四元体系Na^(+)//F^(-),CO_(3)^(2-),PO_(4)^(3-)-H_(2)O的相平衡研究  

Phase Equilibrium Study of Quaternary System Na^(+)//F^(-),CO_(3)^(2-),PO_(4)^(3-)-H_(2)O

作　　者：卢子钰 刘永刚 马瑞峰 柳召刚[1] 胡艳宏[1] 吴锦绣[1] Lu Ziyu;Liu Yonggang;Ma Ruifeng;Liu Zhaogang;Hu Yanhong;Wu Jinxiu(School of Materials and Metallurgy,Inner Mongolia University of Science and Technology,Inner Mongolia Autonomous Region Key Laboratory of Rare Earth Hydrometallurgy and Light Rare Earth Application,Key Laboratory of Green Extraction and Efficient Utilization of Light Rare Earth Resources,Ministry of Education,Baotou 014010,China)

机构地区：[1]内蒙古科技大学材料与冶金学院,内蒙古自治区稀土湿法冶金与轻稀土应用重点实验室,轻稀土资源绿色提取与高效利用教育部重点实验室,内蒙古包头014010

出　　处：《中国稀土学报》2022年第6期1098-1106,共9页Journal of the Chinese Society of Rare Earths

基　　金：国家自然科学基金项目(51634005)资助。

摘　　要：包头稀土矿湿法工艺中氟、磷的回收是行业难题,目前对废水中氟、磷钠盐的回收率低、分离成本高。本文采用等温溶解平衡法研究了四元体系Na^(+)//F^(-),CO_(3)^(2-),PO_(4)^(3-)-H_(2)O在298.15,318.15和333.15 K的相平衡。并测定了该体系的溶解度和平衡液相密度,采用X射线衍射法测定了平衡固相。绘制了四元体系Na^(+)//F^(-),CO_(3)^(2-),PO_(4)^(3-)-H_(2)O干基图、水图和密度组成图。结果表明,四元体系Na^(+)//F^(-),CO_(3)^(2-),PO_(4)^(3-)-H_(2)O干基图属于简单四元相图,相图中包含1个共饱点,4条单变量曲线,3个单盐结晶区(NaF,Na_(2)CO_(3)·H_(2)O,Na_(3)PO_(4)·8H_(2)O)和1个复盐结晶区(Na7F(PO_(4))_(2)·19H_(2)O);共饱点平衡固相中均包含NaF,Na_(2)CO_(3)·H_(2)O,Na_(7)F(PO_(4))_(2)·19H_(2)O。The recovery of fluorine and phosphorus in the wet process of Baotou rare earth mine is an industry problem.At present,the recovery rate of fluorine and phosphorus sodium salts in wastewater is low and the separation cost is high.In this paper,the isothermal dissolution equilibrium method was used to study the phase equilibria of Na^(+)//F^(-),CO_(3)^(2-),PO_(4)^(3-)-H_(2)O in quaternary system at 298.15,318.15 and 333.15 K,respectively,and measure the solubility and equilibrium liquid density of the system.And the equilibrium solid phase was measured by X-ray diffraction.The dry basis diagram,water diagram and density composition diagram of the quaternary system Na^(+)//F^(-),CO_(3)^(2-),PO_(4)^(3-)-H_(2)O were drawn.The results show that the dry basis diagram of the quaternary system Na^(+)//F^(-),CO_(3)^(2-),PO_(4)^(3-)-H_(2)O belongs to the simple quaternary phase diagram,and the phase diagram contains 1 co-saturation point,4 univariate curves,3 single salt crystals’s zones(NaF,Na_(2)CO_(3)·H_(2)O,Na_(3)PO_(4)·8H_(2)O)and a double salt crystallization zone(Na_(7)F(PO_(4))_(2)·19H_(2)O);the eutectic equilibrium solid phase contains NaF,Na_(2)CO_(3)·H_(2)O,Na_(7)F(PO_(4))_(2)·19H_(2)O.

关 键 词：水盐相图 相平衡 氟化钠 磷酸钠 包头稀土矿 

分 类 号：O642.42[理学—物理化学]