Solubility and Modeling of Li2SO4·H2O in Aqueous H2SO4–MgSO4 Solutions for Lithium Extraction from Spodumene
Solubility and Modeling of Li2SO4·H2O in Aqueous H2SO4–MgSO4 Solutions for Lithium Extraction from Spodumene
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DOI：
10.1021/acs.jced.2c00022
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发表时间：
2022-04
期刊：
影响因子：
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通讯作者：
Xiaojuan Zhang;Xiangzhao Zeng;Youna Shan;Zhibao Li;Yan Zeng;E. Asselin
中科院分区：
文献类型：
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作者：
Xiaojuan Zhang;Xiangzhao Zeng;Youna Shan;Zhibao Li;Yan Zeng;E. Asselin
从锂辉石（LiAlSi 2 O 6）中提取锂对于满足用于电能存储的锂离子电池日益增长的需求具有重要意义。然而，锂辉石的常规加工在中和步骤期间涉及H2SO 4的巨大消耗。我们提出了一种新的流程，通过增加冷却结晶步骤将硫酸锂结晶为Li 2SO 4·H2O来避免浪费H2SO 4。为了促进该工艺的发展，采用动态法测定了283.15 ~ 353.15 K范围内Li 2SO 4·H2O在H2SO 4-MgSO 4-H2O体系中的溶解度。通过回归混合溶剂电解质模型参数进行溶解度的化学建模，平均绝对相对偏差小于2%。该模型能够在较宽的浓度和温度范围内计算Li 2SO 4·H2O在H2SO 4-MgSO 4水溶液中的溶解度。在浓H2SO 4中进行了Li 2SO 4·H2O的冷却结晶实验，证明了其可行性。
Lithium extraction from spodumene (LiAlSi2O6) is of great importance to meet the increasing demand for lithium-ion batteries used in electric energy storage. However, conventional processing of spodumene involves enormous consumption of H2SO4during the neutralization step. We propose a new flowsheet to avoid wasting H2SO4by adding a cooling crystallization step to crystallize lithium sulfate as Li2SO4·H2O. To advance the process development, the solubilities of Li2SO4·H2O in the system H2SO4–MgSO4–H2O from 283.15 to 353.15 K were measured experimentally via a dynamic method. Chemical modeling for the solubility was carried out by regressing the mixed solvent electrolyte model parameters with the average absolute relative deviation of less than 2%. The newly built model is capable of calculating the solubility of Li2SO4·H2O in aqueous H2SO4–MgSO4solutions in wide concentration and temperature ranges. Cooling crystallization of Li2SO4·H2O in concentrated H2SO4was conducted and its feasibility was proved.