 Revised:2018-03-13 Online:2018-07-05 Published:2018-07-05
  • Supported by:

    supported by the National First-Rate Discipline Construction Project of Ningxia (NXYLXK2017A04), the Self-Topic Fund of State Key Laboratory of High-efficiency Coal Utilization and Green Chemical Engineering (2017CET04KY01) and the Postgraduate Innovative Projects of Ningxia University (GIP2017025).

333.15 K K+,NH4+//Cl-,SO42--H2O和K+,NH4+//Cl-,SO42--(CH2OH)2-H2O体系固液相平衡

任永胜1,2, 何婷婷1,2, 谢娟1,2, 蔡超1,2   

  1. 1 省部共建煤炭高效利用与绿色化工国家重点实验室, 宁夏 银川 750021;
    2 宁夏大学化学化工学院, 宁夏 银川 750021
  • 通讯作者: 任永胜
  • 基金资助:

    宁夏回族自治区“化学工程与技术”一流学科建设项目(NXYLXK2017A04);省部共建煤炭高效利用与绿色化工国家重点实验室自主课题项目(2017CET04KY01);宁夏大学研究生创新项目(GIP2017025)。

Abstract:

An experimental study on phase equilibria in the system (K+, NH4+//Cl-, SO42--H2O) and (K+, NH4+//Cl-, SO42--(CH2OH)2-H2O) is done by the method of isothermal solution saturation. In these systems, the initial mass fraction of ethylene glycol is 30% in the salt-free binary solvent water + ethylene glycol. The solubilities, densities, viscosities, and refractive indices of saturated solutions have been measured for the two systems. On the basis of the experimental data, corresponding phase diagrams and diagrams of physical properties versus composition were plotted. All the physical properties of both systems change regularly with concentration change of the liquid phase. The phase diagram of (K+, NH4+//Cl-, SO42--H2O) consists of one invariant point, four univariant curves, and four solid phase crystallization regions at 333.15 K. The phase diagram of (K+, NH4+//Cl-, SO42--(CH2OH)2-H2O) is similar to the previous one, which contains one invariant point, four univariant curves, and four solid phase crystallization regions at 333.15 K. Comparisons of the stable phase diagrams for (K+, NH4+//Cl-, SO42--H2O) and (K+, NH4+//Cl-, SO42--(CH2OH)2-H2O) at 333.15 K are shown that they all have four solid solutions[respectively (K, NH4)Cl, (NH4, K)Cl, (K, NH4)2SO4 and (NH4, K)2SO4)]. These changes between phase diagrams at different solvents will be very useful for extracting the salts. According to this work, the measured data and phase equilibrium diagrams can be used for a new technology to design and optimize the production of K2SO4, from mother liquor of calcium carbonate whiskers prepared by FGD gypsum. At the same time, it can provide fundamental data support for chemical industry development.

Key words: ethylene glycol, K2SO4, phase equilibria, physical properties, solid solutions

摘要:

采用等温溶解法研究333.15 K体系(K+,NH4+//Cl-,SO42--H2O)和(K+,NH4+//Cl-,SO42--(CH2OH)2-H2O)[w((CH2OH)2)=30%]的固液相平衡关系。测定了平衡溶液的溶解度数据及物化性质,包括密度、黏度、折射率、pH。根据实验数据,绘制了相应的干盐相图、水图及物化性质-组成图。实验中的物化性质(黏度、密度、折射率、pH)随J(2NH4+)的变化呈现相似性规律。实验结果表明:在333.15 K下,体系(K+,NH4+//Cl-,SO42--H2O)和(K+,NH4+//Cl-,SO42--(CH2OH)2-H2O)[w((CH2OH)2)=30%]的相图相似,均含有一个四元共饱和点,四条单变曲线及四个固相结晶区域。这两个体系均为复杂体系,存在(K,NH4)Cl、(NH4,K)Cl、(K,NH42SO4、(NH4,K)2SO4四种固溶体。实验所获数据和结论,可优化以硫酸盐型固体废弃物为硫酸根来源,转化法生产硫酸钾工艺。

关键词: 乙二醇, 硫酸钾, 相平衡, 物理性质, 固溶体

CLC Number: