30℃时MgCl_2-MgSO_4-CH_3CH_2OH-H_2O四元体系液固相平衡的研究  

Study on the Liquid-Solid Phase Equilibrium of Quaternary System MgCl_2-MgSO_4-CH_3CH_2OH-H_2O at 30℃

作　　者：张晓菲[1] 武朝军[1] 刘人铭[1] 李学芳[1] 

机构地区：[1]内蒙古工业大学化工学院,呼和浩特010051

出　　处：《化学通报》2015年第3期247-253,共7页Chemistry

摘　　要：采用等温法测定了30℃时Mg Cl2-Mg SO4-CH3CH2OH-H2O四元体系及边界三元体系Mg Cl2-CH3CH2OH-H2O和Mg SO4-CH3CH2OH-H2O的相平衡数据,绘制了相图并划分了相应的结晶区。实验结果表明,随着乙醇-水体积比不同,四元体系Mg Cl2-Mg SO4-CH3CH2OH-H2O出现了不同的结晶区,随着乙醇含量的增加,Mg Cl2和Mg SO4的溶解度越来越小,不饱和区越来越小,体系中平衡固相的结晶水含量越来越低,说明乙醇具有一定的盐析作用和脱水作用。当乙醇-水体积比为5∶5时,是获得镁盐的最佳比例。这为芒硝和白钠镁矾共生矿中镁盐的分离和提纯提供基础的理论数据。Using isothermal method,the phase equilibrium for quaternary system Mg Cl2-Mg SO4-CH3CH2OHH2 O and its boundary systems Mg Cl2-CH3CH2OH-H2 O and Mg SO4-CH3CH2OH-H2 O at 30℃ were determined.Then,phase diagram is drawn and divided the corresponding crystallization zone. For Mg Cl2-Mg SO4-CH3CH2OHH2 O in the alcohol-water system with different volume ratio,the system appears many different crystalline regions. As increasing the ethanol-water volume ratio,the solubilities of Mg Cl2 and Mg SO4 are decreased and the unsaturated region become smaller,the hydrate brings less crystal water,these results indicate that ethanol has salting-out and dehydration effect. The optimal proportion of magnesium salt can be gained when the ethanol-water volume ratio of quaternary system is 5 ∶ 5. This experiment provides the thermodynamic data of separation and purification of magnesium salt from paragenetic mineral of mirabilite and bloedite.

关 键 词：氯化镁 硫酸镁 乙醇 平衡 

分 类 号：O642.42[理学—物理化学]