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Volume 14
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Minerals, Volume 14, Issue 9 (September 2024) – 35 articles

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18 pages, 4565 KiB  
Article
Curing Agent for High-Concentration Unclassified Tailings Stockpiling: A Case Study of Tailings from a Gold Mine
by Weixiang Wang, Kun Li, Lijie Guo, Sha Wang, Yifan Chu and Yao Lu
Minerals 2024, 14(9), 884; https://doi.org/10.3390/min14090884 - 29 Aug 2024
Abstract
The disposal of tailings has always been a focal point in the mining industry. Semi-dry tailings stockpiling, specifically high-concentration tailings stockpiling, has emerged as a potential solution. To enhance the stability of tailings stockpiling and minimize its costs, the incorporation of a low-cost [...] Read more.
The disposal of tailings has always been a focal point in the mining industry. Semi-dry tailings stockpiling, specifically high-concentration tailings stockpiling, has emerged as a potential solution. To enhance the stability of tailings stockpiling and minimize its costs, the incorporation of a low-cost curing agent into high-concentration tailings is essential. Therefore, this study focuses on the development of a curing agent for high-concentration unclassified tailings stockpiling. The composition of a low-cost curing agent system is determined based on theoretical analysis, and the curing reaction mechanisms of each composition are researched. Subsequently, an orthogonal experiment is designed, and the strength of the modified unclassified tailings solidified samples at different curing ages is measured. Furthermore, the rheological properties of the modified unclassified tailings slurries are tested, and the feasibility of industrial transportation of the unclassified tailings slurries modified with the optimized curing agent is analyzed. Lastly, the microscopic morphologies of each material and the modified unclassified tailings solidified samples are characterized, their chemical compositions are tested, and the action mechanism of the curing agent in the curing system is further investigated. The results show that the optimal proportions of each material in the curing agent are as follows: slag, 58%; quicklime, 15%; cement, 8%; gypsum, 9%; and bentonite, 10%. The dominance of industrial waste slag exceeding 50% reflects the low-cost nature of the curing agent. Under this condition, the modified unclassified tailings slurry with a mass concentration of 75% exhibited a yield stress of 43.62 Pa and a viscosity coefficient of 0.67 Pa·s, which is suitable for pipeline transportation. These findings lay a foundation for subsequent decisions regarding stockpiling processes and equipment selection. Full article
(This article belongs to the Special Issue Advances in Mine Backfilling Technology and Materials)
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12 pages, 2099 KiB  
Article
Vladimirivanovite Revised: General Crystal Chemistry and Isomorphous Substitutions of Extra-Framework Species
by Nadezhda B. Bolotina, Nikita V. Chukanov, Anatoly N. Sapozhnikov, Natalia V. Zubkova, Igor V. Pekov, Dmitry A. Varlamov, Marina F. Vigasina, Maria O. Bulakh, Vasiliy O. Yapaskurt and Dmitry A. Ksenofontov
Minerals 2024, 14(9), 883; https://doi.org/10.3390/min14090883 - 29 Aug 2024
Abstract
New data on the crystal structure, chemical composition, and nature of extra-framework components of the orthorhombic sodalite-group mineral vladimirivanovite were obtained using chemical and single-crystal X-ray diffraction data as well as infrared and Raman spectroscopy. The crystal structure of vladimirivanovite is based on [...] Read more.
New data on the crystal structure, chemical composition, and nature of extra-framework components of the orthorhombic sodalite-group mineral vladimirivanovite were obtained using chemical and single-crystal X-ray diffraction data as well as infrared and Raman spectroscopy. The crystal structure of vladimirivanovite is based on the sodalite-type aluminosilicate framework with ordered Al and Si atoms. Sodalite-like cages are mainly occupied by Na+ and Ca2+ cations and (SO4)2− anions. It was shown that vladimirivanovite is characterized by significant variations in the content of extra-framework polysulfide groups (S3•−, S4), as well as other neutral molecules (H2O and CO2), the presence of which in the structure is the main cause of structural modulations and the orientation disordering of sulfate anions. Three samples with different S3•−:S4 ratios were studied. All of them are orthorhombic (space group Pnaa) with the unit-cell parameters a ≈ 9.1, b ≈ 12.9, and c ≈ 38.6 Å; Z = 6. The general crystal-chemical formula of vladimirivanovite is (Na+6.0–6.4Ca2+1.5–1.7)(Al6Si6O24)(SO42−,S3•−,S4)1.7–1.9(CO2)0–0.1·nH2O (n = 1–3), where the S4 molecule occurs in different conformation states. Full article
(This article belongs to the Special Issue Isomorphism, Chemical Variability, and Solid Solutions of Minerals and Related Compounds, 2nd Edition)
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20 pages, 11742 KiB  
Article
Distribution Characteristics and Hydrocarbon Significance of Deep-Water Fine-Grained Sedimentary Rocks in the Steep-Slope Zone of a Graben Lake Basin: A Case Study of Es3l sub-Member in the Jiyang Depression, Bohai Bay Basin, China
by Qi Zhong, Wangpeng Li, Hui Huang, Jianhui Jiang, Jianguo Zhang, Pinxie Li, Yali Liu, Jiabin Wu, Fenghua Wang, Bintian Tan and Ruo Jia
Minerals 2024, 14(9), 882; https://doi.org/10.3390/min14090882 - 29 Aug 2024
Abstract
The high exploration and development production capacity of the Jiyang Depression, Bohai Bay Basin, China in the early stage confirms the huge exploration and development potential of shale oil in the study area. Due to the complexity of the depositional mechanism in the [...] Read more.
The high exploration and development production capacity of the Jiyang Depression, Bohai Bay Basin, China in the early stage confirms the huge exploration and development potential of shale oil in the study area. Due to the complexity of the depositional mechanism in the study area, the distribution law of fine-grained sedimentary rocks is not well understood, which restricts further exploration breakthroughs. This paper comprehensively observes rock cores and thin sections, combines mineral components, Rock-Eval pyrolysis, rock-cutting logging and logging data to classify lithofacies, and clarifies the distribution law of various lithofacies. The research results show that, according to lithological characteristics, various lithofacies origins are classified into three categories: terrigenous, mixed, and endogenous sources, and six lithofacies types are distinguished: terrigenous low-organic-matter massive siltstone (LF1), terrigenous low-organic-matter massive mudstone (LF2), mixed-source medium-organic-matter massive mudstone (LF3), mixed-source medium-to-high-organic matter laminated-massive mudstone (LF4), mixed-source medium-to-high-organic-matter laminated mudstone (LF5), and endogenous-sourced medium-to-high-organic matter laminated limestone (LF6). The distribution of lithofacies in plane is symmetrical in the east–west direction and is characterized by a banded distribution; the distribution in profile shows a stable depositional process and a continuous depositional sequence. The various lithofacies depositional models have been summarized; the terrigenous input from the northern steep-slope zone has influenced the hydrodynamic conditions of the lake basin, significantly affecting the lithofacies depositional variations from the steep-slope zone to the deep-sag area. The geological evaluation of each lithofacies has been conducted; LF1 + LF4 + LF5 are classified as Class I—target reservoirs for shale oil development, while LF3 + LF6 are considered Class II—favorable reservoirs. The result of the study provide a reference for the classification of fine-grained sedimentary-rock facies and distribution characteristics, and the evaluation of shale-oil-reservoir sweet spots in graben lake basins. Full article
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13 pages, 4701 KiB  
Article
Effect of Gas Dispersion Properties and Bias in Scheelite Column Flotation
by HyunSoo Kim and Chul-Hyun Park
Minerals 2024, 14(9), 881; https://doi.org/10.3390/min14090881 - 29 Aug 2024
Abstract
In this study, column flotation was used to recover a high-grade concentrate from low-grade WO3 ore. Gas dispersion properties, such as superficial gas velocity, gas holdup, bubble size, bubble surface area flux, carrying rate, and bias, were investigated in two phases (gas–liquid) [...] Read more.
In this study, column flotation was used to recover a high-grade concentrate from low-grade WO3 ore. Gas dispersion properties, such as superficial gas velocity, gas holdup, bubble size, bubble surface area flux, carrying rate, and bias, were investigated in two phases (gas–liquid) and three phases (gas–liquid–solid) in the column, and their effects on the grade and recovery of WO3. It was confirmed that the gas velocity significantly affected these factors, with the gas holdup, bubble size, bubble surface area flux, and carrying rate tending to increase as the gas velocity increased. The bias increased with an increase in the wash water velocity. The results showed that the grade and recovery of WO3 could be controlled within a specific range of operating conditions of bias (0.27–0.48 cm/s) and carrying rate (10.53–18.83 g/min/cm2). Correlation plots of grade/recovery versus bias and carrying rate revealed that the optimal separation achievable for a given WO3 concentrate in a flotation column was a 72.16% grade with a 78.3% recovery, satisfying the metallurgical requirement of more than 50% for WO3. Full article
(This article belongs to the Special Issue Recent Advances in Separation Techniques for Critical Minerals/Metals, Circular Economy, and Sustainability)
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18 pages, 4239 KiB  
Article
The Role of Mineral and Organic Composition on the Phosphorus Content of Prehistoric Pottery (Middle Neolithic to Late Bronze Age) from NW Spain
by María Guadalupe Castro González, María Pilar Prieto Martínez and Antonio Martínez Cortizas
Minerals 2024, 14(9), 880; https://doi.org/10.3390/min14090880 - 29 Aug 2024
Viewed by 73
Abstract
Phosphorus is a key element for identifying past human activity. Recently, phosphorus analyses have been extended to archaeological objects, aiming at distinguishing how depositional contexts contribute to its enrichment. In archaeological pottery, phosphorus might depend on several manufacturing and postdepositional processes (i.e., addition [...] Read more.
Phosphorus is a key element for identifying past human activity. Recently, phosphorus analyses have been extended to archaeological objects, aiming at distinguishing how depositional contexts contribute to its enrichment. In archaeological pottery, phosphorus might depend on several manufacturing and postdepositional processes (i.e., addition of organic temper, pigments, diagenetic incorporation). We analyzed by XRD, XRF, and mid-infrared (FTIR-ATR) spectroscopy 178 pots from eight NW Spain archaeological sites. These sites encompass different chronologies, contexts, and local geology. The phosphorus content was highly variable (224–27,722 mg kg−1) overall but also between archeological sites (1644 ± 487 to 13,635 ± 6623 mg kg−1) and within archaeological sites (4–36, max/min ratio). No phosphate minerals were identified by XRD nor FTIR-ATR, but correlations between phosphorus content and MIR absorbances showed maxima at 1515 and 980 cm−1, suggesting the presence of two sources: one organic (i.e., phosphorylated aromatic compounds) and another inorganic (i.e., albite and K-feldspar). Phosphorylated aromatics were most likely formed during pottery firing and were preserved due to their high resistance to temperature and oxidation. Meanwhile, albite and K-feldspar are among the P-bearing minerals with higher P concentrations. Our results suggest that P content is related to intentional and non-intentional actions taken in the pottery production process. Full article
(This article belongs to the Special Issue The Significance of Applied Mineralogy in Archaeometry)
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14 pages, 4953 KiB  
Article
Effect of Fine Particle Content on Solution Flow and Mass Transfer of Ion-Adsorption-Type Rare Earth Ores
by Lingbo Zhou, Hongdong Yu, Shijie Kang, Guidong Sun, Yang Deng, Xiaojun Wang, Hanlin Zhao and Jingtao Xu
Minerals 2024, 14(9), 879; https://doi.org/10.3390/min14090879 - 28 Aug 2024
Viewed by 201
Abstract
Fine particle content significantly affects the in situ leaching of ion-adsorption-type rare earth ores. This study investigated the effect of fine particle content on solution flow and mass transfer in leaching. The results showed that with the increase in fine particle content, the [...] Read more.
Fine particle content significantly affects the in situ leaching of ion-adsorption-type rare earth ores. This study investigated the effect of fine particle content on solution flow and mass transfer in leaching. The results showed that with the increase in fine particle content, the peak concentration and peak time of rare earth increased. When the fine particle content exceeded 20%, all ion-exchangeable-phase rare earth ions could be replaced with a low dosage of the leaching solution. The leachate flow rate exhibited multi-stage variation, influenced by solution permeation, ion exchange, and fluctuations in accumulated liquid height. A mass transfer analysis showed that a higher fine particle content corresponded to a smaller plate height and a larger plate number of theoretical plates. As fine particle content increased, the final rising height of capillary water decreased, with rising rates varying across different stages for the samples. Moreover, an increase in fine particle content from 5% to 20% resulted in a 94% decrease in the samples’ permeability coefficients. A mechanism analysis showed that when the fine particle content was higher, the fine particles were embedded in the gaps between coarse particles, and the ore particles in the sample were arranged continuously, resulting in a lower permeability coefficient. Then, the leaching solution could penetrate uniformly, which was beneficial for reducing leaching blind spots and improving leaching efficiency. However, excessive fine particle content might have detrimental effects. Based on these results and considering actual mining conditions, the optimal fine particle content for rare earth leaching is 20%. Full article
(This article belongs to the Special Issue Green and Efficient Recovery/Extraction of Rare Earth Resources)
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22 pages, 1846 KiB  
Article
Characterization of Lithium-Ion Batteries from Recycling Perspective towards Circular Economy
by Lucas Fonseca Guimarães, Jorge Alberto Soares Tenório, Mentore Vaccari, Denise Crocce Romano Espinosa and Amilton Barbosa Botelho Junior
Minerals 2024, 14(9), 878; https://doi.org/10.3390/min14090878 - 28 Aug 2024
Viewed by 201
Abstract
Recycling processes of lithium-ion batteries used in electric and hybrid vehicles are widely studied today. To perform such recycling routes, it is necessary to know the composition of these batteries and their components. In this work, three pouch and three cylindrical LIBs were [...] Read more.
Recycling processes of lithium-ion batteries used in electric and hybrid vehicles are widely studied today. To perform such recycling routes, it is necessary to know the composition of these batteries and their components. In this work, three pouch and three cylindrical LIBs were discharged, dismantled, and characterized, having their compositions known and quantified. The dismantling was performed using scissors, pliers, and a precision cutter equipment. The organic liquid electrolyte was quantified via mass loss after it evaporated at 60 °C for 24 h. The separators were analyzed using Fourier-transform infrared spectroscopy (FTIR), and the cathode and anode active materials were analyzed using a scanning electronic microscope coupled to an energy-dispersive spectroscope (SEM-EDS), X-ray diffraction (XDR), and energy-dispersive X-ray fluorescence spectrometry (EDXRF). All LIBs were identified by type (NCA, NMC 442, NMC 811, LCO, and two LFP batteries), and a preliminary economic evaluation was conducted to understand their potential economic value (in USD/t). Both results (characterization and preliminary economic evaluation) were considered to discuss the perspective of recycling towards a circular economy for end-of-life LIBs. Full article
(This article belongs to the Section Mineral Processing and Extractive Metallurgy)
12 pages, 2081 KiB  
Article
Abiotic and Biotic Processes Controlling Deposition of Calcite and Hydrotalcite Calcretes on Niue Island, Southwest Pacific
by Paul Aharon and Neil E. Whitehead
Minerals 2024, 14(9), 877; https://doi.org/10.3390/min14090877 - 28 Aug 2024
Viewed by 166
Abstract
Calcretes are indurated terrestrial carbonates that are widespread in arid and semi-arid settings and serve as important archives of present and past environments. Here, we use geochemical tools to explore the nature and origin of calcretes documented from tropical Niue Island in the [...] Read more.
Calcretes are indurated terrestrial carbonates that are widespread in arid and semi-arid settings and serve as important archives of present and past environments. Here, we use geochemical tools to explore the nature and origin of calcretes documented from tropical Niue Island in the Southwest Pacific. The study recognizes two types of calcretes that differ in their mineral assemblage, microfabrics, elemental chemistry, and carbon and oxygen isotopes. The calcretes common in the paleo-lagoon soils consist of 90% low-Mg calcite and ~10% highly weathered Mg-Al silicates. These pedogenic calcretes formed in the soil profiles within the vadose zone bear the following distinctions: (i) Fe/Al ratio of 0.75, identical to the ratio in soils (Fe/Al = 0.76 ± 0.5), substantiating the link between the calcretes and soils; (ii) presence of rhizoliths, root voids, micritic nodules, and clasts, which are consistent with a pedogenic calcrete fabric; and (iii) 13C and 18O depletions of −10.6‰ and −5.3‰, respectively, which are compatible with carbon sources from microbial and root respiration, as well as formation in oxygen isotope equilibrium with vadose waters. Unlike the pedogenic calcrete, a rare calcrete from the coastal terrace contains an exceptionally rare hydrotalcite [Mg6Al2(CO3)(OH)16(H2O)4] mineral (65%) coated by microbial films. We contend that the hydrotalcite-rich calcrete was deposited through interaction of dolomite with seawater, similar to the method of producing hydrotalcite in the laboratory. 13C and 18O enrichments of 0.8 to 1.7‰ and −1.0 to −1.6‰, respectively, are in agreement with (i) mixed carbon sources consisting of microbial CO2 degassing, seawater HCO3, and dolomite dissolution, and (ii) oxygen isotope equilibration with seawater-derived fluid. Full article
(This article belongs to the Section Biomineralization and Biominerals)
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15 pages, 4111 KiB  
Article
Utilizing Magnesium Carbonate Induced by CO2 to Modify the Performance of Plastic Clay
by Hadi Mohamadzadeh Romiani, Hamed Abdeh Keykha, Saeed Chegini, Afshin Asadi and Satoru Kawasaki
Minerals 2024, 14(9), 876; https://doi.org/10.3390/min14090876 - 28 Aug 2024
Viewed by 166
Abstract
Highly plastic clays pose significant challenges in engineering projects. Various techniques have been employed to enhance their properties, though many face difficulties related to implementation and environmental impact. This study examines the effect of CO2-induced magnesium carbonate on improving the geotechnical [...] Read more.
Highly plastic clays pose significant challenges in engineering projects. Various techniques have been employed to enhance their properties, though many face difficulties related to implementation and environmental impact. This study examines the effect of CO2-induced magnesium carbonate on improving the geotechnical behavior of plastic clay. CO2-induced magnesium carbonate was produced via mineral carbonation and used to improve the behavior of highly plastic natural clay. CO2 gas was injected into a sodium hydroxide solution to produce carbonate ions (CO32−). Magnesium carbonate was precipitated on a laboratory scale by adding magnesium sulfate solution to the carbonate ion solution. Clayey soil samples were obtained from test pits in the Meyghan Plain near Arak, Iran. The clay samples were treated with different percentages of the produced magnesium carbonate. Various parameters of the treated and untreated samples, including index properties, unconfined compressive strength, consolidation behavior, and swelling potential, were studied. It was found that the liquid limit and plasticity index of the treated clay decreased as the magnesium carbonate content increased. The soil classification changed from high plastic clay (CH) to low plastic silt (ML) with the addition of 15% magnesium carbonate to the highly plastic clay. The unconfined compressive strength of the treated clay increased. Additionally, the consolidation behavior and swelling index of the treated clay improved as the magnesium carbonate content increased. This study confirms that CO2-induced magnesium carbonate is a promising material for improving the behavior of highly plastic clays, offering a sustainable approach to environmental management. Full article
(This article belongs to the Special Issue Clay Minerals and CO2 Capture, Utilization and Storage)
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19 pages, 5430 KiB  
Article
Investigating the Influence of Medium Size and Ratio on Grinding Characteristics
by Xin Fang, Caibin Wu, Ningning Liao, Jiuxiang Zhong, Xuqian Duan, Shenglin Zhu, Aijun Liu and Ke Xiao
Minerals 2024, 14(9), 875; https://doi.org/10.3390/min14090875 - 27 Aug 2024
Viewed by 236
Abstract
This study explores the effect of steel ball size and proportion on mineral grinding characteristics using Discrete Element Method (DEM) simulations. Based on batch grinding kinetics, this paper analyzes the contact behavior during grinding, discussing particle breakage conditions and critical breakage energy. The [...] Read more.
This study explores the effect of steel ball size and proportion on mineral grinding characteristics using Discrete Element Method (DEM) simulations. Based on batch grinding kinetics, this paper analyzes the contact behavior during grinding, discussing particle breakage conditions and critical breakage energy. The results indicate that while increasing the size of the steel balls leads to higher collision energy, the collision probability decreases significantly; the opposite is true for smaller steel balls. Simulation results with different ball size combinations show that increasing the proportion of smaller balls does not significantly change the collision energy but greatly increases the collision probability, providing a basis for optimizing ball size distribution to improve grinding performance. Furthermore, appropriately increasing the proportion of smaller balls can reduce fluctuations in grinding energy consumption, thereby enhancing collision energy and collision probability while reducing energy costs. Liner wear results demonstrate that larger ball sizes increase liner wear, but different ball size combinations can effectively distribute the forces on the liner, reducing wear. Full article
(This article belongs to the Special Issue Experimental and Numerical Studies of Mineral Comminution: 3rd Edition)
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18 pages, 8969 KiB  
Article
Petrogenesis and Geodynamic Mechanisms of Porphyry Copper Deposits in a Collisional Setting: A Case from an Oligocene Porphyry Cu (Au) Deposit in Western Yangtze Craton, SW China
by Mimi Yang, Xingyuan Li, Guoxiang Chi, Hao Song, Zhengqi Xu and Fufeng Zhao
Minerals 2024, 14(9), 874; https://doi.org/10.3390/min14090874 - 27 Aug 2024
Viewed by 238
Abstract
The Xifanping deposit is a distinct Cenozoic porphyry Cu (Au) deposit located in the Sanjing porphyry metallogenic belt 100–150 km east of the JinshajFiang fault in the western Yangtze craton. We present new zircon U–Pb–Lu–Hf isotopic studies and geochemical data of the ore-bearing [...] Read more.
The Xifanping deposit is a distinct Cenozoic porphyry Cu (Au) deposit located in the Sanjing porphyry metallogenic belt 100–150 km east of the JinshajFiang fault in the western Yangtze craton. We present new zircon U–Pb–Lu–Hf isotopic studies and geochemical data of the ore-bearing quartz monzonite porphyry from the Xifanping deposit to determine their petrogenesis and geodynamic mechanisms. LA–ICP–MS zircon U–Pb dating yielded precise emplacement ages of 31.87 ± 0.41 Ma (MSWD = 0.86) and 32.24 ± 0.61 Ma (MSWD = 1.8) for quartz monzonite porphyry intrusions, and 254.9 ± 5.1 Ma (MSWD = 1.7) for inherited zircons of the monzonite porphyry. The ore-bearing monzonite porphyry is characterized by high-K calc–alkaline to shoshonite and peraluminous series, relatively enriched in light over heavy REEs, with no distinct Eu anomalies, as well as enrichment in LILEs and depletion of HFSEs, with adakitic affinities. The zircon Lu–Hf isotope data ranged from εHf(t) values of −2.94 to +3.68 (average −0.47) with crustal model (TDM2) ages ranging from 0.88 to 1.30 Ga, whereas the inherited zircons displayed positive εHf(t) values ranging from +1.83 to +7.98 (average +5.82), with crustal model (TDM2) ages ranging from 0.77 to 1.17 Ga. Results suggest that the Xifanping porphyry Cu (Au) deposit is related to two periods of magmatic activities. Early magmas were generated from the Paleo-Tethys oceanic subduction during the Late Permian. The subsequent porphyry magma was likely formed by the remelting of previously subduction-modified arc lithosphere, triggered by the continental collision between the Indian and Asian plates in the Cenozoic. The deep magmas and late hydrothermal fluids took advantage of the early magma transport channels along tectonically weak zones during the transition from an extrusive to an extensional–tensional tectonic environment. Early dikes from remelted and assimilated crust contributed to the two age ranges observed in the porphyry intrusions from the Xifanping deposit. The juvenile lower crust materials of the early magmatic arc were potential sources of the Cenozoic porphyry magmas, which has significant implications for mineral exploration and the geological understanding of porphyry Cu deposits in this region. Full article
(This article belongs to the Section Mineral Deposits)
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20 pages, 57677 KiB  
Article
Application of Target Detection Based on Deep Learning in Intelligent Mineral Identification
by Luhao He, Yongzhang Zhou and Can Zhang
Minerals 2024, 14(9), 873; https://doi.org/10.3390/min14090873 - 27 Aug 2024
Viewed by 208
Abstract
In contemporary society, rich in mineral resources, efficiently and accurately identifying and classifying minerals has become a prominent issue. Recent advancements in artificial intelligence, particularly breakthroughs in deep learning, have offered new solutions for intelligent mineral recognition. This paper introduces a deep-learning-based object [...] Read more.
In contemporary society, rich in mineral resources, efficiently and accurately identifying and classifying minerals has become a prominent issue. Recent advancements in artificial intelligence, particularly breakthroughs in deep learning, have offered new solutions for intelligent mineral recognition. This paper introduces a deep-learning-based object detection model for intelligent mineral identification, specifically employing the YOLOv8 algorithm. The model was developed with a focus on seven common minerals: biotite, quartz, chalcocite, silicon malachite, malachite, white mica, and pyrite. During the training phase, the model learned to accurately recognize and classify these minerals by analyzing and annotating a large dataset of mineral images. After 258 rounds of training, a stable model was obtained with high performance on key indicators such as Precision, Recall, mAP50, and mAP50–95, with values stable at 0.91766, 0.89827, 0.94300, and 0.91696, respectively. In the testing phase, using samples provided by the Geological and Mineral Museum at the School of Earth Sciences and Engineering, Sun Yat-sen University, the model successfully identified all test samples, with 83% of them having a confidence level exceeding 87%. Despite some potential misclassifications, the results of this study contribute valuable insights and practical experience to the development of intelligent mineral recognition technologies. Full article
(This article belongs to the Special Issue Application of Big Data Mining, Machine Learning and Artificial Intelligence in Geoscience, 2nd Edition)
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18 pages, 14342 KiB  
Article
Characteristics and Control Factors of a High-Quality Deeply Buried Calcareous Sandstone Reservoir, the Fourth Member of the Upper Xujiahe Formation in the Western Sichuan Basin, China
by Dong Wu, Yu Yu, Liangbiao Lin, Hongde Chen and Sibing Liu
Minerals 2024, 14(9), 872; https://doi.org/10.3390/min14090872 - 27 Aug 2024
Viewed by 213
Abstract
A special type of sandstone in which carbonate rock fragments (CRFs) dominate the composition developed in the Upper Triassic Xujiahe Formation’s fourth member (Xu4) in the western Sichuan Basin, known as calcareous sandstone. Calcareous sandstones are widely distributed in the western Sichuan and [...] Read more.
A special type of sandstone in which carbonate rock fragments (CRFs) dominate the composition developed in the Upper Triassic Xujiahe Formation’s fourth member (Xu4) in the western Sichuan Basin, known as calcareous sandstone. Calcareous sandstones are widely distributed in the western Sichuan and is the main production target of tight sandstone gas in the Sichuan Basin. In this study, thin sections, porosity–permeability testing, scanning electron microscopy, and X-ray diffraction are applied to examine the characteristics and control factors for high-quality reservoirs in the calcareous sandstones, with a view to providing guidance for natural gas exploration and development in calcareous sandstones. The results show that the calcareous sandstone belongs to litharenite, with an average framework grain composition of 30% quartz, 1% feldspar, and 69% rock fragments, while the Xu4 sandstone has a high quartz content (average content of 71%). Primary intergranular pores are the main storage space, and the reservoir quality is quite poor. Under the influence of different parent rock properties of sandstones, there are obvious differences in the composition of framework grains between the calcareous sandstone and the ordinary Xu4 sandstone, which in turn affects the reservoir storage space, diagenesis, and reservoir quality. High-energy depositional conditions, low content of late cements, and the development of fractures are the main controlling factors for the formation of high-quality reservoirs in Xu 4 calcareous sandstones. Full article
(This article belongs to the Section Mineral Deposits)
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19 pages, 6614 KiB  
Article
The Genesis of Ultramafic Rock Mass on the Northern Slope of Lüliang Mountain in North Qaidam, China
by Haiming Guo, Yanguang Li, Bo Chen, Huishan Zhang, Xiaoyong Yang, Li He, Yongjiu Ma, Yunping Li, Jincheng Luo and Haichao Zhao
Minerals 2024, 14(9), 871; https://doi.org/10.3390/min14090871 - 27 Aug 2024
Viewed by 168
Abstract
The ultramafic rock located on the northern slope of Lüliang Mountain in the northwestern region of North Qaidam Orogen is altered to serpentinite. The occurrence of disseminated chromite within the serpentinite holds significant implications for understanding the petrogenesis of the protolith. This work [...] Read more.
The ultramafic rock located on the northern slope of Lüliang Mountain in the northwestern region of North Qaidam Orogen is altered to serpentinite. The occurrence of disseminated chromite within the serpentinite holds significant implications for understanding the petrogenesis of the protolith. This work provides strong evidence of a distinct zonal texture in the chromite found in the ultramafic rock, using petrographic microstructure and electron probe composition analysis. The core of the chromite is characterized by high contents of Cr#, with enrichment in Fe3+# (Fe3+/(Cr + Al + Fe3+)) and depletion in Al2O3 and TiO2. The Cr2O3 content ranges from 51.64% to 53.72%, while the Cr# values range from 0.80 to 0.84. The FeO content varies from 24.9% to 27.8%, while the Fe2O3 content ranges from 5.19% to 8.74%. The Al2O3 content ranges from 6.70% to 9.20%, and the TiO2 content is below the detection limit (<0.1%). Furthermore, the rocks exhibit Mg# values ranging from 0.13 to 0.25 and Fe3+# values ranging from 0.07 to 0.12. The mineral chemistry of the chromite core in the ultramafic rock suggests it to be from an ophiolite. This ophiolite originated from the fore-arc deficit asthenosphere in a supra-subduction zone. The estimated average crystallization temperature and pressure of the chromite are 1306.02 °C and 3.41 GPa, respectively. These values suggest that the chromite formed at a depth of approximately 110 km, which is comparable to that of the asthenosphere. The chromite grains are surrounded by thick rims composed of Cr-rich magnetite characterized by enrichment in Fe3+# contents and depletions in Cr2O3, Al2O3, TiO2, and Cr#. The FeO content ranges from 28.25% to 31.15%, while the Fe2O3 content ranges from 44.94% to 68.92%. The Cr2O3 content ranges from 0.18% to 23.59%, and the Al2O3 and TiO2 contents are below the detection limit (<0.1%). Moreover, the rim of the Cr-rich magnetite exhibits Cr# values ranging from 0.90 to 1.00, Mg# values ranging from 0.01 to 0.06, and Fe3+# values ranging from 0.64 to 1.00, indicating late-stage alteration processes. The LA-ICP-MS zircon U-Pb dating of the ultramafic rock yielded an age of 480.6 ± 2.4 Ma (MSWD = 0.46, n = 18), representing the crystallization age of the ultramafic rock. This evidence suggests that the host rock of chromite is an ultramafic cumulate, which is part of the ophiolite suite. It originated from the fore-arc deficit asthenosphere in a supra-subduction zone during the northward subduction of the North Qaidam Ocean in the Ordovician period. Furthermore, clear evidence of Fe-hydrothermal alteration during the post-uplift-denudation stage is observed. Full article
(This article belongs to the Special Issue Metallogenesis of the Central Asian Orogenic Belt)
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17 pages, 18056 KiB  
Article
New Insights into the Depressive Mechanism of Sodium Silicate on Bastnaesite, Parisite, and Fluorite: Experimental and DFT Study
by Jieliang Wang, Wenda Lu, Zhao Cao, Xu Wu, Peng Wang, Xiaoping Wang and Wenli Liu
Minerals 2024, 14(9), 870; https://doi.org/10.3390/min14090870 - 27 Aug 2024
Viewed by 237
Abstract
The surface properties of bastnaesite and parisite are similar to their associated gangue mineral, fluorite, which makes the flotation separation of these two rare earth minerals from fluorite one of the industry’s most significant challenges. This study systematically investigates the inhibitory effects and [...] Read more.
The surface properties of bastnaesite and parisite are similar to their associated gangue mineral, fluorite, which makes the flotation separation of these two rare earth minerals from fluorite one of the industry’s most significant challenges. This study systematically investigates the inhibitory effects and mechanisms of sodium silicate (SS) on bastnaesite, parisite, and fluorite in an octyl hydroxamic acid (OHA) collector system through flotation experiments, various modern analytical methods, and DFT simulations. The flotation test results indicate that the inhibition effects of SS on the three minerals are in the order: fluorite > parisite > bastnaesite. Detection and analysis results indicate that SS forms hydrophilic complexes with Ca atoms on the surfaces of fluorite and parisite, enhancing surface hydrophilicity and inhibiting OHA adsorption, but its impact on bastnaesite is relatively minor. DFT simulation results show that OHA forms covalent bonds with metal ions on mineral surfaces, favoring five-membered hydroxamic-(O-O)-Ce/Ca complexes, and reacts more strongly with Ce atoms than Ca atoms. SS primarily forms covalent bonds with metal atoms on mineral surfaces via the SiO(OH)3− component, and OHA and SS compete for adsorption on the mineral surfaces. OHA has a stronger affinity for bastnaesite, whereas SS shows the highest affinity for fluorite, followed by parisite, and the weakest affinity for bastnaesite. Full article
(This article belongs to the Special Issue Selected Papers from the 7th International Conference of Young Scholars in Mineral Processing)
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20 pages, 6048 KiB  
Article
Mineralogical Characterization and Geochemical Signatures of Supergene Kaolinitic Clay Deposits: Insight of Ropp Complex Kaolins, Northcentral Nigeria
by Adamu Yunusa, Hanlie Hong, Atif Salim, Tarig Amam, Chen Liu, Yanxiao Xu, Xiaochao Zuo and Zhaohui Li
Minerals 2024, 14(9), 869; https://doi.org/10.3390/min14090869 - 27 Aug 2024
Viewed by 394
Abstract
This study presents the chemical and mineralogical composition of clay deposits and associated rock types within the Ropp Complex in order to assess the influence of parent lithology on the kaolinization, genesis, and utility of the deposit. Representative kaolin samples from E horizons [...] Read more.
This study presents the chemical and mineralogical composition of clay deposits and associated rock types within the Ropp Complex in order to assess the influence of parent lithology on the kaolinization, genesis, and utility of the deposit. Representative kaolin samples from E horizons of the weathering profiles and their bedrocks were collected from six sites in the Ropp Complex. Clay mineralogy was determined via the XRD technique, while a geochemical analysis was conducted using XRF, SEM coupled with EDS, and ICP-MS. The results showed that all kaolins dominantly contain kaolinite with a content of 77%–98% except for the AS1 kaolin with only minor kaolinite (20%) but mainly illite (65%). The notably lower crystallinity of kaolinite (HI value of 0.53–1.1) as well as its markedly small grain size is consistent with the formation of kaolinite from intensive chemical weathering of igneous rocks. The AS1 kaolin was probably formed from hydrothermal alteration in the burial stage due to the heating of groundwater by the late volcanism. Mobile trace elements (Sr, Ba, and Eu) exhibited a depletion trend, while immobile elements (Hf, Ta, Th) showed enrichment. The relatively more zirconium in kaolins implies the formation of low-temperature kaolinization. The notably high kaolinite content, accompanied by reasonable levels of Fe2O3 and TiO2, signifies a medium-grade quality. Furthermore, chondrite-normalized rare earth element (REE) patterns exhibit congruent trends in rocks and kaolin samples, indicating a relative enrichment in light rare earth elements (LREEs) alongside a discernible negative Eu anomaly. The abundant kaolinite and silicon–aluminum composition make the kaolins suitable for refractories, pharmaceutics, cosmetics, and supplementary cementitious material (SCM). Full article
(This article belongs to the Collection Clays and Other Industrial Mineral Materials)
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21 pages, 7190 KiB  
Article
Experimental and Simulation Studies on the Mn Oxidation State Evolution of a Li2O-MnOx-CaO-SiO2 Slag Analogue
by Sven Hampel, Iyad Alabd Alhafez, Alena Schnickmann, Sophie Wunderlich, Haojie Li, Michael Fischlschweiger, Thomas Schirmer, Nina Merkert and Ursula E. A. Fittschen
Minerals 2024, 14(9), 868; https://doi.org/10.3390/min14090868 - 26 Aug 2024
Viewed by 216
Abstract
This manuscript presents the results from the synthesis and characterization of a slag analogue with a nominal composition of 17 wt% LiMnO2 and 83 wt% Ca2SiO4 encountering fairly high cooling rates in order to study the evolution of Mn-species. [...] Read more.
This manuscript presents the results from the synthesis and characterization of a slag analogue with a nominal composition of 17 wt% LiMnO2 and 83 wt% Ca2SiO4 encountering fairly high cooling rates in order to study the evolution of Mn-species. The Mn species was also simulated from 1223 K to 1773 K using a thermodynamic model, assuming a homogeneous melt. The micro-composition including the Mn species of the solidified slag was determined experimentally, and was used as basis for molecular dynamics (MD) simulation. The MD simulation provides information on structure and viscosity at high temperatures, which are otherwise difficult to access. These parameters significantly influence oxidation state of redox-active elements and the solidified product. The micro-composition analyzed by electron probe micro analysis (EPMA) and synchrotron-based micro-X-ray fluorescence (micro-XRF) showed that Mn-rich and Ca-Si-rich phases are separated. While the Mn-O phases did not contain noticeable Ca, the Ca2SiO4 phase had incorporated 0.6 wt% of Mn. The slag solidified into round-shaped and droplet-shaped grains of a Li-Mn-oxide, some Mn3O4 and Ca2SiO4. The powder X-ray diffraction (PXRD) confirmed the formation of larnite; the identity of the Li-Mn-oxide, however, remained inconclusive. The Mn oxidation state (OS) was identified using synchrotron-based micro-X-ray absorption near edge spectroscopy (micro-XANES). The Mn-O grains matched well with Li-Mn-oxides and a Mn OS: +3, e.g., LiMn3+O2. Small areas matching hausmannite (Mn2+Mn23+O4) were also identified. The OS of Mn in the silicate phase could not be identified. For comparison, a slowly cooled slag analogue with similar composition, but higher Si content, was also subjected to micro-XANES. The slowly cooled slag formed long Mn-rich needles in a matrix of large calcium silicate crystals. The Mn-rich crystals matched well with the XANES spectrum of a Mn3+ Li-oxide like LiMn3+O2. At the rim of the needles, the Mn-spectra matched well the hausmannite (Mn2+Mn23+O4) reference. In the silicate phases, Mn had an OS: +2, unambiguously. The melt structure at different temperatures of two compositions, i.e., LiMn3+O2 and Ca2SiO4, was simulated using molecular dynamics (MD). They serve as model compositions, assuming a heterogeneous melt. The results show significant different degrees of polymerization and viscosity. Information from MD simulations can support the identification of potentially different oxygen permeability and with that prediction of oxidation states. The bulk composition was identified by inductively coupled plasma optical emission spectrometry (ICP-OES), bulk structure by PXRD and bulk species by lab-XANES. The synchrotron micro analysis including micro-XRD were performed at the microfocus beamline I18 at the Diamond Light Source. Pure reference compounds were prepared and characterized with the same multi-modal approach. Full article
(This article belongs to the Special Issue Artificial Engineered Minerals: Synthesis, Characterization, Metallurgical and Mechanical Processing)
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20 pages, 5864 KiB  
Article
Novel Indigenous Strains and Communities with Copper Bioleaching Potential from the Amolanas Mine, Chile
by Julián C. Casas-Vargas, Cristóbal Martínez-Bussenius, Álvaro Videla and Mario Vera
Minerals 2024, 14(9), 867; https://doi.org/10.3390/min14090867 - 26 Aug 2024
Viewed by 452
Abstract
Bioleaching, a process catalyzed by acidophilic microorganisms, offers a sustainable approach to metal extraction from sulfide minerals. Chalcopyrite, the world’s most abundant copper sulfide, presents challenges due to surface passivation limiting its bioleaching efficiency. Also, indigenous species and microbial communities may present high [...] Read more.
Bioleaching, a process catalyzed by acidophilic microorganisms, offers a sustainable approach to metal extraction from sulfide minerals. Chalcopyrite, the world’s most abundant copper sulfide, presents challenges due to surface passivation limiting its bioleaching efficiency. Also, indigenous species and microbial communities may present high copper extraction rates and offer new possibilities for application in bioleaching processes. This study examines the bioleaching potential of microbial isolates and communities obtained from Amolanas Mine in Chile. Samples were collected, cultivated, and identified by Sanger sequencing. The bioleaching potential and biofilm formation of isolates and enrichments were evaluated on pyrite and chalcopyrite. The results show the isolation of nine Leptospirillum and two Acidithiobacillus strains. The bioleaching experiments demonstrated good copper bioleaching potentials of the Leptospirillum I2CS27 strain and EICA consortium (composed mainly of Leptospirillum ferriphilum, Acidiphilium sp., and Sulfobacillus thermosulfidooxidans), with 11% and 25% copper recovery rates, respectively. Microbial attachment to the surface mineral was not mandatory for increasing the bioleaching rates. Our findings underscore the importance of indigenous microbial communities in enhancing copper bioleaching efficiency. Full article
(This article belongs to the Special Issue Sustainable Extraction of Copper, Nickel and Zinc and Their By-Products from Ores, Recycled Materials and Wastes through Hydrometallurgical Processes)
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14 pages, 5646 KiB  
Article
Synchrotron Micro-X-ray Diffraction in Transmission Geometry: A New Approach to Study Polychrome Stratigraphies in Cultural Heritage
by Giulia Morabito, Nicoletta Marinoni, Giorgio Bais, Marco Cantaluppi, Alessandra Botteon, Chiara Colombo, G. Diego Gatta, Maurizio Polentarutti, Marco Realini and Elena Possenti
Minerals 2024, 14(9), 866; https://doi.org/10.3390/min14090866 - 25 Aug 2024
Viewed by 375
Abstract
In cultural heritage, paint stratigraphies are complex systems typically consisting of various paint layers with fine crystalline phases mixed with coarse pigment and filler grains. This complexity poses significant challenges for X-ray diffraction (XRD) analysis. In this work, we employed synchrotron radiation micro-X-ray [...] Read more.
In cultural heritage, paint stratigraphies are complex systems typically consisting of various paint layers with fine crystalline phases mixed with coarse pigment and filler grains. This complexity poses significant challenges for X-ray diffraction (XRD) analysis. In this work, we employed synchrotron radiation micro-X-ray diffraction in transmission geometry (SR-µTXRD) with linear mapping to develop a novel approach for studying the crystalline phases (pigments and fillers) in mock-up paint stratigraphies. A targeted approach was followed for qualitative, quantitative, and microstructural analysis, combining signals from micrometric crystallites and coarse single crystals as well as from randomly oriented and iso-oriented crystalline phases. This allows for identifying, localizing, and quantifying these phases even in low fractions and distinguishes the same phases across different layers with varying grain sizes or spatial orientations. Critical analysis of 2D XRD patterns, coupled with full-profile fitting performed by the Rietveld method, provides insights into material preparation (e.g., grinding), painting technique (e.g., color palette, use of fillers, brushing), and crystallo-chemical modifications over time. This analytical approach, integrating spatially resolved investigation with high-quality phase characterization, enhances the potential of specific XRD methodologies for a 2D investigation of multi-phase materials in cultural heritage, even without dedicated micro-mapping techniques. Full article
(This article belongs to the Special Issue Geomaterials and Cultural Heritage)
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45 pages, 22848 KiB  
Article
Syn-Sedimentary Exhalative or Diagenetic Replacement? Multi-Proxy Evidence for Origin of Metamorphosed Stratiform Barite–Sulfide Deposits near Aberfeldy, Scottish Highlands
by Norman R. Moles, Adrian J. Boyce, Matthew R. Warke and Mark W. Claire
Minerals 2024, 14(9), 865; https://doi.org/10.3390/min14090865 - 25 Aug 2024
Viewed by 469
Abstract
Bedded barite, Fe-Zn-Pb sulfides, carbonates, and cherts within Ediacaran (Dalradian Supergroup) graphitic metasediments near Aberfeldy in Scotland have previously been interpreted as chemical sediments precipitated from hydrothermal fluids episodically exhaled into marine basins filled with organic-rich mud, silt, and sand. Lithological variation and [...] Read more.
Bedded barite, Fe-Zn-Pb sulfides, carbonates, and cherts within Ediacaran (Dalradian Supergroup) graphitic metasediments near Aberfeldy in Scotland have previously been interpreted as chemical sediments precipitated from hydrothermal fluids episodically exhaled into marine basins filled with organic-rich mud, silt, and sand. Lithological variation and compositional diversity in pyrite and sphalerite reflect varied redox environments and proximity to hydrothermal discharges. Thick beds (>2 m) of barite have relatively uniform δ34S of +36 ± 1.5‰, considered to represent contemporaneous seawater sulfate, as negative Δ17O indicates incorporation of atmospheric oxygen during precipitation in the water column. However, certain features suggest that diagenetic processes involving microbial sulfate reduction modified the mineralogy and isotopic composition of the mineralization. Barite bed margins show decimeter-scale variation in δ34S (+32 to +41‰) and δ18O (+8 to +21‰), attributed to fluid-mediated transfer of dissolved barium and sulfate between originally porous barite and adjacent sediments, in which millimetric sulfate crystals grew across sedimentary lamination. Encapsulated micron-sized barium carbonates indicate early diagenetic barite dissolution with incorporation of sulfur into pyrite, elevating pyrite δ34S. Subsequently, sulfidation reactions produced volumetrically minor secondary barite with δ34S of +16 to +22‰. Overall, these processes affected small volumes of the mineralization, which originally formed on the seafloor as a classic SEDEX deposit. Full article
(This article belongs to the Special Issue Stratabound Barite Deposits: Mineralogy, Isotope Geochemistry and Geochronology)
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18 pages, 4345 KiB  
Article
Crystal Chemistry of Synthetic Mg(Si1−xGex)O3 Pyroxenes: A Single-Crystal X-ray Diffraction Study
by Günther J. Redhammer and Gerold Tippelt
Minerals 2024, 14(9), 864; https://doi.org/10.3390/min14090864 - 25 Aug 2024
Viewed by 314
Abstract
Germanate-pyroxenes often are used as model systems to study the stability and phase relationships of analog silicate systems. Based on such analyses, it is assumed that silicates and germanates behave ideally in terms of mixing. A systematic study was performed to monitor in [...] Read more.
Germanate-pyroxenes often are used as model systems to study the stability and phase relationships of analog silicate systems. Based on such analyses, it is assumed that silicates and germanates behave ideally in terms of mixing. A systematic study was performed to monitor in detail the changes introduced by a Si4+ through Ge4+ replacement in the important rock-forming pyroxene enstatite MgSiO3. Well-shaped, idiomorphic singe crystals of a MgSi1−xGexO3 pyroxene solid solution were grown at ambient pressure from a high-temperature flux-assisted synthesis. Structural analysis using single-crystal X-ray diffraction methods revealed orthorhombic symmetry, Pbca, Z = 8, for the complete solid-solution series. Long-term storage over a period of 8 years at ambient conditions or annealing at 525 °C over a period of 10 weeks did not change the symmetry of the proposed thermodynamically stable monoclinic polymorph. Within the solid-solution series, lattice parameters increased almost linearly with increasing Si4+ by Ge4+ substitution. The main changes occurred on the tetrahedral sites, which showed an almost linear increase in individual and average bond lengths but also in distortion parameters. The refined site occupancy of Si4+ and Ge4+ showed a distinct preference of Ge4+ for the TB site. The altered topology and kinking state in the tetrahedral chains also imposed significant changes to the bonding topology and geometry of the neighboring M1 and M2 sites. Full article
(This article belongs to the Section Crystallography and Physical Chemistry of Minerals & Nanominerals)
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32 pages, 7574 KiB  
Article
Source Rock Assessment of the Permian to Jurassic Strata in the Northern Highlands, Northwestern Jordan: Insights from Organic Geochemistry and 1D Basin Modeling
by Dina Hamdy, Sherif Farouk, Abdelrahman Qteishat, Fayez Ahmad, Khaled Al-Kahtany, Thomas Gentzis, Luigi Jovane and Amr S. Zaky
Minerals 2024, 14(9), 863; https://doi.org/10.3390/min14090863 - 25 Aug 2024
Viewed by 341
Abstract
The present study focused on the Permian to Jurassic sequence in the Northern Highlands area, NW Jordan. The Permian to Jurassic sequence in this area is thick and deeply buried, consisting mainly of carbonate intercalated with clastic shale. This study integrated various datasets, [...] Read more.
The present study focused on the Permian to Jurassic sequence in the Northern Highlands area, NW Jordan. The Permian to Jurassic sequence in this area is thick and deeply buried, consisting mainly of carbonate intercalated with clastic shale. This study integrated various datasets, including total organic carbon (TOC, wt%), Rock-Eval pyrolysis, visual kerogen examination, gross composition, lipid biomarkers, vitrinite reflectance (VRo%), and bottom-hole temperature measurements. The main aim was to investigate the source rock characteristics of these strata regarding organic richness, kerogen type, depositional setting, thermal maturity, and hydrocarbon generation timing. The Permian strata are poor to fair source rocks, primarily containing kerogen type (KT) III. They are immature in the AJ-1 well and over-mature in the NH-2 well. The Upper Triassic strata are poor source rocks in the NH-1 well and fair to marginally good source rocks in the NH-2 well, containing highly mature terrestrial KT III. These strata are immature to early mature in the AJ-1 well and at the peak oil window stage in the NH-2 well. The Jurassic strata are poor source rocks, dominated by KT III and KT II-III. They are immature to early mature in the AJ-1 well and have reached the oil window in the NH-2 well. Biomarker-related ratios indicate that the Upper Triassic oils and Jurassic samples are source rocks that received mainly terrestrial organic input accumulated in shallow marine environments under highly reducing conditions. These strata are composed mostly of clay-rich lithologies with evidence of deposition in hypersaline and/or stratified water columns. 1D basin models revealed that the Upper Triassic strata reached the peak oil window from the Early Cretaceous (~80 Ma) to the present day in the NH-1 well and from ~130 Ma (Early Cretaceous) to ~90 Ma (Late Cretaceous) in the NH-2 well, with the late stage of hydrocarbon generation continuing from ~90 Ma to the present time. The present-day transformation ratio equals 77% in the Upper Triassic source rocks, suggesting that these rocks have expelled substantial volumes of hydrocarbons in the NH-2 well. To achieve future successful hydrocarbon discoveries in NW Jordan, accurate seismic studies and further geochemical analyses are recommended to precisely define the migration pathways. Full article
(This article belongs to the Special Issue Environmental Geochemistry and Mineralogy: Application for Hydrocarbon Exploration and Ore Deposits)
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13 pages, 31812 KiB  
Article
Spatial and Temporal Distribution of Igneous Sills in the Central Tarim Basin and Their Geological Implications
by Zewei Yao
Minerals 2024, 14(9), 862; https://doi.org/10.3390/min14090862 - 24 Aug 2024
Viewed by 414
Abstract
Interpretation of the seismic reflection profiles associated with borehole data from the petroleum industry offers a novel way to study sill emplacement in sedimentary basins. This study uses this approach to reveal the intrusive part of the Tarim Large Igneous Province (LIP) within [...] Read more.
Interpretation of the seismic reflection profiles associated with borehole data from the petroleum industry offers a novel way to study sill emplacement in sedimentary basins. This study uses this approach to reveal the intrusive part of the Tarim Large Igneous Province (LIP) within the basin, which has not been systematically reported. A large number of igneous intrusions (sills) are identified in the sedimentary layers of the Central Tarim Basin. The burial depth of the sills is 6–8 km, and they are mainly located within the upper Ordovician strata. According to their seismic facies and drilling data, it is inferred that they are dolerite sills. Based on the uplift of the overlying strata above the intrusions, it is concluded that the sills were mainly formed during the depositional period of the middle Permian Kupukuziman Formation and Kaipailezike Formation (early stage), with a few formed during the depositional period of the upper Permian strata (late stage). It is likely that these two stages of sill intrusion correspond to the main basaltic eruptions within the basin and the mafic dike emplacement in the Bachu area of the Tarim LIP, respectively. The study suggests that that the dolerite sills reported in this study are also an important component of the Permian Tarim LIP. Full article
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23 pages, 2102 KiB  
Review
Unraveling the Potentials of Extremophiles in Bioextraction of Valuable Metals from Industrial Solid Wastes: An Overview
by Adegoke Isiaka Adetunji and Mariana Erasmus
Minerals 2024, 14(9), 861; https://doi.org/10.3390/min14090861 - 24 Aug 2024
Viewed by 377
Abstract
The continuous dumping of industrial solid wastes into the immediate environment is incommodious since these waste materials cause pollution and serious hazards to human health. In addition, these solid wastes are complex and consist of toxic chemical substances, heavy metals, and valuable metals, [...] Read more.
The continuous dumping of industrial solid wastes into the immediate environment is incommodious since these waste materials cause pollution and serious hazards to human health. In addition, these solid wastes are complex and consist of toxic chemical substances, heavy metals, and valuable metals, hence warranting treatment before disposal. Bioleaching is a green and sustainable technology for the solubilization and mobilization of metals from solid matrices. The leaching efficacy is contingent on the types and physiology of the organisms, the elemental content of the solid wastes, and the presence of appropriate bioprocess parameters at optimum conditions. Extremophilic microbes, including thermophiles, acidophiles, alkaliphiles, and halophiles, are recognized as excellent biological agents for the efficient bioextraction of metals from industrial solid wastes due to their aptitude for survival under harsh bioleaching conditions. Therefore, this review provides insights into the employability of extremophilic microorganisms as a biofactory for the recovery of valuable metals from various industrial solid wastes. More so, it discusses the sustainability of the bioleaching technique in terms of its life cycle assessment (LCA) and techno-economic analysis. Full article
(This article belongs to the Special Issue Bioleaching of Metals from Waste/Wastewater)
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34 pages, 16162 KiB  
Review
Updating Geological Information about the Metallogenesis of the Iberian Pyrite Belt
by Reinaldo Sáez, Felipe González, Teodosio Donaire, Manuel Toscano, Lola Yesares, Gabriel Ruiz de Almodóvar and Carmen Moreno
Minerals 2024, 14(9), 860; https://doi.org/10.3390/min14090860 - 24 Aug 2024
Viewed by 341
Abstract
The Iberian Pyrite Belt (IPB) represents one of the largest districts of volcanogenic massive sulfide (VMS) deposits in the world, and is a critical source of base metals (Cu, Pb, and Zn) for Europe. Confirmed resources exceed 1700 Mt of massive sulfides with [...] Read more.
The Iberian Pyrite Belt (IPB) represents one of the largest districts of volcanogenic massive sulfide (VMS) deposits in the world, and is a critical source of base metals (Cu, Pb, and Zn) for Europe. Confirmed resources exceed 1700 Mt of massive sulfides with grades of around 1.2% Cu, 1% Pb, and 3% Zn as well as more than 300 Mt of stockwork-type copper mineralization. Significant resources of Sn, precious metals (Au and Ag), and critical metals (Co, Bi, Sb, In, and Se) have also been evaluated. The genesis of these deposits is related to a complex geological evolution during the late Devonian and Mississippian periods. The geological record of such evolution is represented by three main lithological units: Phyllite–Quartzite Group, the volcano–sedimentary Complex (VSC), and the so-called Culm Group. The sulfide deposits are located in the VSC, associated with felsic volcanic rocks or sedimentary rocks such as black shales. The massive sulfide deposits occur as tabular bodies and replacement masses associated with both volcanic and sedimentary rocks. Their mineralogical composition is relatively simple, dominated by pyrite, chalcopyrite, sphalerite, and galena. Their origin is related to three evolutionary stages at increasing temperatures, and a subsequent stage associated with the Variscan deformation. The present paper summarizes the latest developments in the IPB and revises research areas requiring further investigation. Full article
(This article belongs to the Special Issue Mineral Deposits, Geotectonic Evolution and Mineralogical and Geochemical Characterization of Iberian Pyrite Belt—State of the Art)
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14 pages, 6630 KiB  
Article
Overprinting Mineralization in the Huoluotai Porphyry Cu (Mo) Deposit, NE China: Evidence from K-Feldspar Ar-Ar Geochronology and S-Pb Isotopes
by Yonggang Sun, Zhongjie Yang, Mingliang Wang, Chengcheng Xie, Xusheng Chen and Fanbo Meng
Minerals 2024, 14(9), 859; https://doi.org/10.3390/min14090859 - 24 Aug 2024
Viewed by 230
Abstract
The Great Xing’an Range (GXR) is a significant belt of polymetallic deposits located in the eastern segment of the Central Asian Orogenic Belt. The recently found Huoluotai porphyry Cu (Mo) deposit is situated in the northern GXR region in northeastern (NE) China. The [...] Read more.
The Great Xing’an Range (GXR) is a significant belt of polymetallic deposits located in the eastern segment of the Central Asian Orogenic Belt. The recently found Huoluotai porphyry Cu (Mo) deposit is situated in the northern GXR region in northeastern (NE) China. The deposit has been studied extensively using field geology and geochronological methods, which have identified two distinct mineralization events. These events include an early occurrence of porphyry-type Cu (Mo) mineralization and a later occurrence of vein-type Cu mineralization. Prior geochronology investigations have determined an approximate age of 147 Ma for the early porphyry-type Cu (Mo) mineralization. 40Ar/39Ar dating of K-feldspar of the altered Cu-mineralized quartz diorite porphyry veins for the overprinting vein-type Cu mineralization provides plateau ages of 123.1 ± 1.5 Ma, 122.3 ± 2.8 Ma, and 122.2 ± 0.4 Ma. Sulfide S-Pb isotope compositions of the two mineralization events suggest that both have a magmatic source. The origin of ore-forming metals displays the features of a crust–mantle mixing origin. The regional extensional tectonic setting in NE China during the Early Cretaceous was caused by large-scale lithosphere delamination and upwelling of the asthenospheric mantle. These processes were triggered by the rollback of the Paleo-Pacific Plate. The tectonic event in question resulted in the lithospheric thinning, significant magmatic activity, and mineralization in NE China. Full article
(This article belongs to the Special Issue Genesis and Metallogeny of Non-ferrous and Precious Metal Deposits, 2nd Edition)
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20 pages, 2332 KiB  
Article
Source to Receptor: Assessing Health Risks from Heavy Metal Exposure in Mining Soils
by Gladys Nyoh Belle, Yolandi Schoeman and Paul Johan Oberholster
Minerals 2024, 14(9), 858; https://doi.org/10.3390/min14090858 - 24 Aug 2024
Viewed by 432
Abstract
This research quantifies the health risks associated with exposure to heavy metals in the Matjhabeng Local Municipality, a gold mining region in South Africa, utilising a deterministic source–pathway–receptor approach. This study uniquely integrates both non-carcinogenic and carcinogenic risk assessments across multiple heavy metals, [...] Read more.
This research quantifies the health risks associated with exposure to heavy metals in the Matjhabeng Local Municipality, a gold mining region in South Africa, utilising a deterministic source–pathway–receptor approach. This study uniquely integrates both non-carcinogenic and carcinogenic risk assessments across multiple heavy metals, providing a comprehensive perspective on health impacts in mining-impacted communities. The study measured concentrations of arsenic (As), cadmium (Cd), lead (Pb), cobalt (Co), chromium (Cr), copper (Cu), iron (Fe), nickel (Ni), selenium (Se), and zinc (Zn) in soil samples, with mean values found to be 3.2 mg/kg, 2.5 mg/kg, 45 mg/kg, 17 mg/kg, and 25 mg/kg for As, Cd, Pb, Co, and Cr, respectively. The deterministic assessment revealed minimal non-carcinogenic risks for ingestion across all demographics (HQ < 1), while significant dermal risks were identified for Cd, Pb, Co, and Cr (HQ > 1), particularly for the adult group. The inhalation pathway emerged as a critical exposure route, with HQ values ranging from 5 to 15 and chronic hazard index values significantly exceeding safe limits (CHI > 5). The carcinogenic risk through inhalation notably surpassed the acceptable thresholds set by the United States Environmental Protection Agency (1 × 10−4 to 1 × 10−6), with a calculated lifetime cancer risk far exceeding the limit for As, Cd, Cr, Co, and Ni for both adults and juveniles. These findings underscore the urgent need for targeted risk mitigation strategies in the community to address the significant health risks posed by airborne heavy metal exposure. Full article
(This article belongs to the Special Issue Potentially Toxic Elements: Source, Distribution, Risk Assessment and Remediation)
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18 pages, 7604 KiB  
Article
The Characteristics and Enrichment Process of Dabu Ion-Adsorption Heavy Rare-Earth Element (HREE) Deposits in Jiangxi Province, South China
by Mingjun Xie, Jian Zhou, Xuemiao Du, Xueqiu Wang, Bimin Zhang, Hui Wu, Qinghai Hu, Wei Wang, Mi Tian, Binfeng Chen, Huohua Mo and Lijun Wang
Minerals 2024, 14(9), 857; https://doi.org/10.3390/min14090857 - 24 Aug 2024
Viewed by 332
Abstract
Ion-adsorption rare-earth deposits supply over 90% of the global market’s heavy rare-earth elements (HREEs). The genesis of these deposits, particularly HREE deposits, has garnered significant attention. To elucidate the metallogenic mechanisms of HREE deposits, a comprehensive study of the weathering profile of granite [...] Read more.
Ion-adsorption rare-earth deposits supply over 90% of the global market’s heavy rare-earth elements (HREEs). The genesis of these deposits, particularly HREE deposits, has garnered significant attention. To elucidate the metallogenic mechanisms of HREE deposits, a comprehensive study of the weathering profile of granite was conducted in Jiangxi Province, South China. This study focuses on the following two aspects: the petrogeochemistry of HREE-rich granite and the enrichment and fractionation of rare-earth elements (REEs) during the weathering process. The results suggest that the Dabu granites are a typical peraluminous, high-K, calc-alkaline granite series with high silica content (SiO2: 74.5%–76.4%), relatively low phosphorus content (P2O5: <0.05%), and high HREE content (ΣLREE/ΣHREE: 0.16–0.66). Weathering advances the decomposition of minerals and the release of elements. REEs are mainly fixed in the regolith by scavengers, mainly clays, Fe–Mn oxides, and carbonates, and ΣREE can reach 799 ppm in the B horizon. However, HREEs tend to migrate further and preferentially combine with Fe–Mn oxides and carbonates as compared to LREEs, leading to a significant fractionation of REEs in the regolith (ΣLREE/ΣHREE = 0.2–1.1). Additionally, the differential weathering of REE-bearing minerals and the precipitation of secondary REE-bearing minerals are also vital for REE fractionation. Full article
(This article belongs to the Special Issue Geochemical Exploration for Critical Mineral Resources)
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31 pages, 7774 KiB  
Article
Monchegorsk Mafic–Ultramafic Layered PGE-Bearing Complex (2.5 Ga, Kola Region, Russia): On the Problem of Relationships between Magmatic Phases Based on the Study of Cr-Spinels
by Pavel Pripachkin, Tatiana Rundkvist, Artem Mokrushin and Aiya Bazai
Minerals 2024, 14(9), 856; https://doi.org/10.3390/min14090856 - 24 Aug 2024
Viewed by 287
Abstract
The composition of Cr-spinels from rocks of the Monchegorsk layered complex (2.5 Ga) basically corresponds to the evolutionary trend that is typical for layered mafic–ultramafic intrusions (late magmatic phases contain Cr-spinels enriched in Fe and depleted in Mg, Cr, and Al). Cr-spinels within [...] Read more.
The composition of Cr-spinels from rocks of the Monchegorsk layered complex (2.5 Ga) basically corresponds to the evolutionary trend that is typical for layered mafic–ultramafic intrusions (late magmatic phases contain Cr-spinels enriched in Fe and depleted in Mg, Cr, and Al). Cr-spinels within the Dunite Body of the Sopcha massif are almost identical to those within the Dunite Block rocks and are close to those from harzburgite of the NKT massif. Cr-spinels within the satellite bodies of the Ore Layer 330 are shown to have zonal structure, which confirms their origin from a new portion of melt, which may have been injected with several pulses. The composition of accessory Cr-spinels may indicate that the layered complex of rocks of the South Sopcha massif was formed from the most evolved portion of magmatic melt (linked with the Monchetundra intrusion), and its vein complex may be considered the one formed at the final stages of the magmatic system evolution. The composition of Cr-spinels from the Pentlandite Gorge mafic–ultramafic rocks may indicate that they are fragments of the NKT massif and not of the Monchetundra massif, as it was believed earlier. Full article
(This article belongs to the Section Mineral Deposits)
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14 pages, 14341 KiB  
Article
Sulfidation of Smithsonite via Microwave Roasting under Low-Temperature Conditions
by Jiawei Kang, Shubiao Yin, Mingxiao Li, Xingzhi Zhang, Xujie Wen, Hanping Zhang, Qi Nie and Ting Lei
Minerals 2024, 14(9), 855; https://doi.org/10.3390/min14090855 - 23 Aug 2024
Viewed by 256
Abstract
This study employs microwave roasting to decompose smithsonite mineral (zinc carbonate) into zinc oxide, which then reacts with pyrite to sulfurize its surface, forming zinc sulfide. This process is beneficial for the flotation recovery of zinc oxide minerals. The surface sulfidation behavior of [...] Read more.
This study employs microwave roasting to decompose smithsonite mineral (zinc carbonate) into zinc oxide, which then reacts with pyrite to sulfurize its surface, forming zinc sulfide. This process is beneficial for the flotation recovery of zinc oxide minerals. The surface sulfidation behavior of smithsonite under low-temperature microwave roasting conditions is examined through X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and thermodynamic calculations. XRD and thermodynamic analysis indicate that smithsonite completely decomposes into zinc oxide at 400 °C. Introducing a small amount of pyrite as a sulfidizing reagent leads to the formation of sulfides on the surface of decomposed smithsonite. XPS analysis confirms that the sulfide formed on the surface is zinc sulfide. SEM analysis reveals that sulfides are distributed on the surface of smithsonite, and the average sulfur concentration increases with the pyrite dosage. Microwave-assisted sulfurization of smithsonite (ZnCO3) was found to significantly enhance its floatability compared to conventional sulfurization methods. The optimal mass ratio of ZnCO3 to FeS2 is approximately 1:1.5, with the best temperature being 400 °C. These findings provide a technical solution for the application of microwave roasting in the efficient recovery of smithsonite through flotation. Full article
(This article belongs to the Section Mineral Processing and Extractive Metallurgy)
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