Na_(2)SO_(4)-(NH_(4))_(2)SO_(4)-H_(2)O三元体系相图及其应用  

Phase diagrams of the Na_(2)SO_(4)-(NH_(4))_(2)SO_(4)-H_(2)O ternary system and their application

作　　者：毕晓旭 宋继田 苏杭 石冬琦 BI Xiao-xu;SONG Ji-tian;SU Hang;SHI Dong-qi(Tianjin Key Laboratory of Integrated Design and On-line Monitoring for Light Industry & Food Machinery and Equipment,College of Mechanical Engineering,Tianjin University of Science and Technology,Tianjin 300222,China;International Science and Technology Cooperation Base of Low-Carbon Green Process Equipment,Tianjin 300222,China)

机构地区：[1]天津科技大学机械工程学院,天津市轻工与食品工程机械装备集成设计与在线监控重点实验室,天津300222 [2]低碳绿色过程装备国际联合研究中心,天津300222

出　　处：《应用化工》2022年第4期1212-1218,共7页Applied Chemical Industry

基　　金：天津市研究生科研创新项目资助(2019YJSS037);河北省省级省校科技合作项目资助(130127)。

摘　　要：使用等温溶解平衡法测定了Na_(2)SO_(4)-(NH_(4))_(2)SO_(4)-H_(2)O三元体系353.15 K下的溶解度,利用湿固相法和X射线衍射鉴定了平衡固相,绘制了该温度下的相图,利用相图分离沉钒废水中的无机盐。结果显示,353.15 K下,该三元体系为简单共饱和型,由一个共饱点、两条饱和溶解度曲线和三个固相结晶区组成。以353.15,288.15,333.15 K三元相图为指导,结晶分离出的Na_(2)SO_(4)纯度为98.95%,收率为83.17%,蒸发率为93.97%;母液经过冷却结晶提高了液相中(NH_(4))_(2)SO_(4)与Na_(2)SO_(4)比例,二次母液再次蒸发结晶分离出的(NH_(4))_(2)SO_(4)纯度为99.30%,收率为33.57%,蒸发率为50.25%。The solubility data of Na_(2)SO_(4)-(NH_(4))_(2)SO_(4)-H_(2)O at 353.15 K was determined by using isothermal dissolution equilibrium method,the equilibrium solid phase were identified by analysis of wet solid phase and X-ray diffraction,and phase diagram was draw,then the separation of inorganic salts in the vanadium wastewater was studied combing with the existing phase diagram.Results showed that ternary system was a simple eutectic type,one invariant point,two univariant curves and three crystallization fields were included in phase diagram.Based on the ternary phase diagram of 353.15,288.15 K and 333.15 K,the purity and yield of the separated Na_(2)SO_(4)was 98.95%and 83.17%,respectively,while the evaporation rate was 93.97%;The mother liquor was cooled and crystallized to increase the ratio of(NH_(4))_(2)SO_(4)to Na_(2)SO_(4) in the liquid phase,the purity and yield of the(NH_(4))_(2)SO_(4)separated by the second mother liquor was 99.30%and 33.57%respectively,while the evaporation rate was 50.25%.

关 键 词：相平衡 溶解度 相图 蒸发结晶 分离 

分 类 号：TQ115[化学工程—无机化工]