Lithium extraction from mining and mineral processing wastes

Lithium extraction from mining and mineral processing wastes Lucie Bartoˇ nov´ a a,b,* , Helena Raclavsk´ a a , Barbora ˇ Sv´ edov´ a a a Centre ENET, CEET, Vˇ SB – Technical University of Ostrava, 17. Listopadu 2172/15, 708 00, Ostrava-Poruba, Czech Republic b Department of Chemistry and Physico-Chemical Processes, Faculty of Materials Science and Technology, Vˇ SB – Technical University of Ostrava, 17. Listopadu 2172/ 15, 708 00, Ostrava-Poruba, Czech Republic ARTICLE INFO Keywords: Lithium Mining waste Mineral processing Tailings Critical elements Extraction ABSTRACT Due to increased demand on energy storage sector and limited worldwide reserves of lithium, sustainable and reliable sources of this critical metal are being sought. Mining and mineral-processing wastes remain one of world’s largest waste streams and proper management of these wastes provides multiple benefits – saving natural resources, reducing supply risk and enhancing environmental performance. Therefore, in terms of their possible use as a cheap and available source of Li (and other valuable elements), the review paper evaluates various mining, industrial and mineral-processing wastes – waste aluminosilicates (including B clays), bauxite processing residues (including red mud or overhaul slag), coal gangue and coal ash, Sn-W clay residues and other wastes (e. g., rare earth molten salt electrolysis slag). The paper discusses physical, chemical and biotechnological methods used for Li extraction from these materials and documents that efficient extraction is technically feasible. To enhance the economic viability, co-extraction of Li and other critical elements (REE, Al, Rb, Cs, Ge, Ga, V, etc.) is evaluated as well. In addition to technologic and economic implications, overall framing of Li extraction from secondary sources in the context of environmental and social sustainability is discussed as well. 1. Introduction As traditional combustion of fossil fuels is in many aspects environmentally unsustainable and unfriendly (global warming, greenhouse gas production, local weather variation, toxic emissions, etc.) (Ahmad et al., 2022; Kazmi et al., 2023; Růˇ ziˇ ckov´ a et al., 2018; Wiero´ nska-Wi´ sniewska et al., 2022), cleaner energy production technologies are being developed and used. Since energy production should be not only ecologic but also economic, the application of the necessary multi-objective optimization on the electricity market leads to increased demand on energy storage sector (energy needs to be harvested when available and stored until needed) (Koohi-Fayegh and Rosen, 2020; Nassar et al., 2015; Růˇ ziˇ ckov´ a et al., 2019a, 2019b). Thus, due to worldwide shift to coal substituents (Raclavsk´ a et al., 2021, 2023; Tun et al., 2020) and decarbonization (Atabani et al., 2023; Coppola and Scala, 2021; Scala, 2016), global Li demand in 2021 and 2023 was 101 and 165 kt Li (International Energy Agency, 2024) representing a 63 % increase during these 2 years. And tremendous increase in Li consumption is also projected for foreseeable future – Li demand in 2050 is estimated to be about twice as high as in 2030 (International Energy Agency, 2024). Therefore it is not surprising that by far the most significant end-usage of Li in 2023 were batteries (87 % of Li consumption) with minor proportions related to ceramics and glass (4 %), lubricant greases (2 %), air treatment (1 %) and medical applications (1 %) (US Geological Survey, 2024); an increase in battery demand is expected to continue also in the future (International Energy Agency, 2021, 2023). As global Li reserves are limited, it is not sustainable to rely indefinitely on higher exploitation and mining (thereby threatening the resources of future generations). Instead, the focus should be paid on developing innovation and recycling technologies to ensure sustainable, secure and reliable supplies of this critical metal (Bielowicz, 2021; International Energy Agency, 2024; Mousa et al., 2022). Another urgent global concern is huge amount of wastes generated annually; it is generally accepted that recycling should be preferred to landfilling, stockpiling or other similar practices (Jedrusiak et al., 2023; Kucbel et al., 2019; Raclavsk´ a et al., 2018). Despite a long-term effort focused to reducing their amount, mining and mineral-processing wastes remain one of the world’s largest waste streams (Bian et al., 2012; Tiruta-Barna et al., 2007), around 2 trillion tonnes of tailings and waste rock is projected to be totally generated by mining by 2050 (Hudson-Edwards et al., 2024; Vivoda et al., 2025a). Proper management of these wastes provides multiple benefits – saving natural resources, reducing supply risk, and enhancing environmental * Corresponding author. Centre ENET, CEET, Vˇ SB – Technical University of Ostrava, 17. Listopadu 2172/15, 708 00, Ostrava-Poruba, Czech Republic. E-mail addresses: [email protected] (L. Bartoˇ nov´ a), [email protected] (H. Raclavsk´ a), [email protected] (B. ˇ Sv´ edov´ a). Contents lists available at ScienceDirect Resources Policy journal homepage: www.elsevier.com/locate/resourpol https://doi.org/10.1016/j.resourpol.2025.105790 Received 24 March 2025; Received in revised form 10 November 2025; Accepted 10 November 2025 Resources Policy 112 (2026) 105790 Available online 28 November 2025 0301-4207/© 2025 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license ( http://creativecommons.org/licenses/by/4.0/ ). performance. Therefore, the paper evaluates various mining, industrial and mineral-processing wastes in terms of their possible use as a source of Li (and other valuable elements). Section 2summarizes Li levels and Section 3deals with methods used for Li extraction from these materials. To enhance the economic viability, the possibility of co-extraction of Li and other critical elements is evaluated in Section 4. Based on the current knowledge gaps and limitations, suggestions for future research are proposed at the end of the paper. 2. Lithium concentrations in mining, industrial and processing wastes Due to its high reactivity, in nature, Li does not exist in metallic form but in salts and minerals dissolved in brines or present in rocks (Barbosa et al., 2023). Li is the 25th most abundant element in the Earth’s crust (Obut et al., 2022) – its levels in various rocks are in tens of ppm. Average Li concentration in Earth crust is 32 ppm (Yaroshevsky, 2006). Clarke value for Li in sedimentary rocks is 33 ppm (Ketris and Yudovich, 2009) and average Li abundance in shale was estimated to be 60 ppm (Moyle P R and Causey J D, 2001). Li average levels in ultrabasic, basic, intermediate and acid rocks are around 0.5, 15, 20, and 40 ppm Li (Yaroshevsky, 2006). There are numerous papers focused to elemental concentrations in various mining and mineral-processing wastes, but a suite of target elements does not always contain Li. Traditionally, the attention was preferably paid to more toxic and harmful elements due to environmental concerns or identification of polluting source; Li was often omitted also due to its low concentrations and low atomic number (Kantor et al., 2019; Li et al., 2016, 2016v´ edov´ a et al., 2019). And if the rare and critical elements are evaluated in various wastes, the attention is focused primarily to REE elements (Bartoˇ nov´ a et al., 2018; Santos et al., 2022; Wagner and Matiane, 2018). Regarding the hard rock ores, Li is traditionally extracted from pegmatites (complex aluminosilicate deposits containing quartz, feldspar, spodumene or mica minerals) (Tadesse et al., 2019). Nevertheless, spodumene and micaceous tailings as well as other wates originating from clay manufacturing still contain quite high Li levels, which is shown in Fig. 1. For rough estimate and evaluation, Li cut-off grades for pegmatites/clays are shown in the last 5 columns. Even if these values can be used only for rough evaluation, it indicates that there are certain tailings and wastes with comparable concentrations (1 micaceous tailing, 1 lepidolite processing waste and 1 lithium porcelain stone even clearly exceed these values) (Kuang et al., 2015; Siame and Pascoe, 2011). Moreover, mining cut-off grades include the cost of mining while waste materials are generally easily available. Li concentrations in bauxite processing residues (e.g., red mud or overhaul slag) are depicted in Fig. 2. Cut-off grade values related to independent recovery of Li are rather high (2323 or 3252 ppm Li) (Wang et al., 2013); however, in case of comprehensive utilization of these wastes where Li is extracted along with other valuable components, the cut-off grade values are much lower – 232 and 372 ppm Li (Wang et al., 2013). Then these values are comparable with bauxite mine tailings values (Tang et al., 2022; Wang et al., 2013, 2020; Zhang et al., 2021). Extremely high value (1.96 % Li) in waste Al electrolyte relates to dried and powdered sample (Tang et al., 2023) – it considerably exceeds even the cut-off grade for independent extraction of Li. Very high Li concentrations were published also for overhaul slags (Dong et al., 2024a, 2024b) or electrolytic Al slag (Cui et al., 2024). There has been an exponential growth in coal-related critical elements research, with Li being an obvious example (Spears, 2025). Even if renewable energy sources are becoming increasingly important in global energy mix, there are still certain other industrial sectors where coal remains an important feedstock (Kucbel et al., 2024). During coal mining and preparation, huge amount of discard coal products are generated; therefore, there is a need to consider coal discards as a vital source of energy or critical elements (H. Chen et al., 2022; Wagner, 2008). Fig. 3 summarizes Li concentrations in coals, coal gangues and coal ashes (including cut-off grades) showing increasing Li abundances in these 3 types of materials generally in the order: Li in coal <Li in coal gangue <Li in coal ash. This is in line with modes of occurrence of Li in most coals – Li is associated predominantly with mineral matter – namely the clays (e.g., adsorbed on kaolinite, chlorite and illite or present in cookerite) (Dai et al., 2012; D. Han et al., 2024; Spears, 2017; Yuan et al., 2024; Zhang et al., 2021; Zuo et al., 2022), organic association is much less Nomenclature LOI - Loss on ignition FA –Fly Ash EMH –European Metals Holding REE –Rare Earth Elements XRF –X-ray Fluorescence DMSO - Dimethyl Sulfoxide Fig. 1. Li concentrations in waste aluminosilicates ( a Castor and Henry, 2020; b Ertan, 2023; c Ertan, 2020; d Iqbal, 2015; e Kuang et al., 2015; f Maulidia et al., 2023; g Moyle P R and Causey J D, 2001; h Obut et al., 2022; i Ozbas R and Derum E M, 2021; j Roy et al., 2022; k Siame and Pascoe, 2011; l Sterba et al., 2019; m Wærsted et al., 2023; n Wang et al., 2020; o Yusupov et al., 2015). L. Bartoˇ nov´ a et al. Resources Policy 112 (2026) 105790 2 represented (D. Han et al., 2024; Sun et al., 2013). Six-step chemical extraction of coal gangue led to the conclusion of 85.56 % Li in an aluminosilicate form with a small fraction in sulfidic form (Dai et al., 2023). This is in line with the Tessier’s sequential extraction procedure that revealed 90.74 % Li in residual (aluminosilicate) form with 6.83 % in Fe-Mn oxides (H. Chen et al., 2022) and quite low Pearson’s correlation coefficients between Li and macerals calculated for No. 6 coal seam Soutpansberg Coalfield in South Africa (Li-Vit =0.36, Li-Int = 0.36, Li-Lip =0.41; while Li-Al =0.68) (Biswas et al., 2024). Predominant aluminosilicate Li association revealed also in case of intruded coals collected from both sides of a dolerite dyke (No. 2 Seam of the Witbank Coalfield, South Africa) (Moroeng et al., 2024). In coal fly ash, Li is mainly associated with non-magnetic fraction - aluminosilicates or glass fraction (Cao et al., 2024). Therefore, in general, the lowest Li concentrations in coals can be attributed to the highest content of organic matter (that is generally depleted in Li). Coal gangue generally contain up to 25 % of organic matter (Gao et al., 2021) and unburned carbon levels in coal ashes are in most power stations even lower (Bartoˇ nov´ a, 2015). There are also differences between minimum coal mining (and economic) grades of 80 (120) ppm Li proposed by (Sun et al., 2012) and Li cut-off grade for coal-bearing sequences related to ash basis (372 ppm Li) published by (Zou et al., 2023). Fig. 3 indicates that Li concentrations in most coal ashes are comparable with Zou’s cut-off grade (the last column) related to coal ash basis (372 ppm Li) whereas Li levels in coal gangues are similar as cut-off grade value for coal by (Sun et al., 2012) – 80(120) ppm; nevertheless, their ash content is higher than that of coal. Extremely high Li concentration (550 ppm Li) relates to Li-rich coal residue with high ash content (79.22 %) and low calorific value (Xie et al., 2023). Very high Li levels - 437.43 (Zhang et al., 2022) and 421.5 ppm Li (H. Chen et al., 2022) - were published for coal gangues from coal preparation plants in Inner Mongolia, China with 29.61 and 28.4 % LOI. In the latter study, Li concentrations was further increased when using Fig. 2. Li concentrations in bauxite and red mud residues ( a Cui et al., 2024; b Dong et al., 2024a; c Dong et al., 2024b; d Gu et al., 2018; e Gu et al., 2020b; f Tang et al., 2022; g Tang et al., 2023; h Wang et al., 2013; i Wu et al., 2023; j Zhang et al., 2021). Fig. 3. Li concentrations in coal, gangue and ash ( a H. Chen et al., 2022; b Dai et al., 2010; c Dai et al., 2023; d Gao et al., 2024; e Gong et al., 2016; f Hu et al., 2018; g C. Li et al., 2023; h J. Li et al., 2023; i Li et al., 2017; j Rezaei et al., 2023; k Saikia et al., 2015; l Sun et al., 2010; m Sun et al., 2012; n Xie et al., 2023; o Xing et al., 2024; p Xu et al., 2022; q Yang et al., 2014; r Yudovich and Ketris, 2015; s Zhang et al., 2022; t Zhou et al., 2022; u Zou et al., 2023). L. Bartoˇ nov´ a et al. Resources Policy 112 (2026) 105790 3 2.4–2.6 g/cm 3 density fraction or >0.25 mm size fraction – in both cases the Li levels exceeded 500 ppm Li (H. Chen et al., 2022). Detailed study of Li in semi-anthracite Qinshui Basin (Gaoping mine) reported average Li content in no. 15 coal as 66.59 ppm, but extremely high Li levels were observed in the coal parting (566 ppm) and floor (396 ppm) (P. Han et al., 2024), which is in line with observation of Hou et al. (2022); Hou et al. (2022) concluding that the dominant source of Li in coal (gangue) is not organic matter but minerals (namely aluminosilicates). In case of coal fly ash, the two finest particle-size fractions provided the highest Li concentrations (with enrichment factors 1.15–1.20) as well as the two lightest density fractions (with enrichment factors 1.20–1.26) (C. Li et al., 2023). As shown in Fig. 3, the highest Li concentration in coal FA (930 ppm Li) was published for PCC power plant Shuozhou, China (Li et al., 2017). This value is even 3-fold higher than 372 ppm Li cut-off grade (Zou et al., 2023). Nevertheless, some caution is needed due to U and Th present in coal/ashes (Parzentny and R´ og, 2019), average world coal levels of Th and U are 3.2 and 1.9 ppm Li (Parzentny and R´ og, 2019; Yudovich and Ketris, 2015). Fig. 4 summarizes the concentrations of Li in Sn-W clay residues and other tailings (Au or Mo-ore tailings). Upgraded mineral resource estimate by EMH (2021) for resources in the Cínovec deposit (Czech Republic) provided the cut-off grade of 0.1 % Li (0.22 % Li 2 O) (European Metals Holding Limited, 2021). Fig. 4 shows that Au wastes or tailings exhibit quite low Li levels as well as Mo-ore or phosphate wastes (Kumkrong et al., 2022; Moyle P R and Causey J D, 2001; Tavakoli Mohammadi et al., 2015; Yurkevich et al., 2023). In contrast, most Sn-W/zinnwaldite wastes (Jandov´ a et al., 2009; Kumar et al., 2023; H. Li et al., 2022; Samkov´ a, 2009) clearly exceed the cut-off grade value (European Metals Holding Limited, 2021). Absolutely the highest Li concentrations relate to the rare earth molten-salt electrolysis slag - 1.64, 1.79 and 2.29 % Li (Hu and Wang, 2021; X. Li et al., 2024; Tong et al., 2023), which is a waste material containing also high concentrations of other valuable elements (e.g. REE) (Yang et al., 2024). Overall comparison of Li levels in secondary sources according to their industrial origin (Figs. 1–4) documents that Li concentrations are in the range of several orders of magnitude. Despite the differences in individual samples, certain general trends can be inferred. The lowest Li levels are in the coal gangue and coal ash samples – generally within the range of 100–500 ppm Li (H. Chen et al., 2022; Dai et al., 2023, 2010; Yang et al., 2014); higher values - 900 ppm - are rather the exception (Li et al., 2017). Li levels in aluminosilicate-processing residues are around one order of magnitude higher (ca. 4000–5000 ppm) – e.g. in micaceous tailings (Siame and Pascoe, 2011), lepidolite-processing residues (Kuang et al., 2015) or in Li-porcelain stone (Wang et al., 2020); zinnwaldite-bearing wastes contain around 2000–3000 ppm Li (Jandov´ a et al., 2009; H. Li et al., 2022; Samkov´ a, 2009). Extremely high Li concentrations were observed in waste sources originated from two industrial branches – from Al extraction from bauxite and from REE production. Electrolytic Al slag/overhaul slag can contain up to 14 000–16 000 ppm Li (1.6 % Li) (Cui et al., 2024; Dong et al., 2024b); waste aluminium electrolyte in dried form contained nearly 20 000 ppm Li (2 % Li) (Tang et al., 2023). A rich source of Li is also REMSES (rare earth molten-salt electrolysis slag) containing around 16 000–23 000 ppm Li (1.6–2.3 % Li) (Hu and Wang, 2021; X. Li et al., 2024). Such Li levels (ca. 1–2 % Li) are comparable with Li concentrations in certain traditional Li ores, such as lepidolite (with common Li levels 1.5–2.5 % Li) (Mertineit and Schramm, 2019; Tian-ming et al.; Timich et al., 2023) documenting that Li extraction from mining and minerals processing wastes is undoubtedly worth further research. Nevertheless, Li recovery potential depends not only on the Li concentration but also on its mineral association and how easily it can be mobilized. For example, waste brines are advantageous as they contain Li in dissolved form (there is no need to roast them and/or leach Li by aggressive chemicals) – which is environmentally and economically beneficial. Even though tailings generally require roasting and/or leaching, their advantage is their fine-grained structure; therefore, the expenses for grinding, milling and similar practices are much lower than in case of coarse-grained slags or gangues. And general advantage of all these secondary sources (in comparison of traditional Li ores) is that Fig. 4. Li concentrations in Sn-W clay residues and other mining wastes ( a European Metals Holding Limited, 2021; b Franzaring et al., 2018; c Hu and Wang, 2021; d Huang et al., 2020; e Jandov´ a et al., 2009; f Kumar et al., 2023; g Kumkrong et al., 2022; h Li et al., 2022; i X. Li et al., 2024; j Mamani et al., 2020; k Martin et al., 2017; l Moyle P R and Causey J D, 2001; m Samkov´ a, 2009; n Shuiping et al., 2024; o Shumilova et al., 2022; p Tavakoli Mohammadi et al., 2015; q Tong et al., 2023; r Yurkevich et al., 2023). L. Bartoˇ nov´ a et al. Resources Policy 112 (2026) 105790 4 they are easily available without mining. 3. Methods Numerous physical and chemical methods are used for Li recovery from mining and mineral-processing wastes; generally, physical separation methods are used for the preparation of the concentrate where Li levels can be further enriched (or directly extracted out of it) by other methods, such as roasting and/or leaching (Fig. 5). It was shown that optimized milling/disintegration of the sample prior to application of physical or chemical methods can significantly enhance the extraction efficiency (Urakaev et al., 2020). Due to great variability of matrixes in mining and mineral processing wastes, detailed description of individual extraction schemes is discussed separately according to origin of waste source in sections: 3.1. Aluminosilicates, 3.2. Bauxite processing residues, 3.3. Coal and coal gangue and 3.4. Zinnwaldite and other mining wastes. 3.1. Waste aluminosilicates Wastes from aluminosilicates processing can still contain quite high Li levels leading to testing of various procedures of Li extraction from these materials. Kaolin mining waste (Fig. 6A) was first pre-concentrated by flotation and high-intensity wet magnetic separation to increase the original Li 2 O concentration (0.84 % Li 2 O) to 2.07 %. This pre-concentrate was then roasted with CaSO 4 or Na 2 SO 4 leading to 84–97 % Li extraction (Siame and Pascoe, 2011). Comparison of Li extraction efficiency from spodumene after roasting at 1000 ◦C with Na 2 SO 4 , MgSO 4 .7H 2 O and CaSO 4 .2H 2 O revealed the best extraction efficiency in case of Na 2 SO 4 (93.8 % Li was converted into LiNaSO 4 ) (Qiu et al., 2023). Another successful procedure was applied to lepidolite processing gypsum residue (Fig. 6A) containing 0.95 % Li 2 O – after NaOH solution digestion (0.5–10 MPa) and filtration, Li 3 PO 4 was precipitated with 87.98 % yield (Kuang et al., 2015). In case of bauxitic claystone (Gu et al., 2020a), it was concluded that calcination could effectively increase the extraction efficiency; nevertheless, the calcination temperature should not be too high (calcination temperature exceeding 600 ◦C led to decreasing Li leachability). Boron clays wastes (Fig. 6B) are another promising source of Li. Common approach is based on roasting with various salts at 750–1000 ◦C followed by water leaching. The highest Li extraction (90.41 %) was obtained by CaCl 2 +NaCl roasting; high efficiencies was shown also for CaSO 4 .2H 2 O +CaCO 3 (88.16 %) and H 2 SO 4 (85.7 %) roasting (Büyükburç et al., 2006; Ertan, 2020; Obut et al., 2022). Roasting of B clays at 750–1000 ◦C is usually conducted only for 1 h but it still requires energy to heat the sample. In contrast, using bioleaching with Aspergillus niger for ca. 31 days does not require heating to high temperatures but it needs longer time period; Li extraction efficiency is then 78.67 % (Ertan, 2023) (Fig. 6B). In addition to traditional (physico)chemical extraction procedures, the promising potential of phytoremediation and phytostabilization of Li (and V and Cr) was documented by Elektorowicz and Keropian (2015). 3.2. Bauxite processing residues Neutralization of red mud (224 ppm Li) by 0.01M HCl or 0.5M oxalic acid followed by 25 % acetic acid leaching (Fig. 7) led to 58–60 % or 42–47 % Li leaching efficiency (Gu et al., 2020b). Higher leaching rates were achieved by means of mixed acid (H 2 SO 4 +H 3 PO 4 ) at 100 ◦C from bauxite mine tailings (0.2 and 0.21 % Li 2 O) – 96.6 and 96.35 % Li was leached (Wu et al., 2023; Zhang et al., 2021). Roasting with 98 % H 2 SO 4 at 300–375 ◦C in N 2 was used for dried aluminium cryolite electrolyte containing 1.96 % Li – Li recovery was 98.78 % (Dong et al., 2024a, 2024b, 2024c; Tang et al., 2023). In case of overhaul slags from Al industry, roasting with H 2 SO 4 or CaSO 4 at 360–750 ◦C followed by water leaching provided >95 % Li extraction efficiencies (Dong et al., 2024a, 2024b, 2024c). It can be hypothesized that (similarly as in case of coal and coal gangue (H. Chen et al., 2022; Qin et al., 2022)), roasting the sample supports the leaching efficiency; nevertheless, more research is needed to confirm/disprove this hypothesis due to rather different character of the original wastes. Nevertheless, quite low roasting temperature (300–750 ◦C (Dong et al., 2024a, 2024b, 2024c; Tang et al., 2023)) is similar as 600 ◦C used for coal (Zhang et al., 2020). Moreover, in addition to higher leaching efficiency and lower emissions, lower temperature of roasting is cheaper (than using temperatures exceeding e.g. 1000 ◦C). 3.3. Coal and coal gangue Coal gangue contains various proportions of organic fraction and mineral matter with quite low Li levels; therefore, preconcentration of Li by high-gradient magnetic separation helps to avoid consuming a lot of chemicals or energy for heating the whole material (Sun et al., 2024). Another practical pre-concentration techniques enabling removal of fractions depleted in Li are XRF sorting equipment in combination with vibrating feeder and electromagnetic impactor (Dai et al., 2023) or gravity separation (Yang et al., 2022). Methods of physical pre-concentration (particle-size separation, magnetic separation, density separation etc.) that can be used for FA samples prior to their leaching are discussed in detail in (Zhou et al., 2022). It was shown (H. Chen et al., 2022; Qin et al., 2022) that direct leaching of coal gangue (by 3M HCl or by NH 4 Cl/(NH 4 ) 2 SO 4 ) was rather Fig. 5. Pre-concentration and extraction methods for mining and mineral processing wastes. L. Bartoˇ nov´ a et al. Resources Policy 112 (2026) 105790 5 inefficient (Qin et al., 2022) with only <6 % Li leached (Fig. 8A). In contrast, roasting the gangue prior to leaching significantly increased the Li extraction efficiency (H. Chen et al., 2022; Kang et al., 2024; Qin et al., 2022) - Li extraction efficiency from coal gangue (421.5 ppm Li) after calcination at 600 ◦C and 3M HCl leaching (90 ◦C) reached 92.74 % (H. Chen et al., 2022). Roasting of coal gangue (107 ppm Li) with (NH 4 ) 2 SO 4 +NH 4 Cl at 400 ◦C followed by water leaching leached 80.83 % Li (Qin et al., 2022). It is interesting in this context that calcination/roasting temperature is not too high (400 and 600 ◦C) which is in line with the conclusion of Zhang et al. (2020); Zhang et al. (2020) that maximum Li extraction from coal was achieved after 600 ◦C calculation (further increase in calcination temperature decreased the Li extraction efficiency). After 1.2M HCl leaching, 70–80 % Li was extracted. Good Li extraction efficiency was observed also by (Zhang et al., 2023) after 400 ◦C roasting the coal gangue followed by leaching in 2M HCl (94 % Li extracted). 70 % H 2 SO 4 roasting at only 180 ◦C and water leaching extracted 84.42 % Li (Xie et al., 2024) (Fig. 8A). Another activation method (that can be applied on coal gangue prior to its thermal treatment) is mechanical activation (long grinding) (Guo et al., 2016; Wang et al., 2024). For example, milling coal FA with sodium pyrosulfate efficiently improved the Li extraction rate (Fang et al., 2023). In case of fly ash (FA), good results were achieved by sulphatising sintering (Fig. 8B) followed by acid leaching thereby extracting 95.6 % Li. Alkali leaching (followed by carbonation, evaporation and Li 2 CO 3 precipitation) provided 85.3 % Li leaching rate (Qin et al., 2015). Another study (Li et al., 2017) documented that the efficiency of 6M HCl leaching can be enhanced by pre-desilication of FA by NaOH solution at 120 ◦C; then 82.23 % Li was leached (Li et al., 2017). Comparison of various thermal activation additives led to the conclusion that Na 2 CO 3 provided better Li extraction efficiency than NaOH, NaCl, CaO, CaCO 3 , (NH 4 ) 2 SO 4 , CH 3 COONH 4 or NH 4 Cl; and, that leaching performance of citric acid was better than that of tartaric or lactic acid (C. Li et al., 2024). Good extraction efficiency (>88 % Li) after Na 2 CO 3 roasting at 800–850 ◦C was also achieved by (Gao et al., 2024; Rezaei et al., 2022, 2023). If 0.5M citric acid was used instead of 3M HCl, Li extraction efficiency decreased from 88-90 % to 70–80 %; nevertheless, 0.5M citric acid is less hazardous than 3M HCl (Gao et al., 2024). Organic acids are produced also during bioleaching – e.g. Pseudomonas putida produced 65.76 % gluconic acid, 11.66 % oxalic acid and 7.23 % citric acid (Rezaei et al., 2023). Bioleaching was successfully used to extract also other valuable elements from coal FA – hydrothermal treatment (NaOH, H 2 SO 4 , 150 ◦C, 0.476 MPa, 24 h) followed by Aspergillus niger bioleaching led to the extraction of 89.20 % Ti, 32.00 % Ga, 54.30 % Sr and 35.40 % Ba (but Li was not evaluated in this study) (Su et al., 2020). 3.4. Zinnwaldite and other mining wastes Procedures used for Li extraction from Ta-Nb tailings or zinnwalditecontaining wastes are depicted in Fig. 9 indicating that physical separation methods (e.g. magnetic separation) are commonly used for the pre-concentration of Li in Ta-Nb mine tailings (Huang et al., 2020) or zinnwaldite wastes (European Metals Holding Limited, 2021; Martin et al., 2017). While in case of Ta-Nb mine tailings (0.61 % Li 2 O) the non-magnetic residue (0.68 % Li 2 O) was used for further processing Fig. 6A. Procedures of Li extraction from waste aluminosilicates ( a Gu et al., 2020a; b Kuang et al., 2015; c Siame and Pascoe, 2011; d Wang et al., 2020). Fig. 6B. Procedures of Li extraction from B-clay wastes ( a Büyükburç et al., 2006; b Ertan, 2023; c Ertan, 2020; d Obut et al., 2022). L. Bartoˇ nov´ a et al. Resources Policy 112 (2026) 105790 6 (Huang et al., 2020, p. 20), Li enrichment in zinnwaldite-bearing waste is achieved by magnetic retention of zinnwaldite grains (zinnwaldite is paramagnetic) (Jandov´ a et al., 2010; Siame and Pascoe, 2011). Flotation is another promising approach for the preparation of Li-concentrate (Huang et al., 2020; Li et al., 2017). Current research (H. Li et al., 2022) documents that the flotation performance can be efficiently improved by previous microbial pre-treatment by silicate bacteria LM-1. Typical efficient processing of zinnwaldite concentrate includes CaSO 4 +Ca(OH) 2 or CaCO 3 sintering (825–950 ◦C) followed by water leaching (Jandov´ a et al., 2009, 2010; Vu et al., 2013). Numerous authors use calcareous additives (i.a.) due to the retention of F contained in zinnwaldite that is toxic and volatile and could be abundant in emissions; Ca-bearing additives bound F thereby forming CaF 2 . For example, 91.32 % Li extraction recovery was achieved by using CaO +B 2 O 3 with calcium - boron ratio of 3 based on both high extraction efficiency of Li (and Rb) and minimizing F emission originating from zinnwaldite at the same time. Sole B 2 O 3 provides even moderately higher Li recovery (than CaO-B 2 O 3 blend) but CaO is added to significantly reduce F emissions (forming CaF 2 ) (Shuiping et al., 2024). Another promising waste material containing high Li levels is rare earth molten salt electrolysis slag (with ca. 1–2 % Li) (Hu and Wang, 2021; X. Li et al., 2024; Tong et al., 2023). Even if the extraction procedures vary greatly, extraction efficiency is in all cases very high (>99 % Li leached) (Hu and Wang, 2021; X. Li et al., 2024; Tong et al., 2023). 3.5. Extraction methods comparison As shown in Fig. 6A and B, 7, 8A, 8B and 9, the most common extraction methods are acid and alkaline treatment, roasting with various salts and bioleaching, which is summarized in Table 1 along with major advantages and drawbacks of these procedures. Acid treatment is common in case of bauxite-processing residues (red mud, tailings etc.) where acetic acid and sulfuric acid (sometimes blended with phosphoric acid) provide good results. The temperatures are generally lower than in case of salt roasting which reduces energy costs. Acid method with H 2 SO 4 is widely used and is highly adaptable to variability of the composition of starting material (Cao et al., 2024; Tian-ming et al.; M. Yang et al., 2025); nevertheless, low selectivity may place greater demands on subsequent separation (Sarker et al., 2022). Alkaline treatment is less common in these materials; nevertheless, it was successfully used for Li extraction from lepidolite processing gypsum residue (Kuang et al., 2015) or for desilication of fly ash by NaOH (Li et al., 2017). Waste materials originating from clay minerals processing are generally treated by roasting with various salts, such as CaCO 3 , CaSO 4 , or Na 2 SO 4 that are often used in blends – Na 2 SO 4 +CaCl 2 (Wang et al., 2020) CaSO 4 +CaCO 3 (Büyükburç et al., 2006) or CaCl 2 +NaCl (Ertan, 2020). Roasting with salts is typically conducted at high temperatures 850–1050 ◦C, which can be somewhat costly. Na-salts are generally preferred to K ones as they are cheaper than their K counterparts. Roasting with calcareous salts (CaCO 3 , CaO, CaCl 2 or CaSO 4 ) provides good results also in case of zinnwaldite-originated wastes (Jandov´ a et al., 2010; Kristianov´ a et al., 2023; Vu et al., 2013). Bioleaching can be used either as a sole extraction method (Ertan, 2023) or in combination with salt sintering (Rezaei et al., 2023) which can further enhance the extraction efficiency. It is worth mentioning that in case of REMSES (containing extremely high Li levels of 1–2 %), high extraction efficiencies can be achieved by various procedures – by salt roasting with CaO +Al 2 (SO 4 ) 3 at 900 ◦C (Tong et al., 2023), by acid treatments (e.g. with HNO 3 at 250 ◦C (Hu and Wang, 2021)) and even by alkaline treatment (with CaO in hot water (X. Li et al., 2024)) – all these procedures provided >96 % extraction efficiency for Li. Regardless of the preferred extraction method, using some preFig. 7. Procedures of Li extraction from bauxite processing residues ( a Cui et al., 2024; b Dong et al., 2024a; c Dong et al., 2024b; d Dong et al., 2024c; e Gu et al., 2020a; f Tang et al., 2023; g Wu et al., 2023; h Zhang et al., 2021). L. Bartoˇ nov´ a et al. Resources Policy 112 (2026) 105790 7 concentration or activation procedure is generally recommended to further enhance the extraction efficiency (Akhmadiyeva et al., 2025; Bartoˇ nov´ a et al., 2025; Urakaev et al., 2020). 4. Joint extraction of Li and other elements As reviewed in Section 2, Li concentrations in mining and mineralprocessing wastes are generally too low to be economically viable to extract Li as the only element. For design of a full (or at least multicomponent) utilization of given material, knowledge of other elements extractability is crucial – the most interesting literature findings in this area are discussed below. 4.1. Joint extraction of Li and Rb (or Cs) Since Rb and Cs belong to alkaline metals as well, their modes of occurrence and/or leaching behaviour are in many aspects similar to Li. Literature results of co-extraction of Li and Rb (or other elements) are summarized in Table 2. In case of zinnwaldite-originating wastes and traditional procedures – good extraction rates were achieved not only for Li (77–91 %) but also for Rb where extraction percentages were even higher (90–93 %) (Jandov´ a et al., 2010; Kristianov´ a et al., 2023; Shuiping et al., 2024; Vu et al., 2013). Even higher recovery of both elements (98.7 % Li and 97.27 % Rb) was achieved by roasting lithium porcelain stone with Na 2 SO 4 and CaCl 2 at 850 ◦C followed by water leching (Wang et al., 2020). Alternative approach based on bioleaching was tested as well – using either silicate bacteria LM-1 (H. Li et al., 2022) or Aspergillus niger (Ertan, 2023); extraction efficiency is then somewhat lower (71.68 or 78.67 % Li and 80.42 or 37.44 % Rb) and the time needed for such procedure is generally higher – e.g. 31 days (Ertan, 2023); nevertheless, there is no need to heat the material to high temperatures (energy savings) or to use dangerous chemicals. 4.2. Joint extraction of Li and Al (or other elements) Joint extraction of Li and Al is typical for Al-containing wastes, such as bauxite-processing wastes (Han et al., 2021; Tang et al., 2023; Zhang et al., 2021) or coal gangue/ash (Li et al., 2017; Qin et al., 2022; Shao et al., 2022; Zhang and Honaker, 2020), as shown in Table 3. Using sulfuric acid/sulfate salts (Dong et al., 2024a; Qin et al., 2022; Tang et al., 2023; Zhang et al., 2021), NaOH (Kuang et al., 2015; C. Li et al., 2024) or even calcination without additives (H. Chen et al., 2022; Shao et al., 2022; Zhang and Honaker, 2020) are the most commonly used approaches providing good Li extraction efficiency. Aluminium extraction rate is generally somewhat lower 30–89 % (C. Li et al., 2024; Qin et al., 2022; Tang et al., 2023; Zhang and Honaker, 2020; Zhang et al., 2021); however, roasting the coal gangue without additives followed by nitric acid leaching provided 95.2 % Al recovery, which was even higher than that of Li (80.5 %) (Shao et al., 2022). Very high Al Fig. 8A. Procedures of Li extraction from coal gangue and coal ( a H. Chen et al., 2022; b Qin et al., 2022; c Xie et al., 2023; d Xie et al., 2024; e Zhang et al., 2023; f Zhang et al., 2020). Conversion note: 1 ppm =10−4 %. L. Bartoˇ nov´ a et al. Resources Policy 112 (2026) 105790 8 extraction rate (nearly 100 %) was achieved by NaOH digestion at 136 ◦C from Li-extraction gypsum residue originating from lepidolite processing where Li extraction rate was 96.4 % (Kuang et al., 2015). To avoid heating the sample to high temperatures, extraction of Li from coal gangue by intercalation was studied as well– the tested coal gangue was intercalated by DMSO at 60 ◦C followed by 3M HCl leaching at 90 ◦C; extraction rates were somewhat lower (17.55 % Li and 10.55 % Al), but the main advantage of this approach is energy saving and reducing emissions during calcination (H. Chen et al., 2022). If higher extraction rates are preferred, traditional approach (calcination followed by acid leaching) applied on the same material led to 94.44 % Li and 65.69 % Al recovery (H. Chen et al., 2022). 4.3. Joint extraction of Li and Ga, Ge or REE (and other elements) The waste materials frequently studied in terms of Li-Ga-Ge joint extraction are coal gangues and coal slags or fly ashes; if emphasis is based on joint extraction of Li and REE (or F), then rare earth electrolytic molten salt slag is a promising waste material – the most interesting results in this research field are summarized in Table 4. If coal gangue, slag or fly ash samples were studied as a source of Li and Ga or Ge, Na 2 CO 3 roasting at 800–875 ◦C followed by acid leaching is one of the most common procedure (Gao et al., 2024; C. Li et al., 2024; Rezaei et al., 2023, 2022) providing >90 % Li and Ga and moderately lower extraction of Ge. Low roasting temperatures 300–400 ◦C (energy saving) were tested with KOH, NaOH or H 2 O 2 additives - if followed by water leaching at 30 ◦C, 28–41 % Li and 36–52 % Ga were extracted (Pan et al., 2024). Calcination without additive at 600–750 ◦C (followed by 1.2M HCl leaching) led to good extraction rates of Li, REE, P, Sr or Mg (Zhang and Honaker, 2020). Rare earth molten salt electrolytic slag originates from electrolytic precipitation of rare earth metals from the melt of their salts, and it can be used as a promising source of numerous valuable elements. The results listed in Table 4 suggest that regardless of the procedure used, good extraction rates can be achieved for Li (>96 %) and REE (>90 %) (X. Li et al., 2024; Tong et al., 2023; Yang et al., 2024). Useful information and suggestions for further research can be inferred from sequential extraction studies applied on such waste materials. Tessier’s sequential extraction procedure applied on 3 red mud samples (Gu et al., 2018) revealed similar distribution of Li, Sc, Y and La-Lu – dominant dissolution in NH 2 OH.HCl in 25 % CH 3 COOH, which is generally attributed to Fe-Mn oxides association. Minor percentages of these elements were dissolved in CH 3 COONa/CH 3 COOH at pH =5 (which is used for dissolution of carbonates) or in HNO 3 /H 2 O 2 at pH =2 (85 ◦C), which is generally used for organic matter association. In contrast, Ga was prevalently dissolved by water or by HNO 3 /H 2 O 2 , which corresponds with dominant water-leachable fraction and minor organic matter bound species. Nb was predominantly dissolved by HNO 3 /H 2 O 2 (Gu et al., 2018). Information on distribution of valuable elements among individual fractions during minerals/ores processing and separation is important as well (and can be used for designing the optimal procedure for the extraction of these elements or for selecting optimal waste as a feedstock). For example, in case of alumina production from bauxite (Bayer process), after separation of red mud and Na aluminate solution, Sc and Ti were enriched in red mud (54–120 ppm and 0.98–5.34 %) while Ga and Li enter sodium aluminate liquor (60–120 ppm Ga and 1.5–4.9 % Li) (Y. Chen et al., 2022). During the utilization of feldspar processing waste, mica containing light fraction can be used as a source of Li Fig. 8B. Procedures of Li extraction from fly ash ( a Fang et al., 2023; b Gao et al., 2024; c C. Li et al., 2024; d Li et al., 2017; e Qin et al., 2015; f Rezaei et al., 2023; g Rezaei et al., 2022; h Xing et al., 2024; i Xu et al., 2021). Conversion note: 1 ppm =10−4 %. L. Bartoˇ nov´ a et al. Resources Policy 112 (2026) 105790 9 spent coffee ground valorization for fuel pellet production in a biorefinery. Environ. Dev. Sustain. 25, 7585–7623. https://doi.org/10.1007/s10668-022-02361-z. Attílio, L.A., 2025. Impact of critical mineral prices on energy transition. Appl. Energy 377, 124688. https://doi.org/10.1016/j.apenergy.2024.124688. Barbosa, H., Soares, A.M.V.M., Pereira, E., Freitas, R., 2023. Lithium: a review on concentrations and impacts in marine and coastal systems. Sci. Total Environ. 857, 159374. https://doi.org/10.1016/j.scitotenv.2022.159374. Bartoˇ nov´ a, L., 2015. Unburned carbon from coal combustion ash: an overview. Fuel Process. Technol. 134, 136–158. https://doi.org/10.1016/j.fuproc.2015.01.028. Bartoˇ nov´ a, L., Kov´ ar, F., Kucbel, M., 2025. Magnetic separation of ash and slag residues for their multi-component utilization: an overview. Int. J. Coal Sci. Technol. 12, 78. https://doi.org/10.1007/s40789-025-00814-0. Bartoˇ nov´ a, L., Raclavsk´ a, H., 2022. Behavior of Cr during coal combustion: an overview. Fuel 322, 124210. https://doi.org/10.1016/j.fuel.2022.124210. Bartoˇ nov´ a, L., Raclavsk´ a, H., ˇ Cech, B., Kucbel, M., 2020. Behavior of Cd during coal combustion: an overview. Processes 8, 1237. https://doi.org/10.3390/pr8101237. Bartoˇ nov´ a, L., Raclavsk´ a, H., Najser, J., 2023. Vanadium – valuable and toxic element in coal combustion ash: an overview. Process Saf. Environ. Prot. 172, 923–940. https:// doi.org/10.1016/j.psep.2023.02.070. Bartoˇ nov´ a, L., Serenˇ cíˇ sov´ a, J., ˇ Cech, B., 2018. Yttrium partitioning and associations in coal-combustion ashes prior to and after their leaching in HCl. Fuel Process. Technol. 173, 205–215. https://doi.org/10.1016/j.fuproc.2018.01.011. Bas¸türkcü, H., 2021. Investigation of dissolution behavior of scandium and lithium from red mud. Bull. Miner. Res. Explor. 1–10. https://doi.org/10.19111/ bulletinofmre.941073. Bian, Z., Miao, X., Lei, S., Chen, S., Wang, W., Struthers, S., 2012. The challenges of reusing mining and mineral-processing wastes. Science 337, 702–703. https://doi. org/10.1126/science.1224757. Bielowicz, B., 2021. Selected critical raw materials in waste from coal gasification in Poland. Energies 14, 8071. https://doi.org/10.3390/en14238071. Biswas, S., Moroeng, O.M., Wagner, N.J., 2024. Mineralogy and geochemical controls on the distribution of REY-Ga-Se-Nb enrichment in the no. 6 coal seam, Soutpansberg Coalfield, South Africa. Ore Geol. Rev., 106310 https://doi.org/10.1016/j. oregeorev.2024.106310. Boroumand, Y., Razmjou, A., 2024. Adsorption-type aluminium-based direct lithium extraction: the effect of heat, salinity and lithium content. Desalination 577, 117406. https://doi.org/10.1016/j.desal.2024.117406. Botelho Junior, A.B., 2025. Sustainable mining – unlocking resources towards circular economy to meet energy transition through electrochemistry. J. Environ. Chem. Eng. 13, 116600. https://doi.org/10.1016/j.jece.2025.116600. Büyükburç, A., Maras ¸lıo˘ glu, D., Bilici, M.S.U., K¨ oksal, G., 2006. Extraction of lithium from boron clays by using natural and waste mate rials and statistical modelling to achieve cost reduction. Miner. Eng. 19, 515–517. https://doi.org/10.1016/j. mineng.2005.11.003. Cao, Y., Zhou, C., Gao, F., Huang, Y., Zhu, W., Liu, G., Wang, J., 2024. Lithium recovery from typical coal-based solid wastes: critical technologies, challenges, and prospects. Chem. Eng. J. 498, 155121. https://doi.org/10.1016/j.cej.2024.155121. Castor, S.B., Henry, C.D., 2020. Lithium-rich claystone in the McDermitt Caldera, Nevada, USA: Geologic, mineralogical, and geochemical characteristics and possible origin. Minerals 10, 68. https://doi.org/10.3390/min10010068. Chen, H., Zhang, L., Pan, J., Long, X., He, X., Zhou, C., 2022a. Study on modes of occurrence and enhanced leaching of critical metals (lithium, niobium, and rare earth elements) in coal gangue. J. Environ. Chem. Eng. 10, 108818. https://doi.org/ 10.1016/j.jece.2022.108818. Chen, L., Chen, W., Chen, P., Zhang, D., Liu, W., 2025. Selective extraction of lithium and REEs from waste rare earth polishing powder: a two-stage leaching technique. Sep. Purif. Technol. 353, 128524. https://doi.org/10.1016/j.seppur.2024.128524. Chen, Y., Zhang, T., Lv, G., Chao, X., Yang, X., 2022b. Extraction and utilization of valuable elements from bauxite and bauxite residue: a review. Bull. Environ. Contam. Toxicol. 109, 228–237. https://doi.org/10.1007/s00128-022-03502-w. Coppola, A., Scala, F., 2021. Chemical looping for combustion of solid biomass: a review. Energy Fuels 35, 19248–19265. https://doi.org/10.1021/acs.energyfuels.1c02600. Cui, L., Wang, W., Chao, X., Gao, J., Cheng, F., 2024. Efficient lithium recovery from electrolytic aluminum slag via an environmentally friendly process: leaching behavior and mechanism. J. Clean. Prod. 439, 140800. https://doi.org/10.1016/j. jclepro.2024.140800. Dai, S., Jiang, Y., Ward, C.R., Gu, L., Seredin, V.V., Liu, H., Zhou, D., Wang, X., Sun, Y., Zou, J., Ren, D., 2012. Mineralogical and geochemical compositions of the coal in the Guanbanwusu Mine, Inner Mongolia, China: further evidence for the existence of an Al (Ga and REE) ore deposit in the Jungar Coalfield. Int. J. Coal Geol. 98, 10–40. https://doi.org/10.1016/j.coal.2012.03.003. Dai, S., Sun, F., Wang, Lei, Wang, Lanhao, Zhang, R., Guo, H., Xing, Y., Gui, X., 2023. A new method for pre-enrichment of gallium and lithium based on mode of occurrence in coal gangue from Antaibao surface mine, Shanxi Province, China. J. Clean. Prod. 425, 138968. https://doi.org/10.1016/j.jclepro.2023.138968. Dai, S., Zhao, L., Peng, S., Chou, C.-L., Wang, X., Zhang, Y., Li, D., Sun, Y., 2010. Abundances and distribution of minerals and elements in high-alumina coal fly ash from the Jungar power plant, Inner Mongolia, China. Int. J. Coal Geol. 81, 320–332. https://doi.org/10.1016/j.coal.2009.03.005. Dong, L., Jiao, F., Liu, W., Wang, C., Wang, D., Qin, W., 2024a. A novel approach for extracting lithium from overhaul slag by low temperature roasting – water leaching. Chem. Eng. J. 481, 148571. https://doi.org/10.1016/j.cej.2024.148571. Dong, L., Jiao, F., Liu, W., Wang, C., Wang, D., Qin, W., 2024b. Selective extraction of lithium and solidified fluoride from overhaul slag by the calcium sulfate roasting and water leaching. Miner. Eng. 217, 108943. https://doi.org/10.1016/j. mineng.2024.108943. Dong, L., Jiao, F., Liu, W., Wang, D., Chen, Wang, Qin, W., 2024c. Selective preparation of lithium carbonate from overhaul slag by high temperature sulfuric acid roasting – water leaching. J. Environ. Manag. 359, 120963. https://doi.org/10.1016/j. jenvman.2024.120963. Dong, L., Jiao, F., Liu, W., Zhang, Z., Qin, W., 2025. Separation of aluminum and lithium in sulfuric acid roasting leachate of overhaul slag by Di-(2-ethylhexyl) phosphoric acid extraction and sulfuric acid stripping. Hydrometallurgy 236, 106521. https:// doi.org/10.1016/j.hydromet.2025.106521. Elektorowicz, M., Keropian, Z., 2015. Lithium, vanadium and chromium uptake ability of Brassica juncea from lithium mine tailings. Int. J. Phytoremediation 17, 521–528. https://doi.org/10.1080/15226514.2013.876966. Ertan, B., 2023. Extraction of high-value metals from boron waste by bioleaching using Aspergillus niger. Trans. Indian Inst. Met. 76, 3137–3145. https://doi.org/10.1007/ s12666-023-03013-0. Ertan, B., 2020. Chlorination roasting process for extraction of valuable metals in boron clays. Pamukkale Univ. J. Eng. Sci. 26, 1267–1272. https://doi.org/10.5505/ pajes.2019.90836. Estay, H., Troncoso, E., 2025. LiOH production and Mg removal from Li-chloride brines and waste: a membrane-integrated approach for next-generation circular hydrometallurgy. J. Sustain. Metall. https://doi.org/10.1007/s40831-025-01220-1. European Metals Holding Limited, 2021. Resource Upgrade at Cínovec Lithium Project to 708Mt Including 53.5Mt of New Measured Resource. Fang, D., Xia, Y., Li, Y., Xing, Y., Miao, Z., Gui, X., 2024. Separation and recovery of valuable carbon components and Li/Ga metals in coal gangue by using a flotation flowsheet. ACS Omega 9, 14336–14342. https://doi.org/10.1021/ acsomega.3c10335. Fang, H., Zhou, C., Xu, S., Shi, J., Hu, Y., Liu, G., 2023. High-efficiency extraction of aluminum and lithium from coal fly ash using a novel sodium pyrosulfate mechanochemical activation - sodium persulfate pressure leaching technology. J. Clean. Prod. 423, 138841. https://doi.org/10.1016/j.jclepro.2023.138841. Franzaring, J., Damsohn, W., Fangmeier, A., Schlosser, S., Kurz, H., Büttner, P., 2018. Phytotoxicity of tin mine waste and accumulation of involved heavy metals in common buckwheat (Fagopyrum esculentum Moench). Int. J. Phytoremediation 20, 462–470. https://doi.org/10.1080/15226514.2017.1365349. Gao, R., Peng, H., He, Q., Meng, Z., Xiang, P., Hou, L., Miao, Z., 2024. Simultaneous leaching of Li, Ga, and REEs from coal fly ash and a novel method for selective leaching of Li and Ga. J. Environ. Chem. Eng. 12, 112022. https://doi.org/10.1016/ j.jece.2024.112022. Gao, S., Zhang, S., Guo, L., 2021. Application of coal gangue as a coarse aggregate in green concrete production: a review. Materials 14, 6803. https://doi.org/10.3390/ ma14226803. Gong, B., Tian, C., Xiong, Z., Zhao, Y., Zhang, J., 2016. Mineral changes and trace element releases during extraction of alumina from high aluminum fly ash in Inner Mongolia, China. Int. J. Coal Geol. 166, 96–107. https://doi.org/10.1016/j. coal.2016.07.001. Gu, H., Guo, T., Wen, H., Luo, C., Cui, Y., Du, S., Wang, N., 2020a. Leaching efficiency of sulfuric acid on selective lithium leachability from bauxitic claystone. Miner. Eng. 145, 106076. https://doi.org/10.1016/j.mineng.2019.106076. Gu, H., Li, W., Li, Z., Guo, T., Wen, H., Wang, N., 2020b. Leaching behavior of lithium from bauxite residue using acetic acid. Min. Metall. Explor. 37, 443–451. https:// doi.org/10.1007/s42461-020-00181-1. Gu, H., Wang, N., Hargreaves, J.S.J., 2018. Sequential extraction of valuable trace elements from bayer process-derived waste red mud samples. J. Sustain. Metall. 4, 147–154. https://doi.org/10.1007/s40831-018-0164-6. Guo, Y., Yan, K., Cui, L., Cheng, F., 2016. Improved extraction of alumina from coal gangue by surface mechanically grinding modification. Powder Technol. 302, 33–41. https://doi.org/10.1016/j.powtec.2016.08.034. Guo, Z.-Y., Wang, J., Zhang, P., Wang, L., Lai, Z., Ji, Z.-Y., 2025. Lithium selective membranes for direct lithium extraction from complex brine. Prog. Mater. Sci. 156, 101582. https://doi.org/10.1016/j.pmatsci.2025.101582. Han, D., Peng, Z., Song, E., Shen, L., 2021. Leaching behavior of lithium-bearing bauxite with high-temperature bayer digestion process in K 2 O-Al 2 O 3 -H 2 O system. Metals 11, 1148. https://doi.org/10.3390/met11071148. Han, D., Shen, L., Song, E., Peng, Z., 2024a. Leaching behaviors of lithium-rich bauxite flotation tailings in sodium bicarbonate solution. J. Sustain. Metall. 10, 241–249. https://doi.org/10.1007/s40831-024-00787-5. Han, P., Zhao, F., Liu, D., Zhang, Qi, Zhang, Qinqin, Ullah, S., 2024b. Occurrence and favorable enrichment environment of lithium 2 in gaoping coal measures: evidence from mineralogy and geochemistry. Appl. Sci. 14 (16), 7298. https://doi.org/ 10.3390/app14167298. Han, Z., Ma, Y., Wang, M., 2025. Ferritin protein nanocages for selective separation and recovery of critical metals. Environ. Sci. Technol. Lett. 12, 567–572. https://doi.org/ 10.1021/acs.estlett.5c00181. Hou, Y., Liu, D., Zhao, F., Zhang, S., Zhang, Q., Emmanuel, N.N., Zhong, L., 2022. Mineralogical and geochemical characteristics of coal from the Southeastern Qinshui Basin: implications for the enrichment and economic value of Li and REY. Int. J. Coal Geol. 264, 104136. https://doi.org/10.1016/j.coal.2022.104136. Hu, H., Wang, J., 2021. Selective extraction of rare earths and lithium from rare earth fluoride molten-salt electrolytic slag by nitration. Hydrometallurgy 200, 105552. https://doi.org/10.1016/j.hydromet.2021.105552. Hu, P., Hou, X., Zhang, J., Li, S., Wu, H., Damø, A.J., Li, H., Wu, Q., Xi, X., 2018. Distribution and occurrence of lithium in high-alumina-coal fly ash. Int. J. Coal Geol. 189, 27–34. https://doi.org/10.1016/j.coal.2018.02.011. Huang, Z., Zhang, S., Cheng, C., Wang, H., Liu, R., Hu, Y., He, G., Yu, X., Fu, W., 2020. Recycling lepidolite from Tantalum–Niobium Mine tailings by a combined magnetic–flotation process using a novel gemini surfactant: from tailings dams to the L. Bartoˇ nov´ a et al. Resources Policy 112 (2026) 105790 16 “bling” raw material of lithium. ACS Sustain. Chem. Eng. 8, 18206–18214. https:// doi.org/10.1021/acssuschemeng.0c06609. Hudson-Edwards, K.A., Kemp, D., Torres-Cruz, L.A., Macklin, M.G., Brewer, P.A., Owen, J.R., Franks, D.M., Marquis, E., Thomas, C.J., 2024. Tailings storage facilities, failures and disaster risk. Nat. Rev. Earth Environ. 5, 612–630. https://doi.org/ 10.1038/s43017-024-00576-4. Ilyas, S., Srivastava, R.R., Pathak, P., 2025. Selective extraction of cobalt and lithium phosphates from spent LiCoO 2 cathode cells: a TRL-4 study on process, kinetics, and techno-economics. Ind. Eng. Chem. Res. https://doi.org/10.1021/acs.iecr.4c04662 acs.iecr.4c04662. International Energy Agency, 2024. Global Critical Minerals Outlook 2024. International Energy Agency, 2023. Overall Supply and Demand of Lithium for Batteries by Sector, pp. 2016–2022. International Energy Agency, 2021. Total Lithium Demand by Sector and Scenario, pp. 2020–2040. Iqbal, A., Iftekhar, S., Ashraf, A., Asif, M.B., 2023. Bioleaching of metals from various waste resources. In: Resource Recovery in Industrial Waste Waters. Elsevier, pp. 115–141. https://doi.org/10.1016/B978-0-323-95327-6.00008-7. Iqbal, Z., 2015. Recovery of Lithium from Kaolin Mining Waste Material (PhD Thesis). University of Birmingham, School of Chemical Engineering. Jandov´ a, J., Dvoˇ r´ ak, P., Vu, H.N., 2010. Processing of zinnwaldite waste to obtain Li 2 CO 3 . Hydrometallurgy 103, 12–18. https://doi.org/10.1016/j. hydromet.2010.02.010. Jandov´ a, J., Vu, H.N., Belkov´ a, T., Dvoˇ r´ ak, P., Kond´ as, J., 2009. Obtaining Li 2 CO 3 from zinnwaldite wastes. Ceram. - Silik´ aty 53, 108–112. Jedrusiak, R., Bielowicz, B., Drobniak, A., 2023. From waste to value: recovering critical raw materials from urban mines in the European Union and United States. Gospod. Surowcami Miner. - Miner. Resour. Manag. https://doi.org/10.24425/ gsm.2023.147557. Kang, C., Yang, S., Qiao, J., Zhao, Y., Dong, S., Wang, Y., Duan, C., Liu, J., 2024. Extraction of valuable critical metals from coal gangue by roasting activationsulfuric acid leaching. Int. J. Coal Prep. Util. 1–18. https://doi.org/10.1080/ 19392699.2023.2301311. Kantor, P., Raclavska, H., Matysek, D., Raclavsky, K., Svedova, B., Kucbel, M., 2019. Sources of magnetic particles from air pollution in mountainous area. In˙ z. Miner. 1. https://doi.org/10.29227/IM-2019-01-08. Kazmi, B., Ali Ammar Taqvi, S., Raza Naqvi, S., Ali Mirani, A., Shahbaz, M., Naqvi, M., Juchelkov´ a, D., Eldesoky, G.E., 2023. Techno-economic assessment of sunflower husk pellets treated with waste glycerol for the Bio-hydrogen production– A Simulation-based case study. Fuel 348, 128635. https://doi.org/10.1016/j. fuel.2023.128635. Ketris, M.P., Yudovich, YaE., 2009. Estimations of Clarkes for carbonaceous biolithes: world averages for trace element contents in black shales and coals. Int. J. Coal Geol. 78, 135–148. https://doi.org/10.1016/j.coal.2009.01.002. Kong, L., Yan, G., Hu, K., Yu, Y., Conte, N., Mckenzie Jr, K.R., Wagner, M.J., Boyes, S.G., Chen, H., Liu, C., Liu, X., 2025. Electro-driven direct lithium extraction from geothermal brines to generate battery-grade lithium hydroxide. Nat. Commun. 16, 806. https://doi.org/10.1038/s41467-025-56071-x. Koohi-Fayegh, S., Rosen, M.A., 2020. A review of energy storage types, applications and recent developments. J. Energy Storage 27, 101047. https://doi.org/10.1016/j. est.2019.101047. Kristianov´ a, E., Vu, NgH., Dvoˇ r´ ak, P., Tomaˇ sko, T., Vaculíkov´ a, L., 2023. Extraction of Li, K, and Rb from zinnwaldite by chlorination roasting with CaCl 2 . Miner. Eng. 204, 108420. https://doi.org/10.1016/j.mineng.2023.108420. Kuang, G., Li, H., Hu, S., Jin, R., Liu, S., Guo, H., 2015. Recovery of aluminium and lithium from gypsum residue obtained in the process of lithium extraction from lepidolite. Hydrometallurgy 157, 214–218. https://doi.org/10.1016/j. hydromet.2015.08.020. Kucbel, M., Raclavsk´ a, H., Růˇ ziˇ ckov´ a, J., ˇ Sv´ edov´ a, B., Sassmanov´ a, V., Drozdov´ a, J., Raclavský, K., Juchelkov´ a, D., 2019. Properties of composts from household food waste produced in automatic composters. J. Environ. Manag. 236, 657–666. https:// doi.org/10.1016/j.jenvman.2019.02.018. Kucbel, M., Raclavsk´ a, H., Slamov´ a, K., ˇ Saf´ aˇ r, M., ˇ Sv´ edov´ a, B., Juchelkov´ a, D., Růˇ ziˇ ckov´ a, J., 2024. Environmental impact assessment of the coal yard and ambient pollution. Environ. Sci. Pollut. Res. https://doi.org/10.1007/s11356-024-32490-z. Kumar, S., Bhardwaj, S., Sharma, A., Sharma, V., 2023. W-Li potentials in the tailing dumps of Rewat hill, Degana, Rajasthan, NW India; constraints from petrography and geochemistry. J. Geol. Soc. India 99, 1438–1444. https://doi.org/10.1007/ s12594-023-2490-y. Kumkrong, P., Dy, E., Tyo, D.D., Jiang, C., Gedara Pihilligawa, I., Kingston, D., Mercier, P.H.J., 2022. Investigation of metal mobility in gold and silver mine tailings by single-step and sequential extractions. Environ. Monit. Assess. 194, 423. https:// doi.org/10.1007/s10661-022-10054-3. L` ebre, ´ E., Corder, G., 2015. Integrating industrial ecology thinking into the management of mining waste. Resources 4, 765–786. https://doi.org/10.3390/ resources4040765. Lei, Q., Zhou, K., Zhang, X., Salih, K.A.M., Peng, C., He, D., Chen, W., 2024. Clean and efficient synthesis of LiFePO4 cathode material using titanium white waste and calcium dihydrogen phosphate. Waste Manag. 174, 362–370. https://doi.org/ 10.1016/j.wasman.2023.12.019. Li, C., Zhou, C., Li, W., Zhu, W., Shi, J., Liu, G., 2023a. Enrichment of critical elements from coal fly ash by the combination of physical separations. Fuel 336, 127156. https://doi.org/10.1016/j.fuel.2022.127156. Li, C., Zhou, C., Li, W., Zhu, W., Shi, J., Wu, L., Liu, G., 2024a. A two-stage process of alkali fusion and organic acid leaching for recovery of critical elements from coal fly ash. J. Ind. Eng. Chem. 138, 131–143. https://doi.org/10.1016/j.jiec.2024.03.047. Li, H., Feng, Y., Li, Haoran, Liu, Z., 2022a. Microbial pretreatment of microfine-grained low-grade zinnwaldite tailings for enhanced flotation to recover lithium and rubidium resources. Miner. Eng. 181, 107503. https://doi.org/10.1016/j. mineng.2022.107503. Li, J., Gao, J.-M., Guo, Y., Cheng, F., 2022b. Energy-efficient leaching process for preparation of aluminum sulfate and synergistic extraction of Li and Ga from circulating fluidized bed fly ash. Energy sources part recovery util. Environ. Eff. 44, 4398–4410. https://doi.org/10.1080/15567036.2022.2077476. Li, J., Liu, L., Kang, X., Li, K., Zhang, S., Liu, Q., 2023b. Enrichment of lithium in the claystone coal gangue from the Malan mine, Xishan Coalfield, Shanxi Province, Northern China. Geochemistry 83, 125972. https://doi.org/10.1016/j. chemer.2023.125972. Li, Jing, Zhuang, X., Yuan, W., Liu, B., Querol, X., Font, O., Moreno, N., Li, Jianfu, Gang, T., Liang, G., 2016. Mineral composition and geochemical characteristics of the Li-Ga-rich coals in the Buertaohai-Tianjiashipan mining district, Jungar Coalfield, Inner Mongolia. Int. J. Coal Geol. 167, 157–175. https://doi.org/10.1016/ j.coal.2016.09.018. Li, S., Qin, S., Kang, L., Liu, J., Wang, J., Li, Y., 2017. An efficient approach for lithium and aluminum recovery from Coal fly ash by pre-desilication and intensified acid leaching processes. Metals 7, 272. https://doi.org/10.3390/met7070272. Li, X., Luo, P., Liu, Z., Tang, X., Zhang, B., Guo, J., 2024b. Recovery of rare earths and lithium from rare earth molten salt electrolytic slag by lime transformation, coleaching and stepwise precipitation. Physicochem. Probl. Miner. Process. https:// doi.org/10.37190/ppmp/186333. Long, X., Liu, C., Yang, Y., Dong, B., Chen, H., Zhang, L., Pan, J., Zhou, C., 2024. Microwave-assisted hydrothermal synthesis of lithium ion-sieve for adsorption of lithium ion in coal gangue leaching solution. Colloids Surf. A Physicochem. Eng. Asp. 682, 132819. https://doi.org/10.1016/j.colsurfa.2023.132819. Mamani, V., Guti´ errez, A., Fern´ andez, A.I., Ushak, S., 2020. Industrial carnallite-waste for thermochemical energy storage application. Appl. Energy 265, 114738. https:// doi.org/10.1016/j.apenergy.2020.114738. Mannu, A., Di Pietro, M.E., Bosello, V., Mulas, G., Ferrario, C., Murgia, F., Foddai, A.F., Magugliani, G., Mossini, E., Macerata, E., Zanoletti, A., Cornelio, A., Calce, S., Bontempi, E., Mele, A., 2025. Selective and sustainable recovery of lithium from black mass via microwave and green leaching techniques. Mater. Sci. Eng. B 323, 118734. https://doi.org/10.1016/j.mseb.2025.118734. Martin, G., P¨ atzold, C., Bertau, M., 2017. Integrated process for lithium recovery from zinnwaldite. Int. J. Miner. Process. 160, 8–15. https://doi.org/10.1016/j. minpro.2017.01.005. Maulidia, A., Sujoto, V.S.H., Sudarmaja, D.P.A., Putri, J.J.E., Jenie, S.N.A., Astuti, W., Supriyatna, Y.I., Warmada, I.W., Sutijan, Anggara, F., Petrus, H.T.B.M., 2023. Kinetic study of lithium leaching from Sidoarjo mud using sulfuric acid. Min. Metall. Explor. 40, 1279–1288. https://doi.org/10.1007/s42461-023-00812-3. Mertineit, M., Schramm, M., 2019. Lithium occurrences in brines from two German salt deposits (Upper Permian) and first results of leaching experiments. Minerals 9, 766. https://doi.org/10.3390/min9120766. Moroeng, O.M., Murathi, B., Wagner, N.J., 2024. Enrichment of rare earth elements in epigenetic dolomite occurring in contact metamorphosed Witbank coals (South Africa). Int. J. Coal Geol. 282, 104405. https://doi.org/10.1016/j. coal.2023.104405. Mousa, E., Hu, X., Ånnhagen, L., Ye, G., Cornelio, A., Fahimi, A., Bontempi, E., Frontera, P., Badenhorst, C., Santos, A.C., Moreira, K., Guedes, A., Valentim, B., 2022. Characterization and thermal treatment of the black mass from spent lithiumion batteries. Sustainability 15, 15. https://doi.org/10.3390/su15010015. Moyle, P.R., Causey, J.D., 2001. Chemical Composition of Samples Collected from Waste Rock Dumps and Other mining-related Features at Selected Phosphate Mines in Southeastern Idaho, Western Wyoming, and Northern Utah, open-file Report 01-411. Nassar, N.T., Graedel, T.E., Harper, E.M., 2015. By-product metals are technologically essential but have problematic supply. Sci. Adv. 1, e1400180. https://doi.org/ 10.1126/sciadv.1400180. Obut, A., Aktosun, Z., Girgin, ˙ I., Deveci, H., Y¨ orüko˘ glu, A., 2022. Characterization and treatment of clayey waste using a sulfuric acid roasting-water leaching process for the extraction of lithium. Physicochem. Probl. Miner. Process. https://doi.org/ 10.37190/ppmp/149635. Ozbas, R., Derum, E.M., 2021. Leaching of lithium and rubidium elements from boron production wastes. J. Chem. Technol. Metall. 56, 845–852. Pan, Y., Wei, D., Yao, S., Zhang, H., Tian, Q., 2024. Extraction of lithium and gallium from coal gasification slag using alkali fusion and water leaching. J. Ind. Eng. Chem. https://doi.org/10.1016/j.jiec.2024.07.030. S1226086X24004751. Parzentny, H.R., R´ og, L., 2019. The role of mineral matter in concentrating uranium and thorium in coal and combustion residues from power plants in Poland. Minerals 9, 312. https://doi.org/10.3390/min9050312. Protopapa, M.L., Burresi, E., Fiore, A., Mirenghi, L., Palazzo, B., Schioppa, M., Tagliente, M.A., Valenzano, V., Taurisano, N., Appetecchi, G.B., 2025. Towards sustainable lithium-ion batteries: a state-of-the-art review on silicon anodes, economics, and recycling. Silicon. https://doi.org/10.1007/s12633-025-03447-9. Qin, Q., Deng, J., Geng, H., Bai, Z., Gui, X., Ma, Z., Miao, Z., 2022. An exploratory study on strategic metal recovery of coal gangue and sustainable utilization potential of recovery residue. J. Clean. Prod. 340, 130765. https://doi.org/10.1016/j. jclepro.2022.130765. Qin, S., Zhao, C., Li, Y., Zhang, Y., 2015. Review of coal as a promising source of lithium. Int. J. Oil Gas Coal Technol. 9, 215. https://doi.org/10.1504/IJOGCT.2015.067490. Qin, Y., Chen, C., Yang, Z., Guo, Y., Cheng, F., Gao, J., 2025. Sources, hazards, and resource utilization of electrolytic aluminum salg: a review. Powder Technol. 468, 121662. https://doi.org/10.1016/j.powtec.2025.121662. L. Bartoˇ nov´ a et al. Resources Policy 112 (2026) 105790 17 Qiu, S., Sun, T., Zhu, Y., Liu, C., Yu, J., 2023. Direct preparation of water-soluble lithium salts from α -spodumene by roasting with different sulfates. Ind. Eng. Chem. Res. 62, 685–697. https://doi.org/10.1021/acs.iecr.2c03744. Raclavsk´ a, H., Kantor, P., Růˇ ziˇ ckov´ a, J., Kucbel, M., ˇ Sv´ edov´ a, B., Slamov´ a, K., Flodrov´ a, ˇ S., Juchelkov´ a, D., 2021. An influence of the fuel type on element behaviour in domestic boilers with respect to the circular economy. Appl. Sci. 11, 4980. https://doi.org/10.3390/app11114980. Raclavsk´ a, H., Růˇ ziˇ ckov´ a, J., ˇ Saf´ aˇ r, M., Kucbel, M., Slamov´ a, K., ˇ Sv´ edov´ a, B., Juchelkov´ a, D., Kantor, P., 2023. Municipal sludges as sources of energy or nutrients – what is the best. Energy 275, 127469. https://doi.org/10.1016/j. energy.2023.127469. Raclavsk´ a, H., Růˇ ziˇ ckov´ a, J., ˇ Skrob´ ankov´ a, H., Koval, S., Kucbel, M., Raclavský, K., ˇ Sv´ edov´ a, B., Pavlík, P., Juchelkov´ a, D., 2018. Possibilities of the utilization of char from the pyrolysis of tetrapak. J. Environ. Manag. 219, 231–238. https://doi.org/ 10.1016/j.jenvman.2018.05.002. Rezaei, H., Shafaei, S.Z., Abdollahi, H., Ghassa, S., Boroumand, Z., Fallah Nosratabad, A., 2023. Spent-medium leaching of germanium, vanadium and lithium from coal fly ash with biogenic carboxylic acids and comparison with chemical leaching. Hydrometallurgy 217, 106038. https://doi.org/10.1016/j.hydromet.2023.106038. Rezaei, H., Ziaedin Shafaei, S., Abdollahi, H., Shahidi, A., Ghassa, S., 2022. A sustainable method for germanium, vanadium and lithium extraction from coal fly ash: sodium salts roasting and organic acids leaching. Fuel 312, 122844. https://doi.org/ 10.1016/j.fuel.2021.122844. Roy, T., Plante, B., Benzaazoua, M., Demers, I., Coudert, L., Turcotte, S., 2022. Geochemistry of decades-old spodumene mine tailings under a humid continental climate. Appl. Geochem. 146, 105481. https://doi.org/10.1016/j. apgeochem.2022.105481. Růˇ ziˇ ckov´ a, J., Kucbel, M., Raclavsk´ a, H., ˇ Sv´ edov´ a, B., Raclavský, K., Juchelkov´ a, D., 2019a. Comparison of organic compounds in char and soot from the combustion o f biomass in boilers of various emission classes. J. Environ. Manag. 236, 769–783. https://doi.org/10.1016/j.jenvman.2019.02.038. Růˇ ziˇ ckov´ a, J., Kucbel, M., Raclavsk´ a, H., ˇ Sv´ edov´ a, B., Raclavský, K., ˇ Saf´ aˇ r, M., Kantor, P., 2019b. Chemical and mineralogical composition of soot and ash from the combustion of peat briquettes in household boilers. Energies 12, 3784. https://doi. org/10.3390/en12193784. Růˇ ziˇ ckov´ a, J., Raclavsk´ a, H., Kucbel, M., Raclavský, K., ˇ Saf´ aˇ r, M., ˇ Sv´ edov´ a, B., 2018. The possibilities to identify combusted fuel based on an analysis of ash from local heating. J. Environ. Manag. 219, 269–276. https://doi.org/10.1016/j. jenvman.2018.05.001. Saikia, B.K., Ward, C.R., Oliveira, M.L.S., Hower, J.C., De Leao, F., Johnston, M.N., O’Bryan, A., Sharma, A., Baruah, B.P., Silva, L.F.O., 2015. Geochemistry and nanomineralogy of feed coals, mine overburden, and coal-derived fly ashes from Assam (North-east India): a multi-faceted analytical approach. Int. J. Coal Geol. 137, 19–37. https://doi.org/10.1016/j.coal.2014.11.002. Samkov´ a, R., 2009. Recovering lithium mica from the waste after mining Sn-W ores through the use of flotation. GoeSci. Eng. LV, 33–37. Santos, A.C., Guedes, A., French, D., Futuro, A., Valentim, B., 2022. Integrative study assessing space and time variations with emphasis on rare earth element (REE) distribution and their potential on ashes from commercial (Colombian) coal. Minerals 12, 194. https://doi.org/10.3390/min12020194. Sarker, S.K., Haque, N., Bhuiyan, M., Bruckard, W., Pramanik, B.K., 2022. Recovery of strategically important critical minerals from mine tailings. J. Environ. Chem. Eng. 10, 107622. https://doi.org/10.1016/j.jece.2022.107622. Scala, F., 2016. Attrition during steam gasification of lignite char in a fluidized bed reactor. Fuel Process. Technol. 141, 38–43. https://doi.org/10.1016/j. fuproc.2015.03.031. Sedda, L., De Giudici, G., Fancello, D., Podda, F., Naitza, S., 2023. Unlocking strategic and critical raw materials: assessment of zinc and rees enrichment in tailings and Zncarbonate in a historical mining area (Montevecchio, SW Sardinia). Minerals 14, 3. https://doi.org/10.3390/min14010003. Shao, S., Ma, B., Wang, C., Chen, Y., 2022. Extraction of valuable components from coal gangue through thermal activation and HNO 3 leaching. J. Ind. Eng. Chem. 113, 564–574. https://doi.org/10.1016/j.jiec.2022.06.033. Sharma, S., Edge, J., Mumford, J., 2023. Evaluating the impact of mining for critical electric vehicle and stationary storage battery minerals on land use and biodiversity. https://doi.org/10.21203/rs.3.rs-3307549/v1. Shuiping, Z., Donghui, L., Wei, W., Xiaopeng, C., Wengze, Z., Wen, T., 2024. Efficient extraction of Li and Rb from zinnwaldite via thermal activation and acid leaching. Miner. Eng. 216, 108898. https://doi.org/10.1016/j.mineng.2024.108898. Shumilova, L.V., Yurgenson, G.A., Khatkova, A.N., 2022. Substantiation of technology for extraction of rare metals from mining wastes using the example of mature tailings at the Orlovsky mining and processing plant (East Transbaikal). Metallurgist 65, 1174–1186. https://doi.org/10.1007/s11015-022-01261-x. Siame, E., Pascoe, R.D., 2011. Extraction of lithium from micaceous waste from China clay production. Miner. Eng. 24, 1595–1602. https://doi.org/10.1016/j. mineng.2011.08.013. Siekierka, A., Bryjak, M., Razmjou, A., Kujawski, W., Nikoloski, A.N., Dum´ ee, L.F., 2022. Electro-driven materials and processes for lithium recovery - a review. Membranes 12, 343. https://doi.org/10.3390/membranes12030343. Sim˜ oes, C.R., Da Silva, M.W.P., De Souza, R.F.M., Hacha, R.R., Merma, A.G., Torem, M. L., Silvas, F.P.C., 2024. Biosurfactants: an overview of their properties, production, and application in mineral flotation. Resources 13, 81. https://doi.org/10.3390/ resources13060081. Spears, D., 2017. The role of seawater on the trace element geochemistry of some UK coals and a tribute to Goldschmidt. Minerals 7, 148. https://doi.org/10.3390/ min7080148. Spears, D.A., 2025. Implications of element enrichment in paralic coals from the Carboniferous in England. Int. J. Coal Geol. 309, 104865. https://doi.org/10.1016/j. coal.2025.104865. Sterba, J., Krzemie´ n, A., Riesgo Fern´ andez, P., Escanciano García-Miranda, C., Fidalgo Valverde, G., 2019. Lithium mining: accelerating the transition to sustainable energy. Resour. Policy 62, 416–426. https://doi.org/10.1016/j. resourpol.2019.05.002. Su, H., Chen, H., Lin, J., 2020. A sequential integration approach using Aspergillus Niger to intensify coal fly ash as a rare metal pool. Fuel 270, 117460. https://doi.org/ 10.1016/j.fuel.2020.117460. Sun, F., Dai, S., Wang, L., Xing, L., Gui, X., 2024. Pre-enrichment experiment of high gradientmagnetic separation based on lithium and gallium elements in coal gangue. Clean Coal Technol. 30, 154–162. https://doi.org/10.13226/j.issn.1006-6772. KD23121501. Sun, H., Zhang, X., Luo, C., 2025. A review of carbon pricing mechanisms and risk management for raw materials in low-carbon energy systems. Energies 18, 3401. https://doi.org/10.3390/en18133401. Sun, Y., Li, Y., Zhao, C., Lin, M., Wang, J., Qin, S., 2010. Concentrations of Lithium in Chinese coals. Energy Explor. Exploit. 28, 97–104. https://doi.org/10.1260/01445987.28.2.97. Sun, Y., Yang, J., Zhao, C., 2012. Minimum mining grade of associated Li deposits in coal seams. Energy Explor. Exploit. 30, 167–170. https://doi.org/10.1260/01445987.30.2.167. Sun, Y.Z., Zhao, C.L., Li, Y.H., Wang, J.X., Lin, M.Y., 2013. Li distribution and mode of occurrence in Li-bearing Coal Seam 9 from Pingshuo Mining District, Ningwu Coalfield, northern China. Energy Educ. Sci. Technol. Part Energy Sci. Res. 31, 27–38. Suss, A., Kuznetsova, N., Ostashin, S., Isakov, E., 2022. Comprehensive processing of Mica concentrate from Yaroslavsky GRK for Lithium carbonate, potassium sulfate, aluminum sulfate, rubidium, and cesium. In: Ouchi, T., Azimi, G., Forsberg, K., Kim, H., Alam, S., Neelameggham, N.R., Baba, A.A., Peng, H. (Eds.), Rare Metal Technology 2022, the Minerals, Metals & Materials Series. Springer International Publishing, Cham, pp. 245–258. https://doi.org/10.1007/978-3-030-92662-5_24. ˇ Sv´ edov´ a, B., Kucbel, M., Raclavsk´ a, H., Růˇ ziˇ ckov´ a, J., Raclavský, K., Sassmanov´ a, V., 2019. Water-soluble ions in dust particles depending on meteorological conditions in urban environment. J. Environ. Manag. 237, 322–331. https://doi.org/10.1016/j. jenvman.2019.02.086. Tadesse, B., Makuei, F., Albijanic, B., Dyer, L., 2019. The beneficiation of lithium minerals from hard rock ores: a review. Miner. Eng. 131, 170–184. https://doi.org/ 10.1016/j.mineng.2018.11.023. Tang, B., Fu, Y., Yan, S., Chen, P.-W., Cao, C., Guo, C., Wu, P., Long, Z., Long, K.-S., Wang, T.-S., Liu, Y., Yang, Y., 2022. The source, host minerals, and enrichment mechanism of lithium in the Xinmin bauxite deposit, northern Guizhou, China: constraints from lithium isotopes. Ore Geol. Rev. 141, 104653. https://doi.org/ 10.1016/j.oregeorev.2021.104653. Tang, C., Wang, J., Yang, S., Zhang, X., Li, S., Lai, Y., Tian, Z., Jin, S., Chen, Y., 2023. Efficient extraction and recovery of lithium from waste aluminum cryolite electrolyte. Resour. Conserv. Recycl. 197, 107070. https://doi.org/10.1016/j. resconrec.2023.107070. Tang, Y., Yang, Y., Zhao, H., Zheng, Z., Wu, J., Xue, Y., Zhang, X., Pan, D., 2025. Critical review of lithium recovery from spent aluminum electrolyte: mechanisms, economics, and environmental assessment. Renew. Sustain. Energy Rev. 226, 116271. https://doi.org/10.1016/j.rser.2025.116271. Tavakoli Mohammadi, M.R., Javad Koleini, S.M., Javanshir, S., Abolghasemi, H., Abdollahy, M., 2015. Extraction of rubidium from gold waste: process optimization. Hydrometallurgy 151, 25–32. https://doi.org/10.1016/j.hydromet.2014.10.016. Tian-ming, G., Na, F., Wu, C., Tao, D., MNR key laboratory of metallogeny and mineral assessment, institute of mineral resources Chinese academy of geological sciences, Beijing 100037, China, Res.Center Strategy Glob. Mineral Resour., Chin. Geolog Survey, Beijing 100037, China, China Huanqiu Contracting & Engineering Corp., LTD Beijing Branch, Beijing 100012, China, SDU Life Cycle Engineering, Department of Green Technology, University of Southern Denmark, Odense 5230, Denmark, 2023. Lithium extraction from hard rock lithium ores (spodumene, lepidolite, zinnwaldite, petalite): Technology, resources, environment and cost. China Geol. 6, 137–153. https://doi.org/10.31035/cg2022088. Timich, M., Contessotto, R., Ulsen, C., 2023. Process mineralogy of Li-enriched pegmatite combining laboratory mineral separations and SEM-based automated image analysis. Minerals 13, 343. https://doi.org/10.3390/min13030343. Tiruta-Barna, L., Benetto, E., Perrodin, Y., 2007. Environmental impact and risk assessment of mineral wastes reuse strategies: review and critical analysis of approaches and applications. Resour. Conserv. Recycl. 50, 351–379. https://doi.org/ 10.1016/j.resconrec.2007.01.009. Tong, Z., Hu, X., Wen, H., 2023. Effect of roasting activation of rare earth molten salt slag on extraction of rare earth, lithium and fluorine. J. Rare Earths 41, 300–308. https:// doi.org/10.1016/j.jre.2022.02.014. Tun, M.M., Raclavsk´ a, H., Juchelkov´ a, D., Růˇ ziˇ ckov´ a, J., ˇ Saf´ aˇ r, M., ˇ Strbov´ a, K., Gikas, P., 2020. Spent coffee ground as renewable energy source: evaluation of the dryi ng processes. J. Environ. Manag. 275, 111204. https://doi.org/10.1016/j. jenvman.2020.111204. Urakaev, F.Kh, Shumskaya, L.G., Kirillova, E.A., Kondrat’ev, S.A., 2020. Improvement of fine milling technology for mining waste based on proportioned stage-wise disintegration. J. Min. Sci. 56, 828–837. https://doi.org/10.1134/ S1062739120057178. US Geological Survey, 2024. Distribution of Lithium end-usage Worldwide in 2023, by Area of Applic Ation. Statista. L. Bartoˇ nov´ a et al. Resources Policy 112 (2026) 105790 18 Villa Gomez, D., Whitworth, A.J., Vaughan, J., Sultana, U., Ledezma, P., ParbhakarFox, A., 2024. Review on developments in technologies for critical metal recovery from mining and processing wastes. Miner. Process. Extr. Metall. Rev. 1–20. https:// doi.org/10.1080/08827508.2024.2408015. Vivoda, V., Bazilian, M.D., Khadim, A., Ralph, N., Krame, G., 2024a. Lithium nexus: energy, geopolitics, and socio-environmental impacts in Mexico’s Sonora project. Energy Res. Social Sci. 108, 103393. https://doi.org/10.1016/j.erss.2023.103393. Vivoda, V., Loginova, J., 2025. Lithium at the crossroads: geopolitical, economic, and socio-environmental complexities of the Jadar project in Serbia. Miner. Econ. 38, 665–681. https://doi.org/10.1007/s13563-025-00517-7. Vivoda, V., Loginova, J., Kemp, D., 2025a. Geopolitics and mine waste: an overview and future research directions. J. Environ. Manag. 385, 125545. https://doi.org/ 10.1016/j.jenvman.2025.125545. Vivoda, V., Matthews, R., Andresen, J., 2025b. Securing defense critical minerals: challenges and U.S. strategic responses in an evolving geopolitical landscape. Comp. Strategy 44, 281–315. https://doi.org/10.1080/01495933.2025.2456427. Vivoda, V., Matthews, R., McGregor, N., 2024b. A critical minerals perspective on the emergence of geopolitical trade blocs. Resour. Policy 89, 104587. https://doi.org/ 10.1016/j.resourpol.2023.104587. Vrbický, T., Pˇ rikryl, R., 2021. Recovery of some critical raw materials from processing waste of feldspar ore related to hydrothermally altered granite: laboratory-scale beneficiation. Minerals 11, 455. https://doi.org/10.3390/min11050455. Vu, H., Bernardi, J., Jandov´ a, J., Vaculíkov´ a, L., Goli´ aˇ s, V., 2013. Lithium and rubidium extraction from zinnwaldite by alkali digestion process: sintering mechanism and leaching kinetics. Int. J. Miner. Process. 123, 9–17. https://doi.org/10.1016/j. minpro.2013.04.014. Wærsted, F.M., Reinoso-Maset, E., Salbu, B., Skipperud, L., 2023. Limited access to oxygen reduces the release of harmful trace elements from submerged alum shale debris. Sci. Total Environ. 880, 163035. https://doi.org/10.1016/j. scitotenv.2023.163035. Wagner, N.J., 2008. The characterization of weathered discard coals and their behaviour during combustion. Fuel 87, 1687–1697. https://doi.org/10.1016/j. fuel.2007.09.009. Wagner, N.J., Matiane, A., 2018. Rare earth elements in select Main Karoo Basin (South Africa) coal and coal ash samples. Int. J. Coal Geol. 196, 82–92. https://doi.org/ 10.1016/j.coal.2018.06.020. Wang, D., Li, P., Qu, W., Yin, L., Zhao, Z., Lei, Z., Wen, S., 2013. Discovery and preliminary study of the high tungsten and lithium contents in the Dazhuyuan bauxite deposit, Guizhou, China. Sci. China Earth Sci. 56, 145–152. https://doi.org/ 10.1007/s11430-012-4504-2. Wang, J., Hu, H., Wu, K., 2020. Extraction of lithium, rubidium and cesium from lithium porcelain stone. Hydrometallurgy 191, 105233. https://doi.org/10.1016/j. hydromet.2019.105233. Wang, X., Cheng, W., Yang, R., Zang, J., 2024. Characterization and acid leaching of rare earth elements in coal gangue using pretreatment of selective grinding, tailings discarding and alkali roasting. J. Rare Earths. https://doi.org/10.1016/j. jre.2024.02.018. S1002072124000632. Wang, Y., Dong, Y., Wang, M., Xu, H., 2025. Recovery of lithium from spent aluminum electrolyte through a novel acidic complex leaching process. Green Chem. Lett. Rev. 18, 2525091. https://doi.org/10.1080/17518253.2025.2525091. Wei, P., Wang, C., Wan, K., Miao, Z., 2025. Study on recovering the scattered metals from coal gangue by low-temperature activation and two-stage selective leaching. Sep. Purif. Technol. 357, 130214. https://doi.org/10.1016/j.seppur.2024.130214. Wiero´ nska-Wi´ sniewska, F., Makowska, D., Strugała, A., 2022. Arsenic in polish coals: content, mode of occurrence, and distribution during coal combustion process. Fuel 312, 122992. https://doi.org/10.1016/j.fuel.2021.122992. Wu, L., Zhang, J., Huang, Z., Zhang, Y., Xie, F., Zhang, S., Fan, H., 2023. Extraction of lithium as lithium phosphate from bauxite mine tailings via mixed acid leaching and chemical precipitation. Ore Geol. Rev. 160, 105621. https://doi.org/10.1016/j. oregeorev.2023.105621. Xie, Y., Han, Z., Khan, A., Liang, Y., Zhong, H., He, Z., 2025a. Selective extraction of lithium from coal gangue utilizing a two-stage roasting process. Miner. Eng. 224, 109197. https://doi.org/10.1016/j.mineng.2025.109197. Xie, Y., Han, Z., Khan, A., Liang, Y., Zhong, H., He, Z., 2025b. Highly selective and green recovery of lithium from coal gangue using recyclable ammonium fluoride leaching system. JOM 77, 842–850. https://doi.org/10.1007/s11837-024-06987-4. Xie, Y., Ni, C., Han, Z., Liao, J., Xie, W., Zhong, H., He, Z., 2024. Recovery of lithium from coal gangue utilizing acid baking followed by water leaching. Int. J. Coal Prep. Util. 44, 82–94. https://doi.org/10.1080/19392699.2023.2174109. Xie, Y., Ni, C., Han, Z., Zhong, H., He, Z., Sun, W., 2023. High recovery of lithium from coal residue by roasting and sulfuric acid leaching. Miner. Eng. 202, 108284. https://doi.org/10.1016/j.mineng.2023.108284. Xing, M., Zhang, F., Zheng, P., Wang, Y., Zhao, L., Xu, C., 2024. Selective recovery of lithium from high-aluminum fly ash by using alkali-dissolution-assisted HBTA–TOPO synergistic extraction. J. Clean. Prod. 434, 139998. https://doi.org/10.1016/j. jclepro.2023.139998. Xu, F., Qin, S., Li, S., Wang, J., Qi, D., Lu, Q., Xing, J., 2022. Distribution, occurrence mode, and extraction potential of critical elements in coal ashes of the Chongqing Power Plant. J. Clean. Prod. 342, 130910. https://doi.org/10.1016/j. jclepro.2022.130910. Xu, H., Liu, C., Mi, X., Wang, Z., Han, J., Zeng, G., Liu, P., Guan, Q., Ji, H., Huang, S., 2021. Extraction of lithium from coal fly ash by low-temperature ammonium fluoride activation-assisted leaching. Sep. Purif. Technol. 279, 119757. https://doi. org/10.1016/j.seppur.2021.119757. Yang, B., Cheng, C., Li, Y., Cheng, W., Zang, J., Lai, X., Wang, X., 2022. Modes of occurrence and pre-concentration of rare earth elements in No. 17 coal in Liupanshui coalfield, China. J. Rare Earths 40, 1323–1332. https://doi.org/10.1016/j. jre.2021.09.001. Yang, D., Yu, M., Mubula, Y., Yuan, W., Huang, Z., Lin, B., Mei, G., Qiu, T., 2024. Recovering rare earths, lithium and fluorine from rare earth molten salt electrolytic slag using sub-molten salt method. J. Rare Earths 42, 1774–1781. https://doi.org/ 10.1016/j.jre.2023.08.009. Yang, J., Zhao, Y., Zyryanov, V., Zhang, J., Zheng, C., 2014. Physical–chemical characteristics and elements enrichment of magnetospheres from coal fly ashes. Fuel 135, 15–26. https://doi.org/10.1016/j.fuel.2014.06.033. Yang, M., Zhong, Y., Liu, X., Wang, S., Qu, T., 2025a. Review of technologies to extract lithium from hard rock lithium minerals. Miner. Eng. 232, 109577. https://doi.org/ 10.1016/j.mineng.2025.109577. Yang, Z., Li, Y., Lou, Q., Liu, D., Ning, Y., Yang, S., Tang, Y., Zhang, Y., Tang, Z., Wang, X., 2019. Release of uranium and other trace elements from coal ash by (NH 4 ) 2 SO 4 activation of amorphous phase. Fuel 239, 774–785. https://doi.org/ 10.1016/j.fuel.2018.11.032. Yang, Z., Xiao, F., Sun, S., Zhou, Z., Chen, Jingyi, Luo, X., Chen, Junqiang, Tu, G., Sui, C., Yu, K., 2025b. The recovery of valuable elements from rare earth molten salt electrolytic slag by the fluorination-vacuum distillation method. Sustain. Mater. Technol. 46, e01670. https://doi.org/10.1016/j.susmat.2025.e01670. Yaroshevsky, A.A., 2006. Abundances of chemical elements in the Earth’s crust. Geochem. Int. 44, 48–55. https://doi.org/10.1134/S001670290601006X. Yazıcı, E.Y., Deveci, H., Celep, O., Ahlatci, F., Yılmaz, E., Esen, E., Dorfling, C., Van Schalkwyk, R.F., Akdogan, G., Louw, L., Maritz, R.F., Kuhn, M.W.J., Vooght, D.T., Emilsson, E., Wu, A., Elginoz, N., Ots, J., Ozturk, A.N., Petranikova, M., Cuhadar, E., Eyupoglu, C., Torunoglu, E.E., 2025. Techno-economic and environmental assessments for hydrometallurgical treatment of waste lithium-ion batteries (LIBs): the ELiMINATE project. Physicochem. Probl. Miner. Process. https://doi.org/ 10.37190/ppmp/204772. Yoo, H., Kim, C., Jang, H.-J., Hong, H.-J., 2024. Synthesis of highly porous layered hydrogen titanium oxide(HTO) granule by using carboxymethylated cellulose nanofibrils(CMCNFs) for effective recovery of Lithium(Li) from low-grade brines. Chem. Eng. J. 489, 151206. https://doi.org/10.1016/j.cej.2024.151206. Yuan, D., Wang, X., Yan, D., Li, J., Li, B., Liu, B., Liu, Z., Zhang, L., 2024. An original set of nanometer-scale mineralogical analyses of cookeite and the implications for Li enrichment: no. 21 coal, Mengjin Mine, Western Henan. Int. J. Coal Geol. 283, 104445. https://doi.org/10.1016/j.coal.2024.104445. Yudovich, YaE., Ketris, M.P., 2015. Geochemistry of coal: occurrences and environmental impacts of trace elements (chapter 3). In: Coal Production and Processing Technology, Boka Raton. CRC Press, pp. 48–73. Yurkevich, N., Olenchenko, V., Kartoziia, A., Korneeva, T., Bortnikova, S., Saeva, O., Tulisova, K., Abrosimova, N., 2023. Hydrochemical anomalies in the vicinity of the abandoned molybdenum ores processing zailings in a permafrost region (Shahtama, Transbaikal Region). Water 15, 1476. https://doi.org/10.3390/w15081476. Yusupov, T.S., Isupov, V.P., Vladimirov, A.G., Zagorsky, V.E., Kirillova, E.A., Shumskaya, L.G., Shatskaya, S.S., Lyakhov, N.Z., 2015. Analysis of material composition and dissociation potential of minerals in mine waste to assess productivity of lithium concentrates. J. Min. Sci. 51, 1242–1247. https://doi.org/ 10.1134/S106273911506054X. Zhang, H., Han, Y., Lai, J., Wolf, J., Lei, Z., Yang, Y., Shi, F., 2024. Direct extraction of lithium from ores by electrochemical leaching. Nat. Commun. 15, 5066. https://doi. org/10.1038/s41467-024-48867-0. Zhang, L., Chen, H., Pan, J., He, X., Shi, S., Long, X., Shi, M., Zhou, C., 2025. Partitioning behavior of lithium and rare earth elements during coal preparation and their differences in mode of occurrence. Miner. Process. Extr. Metall. Rev. 1–12. https:// doi.org/10.1080/08827508.2025.2459643. Zhang, L., Chen, H., Pan, J., Wen, Z., Shi, S., Long, X., Zhou, C., 2022. The effect of physical separation and calcination on enrichment and recovery of critical elements from coal gangue. Minerals 12, 1371. https://doi.org/10.3390/min12111371. Zhang, L., Chen, H., Pan, J., Yang, F., Liu, H., Zhou, C., Zhang, N., 2023. Extraction of lithium from coal gangue by a roasting-leaching process. Int. J. Coal Prep. Util. 43, 863–878. https://doi.org/10.1080/19392699.2022.2083611. Zhang, W., Honaker, R., 2020. Characterization and recovery of rare earth elements and other critical metals (Co, Cr, Li, Mn, Sr, and V) from the calcination products of a coal refuse sample. Fuel 267, 117236. https://doi.org/10.1016/j.fuel.2020.117236. Zhang, W., Noble, A., Yang, X., Honaker, R., 2020. Lithium leaching recovery and mechanisms from density fractions of an Illinois Basin bituminous coal. Fuel 268, 117319. https://doi.org/10.1016/j.fuel.2020.117319. Zhang, Y., Zhang, J., Wu, L., Tan, L., Xie, F., Cheng, J., 2021. Extraction of lithium and aluminium from bauxite mine tailings by mixed acid treatment without roasting. J. Hazard. Mater. 404, 124044. https://doi.org/10.1016/j.jhazmat.2020.124044. Zhou, C., Li, C., Li, W., Sun, J., Li, Q., Wu, W., Liu, G., 2022. Distribution and preconcentration of critical elements from coal fly ash by integrated physical separations. Int. J. Coal Geol. 261, 104095. https://doi.org/10.1016/j. coal.2022.104095. Zhou, T., Zhang, C., Xu, R., Luo, S., Li, W., Liu, Y., 2025. Recovery of valuable metals from lithium-containing aluminum electrolyte slag via an NaOH leaching-agingwater leaching process. RSC Sustain. 3, 3080–3087. https://doi.org/10.1039/ D5SU00210A. Zou, J., Chen, H., Zhao, L., Wang, X., Li, H., Li, T., Wang, H., 2023. Enrichment of critical elements (Li-Ga-Nb-Ta-REE-Y) in the coals and host rocks from the Daping Mine, Yudongnan Coalfield, SW China. Ore Geol. Rev. 152, 105245. https://doi.org/ 10.1016/j.oregeorev.2022.105245. Zuo, G., Li, H., Sun, M., Lin, J., Wang, Z., Tian, Z., Xiao, L., 2022. Coal No.2 lithium distribution pattern and provenance analysis 620 in Xuangang Mining Area,Ningwu Coalfield. Coal Geol. China 34, 7–12. L. Bartoˇ nov´ a et al. Resources Policy 112 (2026) 105790 19