Molecular simulations of selective adsorption of lithium in the No.6 coal seam, Junggar Coalfield

Authors

ZHANG Junshuang, College of Geological and Surveying Engineering, Taiyuan University of Technology, Taiyuan 030024, ChinaFollow
SUN Beilei, College of Geological and Surveying Engineering, Taiyuan University of Technology, Taiyuan 030024, China; Key Laboratory of Coal Science and Technology, Ministry of Education, Taiyuan University of Technology, Taiyuan 030024, ChinaFollow
ZHANG Bin, College of Mining Engineering, Taiyuan University of Technology, Taiyuan 030024, China; Key Laboratory of In-situ Property-improving Mining of Ministry of Education, Taiyuan University of Technology, Taiyuan 030024, China
LIU Chao, College of Geological and Surveying Engineering, Taiyuan University of Technology, Taiyuan 030024, China; Key Laboratory of Coal Science and Technology, Ministry of Education, Taiyuan University of Technology, Taiyuan 030024, China

Abstract

Objective With the discovery of metal deposits in coal-bearing strata, the distribution and occurrence patterns of lithium in coals have attracted much attention. However, its partitioning mode between organic structures and minerals in coals remains poorly understood.Methods This study investigated typical coals with a high lithium content in the Junggar Coalfield in Inner Mongolia. By integrating multiple simulation methods, including quantum mechanics, Monte Carlo simulation, and molecular dynamics, this study established the structural models of organic matter and inorganic minerals, as well as a visualized lithium-coal molecular structure model. Accordingly, it investigated the preferential adsorption sites on both organic matter and minerals for lithium and explored the impacts of mineral types and the metamorphic grade of organic matter on lithium adsorption during coalification and heating.Results In organic matter of coals, carboxyl groups were identified as the preferential adsorption sites for lithium ions, with the adsorption capacities of different functional groups for lithium ions decreasing in the order of carboxyl groups, hydroxyl groups, pyrrole, carbonyl groups, pyridine, and benzene rings. In the kaolinite structure, the center of the six-membered ring containing oxygen atoms within silicon-oxygen tetrahedra emerged as the preferential adsorption sites for lithium. In the case where organic matter, kaolinites, and illites coexisted, kaolinites exhibited a stronger adsorption capacity for lithium than illites under the same temperature. Meanwhile, illites showed a higher capacity to bind organic matter than kaolinites. With increasing metamorphic grade of coals, the adsorption capacity of organic matter for lithium gradually decreased. Conclusions During coalification and heating, lithium experiences repartitioning between organic matter and minerals. The evolution of its occurrence state is difficult to be directly revealed using experiments. In contrast, molecular simulations can provide abundant molecular-scale information that is difficult to obtain through experiments, thereby providing important theoretical support for the exploration, exploitation, and utilization of lithium resources in coal-bearing strata.

Keywords

molecular simulation, selective adsorption, organic matter structure, mineral structure, lithium

DOI

10.12363/issn.1001-1986.25.04.0283

Recommended Citation

ZHANG Junshuang, SUN Beilei, ZHANG Bin, et al. (2025) "Molecular simulations of selective adsorption of lithium in the No.6 coal seam, Junggar Coalfield," Coal Geology & Exploration: Vol. 53: Iss. 9, Article 9.
DOI: 10.12363/issn.1001-1986.25.04.0283
Available at: https://cge.researchcommons.org/journal/vol53/iss9/9

Reference

[1] 孙传尧，朱阳戈，宋振国，等. 我国锂铍钽铌矿产资源选冶加工现状与展望[J]. 中国工程科学，2024，26(5)：248−258.

SUN Chuanyao，ZHU Yangge，SONG Zhenguo，et al. Beneficiation，smelting and material processing of lithium，beryllium，tantalum，and niobium mineral resources in China：Current status and prospect[J]. Strategic Study of CAE，2024，26(5)：248−258.

[2] 许志琴，朱文斌，郑碧海，等. 新能源锂矿战略与大陆动力学研究：纪念南京大学地球科学与工程学院100周年华诞[J]. 地质学报，2021，95(10)：2937−2954.

XU Zhiqin，ZHU Wenbin，ZHENG Bihai，et al. New energy strategy for lithium resource and the continental dynamics research：Celebrating the centenary of the School of Earth Sciences and Engineering，Nanjing University[J]. Acta Geologica Sinica，2021，95(10)：2937−2954.

[3] 温汉捷，罗重光，杜胜江，等. 碳酸盐黏土型锂资源的发现及意义[J]. 科学通报，2020，65(1)：53−59.

WEN Hanjie，LUO Chongguang，DU Shengjiang，et al. Carbonate–hosted clay–type lithium deposit and its prospecting significance[J]. Chinese Science Bulletin，2020，65(1)：53−59.

[4] 王登红，刘丽君，刘新星，等. 我国能源金属矿产的主要类型及发展趋势探讨[J]. 桂林理工大学学报，2016，36(1)：21−28.

WANG Denghong，LIU Lijun，LIU Xinxing，et al. Main types and research trends of energy metallic resources in China[J]. Journal of Guilin University of Technology，2016，36(1)：21−28.

[5] 王登红，王瑞江，付小方，等. 对能源金属矿产资源基地调查评价基本问题的探讨：以四川甲基卡大型锂矿基地为例[J]. 地球学报，2016，37(4)：471−480.

WANG Denghong，WANG Ruijiang，FU Xiaofang，et al. A discussion on the major problems related to geological investigation and assessment for energy metal resources base：A case study of the Jiajika large lithium mineral resource base[J]. Acta Geoscientica Sinica，2016，37(4)：471−480.

[6] 张七道，蒋少涌，王微，等. 铝土岩系和煤系地层中沉积黏土型锂矿床：研究现状与展望[J]. 矿物岩石地球化学通报，2024，43(1)：90−101.

ZHANG Qidao，JIANG Shaoyong，WANG Wei，et al. Current status and prospect of researches on sediment–hosted Li deposits in bauxite formations and coal–bearing strata in China[J]. Bulletin of Mineralogy，Petrology and Geochemistry，2024，43(1)：90−101.

[7] 代世峰，刘池洋，赵蕾，等. 煤系中战略性金属矿产资源：意义和挑战[J]. 煤炭学报，2022，47(5)：1743−1749.

DAI Shifeng，LIU Chiyang，ZHAO Lei，et al. Strategic metal resources in coal–bearing strata：Significance and challenges[J]. Journal of China Coal Society，2022，47(5)：1743−1749.

[8] QIN Shenjun，ZHAO Cunliang，LI Yanheng，et al. Review of coal as a promising source of lithium[J]. International Journal of Oil，Gas and Coal Technology，2015，9(2)：215−229.

[9] ZOU Jianhua，CHENG Longfei，GUO Yuanchen，et al. Mineralogical and geochemical characteristics of lithium and rare earth elements in high–sulfur coal from the Donggou Mine，Chongqing，Southwestern China[J]. Minerals，2020，10(7)：627.

[10] DAI Shifeng，REN Deyi，CHOU Chenlin，et al. Geochemistry of trace elements in Chinese coals：A review of abundances，genetic types，impacts on human health，and industrial utilization[J]. International Journal of Coal Geology，2012，94：3−21.

[11] GUO Zhanming，SUN Beilei，LIU Chao，et al. Geochemistry of tonsteins and its implications for Li–Zr (Hf)–Nb (Ta) enrichments in Cisuralian coal seams，Shanxi Province，North China[J]. International Journal of Coal Geology，2025，300：104697.

[12] DAI Shifeng，LI Dan，CHOU Chenlin，et al. Mineralogy and geochemistry of boehmite–rich coals：New insights from the Haerwusu Surface Mine，Jungar Coalfield，Inner Mongolia，China[J]. International Journal of Coal Geology，2008，74(3/4)：185−202.

[13] DAI Shifeng，FINKELMAN R B，FRENCH D，et al. Modes of occurrence of elements in coal：A critical evaluation[J]. Earth–Science Reviews，2021，222：103815.

[14] CHEN Jian，CHEN Ping，YAO Duoxi，et al. Mineralogy and geochemistry of Late Permian coals from the Donglin Coal Mine in the Nantong Coalfield in Chongqing，Southwestern China[J]. International Journal of Coal Geology，2015，149：24−40.

[15] IKEH T J，SUN Beilei，LIU Chao，et al. Modes of occurrence and enrichment of trace elements in coal from the Anjialing Mine，Pingshuo mining district，Ningwu Coalfield，Shanxi Province，China[J]. Minerals，2022，12(9)：1082.

[16] SUN Beilei，ZENG Fangui，MOORE T A，et al. Geochemistry of two high–lithium content coal seams，Shanxi Province，China[J]. International Journal of Coal Geology，2022，260：104059.

[17] WANG Xiaomei，WANG Xiaoming，PAN Zhejun，et al. Mineralogical and geochemical characteristics of the Permian coal from the Qinshui Basin，Northern China，with emphasis on lithium enrichment[J]. International Journal of Coal Geology，2019，214：103254.

[18] SUN Yuzhuang，ZHAO Cunliang，LI Yanheng，et al. Li distribution and mode of occurrences in Li–bearing coal seam # 6 from the Guanbanwusu Mine，Inner Mongolia，Northern China[J]. Energy Exploration & Exploitation，2012，30(1)：109−130.

[19] 孙蓓蕾，孔艳磊，王国权，等. 高锂无烟煤中不同赋存态锂同位素组成趋同特征及其机理[J]. 煤炭学报，2022，47(5)：1773−1781.

SUN Beilei，KONG Yanlei，WANG Guoquan，et al. Convergence and its mechanism of lithium isotopic composition with different occurrence states in Li–rich anthracite[J]. Journal of China Coal Society，2022，47(5)：1773−1781.

[20] SUN Beilei，GUO Zhanming，LIU Chao，et al. Lithium isotopic composition of two high–lithium coals and their fractions with different lithium occurrence modes，Shanxi Province，China[J]. International Journal of Coal Geology，2023，277：104338.

[21] SONG Jia，SUN Beilei，RODRIGUES S，et al. Li concentration and isotopes in kaolinite and organic of coals determined by secondary ion mass spectrometry[J]. International Journal of Coal Geology，2025，306：104815.

[22] ZHANG Wencai，NOBLE A，YANG Xinbo，et al. Lithium leaching recovery and mechanisms from density fractions of an Illinois Basin bituminous coal[J]. Fuel，2020，268：117319.

[23] 王运泉，任德贻. 煤中微量元素研究的进展[J]. 煤田地质与勘探，1994，22(4)：16−20.

[24] PHAN T T，CAPO R C，STEWART B W，et al. Factors controlling Li concentration and isotopic composition in formation waters and host rocks of Marcellus Shale，Appalachian Basin[J]. Chemical Geology，2016，420：162−179.

[25] FINKELMAN R B，PALMER C A，WANG Peipei. Quantification of the modes of occurrence of 42 elements in coal[J]. International Journal of Coal Geology，2018，185：138−160.

[26] HOSTERMAN J W，MEYER R F，PALMER C A，et al. Chemistry and mineralogy of natural bitumens and heavy oils and their reservoir rocks from the United States，Canada，Trinidad and Tobago，and Venezuela[R]. U. S. Geological Survey，1990：1047.

[27] HE Hongtao，WANG Jinxi，XING Lecai，et al. Enrichment mechanisms of lithium in the No. 6 coal seam from the Guanbanwusu Mine，Inner Mongolia，China：Explanations based on Li isotope values and density functional theory calculations[J]. Journal of Geochemical Exploration，2020，213：106510.

[28] MU Ruifeng，WANG Shaoqing，WANG Xiaoling，et al. Organic modes of occurrence and evolution mechanism of germanium and lithium in coal：Insights from density functional theory[J]. International Journal of Coal Geology，2025，298：104661.

[29] LI Qin，LIU Xiandong，WANG Kai，et al. Revealing atomistic mechanism of lithium diffusion in montmorillonite structure：A molecular simulation study[J]. Geochimica et Cosmochimica Acta，2025，392：165−174.

[30] 孙蓓蕾，王瑶，李宝庆，等. 原位微区分析华北典型富锂煤中关键金属赋存规律[J]. 地质学报，2024，98(8)：2424−2438.

SUN Beilei，WANG Yao，LI Baoqing，et al. In–situ microanalysis of critical metal occurrences in high–lithium coals of North China[J]. Acta Geologica Sinica，2024，98(8)：2424−2438.

[31] JIU Bo，JIN Zhijun，WANG Zhaoguo. Multiscale in–situ elemental characterization of critical elements in low rank coal，implications for modes of occurrence[J]. Fuel，2023，349：128632.

[32] 左家琦. 不同尺度下不同煤级煤结构模型构建及参数演化特征研究[D]. 太原：太原理工大学，2023.

ZUO Jiaqi. Construction of structure models and parameter evolution characteristics at different scales for coals with different ranks[D]. Taiyuan：Taiyuan University of Technology，2023.

[33] BISH D L. Rietveld refinement of the kaolinite structure at 1. 5 K[J]. Clays and Clay Minerals，1993，41(6)：738–744.

[34] NEDER R B，BURGHAMMER M，GRASL T H，et al. Refinement of the kaolinite structure from single–crystal synchrotron data[J]. Clays and Clay Minerals，1999，47(4)：487−494.

[35] DRITS V A，ZVIAGINA B B，MCCARTY D K，et al. Factors responsible for crystal–chemical variations in the solid solutions from illite to aluminoceladonite and from glauconite to celadonite[J]. American Mineralogist，2010，95(2/3)：348−361.

[36] SUN Beilei，LIU Yunxia，TAJCMANOVA L，et al. In–situ analysis of the lithium occurrence in the No. 11 coal from the Antaibao mining district，Ningwu Coalfield，Northern China[J]. Ore Geology Reviews，2022，144：104825.

[37] ZHAO Lei，WARD C R，FRENCH D，et al. Origin of a kaolinite–NH₄–illite–pyrophyllite–chlorite assemblage in a marine–influenced anthracite and associated strata from the Jincheng Coalfield，Qinshui Basin，Northern China[J]. International Journal of Coal Geology，2018，185：61−78.

[38] ZHAO Lei，DAI Shifeng，NECHAEV V P，et al. Enrichment origin of critical elements (Li and rare earth elements) and a Mo–U–Se–Re assemblage in Pennsylvanian anthracite from the Jincheng Coalfield，southeastern Qinshui Basin，Northern China[J]. Ore Geology Reviews，2019，115：103184.

[39] WENDER I. Catalytic synthesis of chemicals from coal[J]. Catalysis Reviews，1976，14(1)：97−129.

[40] WISER W H. Reported in division of fuel chemistry[J]. Preprints，1975，1(20)：122−128.

[41] SPIRO C L，KOSKY P G. Space–filling models for coal. 2. Extension to coals of various ranks[J]. Fuel，1982，61(11)：1080−1084.

[42] SPIRO C L. Space–filling models for coal：A molecular description of coal plasticity[J]. Fuel，1981，60(12)：1121−1126.

[43] 邹志强，黄李金鸿，李新冬，等. 镧离子和铵离子在高岭石表面的吸附机理研究[J]. 矿冶工程，2023，43(4)：52−56.

ZOU Zhiqiang，HUANG Lijinhong，LI Xindong，et al. Adsorption mechanism of lanthanum and ammonium ions on kaolinite[J]. Mining and Metallurgical Engineering，2023，43(4)：52−56.

[44] 翁孝卿. 新型季铵盐脱硅浮选阳离子捕收剂的定向合成与定量构效关系研究[D]. 武汉：武汉理工大学，2014.

WENG Xiaoqing. Study on the quantitative structure–activity relationship and oriented synthesis of novel quaternary ammonium cationic collectors for removal of silicates[D]. Wuhan：Wuhan University of Technology，2014.

[45] 王诗生，张梦梦，盛广宏，等. 磁性生物炭吸附水中甲基橙的作用机制：基于密度泛函理论与实验研究[J]. 中国环境科学，2023，43(9)：4596−4605.

WANG Shisheng，ZHANG Mengmeng，SHENG Guanghong，et al. Adsorption mechanism of methyl orange by using the magnetic biochar：Based on density functional theory and batch adsorption experiment study[J]. China Environmental Science，2023，43(9)：4596−4605.

[46] 冯良荣，吕绍洁，邱发礼. 稀土元素掺杂对纳米TiO₂光催化剂性能的影响[J]. 复旦学报(自然科学版)，2003，42(3)：413−417.

FENG Liangrong，LYU Shaojie，QIU Fali. Influence of transition elements dopant on the photocatalytic activities of nanometer TiO₂[J]. Journal of Fudan University (Natural Science)，2003，42(3)：413−417.

[47] 常明. 煤泥悬浮液体系煤与蒙脱石相互作用的模拟研究[D]. 太原：太原理工大学，2019.

CHANG Ming. Simulation study on interaction between coal and montmorillonite in coal slurry[D]. Taiyuan：Taiyuan University of Technology，2019.

[48] XU Xingwang，ZHAI Mingguo，HONG Tao，et al. Migration–circulation processes and enrichment–mineralization mechanism of lithium–beryllium elements in the continental crust[J]. Acta Petrologica Sinica，2023，39(3)：639−658.

[49] BENSON T R，COBLE M A，RYTUBA J J，et al. Lithium enrichment in intracontinental rhyolite magmas leads to Li deposits in caldera basins[J]. Nature Communications，2017，8：270.

[50] HE Hongtao，XING Lecai，ZHANG Jingsen，et al. Binding characteristics of Cd²⁺，Zn²⁺，Cu²⁺，and Li⁺ with humic substances：Implication to trace element enrichment in low–rank coals[J]. Energy Exploration & Exploitation，2016，34(5)：735−745.

[51] YUAN Duoen，WANG Xiaomei，YAN Detian，et al. An original set of nanometer–scale mineralogical analyses of cookeite and the implications for Li enrichment：No. 2₁ coal，Mengjin Mine，western Henan[J]. International Journal of Coal Geology，2024，283：104445.

[52] LEWIŃSKA–PREIS L，FABIAŃSKA M J，ĆMIEL S，et al. Geochemical distribution of trace elements in Kaffioyra and Longyearbyen coals，Spitsbergen，Norway[J]. International Journal of Coal Geology，2009，80(3/4)：211−223.

[53] JIU Bo，HUANG Wenhui，SPIRO B，et al. Distribution of Li，Ga，Nb，and REEs in coal as determined by LA–ICP–MS imaging：A case study from Jungar Coalfield，Ordos Basin，China[J]. International Journal of Coal Geology，2023，267：104184.

[54] GAO Bin，WU Caifang，SONG Yu，et al. Structural characterization of high fidelity for bituminous and semi–anthracite：Insights from spectral analysis and modeling[J]. Fuel，2022，315：123183.

[55] 韩鹏博，徐赫，安众福，等. 聚集诱导发光[J]. 化学进展，2022，34(1)：1−130.

HAN Pengbo，XU He，AN Zhongfu，et al. Aggregation–induced emission[J]. Progress in Chemistry，2022，34(1)：1−130.

[56] 吕文婷，程运，谢浩，等. 基于密度泛函理论的高岭石吸附机理研究进展[J]. 硅酸盐通报，2020，39(1)：157−168.

LYU Wenting，CHENG Yun，XIE Hao，et al. Research progress on adsorption mechanism of kaolinite based on density functional theory[J]. Bulletin of the Chinese Ceramic Society，2020，39(1)：157−168.

[57] HINDSHAW R S，TOSCA R，GOÛT T L，et al. Experimental constraints on Li isotope fractionation during clay formation[J]. Geochimica et Cosmochimica Acta，2019，250：219−237.

[58] BODART P R，DELMOTTE L，RIGOLET S，et al. ⁷Li{¹⁹F}TEDOR NMR to observe the lithium migration in heated montmorillonite[J]. Applied Clay Science，2018，157：204−211.

[59] ZHANG Xiaoyu，KANG Tianhe，ZHANG Bin，et al. Combined molecular simulations and experimental study of methane adsorption on anthracite[J]. Energy & Fuels，2020，34(10)：12118−12125.

[60] 李勤，陆现彩，张立虎，等. 蒙脱石层间阳离子交换的分子模拟[J]. 南京大学学报(自然科学版)，2019，55(6)：879−887.

LI Qin，LU Xiancai，ZHANG Lihu，et al. Molecular simulation of interlayer cation exchange of montmorillonite[J]. Journal of Nanjing University (Natural Science)，2019，55(6)：879−887.

[61] 张双全. 煤化学[M]. 徐州：中国矿业大学出版社，2004.