{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,14]],"date-time":"2026-10-14T23:20:53Z","timestamp":1792020053342,"version":"4.4.0"},"reference-count":33,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2025,4,11]],"date-time":"2025-04-11T00:00:00Z","timestamp":1744329600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Xining Science and Technology Plan Project","award":["2024-Y-5"],"award-info":[{"award-number":["2024-Y-5"]}]},{"name":"Xining Science and Technology Plan Project","award":["2024ZZTS0216"],"award-info":[{"award-number":["2024ZZTS0216"]}]},{"name":"Fundamental Research Funds for the Central Universities of Central South University","award":["2024-Y-5"],"award-info":[{"award-number":["2024-Y-5"]}]},{"name":"Fundamental Research Funds for the Central Universities of Central South University","award":["2024ZZTS0216"],"award-info":[{"award-number":["2024ZZTS0216"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Materials"],"abstract":"<jats:p>The Hall\u2013H\u00e9roult aluminum production process generates lithium-rich waste barrier materials, which are challenging to process using conventional acid leaching due to the environmental risks posed by hydrofluoric acid (HF) emissions. This research introduces a two-stage water\u2013HCl sequential leaching (WHSL) approach to recover lithium while reducing these environmental impacts. The method evaluates key factors, such as the liquid\u2013solid ratio, temperature, duration, rotation speed, and HCl concentration, and compares its efficacy with traditional HCl leaching using XRD, FTIR, DBP, and SEM techniques. The findings indicate that initial water leaching dissolves NaF salts, creating surface grooves and cracks. Subsequent HCl leaching selectively extracts lithium from aluminum and silicon, forming silica gel while preserving the nepheline phase due to its structural integrity. The process produces a porous residue with smaller particles, reduced surface potential, and promotes colloidal aggregation. This two-step process achieves efficient lithium recovery while reducing acid consumption and minimizing hydrogen fluoride (HF) emissions.<\/jats:p>","DOI":"10.3390\/ma18081748","type":"journal-article","created":{"date-parts":[[2025,4,11]],"date-time":"2025-04-11T03:45:23Z","timestamp":1744343123000},"page":"1748","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":11,"title":["Water\u2013HCl Sequential Leaching of Waste Barrier Material from Aluminum Electrolysis Cell"],"prefix":"10.3390","volume":"18","author":[{"given":"Yujie","family":"Zhao","sequence":"first","affiliation":[{"name":"School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China"},{"name":"Engineering Research Center of Ministry of Education for Carbon Emission Reduction in Metal Resource Exploitation and Utilization, Central South University, Changsha 410083, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Saiya","family":"Li","sequence":"additional","affiliation":[{"name":"School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Junfeng","family":"Cheng","sequence":"additional","affiliation":[{"name":"School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yuting","family":"Chen","sequence":"additional","affiliation":[{"name":"School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Weiping","family":"Liu","sequence":"additional","affiliation":[{"name":"School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China"},{"name":"Engineering Research Center of Ministry of Education for Carbon Emission Reduction in Metal Resource Exploitation and Utilization, Central South University, Changsha 410083, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Wei","family":"Sun","sequence":"additional","affiliation":[{"name":"School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China"},{"name":"Engineering Research Center of Ministry of Education for Carbon Emission Reduction in Metal Resource Exploitation and Utilization, Central South University, Changsha 410083, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shafiq","family":"Alam","sequence":"additional","affiliation":[{"name":"Department of Chemical and Biological Engineering, College of Engineering, University of Saskatchewan, Saskatoon, SK S7N 5A9, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,4,11]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"747","DOI":"10.1080\/08827508.2021.1937150","article-title":"High purity alumina\u2014Current and future production","volume":"43","author":"Smith","year":"2021","journal-title":"Miner. Process. Extr. Metall. Rev."},{"key":"ref_2","first-page":"59","article-title":"Sludge formation in Hall\u2013H\u00e9roult Cells: Drawbacks and significant parameters","volume":"41","author":"Landry","year":"2018","journal-title":"Miner. Process. Extr. Metall. Rev."},{"key":"ref_3","unstructured":"Liu, W., Peng, Z., Zhao, Y., Cheng, J., Ngoie, M.K., and Sun, W. (2024). A Method for Precise Separation and Enhanced Leaching of Waste Barrier Material. (CN118685625A)."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"89","DOI":"10.1016\/j.wasman.2021.08.011","article-title":"A novel approach for lithium recovery from waste lithium-containing aluminum electrolyte by a roasting-leaching process","volume":"134","author":"Wu","year":"2021","journal-title":"Waste Manag."},{"key":"ref_5","first-page":"50","article-title":"Progress in resource utilization technology of aluminum electrolysis spent pot lining","volume":"03","author":"Li","year":"2022","journal-title":"Mining Metall."},{"key":"ref_6","first-page":"166","article-title":"Progress in comprehensive utilization of carbonaceous solid waste from aluminum electrolysis cells","volume":"01","author":"Liu","year":"2021","journal-title":"Conserv. Util. Miner. Resour."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"109508","DOI":"10.1016\/j.cep.2023.109508","article-title":"A novel approach for ultrasonic assisted organic acid leaching of waste lithium-containing aluminum electrolyte and recovery of lithium","volume":"192","author":"Yuan","year":"2023","journal-title":"Chem. Eng. Process."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"14537","DOI":"10.1021\/acs.iecr.3c01838","article-title":"Clean process for selective recovery of lithium carbonate from waste lithium-bearing aluminum electrolyte Slag","volume":"62","author":"Rui","year":"2023","journal-title":"Ind. Eng. Chem. Res."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"105505","DOI":"10.1016\/j.hydromet.2020.105505","article-title":"Novel process for the extraction of lithium carbonate from spent lithium-containing aluminum electrolytes by leaching with aluminum nitrate and nitric acid","volume":"198","author":"Wu","year":"2020","journal-title":"Hydrometallurgy"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"140800","DOI":"10.1016\/j.jclepro.2024.140800","article-title":"Efficient lithium recovery from electrolytic aluminum slag via an environmentally friendly process: Leaching behavior and mechanism","volume":"439","author":"Cui","year":"2024","journal-title":"J. Clean. Prod."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"110948","DOI":"10.1016\/j.jece.2023.110948","article-title":"Efficient lithium recovery from lithium-containing spent aluminium electrolyte via NaF fluorination roasting and Al2 (SO4) 3 leaching","volume":"5","author":"Han","year":"2023","journal-title":"J. Environ. Chem. Eng."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"107070","DOI":"10.1016\/j.resconrec.2023.107070","article-title":"Efficient extraction and recovery of lithium from waste aluminum cryolite electrolyte","volume":"197","author":"Tang","year":"2023","journal-title":"Resour. Conserv. Recycl."},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Karimi, Z., and Rahbar-Kelishami, A. (2023). Efficient utilization of red mud waste via stepwise leaching to obtain \u03b1-hematite and mesoporous \u03b3-alumina. Sci. Rep., 13.","DOI":"10.1038\/s41598-023-35753-w"},{"key":"ref_14","first-page":"11","article-title":"Research progress of lithium recovery from waste aluminum electrolyte containing lithium","volume":"5","author":"Wang","year":"2024","journal-title":"Metal World"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"566","DOI":"10.2138\/am-2002-0421","article-title":"A new polymorph of eucryptite (LiAlSiO4), \u03b5-eucryptite, and thermal expansion of \u03b1-and \u03b5-eucryptite at high pressure","volume":"87","author":"Zhang","year":"2002","journal-title":"Am. Mineral."},{"key":"ref_16","first-page":"64","article-title":"Main geological features and genesis of lacustrine sedimentary clay\u2212type lithium ores","volume":"43","author":"Wang","year":"2024","journal-title":"Miner. Rock Geochem. Bull."},{"key":"ref_17","first-page":"386","article-title":"Chemical equilibrium in silicate systems: Part II Reaction thermodynamics","volume":"03","author":"Ma","year":"2006","journal-title":"Geoscience"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"137229","DOI":"10.1016\/j.jclepro.2023.137229","article-title":"Recovery of fluoride from spent cathode carbon block by combustion combined with water leaching process","volume":"408","author":"Zhu","year":"2023","journal-title":"J. Clean. Prod."},{"key":"ref_19","unstructured":"Hao, P. (2019). Study on Reaction Mechanism of Dry Barrier Material of Aluminium Reduction Cell. [Ph.D. Thesis, Northeastern University]."},{"key":"ref_20","first-page":"2105","article-title":"Nondestructive identification of mineral inclusions by raman mapping: Micro-magnetite inclusions in iridescent scapolite as example","volume":"41","author":"Ye","year":"2021","journal-title":"Spectrosc. Spectr. Anal."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"182","DOI":"10.1016\/j.seppur.2007.10.012","article-title":"Recovery of fluoride values from spent pot-lining: Precipitation of an aluminium hydroxyfluoride hydrate product","volume":"61","author":"Lisbona","year":"2008","journal-title":"Sep. Purif. Technol."},{"key":"ref_22","first-page":"1240","article-title":"Application of IR spectra to the study of comprehensive utilization of fly ash","volume":"08","author":"Wang","year":"2005","journal-title":"Spectrosc. Spectr. Anal."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"57","DOI":"10.1346\/CCMN.2013.0610105","article-title":"Spectral and hydration properties of allophane and imogolite","volume":"61","author":"Janice","year":"2013","journal-title":"Clays Clay Miner."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"219","DOI":"10.1016\/j.micromeso.2015.06.027","article-title":"Synthesis and characterization of micro-mesoporous MCM-41 using various ionic liquids as co-templates","volume":"217","author":"Haleh","year":"2015","journal-title":"Microporous Mesoporous Mater."},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Ellerbrock, R., Stein, M., and Schaller, J. (2022). Comparing amorphous silica, short-range-ordered silicates, and silicic acid species by FTIR. Sci. Rep., 12.","DOI":"10.1038\/s41598-022-15882-4"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"115032","DOI":"10.1016\/j.envpol.2020.115032","article-title":"Formation and properties of inorganic Si-contaminant compounds","volume":"265","author":"Stein","year":"2020","journal-title":"Environ. Pollut."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"119722","DOI":"10.1016\/j.jnoncrysol.2019.119722","article-title":"Spectral changes in Si\u2013O\u2013Si stretching band of porous glass network upon ingress of water","volume":"527","author":"Kaya","year":"2020","journal-title":"J. Non-Cryst. Solids"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"5870","DOI":"10.1007\/s10853-006-0325-z","article-title":"Influence of thermal treatment on the water release and the glassy structure of perlite","volume":"41","author":"Roulia","year":"2006","journal-title":"J. Mater. Sci."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"e3023","DOI":"10.1002\/apj.3023","article-title":"An efficient and template-free synthesis of mesoporous silica from coal fly ash","volume":"19","author":"Liu","year":"2024","journal-title":"Asia-Pac. J. Chem. Eng."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"3591","DOI":"10.1016\/j.apsusc.2007.11.046","article-title":"Polymer adsorption on the surface of highly dispersed silica","volume":"254","author":"Walkowiak","year":"2008","journal-title":"Appl. Surf. Sci."},{"key":"ref_31","first-page":"20","article-title":"Surface adsorption of polyethylene glycol and polyvinyl alcohol with variable molecular weights on zinc oxide nanoparticles","volume":"8","author":"Nabiyouni","year":"2011","journal-title":"Iran. J. Chem. Chem. Eng."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"123960","DOI":"10.1016\/j.colsurfa.2019.123960","article-title":"Surfactant concentration and pH Effects on the zeta potential values of alumina nanofluids to inspect stability","volume":"583","author":"Cacua","year":"2019","journal-title":"Colloids Surf. A."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"108898","DOI":"10.1016\/j.mineng.2024.108898","article-title":"Efficient extraction of Li and Rb from zinnwaldite via thermal activation and acid leaching","volume":"216","author":"Zhong","year":"2024","journal-title":"Miner. Eng."}],"container-title":["Materials"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1996-1944\/18\/8\/1748\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,9]],"date-time":"2025-10-09T17:12:32Z","timestamp":1760029952000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1996-1944\/18\/8\/1748"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,4,11]]},"references-count":33,"journal-issue":{"issue":"8","published-online":{"date-parts":[[2025,4]]}},"alternative-id":["ma18081748"],"URL":"https:\/\/doi.org\/10.3390\/ma18081748","relation":{},"ISSN":["1996-1944"],"issn-type":[{"value":"1996-1944","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,4,11]]}}}