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Minerals, Volume 15, Issue 3 (March 2025) – 132 articles

Cover Story (view full-size image): The Walton carbonate-replacement Ag-Pb-Zn-Cu sulphide deposit consists of a finely crystalline massive baryte body overlying a siderostone-hosted sulphide body. The siderostone formed due to dissimilatory iron reduction (DIR) that led to the breakdown of Fe–Mn oxyhydroxides and organic matter, whereas the massive baryte body likely resulted from the mixing of sulphate-rich and Ba-rich fluid reservoirs. Siderite and baryte are abundant in many sedimentary rock-hosted sulphide deposits; therefore, their origin is essential to understanding the genesis of the deposit. View this paper
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37 pages, 14137 KiB  
Article
Origin of Siderite and Baryte in a Carbonate-Replacement Ag-Pb-Zn-Cu Sulphide Deposit: Walton, Nova Scotia, Canada
by Chaneil J. Wallace, Daniel J. Kontak, Elizabeth C. Turner and Mostafa Fayek
Minerals 2025, 15(3), 327; https://doi.org/10.3390/min15030327 - 20 Mar 2025
Viewed by 536
Abstract
Siderite and baryte are common non-sulphide phases in sedimentary exhalative (SEDEX) deposits, but their formation remains poorly understood. Siderite is important as an exploration vector in some deposits, whereas baryte is important as a S source in some deposits. The past-producing Walton deposit [...] Read more.
Siderite and baryte are common non-sulphide phases in sedimentary exhalative (SEDEX) deposits, but their formation remains poorly understood. Siderite is important as an exploration vector in some deposits, whereas baryte is important as a S source in some deposits. The past-producing Walton deposit (Nova Scotia, Canada) consists of two ore types: (1) a sulphide body primarily hosted by sideritised Viséan Macumber Formation limestone (0.41 Mt; head grade of 350 g/t Ag, 4.28% Pb, 1.29% Zn, and 0.52% Cu), and (2) an overlying massive baryte body of predominantly microcrystalline baryte (4.5 Mt of >90% baryte). This study used optical microscopy, SEM-EDS, cathodoluminescence (CL), LA-ICP-MS, and SIMS sulphur isotope analysis of siderite and baryte to elucidate their origin and role in deposit formation. Siderite replaces limestone and contains ≤9 wt. % Mn, is LREE-depleted (PAAS-normalised REEY diagrams), and has low (<20) Y/Ho ratios. Sideritisation occurred due to dissimilatory iron reduction (DIR) that led to the breakdown of Fe-Mn-oxyhydroxides and organic matter, as indicated by light δ13CVPBD values and negative Y anomalies. The baryte body is dominated by a microcrystalline variety that locally develops a radial texture and coarsens to a tabular variety; it also occurs intergrown with, and as veins in, massive sulphides. Based on fluid inclusion data from previous studies, the coarser baryte types grew from a hot (>200 °C) saline (25 wt. % NaCl) fluid containing CO2-CH4 and liquid petroleum. Marine sulphate δ34SVCDT values typical of the Viséan (~15‰) characterise the baryte body and some tabular baryte types, whereas heavier (~20‰) and lighter (~10‰) values typify the remaining tabular types. The variations in tabular baryte relate to distinct zones identified by CL imaging and are attributed to the sulphate-driven anaerobic oxidation of methane (SDAOM) and oxidation of excess H2S after sulphide precipitation. These results highlight the importance of hydrocarbons (methane and organic matter) in the formation of both the siderite and the baryte at Walton and that DIR and the SDAOM can be important contributing processes in the formation of SEDEX deposits. Full article
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20 pages, 9535 KiB  
Article
Hydrothermal Retrogradation from Chlorite to Tosudite: Effect on the Optical Properties
by Zahra Ahmadi, Fernando Nieto, Farhad Khormali, Nicolás Velilla, Morteza Einali, Abbas Maghsoudi and Arash Amini
Minerals 2025, 15(3), 326; https://doi.org/10.3390/min15030326 - 20 Mar 2025
Viewed by 289
Abstract
In the argillic alteration zone of the SinAbad area of the Urumieh–Dokhtar magmatic belt (Iran), Mg-rich, Fe-poor chlorites, which crystallised at temperatures between 160 °C and 260 °C, were affected by extensive alteration to smectite mixed-layering at the micro- and nano-scales during the [...] Read more.
In the argillic alteration zone of the SinAbad area of the Urumieh–Dokhtar magmatic belt (Iran), Mg-rich, Fe-poor chlorites, which crystallised at temperatures between 160 °C and 260 °C, were affected by extensive alteration to smectite mixed-layering at the micro- and nano-scales during the retrograde evolution of the hydrothermal system. Chlorites retain their usual optical aspect and properties, except for the index of refraction perpendicular to the (001) layers, which becomes lower than those parallel to the layers, producing an increase in birefringence and change in the optic and elongation signs, in comparison to the ordinary ones for Mg chlorites. Scanning electron microscopy (SEM) maps and compositions, and electron microprobe (EMP) analyses indicate minor but ubiquitous Ca (and K) content. X-ray diffraction (XRD) of chloritic concentrates allowed the identification of chlorite and tosudite. High-resolution transmission electron microscopy (HRTEM) images show major 14 Å (chlorite), with the frequent presence of 24 Å (contracted tosudite) individual layers and small packets up to five layers thick. Lateral change from 14 Å to 24 Å individual layers has been visualised. High-resolution chemical maps obtained in high-angle annular dark-field (HAADF) mode confirm the existence of areas preferentially dominated by chlorite or tosudite. The overall chemical compositions obtained by SEM, EMP, and transmission electron microscopy (TEM) align from the chlorite to the tosudite end-members, whose pure compositions could be determined from extreme analytical electron microscopy (AEM) analyses. The described intergrowths and interlayers, under the optical resolution, could provide a clue to explain changes in the normal optic properties of chlorite, which are mentioned, but not explained, in the literature. Full article
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21 pages, 13959 KiB  
Article
Utilisation of Zinc Processing Tailings (ZPTs) in Fired Clay Bricks Manufacturing: Case Study
by Ali Messai, Juan M. Menéndez-Aguado, Linda Berrekbia, Ikram Meramria, Begoña Fernández Pérez, Vladimir Nikolić, Milan Trumić and Amir Boustila
Minerals 2025, 15(3), 325; https://doi.org/10.3390/min15030325 - 20 Mar 2025
Viewed by 399
Abstract
Zinc processing tailings (ZPTs) of the Kharzet Youcef processing complex, Setif, Algeria, are mainly stockpiled in tailing dumps without use, occupying significant surfaces and negatively influencing the human environment and health. Incorporating ZPTs into building materials manufacturing is an effective solution to meet [...] Read more.
Zinc processing tailings (ZPTs) of the Kharzet Youcef processing complex, Setif, Algeria, are mainly stockpiled in tailing dumps without use, occupying significant surfaces and negatively influencing the human environment and health. Incorporating ZPTs into building materials manufacturing is an effective solution to meet the dual objectives of environmental protection and economic development. This study investigates the influence of firing temperature and integrating ZPTs as a partial replacement for clay on the physic-mechanical properties of fired clay bricks (FCBs). Microstructural, chemical, and mineralogical analyses of ZPTs and clay were carried out by SEM-EDS, XRF, and XRD, respectively. Seven mixtures were produced with various percentages of ZPTs added to clay (0%, 5%, 10%, 15%, 20%, 25%, and 30%) and were fired at two different temperatures (900 and 1000 °C) at a ramp rate of 5 °C. Physic-mechanical tests were carried out on different brick specimens, and the results obtained showed that the FCBs incorporated with 10% of ZPTs produced the highest flexural strength of 6.24 MPa, compressive resistance of 29.78 MPa, bulk density of 1.37 g/cm3, and water absorption of 15.1% at 900 °C. Therefore, the recycling of ZPTs for FCBs manufacturing is feasible and an effective alternative waste disposal solution for sustainable development while reducing negative environmental impacts. Full article
(This article belongs to the Special Issue Mineral Processing and Recycling Technologies for Sustainable Future)
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43 pages, 41722 KiB  
Article
Massive Dolomitization of Interior and Slope to Basin-Margin Facies of the Triassic Yangtze Platform Through Superposed Earth-Surface and Burial Mechanisms, Nanpanjiang Basin, South China
by Nathaniel S. Ledbetter Ferrill, Xiaowei Li, Josephine Tesauro, Madison Sears, George M. Bradley, Arianna Hilbert, Eryn Carney, Justice Saxby, Neda Mobasher, Brian M. Kelley, E. Troy Rasbury, Kathleen M. Wooton, Jason D. Kirk, John A. Luczaj and Daniel J. Lehrmann
Minerals 2025, 15(3), 324; https://doi.org/10.3390/min15030324 - 19 Mar 2025
Viewed by 523
Abstract
Triassic strata of the Yangtze Platform at Guanling contain a dolomitized interior, undolomitized margin, and partially dolomitized slope to basin margin. Dolomitized microbial laminate caps of peritidal cycles and massive dolomite with associated evaporite nodules and solution collapse breccias are consistent with penecontemporaneous [...] Read more.
Triassic strata of the Yangtze Platform at Guanling contain a dolomitized interior, undolomitized margin, and partially dolomitized slope to basin margin. Dolomitized microbial laminate caps of peritidal cycles and massive dolomite with associated evaporite nodules and solution collapse breccias are consistent with penecontemporaneous tidal flat and evaporative dolomitization in the platform interior. The preferential dolomitization of the slope and basin margin (up to 7 km basinward of the margin), dolomitization along fractures, and selective dolomitization of the matrix in slope breccia that diminishes toward the margin are interpreted to have resulted from the incursion of basin-derived fluids during burial. Integrated analysis of fluid-inclusion microthermometry, oxygen, carbon, and strontium isotopes, trace element geochemistry, U-Pb age dates of carbonate phases, and burial history support the recrystallization of interior dolomite and slope to basin-margin dolomitization by brines at high temperatures during burial. The Yangtze Platform at Guanling provides an excellent example of widespread stratiform dolomitization resulting from the superposition of multiple mechanisms, including penecontemporaneous dolomitization by evaporative seawater brines, high-temperature dolomitization of the slope and basin margin by basinal brines, and high-temperature recrystallization of dolomite by brines during burial. This study provides an example that suggests that widespread stratiform dolomite may result from superposed Earth surface and high-temperature burial dolomitization processes and provides a valuable analog for other carbonate platforms in which the margin remains undolomitized while the interior and basin margin are dolomitized. Similar mechanisms likely contributed to the widespread dolomitization of platforms across the Nanpanjiang and Sichuan basins. Full article
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17 pages, 8607 KiB  
Article
Leaching Behavior of Waste Barrier Material with Sulfuric Acid
by Saiya Li, Yujie Zhao, Junfeng Cheng, Yuting Chen, Weiping Liu and Wei Sun
Minerals 2025, 15(3), 323; https://doi.org/10.3390/min15030323 - 19 Mar 2025
Viewed by 267
Abstract
The comprehensive recycling of aluminum electrolysis cell waste barrier material is urgent. This study focuses on the sulfuric acid leaching of waste barrier material, systematically examining the effects of factors such as reaction temperature, liquid-to-solid ratio, sulfuric acid concentration, and reaction time on [...] Read more.
The comprehensive recycling of aluminum electrolysis cell waste barrier material is urgent. This study focuses on the sulfuric acid leaching of waste barrier material, systematically examining the effects of factors such as reaction temperature, liquid-to-solid ratio, sulfuric acid concentration, and reaction time on the leaching of elements like lithium, aluminum, sodium, and silicon. The experimental results show that under the conditions of 0.9 mol/L sulfuric acid concentration, a liquid-to-solid ratio of 20:1, a reaction temperature of 90 °C, and a reaction time of 1.5 h, the leaching rates were 84.5% for lithium, 85.6% for aluminum, 98.5% for sodium, and 4.8% for silicon. The sulfuric acid leaching process of the waste barrier material follows a shrinking core model and is controlled by internal diffusion. The apparent activation energies for the leaching reactions of lithium, aluminum, and sodium were 4.29 kJ/mol, 8.99 kJ/mol, and 9.11 kJ/mol, respectively. The selective leaching of lithium, sodium, and aluminum from silicon was successfully achieved in the sulfuric acid leaching of the waste barrier material. Full article
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48 pages, 88667 KiB  
Article
Biomineralization in the Calcareous Nannoplankton Phenotypic Expressions Across Life Cycles, Geometric Control on Diversification, and Origin
by Marie-Pierre Aubry
Minerals 2025, 15(3), 322; https://doi.org/10.3390/min15030322 - 19 Mar 2025
Viewed by 436
Abstract
The calcareous nannoplankton comprises haptophyte eukaryotes known as coccolithophores, capable of calcifying elaborate external skeletons (coccoliths s.l.) which differ morphologically depending on the phase of the life cycle considered, and the locus (intra- or extracellular) of mineralization. No study is currently available that [...] Read more.
The calcareous nannoplankton comprises haptophyte eukaryotes known as coccolithophores, capable of calcifying elaborate external skeletons (coccoliths s.l.) which differ morphologically depending on the phase of the life cycle considered, and the locus (intra- or extracellular) of mineralization. No study is currently available that analyzes the impact of these differences on coccolith morphology. An analysis of the assembly of their crystals is conducted here in search of the following: (1) identical traits across life cycles; (2) fossil records diagnostic of extracellular calcification; and (3) influence of the geometry of biomineralization during the diploid phase on the long-term evolution of a clade. This study shows patterns such as correlation of characters and structural imprint that unify the haploid and diploid phases, indicating a strong cellular integrity and offering potent means to determine life cycles in living and fossil communities. It also shows that differences in diversity patterns and longevity among families and orders depend on coccolith geometry, concentric geometry being more favorable to stability, and superposition geometry facilitating morphological diversification. Extinction occurs when the potential for diversification is attained. Finally, I propose that the evolution of biomineralization in the calcareous nannoplankton may have been more complex than initially thought, with intra- and extracellular calcification evolving independently. Full article
(This article belongs to the Section Biomineralization and Biominerals)
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26 pages, 8606 KiB  
Article
Chronology and Petrogenesis of the Yangjiayu Complex from Eastern China: Evidence from Zircon U–Pb Dating, Hf Isotopes, and Geochemical Characteristics
by Huiji Zhao, Yanchao Han, Yinan Liu, Guangzhou Mao, Lei Chen, Yuanyuan Cui, Yang Liu, Yongming Liu, Quanguo Jiang and Lili Wang
Minerals 2025, 15(3), 321; https://doi.org/10.3390/min15030321 - 19 Mar 2025
Viewed by 239
Abstract
This study examines the origin, tectonic setting, and Cu–Pb–Zn polymetallic mineralization of the Yangjiayu Complex, situated on the southwestern margin of the Jiaolai Basin. We present detailed geochemical, zircon U–Pb geochronological, and Hf isotopic data for rhyolite porphyry and monzodiorite samples. Zircon U–Pb [...] Read more.
This study examines the origin, tectonic setting, and Cu–Pb–Zn polymetallic mineralization of the Yangjiayu Complex, situated on the southwestern margin of the Jiaolai Basin. We present detailed geochemical, zircon U–Pb geochronological, and Hf isotopic data for rhyolite porphyry and monzodiorite samples. Zircon U–Pb dating reveals that the emplacement of both intrusions occurred in the Early Cretaceous. While the monzodiorite (122.5 ± 0.7 Ma) is numerically slightly older than the rhyolite porphyry (121.2 ± 0.6 Ma), considering the error ranges, their ages are essentially similar. The rhyolite porphyry displays higher SiO2 and Na2O + K2O contents and a lower Al2O3 content relative to the monzodiorite. Geochemically, both intrusions are classified as high-K calc-alkaline and peraluminous, characterized by enrichment in large-ion lithophile elements (LILEs; e.g., Ba, Rb, Pb) and light rare earth elements (LREEs), along with depletion in high-field-strength elements (HFSEs; e.g., Nb, P, Ta) and heavy rare earth elements (HREEs). The rhyolite porphyry further exhibits middle rare earth elements (MREEs; e.g., Eu, Gd, Tb, Dy) depletion. Similar zircon εHf(t) values (monzodiorite: −23.0 to −26.1; rhyolite porphyry: −23.2 to −25.0) suggest a shared source derived from partial melting of the thickened lower crustal rocks. In comparison to the monzodiorite, the rhyolite porphyry shows lower total REE contents, a more pronounced negative Eu anomaly and stronger MREE depletion, higher Rb, Th, and U concentrations, and more significant P depletion, features indicative of more extensive assimilation-fractional crystallization (AFC). These geochemical and geochronological data indicate that the Yangjiayu Complex originated within an extensional tectonic setting associated with the Early Cretaceous subduction of the Paleo-Pacific Plate underneath the Eurasian Plate. Cu–Pb–Zn mineralization, primarily localized within the monzodiorite, is interpreted to be generated by magmatic-hydrothermal fluids. Therefore, ~120 Ma dioritic intrusions within the Jiaolai Basin constitute prospective targets for (Cu)–Pb–Zn polymetallic exploration. Full article
(This article belongs to the Section Mineral Geochemistry and Geochronology)
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14 pages, 6070 KiB  
Article
The Uplift and Denudation History of the Jianfeng Pluton on Hainan Island, China
by Di Lin, Guicheng Xue, Yong Zheng, Gucheng Zhang, Zailong Hu, Changxin Wei, Zhizhuang Zhang and Qinmin Yuan
Minerals 2025, 15(3), 320; https://doi.org/10.3390/min15030320 - 19 Mar 2025
Viewed by 242
Abstract
Hainan Island is the only large island located on the northern margin of the South China Sea and is surrounded by Cenozoic graben basins, including the Qiongdongnan, Yinggehai, and Beibuwan basins. The uplift and denudation history of the Jianfeng pluton on southwestern Hainan [...] Read more.
Hainan Island is the only large island located on the northern margin of the South China Sea and is surrounded by Cenozoic graben basins, including the Qiongdongnan, Yinggehai, and Beibuwan basins. The uplift and denudation history of the Jianfeng pluton on southwestern Hainan Island is significant for understanding the formation of the regional geomorphology and adjacent basin evolution. This paper presents apatite and zircon fission-track (FT) analyses conducted on the Jianfeng pluton. The zircon FT (ZFT) ages of the pluton range are from 63 ± 4 to 108 ± 8 Ma, and the apatite FT (AFT) ages are from 19.4 ± 1.8 to 43.9 ± 4.4 Ma. The average confined track lengths in apatite are relatively short (11.9–12.8 μm). An age–elevation plot indicates that two rapid cooling events occurred during 73–63 and 44–40 Ma. Thermal modeling revealed four stages of 73–63 Ma, 44–40 Ma, 40–11 Ma, and 11–0 Ma. From the Late Cretaceous to the middle Eocene (73–40 Ma), the Jianfeng area underwent episodic rapid uplift and denudation. At the end of the Late Cretaceous (73–63 Ma), the area was affected by mid-ocean ridge spreading in the Proto-South China Sea. During the middle Eocene (44–40 Ma), the Yinggehai Basin underwent abrupt expansion and subsidence, which increased the elevation difference between the Jianfeng area and the Yinggehai Basin. From the middle Eocene to the middle Miocene (40–11 Ma), the Jianfeng area underwent slow denudation, and the Yinggehai Basin was rapidly infilled, which eliminated the original elevation difference between the two areas. From the middle Miocene to the present (11–0 Ma), the Jianfeng area has undergone reactivated rapid uplift and denudation, which was driven by the remote effects of the India–Eurasia collision. Full article
(This article belongs to the Special Issue Thermal History Modeling of Low-Temperature Thermochronological Data)
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26 pages, 28443 KiB  
Article
Diagenetic Evolution and Formation Mechanism of Middle to High-Porosity and Ultralow-Permeability Tuff Reservoirs in the Huoshiling Formation of the Dehui Fault Depression, Songliao Basin
by Siya Lin, Xiaobo Guo, Lili Li, Jin Gao, Song Xue, Yizhuo Yang and Chenjia Tang
Minerals 2025, 15(3), 319; https://doi.org/10.3390/min15030319 - 19 Mar 2025
Viewed by 313
Abstract
The fluid action mechanism and diagenetic evolution of tuff reservoirs in the Cretaceous Huoshiling Formation of the Dehui fault depression are discussed herein. The fluid properties of the diagenetic flow are defined, and the pore formation mechanism of the reservoir space is explained [...] Read more.
The fluid action mechanism and diagenetic evolution of tuff reservoirs in the Cretaceous Huoshiling Formation of the Dehui fault depression are discussed herein. The fluid properties of the diagenetic flow are defined, and the pore formation mechanism of the reservoir space is explained by means of thin sections, X-ray diffraction, electron probes, scanning electron microscopy (SEM), cathodoluminescence, and stable carbon and oxygen isotopic composition and fluid inclusion tests. The results reveal that the tuff reservoir of the Huoshiling Formation is moderately acidic, and the physical properties of the reservoir are characterized by middle to high porosity and ultralow permeability. The pore types are complex, comprising both primary porosity and secondary porosity, with dissolution pores and devitrification pores being the most dominant. Mechanical compaction and cementation are identified as key factors reducing reservoir porosity and permeability, while dissolution and devitrification processes improve pore structure and enhance pore connectivity. Diagenetic fluids encompass alkaline fluids, acidic fluids, deep-seated CO+-rich hydrothermal fluids, and hydrocarbon-associated fluids. These fluids exhibit dual roles in reservoir evolution: acidic fluids enhance the dissolution of feldspar, tuffaceous materials, and carbonate minerals to generate secondary pores and improve reservoir quality, whereas alkaline fluids induce carbonate cementation, and clay mineral growth (e.g., illite) coupled with late-stage mineral precipitation obstructs pore throats, reducing permeability. The interplay among multiple fluid types and their varying dominance at different burial depths collectively governs reservoir evolution. This study underscores the critical role of fluid–rock interactions in controlling porosity–permeability evolution within tuff reservoirs. Full article
(This article belongs to the Special Issue Element Enrichment and Gas Accumulation in Black Rock Series)
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23 pages, 4220 KiB  
Review
Utilization of Natural Mineral Materials in Environmental Remediation: Processes and Applications
by Di Xu, Yongkui Yang and Lingqun Gan
Minerals 2025, 15(3), 318; https://doi.org/10.3390/min15030318 - 19 Mar 2025
Viewed by 358
Abstract
The discharge of wastewater containing persistent organic pollutants presents significant ecological and health challenges due to their toxicity and resilience. Recent advances in advanced oxidation processes (AOPs) and other remediation mechanisms, notably utilizing natural mineral materials (NMMs), offer promising solutions to these challenges. [...] Read more.
The discharge of wastewater containing persistent organic pollutants presents significant ecological and health challenges due to their toxicity and resilience. Recent advances in advanced oxidation processes (AOPs) and other remediation mechanisms, notably utilizing natural mineral materials (NMMs), offer promising solutions to these challenges. NMMs, with their cost-effectiveness, accessibility, eco-friendly nature, non-toxicity, and unique structural properties, have shown significant promise in environmental remediation and could effectively replace conventional catalysts in related applications. These minerals enable the activation of oxidants, generating reactive oxygen species crucial for the degradation of pollutants. This article reviews the mechanisms of NMMs in various AOPs, including photocatalysis, Fenton-like reactions, and persulfate-activation-based processes, and discusses the potential of these materials in enhancing pollutant degradation efficiency, with a focus on the activation of persulfates and the photo-induced redox processes. The synergy between photocatalytic properties and catalytic activation provided by NMMs offers a robust approach to managing water pollution without the drawbacks of secondary waste production, thus supporting sustainable remediation efforts. Full article
(This article belongs to the Section Environmental Mineralogy and Biogeochemistry)
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31 pages, 16566 KiB  
Article
The Role of Fluid Chemistry in the Diagenetic Transformation of Detrital Clay Minerals: Experimental Insights from Modern Estuarine Sediments
by Anas Muhammad Salisu, Abdulwahab Muhammad Bello, Abduljamiu O. Amao and Khalid Al-Ramadan
Minerals 2025, 15(3), 317; https://doi.org/10.3390/min15030317 - 19 Mar 2025
Viewed by 409
Abstract
The diagenetic transformation of detrital clay minerals significantly influences sandstone reservoir quality, with fluid chemistry and temperature playing key roles in dictating transformation pathways during burial diagenesis. While these processes are well-documented in basinal settings, the diagenetic alterations of sediments in dynamic environments [...] Read more.
The diagenetic transformation of detrital clay minerals significantly influences sandstone reservoir quality, with fluid chemistry and temperature playing key roles in dictating transformation pathways during burial diagenesis. While these processes are well-documented in basinal settings, the diagenetic alterations of sediments in dynamic environments like estuaries remain underexplored. This study investigates the impact of fluid composition on the transformation of modern estuarine sediments through hydrothermal experiments using sediments from the Gironde estuary, SW France. A range of natural and synthetic solutions including seawater (SW), 0.1 M KCl (SF1), 0.1 M NaCl, KCl, CaCl2·2H2O, MgCl2·6H2O (SF2), estuarine water (EW), and 0.1 M Na2CO3 (SF3) were used under temperatures from 50 °C to 250 °C for 14 days, with a fixed fluid-to-sediment ratio of 10:1. The results revealed distinct mineralogical transformations driven by fluid composition. Dissolution of detrital feldspars and clay materials began at lower temperatures (<100 °C). The authigenic formation of smectite and its subsequent illitization in K-rich fluids (SW, SF1) occurred between 150 °C and 250 °C, replicating potassium-driven illitization processes observed in natural sandstones. Additionally, chlorite formation occurred through the conversion of smectite in SF2 and EW. Geochemical analysis showed that SF2 produced Mg-rich chlorites, while EW yielded Fe-rich chlorites. This aligns with diagenetic trends in coastal environments, where Fe-rich chlorites are typically associated with estuarine systems. The resulting authigenic illite and chlorite exhibited morphological and chemical characteristics similar to those found in natural sandstones, forming through dissolution-crystallization and solid-state transformation mechanisms. In contrast to illite and chlorite, SF3 produced entirely different mineral phases, including halite and analcime (zeolite), attributed to the high alkalinity and Na-rich composition of the solution. These findings provide valuable insights into the role of fluid chemistry in the diagenetic alteration of modern sediments and their implications for the evolution of sandstone reservoirs, which is critical for energy exploration and transition. Full article
(This article belongs to the Section Clays and Engineered Mineral Materials)
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27 pages, 46975 KiB  
Article
A Study of the Geochemical Characteristics of Tourmaline-Supergroup Minerals from the Bozhushan Composite Granite Body in Southeastern Yunnan
by Xianchao Chen, Liurunxuan Chen, Shitao Zhang, Xuelong Liu, Qiuyun Song, Linlong Sun, Ruohan Zuo, Bode Lu and Jiehu Zhou
Minerals 2025, 15(3), 316; https://doi.org/10.3390/min15030316 - 19 Mar 2025
Viewed by 288
Abstract
The Bozhushan in southeastern Yunnan is a composite granite body that was formed by multi-phase magmatic intrusion. The genesis of the tourmaline-supergroup minerals occurring therein remains uncertain, as it has been the subject of only a limited number of studies. This investigation employs [...] Read more.
The Bozhushan in southeastern Yunnan is a composite granite body that was formed by multi-phase magmatic intrusion. The genesis of the tourmaline-supergroup minerals occurring therein remains uncertain, as it has been the subject of only a limited number of studies. This investigation employs an integrated analytical approach combining EPMA, LA-ICP-MS, and boron isotope geochemistry, supplemented by detailed field geological investigations and petrographic observations of tourmaline textural characteristics. This study aims to elucidate the genetic relationships between distinct tourmaline varieties, establish temporal correlations between mineral crystallization stages and magmatic–hydrothermal evolution processes, and evaluate the petrogenetic significance of tourmaline geochemical signatures for regional mineralization events. This study analyzes tourmaline-supergroup minerals in granitic pegmatites and aplites, which occur as nodular, radial, and columnar aggregates. Most tourmaline crystals exhibit well-defined rhythmic zoning patterns, which are clearly observable under cross-polarized light microscopy. Chemical composition analysis has identified two tourmaline species: schorl and dravite. The formation of tourmaline is primarily of magmatic origin and is characterized by a magmatic–hydrothermal transition. It predominantly belongs to the alkali subgroup and is formed in Li-poor granitoids and associated pegmatites and aplites, Ca-poor metapelites, metapsammites, and quartz-tourmaline rocks. The inter-ionic substitution mechanism in this system is predominantly governed by Fe2+Mg−1 and (XvacAl)(NaR2+)−1 exchange equilibria. Additionally, geochemical evidence indicates that the primary ore-forming fluids originate from granitic magmas, which are likely sourced from the partial melting of metasedimentary rocks. During the late Yanshan period, the upwelling of granitic magma in the Bozhushan area introduced a substantial heat source and mineralizing fluids, which interacted with the Cambrian units to form tungsten–tin mineralization. The geochemical data on tourmaline indicate that the Bozhushan granite body has considerable potential for ore mineralization. Full article
(This article belongs to the Section Mineral Geochemistry and Geochronology)
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22 pages, 20086 KiB  
Article
Zircon LA-ICP-MS Dating and Geochemical Characteristics of Rhyolites from the Qushi Area, Tengchong Terrane, Yunnan Province
by Xiong Mo, Chen Gong, Yan Shang, Jinglong Wu, Jialin Wu, Ronghui Qi, Xiaofeng Wang, Qi Guan and Xu Kong
Minerals 2025, 15(3), 315; https://doi.org/10.3390/min15030315 - 18 Mar 2025
Viewed by 341
Abstract
The Qushi rhyolites, situated in the eastern sector of the Tengchong terrane, are critical to understanding the Early Cretaceous tectono-magmatic evolution of the Eastern Tethyan Tectonic Domain. Zircon LA-ICP-MS U-Pb geochronology indicates crystallization ages of 118.3–120.5 Ma, with Ti-in-zircon temperatures of 641–816 °C [...] Read more.
The Qushi rhyolites, situated in the eastern sector of the Tengchong terrane, are critical to understanding the Early Cretaceous tectono-magmatic evolution of the Eastern Tethyan Tectonic Domain. Zircon LA-ICP-MS U-Pb geochronology indicates crystallization ages of 118.3–120.5 Ma, with Ti-in-zircon temperatures of 641–816 °C (mean = 716 °C), representing the Early Cretaceous magmatic activity in the Tengchong terrane. Inherited zircons within the rhyolites yield a zircon age of ca. 198.5 Ma, with corresponding Ti-in-zircon temperatures of 615–699 °C (mean = 657 °C), implying the potential presence of an Early Jurassic igneous basement beneath the Qushi region. Geochemically, the rhyolites are classified as calc-alkaline and weakly to moderately peraluminous (A/CNK = 1.07–2.86). These rocks display signatures typical of acidic magmas, marked by significant enrichments in light rare earth elements (LREE: La and Ce) and large ion lithophile elements (LILE: Rb, K, Th and U) while simultaneously exhibiting depletions in high-field-strength elements (HFSE: Nb, Ta, Ti, and P) and heavy rare earth elements (HREE). Trace element signatures further reveal marked depletions in Sr (12.4–244.7 ppm) and Ba while displaying enrichments in Zr and Hf. These geochemical features, including the huge range of the Sr content and A/CNK ratios, suggest both I-type and S-type granite affinities. The Early Cretaceous volcanism of the Qushi rhyolites is likely attributed to the combined effects of subduction and the closure of the Meso-Tethyan Ocean (MTO). This volcanic activity is interpreted to result from subduction-related processes associated with the MTO, potentially involving slab rollback, slab break-off, and subsequent asthenospheric upwelling. The formation of these rhyolites may also be linked to the final closure of the MTO, characterized by the Late Cretaceous collision and amalgamation of the Burma and Tengchong terranes. Full article
(This article belongs to the Special Issue Tectonic Evolution of the Tethys Ocean in the Qinghai–Tibet Plateau)
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28 pages, 16980 KiB  
Article
Genesis of the Gongjuelong Sn Polymetallic Deposit in the Yidun Terrane, China: Constraints from the In Situ Geochemistry of Garnet, Cassiterite, and Quartz
by Yuchang Zhou, Yiwei Peng, Chang Liu, Jianji Tian, Zhi Wang, Mingwei Song and Yan Zhang
Minerals 2025, 15(3), 314; https://doi.org/10.3390/min15030314 - 18 Mar 2025
Viewed by 282
Abstract
Numerous skarn-type Sn and hydrothermal vein-type Pb–Zn–Ag deposits occur in the northern Yidun Terrane, China. The Gongjuelong skarn Sn polymetallic deposit, adjacent to the Haizishan granite, is situated in the central region of Yidun Terrane. The genesis of the Gongjuelong Sn deposit and [...] Read more.
Numerous skarn-type Sn and hydrothermal vein-type Pb–Zn–Ag deposits occur in the northern Yidun Terrane, China. The Gongjuelong skarn Sn polymetallic deposit, adjacent to the Haizishan granite, is situated in the central region of Yidun Terrane. The genesis of the Gongjuelong Sn deposit and its relationship with the adjacent Pb–Zn–Ag deposits remains controversial. The ore-forming process can be divided into three stages: the prograde stage (I), marked by the formation of garnet and pyroxene; the retrograde stage (II), which includes the epidote–actinolite sub-stage (II-1) and the quartz-cassiterite sub-stage (II-2); and the sulfide stage (III), consisting of the chalcopyrite–pyrrhotite sub-stage (III-1) and the arsenopyrite–sphalerite sub-stage (III-2). Two types of garnet (Grt-I and Grt-II) have been identified in stage I and both belong to the grossular–andradite solid solution. Grt-II (Gro52-73And25-45Spe+Pyr+Alm2-3) contains slightly more Fe than Grt-I (Gro64-76And20-28Spe+Pyr+Alm2-10). Grt-I is enriched in heavy rare-earth elements (HREEs) and depleted in light rare-earth elements (LREEs), whereas Grt-II is enriched in LREEs and depleted in HREEs. Grt-I has higher U contents and lower Th/U ratios than those of Grt II, indicating a lower oxygen fugacity for the earlier skarn alteration. In contrast to Grt-I, Grt-II shows a more significant negative Eu anomaly along with lower LREEs/HREEs. Therefore, Grt-I and Grt-II likely formed under mildly acidic and near-neutral conditions, respectively. The W (350–3015 ppm) and Fe (235–3740 ppm) contents and Zr/Hf ratios (18.7–49.4) of cassiterite from Gongjuelong are similar to those of cassiterite from the granite-related Sn deposits, as well as the Xiasai hydrothermal vein-type Pb–Zn–Ag deposit in the northern Yidun Terrane. The Ti/Ge ratio (0.06–1.13) and P contents (13.9–173 ppm) of quartz are also similar to those from the Xiasai Pb–Zn–Ag deposit, both of which resemble those of skarn-type deposits and Sn-associated quartz. Furthermore, the Ti/Zr ratio (average 33.2) of cassiterite at Gongjuelong are much higher than that of cassiterite at Xiasai (average 3.7), indicating that the Pb–Zn–Ag veins could represent the distal product of the “parent” granite. On the basis of combined evidence from geology, geochemistry, and published geochronology data, we propose that the proximal skarn-type Sn deposits and distal hydrothermal vein-type Pb–Zn–Ag±Sn deposits in the northern Yidun Terrane constitute an integrated ore system, which is genetically related to the late Cretaceous highly fractionated granites. This proposed hypothesis highlights the potential prospecting of Sn mineralization beneath the hydrothermal Pb–Zn–Ag veins, as well as the hydrothermal Pb–Zn–Ag veins controlled by faults/fractures within the strata around the Sn deposits and highly fractionated granites. Full article
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7 pages, 1104 KiB  
Technical Note
New Technology of Zinc Oxide Concentrate Flotation + Mechanical Stirring Defoaming Zinc Leaching
by Chen Yang, Qingxin Xu, Ruidong Xu, Xiaocai He and Shengnan Lin
Minerals 2025, 15(3), 313; https://doi.org/10.3390/min15030313 - 18 Mar 2025
Viewed by 197
Abstract
During the acidic leaching of flotation zinc oxide concentrates, CO2 released from carbonate decomposition generates viscous foams that disrupt process stability. This study introduces an innovative synergistic defoaming process combining air flotation and mechanical methods. Fine air bubbles destabilize the foam, while [...] Read more.
During the acidic leaching of flotation zinc oxide concentrates, CO2 released from carbonate decomposition generates viscous foams that disrupt process stability. This study introduces an innovative synergistic defoaming process combining air flotation and mechanical methods. Fine air bubbles destabilize the foam, while mechanical defoaming enhances the removal of residual bubbles. The results indicate that the defoaming process combining air flotation with mechanical stirring effectively reduces foam generation during the acid leaching of zinc oxide concentrates, enhances leaching efficiency, and improves process stability. This method provides an effective solution for foam control and offers a new approach for the treatment of zinc oxide concentrates. Full article
(This article belongs to the Section Mineral Processing and Extractive Metallurgy)
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28 pages, 11310 KiB  
Article
In Situ Geochemical and Sulfur Isotopic Composition of Pyrites from the Jiepailing Tin–Beryllium Polymetallic Deposit, Southern Hunan Province, China: Implications for Ore-Forming Processes
by Gao-Feng Du, Xiang-Ying Ling, Dan Wang, Wei-Jian Zhou, Liu Yang, You-Yue Lu and Zun-Zun Zhang
Minerals 2025, 15(3), 312; https://doi.org/10.3390/min15030312 - 18 Mar 2025
Viewed by 360
Abstract
The Jiepailing deposit in southern Hunan is a typical large to super-large polymetallic tin deposit enriched in beryllium and other rare metals. To enhance the understanding of the mineralization processes of the Jiepailing deposit, detailed mineralogical, in situ geochemical, and sulfur isotopic analyses [...] Read more.
The Jiepailing deposit in southern Hunan is a typical large to super-large polymetallic tin deposit enriched in beryllium and other rare metals. To enhance the understanding of the mineralization processes of the Jiepailing deposit, detailed mineralogical, in situ geochemical, and sulfur isotopic analyses were conducted on pyrite closely associated with tin–polymetallic mineralization. Five types of pyrite have been identified in the deposit: (1) euhedral to subhedral medium- to coarse-grained pyrite (PyI) in tungsten–tin ore; anhedral fine-grained pyrite (PyII) in tin polymetallic–fluorite ore; anhedral fine-grained or aggregate pyrite (PyIII) in lead–zinc ore; euhedral to subhedral coarse-grained pyrite (PyIV) in beryllium–fluorite mineralization; and subhedral to anhedral fine-grained pyrite (PyV) in carbonate veinlets developed in the wall rock. Backscattered electron imaging indicates consistent structural features across the five types of pyrite. In situ trace element analysis reveals differences in trace element concentrations among the pyrite types. PyI is relatively enriched in Sn, Cu, and Co. In contrast, PyIII is enriched in Pb, Zn, Sn, and Ti, while PyIV and PyV are enriched in Ag and Sb. PyI has a Co/Ni ratio more than 1, while the Co/Ni ratios in the other four types of pyrite are less than 1. LA-MC-ICP-MS in situ sulfur isotope analysis shows δ34S values ranging from 2.5‰ to 5.8‰ (average 4.3‰, PyI), 2.5‰ to 5.8‰ (average 4.3‰, PyII), −7.6‰ to 9.5‰ (average 3.9‰, PyIII), −3.7‰ to 10.6‰ (average 3.6‰, PyIV), and 6.8‰ to 14.1‰ (average 9.2‰, PyV). Based on previous studies, regional geological background, deposit characteristics, and the in situ trace element and sulfur isotope compositions of pyrite, it is inferred that the various ore bodies in the Jiepailing deposit are products of Late Cretaceous magmatic–hydrothermal activity. The early ore-forming fluid originated from magmatic sources and during the migration into the wall rock and shallow formations, mixed with fluids primarily derived from atmospheric precipitation. Temperature, pressure, and composition changed of the ore-forming fluid which carried a large amount of substances, leading to tungsten–tin, tin polymetallic–fluorite, lead–zinc, and beryllium–fluorite mineralization, followed by carbonation during the late-stage mineralization. Full article
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19 pages, 23644 KiB  
Article
Joint Modeling of Floor Elevations and Thickness of a Bauxite Unit Considering Trend, Histogram and Variogram Uncertainty
by Oktay Erten and Clayton V. Deutsch
Minerals 2025, 15(3), 311; https://doi.org/10.3390/min15030311 - 17 Mar 2025
Viewed by 308
Abstract
Laterite-type bauxite deposits typically exhibit a highly irregular boundary between the bauxite and underlying ferricrete units. This irregularity cannot be accurately modeled using data collected from sparsely spaced drillholes (e.g., 76.2×76.2 m or 250×250 ft). Geological models that assume [...] Read more.
Laterite-type bauxite deposits typically exhibit a highly irregular boundary between the bauxite and underlying ferricrete units. This irregularity cannot be accurately modeled using data collected from sparsely spaced drillholes (e.g., 76.2×76.2 m or 250×250 ft). Geological models that assume a sharp and nearly horizontal bauxite/ferricrete contact can result in significant errors when calculating the in situ bauxite resource (in volume) and in misclassifying ore and waste during mining operations. Two primary sources of uncertainty must be addressed when modeling lateritic bauxite deposits: (1) grade uncertainty associated with variations in Al2O3 and SiO2% concentrations, and (2) geometric uncertainty related to lateral variations in the bauxite/ferricrete contact. Among these, geometric uncertainty is more critical, as accurately estimating bauxite ore tonnage depends on the precise modeling of the lateral variation in the boundary between the bauxite and underlying ferricrete units. This study evaluates the uncertainty of the bauxite resource within a selected mine area in northern Queensland, Australia, particularly in cases where experimental data are sparse and limited. To address this, the position variable (bauxite floor elevations) and the thickness of the bauxite unit are jointly simulated under two scenarios. In the first scenario, the histograms, variogram model parameters, and the estimated trend of the variables of interest are assumed to be known with certainty; that is, parameter uncertainty is not considered in the modeling process. In the second scenario, the histograms, variogram model parameters, and the estimated trend are considered uncertain, and parameter uncertainty is explicitly incorporated into the modeling process using the multivariate spatial bootstrap procedure. The methodology is applied to both scenarios, showing that incorporating parameter uncertainty in geostatistical modeling results in greater dispersion of the uncertainty associated with the in situ bauxite resource. The results show that the 95% confidence intervals for the in situ bauxite ore volume, derived from bauxite thickness realizations, vary depending on whether parameter uncertainty is considered. When parameter uncertainty is incorporated, the interval is (390,123 m3 and 393,223 m3), whereas without parameter uncertainty, it is (382,332 m3 and 384,373 m3). This comparison highlights that incorporating parameter uncertainty provides a more realistic assessment of resource risk in the modeling process. Full article
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21 pages, 29782 KiB  
Article
Metallogenic Process of Forming the Large Xiangcaowa Karstic Bauxite Deposit from the Southern Margin of the North China Craton
by Wenxia Wang, Xuefei Sun, Lei Liu, Lihua Zhao, Rongrong Liang, Tongyi Zhang and Xuefei Liu
Minerals 2025, 15(3), 310; https://doi.org/10.3390/min15030310 - 17 Mar 2025
Viewed by 320
Abstract
North China Craton (NCC) formed the world’s largest karstic bauxite belt in the Late Carboniferous, with significant variations in metallogenic sources and conditions, which affect the overall understanding of karstic bauxite genesis. The Xiangcaowa bauxite deposit in the southern NCC is a large [...] Read more.
North China Craton (NCC) formed the world’s largest karstic bauxite belt in the Late Carboniferous, with significant variations in metallogenic sources and conditions, which affect the overall understanding of karstic bauxite genesis. The Xiangcaowa bauxite deposit in the southern NCC is a large deposit of uncertain provenance and genesis. This study employed geological, mineralogical, and chronology analysis to investigate the sources and genesis of Xiangcaowa bauxite, further contributing to a full understanding of the origin of bauxite throughout the NCC. Xiangcaowa ore-bearing rock series is composed of bauxite and claystone layers. The composition of bauxite ore encompasses diaspore, kaolinite, anatase, pyrite, zircon, and rutile. Widely developed mineral assemblages, such as diaspore–anatase–pyrite, indicate that bauxite is mainly formed in reducing and alkaline karstic depressions. Detrital zircons, aged ~450, ~520, ~950, and ~1100 Ma, predominantly originate from igneous rocks in the North Qinling Orogenic Belt (NQOB), and the ~1650 and ~2400 Ma zircon age populations are primarily from the southern margin of the NCC. Detrital rutiles, which are concentrated in 800–510 Ma, are primarily from the metamorphic rocks of the South Qinling Orogenic Belt (SQOB); rutiles aged ~1500–910 Ma are primarily from metamorphic rocks in the NQOB. These results confirm that the principal sources of the bauxite are the igneous and metamorphic rocks within the NQOB, along with the metamorphic rocks of the SQOB, while the basement rocks of the NCC contribute only minorly to its formation. A large karstic bauxite deposit was formed by the transport of large amounts of weathered material into extensive karstic depressions where reducing and alkaline conditions favoured diaspore deposition. Full article
(This article belongs to the Section Mineral Deposits)
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14 pages, 3067 KiB  
Article
Towards an Extended Concept of Tolerance Factors for Postspinel Phases
by Oliver Tschauner
Minerals 2025, 15(3), 309; https://doi.org/10.3390/min15030309 - 17 Mar 2025
Viewed by 222
Abstract
It is shown that molar and ionic volumes are linearly related for compounds AB2O4 in the spinel-, calcium-ferrate, -titanate, and -manganate structure types at ambient and at high pressure. These relations quantify the concept of ‘chemical pressure’ by relating it [...] Read more.
It is shown that molar and ionic volumes are linearly related for compounds AB2O4 in the spinel-, calcium-ferrate, -titanate, and -manganate structure types at ambient and at high pressure. These relations quantify the concept of ‘chemical pressure’ by relating it to thermodynamic pressure. Full article
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13 pages, 5666 KiB  
Article
Research on the Dry Deep Flip-Flow Screening of Ilmenite and Its Pre-Throwing Tail Processing Technology
by Wei Shi, Weinan Wang, Pengfei Mao, Xu Hou, Songxue Zhang and Chenlong Duan
Minerals 2025, 15(3), 308; https://doi.org/10.3390/min15030308 - 16 Mar 2025
Viewed by 148
Abstract
Screening is a key step in the mineral process of ilmenite. As the grading particle size decreases, the phenomenon of clogged holes on the screening-plate intensifies, the screening environment deteriorates, and the screening effect deteriorates, seriously restricting subsequent sorting operations. This study proposes [...] Read more.
Screening is a key step in the mineral process of ilmenite. As the grading particle size decreases, the phenomenon of clogged holes on the screening-plate intensifies, the screening environment deteriorates, and the screening effect deteriorates, seriously restricting subsequent sorting operations. This study proposes a 1 mm dry flip-flow screening method for ilmenite to achieve efficient deep classification of fine-grained materials. Firstly, a laser displacement testing system is used to study the dynamic characteristics of the flip-flow screen; based on the characteristics of different feed particle sizes, further research is conducted on the 1 mm dry flip-flow screening effect of ilmenite under different ratios of obstructive particles and difficult-to-screen particles. The 1 mm screening effect can reach 85.41%. Finally, the pre-throwing tailings process based on 1 mm multi-stage screening is put forward. This pre-throwing tail process has the characteristic of not using water and is suitable for sorting in arid, water deficient, and high-altitude frozen soil areas. It has important promotion and application value. Full article
(This article belongs to the Special Issue Advances in the Theory and Technology of Physical Separation)
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12 pages, 2785 KiB  
Article
Crystal Chemistry, High-Pressure Behavior, Water Content, and Thermal Stability of Natural Spodumene
by Yuhui Jiang, Jiayi Yu, Yuanze Ouyang, Li Zhang, Xiaoguang Li, Zhuoran Zhang and Yunxuan Li
Minerals 2025, 15(3), 307; https://doi.org/10.3390/min15030307 - 16 Mar 2025
Viewed by 363
Abstract
Spodumene (LiAlSi2O6) is a member of pyroxene-group minerals. It has the highest theoretical lithium abundance among all of the Li-bearing minerals. In the present work, in situ high-pressure Raman spectroscopic investigation of natural spodumene have been conducted up to [...] Read more.
Spodumene (LiAlSi2O6) is a member of pyroxene-group minerals. It has the highest theoretical lithium abundance among all of the Li-bearing minerals. In the present work, in situ high-pressure Raman spectroscopic investigation of natural spodumene have been conducted up to 19.04 GPa. Unheated spodumene and spodumene recovered after heat treatments (up to 1000 °C) have also been analyzed by X-ray diffraction and infrared spectroscopy. The results indicate that spodumene, after the displacive C2/cP21/c transformation triggered at ~3.2 GPa, remains stable at pressures up to 19 GPa at ambient temperature without undergoing decomposition, amorphization, or a second phase transition. The major OH bands of the spodumene samples are observed within the wavenumber range of 2580–3220 cm−1, implying a strong hydrogen bond interaction. The water content of the spodumene is estimated to be 19–97 ppm wt. H2O based on the integrated absorption area of the OH bands. The FTIR analysis of the spodumene samples recovered after heat treatments implies that spodumene can retain a significant amount of water (up to ~100 ppm H2O by weight) under high-temperature conditions up to 1000 °C. This suggests that spodumene in subducted slabs is unlikely to undergo dehydration at temperatures below 1000 °C, and is therefore not expected to trigger partial melting. Thus, spodumene may serve as a key carrier for Li, transporting it into the deep mantle without releasing Li into melts during subduction. Full article
(This article belongs to the Special Issue High-Pressure and High-Temperature Mineral Physics)
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13 pages, 6469 KiB  
Article
An Investigation of the Impact of Altering the Contact Sequence Among Gas, Liquid, and Solid Phases on Mineral Floatability
by Dengfeng Han, Shuaixing Shi, Shuhan Chen, Wentao Hu and Chuanyao Sun
Minerals 2025, 15(3), 306; https://doi.org/10.3390/min15030306 - 16 Mar 2025
Viewed by 268
Abstract
The fundamental processes in flotation involve the collision, adhesion, and detachment between bubbles and mineral particles. The hydration film, which is commonly found on the surface of both particles and bubbles, hinders the effective interaction between the gas, liquid, and solid phases. To [...] Read more.
The fundamental processes in flotation involve the collision, adhesion, and detachment between bubbles and mineral particles. The hydration film, which is commonly found on the surface of both particles and bubbles, hinders the effective interaction between the gas, liquid, and solid phases. To address this challenge, this paper introduces a Reverse Sequence Collision Flotation (RSCF) model, which changes the conventional sequence of gas–liquid–solid interactions. Theoretical analysis reveals that, compared to the traditional flotation process, the proposed model enhances the collision and adhesion between bubbles and mineral particles. Building upon this, preliminary studies were carried out to develop both a single-bubble static reverse sequence collision testing system and a multi-bubble dynamic reverse sequence collision testing system. These systems were used to conduct both qualitative and quantitative analyses of the collision and adhesion effects, thereby confirming the feasibility and separability of the RSCF model. Furthermore, the study demonstrated that mechanical disturbance can be used to adjust the bubble loading, thus creating a new enrichment strategy based on the RSCF model. In conclusion, the RSCF model presents a novel approach to improving flotation efficiency. Future research should focus on optimizing this model and exploring its application potential across different mineral systems. Full article
(This article belongs to the Special Issue Particle–Bubble Interactions in the Flotation Process)
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21 pages, 6869 KiB  
Article
Sensitivity Analysis of Simulation Parameters to Evaluate the Coarse-Grain DEM for Liner Wear Prediction
by Xiaoteng Zheng, Yujie Shen, Huanwei Yu, Zheming Zhu and Xiyong Du
Minerals 2025, 15(3), 305; https://doi.org/10.3390/min15030305 - 16 Mar 2025
Viewed by 255
Abstract
The coarse-grain discrete element method (DEM) has emerged as an effective approach for investigating large-scale granular flow systems. This study performs a sensitivity analysis to evaluate whether parameter calibration in DEM simulations can adequately predict liner wear patterns in tumbling mills. The findings [...] Read more.
The coarse-grain discrete element method (DEM) has emerged as an effective approach for investigating large-scale granular flow systems. This study performs a sensitivity analysis to evaluate whether parameter calibration in DEM simulations can adequately predict liner wear patterns in tumbling mills. The findings emphasize the critical importance of selecting appropriate sliding friction coefficients fs (optimized as 0.10 in this investigation) for accurate quantitative prediction of total liner wear rates. In contrast, the restitution coefficient e demonstrated negligible influence within the current modeling framework. However, several discrepancies were noted: the model systematically underestimated peak transient wear rates while overestimating wear rates in inter-lifter regions of the mill liners. These discrepancies primarily stem from variations in sliding intensity induced by the coarse-grain methodology. Full article
(This article belongs to the Section Mineral Processing and Extractive Metallurgy)
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16 pages, 5089 KiB  
Article
Green Process for the Preparation of MnCO3 and Recovery of By-Product Mg-Containing (NH4)2SO4 Solution
by Xuran Ding, Xunlong Cheng, Zhanfang Cao, Hong Zhong, Hongyan Cai, Gangxiang Xiao, Xin Ma and Shuai Wang
Minerals 2025, 15(3), 304; https://doi.org/10.3390/min15030304 - 15 Mar 2025
Viewed by 702
Abstract
The conventional manganese carbonate preparation process faces challenges such as low resource utilization efficiency and difficulties in treating by-product Mg-containing ammonium sulfate solution. In this study, a two-stage leaching process was developed to efficiently extract Mn and Mg from the ore. NH4 [...] Read more.
The conventional manganese carbonate preparation process faces challenges such as low resource utilization efficiency and difficulties in treating by-product Mg-containing ammonium sulfate solution. In this study, a two-stage leaching process was developed to efficiently extract Mn and Mg from the ore. NH4HCO3 was used as a precipitant to convert Mn2+ in the leachate to MnCO3, achieving a Mn precipitation efficiency of 99.89%, and the resulting product contained 44.45% Mn, meeting the first-class product indicators of HG/T 4203-2011 (Chinese standard on manganese carbonate for industrial use). To further enhance resource utilization, a combined stripping–adsorption process was designed to treat the Mg-containing ammonium sulfate solution generated during the carbonization process. Subsequently, the economically valuable gypsum and magnesium oxide products were prepared. Additionally, 88.20% of the NH3 in the solution was stripped and recycled to prepare NH4HCO3 and then used during carbonization. Finally, a purified solution free of ammonia nitrogen was obtained using 001×7 resin to dynamically adsorb the filtrates obtained during the stripping process, and the maximum adsorption capacity of resin for ammonia nitrogen was 51.14 mg/g. This process provides a novel approach to achieving clean production in the manganese carbonate production industry. Full article
(This article belongs to the Section Mineral Processing and Extractive Metallurgy)
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22 pages, 38178 KiB  
Article
Study on the Key Factors Controlling Oil Accumulation in a Multi-Source System: A Case Study of the Chang 9 Reservoir in the Triassic Yanchang Formation, Dingbian Area, Ordos Basin, China
by Zishu Yong, Jingong Zhang, Jihong Li, Baohong Shi, Zhenze Wang and Feifei Wang
Minerals 2025, 15(3), 303; https://doi.org/10.3390/min15030303 - 15 Mar 2025
Viewed by 398
Abstract
Reservoir evaluation in multi-source systems is challenging because studies generally follow single-source principles. This limitation has substantially hindered the understanding of reservoir and hydrocarbon accumulation processes in source–reservoir systems. This study examines the Dingbian area of the Ordos Basin, China, and investigates the [...] Read more.
Reservoir evaluation in multi-source systems is challenging because studies generally follow single-source principles. This limitation has substantially hindered the understanding of reservoir and hydrocarbon accumulation processes in source–reservoir systems. This study examines the Dingbian area of the Ordos Basin, China, and investigates the key factors controlling hydrocarbon accumulation in the Chang 9 reservoir of the Triassic Yanchang Formation within a multi-source system. The study area spans approximately 0.9 × 104 km2. First, by comparing the biological markers in Chang 9 crude oil with those of potential source rocks, the oil source of the Chang 9 reservoir was identified. The study area was subsequently divided into three provenance zones—northeast, northwest, and central mixed source areas—based on heavy mineral content and the orientation of sedimentary sand bodies. Additionally, well logging data, oil production data, petrographic thin sections, scanning electron microscopy (SEM), and mercury injection porosimetry were used to investigate the reservoir characteristics, oil reservoir features, and crude oil properties across different source areas. The results indicate that the oil source of the Chang 9 reservoir in the Dingbian area is the Upper Chang 7 source rock. The northwest source area exhibits superior reservoir properties compared to the other two zones. In the northwest source area, lithology-structure oil reservoirs are predominant, whereas the central mixed source area is characterized by structural-lithology oil reservoirs, and the northeast source area predominantly features lithology-controlled reservoirs. From the northwest to the central mixed source areas, and finally to the northeast source area, crude oil density and viscosity increase gradually, while the degree of oil–water separation decreases correspondingly. Based on these findings, the study concludes that the distribution of structures, lithology, and source rocks significantly influences the Chang 9 reservoirs in the Dingbian area. The controlling factors of oil reservoirs differ across the various source zones. In multi-source systems, evaluating oil reservoirs based on source zones provides more precise insights into the characteristics of reservoirs in each area. This approach provides more accurate guidance for exploration and development in multi-source regions, as well as for subsequent “reserve enhancement and production increase” strategies. Full article
(This article belongs to the Section Mineral Exploration Methods and Applications)
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18 pages, 32050 KiB  
Article
Mineralogical and Micro-Computer Tomographic (μCT) Texture Investigations of Egyptian Blue Spheres (Aguntum, East Tyrol; Retznei and Wagna, Flavia Solva, South Styria)
by Gerald Degenhart, Julius Heinemann, Peter Tropper, Alexandra Rodler-Rørbo, Bianca Zerobin, Martin Auer and Gert Goldenberg
Minerals 2025, 15(3), 302; https://doi.org/10.3390/min15030302 - 15 Mar 2025
Viewed by 793
Abstract
Egyptian Blue was the first synthetic pigment by humankind. It contains of cuprorivaite, which is a calcium-copper-silicate (CaCuSi4O10). This study reports the results of a mineralogical and computer tomographic study of Egyptian Blue finds from Aguntum in East Tyrol [...] Read more.
Egyptian Blue was the first synthetic pigment by humankind. It contains of cuprorivaite, which is a calcium-copper-silicate (CaCuSi4O10). This study reports the results of a mineralogical and computer tomographic study of Egyptian Blue finds from Aguntum in East Tyrol along with Retznei and Wagna (formerly Flavia Solva) from southern Styria in Austria. The present work aims to extend our understanding of the processes involved in the production of the artificial pigment Egyptian Blue. The samples were investigated with respect to their elemental composition and spatial distribution of the calcium-copper-silicate cuprorivaite CaCuSi4O10 and then compared with data from previous studies. Thin sections of an Egyptian Blue sphere from Aguntum were examined using optical microscopy (OP), micro-X-ray fluorescence analysis (μ-XRF) and scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM-EDX). The pigment’s initial mixture as well as the manufacturing process seem to be the decisive factor for the quality of the final product. A relationship between the presence of trace iron (Fe) and titanium (Ti) with the quartz and copper source of the initial mixture is discussed. SEM-EDX analysis revealed that cuprite (Cu2O) was used as a copper source. In addition, micro-computed tomography (µCT) of the Egyptian Blue finds (Aguntum, Retznei, Wagna-Flavia Solva) was performed. Hence, revealing several concise differences between the samples. Texture and volumetric results show a distinctive difference in cuprorivaite content and particle size. To better analyse the spatial distribution, µCT-3D images of the individual mineral phases identified within each sample were obtained. The clear differences in the results may not only enable a differentiation of the production process but also show another potential of non-destructive µCT for assessment of archaeological findings. Full article
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21 pages, 13716 KiB  
Article
A 3D Geological Modeling Method Using the Transformer Model: A Solution for Sparse Borehole Data
by Zhenquan Hang, Tao Xue, Jianping Chen, Yujin Shi, Zehang Yin, Zijia Cui and Guanyun Zhou
Minerals 2025, 15(3), 301; https://doi.org/10.3390/min15030301 - 15 Mar 2025
Viewed by 711
Abstract
Three-dimensional (3D) geological models are essential for geological analysis and mineral resource estimation. Although conventional on-site survey methods, such as boreholes, provide local engineering geological information for 3D geological modeling, accurately predicting strata in areas with sparse borehole data remains a challenge. This [...] Read more.
Three-dimensional (3D) geological models are essential for geological analysis and mineral resource estimation. Although conventional on-site survey methods, such as boreholes, provide local engineering geological information for 3D geological modeling, accurately predicting strata in areas with sparse borehole data remains a challenge. This study proposes a 3D geological modeling method using the Transformer model under the conditions of sparse borehole data. First, a K-dimensional tree was used to identify boreholes adjacent to the target point, and a borehole context sequence was constructed using stratigraphic information from neighboring boreholes. Subsequently, the relationship between the target point and its adjacent borehole sequence was calculated using the multi-head attention mechanism of the Transformer model. Finally, trained Transformer encoders were used to predict the stratigraphic category of the target point, and the normalized information entropy was used to quantify uncertainty during the modeling process. Experimental results showed that the accuracy of the method was 0.86, outperforming the accuracy and uncertainty of a recurrent neural network. The root mean square error is smaller than the inverse distance weight and Kriging. Compared to other methods, the proposed method can more accurately describe the geometric shape and distribution of geological bodies and reveal the sedimentary laws of the study area. Full article
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14 pages, 1801 KiB  
Article
Material Flow Detection Method for Grinding Conveyor Belt Based on Improved GOOSE Algorithm
by Hao Peng, Lifang He, Danyang Li and Haopo Tang
Minerals 2025, 15(3), 300; https://doi.org/10.3390/min15030300 - 14 Mar 2025
Viewed by 313
Abstract
The detection of material flow rate on grinding conveyor belts is of great significance in grinding operations. In order to overcome the shortcomings of existing material flow rate detection methods and improve the accuracy and adaptability of material flow rate detection, this paper [...] Read more.
The detection of material flow rate on grinding conveyor belts is of great significance in grinding operations. In order to overcome the shortcomings of existing material flow rate detection methods and improve the accuracy and adaptability of material flow rate detection, this paper applies digital image processing technology and intelligent optimization algorithms to it. A material flow rate detection method for grinding conveyor belts based on the improved GOOSE algorithm is proposed, which detects the cross-sectional area of mineral materials using the improved GOOSE algorithm, and finally calculates the material flow rate of grinding conveyor belts based on mathematical models. Comparative experiments show that the method proposed in this paper has the advantages of high detection accuracy and strong adaptability. Full article
(This article belongs to the Section Mineral Processing and Extractive Metallurgy)
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21 pages, 12517 KiB  
Article
The Joint Bayesian Inversion of CSAMT and DC Data for the Jinba Gold Mine in Xinjiang Using Physical Property Priors
by Qianwei Dai, Dan Duan, Yun Wu, Zhexian Xiong and Luyao Guo
Minerals 2025, 15(3), 299; https://doi.org/10.3390/min15030299 - 14 Mar 2025
Viewed by 298
Abstract
We perform Bayesian joint inversion on controlled-source audio-frequency magnetotelluric (CSAMT) and direct current (DC) resistivity data using geostatistical modeling to incorporate prior constraints on physical properties. This study focuses on the Jinba gold deposit in Xinjiang, China, demonstrating the effectiveness of integrating CSAMT [...] Read more.
We perform Bayesian joint inversion on controlled-source audio-frequency magnetotelluric (CSAMT) and direct current (DC) resistivity data using geostatistical modeling to incorporate prior constraints on physical properties. This study focuses on the Jinba gold deposit in Xinjiang, China, demonstrating the effectiveness of integrating CSAMT and DC resistivity data in enhanced subsurface imaging. By leveraging prior knowledge and employing Markov chain Monte Carlo (MCMC) sampling, we quantify the uncertainty in inversion results and compare the improvements offered by joint inversion over single-method approaches. Full article
(This article belongs to the Section Mineral Exploration Methods and Applications)
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2 pages, 354 KiB  
Correction
Correction: Wang et al. Timing and Nature of Gemstone Tsavorite from Kenya: Constraints from In Situ U-Pb LA-ICP-MS Dating. Minerals 2025, 15, 46
by Shiqi Wang, Nai Wang, Siyi Zhao and Sen Wang
Minerals 2025, 15(3), 298; https://doi.org/10.3390/min15030298 - 14 Mar 2025
Viewed by 224
Abstract
There was an error in Figure 5 of the original publication [...] Full article
(This article belongs to the Section Mineral Geochemistry and Geochronology)
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