Abstract Lithium carbonate precipitation from a Li2SO4 solution in a stirred crystallizer in semi-batch processes was investigated and compared using a heterogeneous CO2 reaction and homogeneous Na2CO3 reaction. Nucleation and crystal growth were successfully monitored by an inline Particle Track based on the focused beam reflectance measurement technique. The results obtained indicate that the particle size decreased with an increase in mixing speed for both precipitation processes. However, the CO2 feed rate in the heterogeneous reaction and the pumping rate of Na2CO3 in the homogeneous reaction did not have a significant impact on the particle size distribution. Temperature and the final pH play critical roles in precipitation when using CO2 as a reactant. High alkaline conditions are needed to induce heterogeneous precipitation. The lithium recovery with homogeneous precipitation was higher than with heterogeneous precipitation, probably due to the gas-liquid mass transfer phenomena of absorption influencing carbon dioxide conversion to carbonate ions in heterogeneous precipitation. Agglomerates of leaf-shaped primary crystals were mainly obtained.

中文翻译：

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通过均相和非均相反应结晶沉淀碳酸锂

摘要 使用非均相 CO2 反应和均相 Na2CO3 反应研究和比较了半间歇过程中从 Li2SO4 溶液中的 Li2SO4 溶液中沉淀碳酸锂。成核和晶体生长通过基于聚焦光束反射测量技术的在线粒子跟踪成功监测。获得的结果表明，对于两种沉淀过程，颗粒尺寸随着混合速度的增加而减小。然而，非均相反应中的 CO2 进料速率和均相反应中 Na2CO3 的泵送速率对粒度分布没有显着影响。当使用 CO2 作为反应物时，温度和最终 pH 在沉淀中起着关键作用。需要高碱性条件来诱导异质沉淀。均相沉淀的锂回收率高于非均相沉淀，这可能是由于吸收的气液传质现象影响了非均相沉淀中二氧化碳转化为碳酸根离子。主要获得叶形初级晶体的附聚物。