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Minerals, Volume 13, Issue 11 (November 2023) – 108 articles

Cover Story (view full-size image): Multiple overprinting hydrothermal events remain a challenge in metallogenic studies. The Idaho Cobalt Belt presents two distinct metal-rich events that introduced Co and Cu. The pyrite displays various degrees of alteration, with the highest Co content (up to 6 wt.%) in less-altered pyrite and the highest δ65Cu. The most-altered pyrite has lower Co and lower δ65Cu matching the copper isotope values of the chalcopyrite. Cobalt was originally introduced into the siliciclastic host rock in a Mesoproterozoic SEDEX environment. The heavier Cu was then preferentially leached in a second event, resulting in isotopically lighter Cu in the altered pyrite. Remobilization of the SEDEX Co was likely associated with CO2-rich metamorphic fluids during orogenies from the Mesoproterozoic to Late Cretaceous. View this paper
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12 pages, 2884 KiB  
Article
An Improved Understanding of Chalcopyrite Leaching Mechanisms: The Influence of Anisotropic Crystal Planes
Minerals 2023, 13(11), 1461; https://doi.org/10.3390/min13111461 - 20 Nov 2023
Viewed by 767
Abstract
Chalcopyrite (CuFeS2) particles, exposing anisotropic crystal planes during the grinding process, possess comprehensive surface properties that affect their leaching behaviors. In order to investigate the influence of anisotropic crystal planes on the leaching mechanisms, CuFeS2 particles with anisotropic crystal planes [...] Read more.
Chalcopyrite (CuFeS2) particles, exposing anisotropic crystal planes during the grinding process, possess comprehensive surface properties that affect their leaching behaviors. In order to investigate the influence of anisotropic crystal planes on the leaching mechanisms, CuFeS2 particles with anisotropic crystal planes were produced by employing three-head laboratory grinder mill (TM), rod mill (RM), and ball mill (BM) and were then leached in a sulfuric acid solution at pH = 1. Based on the XRD, SEM, XPS, and simulation results, (112), (102), (312), (110), (116), (100), and (001) planes were mainly exposed on the CuFeS2 surface during the crushing and grinding process. In addition, fewer (112), (102), (312), and (110) planes but more (116), (100), and (001) planes were exposed on the CuFeS2 samples in the TM method than in the RM and BM methods. Since the leaching rates were in the order of (001) > (100) > (116) > (110) > (312) > (102) > (112) planes, the Cu extractions followed an order of TM > RM > BM. This study, therefore, provides an excellent theoretical basis for the effect of anisotropic crystal planes on CuFeS2 leaching, further improving the understanding of CuFeS2 leaching mechanisms. Full article
(This article belongs to the Section Mineral Processing and Extractive Metallurgy)
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16 pages, 5230 KiB  
Article
The Use of DEM for Optimising an Industrial Vezin Sampler Operation
Minerals 2023, 13(11), 1460; https://doi.org/10.3390/min13111460 - 20 Nov 2023
Viewed by 711
Abstract
Rotary dividers, also known as “vezin samplers”, are widely used in the mining industry to obtain representative samples of particulate streams, and they are used as primary, secondary, or tertiary samplers. Based on Pierre Gy’s theory of sampling (TOS), the correct extraction of [...] Read more.
Rotary dividers, also known as “vezin samplers”, are widely used in the mining industry to obtain representative samples of particulate streams, and they are used as primary, secondary, or tertiary samplers. Based on Pierre Gy’s theory of sampling (TOS), the correct extraction of an increment when composing a sample must give all particles the same chance of being selected. Aiming to comply with the theory of sampling, sampler construction parameters must be considered to avoid increment delimitation and extraction errors (IDE and IEE). In this way, a detailed study of the ore physical properties is necessary before designing sampling systems, which are customised for each application and ore type. Based on ore characterisation studies and combined with Discrete Element Method (DEM) simulations, it is possible to evaluate samplers’ dimensions as proposed by the theory of sampling and determine the best design and operational parameters. The present study investigated and optimised the performance of a secondary vezin sampler installed in the feed sampling system of a gold plant in Brazil using DEM. Full article
(This article belongs to the Special Issue Transfer Systems for Ores and Minerals)
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24 pages, 8308 KiB  
Article
Metallogenic Mechanism of Carlin-Type Gold Deposit in Zhen’an-Xunyang Basin, in the South Qinling of China: Constraints of In Situ Trace Elements and S Isotopes from Newly Discovered Wangzhuang Gold Deposit
Minerals 2023, 13(11), 1459; https://doi.org/10.3390/min13111459 - 20 Nov 2023
Viewed by 649
Abstract
The Zhen’an-Xunyang Basin is a late Paleozoic rifted basin with a series of Au-Hg-Sb deposits that have been found, mostly along the Nanyangshan fault. Recently discovered large- and medium-sized gold deposits such as the Xiaohe and Wangzhuang deposits exhibit typical characteristics of Carlin-type [...] Read more.
The Zhen’an-Xunyang Basin is a late Paleozoic rifted basin with a series of Au-Hg-Sb deposits that have been found, mostly along the Nanyangshan fault. Recently discovered large- and medium-sized gold deposits such as the Xiaohe and Wangzhuang deposits exhibit typical characteristics of Carlin-type gold deposits. Therefore, it is imperative to select a typical deposit for an in-depth study of its metallogenic mechanism to support future prospecting efforts targeting the Carlin-type gold deposits within the area. Based on detailed field investigation and microphotographic observation, four ore-forming stages are identified: I, low-sulfide quartz stage, characterized by euhedral, subhedral pyrite, and fine veins of quartz injected parallel to the strata; II, arsenopyrite–arsenian pyrite–quartz stage, the main mineralization stage characterized by strongly silicified zones of reticulated quartz, disseminated arsenopyrite, fine-grained pyrite; III, low-sulfide quartz stage, characterized by large quartz veins cutting through the ore body or fine veins of quartz; Ⅳ, carbonate–quartz stage, characterized by the appearance of a large number of calcite veins. In situ analysis of trace elements and S isotopes of typical metal sulfides was carried out. The results show significant variations in the trace element compositions of metal sulfides in different stages, among which the main mineralization stage differs notably from those of the Au- and As-low surrounding strata. In situ S isotope analysis reveals δ34S values ranging from 15.78‰ to 28.71‰ for stage I metal sulfides, 5.52‰ to 11.22‰ for stage II, and 0.3‰ to 5.25‰ for stage III, respectively, revealing a gradual decrease in S isotopic values from the pre-mineralization stage to post-mineralization stage, similar to those observed in the Xiaohe gold deposit. These features indicate a distinct injection of relatively low 34S hydrothermal fluids during the mineralization process. The element anomalies of the 1:50,000 stream sediment in the region revealed ore-forming element zonation changing in W→Au (W)→Hg, Sb (Au) anomalies from west to east, manifested by the discovery of tungsten, gold, and mercury–antimony deposits in the area. Moreover, conspicuous Cr-Ni-Ti-Co-Mo anomalies were observed on the western side of the Wangzhuang and Xiaohe gold deposits, indicating a potential concealed pluton related to these deposits. These lines of evidence point to a magmatic–hydrothermal origin for the Carlin-type gold deposits in this area. Furthermore, hydrothermal tungsten deposits, Carlin-type gold deposits, and low-temperature hydrothermal mercury–antimony deposits in this region are probably controlled by the same magma–hydrothermal system. Full article
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17 pages, 18311 KiB  
Article
Rare Earth Elements in the Shok-Karagay Ore Fields (Syrymbet Ore District, Northern Kazakhstan) and Visualisation of the Deposits Using the Geography Information System
Minerals 2023, 13(11), 1458; https://doi.org/10.3390/min13111458 - 20 Nov 2023
Viewed by 692
Abstract
Rare earth elements deposited in ion-adsorption clay-type deposits in Northern Kazakhstan were recognised using mineralogical and geochemical methods. The diversity and mineralogical properties of the Shok-Karagay deposit and Syrymbet ore fields under investigation in this study are closely related to the process of [...] Read more.
Rare earth elements deposited in ion-adsorption clay-type deposits in Northern Kazakhstan were recognised using mineralogical and geochemical methods. The diversity and mineralogical properties of the Shok-Karagay deposit and Syrymbet ore fields under investigation in this study are closely related to the process of the formation of the deposits as well as the deposits’ architecture. A combination of mineralogical research and digital technology (GIS) was used to characterise the deposits. Rare earth elements from the cerium series were found in the following quantities: La (in ppm), 43–200; Ce, 57–206; Sm, 100–300; Eu, 22–100. Yttrium-series elements were found in the following quantities: Y, 31–106; Gd, 100–200; Tb, 100–200; Dy, 0–300; Ho, 0–20; Er, 0–364; Tm, 0.28–0.85; Yb, 2.2–39; Lu, 0–200. The wireframe and block models indicated that the bodies’ forms were 1800 m wide, 3500 m long, and 20–40 m thick. The major REE group minerals in both bodies were monazite and xenotime, whereas the minor minerals included yttrium parisite, silicorabdophanite, thorite, and orangite; moreover, ilmenite and titanomagnetite were found. The 3D models that were constructed indicated that the mineralogy and geochemistry of the ore bodies played a determining role in the deposits’ architecture. Full article
(This article belongs to the Section Mineral Deposits)
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20 pages, 9627 KiB  
Article
U-Pb Geochronology, Geochemistry and Geological Significance of the Yongfeng Composite Granitic Pluton in Southern Jiangxi Province
Minerals 2023, 13(11), 1457; https://doi.org/10.3390/min13111457 - 20 Nov 2023
Viewed by 707
Abstract
The Yongfeng composite granitic pluton, located in the southern section of the Nanling area, is composed of the Yongfeng and Longshi biotite monzonitic granites. In order to reveal the genesis of this composite granitic pluton and its relationship with mineralization, this study conducted [...] Read more.
The Yongfeng composite granitic pluton, located in the southern section of the Nanling area, is composed of the Yongfeng and Longshi biotite monzonitic granites. In order to reveal the genesis of this composite granitic pluton and its relationship with mineralization, this study conducted zircon U-Pb dating, whole-rock major and trace element analysis, and biotite electron probe analysis. The results show that the Yongfeng composite granitic pluton is rich in silicon and alkali, weakly peraluminous, and poor in calcium and iron. It shows the enrichment of light rare earth elements and a significant fractionation of light and heavy rare earth elements. It also shows the enrichment of large ion lithophile elements and depletion of Ba, K, P, Eu, and Ti relative to the primitive mantle. The contents of TFe2O3, MgO, CaO, TiO2, and P2O5 are low and decrease with increasing SiO2 content. The Yongfeng composite granitic pluton does not contain alkaline dark minerals. Its average zircon saturation temperature is 776 °C, average TFe2O3/MgO is 4.81, and average Zr + Nb + Ce + Y is 280.6 ppm, which correspond to a highly fractionated I-type granite. The Yongfeng and Longshi granites were respectively formed at 152.0 ± 1.0 Ma–151.3 ± 1.1 Ma and 148.9 ± 1.2 Ma. They were formed in the extensional tectonic setting during the post-orogenic stage, under the control of the breakup or retreat of the backplate after the subduction of the Pacific Plate into the Nanling hinterland. The magmatic system of the Yongfeng composite granitic pluton is characterized by high fractionation, high content of F, high temperature, and low oxygen fugacity, which is conducive to mineralization of Sn, Mo, and fluorite. Full article
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27 pages, 20880 KiB  
Article
Geochemical Evidence for Genesis of Nb–Ta–Be Rare Metal Mineralization in Highly Fractionated Leucogranites at the Lalong Dome, Tethyan Himalaya, China
Minerals 2023, 13(11), 1456; https://doi.org/10.3390/min13111456 - 19 Nov 2023
Viewed by 794
Abstract
Leucogranites in the Lalong Dome are composed of two-mica granite, muscovite granite, albite granite, and pegmatite from core to rim. Albite granite-type Be–Nb–Ta rare metal ore bodies are hosted by albite granite and pegmatite. Based on field and petrographic observations and whole-rock geochemical [...] Read more.
Leucogranites in the Lalong Dome are composed of two-mica granite, muscovite granite, albite granite, and pegmatite from core to rim. Albite granite-type Be–Nb–Ta rare metal ore bodies are hosted by albite granite and pegmatite. Based on field and petrographic observations and whole-rock geochemical data, highly differentiated leucogranites have been identified in the Lalong Dome. Two-mica granites, albite granites, and pegmatites yielded monazite ages of 23.6 Ma, 21.9 Ma, and 20.6 Ma, respectively. The timing of rare metal mineralization is 20.9 Ma using U–Pb columbite dating. Leucogranites have the following characteristics: high SiO2 content (>73 wt.%); peraluminosity with high Al2O3 content (13.6–15.2 wt.%) and A/CNK (mostly > 1.1); low TiO2, CaO, and MgO content; enrichment of Rb, Th, and U; depletion of Ba, Nb, Zr, Sr, and Ti; strong negative Eu anomalies; low εNd(t) values ranging from −12.7 to −9.77. These features show that the leucogranites are crust-derived high-potassium calc-alkaline and peraluminous S-type granites derived from muscovite dehydration melting under the water-absent condition, which possibly resulted from structural decompression responding to the activity of the South Tibetan detachment system (STDS). Geochemical data imply a continuous magma fractional crystallization process from two-mica granites through muscovite granites to albite granites and pegmatites. The differentiation index (Di) gradually strengthens from two-mica granite, muscovite granite, and albite granite to pegmatite, in which albite granite and pegmatite are highest (Di = 94). The Nb/Ta and Zr/Hf ratios of albite granite and pegmatite were less than 5 and 18, respectively, which suggests that albite granite and pegmatite belong to rare metal granites and have excellent potential for rare metal mineralization. Full article
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18 pages, 23288 KiB  
Article
Reservoir Characteristics and Main Factors Controlling Carboniferous Volcanic Rocks in the Well CH471 Area of the Hongche Fault Zone: Northwest Margin of Junggar Basin, China
Minerals 2023, 13(11), 1455; https://doi.org/10.3390/min13111455 - 19 Nov 2023
Viewed by 713
Abstract
Nearly 100 million tons of reserves have been explored in the Well 471 area of the Hongche Fault zone. The Carboniferous volcanic rock reservoir is the main oil-bearing reservoir in the well CH471 area and is the main target of exploration and development. [...] Read more.
Nearly 100 million tons of reserves have been explored in the Well 471 area of the Hongche Fault zone. The Carboniferous volcanic rock reservoir is the main oil-bearing reservoir in the well CH471 area and is the main target of exploration and development. The characteristics of the Carboniferous volcanic rock reservoir are studied through core, thin section, physical property, logging, and other data, and its main controlling factors are analyzed in combination with actual means of production. The lithologies of the volcanic reservoir in the study area are mainly volcanic breccia, andesite, and basalt. The matrix physical properties of volcanic rock reservoirs are medium-porosity and ultralow-permeability, among which volcanic breccia has the best physical properties. The reservoir space mainly comprises primary pores, secondary dissolution pores, and fractures, resulting in a dual medium pore-fracture-type reservoir. Combined with production data analysis, the lateral distribution of oil and gas is controlled by lithology and lithofacies, with explosive volcanic breccia being the best, followed by the basalt and andesite of overflow facies, which are vertically affected by weathering and leaching and distributed within 50~300 m from the top of the Carboniferous system. The area with densely developed fractures was conducive to developing high-quality reservoirs. The tectonic movement promoted the formation of weathering and controlled the development of faults. Based on a comprehensive analysis, it is believed that the formation of Carboniferous volcanic oil and gas reservoirs in the study area was controlled and influenced by the lithology, lithofacies, weathering, leaching, faults (fractures), and tectonics. Full article
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33 pages, 1796 KiB  
Review
Remining for Renewable Energy Metals: A Review of Characterization Needs, Resource Estimates, and Potential Environmental Effects
Minerals 2023, 13(11), 1454; https://doi.org/10.3390/min13111454 - 18 Nov 2023
Viewed by 1282
Abstract
Remining has been researched for decades, but its potential to supplement virgin extraction is currently unknown. This review addresses the remining of tailings/waste rock, coal residues, and byproduct and primary production materials for renewable energy metals (e.g., Co, Ni, REEs, Mn, Li). Geochemical [...] Read more.
Remining has been researched for decades, but its potential to supplement virgin extraction is currently unknown. This review addresses the remining of tailings/waste rock, coal residues, and byproduct and primary production materials for renewable energy metals (e.g., Co, Ni, REEs, Mn, Li). Geochemical characterization methods for estimating pollution potential must be supplemented with mineral liberation analysis and process testing to reliably estimate remining’s economic potential. National and regional remining characterization efforts currently exist in the U.S., Europe, Australia, and China but will take years to produce viable operations at scale. Tailings hold the most promise due to their large amounts worldwide and the fact that they are already extracted and pre-processed, which reduces energy and water use. Of the processing approaches examined, bioleaching appears to offer the most benefits with the fewest potential downsides. The advantages and challenges of the processing methods and remining sources are presented. Best remining practices are urgently needed to improve resource estimates and avoid impacts such as the tailings dam failures that occurred at remining operations in Romania and South Africa. Interest in remining is booming because it can increase domestic supply. If properly conducted, remining can also improve circularity and environmental conditions in areas affected by existing and legacy mining activity. Full article
(This article belongs to the Special Issue Reutilization and Valorization of Mine Waste, Volume II)
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29 pages, 58610 KiB  
Article
Geospatial Insights into Ophiolitic Complexes in the Cimmerian Realm of the Afghan Central Block (Middle Afghanistan)
Minerals 2023, 13(11), 1453; https://doi.org/10.3390/min13111453 - 18 Nov 2023
Viewed by 1454
Abstract
Ophiolites are remnants of oceanic crust that have been thrust onto continental crust due to tectonic processes. They are composed of mostly mafic and ultramafic rocks, which are genetically associated with gold, silver, platinum group element (PGE), chrome, manganese, titanium, cobalt, copper, and [...] Read more.
Ophiolites are remnants of oceanic crust that have been thrust onto continental crust due to tectonic processes. They are composed of mostly mafic and ultramafic rocks, which are genetically associated with gold, silver, platinum group element (PGE), chrome, manganese, titanium, cobalt, copper, and nickel deposits. The main objective of this research was to identify the spatial distribution of Mesozoic ophiolitic complexes within the Central Afghan Block in Middle Afghanistan using optical remote sensing data and spectral analyses. Distinct algorithms, such as false color composite (FCC), proposed band ratios (PBR), principal component analysis (PCA), and spectral angle mapper (SAM), were used to map the targeted ophiolitic complexes. New band ratios were proposed in this study based on the spectral properties of mafic-ultramafic minerals and rocks, which showed high efficiency. Based on the results, four different ophiolitic complexes were delineated within this study area. These complexes are consistent with previous studies. The accuracy assessment of this study showed an overall accuracy of 72.2%. The findings of this study can significantly contribute to further studies on the emplacement mechanism and paleo-Tethys history of Middle Afghanistan. Also, the spatial distribution of the ophiolitic complexes identified in this study can be used to constrain models of the tectonic evolution of the Central Afghan Block. Additionally, the identification of new band ratios for mapping ophiolitic complexes can be used in future studies of other ophiolite-bearing regions. Full article
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17 pages, 7279 KiB  
Article
An Intensity Tensor and Electric Field Gradient Tensor for Fe3+ at M1 Sites of Aegirine–Augite Using Single-Crystal Mössbauer Spectroscopy
Minerals 2023, 13(11), 1452; https://doi.org/10.3390/min13111452 - 18 Nov 2023
Viewed by 560
Abstract
An intensity tensor of quadrupole doublets and an electric field gradient tensor for Fe3+ at M1 sites in aegirine–augite ((Ca0.16Na0.86)∑1.02(Mg0.13Fe2+0.04Fe3+0.72 Al0.07)∑0.96Si2.01O6 [...] Read more.
An intensity tensor of quadrupole doublets and an electric field gradient tensor for Fe3+ at M1 sites in aegirine–augite ((Ca0.16Na0.86)∑1.02(Mg0.13Fe2+0.04Fe3+0.72 Al0.07)∑0.96Si2.01O6) are determined using single-crystal Mössbauer spectroscopy. The components of the intensity tensor are IXX = 0.670 (19), IYY = 0.353 (14), IXY = −0.113 (37) and IZZ = 0.477 (33). The components of the electric field gradient tensor (VXX, VYY and VZZ) for Fe3+ at M1 sites in aegirine–augite are −5.96 × 109, −4.65 × 1010 and 5.23 × 1010 C/m3, respectively. Comparisons of the intensity tensor of aegirine–augite with those of aegirine and augite (Wo40En45Fs16) that have already been reported and the IXX, IYY, IXY and IZZ intensity tensor components of aegirine–augite in this study are almost the same as those of aegirine, but different from those of augite. While the M2 sites of aegirine–augite and aegirine are fully occupied with Na+ and Ca2+ ions, the M2 sites of augite are not fully occupied with Ca2+. The compositional dependency of the intensity tensor components suggests that the intensity tensor components for Fe3+ at the M1 site of a solid solution between aegirine and augite are dependent on the occupancy of large cations such as Ca2+ and Na+ at M2 sites. Full article
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22 pages, 6705 KiB  
Article
Diagenetic Evolution Sequence and Pore Evolution Characteristics: Study on Marine-Continental Transitional Facies Shale in Southeastern Sichuan Basin
Minerals 2023, 13(11), 1451; https://doi.org/10.3390/min13111451 - 18 Nov 2023
Cited by 1 | Viewed by 721
Abstract
Diagenesis and pore structure are essential factors for reservoir evaluation. marine-continental transitional facies shale is a new shale gas reservoir of concern in the Sichuan Basin. The research on its diagenesis pore evolution model has important guiding significance in its later exploration and [...] Read more.
Diagenesis and pore structure are essential factors for reservoir evaluation. marine-continental transitional facies shale is a new shale gas reservoir of concern in the Sichuan Basin. The research on its diagenesis pore evolution model has important guiding significance in its later exploration and development. However, the current research on pore structure changes, diagenesis, and the evolution of marine-continental transitional facies shale is not sufficient and systematic. In order to reveal the internal relationship between pore structure changes and diagenesis, the evolution of marine-continental transitional facies shale was tested by X-ray diffraction, field emission scanning electron microscopy, low-pressure gas adsorption, nuclear magnetic resonance, and the diagenetic evolution sequence and nanopore system evolution of Longtan Formation shale was systematically studied. The results show that the Longtan Formation shale underwent short-term shallow after sedimentation, followed by long-term deep burial. The main diagenetic mechanisms of the Longtan Formation shale include compaction, dissolution, cementation, thermal maturation of organic matter, and transformation of clay minerals, which are generally in the middle-late diagenetic stage. The pore structure undergoes significant changes with increasing maturity, with the pore volumes of both micropores and mesopores reaching their minimum values at Ro = 1.43% and subsequently increasing. The change process of a specific surface area is similar to that of pore volumes. Finally, the diagenetic pore evolution model of Longtan Formation MCFS in Southeastern Sichuan was established. Full article
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36 pages, 3966 KiB  
Review
Soft Computing Application in Mining, Mineral Processing and Metallurgy with an Approach to Using It in Mineral Waste Disposal
Minerals 2023, 13(11), 1450; https://doi.org/10.3390/min13111450 - 17 Nov 2023
Viewed by 990
Abstract
In the past two decades, the mining sector has increasingly embraced simulation and modelling techniques for decision-making processes. This adoption has facilitated enhanced process control and optimisation, enabling access to valuable data such as precise granulometry measurements, improved recovery rates, and the ability [...] Read more.
In the past two decades, the mining sector has increasingly embraced simulation and modelling techniques for decision-making processes. This adoption has facilitated enhanced process control and optimisation, enabling access to valuable data such as precise granulometry measurements, improved recovery rates, and the ability to forecast outcomes. Soft computing techniques, such as artificial neural networks and fuzzy algorithms, have emerged as viable alternatives to traditional statistical approaches, where the complex and non-linear nature of the mineral processing stages requires careful selection. This research examines the up-to-date use of soft computing techniques within the mining sector, with a specific emphasis on comminution, flotation, and pyrometallurgical and hydrometallurgical processes, and the selection of soft computing techniques and strategies for identifying key variables. From this, a soft computing approach is presented to enhance the monitoring and prediction accuracy for mineral waste disposal, specifically focusing on tailings and spent heap leaching spoils database treatment. However, the accessibility and quality of data are crucial for the long-term application of soft computing technology in the mining industry. Further research is needed to explore the full potential of soft computing techniques and to address specific challenges in mining and mineral processing. Full article
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17 pages, 8772 KiB  
Article
Geochemical and Mineralogical Characteristics of Ion-Adsorption Type REE Mineralization in the Mosuoying Granite, Panxi Area, Southwest China
Minerals 2023, 13(11), 1449; https://doi.org/10.3390/min13111449 - 17 Nov 2023
Cited by 1 | Viewed by 749
Abstract
The ion-adsorption rare earth deposit developed on the Mosuoying granite in the Panxi area of southwestern China represents a significant advancement in the exploration of ion-adsorption rare earth deposits in Sichuan. Being the first and currently the sole ion-adsorption rare earth deposit in [...] Read more.
The ion-adsorption rare earth deposit developed on the Mosuoying granite in the Panxi area of southwestern China represents a significant advancement in the exploration of ion-adsorption rare earth deposits in Sichuan. Being the first and currently the sole ion-adsorption rare earth deposit in Sichuan, studying its rare earth mineralization characteristics holds great importance. This paper aims to investigate the geochemical properties of the Mosuoying granite and its overlying weathered crust using rock geochemical methods based on field geological investigations. The findings reveal that the deposit belongs to the light rare earth type, with the ore-forming parent rock attributed to the high-potassium calc-alkaline series. It exhibits a high rock REE content ranging from 419 to 578 ppm, indicating favorable mineralization potential. Hydrothermal alteration reduces the REE content of the parent rock, leading to a notable increase in the LREE/HREE ratio, thus impacting the partitioning of rare earth elements and subsequent ore formation. The distribution characteristics of rare earth elements in each layer of the weathered crust are controlled by the parent rock and exhibit a light rare earth distribution pattern. The completely weathered layer is the main enrichment zone for rare earth elements, and the migration and enrichment patterns of rare earth elements in the weathered crust are evident. From the semi-weathered layer to the completely weathered layer, all REEs were gained, with a higher degree of migration for LREE. From the completely weathered layer to the clay layer, all REEs were lost, and the vertical distribution of rare earth content shows a “low-high-low” pattern. Full article
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12 pages, 2968 KiB  
Article
Effects of Short-Term Acidification on the Adsorption of Dissolved Organic Matter by Soil Minerals and Its Mechanism of Action
Minerals 2023, 13(11), 1448; https://doi.org/10.3390/min13111448 - 17 Nov 2023
Viewed by 600
Abstract
In order to investigate the impact of soil acidification on the adsorption of dissolved organic matter by soil minerals and understand its mechanism, this study selected commonly found minerals in soils, namely illite, kaolin, and hematite, as the research objects. Glucose and tannic [...] Read more.
In order to investigate the impact of soil acidification on the adsorption of dissolved organic matter by soil minerals and understand its mechanism, this study selected commonly found minerals in soils, namely illite, kaolin, and hematite, as the research objects. Glucose and tannic acid were considered as the representative compounds for studying the adsorption of dissolved organic matter in soils. By analyzing the effects of the three minerals on the adsorption characteristics of glucose and tannic acid after a short-term acidification treatment, this study aimed to explore the underlying mechanism. To achieve this, scanning electron microscopy and a specific surface area analyzer were utilized. The results of this study indicate that the adsorption modes of the minerals studied were unaffected by short-term acidification. Chemisorption, as well as surface and mesopore diffusion, were found to dominate the adsorption process. In terms of adsorption behavior, the minerals exhibited multilayer inhomogeneous adsorption with glucose and kaolin, while tannic acid showed monolayer adsorption with illite and hematite. When exposed to the same acidification conditions, the saturated adsorption of glucose and tannic acid was found to be illite ≥ hematite > kaolin. The kinetic adsorption processes exhibited three stages: fast adsorption, slow adsorption, and adsorption equilibrium. Interestingly, as the intensity of the acidification increased, the saturated adsorption capacity generally followed the trend of S3 (test minerals with pH adjusted to 3 value) > S5 (test minerals with pH adjusted to 5 value) > CK (the control group). The acidification-induced solvation led to an increase in the specific surface area and the number of active adsorption sites on the minerals. Additionally, the protonation reaction triggered a change in the surface charge, which in turn affected the hydrogen bonding, ligand exchange, and charge transfer between the minerals and glucose and tannic acids. These interactions ultimately enhanced the adsorption capacity. Full article
(This article belongs to the Section Environmental Mineralogy and Biogeochemistry)
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13 pages, 2999 KiB  
Article
The Presence of Wodginite in Lithium–Fluorine Granites as an Indicator of Tantalum and Tin Mineralization: A Study of Abu Dabbab and Nuweibi Massifs (Egypt)
Minerals 2023, 13(11), 1447; https://doi.org/10.3390/min13111447 - 16 Nov 2023
Viewed by 898
Abstract
This study examines the accessory wodginite and the discovery of titanium-bearing wodginite and Fe and Ti-bearing wodginite in lithium-fluorine granites from the Abu Dabbab and Nuweibi massifs in Eastern Egypt. The wodginite group’s mineral association includes tantalum-bearing cassiterite and tin-bearing tantalum–niobate minerals: tantalite-(Mn), [...] Read more.
This study examines the accessory wodginite and the discovery of titanium-bearing wodginite and Fe and Ti-bearing wodginite in lithium-fluorine granites from the Abu Dabbab and Nuweibi massifs in Eastern Egypt. The wodginite group’s mineral association includes tantalum-bearing cassiterite and tin-bearing tantalum–niobate minerals: tantalite-(Mn), columbite-(Mn), and microlite. Three forms of wodginite crystallization were identified: (1) rims around columbite-(Mn) and tantalite-(Mn) varying from 1.5 to 21.9 μm in thickness, (2) micro-inclusions in cassiterite ranging from 5.4 to 27.0 μm in size, and (3) autonomous crystals measuring 3–124 μm in length. Wodginite in the Nuweibi massif is mainly found in porphyritic granite of late-stage porphyry intrusion. It has a similar composition to the worldwide wodginite of rare-metal granites, but exhibits a lower content of TiO2 (average 0.54%) and is a mineral indicator of rich tantalum ore deposits. In contrast, wodginite in the Abu Dabbab massif is replaced by titanium-bearing wodginite (Ti/(Sn + BTa + Ti + Fe3+) = 0.23) and is associated with Fe and Ti-bearing wodginite. Wodginite and Ti-bearing wodginite are maximally enriched in manganese (Mn/(Mn + Fe2+ +Ca) = 0.95), expressed in all intrusive phases of the massif, and are mineral indicators of tantalum-bearing granites with associated cassiterite-quartz mineralization. Full article
(This article belongs to the Special Issue Genesis, Geochemistry and Mineralization of Metallic Minerals)
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20 pages, 6610 KiB  
Article
Late Cryogenian Circum-Rodinia Syn-Subduction Extension: Insights from Highly Fractionated S-Type and A-Type Granitoids in the Northern Tarim Craton
Minerals 2023, 13(11), 1446; https://doi.org/10.3390/min13111446 - 16 Nov 2023
Viewed by 678
Abstract
Late Cryogenian–Ediacaran magmatism represents the latest Precambrian tectonothermal event in the Tarim Craton. However, its geodynamic setting and geological significance are controversial. Here, we report the geochronology, whole-rock geochemistry, and Sr-Nd-Hf isotopic compositions of newly identified late Cryogenian A-type and highly fractionated S-type [...] Read more.
Late Cryogenian–Ediacaran magmatism represents the latest Precambrian tectonothermal event in the Tarim Craton. However, its geodynamic setting and geological significance are controversial. Here, we report the geochronology, whole-rock geochemistry, and Sr-Nd-Hf isotopic compositions of newly identified late Cryogenian A-type and highly fractionated S-type granites from two locations in the northern Tarim Craton. LA-ICP-MS zircon U-Pb analyses yield ages of 642 ± 7 Ma for a syenogranite and 643 ± 4.5 Ma for a mylonitized granite. The syenogranite is weakly peraluminous and shows an A-type granite affinity, as indicated by its high K2O + Na2O contents (8.35–8.64 wt.%), high field strength elements (Zr + Nb + Ce + Y = 435.8 − 463.4 × 10−6), Ga/Al ratios (2.79−2.83), and zircon saturation temperatures (829–844 °C). In contrast, the mylonitized granite contains Al-oversaturated minerals (e.g., garnet) and has high a differentiation index (DI = of 98.9–99.4), with lower zircon saturation temperatures (786–792 °C); the samples display high SiO2 contents (72.99–74.00 wt.%) and A/CNK values (1.16–1.17) and low Nb/Ta and Zr/Hf ratios and are enriched in Rb and depleted in Ba, Sr, which all point to a highly fractionated S-type granite affinity. The granites are characterized by elevated large-ion lithosphere elements (LILEs) and flat high-field-strength elements (HFSEs) patterns, with deep Nb and Ta troughs and pronounced negative Eu anomalies (Eu/Eu* = 0.17–0.38). They show apparently negative εNd(t) values (−10.1 to −9.8 and −6.8 to −7.9, respectively) and εHf(t) values (−9.66 to −1.77 and −33.5 to −1.3, respectively) with Paleoproterozoic crustal model ages, indicating that they were mainly generated by the partial melting of mature crustal materials with a minor contribution from a mantle-derived magmatic source. By integrating with previously published geological, sedimentological, and structural data, we suggest that the granites formed due to a high-temperature gradient in a syn-subduction extensional setting that was probably induced by northward slab rollback of the Paleo-Asian Oceanic lithosphere. Our new data highlight an upper-plate extension in the northern Tarim Craton that constitutes the northern periphery of the Rodinia supercontinent. The linear distribution of late Cryogenian magmatic rocks provides critical evidence for the orogen strike extension of the terminal suture between the Tarim Craton and southwestern Altaids. Full article
(This article belongs to the Section Mineral Geochemistry and Geochronology)
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30 pages, 15532 KiB  
Review
Dry Stacking of Filtered Tailings for Large-Scale Production Rates over 100,000 Metric Tons per Day: Envisioning the Sustainable Future of Mine Tailings Storage Facilities
Minerals 2023, 13(11), 1445; https://doi.org/10.3390/min13111445 - 16 Nov 2023
Viewed by 1708
Abstract
Communities and authorities have been dismayed by globally recorded tailings storage facility (TSF) failures in recent years, which have negatively affected the safety of people and the integrity of the environment. In this context, obtaining the social and environmental license to operate TSFs [...] Read more.
Communities and authorities have been dismayed by globally recorded tailings storage facility (TSF) failures in recent years, which have negatively affected the safety of people and the integrity of the environment. In this context, obtaining the social and environmental license to operate TSFs has become a challenging process for mining companies. This has promoted the trend of using mine tailings dewatering technologies in the mining industry, with dry stacking of filtered mine tailings being recognized worldwide as one of the most acceptable, safe, and environmentally friendly solutions. This article presents a new paradigm in managing mine tailings, with disruptive and futuristic characteristics, considering the dry stacking of filtered mine tailings for large-scale industrial production rates over 100,000 metric tons per day (mtpd). Aspects of filtered tailings management are discussed, such as (i) dewatering process plant with thickening/filtering equipment, (ii) conveyance using fixed and movable conveyor belts, (iii) construction of dry stacking of filtered mine tailings facility, and (iv) implementation of Industry 4.0 technologies for automation of the mining processes. Finally, the article discusses how the large-scale filtered mine tailings solution is applied, considering the advances in the equipment’s performance and implementation of Industry 4.0 technologies as well as the experience gained worldwide in several mining operations. The future global trend is that mining operations with high daily production of mine tailings will apply dry stacking technology without dams to guarantee sustainability, promote continuity of the mining business, ensure the safety of communities, and conserve the environment. Full article
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22 pages, 12690 KiB  
Article
Geochemical Overprinting and Secondary Placer Crystal Formation in the La Cholla District, Quartzsite, Arizona, USA: Evidence from Copper Isotopes, Morphology, and Trace Elements
Minerals 2023, 13(11), 1444; https://doi.org/10.3390/min13111444 - 15 Nov 2023
Viewed by 707
Abstract
Geochemical overprinting on placer gold deposits produces complex deposits with apparently paradoxical geochemical and morphological attributes. The La Cholla placer gold deposits near Quartzsite, Arizona, USA, contain sharp and often undamaged gold crystals within high-energy gravels as a result of postdepositional recrystallization by [...] Read more.
Geochemical overprinting on placer gold deposits produces complex deposits with apparently paradoxical geochemical and morphological attributes. The La Cholla placer gold deposits near Quartzsite, Arizona, USA, contain sharp and often undamaged gold crystals within high-energy gravels as a result of postdepositional recrystallization by localized hot springs. Geothermal fluids emanated from a basin-bounding fault and left a distinct signature that includes recrystallized gold with low Pb and δ65Cu > 1.14‰, secondary uraninite and carnotite, travertine deposits, and mounds of highly silicified placer gravels. Surrounding these deposits are placer gravels with angular gold morphology and geochemistry indicative of flash-flood pulse placers with a lode gold source < 5 km and gold particles with low Pb and δ65Cu < 0.77‰. The multitude of small local lode gold source veins is likely related to specialized fluid migration along mid-Tertiary detachment faults. The unroofing of these veins at 5 to 17 Ma by high-angle Basin and Range faulting led to extensive placer development, with subsequent localized modification by geothermal fluid migration along the same faults. This study documents geochemical overprinting and modification of placer deposits and bears upon the study of other placers containing crystalline gold and uranium mineralization. Similar deposits may document past geothermal activity and identify structural fluid conduits and steep paleo-topographic gradients. Full article
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20 pages, 7601 KiB  
Article
Sources of Metallogenic Materials of the Saima Alkaline Rock-Hosted Niobium–Tantalum Deposit in the Liaoning Region: Evidence from the Sr-Nd-Pb and Li Isotopes
Minerals 2023, 13(11), 1443; https://doi.org/10.3390/min13111443 - 15 Nov 2023
Viewed by 642
Abstract
The Saima alkaline rock-hosted niobium–tantalum deposit (hereafter referred to as the Saima Deposit) is situated in the Liaodong Peninsula, which constitutes the eastern segment of the northern margin of the North China Craton. The rock types of the Saima Deposit include phonolite, nepheline [...] Read more.
The Saima alkaline rock-hosted niobium–tantalum deposit (hereafter referred to as the Saima Deposit) is situated in the Liaodong Peninsula, which constitutes the eastern segment of the northern margin of the North China Craton. The rock types of the Saima Deposit include phonolite, nepheline syenite, and aegirine nepheline syenite, which hosts niobium–tantalum ore bodies. In this study, the primary niobium-bearing minerals identified include loparite, betafite, and fersmite. The Saima pluton is characterized as a potassium-rich, low-sodium, and peraluminous alkaline pluton. Trace element characteristics reveal that the metallization-associated syenite is enriched in large-ion lithophile elements (LILEs) such as K and Rb but is relatively depleted in high-field strength elements (HFSEs). As indicated by the rare earth element (REE) profile, the Saima pluton exhibits a high total REE content (∑REE), dominance of light REEs (LREEs), and scarcity of heavy REEs (HREEs). The Sr-Nd-Pd isotopic data suggest that aegirine nepheline syenite and nepheline syenite share consistent isotopic signatures, indicating a common origin. The Saima alkaline pluton displays elevated ISr values ranging from 0.70712 to 0.70832 coupled with low εNd(t) values between −12.84 and −11.86 and two-stage model ages (tDM2) from 1967 to 2047 Ma. These findings indicate that the metallogenic materials for the Saima Deposit derive from both an enriched mantle source and some crustal components. The lithium (Li) isotopic fractionation observed during the genesis of the Saima pluton could be attributed to the differential diffusion rates of 6Li and 7Li under non-equilibrium fluid–rock interactions. Full article
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26 pages, 61394 KiB  
Article
Characteristics and Controlling Factors of Pores in Different Shale Lithofacies Reservoirs of Lower Cambrian Qiongzhusi Formation, Southwestern Sichuan Basin, China
Minerals 2023, 13(11), 1442; https://doi.org/10.3390/min13111442 - 15 Nov 2023
Viewed by 620
Abstract
The shale reservoirs of the Lower Cambrian Qiongzhusi Formation are widely distributed in the Sichuan Basin and have abundant gas resources. However, the shale lithofacies of the Qiongzhusi Formation are complex due to frequent sea level changes. The reservoir pore structure characteristics and [...] Read more.
The shale reservoirs of the Lower Cambrian Qiongzhusi Formation are widely distributed in the Sichuan Basin and have abundant gas resources. However, the shale lithofacies of the Qiongzhusi Formation are complex due to frequent sea level changes. The reservoir pore structure characteristics and gas content of different shale lithofacies vary significantly, which makes identifying the ‘sweet spot’ a challenging task. In this study, core observation and X-ray diffraction (XRD) were used to analyze the lithofacies types and characteristics of the study area. The pore types of different shale lithofacies were observed using field emission-scanning electron microscopy. Pore structures were studied using low-temperature gas (including N2 and CO2) physisorption, and the pore volume (PV), specific surface area (SSA) and pore structure were systematically characterized. The primary factors influencing pore formation in different types of shale lithofacies were analyzed by combining geochemical experiments and mineral contents. The results indicate that the lithofacies of the Qiongzhusi Formation shale in the study area can be classified into five categories according to mineral compositions: Siliceous argillaceous shale (CM-1), Argillaceous siliceous mixed shale (M-2), Argillaceous siliceous shale (S-3), Siliceous rock (S) and Calcareous siliceous shale (S-2). Pores are abundant in S-3 shale, M-2 shale and CM-1 shale. The S-3 shale is more enriched in organic pores and clay mineral pores compared to other lithofacies shales, and the pore morphology is mainly wedge-shaped and plate-like. M-2 shale and CM-1 shale are rich in clay minerals and mainly develop clay mineral pores and are mainly wedge-shaped and plate-like. The S shale and S-2 shale mainly develop interparticle pores and clay mineral pores, which are mainly slit-like. The results show that TOC, pyrite content, quartz and feldspar mineral content, clay mineral type and content affect the pore structure in the study area. Quartz and feldspar content have a negative effect on micropore and mesopore volumes. TOCs have a weak positive correlation with micropore volume and micropore SSA. Clay mineral content has significant positive effects on the PV and SSA of micropores and mesopores, indicating that clay mineral content is the main factor affecting the pore structure of shale. Full article
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25 pages, 6134 KiB  
Article
Geochemical and Isotopic Fractionation in the Hypogene Ore, Gossan, and Saprolite of the Alvo 118 Deposit: Implications for Copper Exploration in the Regolith of the Carajás Mineral Province
Minerals 2023, 13(11), 1441; https://doi.org/10.3390/min13111441 - 15 Nov 2023
Viewed by 651
Abstract
In the Carajás Mineral Province, gossan formation and lateritization have produced numerous supergene orebodies at the expense of IOCG deposits and host rocks. The Alvo 118 deposit comprises massive and disseminated hypogene copper sulfides associated with gossan and mineralized saprolites. The hypogene reserves [...] Read more.
In the Carajás Mineral Province, gossan formation and lateritization have produced numerous supergene orebodies at the expense of IOCG deposits and host rocks. The Alvo 118 deposit comprises massive and disseminated hypogene copper sulfides associated with gossan and mineralized saprolites. The hypogene reserves are 170 Mt, with 1% Cu and 0.3 ppm Au, while the supergenes are 55 Mt, comprised of 30% gossan and 70% saprolite, with 0.92% Cu and 0.03 ppm Au. The gossan includes goethite, malachite, cuprite, and libethenite zones. The saprolite comprises kaolinite, vermiculite, smectite, and relics of chlorite. In the hypogene mineralization, Ag, Te, Pb, Se, Bi, Au, In, Y, Sn, and U are mainly hosted by chalcopyrite and petzite, altaite, galena, uraninite, stannite, and cassiterite. In the gossan, Ag, Te, Pb, Se, and Bi are hosted by Cu minerals, while Au, In, Y, Sn, and U are associated with iron oxyhydroxides, in addition to Zn, As, Be, Ga, Ga, Mo, Ni, and Sc. As supporting information, δ65Cu values indicate that the gossan is immature and, at least partly, not affected by leaching. In the saprolite, Ga, Sc, Sn, V, Mn, Co, and Cr are associated with the iron oxyhydroxides, partially derived from the host rock weathering. The δ56Fe values indicate that hypogene low contribution of the hypogene mineralization to the saprolite iron content. The association of Al2O3, Hf, Zr, Th, TiO2, Ce, La, Ba, and Sr represents the geochemical signature of the host rocks, with dominant contributions from chlorites, while In, Y, Te, Pb, Bi, and Se are the main pathfinders of Cu mineralization. Full article
(This article belongs to the Special Issue Mineral Evolution and Mineralization during Weathering)
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35 pages, 6512 KiB  
Article
Petrology and Geochemistry of Mesoarchean Sukinda Ultramafics, Southern Singhbhum Odisha Craton, India: Implications for Mantle Resources and the Geodynamic Setting
Minerals 2023, 13(11), 1440; https://doi.org/10.3390/min13111440 - 14 Nov 2023
Viewed by 553
Abstract
The Sukinda ultramafic complex in India comprises precisely two areas: Kaliapani (KLPN) and Katpal (KTPL). These areas consist of a sequence of lithotypes, including orthopyroxenite, dunite, serpentinite, and chromitite, displaying a rhythmic layering of rocks. These rocks exhibit a cumulate texture and stand [...] Read more.
The Sukinda ultramafic complex in India comprises precisely two areas: Kaliapani (KLPN) and Katpal (KTPL). These areas consist of a sequence of lithotypes, including orthopyroxenite, dunite, serpentinite, and chromitite, displaying a rhythmic layering of rocks. These rocks exhibit a cumulate texture and stand out due to their elevated Mg# (78.43–93.20), Cr (905.40–58,799 ppm), Ni (193.81–2790 ppm), Al2O3/TiO2 (27.01–74.06), and Zr/Hf (39.81–55.24) ratios, while possessing lower TiO2 contents (0.01–0.12 wt%). These ultramafics, characterized by low Ti/V (0.83–19.23) and Ti/Sc (7.14–83.72) ratios, negative anomalies of Zr, Hf, Nb, and Ti in a primitive mantle-normalized spider diagram, indicate that the ultramafics originate from a depleted mantle source. Furthermore, the presence of enriched LREE compared to HREE, a negative Eu anomaly, and enrichment of Th, U, and negative Nb anomalies suggest a subduction setting. The whole-rock geochemical data reveal high levels of MgO, Cr, and Ni, as well as low TiO2 and CaO/Al2O3 ratios and high Al2O3/TiO2 ratios. Moreover, the mineral chemistry data of the ultramafic rocks show high-Mg olivine (Fo 90.9−94.1) in dunite, high-Mg orthopyroxene (En 90.4–90.7) in orthopyroxenite, and high Cr# (0.68–0.82) and low Mg# (0.40–0.54) in chromite, alongside significant Al2O3 (9.93–12.86 wt%) and TiO2 (0.20–0.44 wt%) contents in the melt. Such geochemical characteristics strongly suggest that the Sukinda ultramafic originates from the fractional crystallization of a boninitic parental magma, which is derived from the second-stage melting in a depleted metasomatized mantle source within a supra-subduction zone tectonic setting. Full article
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22 pages, 7955 KiB  
Article
Paleoenvironmental Characteristics of Lacustrine Shale and Its Impact on Organic Matter Enrichment in Funing Formation of Subei Basin
Minerals 2023, 13(11), 1439; https://doi.org/10.3390/min13111439 - 14 Nov 2023
Viewed by 665
Abstract
Organic matter in depositional environment is the essential material for oil and gas generation. Total organic carbon (TOC) is one of the important parameters for estimating the hydrocarbon generation potential of shale oil and predicting sweet spots. The TOC of the second member [...] Read more.
Organic matter in depositional environment is the essential material for oil and gas generation. Total organic carbon (TOC) is one of the important parameters for estimating the hydrocarbon generation potential of shale oil and predicting sweet spots. The TOC of the second member of the Funing Formation (Ef2) ranges from 0.25% to 2.30%. TOC is higher in the upper shale and lower in the lower shale of the Funing Formation, showing a significant enrichment difference. However, there have been few reports on the study of the main controlling factors for the differential enrichment of organic matter in Ef2. This study aims to reconstruct the paleoenvironment of lacustrine shale in Ef2. Additionally, this study aims to clarify the influence of the paleoenvironment on the differential enrichment of organic matter in Ef2. For this purpose, systematic mineralogical and geochemical analyses were conducted on 72 samples from a representative well. The results indicate that, based on parameters such as paleoclimate (chemical index of alteration, CIA), paleosalinity (Sr/Ba), paleoredox conditions (Cu/Zn), paleoproductivity (P/Ti), water depth (Rb/K), and terrigenous clastic input (Al, Ti), the paleoenvironment during the deposition of the Ef2 shale clearly exhibited significant changes. During the early stage, the climate was hot and dry, with shallow water, weak chemical weathering, low productivity, and salinity ranging from saline to brackish. In the later stage, the climate became warm and humid, with deeper water, moderate chemical weathering, high productivity, and salinity ranging from brackish to freshwater. There are significant errors in directly using the Sr/Ba index to evaluate the paleosalinity of Ef2 shale. Carbonate minerals and calcium-rich bioclasts may increase the Sr/Ba ratio, and the corrected Sr element content is only 44.29% of the original sample. The enrichment of organic matter is clearly controlled by productivity levels and climatic conditions. The higher the paleoproductivity and the warmer and more humid the climate, the more enriched the organic matter becomes. Fundamental differences in paleoproductivity govern the enrichment of organic matter during the deposition process of the Ef2 shale. The organic matter enrichment pattern in the Ef2 shale represents a typical productivity model. Full article
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23 pages, 28707 KiB  
Article
Diagenetic Evolution of Upper Cretaceous Kawagarh Carbonates from Attock Hazara Fold and Thrust Belt, Pakistan
Minerals 2023, 13(11), 1438; https://doi.org/10.3390/min13111438 - 13 Nov 2023
Viewed by 623
Abstract
A recent hydrocarbons discovery in 2021 in the Kawagarh Formation has brought attention to the significance of sedimentology and specifically diagenesis for understanding and characterizing the reservoir properties. The diagenetic history and multiscale processes that contributed to diagenesis were vaguely known. This study [...] Read more.
A recent hydrocarbons discovery in 2021 in the Kawagarh Formation has brought attention to the significance of sedimentology and specifically diagenesis for understanding and characterizing the reservoir properties. The diagenetic history and multiscale processes that contributed to diagenesis were vaguely known. This study aimed to reconstruct various diagenetic phases, paragenetic sequences, and the interrelationship of these phases in the Kawagarh Formation. The diagenetic processes were identified and characterized through an integrated methodology utilizing the outcrop, petrographic, and geochemical analyses. Early calcite cementation was found to occur in the early stages of marine burial diagenesis involving pore fluid originating from the dissolution of aragonite in interlayer marl/mudstone beds and reprecipitating as microspar in adjacent limestone beds. The absence of mechanical compaction in wackstone and mudstone facies and the presence of late compaction in lithified packstones clearly imply that early calcite cementation occurred prior to compaction. Dolomitization with stylolites coupled with significant negative oxygen (δ18O) isotope values implies a fault-related hydrothermal dolomitization model. Uplift introduced the fractures and low Mg fresh fluids to the system which caused calcitisation in shallow burial settings. The depleted δ13C and negative δ18O values indicate the mixing of surface-derived waters with hot burial fluids during the calcitization. This study offers valuable insights into several aspects related to the formation and the basin itself, including burial depths, fluid influx, and geochemical gradients. It also sheds light on the evolution of reservoir properties such as porosity and permeability in dolomitization fronts. Such insights can be used to gain a deeper understanding about the burial history, basin evaluation, and reservoir characterization for hydrocarbon exploration. Full article
(This article belongs to the Special Issue Deposition, Diagenesis, and Geochemistry of Carbonate Sequences)
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19 pages, 24317 KiB  
Article
Mapping Leachate Pathways in Aging Mining Tailings Pond Using Electrical Resistivity Tomography
Minerals 2023, 13(11), 1437; https://doi.org/10.3390/min13111437 - 13 Nov 2023
Cited by 1 | Viewed by 761
Abstract
Mining activities often leave behind a legacy of environmental challenges, with aging tailings ponds representing a significant concern due to their potential for leachate formation and subsequent contaminant release. Thus, this study employs Electrical Resistivity Tomography (ERT) to investigate the intricate pathways of [...] Read more.
Mining activities often leave behind a legacy of environmental challenges, with aging tailings ponds representing a significant concern due to their potential for leachate formation and subsequent contaminant release. Thus, this study employs Electrical Resistivity Tomography (ERT) to investigate the intricate pathways of leachate within an aging mining tailings pond, addressing the pressing environmental and human health concerns associated with potential contaminant release. Ten 2D ERT profiles were acquired at the El Mochito mine waste site, covering an area of approximately half a square kilometer. These profiles, ranging in length from 104 to 363 m, provided insights into subsurface conditions down to a maximum depth of 60 m. The subsurface mapping of the ERT data showed three different geoelectric layers. The uppermost layer, with a thickness of approximately 2.5 m and resistivity values ranging from 60 to 100 Ohm.m, was identified as a dry tailing/soil zone. Beneath it, the second layer exhibited moderately resistive values (30–60 Ohm.m) with varying thicknesses of 10–20 m, signifying a percolation/leaching zone (semi-saturated zone). The third layer, characterized by substantially low resistivity (1–30 Ohm.m), indicated saturation and the presence of conductive materials, strongly suggesting active leaching. Based on these findings, this study recommends further investigation through geochemical analysis of subsurface samples and more advanced geophysical imaging techniques to validate the distribution of anomalous zones and delineate remediation pathways. This study lays the foundation for future comprehensive research that will integrate geophysical surveys with geochemical analysis and establish 4D modeling techniques to monitor pollutant penetration over time, with a particular focus on mine waste tailings mapping. Plus, this study contributes valuable insights into the characterization of leachate pathways within mining tailings ponds, offering a foundation for informed environmental management and remediation strategies. Full article
(This article belongs to the Special Issue Electrical Resistivity Imaging Applied to Mining Legacy Site)
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17 pages, 4224 KiB  
Article
Experimental Investigation into the Proportion of Cemented Aeolian Sand-Coal Gangue-Fly Ash Backfill on Mechanical and Rheological Properties
Minerals 2023, 13(11), 1436; https://doi.org/10.3390/min13111436 - 13 Nov 2023
Viewed by 715
Abstract
Aiming at the problems of large water secretion, poor suspensibility and low strength of cemented aeolian sand (AS)-fly ash (FA) backfill (CAFB) mixtures, CAFB was doped with fine coal gangue (CG) particles crushed to less than 4 mm and configured as cemented aeolian [...] Read more.
Aiming at the problems of large water secretion, poor suspensibility and low strength of cemented aeolian sand (AS)-fly ash (FA) backfill (CAFB) mixtures, CAFB was doped with fine coal gangue (CG) particles crushed to less than 4 mm and configured as cemented aeolian sand-coal gangue-fly ash backfill (CACFB) mixtures, in which coal gangue accounted for 8% of the mass ratio of the slurry. Through UCS and rheological experiments, using the response surface methodology and an orthogonal design, the following conclusions were drawn: (1) With the increase in ordinary Portland cement (PO) and slurry concentration, the UCS of the CACFB increased. (2) With the increase in the FA dosage, the UCS of the CACFB decreased first and then increased due to the gradual increase in FA dosage, destroying the reasonable ratio of the material and leading to the reduction in the material’s UCS, and with the growth in time, the volcanic ash effect of the FA caused the UCS of the material to increase. (3) With the increases in slurry concentration, the yield stress and viscosity coefficient of the slurry increased. (4) Reasonable proportions for CACFB should ensure the strength characteristics and rheological properties of the material. Through theoretical and experimental research, the final reasonable proportions were as follows: the concentrations of slurry, AS, CG, FA and PO were 77.5%, 42%, 8%, 17.5% and 10%, respectively. This ensured that the UCSs of the CACFB at 3 d, 7 d and 28 d were 1.2 MPa, 2.5 MPa and 4.3 MPa, respectively; the yield stress of the CACFB was 495 Pa, and the viscosity coefficient was 3.97 Pa·s. These reasonable proportions of the CACFB can meet the strength index and flow property of material industrial experiments. Full article
(This article belongs to the Special Issue Backfilling Materials for Underground Mining, Volume III)
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14 pages, 2183 KiB  
Article
Distribution of Uranium and Molybdenum in River Sediment near Molybdenite Mining Region: A Case Study in SW China
Minerals 2023, 13(11), 1435; https://doi.org/10.3390/min13111435 - 13 Nov 2023
Viewed by 648
Abstract
This work aims to understand the distribution and migration mechanisms of U and Mo between surface sediment and water in acid mine drainage (AMD) regions near a molybdenum mining region. A series of river sediment and water samples near the Jinduicheng mining area, [...] Read more.
This work aims to understand the distribution and migration mechanisms of U and Mo between surface sediment and water in acid mine drainage (AMD) regions near a molybdenum mining region. A series of river sediment and water samples near the Jinduicheng mining area, one of the largest deposits of molybdenite ore in Asia, were collected and analyzed. Our results indicate that: (1) The pH value of river water samples increases with distance from upstream to downstream, while the pH has poor correlation with Mo and U; (2) The content of Mo and U in the sediment are significantly higher than the background value, which suggests potential pollution; (3) The content of Mo and U in the water and sediments in the lower reaches of the Wenyu river is significantly linearly related with the distance from the mining area, suggesting that AMD is a potential source; (4) BCR analysis shows that Mo in river sediments mainly existed as the residual, while U mainly existed as the non-residual; (5) The distribution coefficient Kd(Mo) exceeds Kd(U), indicating that Mo is enriched in sediments while U is more prone to porewater. Full article
(This article belongs to the Section Mineral Geochemistry and Geochronology)
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18 pages, 7218 KiB  
Article
Vesicles and Reservoirs of Basic Lava Flows in the Laoheishan and Huoshaoshan Volcanoes, NE China
Minerals 2023, 13(11), 1434; https://doi.org/10.3390/min13111434 - 12 Nov 2023
Viewed by 692
Abstract
As an important part of the lava flow reservoir, vesicles affect reservoir performance to some extent. To explore the distribution, origins and importance of vesicles in different facies belts of basic lava flows. In this study, we selected representative field outcrops and samples [...] Read more.
As an important part of the lava flow reservoir, vesicles affect reservoir performance to some extent. To explore the distribution, origins and importance of vesicles in different facies belts of basic lava flows. In this study, we selected representative field outcrops and samples from different facies belts of the Laoheishan and Huoshaoshan lava flows in the Wudalianchi volcanics, Heilongjiang Province, identified and examined vesicles, measured their porosity and permeability, and analyzed their surface porosity. Three facies belts of vesicle shape, size, quantity, arrangement, origin, and connectivity between vesicles and fractures were identified. The results showed that the vesicles in the crater–near-crater belt were ellipsoidal and spherical, with many vesicles. The vesicles in the proximal belt were dominated by many ellipsoids with a uniform distribution. The vesicles in the distal belt were dominated by spherical and ellipsoidal vesicles, with a few tubular vesicles and a small number of vesicles. The findings suggest that the crater-near-crater belt and proximal belt have the best reservoir performance, whereas the distal belt has the worst. Full article
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17 pages, 6941 KiB  
Review
Progress in the Application of Biomimetic Mineralization for Tooth Repair
Minerals 2023, 13(11), 1433; https://doi.org/10.3390/min13111433 - 12 Nov 2023
Viewed by 1011
Abstract
The tooth, including enamel and dentin, is a prominent biomineral that is produced by the biomineralization of living organisms. Although the mechanical performance of the tooth is outstanding, caries easily develop in a complex oral environment. The analysis of the chemical composition and [...] Read more.
The tooth, including enamel and dentin, is a prominent biomineral that is produced by the biomineralization of living organisms. Although the mechanical performance of the tooth is outstanding, caries easily develop in a complex oral environment. The analysis of the chemical composition and the relationship between the mechanical properties and the structure is of great importance in solving caries. In this review, the multilevel structure and mechanical properties of enamel and dentin are briefly introduced, along with caries formation and the limitations of clinical dental restoration. Furthermore, the progress of the application of a wide range of biomimetic strategies for tooth remineralization is highlighted, including the use of calcium phosphate ionic clusters to construct the mineralization front, ensuring the oriented epitaxial growth of enamel crystals and replicating the complex structure of the enamel. Moreover, compared with the current clinical treatment, in which the resin composite and glass ionomer cement are the main repair materials and the high incidence of secondary caries leads to imperfect restorations, the remineralization tactics could achieve excellent repair effectiveness in reconstructing the complicated structure, restoring mechanical strength and gaining permanent repair. A basic understanding of enamel and dentin, their potential for restoration, and hopeful prospects for tooth repair that can be applied in the clinical setting, not just in the laboratory, is provided by this review. Full article
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26 pages, 41135 KiB  
Article
Predictive Mapping of Prospectivity for Gold in the Central Portion of the Tapajós Mineral Province, Brazil
Minerals 2023, 13(11), 1432; https://doi.org/10.3390/min13111432 - 12 Nov 2023
Viewed by 997
Abstract
This work aims to model mineral prospectivity for intrusion–related gold deposits in the central portion of the Tapajós Mineral Province (TMP), southwestern Pará state. The scope includes experimentation and evaluation of knowledge and data-driven methods applied to multisource data to predict potential targets [...] Read more.
This work aims to model mineral prospectivity for intrusion–related gold deposits in the central portion of the Tapajós Mineral Province (TMP), southwestern Pará state. The scope includes experimentation and evaluation of knowledge and data-driven methods applied to multisource data to predict potential targets for gold mineralization. The radiometric data processing allowed to identify a hydrothermal alteration footprint of known gold deposits, providing information in regions with little or no field data available. The aeromagnetic data analysis prompted the identification of high magnetic zones, which are probably related to hydrothermal fluid transport. Linear features extracted from digital elevation data revealed an NNW–SSE general trend, which is consistent with the main structural control of deposits. The data were integrated through three modeling techniques—fuzzy logic (knowledge-driven), weights of evidence (WofE, data-driven), and a machine learning algorithm (SVM, data-driven)—resulting in three prospective models. In all models, the majority of indicated prospective regions coincide with the known deposits. The results obtained in the models were combined to generate an agreement map, which mapped the overlapping of their highest prospective scores, indicating new areas of prospective interest in the central portion of the TMP. Full article
(This article belongs to the Special Issue Footprints of Mineral Systems)
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