Insight into the occurrence relationships between Pb, As, Zn and Cr with minerals phases in the coal gangue: A novel quantitative dissociation method

Abstract

Establishing the quantitative relationships between heavy metals and mineral phases in coal gangue is essential for its comprehensive landfill and refined utilization. In this study, the Guandi coal gangue was subjected to a stepwise dissociation method using seven concentration gradients (0.1, 1.0, 4.0, 6.0, 8.0, 10.0, 12.0 mol/L) of aqua regia and hydrofluoric acid. Combined with the Rietveld refinement method, inverse matrix calculations of residual fractions of mineral phases and dissociation degrees of heavy metals after dissociation, the quantitative relationships between Pb, As, Zn, Cr and the mineral phases were determined. The results show that kaolinite, quartz, pyrite, and the amorphous phase are the primary host phases for Pb, As, Zn, and Cr, with their contents in crystalline phases ranging from 71.36% to 87.68%. Validation via the standard addition method demonstrates that the relative standard deviation of the stepwise dissociation for Pb, As, Zn, and Cr is ≤7.23%, with spike recovery rates ranging from 85.43% to 112.85%, indicating favorable test results. Sequential chemical leaching demonstrates that heavy metals are mainly distributed in stable aluminosilicate-bound state and carbonate or oxide-bound state. The toxicity characteristic leaching procedure test indicated that Cr exhibited high toxicity and thus required long-term monitoring. The results of this study provide important theoretical guidance for the comprehensive landfilling and resource utilization of Guandi coal gangue, and the established analytical method can be extended to studies on quantitative relationships between heavy metals and mineral phases in other tailings.

Keywords

Coal gangue / Quantitative analysis / Heavy metals / Mineral phases / Ecological risk

CRediT authorship contribution statement

Yichao Chen: Writing - review & editing, Writing - original draft, Visualization, Software, Project administration, Investigation, Data curation, Conceptualization. Wanyao Li: Writing - review & editing, Software, Methodology, Investigation, Data curation, Conceptualization. Haofei Li: Validation, Software, Resources, Methodology, Investigation, Formal analysis. Yuhong Qin: Visualization, Validation, Supervision, Software, Resources, Project administration, Methodology, Funding acquisition, Formal analysis, Data curation, Conceptualization. Shugang Guo: Software, Resources, Funding acquisition, Data curation. Bin Fang: Validation, Resources, Formal analysis, Data curation. Yujia Du: Supervision, Software, Resources, Formal analysis, Data curation. Jin Yuan: Resources, Investigation, Funding acquisition. Leteng Lin: Formal analysis.

Declaration of competing interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Acknowledgments

This work was supported by the National Natural Science Foundation of China (Grant number 21975172) and Natural Science Foundation of Shanxi Province (Grant number 202303021221048). The authors acknowledge the assistance of the Instrumental Analysis Center at Taiyuan University of Technology.

References

[1] Ashfaq, M., Heeralal, M., Arif Ali Baig Moghal, M.A., 2020. Effect of coal gangue particle size on its leaching characteristics. GeoCongress 107-114. https://ascelibrary.org/ doi/10.1061/9780784482827.012.

[2] Ashfaq, M., Moghal, A.A.B., Basha, B.M., 2022. The sustainable utilization of coal gangue in geotechnical and geoenvironmental applications. J. Hazard. Toxic Radioact. Waste 26 (3), 122003. https://doi.org/10.1061/(ASCE)HZ.2153-5515.0000705.

[3] Chen, H., Zhang, L., Pan, J., Long, X., He, X., Shi, S., Yang, Y., Zhang, H., Zhou, C., 2024. Study on the leaching behavior differences of rare Earth elements from coal gangue through calcination-acid leaching. Sep. Purif. Technol. 344, 127222. https://doi.org/10.1016/j.seppur.2024.127222.

[4] Chen, L., Zhou, S., Shi, Y., Wang, C., Li, B., Li, Y., Wu, S., 2018. Heavy metals in food crops, soil, and water in the lihe river watershed of the Taihu region and their potential health risks when ingested. Sci. Total Environ. 615, 141-149. https://doi.org/10.1016/j.scitotenv.2017.09.230.

[5] Dai, S., Sun, F., Wang, L., Wang, L., 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.

[6] Deng, H., Tian, C., Li, L., Liang, Y., Yan, S., Hu, M., Xu, W., Lin, Z., Chai, L., 2022. Microinteraction analysis between heavy metals and coexisting phases in heavy metal containing solid wastes. ACS EST Engg 2, 547-563. https://doi.org/10.1021/acsestengg.1c00343.

[7] Dong, J., Li, J., Huang, Y., Zhong, J., Dun, K., Wu, M., Zhang, L., Chen, Q., Pan, B., 2024. Understanding the release, migration, and risk of heavy metals in coal gangue: an approach by combining experimental and computational investigations. J. Hazard. Mater. 461, 132707. https://doi.org/10.1016/j.jhazmat.2023.132707.

[8] Dong, Y., Lu, H., Lin, H., 2024. Comprehensive study on the spatial distribution of heavy metals and their environmental risks in high-sulfur coal gangue dumps in China. J. Environ. Sci. 136, 486-497. https://doi.org/10.1016/j.jes.2022.12.023.

[9] Du, Y., Shi, T., Guo, S., Li, H., Qin, Y., Wang, Y., He, C., Wei, Y., 2024. Unraveling the intrinsic mechanism behind the retention of arsenic in the co-gasification of coal and sewage sludge: focus on the role of Ca and Fe compounds. J. Hazard. Mater. 470, 134211. https://doi.org/10.1016/j.jhazmat.2024.134211.

[10] Duan, D., Wang, C., Bai, D., Huang, D., 2024. Representative coal gangue in China: physical and chemical properties, heavy metal coupling mechanism and risk assessment. Sep. Purif. Technol. 37, 101402. https://doi.org/10.1016/j.scp.2023.101402.

[11] Duan, L., Sun, Y., Wang, X., Dou, L., 2021. Potential ecological risks of heavy metals in the coal gangue and their release in different weathering degrees. J. Saf. Environ. 21, 874-881. https://doi.org/10.13637/j.issn.1009-6094.2020.0306.

[12] Gao, H., Linghu, C., Su, D., Zheng, Y., Song, Z., Cheng, F., 2023. Influence of the freeze-thaw process on coal gangue-based ecological restoration materials: performance and ecological risk assessment of heavy metals. Environ. Sci. Pollut. Res. 30, 59048-59061. https://doi.org/10.1007/s11356-023-26721-y.

[13] Gao, L., Liu, Y., Xu, K., Bai, L., Guo, N., Li, S., 2024. A short review of the sustainable utilization of coal gangue in environmental applications. RSC Adv. 14, 39285-39296. https://doi.org/10.1039/D4RA06071G.

[14] Gu, J., Liu, X., Zhang, Z., 2023. Road base materials prepared by multi-industrial solid wastes in China: a review. Constr. Build. Mater. 373. https://doi.org/10.1016/j.conbuildmat.2023.130860.

[15] Hakanson, L., 1980. An ecological risk index for aquatic pollution control.a sedimentological approach. Water Res. 14, 975-1001. https://doi.org/10.1016/0043-1354(80)90143-8.

[16] Hayes, S.M., Webb, S.M., Bargar, J.R., O'Day, P.A., Maier, R.M., Chorover, J., 2012. Geochemical weathering increases lead bioaccessibility in semi-arid mine tailings. Environ. Sci. Technol. 46, 5834-5841. https://doi.org/10.1021/es300603s.

[17] Hua, C., Zhou, G., Yin, X., Wang, C., Chi, B., Cao, Y., Wang, Y., Zheng, Y., Cheng, Z., Li, R., 2018. Assessment of heavy metal in coal gangue: distribution, leaching characteristic and potential ecological risk. Environ. Sci. Pollut. Res. 25, 32321-32331. https://doi.org/10.1007/s11356-018-3118-4.

[18] Huang, Y., Li, J., Song, T., Sun, Q., Kong, G., Wang, F., 2017. Microstructure of coal gangue and precipitation of heavy metal elements. J. Spectrosc. 23, 3128549. https://doi.org/10.1155/2017/3128549.

[19] Ilgen, A.G., Trainor, T.P., 2012. Sb(III) and Sb(V) sorption onto Al-Rich phases: hydrous Al oxide and the clay minerals kaolinite KGa-1b and oxidized and reduced nontronite NAu-1. Environ. Sci. Technol. 46, 843-851. https://doi.org/10.1021/es203027v.

[20] Jin, Y., Liu, Z., Han, L., Zhang, Y., Li, L., Zhu, S., Li, Z.P.J., Wang, D., 2022. Synthesis of coal-analcime composite from coal gangue and its adsorption performance on heavy metal ions. J. Hazard. Mater. 423, 127027. https://doi.org/10.1016/j.jhazmat.2021.127027.

[21] Li, J., Wang, J., 2019. Comprehensive utilization and environmental risks of coal gangue: a review. J. Clean. Prod. 239, 117946. https://doi.org/10.1016/j.jclepro.2019.117946.

[22] Li, Y., Papangelakis, V.G., Perederiy, I., 2009. High pressure oxidative acid leaching of nickel smelter slag: characterization of feed and residue. Hydrometallurgy 97, 185-193. https://doi.org/10.1016/j.hydromet.2009.03.007.

[23] Lin, L., Liu, X., Liang, Y., Xu, W., Li, Y., Lin, Z., 2021. Analysis of mineral phases in heavy-metal hazardous waste under the interdisciplinary scope of data science and chemistry. Prog. Chem. https://doi.org/10.7536/PC211120, 211120-211120.

[24] Liu, C., Ma, S., Wang, X.-h., Ou, Y., Du, H.J.B., 2023. Biodegradation of organic compounds in the coal gangue by bacillus sp. into humic acid. Biodegradation 34, 125-138. https://doi.org/10.1007/s10532-022-10007-0.

[25] Liu, F., Xie, M., Yu, G., Ke, C., Zhao, H., 2021. Study on calcination catalysis and the desilication mechanism for coal gangue. ACS Sustain. Chem. Eng. 9, 10318-10325. https://doi.org/10.1021/acssuschemeng.1c03276.

[26] Liu, L., Liu, Q., Zhang, S., Li, Y., Yang, L., 2022. The thermal transformation behavior and products of pyrite during coal gangue combustion. Fuel 324, 124803. https://doi.org/10.1016/j.fuel.2022.124803.

[27] Liu, Z., Zheng, J., Liu, W., Liu, X., Chen, Y., Ren, X., Ning, P., Lin, Z., 2020. Identification of the key host phases of Cr in fresh chromite ore processing residue (COPR). Sci. Total Environ. 703, 135075. https://doi.org/10.1016/j.scitotenv.2019.135075.

[28] Lv, Y., Liu, L., Yang, P., Xie, G., Zhang, C., Deng, S., 2023. Study on leaching and curing mechanism of heavy metals in magnesium coal based backfill materials. Process Saf. Environ. 177, 1393-1402. https://doi.org/10.1016/j.psep.2023.07.084.

[29] Mei, Y., Pang, J., Wang, X., Chen, E., Wu, D., Ma, J., 2023. Coal gangue geopolymers as sustainable and cost-effective adsorbents for efficient removal of Cu (II). Environ. Technol. Innov. 32, 103416. https://doi.org/10.1016/j.eti.2023.103416.

[30] Ouyang, S., Huang, Y., Gao, H., Guo, Y., Wu, L., Li, J., 2022. Study on the distribution characteristics and ecological risk of heavy metal elements in coal gangue taken from 25 mining areas of China. Environ. Sci. Pollut. Res. 29, 48285-48300. https://doi.org/10.1007/s11356-022-19238-3.

[31] 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.

[32] Qureshi, A.A., Kazi, T.G., Baig, J.A., Arain, M.B., Afridi, H.I., 2020. Exposure of heavy metals in coal gangue soil, in and outside the mining area using BCR conventional and vortex assisted and single step extraction methods. Impact on orchard grass. Chemosphere 255, 126960. https://doi.org/10.1016/j.chemosphere.2020.126960.

[33] Ren, J., Zheng, L., Su, Y., Meng, P., Zhou, Q., Zeng, H., Zhang, T., Yu, H., 2022. Competitive adsorption of Cd(II), Pb(II) and Cu(II) ions from acid mine drainage with zero-valent iron/phosphoric titanium dioxide: XPS qualitative analyses and DFT quantitative calculations. Chem. Eng. J. 445, 136778. https://doi.org/10.1016/j.cej.2022.136778.

[34] Riley, K.W., French, D.H., Farrell, O.P., Wood, R.A., Huggins, F.E., 2012. Modes of occurrence of trace and minor elements in some Australian coals. Int. J. Coal Geol. 94, 214-224. https://doi.org/10.1016/j.coal.2011.06.011.

[35] Román, N., Reich, M., Leisen, M., Morata, D., Barra, F., Deditius, A.P., 2019. Geochemical and micro-textural fingerprints of boiling in pyrite. Geochem. Cosmochim. Acta 246, 60-85. https://doi.org/10.1016/j.gca.2018.11.034.

[36] Runčevski, T., Brown, C.M., 2021. The rietveld refinement method: half of a century anniversary. Cryst. Growth Des. 21, 4821-4822. https://doi.org/10.1021/acs.cgd.1c00854.

[37] Saikia, B., Parthasarathy, G., Borah, R.R., Borthakur, R., 2016. Raman and FTIR spectroscopic evaluation of clay minerals and estimation of metal contaminations in natural deposition of surface sediments from brahmaputra river. Int. J. Eng. Geosci 7, 873-883. https://doi.org/10.4236/ijg.2016.77064.

[38] Shao, S., Ma, B., Wang, C., Chen, Y., 2022. Extraction of valuable components from coal gangue through thermal activation and HNO₃ leaching. J. Ind. Eng. Chem. 113, 564-574. https://doi.org/10.1016/j.jiec.2022.06.033.

[39] Song, W., Xu, R., Li, X., Min, X., Zhang, J., Zhang, H., Hu, X., Li, J., 2023. Soil reconstruction and heavy metal pollution risk in reclaimed cultivated land with coal gangue filling in mining areas. Catena 228, 107147. https://doi.org/10.1016/j.catena.2023.107147.

[40] Song, Y., Li, J., Peng, M., Deng, Z., Yang, J., Liu, W., Shi, Z., Lin, Z., 2019. Identification of Cr(VI) speciation in ferrous sulfate-reduced chromite ore processing residue (rCOPR) and impacts of environmental factors erosion on Cr(VI) leaching. J. Hazard. Mater. 373, 389-396. https://doi.org/10.1016/j.jhazmat.2019.03.097.

[41] Spears, D.A., 2013. The determination of trace element distributions in coals using sequential chemical leaching—A new approach to an old method. Fuel 114, 31-37. https://doi.org/10.1016/j.fuel.2012.09.028.

[42] Sun, Y., Xiao, K., Wang, X., Lv, Z., Mao, M., 2021. Evaluating the distribution and potential ecological risks of heavy metal in coal gangue. Environ. Sci. Pollut. Res. 28, 18604-18615. https://doi.org/10.1016/j.scitotenv.2007.07.053.

[43] Tang, L., Tang, C., Xiao, J., Zeng, P., Tang, M., 2018. A cleaner process for valuable metals recovery from hydrometallurgical zinc residue. J. Clean. Prod. 201, 764-773. https://doi.org/10.1016/j.jclepro.2018.08.096.

[44] Tuo, P., Zhang, Z., Du, P., Hu, L., Li, R., Ren, J., 2024. Changes in coal waste DOM chemodiversity and Fe/Al oxides during weathering drive the fraction conversion of heavy metals. Sci. Total Environ. 926, 172063. https://doi.org/10.1016/j.scitotenv.2024.172063.

[45] USEPA, 1992. Toxicity Characteristic Leaching Procedure (TCLP). Publication SW 846: Test Methods for Evaluating Solid Waste, Physical/Chemical Methods.

[46] Wang, G., Ning, X., Lu, X., Lai, X., Cai, H., Liu, Y., Zhang, T., 2019. Effect of sintering temperature on mineral composition and heavy metals mobility in tailings bricks. Waste Manage. ( Tucson, Ariz.) 93, 112-121. https://doi.org/10.1016/j.wasman.2019.04.001.

[47] Wang, J., Yamada, O., Nakazato, T., Zhang, Z., Suzuki, Y., Sakanishi, K., 2008. Statistical analysis of the concentrations of trace elements in a wide diversity of coals and its implications for understanding elemental modes of occurrence. Fuel 87, 2211-2222. https://doi.org/10.1016/j.fuel.2007.10.012.

[48] Wang, L., Lu, X., Huang, Y., 2013. Determination of Zn distribution and speciation in basic oxygen furnace sludge by synchrotron radiation induced μ-XRF and μ-XANES microspectroscopy. X Ray Spectrom. 42, 423-428. https://doi.org/10.1002/xrs.2494.

[49] Wu, Y., Xi, B., Fang, F., Kou, B., Gang, C., Tang, J., Tan, W., Yuan, Y., Yu, T., 2023. Insights into relationships between polycyclic aromatic hydrocarbon concentration, bacterial communities and organic matter composition in coal gangue site. Environ. Res. 236, 116502. https://doi.org/10.1016/j.envres.2023.116502.

[50] Yan, P., Wen, Z., Wu, Z., Li, G., Zhao, Y., Wang, J., Wang, W., 2024. Intelligent detection of coal gangue in mining operations using multispectral imaging and enhanced RT- DETR algorithm for efficient sorting. Microchem. J. 207, 111789. https://doi.org/10.1016/j.microc.2024.111789.

[51] Zhang, B., Yang, K., Zhang, K., Wang, Q., Wu, N., 2023. Migration transformation, prevention, and control of typical heavy metal lead in coal gangue: a review. Int. J. Coal Sci. Techn. 10, 85. https://doi.org/10.1007/s40789-023-00656-8.

[52] 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.

[53] Zhang, Y., Zhang, Y., Shi, X., Liu, S., Shu, P., Xia, S., 2022. Investigation of thermal behavior and hazards quantification in spontaneous combustion fires of coal and coal gangue. Sci. Total Environ. 843, 157072. https://doi.org/10.1016/j.scitotenv.2022.157072.

[54] Zhao, H., Chen, Y., Duan, X., 2021. Study on the factors affecting the deep reduction of coal gangue containing high contents of iron and sulfur. Fuel 288, 119571. https://doi.org/10.1016/j.fuel.2020.119571.

[55] Zhao, R., Wang, B., Zhang, X., Lee, X., Chen, M., Feng, Q., Chen, S., 2022. Insights into Cr (VI) removal mechanism in water by facile one-step pyrolysis prepared coal gangue- biochar composite. Chemosphere 299, 134334. https://doi.org/10.1016/j.chemosphere.2022.134334.

[56] Zhao, R., Wu, X., Zhu, G., Zhang, X., Liu, F., Mu, W., 2024. Revealing the release and migration mechanism of heavy metals in typical carbonate tailings, East China. J. Hazard. Mater. 464, 132978. https://doi.org/10.1016/j.jhazmat.2023.132978.

[57] Zheng, Q., Zhou, Y., Liu, X., Liu, M., Liao, L., Lv, G., 2024. Environmental hazards and comprehensive utilization of solid waste coal gangue. Prog. Nat. Sci-Mater. 34, 223-239. https://doi.org/10.1016/j.pnsc.2024.02.012.

[58] Zhou, C., Guijian, L., Dun, W., Ting, F., Ruwei, W., Xiang, F., 2014. Mobility behavior and environmental implications of trace elements associated with coal gangue: a case study at the huainan coalfield in China. Chemosphere 95, 193-199. https://doi.org/10.1016/j.chemosphere.2013.08.065.

[59] Zhu, J., Chertow, M.R., 2016. Greening industrial production through waste recovery: “comprehensive Utilization of Resources” in China. Environ. Sci. Technol. 50, 2175-2182. https://doi.org/10.1021/acs.est.5b05098.