{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,10]],"date-time":"2026-10-10T04:03:56Z","timestamp":1791605036377,"version":"4.3.4"},"reference-count":28,"publisher":"MDPI AG","issue":"18","license":[{"start":{"date-parts":[[2026,9,19]],"date-time":"2026-09-19T00:00:00Z","timestamp":1789776000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["52174314"],"award-info":[{"award-number":["52174314"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"award":["52174314"],"award-info":[{"award-number":["52174314"]}],"id":[{"id":"https:\/\/ror.org\/01h0zpd94","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Molecules"],"abstract":"<jats:p>Vanadium-bearing steel slag has attracted considerable attention as a secondary source of vanadium. Pre-decalcified vanadium-bearing steel slag served as the feedstock to evaluate vanadium leaching under microwave irradiation and conventional water-bath heating by varying sulfuric acid concentration, temperature, leaching time, and liquid-to-solid ratio. The leaching performance was further evaluated through countercurrent leaching experiments, and kinetic analysis was conducted to investigate the rate-controlling behavior. The results demonstrated that the optimum leaching conditions under microwave irradiation were a liquid-to-solid ratio of 8 mL\u00b7g\u22121, a leaching time of 60 min, a sulfuric acid concentration of 15%, and a temperature of 70 \u00b0C, yielding a vanadium leaching rate of 74.43%. Multistage leachate reuse increased the normalized V enrichment index from 74.43% after the initial single-stage leaching to 89.93% after two reuse stages, with only a limited further increase thereafter. Kinetic analysis indicated a constant-particle-size shrinking-core mechanism for vanadium leaching. Sulfuric acid concentration exhibited an apparent reaction order of 1.80, and the apparent activation energy was 57.20 kJ\u00b7mol\u22121. Internal diffusion was identified as the predominant rate-controlling step, while the contribution of the interfacial chemical reaction could not be neglected. Microwave irradiation enhanced vanadium extraction through volumetric and selective heating effects, potentially promoting structural disruption of the pre-decalcified slag and facilitating leaching agent diffusion into the particle interior. These findings provide an effective hydrometallurgical strategy for sustainable vanadium recovery from industrial solid waste.<\/jats:p>","DOI":"10.3390\/molecules31183330","type":"journal-article","created":{"date-parts":[[2026,9,21]],"date-time":"2026-09-21T14:12:09Z","timestamp":1789999929000},"page":"3330","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Microwave-Assisted Sulfuric Acid Leaching of Vanadium from Pre-Decalcified Vanadium-Bearing Steel Slag"],"prefix":"10.3390","volume":"31","author":[{"ORCID":"https:\/\/orcid.org\/0009-0007-2988-0709","authenticated-orcid":false,"given":"Minhao","family":"Zhang","sequence":"first","affiliation":[{"name":"College of Metallurgy and Energy, North China University of Science and Technology, Tangshan 063210, China"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"conceptualization","vocabulary":"credit"},{"role":"data-curation","vocabulary":"credit"},{"role":"formal-analysis","vocabulary":"credit"},{"role":"methodology","vocabulary":"credit"},{"role":"investigation","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"},{"role":"writing-original-draft","vocabulary":"credit"},{"role":"visualization","vocabulary":"credit"}]},{"given":"Zekun","family":"Wang","sequence":"additional","affiliation":[{"name":"College of Metallurgy and Energy, North China University of Science and Technology, Tangshan 063210, China"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"conceptualization","vocabulary":"credit"},{"role":"methodology","vocabulary":"credit"},{"role":"resources","vocabulary":"credit"}]},{"given":"Ang","family":"Zhao","sequence":"additional","affiliation":[{"name":"College of Metallurgy and Energy, North China University of Science and Technology, Tangshan 063210, China"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"data-curation","vocabulary":"credit"},{"role":"visualization","vocabulary":"credit"}]},{"given":"Xuan","family":"Liu","sequence":"additional","affiliation":[{"name":"College of Metallurgy and Energy, North China University of Science and Technology, Tangshan 063210, China"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"conceptualization","vocabulary":"credit"},{"role":"methodology","vocabulary":"credit"}]},{"given":"Le","family":"Wang","sequence":"additional","affiliation":[{"name":"College of Metallurgy and Energy, North China University of Science and Technology, Tangshan 063210, China"},{"name":"Yanzhao Iron and Steel Laboratory, North China University of Science and Technology, 21 Bohai Street, Tangshan 063210, China"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"validation","vocabulary":"credit"},{"role":"methodology","vocabulary":"credit"},{"role":"funding-acquisition","vocabulary":"credit"},{"role":"resources","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"}]},{"given":"Jinglong","family":"Liang","sequence":"additional","affiliation":[{"name":"College of Metallurgy and Energy, North China University of Science and Technology, Tangshan 063210, China"},{"name":"Yanzhao Iron and Steel Laboratory, North China University of Science and Technology, 21 Bohai Street, Tangshan 063210, China"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"validation","vocabulary":"credit"}]}],"member":"1968","published-online":{"date-parts":[[2026,9,19]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"343","DOI":"10.1016\/j.jmrt.2021.02.065","article-title":"A review on the metallurgical recycling of vanadium from slags: Towards a sustainable vanadium production","volume":"12","author":"Lee","year":"2021","journal-title":"J. Mater. Res. Technol."},{"key":"ref_2","first-page":"37","article-title":"Annual Evaluation of Vanadium Industry in 2023","volume":"12","author":"Chen","year":"2024","journal-title":"Hebei Metall."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"4115","DOI":"10.1007\/s12598-024-02721-w","article-title":"A review on vanadium extraction techniques from major vanadium-containing resources","volume":"43","author":"Wang","year":"2024","journal-title":"Rare Met."},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Wang, M., Cai, L., Wen, J., Li, W., Yang, X., and Yang, H. (2023). The Prospect of Recovering Vanadium, Nickel, and Molybdenum from Stone Coal by Using Combined Beneficiation and Metallurgy Technology Based on Mineralogy Features. Minerals, 13.","DOI":"10.3390\/min13010021"},{"key":"ref_5","first-page":"2139","article-title":"Metal deportment in complex secondary raw materials: The case of vanadium in basic oxygen furnace slags","volume":"40","author":"Renno","year":"2023","journal-title":"Min. Metall. Explor."},{"key":"ref_6","first-page":"1307","article-title":"The recycling of vanadium from steelmaking slags: A review","volume":"9","author":"Shyrokykh","year":"2023","journal-title":"J. Sustain. Metall."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"124","DOI":"10.1016\/j.hydromet.2015.06.003","article-title":"Asynchronous extraction of vanadium and chromium from vanadium slag by stepwise sodium roasting-water leaching","volume":"156","author":"Li","year":"2015","journal-title":"Hydrometallurgy"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1068","DOI":"10.1016\/j.jclepro.2017.02.177","article-title":"Cleaner and effective process for extracting vanadium from vanadium slag by using an innovative three-phase roasting reaction","volume":"149","author":"Ji","year":"2017","journal-title":"J. Clean. Prod."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"103313","DOI":"10.1016\/j.jece.2019.103313","article-title":"A literature review on leaching and recovery of vanadium","volume":"7","author":"Peng","year":"2019","journal-title":"J. Environ. Chem. Eng."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"106313","DOI":"10.1016\/j.hydromet.2024.106313","article-title":"Review of leaching, separation and recovery of vanadium from roasted products of vanadium slag","volume":"226","author":"Li","year":"2024","journal-title":"Hydrometallurgy"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"402","DOI":"10.1016\/j.jallcom.2018.01.201","article-title":"Phase evolutions, microstructure and reaction mechanism during calcification roasting of high chromium vanadium slag","volume":"742","author":"Jiang","year":"2018","journal-title":"J. Alloys Compd."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"281","DOI":"10.1080\/00084433.2017.1327501","article-title":"Extraction of vanadium from direct acid leach solution of converter vanadium slag","volume":"56","author":"Zhang","year":"2017","journal-title":"Can. Metall. Q."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"1170","DOI":"10.1021\/cr4002353","article-title":"Modern microwave methods in solid-state inorganic materials chemistry: From fundamentals to manufacturing","volume":"114","author":"Kitchen","year":"2014","journal-title":"Chem. Rev."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"45","DOI":"10.1016\/j.hydromet.2018.11.004","article-title":"Effect of microwave heating on the pressure leaching of vanadium from converter slag","volume":"184","author":"Tian","year":"2019","journal-title":"Hydrometallurgy"},{"key":"ref_15","first-page":"448","article-title":"Treatment of blast furnace sludge (BFS) using a microwave heating technique","volume":"126","author":"Omran","year":"2017","journal-title":"Ironmak. Steelmak."},{"key":"ref_16","first-page":"1","article-title":"A kinetics study of multi-stage counter-current circulation acid leaching of vanadium from stone coal","volume":"114","author":"Zhu","year":"2012","journal-title":"Int. J. Miner. Process"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"542","DOI":"10.1007\/s11015-020-01025-5","article-title":"Counterflow leaching technology for vanadium from vanadium pentoxide hydrometallurgical production slurry","volume":"64","author":"Kologrieva","year":"2020","journal-title":"Metallurgist"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"520","DOI":"10.1016\/j.powtec.2018.09.045","article-title":"Change in phase, microstructure, and physical-chemistry properties of high chromium vanadium slag during microwave calcification-roasting process","volume":"340","author":"Gao","year":"2018","journal-title":"Powder Technol."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"6859","DOI":"10.1039\/C9RA00009G","article-title":"Microwave absorption properties of steelmaking dusts: Effects of temperature on the dielectric constant (\u03b5\u2032) and loss factor (\u03b5\u2033) at 1064 MHz and 2423 MHz","volume":"9","author":"Omran","year":"2019","journal-title":"RSC Adv."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"11515","DOI":"10.1021\/acs.est.4c14658","article-title":"Impact of electromagnetic fields on gypsum and silica scaling in reverse osmosis","volume":"59","author":"Du","year":"2025","journal-title":"Environ. Sci. Technol."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"121801","DOI":"10.1016\/j.jclepro.2020.121801","article-title":"Co-preparation of calcium sulfoaluminate cement and sulfuric acid through mass utilization of industrial by-product gypsum","volume":"265","author":"Wu","year":"2020","journal-title":"J. Clean. Prod."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"133183","DOI":"10.1016\/j.cej.2021.133183","article-title":"A review of microwave-assisted process intensified multiphase reactors","volume":"430","author":"Goyal","year":"2022","journal-title":"Chem. Eng. J."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"62","DOI":"10.1016\/j.hydromet.2003.07.011","article-title":"Shrinking core models in hydrometallurgy: What students are not being told about the pseudo-steady approximation","volume":"79","author":"Liddell","year":"2005","journal-title":"Hydrometallurgy"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"3193","DOI":"10.1007\/s10163-024-02040-3","article-title":"Recycling of Ni from leached spent catalyst residue by H2SO4 leaching and solvent extraction: Leaching kinetics, purification and product preparation","volume":"26","author":"Liu","year":"2024","journal-title":"J. Mater. Cycles Waste Manag."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"105195","DOI":"10.1016\/j.jece.2021.105195","article-title":"Vanadium extraction from roasted vanadium-bearing steel slag via pressure acid leaching","volume":"9","author":"Liu","year":"2021","journal-title":"J. Environ. Chem. Eng."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"2717","DOI":"10.1016\/j.apsusc.2010.10.051","article-title":"Resolving surface chemical states in XPS analysis of first row transition metals, oxides and hydroxides","volume":"257","author":"Biesinger","year":"2011","journal-title":"Appl. Surf. Sci."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"986","DOI":"10.1107\/S1600577525003868","article-title":"A microfocus study on basic-oxygen-furnace slag thin sections to understand the principles of vanadium incorporation","volume":"32","author":"Wunderlich","year":"2025","journal-title":"J. Synchrotron Radiat."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"887","DOI":"10.1016\/j.apsusc.2010.07.086","article-title":"Resolving surface chemical states in XPS analysis of first row transition metals, oxides and hydroxides: Sc, Ti, V, Cu and Zn","volume":"257","author":"Biesinger","year":"2010","journal-title":"Appl. Surf. 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