Solid-liquid Phase Equilibria in the Process of Producing Lithium Hydroxide from Lithium Sulfate

• 来源期刊: 高等学校化学研究（英文版）
• 年，卷（期）: 2019,（6）
• 页码范围: 1018-1023
• 页数: 6页
• 语种: 英文
• DOI: 10.1007/s40242-019-9197-z

摘要

The solid-liquid phase equilibria in the process of producing lithium hydroxide from lithium sulfate at 283.15,298.15 and 323.15 K were studied via the isothermal solubility equilibrium method,and the solid species,phase diagrams,solution densities and pH were determined.The results show that four solid species of Na2SO4·10H2O,Na2SO4·2.5H2O,Na2SO4 and LiOH·H2O occurred in the system,among them,Na2SO4·2.5H2O was a new solid species not reported in the open literature,which was determined via chemical analysis,Karl Fischer water titration,X-ray diffraction(XRD),thermogravimetic analysis(TG) and differential scanning calorimetry(DSC) testing.Based on the SLE data,one systemic process to produce LiOH·H2O from Li2SO4·H2O was proposed including two crystallization steps at lower and higher temperatures.