无机盐工业
主管:中海油天津化工研究设计院有限公司
主办:中海油天津化工研究设计院有限公司
   中海油炼油化工科学研究院(北京)有限公司
   中国化工学会无机酸碱盐专业委员会
ISSN 1006-4990 CN 12-1069/TQ
研究与开发

三元体系Na2CO3-NaF-H2O 298.15 K和318.15 K相平衡研究

  • 卢子钰 ,
  • 柳召刚 ,
  • 吴锦绣 ,
  • 胡艳宏 ,
  • 刘兴宇
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  • 1.内蒙古科技大学材料与冶金学院,内蒙古包头 014010
    2.轻稀土资源绿色提取与高效利用教育部重点实验室
    3.内蒙古自治区稀土湿法冶金与轻稀土应用重点实验室
    4.内蒙古大学化学与化工学院
卢子钰(1994— ),男,硕士研究生,主要研究方向为稀土冶金及溶液相平衡研究;E-mail: 540326376@qq.com

收稿日期: 2021-04-13

  网络出版日期: 2022-03-18

基金资助

国家自然科学基金重点项目(51634005)

Study on phase equilibrium of ternary system of Na2CO3-NaF-H2O at 298.15 K and 318.15 K

  • Ziyu LU ,
  • Zhaogang LIU ,
  • Jinxiu WU ,
  • YanHong HU ,
  • Xingyu LIU
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  • 1. School of Materials and Metallurgy,Inner Mongolia University of Science and Technology,Baotou 014010,China
    2. Key Laboratory of the Ministry of Education for Green Extraction and Efficient Utilization of Light Rare Earth Resources
    3. Key Laboratory of Rare Earth Hydrometallurgy and Light Rare Earth Application,Inner Mongolia Autonomous Region
    4. Inner Mongolia University of Chemistry and Chemical Engineering

Received date: 2021-04-13

  Online published: 2022-03-18

摘要

在稀土提取工艺和氟化钠制备过程中会产生含碳酸钠和氟化钠的废水。研究了三元体系Na2CO3-NaF-H2O的相平衡,为回收氟化钠和碳酸钠提供理论指导。采用等温溶解平衡法研究了三元体系Na2CO3-NaF-H2O在298.15 K和318.15 K的相平衡关系,测定了该体系各物质组分的溶解度以及平衡液相的密度和pH,并根据溶解度数据绘制相图以及物化参数-组分含量的关系图,利用X射线衍射(XRD)对固相进行分析表征。实验研究表明:该体系无复盐和固溶体生成,属于水合物I型相图。相图包含1个全液相区、2个单盐结晶区、1个混合结晶区、1个全固相区以及3条单变量溶解度曲线、1个共饱点。碳酸钠对氟化钠具有较强的盐析作用。温度不变时,碳酸钠质量分数越高溶液密度越大、pH越大;碳酸钠质量分数不变时,温度越高溶液密度越大、pH越小。

本文引用格式

卢子钰 , 柳召刚 , 吴锦绣 , 胡艳宏 , 刘兴宇 . 三元体系Na2CO3-NaF-H2O 298.15 K和318.15 K相平衡研究[J]. 无机盐工业, 2022 , 54(3) : 66 -70 . DOI: 10.19964/j.issn.1006-4990.2021-0240

Abstract

Wastewater containing sodium carbonate and sodium fluoride will be generated in the rare earth extraction process and the preparation process of sodium fluoride.The phase equilibrium of the ternary system of Na2CO3-NaF-H2O was studied to provide theoretical guidance for the preparation of practical production and recovery of sodium fluoride and sodium carbon-ate.The isothermal dissolution equilibrium method was used to study the phase equilibrium relationship of the ternary system of Na2CO3-NaF-H2O at 298.15 K and 318.15 K.The solubility of each component of the system and the density and pH of the equilibrium liquid phase were measured.The phase diagram and the relationship between physicochemical parameters and content of component were drawn according to the solubility data.The solid phase was analyzed and characterized by X-ray diffraction(XRD).The experimental study showed that the system had no double salt and solid solution,and belonged to the I-type phase diagram of hydrate.The phase diagram included 1 all-liquid region,2 single-salt crystallization regions,1 mixed crystallization region,1 all-solid region,3 univariate solubility curves,and 1 co-saturation point.Na2CO3 had a strong salting-out rate for NaF.When the temperature was constant,the mass fraction of Na2CO3 was higher,the density was greater,and the pH of the solution was greater.When the mass fraction of Na2CO3 was constant,the temperature was higher,the density was greater,and the pH of the solution was lower.

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