Optimization of lithium extraction solar pond in Zabuye Salt Lake: Theoretical calculation combined with field experiments

Abstract

This research optimized the structure of lithium extraction solar ponds to enhance the crystallization rate and yield of Li₂CO₃. Using the response surface methodology in Design-Expert 10.0.3, the authors conducted experiments to investigate the influence of four factors related to solar pond structure on the crystallization of Li₂CO₃ and their pairwise interactions. Computational Fluid Dynamics (CFD) simulations of the flow field within the solar pond were performed using COMSOL Multiphysics software to compare temperature distributions before and after optimization. The results indicate that the optimal structure for lithium extraction from the Zabuye Salt Lake solar ponds includes UCZ (Upper Convective Zone) thickness of 53.63 cm, an LCZ (Lower Convective Zone) direct heating temperature of 57.39°C, a CO₃^2- concentration of 32.21 g/L, and an added soda ash concentration of 6.52 g/L. Following this optimized pathway, the Li₂CO₃ precipitation increased by 7.34% compared to the initial solar pond process, with a 33.33% improvement in lithium carbonate crystallization rate. This study demonstrates the feasibility of optimizing lithium extraction solar pond structures, offering a new approach for constructing such ponds in salt lakes. It provides valuable guidance for the efficient extraction of lithium resources from carbonate-type salt lake brines.

Keywords

Salt lake / Solar pond / Lithium extraction / Crystallization rate / Box-Behnken / Computational fluid dynamicsResponse surfaceZabuye salt lake / Mineral exploration engineering

CRediT authorship contribution statement

Tao Ding, Qian Wu, Jiang-jiang Yu, Ling-zhong Bu, Yunsheng Wang, En-yuan Xing and Yu-bin Li prepared the manuscript. Tao Ding drew all the figures. Zhen Nie and Mian-ping Zheng supervised the findings of this work. All authors discussed the results and contributed to the final manuscript.

Declarations of interest

The authors declare no conflicts of interest.

Acknowledgement

The author thanks the reviewers and editors who participated in the manuscript review. This study was supported by the National Natural Science Foundation of China (U20A20148) and the Major Science and Technology Projects of the Xizang (Tibet) Autonomous Region (XZ202201ZD0004G and XZ202201ZD0004G01).

References

[1] Abdullah AA, Fallatah HM, Lindsay KA, Oreijah MM. 2017. Measurements of the performance of the experimental salt-gradient solar pond at Makkah one year after commissioning. Solar energy, 150, 212-219. doi: 10.1016/j.solener.2017.04.040.

[2] Alcaraz A, Montalà M, Cortina JL, Akbarzadeh A, Aladjem C, Farran A, Valderrama C. 2018. Design construction and operation of the first industrial salinity-gradient solar pond in Europe: An efficiency analysisperspective. Solarenergy, 164,316-326.doi: 10.1016/j.solener.2018.02.053.

[3] Alcaraz A, Montala M, Valderrama C, Cortina JL, Akbarzadeh A, Farran A. 2018. Increasing the storage capacity of a solar pond by using solar thermal collectors: Heat extraction and heat supply processes using in-pond heat exchangers. Solar Energy, 171, 112-121. doi: 10.1016/j.solener.2018.06.061.

[4] Bisht S, Dhindsa GS, Sehgal SS. 2020. Augmentation of diurnal and nocturnal distillate of solar still having wicks in the basin and integrated with solar pond. Materials Today Proceedings, 33(3), 1615-1619. doi: 10.1016/j.matpr.2020.05.732.

[5] Bozkurt I, Deniz S, Karakilcik M, Dincer I. 2015. Performance assessment of a magnesium chloride saturated solar pond. Renewable Energy, 78, 35-41. doi: 10.1016/j.renene.2014.12.060.

[6] Ding T, Zheng MP, Nie Z, Ma LC, Ye CY, Wu Q, Zhao YY, Yang DH, Wang K. 2022. Impact of regional climate change on the development of lithium resources in Zabuye Salt Lake, Tibet. Frontiers in Earth Science, 10, 865158. doi: 10.3389/feart.2022.865158.

[7] Ding T, Zheng MP, Peng SP, Lin YH, Zhang XF, Li MM. 2023. Lithium extraction from salt lakes with different hydrochemical types in the Tibet Plateau. Geoscience Frontiers, 14(1), 101485. doi: 10.1016/j.gsf.2022.101485.

[8] Ding T, Zheng MP, Peng SP, Nie Z, Lin YH, Wu Q. 2022. Recovery of lithium ions from salt lakes using nanofibers containing zeolite carriers. Frontiers in Energy Research, 10, 895681. doi: 10.3389/fenrg.2022.895681.

[9] Kaushika ND. 1984. Solar Pond: A review. Energy Conversation and Management. 353-376. doi: 10.1016/0196-8904(84)90016-5.

[10] Li N, Wang Q, Liu JW. 2021 Experimental study on effect of nanoparticles on thermal performance of salt gradient solar pond. Thermal Science and Technology, 2021, 20(2), 122-127. doi. 10.13738/j. issn.1671-8097.020106 (in Chinese).

[11] Nie Z, Bu LZ, Zheng MP, Huang WN. 2011. Experimental study of natural brine solar ponds in Tibet. Solar Energy, 85(7), 1537-1542. doi: 10.1016/j.solener.2011.04.011.

[12] Nie Z, Wu Q, Ding T, Bu LZ. 2022. Research progress on industrialization technology of lithium extraction from salt lake brine in China. Inorganic Chemicals Industry, 54(10), 1-12.

[13] Rioyo J, Tuset S, Grau R. 2022. Lithium extraction from spodumene by the traditional sulfuric acid process: A review. Mineral Processing and Extractive Metallurgy Review, 43(1), 97-106. doi: 10.1080/08827508.2020.1798234.

[14] Sayer AH, Al-Hussaini H, Campbell AN. 2018. New comprehensive investigation on the feasibility of the gel solar pond, and a comparison with the salinity gradient solar pond. Applied Thermal Engineering, 130, 672-683. doi: 10.1016/j.applthermaleng.2017.11.056.

[15] Tahat MA, Kodah ZH, Probert SD, Tahaineh AI. 2000. Performance of a portable mini solar-pond. Applied energy, 66(4), 299-310. doi: 10.1016/S0306-2619(00)00021-0.

[16] Tang LJ, Zheng MP, Liu JH. 2009. Crystallization experiment of carbonate salt lake brine in simulated solar pool. Acta Geologica Sinica, 30(2), 249-255 (in Chinese).

[17] Wang J, Wang L, Xu H, Sheng L, He XM. 2024. Perception of fundamental science to boost lithium metal anodes toward practical application. Green Energy & Environment, 9(3), 454-472. doi: 10.1016/j.gee.2023.02.008.

[18] Wu Q, Yu JJ, Bu LZ, Nie Z, Wang Y, Renchen N, He T, Zhang K, Zhang JT, He ZK. 2022. The application of an enhanced salinitygradient solar pond with nucleation matrix in lithium extraction from Zabuye salt lake in Tibet. Solar Energy, 244, 104-114. doi: 10.1016/j.solener.2022.08.031.

[19] Yu JJ, Zheng MP, Tang LJ. 2013. Comparison of lithium extraction from carbonate brine by laboratory simulation and solar pond. Advances in Chemical Industry, 32(6), 1248-1252 (in Chinese).

[20] Zheng MP, Xing EY, Zhang XF, Li MM, Che D, Bu LZ, Han JH, Ye CY. 2023. Classification and mineralization of global lithium deposits and lithium extraction technologies for exogenetic lithium deposits. China Geology, 6(4), 547-566. doi: 10.31035/cg2023061.