In this study,the gas-liquid reactive crystallization of LiCl-NH3·H2O-CO2 was adopted to produce Li2CO3.The weakly alkaline nature of NH3·H2O in the absence of any recarbonation process resulted in a unimoda...In this study,the gas-liquid reactive crystallization of LiCl-NH3·H2O-CO2 was adopted to produce Li2CO3.The weakly alkaline nature of NH3·H2O in the absence of any recarbonation process resulted in a unimodal and easily controllable particle size distribution(PSD)of the obtained Li2CO3.The reaction temperature significantly influenced both the Li2CO3 particle size and PSD.By increasing the temperature from 25 to 60℃,the volume weighted mean particle size increased from 50.5 to 100.5μm,respectively.The Li2CO3 secondary nucleation rate and growth rate were obtained by focused beam reflectance measurements and a laser particle size analyzer,respectively.The secondary nucleation rate of Li2CO3 reduced as a function of temperature,whereas the growth rate increased.In addition to improving the surface energy of the crystals to enhance the growth process,higher temperatures also reduced the supersolubility of Li2CO3,which also plays a role to decrease the secondary nucleation rate.At a constant temperature,supersaturation affects the Li2CO3 particle size through the synergistic effect of secondary nucleation and growth.Hence,with improved supersaturation,the mean particle size of Li2CO3 decreased.The results provide a meaningful way to evaluate the crystallization process and to regulate the particle size.展开更多
基金This work was partially funded by the National Key R&D Program of China(2018YFC1901801)the National Natural Science Foundation of China(51974286,51934006).
文摘In this study,the gas-liquid reactive crystallization of LiCl-NH3·H2O-CO2 was adopted to produce Li2CO3.The weakly alkaline nature of NH3·H2O in the absence of any recarbonation process resulted in a unimodal and easily controllable particle size distribution(PSD)of the obtained Li2CO3.The reaction temperature significantly influenced both the Li2CO3 particle size and PSD.By increasing the temperature from 25 to 60℃,the volume weighted mean particle size increased from 50.5 to 100.5μm,respectively.The Li2CO3 secondary nucleation rate and growth rate were obtained by focused beam reflectance measurements and a laser particle size analyzer,respectively.The secondary nucleation rate of Li2CO3 reduced as a function of temperature,whereas the growth rate increased.In addition to improving the surface energy of the crystals to enhance the growth process,higher temperatures also reduced the supersolubility of Li2CO3,which also plays a role to decrease the secondary nucleation rate.At a constant temperature,supersaturation affects the Li2CO3 particle size through the synergistic effect of secondary nucleation and growth.Hence,with improved supersaturation,the mean particle size of Li2CO3 decreased.The results provide a meaningful way to evaluate the crystallization process and to regulate the particle size.
