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Minerals, Volume 14, Issue 11 (November 2024) – 124 articles

Cover Story (view full-size image): The growth of gypsum crystals by anhydrite dissolution contributes to forming some of the most spectacular natural mineral exhibits, such as the large gypsum crystals in the giant geode of Pulpí (Almeria, Spain), as depicted in our cover picture. Beyond their beauty, these gypsum crystals present a scientific challenge for crystal growers and mineralogists. In this study, we demonstrate that the growth of gypsum by anhydrite dissolution can be replicated within a laboratory timescale, mimicking the natural geochemical environment. We monitor anhydrite's dissolution and gypsum crystal growth in situ under oscillatory temperatures using a customized experimental setup and time-lapse optical microscopy. We also discuss how our findings with the geological history of Pulpì mineralization. View this paper
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24 pages, 5939 KiB  
Article
Bismuth Sulfosalts from the Nistru Metallogenetic Field, Baia Mare Zone, NW Romania
by Floarea Damian, Gheorghe Damian, Nigel J. Cook, Vsevolod Yu. Prokofiev and Peter András
Minerals 2024, 14(11), 1182; https://doi.org/10.3390/min14111182 - 20 Nov 2024
Viewed by 520
Abstract
An association of bismuth sulfosalts coexisting with native gold is described from a sulfide-rich copper vein in the Nistru area, Baia Mare metallogenetic district, NW Romania. This mineralization is hosted within a Neogene calc-alkaline subvolcanic porphyry quartz-micromonzodiorite stock on the southern border of [...] Read more.
An association of bismuth sulfosalts coexisting with native gold is described from a sulfide-rich copper vein in the Nistru area, Baia Mare metallogenetic district, NW Romania. This mineralization is hosted within a Neogene calc-alkaline subvolcanic porphyry quartz-micromonzodiorite stock on the southern border of the Gutâi Mountains. Cu+Au+Bi mineralization represents the inner part of a zoned vein of a type specific to the SE part of the Nistru orefield. The Pb-Zn and Au-Ag veins are located towards the external zone at the boundary of the stock with the surrounding rocks. Bismuth sulfosalts are mainly represented by bismuthinite derivatives and members of the lillianite homologous series. Cosalite, matildite and wittichenite are also present in subordinate amounts. Bi-rich members of the bismuthinite-aikinite series (from krupkaite to bismuthinite) are predominant. A phase with the empirical formula CuPbBi7S12 was also identified and could potentially be a new bismuthinite derivative. The lillianite homologous series is represented by phases with composition between Gus73 and Gus59, with a dominance of members closer to gustavite (Gus97–79) and less abundant members closer to lillianite (Gus49). Native gold and Bi-sulfosalts are closely associated with the main sulfides (pyrrhotite, pyrite, chalcopyrite) and quartz, indicating simultaneous crystallization. Fluid inclusion data for quartz indicate a temperature interval between 205 and 247 °C. The assemblage within this vein was deposited from a low-salinity fluid (0.4–2.6 wt.% NaCl equiv.) and density from 0.80 to 0.87 g/cm3. Full article
(This article belongs to the Section Mineral Deposits)
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12 pages, 2138 KiB  
Communication
First Optically Stimulated Luminescence and Radiocarbon Dating of the Late Quaternary Eruptions in the Xilinhot Volcanic Field, China
by Zhiwei Shi, Furong Cui, Zhidan Zhao, Zhida Bai, Zeguang Chang and Junxiang Zhao
Minerals 2024, 14(11), 1181; https://doi.org/10.3390/min14111181 - 20 Nov 2024
Viewed by 495
Abstract
Precise dating of prehistoric volcanic eruptions is essential for reconstructing eruption sequences and assessing volcanic hazards. The timing of the onset and termination of volcanic activity in the Xilinhot volcanic field (XVF) has been a topic of debate for years. Volcanic eruptions in [...] Read more.
Precise dating of prehistoric volcanic eruptions is essential for reconstructing eruption sequences and assessing volcanic hazards. The timing of the onset and termination of volcanic activity in the Xilinhot volcanic field (XVF) has been a topic of debate for years. Volcanic eruptions in this area began during the Pliocene, with the K-Ar (Ar-Ar) method providing reliable ages for early formed volcanic rocks; however, this method is less effective for dating younger volcanic events that occurred since the Late Pleistocene. For younger volcanoes, sediments baked by volcanic materials, organic sediments, and silty mudstones entrapped in lava serve as excellent geological carriers for dating. In this study, suitable samples collected from the XVF were dated using 14C and optically stimulated luminescence (OSL) methods. The 14C ages obtained for the Gezishan volcano are ~6.8 cal. ka BP, while its OSL age is ~7.8 ka. The ages dated by these two methods, combined with volcano–sedimentary stratigraphic relationships and volcanic topography, confirm the Holocene eruptions of the Gezishan volcano, categorizing it as a broadly active volcano. The upper boundary age of the sandy loam layer beneath the Gezishan lava flow is ~15.5 ka, indicating that the south lava of the Gezishan effusion occurred later than the late stage of the Late Pleistocene. Additionally, the OSL ages of baked sediments at the bottom of the base surge deposits from a Maar-type volcano and aeolian sand interlayers within a Strombolian-type scoria cone in the study area are ~50 ka and ~60 ka, respectively, representing eruptions in the middle Late Pleistocene. These findings demonstrate that volcanic activity in the XVF remained vigorous during the Late Pleistocene to Holocene. This study provides significant insights for reconstructing the evolutionary history of Xilinhot volcanic activity and assessing regional volcanic hazards. Full article
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20 pages, 4203 KiB  
Article
Impact of Inline Polyacrylamide Polymer Flocculation on the Mechanical and Hydrological Properties of Saline Tailings
by Bob Boshrouyeh, Mansour Edraki, Thomas Baumgartl, Allan Costine, Sebastian Quintero Olaya, Kateřina Lepková and Deepak Dwivedi
Minerals 2024, 14(11), 1180; https://doi.org/10.3390/min14111180 - 20 Nov 2024
Viewed by 422
Abstract
This study examines the geotechnical and hydro-mechanical behaviour of a model slurry used in high-solids, high-salinity applications, both before and after inline flocculation with an anionic polyacrylamide. Initial evaluations showed untreated tailings (UT) with a water content of 107%, void ratio of 2.6, [...] Read more.
This study examines the geotechnical and hydro-mechanical behaviour of a model slurry used in high-solids, high-salinity applications, both before and after inline flocculation with an anionic polyacrylamide. Initial evaluations showed untreated tailings (UT) with a water content of 107%, void ratio of 2.6, and dry density of 0.711 t/m3, compared to polymer-amended tailings (PAT) with 53% water content, a void ratio of 1.6, and a dry density of 1.069 t/m3. Post-flocculation consolidometer tests revealed a distinct consolidation mode, with PAT showing 60% less settlement within the first 48 h and achieving 50% more free water drainage. Polymer treatment improved consolidation parameters, yielding a lower compressibility index (Cc of 0.74 vs. 1.05 for raw slurry), a higher coefficient of consolidation (Cv of 0.005 cm2/s for PAT vs. 0.0009 cm2/s for raw slurry), and an increased water retention capacity. Additionally, PAT demonstrated a final void ratio of 0.62 compared to 0.51 for the UT sample and an internal porosity characterised by discrete voids, supporting enhanced stability for long-term rehabilitation. These findings underscore the potential of inline flocculation to improve tailings management in saline conditions. Full article
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18 pages, 3743 KiB  
Article
Efficient Reuse of Rare Earth Carbonate Precipitation Mother Liquor for Rare Earth Leaching in Strong Acid-Restricted Area
by Jian Feng, Xiaoyan Wu, Fang Zhou and Ruan Chi
Minerals 2024, 14(11), 1179; https://doi.org/10.3390/min14111179 - 20 Nov 2024
Viewed by 403
Abstract
Due to the restrictions of strong acids in some regions, the reuse process of rare earth (RE) precipitation mother liquor is difficult to carry out. To achieve the straightforward and efficient reuse of precipitation mother liquor in such areas, the potential for directly [...] Read more.
Due to the restrictions of strong acids in some regions, the reuse process of rare earth (RE) precipitation mother liquor is difficult to carry out. To achieve the straightforward and efficient reuse of precipitation mother liquor in such areas, the potential for directly reusing this liquor for rare earth (RE) leaching was explored. The results showed that when the RE concentration in the leachate ranged from 0.1 to 1.5 g/dm3 and the RE precipitation rate exceeded 96%, the residual total carbonate content in precipitation mother liquor was less than 0.01 mol/L, and the solution pH was 7–8. Furthermore, when the total carbonate content in leaching liquor was lower than 0.01 mol/L, the presence of carbonate had a minimal impact on the RE leaching efficiency, which was observed to exceed 93%. Additionally, the process of mother liquor leaching was analyzed using dynamic models and chromatography tray theory. It was found that the leaching results were well fitted with the shrinking core model, and the apparent activation energy of RE was 5.77 kJ/mol, indicating that the reaction was controlled by diffusion, and the reaction order was 0.672 for RE. This confirms that a total carbonate content below 0.01 mol/L in the precipitation mother liquor can be directly used for the RE leaching process. Full article
(This article belongs to the Special Issue Green and Efficient Recovery/Extraction of Rare Earth Resources)
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18 pages, 8943 KiB  
Article
Micro-Topographic Controls on Rare Earth Element Accumulation and Fractionation in Weathering Profiles: Case Study of Ion-Adsorption Rare Earth Element Deposit in Hedi, Zhejiang Province, China
by Wenlin Guo, Zhi Zhao, Chengshan Wang, Denghong Wang, Xiaorong Chen, Xiaoliang Dang, Wei Zhang and Chenhui Zhao
Minerals 2024, 14(11), 1178; https://doi.org/10.3390/min14111178 - 20 Nov 2024
Viewed by 451
Abstract
Ion-adsorption rare earth element (REE) deposits are a major source of REEs and are found mainly in China. The formation of such deposits is affected by a combination of endogenic and exogenic factors. This study investigated the effect of micro-topography on the REE [...] Read more.
Ion-adsorption rare earth element (REE) deposits are a major source of REEs and are found mainly in China. The formation of such deposits is affected by a combination of endogenic and exogenic factors. This study investigated the effect of micro-topography on the REE distribution in four weathering profiles at different topographic sites on a knoll in Hedi, Zhejiang Province, China. The weathering profile and REE accumulation are both most developed at mid-slope positions of the knoll. The intensity of chemical weathering decreases in the order of mid-slope > base > summit. As weathering progressed, REE enrichment initially increased but later decreased, with a progressive increase in light/heavy REE fractionation. REE fractionation is more pronounced on the north-facing slope than on the south-facing slope. Weathering degrees and clay mineral characteristics are key factors influencing the varying REE distributions on the knoll. Water leaching and the evolution of clay minerals towards higher maturity reduce REE adsorption capacity. Clay minerals also play a significant role in REE fractionation; the abundance of these minerals and the presence of illite enable the retention of more HREEs with minimal desorption. Taking into account water content, it is inferred that hydrological conditions, modulated by the micro-topography, strongly affect the depth and extent of REE accumulation, as well as fractionation. Full article
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19 pages, 4109 KiB  
Article
Preliminary Beneficiation Studies of Quartz Samples from the Northwest Territories, Canada
by Hanyu Zhang, Gideon Lambiv Dzemua and Qi Liu
Minerals 2024, 14(11), 1177; https://doi.org/10.3390/min14111177 - 20 Nov 2024
Viewed by 436
Abstract
Three quartz-rich geologic materials—vein quartz from the Great Bear Magmatic Zone, massive quartz from the Nechalacho rare earth deposit, and quartz sands from the Chedabucto silica sand deposit along the shores of the Northern Arm of the Great Slave Lake, Northwest Territories of [...] Read more.
Three quartz-rich geologic materials—vein quartz from the Great Bear Magmatic Zone, massive quartz from the Nechalacho rare earth deposit, and quartz sands from the Chedabucto silica sand deposit along the shores of the Northern Arm of the Great Slave Lake, Northwest Territories of Canada—were evaluated for their amenability to physical beneficiation into high-purity quartz (HPQ). The samples were subjected to various treatment processes, including crushing, grinding, calcining and quenching, acid leaching, wet high-intensity magnetic separation (WHIMS), and reverse flotation. After treatment, both the core and sand quartz samples met the requirements for HPQ, making them suitable for use in the production of semiconductor filters, liquid crystal displays (LCDs), and optical glass. However, the Al-bearing impurity content in the vein quartz products remained relatively high, and most of these impurities were dispersed in the quartz lattice, requiring further processing to meet the purity standards for HPQ required by these industries. Full article
(This article belongs to the Special Issue Physicochemical Properties and Purification of Quartz Minerals)
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23 pages, 5951 KiB  
Article
The Core Story: Intertwined Maternal and Progeny Signatures Enclosed in the Otolith
by Clara Anne Lord, Sophie Berland, Vincent Haÿ and Philippe Keith
Minerals 2024, 14(11), 1176; https://doi.org/10.3390/min14111176 - 20 Nov 2024
Viewed by 442
Abstract
Analytical imaging via synchrotron analysis was used to study sagittal otoliths of four freshwater pipefish species exhibiting amphidromous or freshwater resident lifestyles. We undertook a hyperfine elemental scanning of a 25 μm diameter length area centred on the core, namely the pre-hatch zone, [...] Read more.
Analytical imaging via synchrotron analysis was used to study sagittal otoliths of four freshwater pipefish species exhibiting amphidromous or freshwater resident lifestyles. We undertook a hyperfine elemental scanning of a 25 μm diameter length area centred on the core, namely the pre-hatch zone, corresponding to the sagitta formed during embryogenesis. We analysed calcium (Ca), strontium (Sr), manganese (Mn), chromium (Cr), cobalt (Co), nickel (Ni) and sulphur (S), with the latter serving to count growth increments. Whatever the species, a Ca pit consistently marked the core; the amphidromous species exhibited Mn enrichment at the core and the sagitta formed a week before hatching. These results illustrate common otolith formation mechanistic processes. Sr and heavy metals’ signals in the pre-hatch zone were compared to their signal in the edge of the otolith, an area encompassing the adult freshwater (adFW) environmental signature. We found that Co and Ni otolith signals had no relation to environmental conditions, but it is worth looking into Cr as a marker of early-life environment. While we caution against the use of a Sr:Ca ratio for life history interpretations at the core because of the Ca pit, the Sr signal analysis uncovered possible variations in the parental behaviour that potentially trigger newly-hatched juvenile migration to sea or residency. Finally, our results demonstrate that the microchemistry of otolith formation during early development is a melting of maternal signal during egg yolk elaboration, of the environmental signal during egg incubation, and of individual physiology during early growth. Full article
(This article belongs to the Section Biomineralization and Biominerals)
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20 pages, 2991 KiB  
Article
Gypsum: From the Equilibrium to the Growth Shapes—Theory and Experiments
by Dino Aquilano, Marco Bruno and Stefano Ghignone
Minerals 2024, 14(11), 1175; https://doi.org/10.3390/min14111175 - 19 Nov 2024
Viewed by 510
Abstract
The gypsum crystals (CaSO4·2H2O) crystallizes in a low symmetry system (monoclinic) and shows a marked layered structure along with a perfect cleavage parallel to the {010} faces. Owing to its widespread occurrence, as a single or twinned crystal, here [...] Read more.
The gypsum crystals (CaSO4·2H2O) crystallizes in a low symmetry system (monoclinic) and shows a marked layered structure along with a perfect cleavage parallel to the {010} faces. Owing to its widespread occurrence, as a single or twinned crystal, here the gypsum equilibrium (E.S.) and growth shapes (G.S.) have been re-visited. In making the distinction among E.S. and G.S., in the present work, the basic difference between epitaxy and homo-taxy is clearly evidenced. Gypsum has also been a fruitful occasion to recollect the general rules concerning either contact or penetration twins, for free growing and for twinned crystals nucleating onto pre-existing substrates. Both geometric and crystal growth aspects have been considered as well, by unifying theory and experiments of crystallography and crystal growth through the intervention of βadh, the physical quantity representing the specific adhesion energy between gypsum and other phases. Hence, the adhesion energy allowed us to systematically use the Dupré’s formula. In the final part of the paper, peculiar attention has been paid to sediments (or solution growth) where the crystal size is very small, in order to offer a new simple way to afford classical (CNT) and non-classical nucleation (NCNT) theories, both ruling two quantities commonly used in the industrial crystallization: the total induction times (tindtotal) and crystal size distribution (CSD). Full article
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20 pages, 12316 KiB  
Article
Effect of Selective Milling on the Concentration Process of Critical Raw Materials from MSW Incinerator Bottom Ash
by Ida B. G. S. Adhiwiguna, S. Humaira Sahbudin, Winfried Ruhkamp, Ragnar Warnecke and Rüdiger Deike
Minerals 2024, 14(11), 1174; https://doi.org/10.3390/min14111174 - 19 Nov 2024
Viewed by 569
Abstract
This research introduces selective milling as a reliable and effective initial concentration process to enable efficient separation and ensure high recovery rates of valuable and critical materials (minerals and metals) from processed incinerator bottom ash (pr.IBA), a treated mineral fraction originating from the [...] Read more.
This research introduces selective milling as a reliable and effective initial concentration process to enable efficient separation and ensure high recovery rates of valuable and critical materials (minerals and metals) from processed incinerator bottom ash (pr.IBA), a treated mineral fraction originating from the conventional municipal solid waste (MSW) incinerator bottom ash (IBA) processing steps. Four different types of pr.IBA (each sample weighing up to three tons) were selectively milled using a demonstration-scale vertical roller mill to produce three distinct products: fine, middle, and coarse fractions. Chemical analysis demonstrated that a concentration step after selective milling could be reliably achieved regardless of the variation in the sources and qualities of the input materials. Specifically, calcium-containing compounds can be enriched in the fine fraction, potentially containing Ca2SiO4, CaSO4, and CaCO3. Complementary to its particle size equivalent to the raw mix, this calcium segregation could be valuable as an alternative material in cement clinker production. Conversely, the segregation of metal-bearing substances, particularly iron and copper, was detected in the coarse fraction. Such segregation is comparable to specific ore grades and enhances the possibility of metal recovery from pr.IBA. Full article
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24 pages, 10810 KiB  
Article
Petrogenesis of the Shibaogou Mo-W-Associated Porphyritic Granite, West Henan, China: Constrains from Geochemistry, Zircon U-Pb Chronology, and Sr-Nd-Pb Isotopes
by Zhiwei Qiu, Zhenju Zhou, Nan Qi, Pocheng Huang, Junming Yao, Yantao Feng and Yanjing Chen
Minerals 2024, 14(11), 1173; https://doi.org/10.3390/min14111173 - 19 Nov 2024
Viewed by 452
Abstract
The Shibaogou pluton, located in the Luanchuan orefield of western Henan Province in China, is a typical porphyritic granite within the Yanshanian “Dabie-type” Mo metallogenic system. It is mainly composed of porphyritic monzogranite and porphyritic syenogranite. Zircon U-Pb dating results indicate emplacement ages [...] Read more.
The Shibaogou pluton, located in the Luanchuan orefield of western Henan Province in China, is a typical porphyritic granite within the Yanshanian “Dabie-type” Mo metallogenic system. It is mainly composed of porphyritic monzogranite and porphyritic syenogranite. Zircon U-Pb dating results indicate emplacement ages of 150.1 ± 1.3 Ma and 151.0 ± 1.1 Ma for the monzogranite and 148.1 ± 1.0 Ma and 148.5 ± 1.3 Ma for the syenogranite. The pluton is characterized by geochemical features of high silicon, metaluminous, and high-K calc-alkaline compositions, enriched in Rb, U, Th, and Pb, and exhibits high Sr/Y (18.53–58.82), high (La/Yb)N (9.01–35.51), and weak Eu anomalies. These features indicate a source region from a thickened lower crust with garnet and rutile as residual phases at depths of approximately 40–60 km. Sr-Nd-Pb isotopic analyses suggest that the magmatic source is mainly derived from the Taihua and Xiong’er Groups of the Huaxiong Block, mixed with juvenile crustal rocks from the Kuanping and Erlangping Groups of the North Qinling Accretion Belt. Combined with geological and isotopic characteristics, it is concluded that the Shibaogou pluton formed during the compression–extension transition period associated with the collision between the Yangtze Block and the North China Craton, reflecting the complex partial melting processes in the thickened lower crust. The present study reveals that the magmatic–hydrothermal activity at Shibaogou lasted approximately 5 Ma, showing multi-phase characteristics, further demonstrating the close relationship between the pluton and the Mo-W mineralization. Full article
(This article belongs to the Section Mineral Geochemistry and Geochronology)
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26 pages, 9981 KiB  
Article
Ore Formation and Mineralogy of the Alattu–Päkylä Gold Occurrence, Ladoga Karelia, Russia
by Vasily I. Ivashchenko
Minerals 2024, 14(11), 1172; https://doi.org/10.3390/min14111172 - 18 Nov 2024
Viewed by 539
Abstract
The Alattu–Päkylä gold occurrence is located in the Northern Lake Ladoga area, in the Raaha-Ladoga suprasubduction zone, at the Karelian Craton (AR)—Svecofennian foldbelt (PR1) boundary. Its gold ore mineral associations are of two types of mineralization: (1) copper–molybdenum–porphyry with arsenopyrite and [...] Read more.
The Alattu–Päkylä gold occurrence is located in the Northern Lake Ladoga area, in the Raaha-Ladoga suprasubduction zone, at the Karelian Craton (AR)—Svecofennian foldbelt (PR1) boundary. Its gold ore mineral associations are of two types of mineralization: (1) copper–molybdenum–porphyry with arsenopyrite and gold (intrusion-related) and (2) gold–arsenopyrite–sulfide in shear zones. Optical and scanning electron microscopy, X-ray fluorescence spectrometry, inductively coupled plasma mass spectrometry (ICP-MS), instrumental neutron activation analysis (INAA) and fire analysis with AAS finishing were used to study them. Type 1 was provoked by shallow-depth tonalite intrusion (~1.89 Ga) and type 2 by two stages of Svecofennian metamorphism (1.89–1.86 and 1.83–1.79 Ga) with the possible influence of the impactogenesis of the Janisjärvi astrobleme (age ~1 Ga). Intrusive and host rocks were subjected to shearing accompanied by the formation of ore-bearing metasomatic rocks of the propylite-beresite series (depending on substrate) and quartz–sericite, quartz and sericite–tourmaline veins and streaks. Ore mineralization is present as several consecutive mineral associations: pyritic–molybdenite with arsenopyrite and gold; gold–arsenopyrite; quartz–arsenopyrite with antimony sulfosalts of lead; gold–polysulfide with tetrahedrite –argentotetrahedrite series minerals and gold–antimony with Pb–Sb–S system minerals and native antimony. Arsenopyrite contains invisible (up to 234 ppm) and visible gold. Metamorphosed domains in arsenopyrite and rims with visible gold around it are usually enriched in As, indicating higher (up to >500 °C) temperatures of formations than original arsenopyrite with invisible gold (<500 °C). A paragenetic sequence associated with the deposition of invisible and visible gold established at the Alattu–Päkylä ore occurrence: pyrrhotite + unaltered arsenopyrite (with invisible gold) → altered arsenopyrite (As-enriched) + pyrite ± pyrrhotite + visible gold. Gold, associated with gudmundite, sphalerite and native antimony, seems to be due to cainotypic rhyodacitic porphyry cutting tonalite intrusion or with a retrograde stage in post-Svecofennian metamorphism. The isotopic composition of Pb and 238U/204Pb (9.4–9.75) for the feldspar of the tonalite intrusion and the pyrite of gold mineralization, εNd (−4 up to −5) for tonalites and ẟ34S values of −2.10–+4.99 for arsenopyrite, indicate the formation of gold occurrence provoked by Svecofennian magmatic and tectono-thermal processes with the involvement of matter from a mantle-lower crustal reservoir into magma formation and mineralization. Full article
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18 pages, 7145 KiB  
Review
Evolution of Auriferous Fluids in the Kraaipan-Amalia Greenstone Belts: Evidence from Mineralogical and Isotopic Constraints
by Kofi Adomako-Ansah, Napoleon Q. Hammond, Yuichi Morishita and Daizo Ishiyama
Minerals 2024, 14(11), 1171; https://doi.org/10.3390/min14111171 - 18 Nov 2024
Viewed by 506
Abstract
The Kraaipan and Amalia greenstone belts in South Africa occur in the western part of the Kaapvaal Craton. The two belts stretch discontinuously in an approximately north–south orientation over a distance of about 250 km from southern Botswana in the north to the [...] Read more.
The Kraaipan and Amalia greenstone belts in South Africa occur in the western part of the Kaapvaal Craton. The two belts stretch discontinuously in an approximately north–south orientation over a distance of about 250 km from southern Botswana in the north to the Vaal River near Christiana in the south and are separated by a distance of about 90 km. Gold mineralization is hosted in banded iron formation at both the Kalahari Goldridge deposit (Kalgold) in the Kraaipan greenstone belt in the north and the Amalia deposit in the Amalia greenstone belt in the south, with the mineralization associated with quartz–carbonate veins. The footwalls of these deposits are generally composed of mafic volcanic schist and the hanging walls consisting of graywackes, schist and shale units. The Kalgold and Amalia gold deposits show some variation in the redox condition of the mineralizing system and fluid chemistry. The ore mineral assemblage is characterized by magnetite–pyrrhotite–pyrite at Kalgold, which is indicative of reducing conditions, and a magnetite–hematite–pyrite assemblage at Amalia that suggests a relatively oxidizing environment. Average mineralizing temperatures determined from chlorite geothermometry were relatively higher at the Kalahari Goldridge deposit ranging from 350 to 400 °C compared to the slightly cooler range of 330 to 390 °C at Amalia. The composition of the fluids derived from fluid inclusions is indicative of low salinity H2O--CO2±CH4-rich fluids at Kalgold against relatively H2O-CO2-rich fluids at Amalia. Evidence from strontium–carbon–oxygen isotopic ratios from carbonates suggests that differences in redox conditions in the deposits could be attributed to different flow pathways by an evolving fluid from a common source (with minimum 87Sr/86Sr = 0.70354) to the sites of gold deposition, with a significant ore fluid interaction with a thick sequence of carbonaceous meta-pelitic rock units at the Kalahari Goldridge deposit that is absent in the Amalia deposit. Full article
(This article belongs to the Special Issue Geochemistry and Genesis of Hydrothermal Ore Deposits)
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21 pages, 15199 KiB  
Article
Tracking Depositional Architecture and Diagenetic Evolution in the Jurassic Carbonates, Trans Indus Ranges, NW Himalayas
by Muhammad Jamil, Ihsan Ullah, Hamad Ur Rahim, Imran Khan, Wahid Abbas, Mohib Ur Rehman, Alidu Rashid, Muhammad Umar, Asad Ali and Numair Ahmed Siddiqui
Minerals 2024, 14(11), 1170; https://doi.org/10.3390/min14111170 - 18 Nov 2024
Viewed by 609
Abstract
The evolution of Jurassic carbonates is globally significant for understanding the depositional framework, diagenetic phases and sedimentary characteristics of shallow marine shelf deposits. For this purpose, two outcrop sections of the Jurassic carbonates with a road distance of 121 km in the Trans [...] Read more.
The evolution of Jurassic carbonates is globally significant for understanding the depositional framework, diagenetic phases and sedimentary characteristics of shallow marine shelf deposits. For this purpose, two outcrop sections of the Jurassic carbonates with a road distance of 121 km in the Trans Indus Ranges, NW Himalayas, were included in this study. Geological fieldwork was conducted for sedimentological data, and representative samples were collected for microfacies analysis and diagenetic evolution complemented by carbon and oxygen isotope analysis. Results show that eight microfacies were identified in both sections where mudstone microfacies was only present in the Chichali section, whereas wackestone and packstone facies widely existed in both sections. The diagenetic evolution interpreted that dolomitization and stylolization were pronounced in the Paniala section, while micritization and calcite cementation were prevalent in the Chichali section. The interpreted depositional setting implies the wide range from supratidal to outer ramp shallow marine for the Chichali section, suggesting a wide range and relatively deeper environment, alongside merely intertidal to middle ramp settings for Paniala section. Diagenetic evolution suggests marine to meteoric influence in the Chichali section, while burial and uplift phases were dominant in the Paniala section. The diagenetic events were also validated by the isotopic analysis, where most of the samples with values up to −4‰ VPDB δ18O, corresponding to a carbon isotope range of up to +4‰, were interpreted as the burial phase of diagenesis; meanwhile, a few samples with −2 δ13C and −7‰ VPDB δ18O isotope signatures were marked as meteoric influx in the Paniala section. This study indicates the diversity of the depositional environment and diagenetic heterogeneity by integration of thin sections using isotope data, which are quite applicable to shallow marine carbonates. Full article
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19 pages, 6058 KiB  
Article
Influence of Precursor Particle Size and Calcium Hydroxide Content on the Development of Clay Brick Waste-Based Geopolymers
by Ronaldo A. Medeiros-Junior, Marisa Thiesen, Andrea Murillo Betioli, Juliana Machado Casali, Luiz Fernando Zambiasi Trentin, Andreza Frare and Allan Guimarães Borçato
Minerals 2024, 14(11), 1169; https://doi.org/10.3390/min14111169 - 18 Nov 2024
Viewed by 563
Abstract
This study evaluated the effect of precursor particle size and calcium hydroxide (CH) incorporation on the microstructure, compressive strength, and rheological properties of clay brick waste (BW)-based geopolymers. Rheological analyses were used to evaluate the fresh state of the geopolymers. XRD, SEM, and [...] Read more.
This study evaluated the effect of precursor particle size and calcium hydroxide (CH) incorporation on the microstructure, compressive strength, and rheological properties of clay brick waste (BW)-based geopolymers. Rheological analyses were used to evaluate the fresh state of the geopolymers. XRD, SEM, and EDS analyses were performed to analyze the microstructure. The results showed that the particle size reduction in BW and the incorporation of CH significantly contributed to obtaining better compressive strength in the geopolymers. Furthermore, the particle size reduction decreased the yield stress, plastic viscosity, and hysteresis area of the geopolymers, while the incorporation of CH promoted the opposite effect. Increasing the CH incorporation content accelerated the geopolymerization reactions and reduced the workability of the geopolymers over time. However, since the milling process is costly, milling BW for 2 h was more efficient from a technical–economic point of view. In addition, the incorporation of CH not only promoted the early hardening of the geopolymers when necessary, but also contributed to the improvement of the compressive strength through matrix densification. Therefore, the results of this study show the definition of more efficient material proportions for geopolymers using waste as an aluminosilicate source. Full article
(This article belongs to the Special Issue Alkali Activation of Clay-Based Materials)
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12 pages, 2998 KiB  
Article
DFT Study on the Interaction Between Flotation Agents and Lepidolite-1M Surfaces
by Xujun Zhang, Guichun He and Changzhen Du
Minerals 2024, 14(11), 1168; https://doi.org/10.3390/min14111168 - 18 Nov 2024
Viewed by 473
Abstract
The surface chemical properties of Lepidolite-1M crystals are closely related to their flotation properties. This paper uses density functional theory (DFT) to analyze the band structure, population, and state density of ideal Lepidolite-1M crystals. The results show that lepidolite-1M is an insulator, and [...] Read more.
The surface chemical properties of Lepidolite-1M crystals are closely related to their flotation properties. This paper uses density functional theory (DFT) to analyze the band structure, population, and state density of ideal Lepidolite-1M crystals. The results show that lepidolite-1M is an insulator, and its most probable positively charged active site is Al, and its negatively charged active sites are O and F. To further investigate the adsorption mechanism of Lepidolite-1M during comminution and flotation processes, we calculated the surface energy, population, state density, and differential charge density of its most common (001) surface. The results show that its surface energy is 0.9934 J/m2, occurred in the valence electron configurations, population values, and bond lengths of the surface atoms. Furthermore, oxygen atoms on the (001) surface showed different activities, with F and O atoms in the lithium-rich region showing significant electron enrichment. Overall, our results demonstrated that anion collectors react mainly with the Al sites on the surface of Lepidolite-1M, and the cationic collectors and metal ion activators can be adsorbed on the surface of Lepidolite-1M to produce better trapping and activation capabilities. Full article
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27 pages, 6065 KiB  
Article
Extraction of Lanthanides(III) from Nitric Acid Solutions with N,N′-dimethyl-N,N′-dicyclohexyldiglycolamide into Bis(trifluoromethylsulfonyl)imide-Based Ionic Liquids and Their Mixtures with Molecular Organic Diluents
by Alexander N. Turanov, Vasilii K. Karandashev, Vladimir E. Baulin, Yury M. Shulga and Dmitriy V. Baulin
Minerals 2024, 14(11), 1167; https://doi.org/10.3390/min14111167 - 17 Nov 2024
Viewed by 587
Abstract
The extraction of lanthanides(III) from aqueous nitric acid solutions with novel unsymmetrical diglycolamide extactant, N,N′-dimethyl-N,N′-dicyclohexyldiglycolamide (DMDCHDGA) into bis(trifluoromethylsulfoyl)imide-based ionic liquids (ILs), namely 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C4mim][Tf2N]), 1-octyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C8mim][Tf2N]), benzyltriethylammonium bis(trifluoromethylsulfonyl)imide ([N222Bn][Tf2N]) [...] Read more.
The extraction of lanthanides(III) from aqueous nitric acid solutions with novel unsymmetrical diglycolamide extactant, N,N′-dimethyl-N,N′-dicyclohexyldiglycolamide (DMDCHDGA) into bis(trifluoromethylsulfoyl)imide-based ionic liquids (ILs), namely 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C4mim][Tf2N]), 1-octyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C8mim][Tf2N]), benzyltriethylammonium bis(trifluoromethylsulfonyl)imide ([N222Bn][Tf2N]) methyltrioctylammonium bis(trifluoromethylsulfonyl)imide ([N1888][Tf2N]), and their mixtures with molecular organic diluent 1,2-dichloroethane (DCE), is studied. DMDCHDGA has been shown to interact with components of the IL [C4mim][Tf2N]. The effect of HNO3 concentration in the aqueous phase on the extraction of Ln(III) ions is studied. The stoichiometry of the extracted complexes is determined, and the mechanism of Ln(III) extraction in a system with [C4mim][Tf2N] is discussed. It is shown that the efficiency and intragroup selectivity of the extraction of Ln(III) ions with DMDCHDGA into [C4mim][Tf2N] is significantly higher than when using its symmetric analog TODGA. Full article
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24 pages, 27545 KiB  
Article
Superimposed Mineralization in the Xiaorequanzi Cu Deposit, Xinjiang: Evidence from Fluid Inclusions, H-O-S Isotopes, and Pyrite Trace Elements
by Yongqi Hao, Shunda Li, Fang Xia, Chuan Chen, Lingling Gao, Wei Wang, Xiaofei Du and Chenmeng Li
Minerals 2024, 14(11), 1166; https://doi.org/10.3390/min14111166 - 17 Nov 2024
Viewed by 503
Abstract
The Xiaorequanzi Cu deposit is located in the western part of the Dananhu–Tousuquan Island arc in eastern Tianshan, Xinjiang. It includes stratiform and epithermal-related veinlet mineralization. However, the genesis of this deposit remains controversial. Therefore, fluid inclusions, H–O isotopes, in situ S, and [...] Read more.
The Xiaorequanzi Cu deposit is located in the western part of the Dananhu–Tousuquan Island arc in eastern Tianshan, Xinjiang. It includes stratiform and epithermal-related veinlet mineralization. However, the genesis of this deposit remains controversial. Therefore, fluid inclusions, H–O isotopes, in situ S, and trace elements in pyrite were employed in this study to constrain the origins of the deposit. The Xiaorequanzi Cu deposit’s mineralization stages can be categorized into the following three phases: I. volcanogenic massive sulfide (VMS) mineralization; II. quartz–chalcopyrite–pyrite; and III. quartz–chalcopyrite–sphalerite stages. Fluid inclusion studies suggest that Stage I is distinguished by high-temperature (peak: 320–360 °C) and moderate-salinity (peak: 7–9 wt%) fluids belonging to the H2O–NaCl ± CO2 system. Stages II–III only exhibit vapor–liquid inclusions, with mineralizing fluids belonging to the medium-to-low-temperature (Stage II peak: 160–180 °C; Stage III peak: 120–130 °C) and medium-to-low-salinity (Stage II peak: 5–7 wt%; Atage III peak: 4–6 wt%) H2O–NaCl system. The H–O isotopic data suggest that mineralizing fluid in Stage I is a blend of magmatic and paleo-seawater sources, while in Stages II–III, meteoric water predominates, accompanied by low mineralizing temperatures. In situ S isotope results indicate that the source of mineralizing materials in Stage I (2.52–4.48‰) were magmatic rocks, whereas the markedly higher δ34S values in stages II–III (4.68–6.60‰) suggest sulfur isotope leaching from sedimentary rocks by meteoric water as the main source. The LA–ICP–MS data of pyrite in the Xiaorequanzi Cu deposit suggest that Py1 was formed through volcanic processes, whereas Py2 and Py3 exhibited epithermal characteristics. Throughout the mineralization process, a trend in increasing oxygen and decreasing sulfur fugacity occurred, accompanied by a decreased mineralization temperature. This observation corresponds with the temperature data derived from the fluid inclusions. Additionally, the principal components of different generations of pyrite segregated as two clusters representing the VMS (Stage I) and epithermal mineralization (stages II–III). In summary, based on comprehensive research and previous geochronological studies, it is suggested that the Xiaorequanzi Cu deposit experienced two mineralization stages. The early stage is related to the volcanic activity of the Early Carboniferous (354 Ma), whereas the later stage is associated with Carboniferous–Permian (266–264 Ma) volcanic intrusions. Full article
(This article belongs to the Section Mineral Deposits)
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21 pages, 7220 KiB  
Article
Flotation Enrichment of Micro- and Nanosilica Formed During the Production of Silicon and Ferrosilicon
by Antonina I. Karlina, Yuliya I. Karlina and Vitaliy A. Gladkikh
Minerals 2024, 14(11), 1165; https://doi.org/10.3390/min14111165 - 17 Nov 2024
Viewed by 501
Abstract
This paper presents the results of experiments conducted on the flotation separation of cyclone dust particles. The flotation process was conducted using a laboratory flotation apparatus comprising three chambers. Experimental tests supported theoretical results of the theoretical reasoning and justification for the choice [...] Read more.
This paper presents the results of experiments conducted on the flotation separation of cyclone dust particles. The flotation process was conducted using a laboratory flotation apparatus comprising three chambers. Experimental tests supported theoretical results of the theoretical reasoning and justification for the choice of parameters that the flotation process should have in order to extract particles of such small sizes. Furthermore, this work elucidates the concept of “nanobubbles” and substantiates their viability for use in the flotation of nanoparticles, given that bubbles of such a magnitude are firmly affixed to the hydrophobic surface of particles. Bubbles of a larger size than nanoparticles will float both hydrophobic and hydrophilic particles. The effective flotation of cyclone dust from the gas cleaning of silicon and ferroalloy production provided two materials as a result. The experiments yielded insights into the rational technological parameters of the flotation mode for obtaining new products. These insights were gleaned from the preliminary conditioning (conditioning time from 0.5 to 1.5 h) of wet cyclone dust (dry dust weight of 4 kg) with liquid glass (1.4 g per 1 dm3 of pulp) in a cavitation unit at a pH value of 8.5. The flotation process was conducted in a three-chamber flotation apparatus with a volume of 0.02 m3 for a duration of 90 min, utilizing a pneumohydraulic aerator with air suction from the atmosphere. In this instance, the pulp was conveyed via a pump at a pressure of 0.4 MPa from the initial cleansing chamber into the aerator. During the flotation process, kerosene (1 mg per 1 dm3 of pulp) and pine oil (2 mg per 1 dm3 of pulp) were added as additives. The resulting products were silicon dioxide (95%) and carbon nanoparticles (94%). Full article
(This article belongs to the Section Mineral Processing and Extractive Metallurgy)
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14 pages, 5051 KiB  
Article
Exploration of the Subsurface Three-Dimensional Structure in Rare Earth Ore Areas Using Electrical Resistivity Tomography: A Case Study in Changting, Fujian, China
by Yingchun Tang, Ping Liu, Shujing Jia, Yang Yang, Yajun Mo and Jie Zhu
Minerals 2024, 14(11), 1164; https://doi.org/10.3390/min14111164 - 17 Nov 2024
Viewed by 446
Abstract
The development of fracture zones (broken zones) and underground karst rivers in underlying granite can significantly reduce the recovery rate of ion-adsorption-type rare earth ores. Additionally, leaching solutions flowing along unfavorable geological formations can lead to environmental pollution. Therefore, investigating the development of [...] Read more.
The development of fracture zones (broken zones) and underground karst rivers in underlying granite can significantly reduce the recovery rate of ion-adsorption-type rare earth ores. Additionally, leaching solutions flowing along unfavorable geological formations can lead to environmental pollution. Therefore, investigating the development of fracture zones (leakage channels) in granite basements is of great significance. In Changting, Fujian, China, several methods have been used in exploration areas (C1 and C2) to study the characteristics of rare ores. This study has focused on the stratigraphic and structural characteristics of the C2 exploration area. Twelve exploration profiles were designed to collect data using electrical resistivity tomography, and a deep electrical structure model of the study area was obtained through inverse calculations. The results indicated that the exploration profiles effectively delineated the thickness of the weathered granite layer and the spatial distribution characteristics of the deep-seated fault structures, which were consistent with the drilling results within the study area. These findings provide important reference materials for the assessment of ion-adsorption-type rare earth ore reserves, blocking leakage channels, and the layout of recovery tunnels. Full article
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28 pages, 25856 KiB  
Article
Geophysical Methods Applied to the Mineralization Discovery of Rare-Earth Elements at the Fazenda Buriti Alkaline Complex, Goiás Alkaline Province, Brazil
by Fabrício Pereira dos Santos, Marcelo Henrique Leão-Santos, Welitom Rodrigues Borges and Patrícia Caixeta Borges
Minerals 2024, 14(11), 1163; https://doi.org/10.3390/min14111163 - 17 Nov 2024
Viewed by 539
Abstract
In this case study, exploratory techniques were applied for the selection of potential targets for rare-earth elements (REEs) in the Fazenda Buriti Mafic–Ultramafic Complex, part of the Goiás Alkaline Province. The results of the processing and interpretation of aeromagnetic and radiometric data associated [...] Read more.
In this case study, exploratory techniques were applied for the selection of potential targets for rare-earth elements (REEs) in the Fazenda Buriti Mafic–Ultramafic Complex, part of the Goiás Alkaline Province. The results of the processing and interpretation of aeromagnetic and radiometric data associated with the direct measurements of magnetic susceptibility and radiometry in rock samples collected in the study area allowed for the characterization and delimitation of the geological units. The application of Boolean logic in the radiometric data of uranium (U), thorium (Th), and the U/Th ratio allowed for the generation of a prospective map with the delimitation of two exploration targets. A 100 m deep exploratory drill hole was drilled at the main target, intercepting REE mineralization and validating the developed prospective technique. The results contributed to the detailing of a 1:25,000 scale geological map and the interpretation of shallow and deep magnetic structures. Petrophysical data allowed for the estimation of the magnetite content in the main units of the study area. The delimitation of targets with the applied method proved to be efficient after positive geochemical results for REE from the drilled rocks. The total sum of ∑REEs reached 19,629 ppm in the superficial part of the hole and 3,560 ppm in the fresh rock. Mineralogical results in two follow-up drill core samples indicated that monazite was the main REE mineral. Total REE ranged from 34,746 ppm in HG1 to 30,017 ppm in HG2, with LREEs in its majority. The bulk and clay XRD analyses indicated that monazite consisted of 5.7% (HG1) and 5.1% (HG2). The mineral abundance from the TIMA-X analysis indicated 4.2% (HG1) and 4.4% (HG2) in monazite content. Full article
(This article belongs to the Section Mineral Exploration Methods and Applications)
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35 pages, 1549 KiB  
Review
Applications of Kuz–Ram Models in Mine-to-Mill Integration and Optimization—A Review
by Manuel Saldana, Sandra Gallegos, Dayana Arias, Iván Salazar, Jonathan Castillo, Eleazar Salinas-Rodríguez, Alessandro Navarra, Norman Toro and Luis A. Cisternas
Minerals 2024, 14(11), 1162; https://doi.org/10.3390/min14111162 - 17 Nov 2024
Viewed by 609
Abstract
The Mine-to-Mill (M2M) approach aims to enhance efficiency and reduce costs in the mineral processing industry by optimizing the mining and processing stages. M2M integrates orebody characterization, blasting, and downstream processes, such as grinding and flotation, demonstrating that material fragmentation directly impacts downstream [...] Read more.
The Mine-to-Mill (M2M) approach aims to enhance efficiency and reduce costs in the mineral processing industry by optimizing the mining and processing stages. M2M integrates orebody characterization, blasting, and downstream processes, such as grinding and flotation, demonstrating that material fragmentation directly impacts downstream efficiency. This review studies the development and applications of fragmentation models in M2M integration and optimization, finding that their study is divided into three phases. In the first, the potential of M2M is investigated through simulation models that improve fragmentation in blasting to optimize grinding. The second focuses on the practical application of these models in mines, while the third phase integrates geometallurgical data into mine block models, enhancing production planning and selective ore extraction. The M2M integration has demonstrated significant improvements in plant performance, particularly in increasing grinding efficiency through optimized blast fragmentation. The literature also emphasizes the role of optimizing crushing and grinding conditions through models and circuit adjustments to enhance performance and reducing energy consumption. Geometallurgy plays a crucial role in plant optimization by identifying areas with better processing characteristics and adjusting operating parameters to maximize efficiency. Recent studies have shown how the implementation of integrated models can increase the profitability and sustainability of mining operations. Full article
(This article belongs to the Section Mineral Processing and Extractive Metallurgy)
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12 pages, 2884 KiB  
Article
Establishing a UG2 Pillar Strength Formula in South African Platinum Mines
by Bryan Watson, Tatenda Maphosa, Willie Theron, Noel Fernandes, Thomas Stacey, Andrew Morgan, Andrew Carpede and Gunther Betz
Minerals 2024, 14(11), 1161; https://doi.org/10.3390/min14111161 - 17 Nov 2024
Viewed by 462
Abstract
In this study, the peak strength of chromitite pillars in South African platinum mines is re-examined by comparing laboratory tests to the Upper Group 2 (UG2) PlatMine pillar strength formula and underground measurements. The laboratory results were stronger than the underground measurements and [...] Read more.
In this study, the peak strength of chromitite pillars in South African platinum mines is re-examined by comparing laboratory tests to the Upper Group 2 (UG2) PlatMine pillar strength formula and underground measurements. The laboratory results were stronger than the underground measurements and the strength predicted by the PlatMine formula. The rock mass strength in the PlatMine formula (‘k-value’) was about 70% of the laboratory tests performed on a 50 mm diameter sample. This finding agrees with other researchers who have compared the rock mass strength to laboratory-determined uniaxial compressive strengths. The laboratory tests, underground measurements, and the PlatMine formula all show that the pillars are significantly stronger than traditionally accepted. This finding can help the UG2 mining industry to improve extraction ratios significantly by adopting the PlatMine formula, particularly at deeper levels where bord-and-pillar workings are used. The results presented in this paper will achieve significant revenue creation in the mine where the underground measurements were made. Full article
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17 pages, 2851 KiB  
Article
Artificial Neural Network-Based Non-Linear Modeling and Simulation of CaO-SiO2-Al2O3-MgO Blast Furnace Slag Viscosity
by Patrick dos Anjos, Jorge Luís Coleti, Eduardo Junca, Felipe Fardin Grillo and Marcelo Lucas Pereira Machado
Minerals 2024, 14(11), 1160; https://doi.org/10.3390/min14111160 - 16 Nov 2024
Viewed by 544
Abstract
Blast furnace slags are formed by CaO-SiO2-Al2O3-MgO systems and have several physical characteristics, one of which is viscosity. Viscosity is an important variable for the operation and blast furnace performance. This work aimed to model viscosity through [...] Read more.
Blast furnace slags are formed by CaO-SiO2-Al2O3-MgO systems and have several physical characteristics, one of which is viscosity. Viscosity is an important variable for the operation and blast furnace performance. This work aimed to model viscosity through linear and non-linear models in order to obtain a model with precision and accuracy. The best model constructed was a non-linear model by artificial neural networks that presented 23 nodes in the first hidden layer and 24 nodes in the second hidden layer with 6 input variables and 1 output variable named ANN 23-24. ANN 23-24 obtained better statistical evaluations in relation to 11 different literature equations for predicting viscosity in CaO-SiO2-Al2O3-MgO systems. ANN 23-24 was also subjected to numerical simulations in order to demonstrate the validation of the non-linear model and presented applications such as viscosity prediction, calculation of the inflection point in the viscosity curve by temperature, the construction of ternary diagrams with viscosity data, and the construction of iso-viscosity curves. Full article
(This article belongs to the Special Issue Characterization and Reuse of Slag)
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32 pages, 9777 KiB  
Article
Geochemical Characterization of and Exploration Guide for the World-Class Mafic–Siliciclastic-Hosted Touro VMS Cu Deposit, Northwestern Iberian Peninsula
by Pablo Nuñez, Alvaro Rubio, Daniel Arias, Jorge Fuertes-Blanco, Fernando Cortés, Fernando Díaz-Riopa and Agustin Martin-Izard
Minerals 2024, 14(11), 1159; https://doi.org/10.3390/min14111159 - 16 Nov 2024
Viewed by 629
Abstract
A geochemical study was conducted on the Touro deposit, which is situated within the Iberian Variscan Massif on the allochthonous terrain of the Galicia–Tras-os-Montes Zone. This study encompassed both mineralogical and geochemical analyses of the host rocks, with a particular focus on the [...] Read more.
A geochemical study was conducted on the Touro deposit, which is situated within the Iberian Variscan Massif on the allochthonous terrain of the Galicia–Tras-os-Montes Zone. This study encompassed both mineralogical and geochemical analyses of the host rocks, with a particular focus on the high-grade Fornás metamorphic unit of the Órdenes Complex. The deposit is composed of massive and semi-massive sulfides, the host rocks are amphibolites and paragneisses, and the ore is hosted in garnet amphibolites and mineralized paragneisses. A microscopic study of thin sections and over 300 electron probe microanalyses on various minerals were conducted with the objective of geochemical characterization. Furthermore, a study of approximately 6000 samples processed by mining companies for multielement analyses of over 1350 drill cores was conducted to geochemically characterize the host and mineralized rocks for use as exploration guides. Additionally, five samples underwent Sm-Nd isotope analysis. The data from the Touro Cu (Zn-Co) deposit are consistent with its classification as a mafic–siliciclastic (Besshi-type) VMS deposit constructed in a back-arc environment during the Ordovician period. Following burial and high-grade metamorphism during the Middle Devonian period, these rocks were subsequently exposed during the later Variscan deformation phases, resulting in the formation of the Arinteiro antiform. Full article
(This article belongs to the Special Issue Mineralization and Geochemistry of VMS Deposits)
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17 pages, 18884 KiB  
Article
Timing of Ore Mineralisation in Deposits of the Baikal-Muya Belt and the Barguzin-Vitim Super-Terrain (Transbaikalie)
by Vadim A. Vanin, Alexei V. Ivanov, Viktor A. Gorovoy, Alexander E. Budyak and Nikolay S. Bortnikov
Minerals 2024, 14(11), 1158; https://doi.org/10.3390/min14111158 - 15 Nov 2024
Viewed by 453
Abstract
The study was aimed at dating of Au ores from the Yubileinoe, Irokinda and Uryakh deposits located in the Baikal-Muya fold belt and Pb-Zn ores from the Ozernoe deposit in the Barguzin-Vitim super-terrain (Transbaikalia, Russia). The 40Ar/39Ar ages on pyrite-encapsulated [...] Read more.
The study was aimed at dating of Au ores from the Yubileinoe, Irokinda and Uryakh deposits located in the Baikal-Muya fold belt and Pb-Zn ores from the Ozernoe deposit in the Barguzin-Vitim super-terrain (Transbaikalia, Russia). The 40Ar/39Ar ages on pyrite-encapsulated sericite of gold-bearing quartz sampled from veins in the Yubileinoe, Irokinda and Uryakh deposits are 265 ± 33 Ma, 276 ± 13 Ma and 287 ± 7 Ma, respectively. The age of disseminated mineralisation in the Ozernoe deposit is 329 ± 19 Ma. The results of this study and previously published data suggest two stages of ore mineralisation at Transbaikalia: 330–320 Ma for the disseminated mineralisation and 290–270 Ma for the vein mineralisation. Irrespective of the location and the nature of the host rocks, the former and the latter mineralisation are transiently associated with the initial and final stages of the emplacement of the Angara-Vitim granitic batholith. The granitoids provided heat and possibly fluids, while Au, Pb and Zn were sourced from the host rocks. Gold deposits to the north and south of the batholith are generally older and younger, respectively, and were formed by different geological processes. Full article
(This article belongs to the Special Issue Metallogenesis of the Central Asian Orogenic Belt)
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29 pages, 7954 KiB  
Article
The Evolution of Neoproterozoic Mantle Peridotites Beneath the Arabian–Nubian Shield: Evidence from Wadi Sodmein Serpentinites, Central Eastern Desert, Egypt
by Khaled M. Abdelfadil, Asran M. Asran, Hafiz U. Rehman, Mabrouk Sami, Alaa Ahmed, Ioan V. Sanislav, Mohammed S. Fnais and Moustafa M. Mogahed
Minerals 2024, 14(11), 1157; https://doi.org/10.3390/min14111157 - 15 Nov 2024
Viewed by 710
Abstract
Serpentinites make up one of the most significant rock units associated with primary suture zones throughout the ophiolite sequence of the Arabian–Nubian Shield. Wadi Sodmein serpentinites (WSSs) represent dismembered parts of the oceanic supra-subduction system in the central Eastern Desert of Egypt. In [...] Read more.
Serpentinites make up one of the most significant rock units associated with primary suture zones throughout the ophiolite sequence of the Arabian–Nubian Shield. Wadi Sodmein serpentinites (WSSs) represent dismembered parts of the oceanic supra-subduction system in the central Eastern Desert of Egypt. In this context, we present whole-rock major, trace, and rare earth elements (REE) analyses, as well as mineral chemical data, to constrain the petrogenesis and geotectonic setting of WSS. Antigorite represents the main serpentine mineral with minor amounts of chrysotile. The predominance of antigorite implies the formation of WSS under prograde metamorphism, similar to typical metamorphic peridotites of harzburgitic protolith compositions. The chemistry of serpentinites points to their refractory composition with notably low Al2O3, CaO contents, and high Mg# (90–92), indicating their origin from depleted supra-subduction zone harzburgites that likely formed in a forearc mantle wedge setting due to high degrees of hydrous partial melting and emplaced owing to the collision of the intra–oceanic arc with Meatiq Gneisses. Spinels of WSS generally exhibit pristine compositions that resemble those of residual mantle peridotites and their Cr# (0.625–0.71) and TiO2 contents (<0.05 wt%) similar to forearc peridotite spinels. Moreover, WSS demonstrates a significant excess of fluid mobile elements (e.g., Th, U, Pb), compared to high-field strength elements (e.g., Ti, Zr, Nb, Ta), implying an interaction between mantle peridotites and fluids derived from the oceanic subducted-slab. The distinct U-shaped REE patterns coupled with high Cr# of spinel from WSS reflect their evolution from mantle wedge harzburgite protolith that underwent extensive melt extraction and re-fertilized locally. Full article
(This article belongs to the Special Issue Mineralogy, Chemistry, Weathering and Application of Serpentinite)
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25 pages, 10778 KiB  
Article
Formation of Ferrogabbro Through Fe-Ti Oxide Accumulation Under Moderate Oxidation Conditions: Insights from the Dashanshu Intrusion in the Emeishan Large Igneous Province, SW China
by Manrong Jiang, Wenhao Liu, Bo Zu and Weihua Wang
Minerals 2024, 14(11), 1156; https://doi.org/10.3390/min14111156 - 15 Nov 2024
Viewed by 449
Abstract
The mechanism of iron enrichment in ferrogabbro remains a controversial subject. This study provides valuable insights derived from the Dashanshu intrusion, located in the Emeishan Large Igneous Province in southwestern China, which features ferrogabbro with a notably high iron content (total Fe2 [...] Read more.
The mechanism of iron enrichment in ferrogabbro remains a controversial subject. This study provides valuable insights derived from the Dashanshu intrusion, located in the Emeishan Large Igneous Province in southwestern China, which features ferrogabbro with a notably high iron content (total Fe2O3 reaching up to 21.6 wt.%). The ferrogabbro samples exhibit distinctive petrographic features, including the early crystallization of plagioclase prior to pyroxenes, amphibole replacing pyroxenes, and magnetite–ilmenite intergrowth filling the interstices between plagioclase and pyroxenes. A quantitative mineral analysis based on micro-X-ray fluorescence element mapping reveals a positive correlation between Fe-Ti oxides and bulk-rock iron contents, suggesting that the formation of ferrogabbro is primarily attributed to the accumulation of Fe-Ti oxides. Petrographic characteristics combined with oxygen fugacity determinations indicate that the primitive magma had a low content of water and was moderately oxidized (ΔFMQ − 0.13 to ΔFMQ + 1.35). These conditions suppress the early crystallization of Fe-Ti oxides, thereby allowing for an enrichment of iron in the residual magma. Following the crystallization of plagioclase and pyroxenes, increased water content—evidenced by amphibole replacing pyroxenes—triggers extensive crystallization of Fe-Ti oxides. Due to their late-stage crystallization, these oxides do not settle within the magma, which possesses a high crystallinity (>50%) and consequently exhibits non-Newtonian fluid behavior. This results in the localized accumulation of Fe-Ti oxides and the formation of a ferrogabbro layer. However, the late-stage crystallization of Fe-Ti oxides also impedes the sinking and flow-sorting processes that are essential for the development of economically valuable Fe-Ti oxide layers. This may account for the lack of an economically valuable Fe-Ti oxide layer within the Dashanshu intrusion. Full article
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20 pages, 4342 KiB  
Article
Spent NCM Lithium-Ion Batteries: Potential Evaluation of Mechanical Pretreatment for Recycling
by Priscila Silva Silveira Camargo, Maryanne Hoffmann Cardoso, Roberta dos Reis Costantin, Marcelo Pilotto Cenci, Felipe Antonio Lucca Sánchez, Angela Cristina Kasper and Hugo Marcelo Veit
Minerals 2024, 14(11), 1155; https://doi.org/10.3390/min14111155 - 15 Nov 2024
Viewed by 608
Abstract
Recent increases in the demand for automotive lithium-ion batteries (LIBs) have led to higher needs for critical materials like lithium, cobalt, nickel, and graphite. Consequently, recovering materials from spent batteries has gained importance. This study aimed to (1) develop a mechanical pretreatment method [...] Read more.
Recent increases in the demand for automotive lithium-ion batteries (LIBs) have led to higher needs for critical materials like lithium, cobalt, nickel, and graphite. Consequently, recovering materials from spent batteries has gained importance. This study aimed to (1) develop a mechanical pretreatment method for separating and concentrating materials from spent NCM811 cells and (2) evaluate the economic, environmental, and shortage potentials of these fractions. The pretreatment involved grinding and granulometric separation, producing six particle-size fractions. The main novelty of the study was the assessment to identify the particle size fractions which are priorities for recycling for decision-making by recycling companies, optimizing their resources and efforts. Analysis showed that the finest fraction (n < 0.5 mm) had 85% of lithium, 77.4% of cobalt, 75.1% of manganese, and 68.5% of nickel. This fraction represented 40.4% of the processed mass and had the highest economic value (USD 3669/ton NCM cell). This fraction was also prioritized for recycling due to its superior environmental impact (103,788 kg CO2-eq/ton NCM cell) and scarcity considerations. Furthermore, the black mass of NCM was the priority for recycling and had greater economic, environmental, and supply risk potential than the black mass of LFP cells. Full article
(This article belongs to the Section Mineral Processing and Extractive Metallurgy)
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25 pages, 7774 KiB  
Article
Petroleum System Evaluation: Hydrocarbon Potential and Basin Dynamics in Abu Darag Sub-Basin, Northern Gulf of Suez (Egypt)
by Sherif Farouk, Mohamed Fagelnour, Amr S. Zaky, Mohamed Arafat, Ahmad Salama, Khaled Al-Kahtany, Thomas Gentzis and Luigi Jovane
Minerals 2024, 14(11), 1154; https://doi.org/10.3390/min14111154 - 15 Nov 2024
Viewed by 520
Abstract
The Abu Darag sub-basin in Egypt is a significant hydrocarbon province. This study provides the first thorough evaluation of the petroleum system in the Northern Gulf of Suez, specifically targeting regions with tectonically influenced paleo highs. The research is novel in its holistic [...] Read more.
The Abu Darag sub-basin in Egypt is a significant hydrocarbon province. This study provides the first thorough evaluation of the petroleum system in the Northern Gulf of Suez, specifically targeting regions with tectonically influenced paleo highs. The research is novel in its holistic approach, linking tectonic activity with hydrocarbon generation and accumulation, particularly in the Nukhul Formation. In the NDARAG-1 well, with the Nukhul Formation serving as its main reservoir, petrophysical analysis estimates an average net pay of 126 ft in the Nukhul Formation, with 19% average shale volume, 17% average effective porosity, and 57% average water saturation. Geochemical evaluation of the shales in the Thebes, Matulla, Raha, and Nubia-A formations indicate source rock potential ranging from fair to very good, with TOC values between 0.5 wt% and 5.4 wt%. The burial history model outlines gradual subsidence and sediment deposition from the Paleozoic to the Early Cretaceous, followed by significant compression and uplift during the Late Cretaceous. Early oil generation in the Nubia-A Lower shales began during the Early Cretaceous (~132 Ma) at a depth of 4000 ft while it occurred in the Early Miocene (~22 Ma) at a depth of 7400 ft. The Nubia-A Lower Member is identified as the key source rock, with vitrinite reflectance values above 0.70%. Continuous subsidence during the Eocene led to the deposition of the Nukhul, Rudeis, and Kareem formations. Oil generation in the Nubia-A Lower shales occurred during both the Early Cretaceous and Early Miocene. The main risk to hydrocarbon accumulation in the Abu Darag sub-basin is related to potential seal failures due to the erosion and/or non-deposition of the Belayim, South Gharib, and Zeit evaporites. The only producing wells are situated in the northwest of the study area, where conditions are conducive to hydrocarbon entrapment and preservation, and secondary migration has occurred in a northwestward direction. Full article
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35 pages, 9267 KiB  
Article
Petrogenesis of Late Stenian Syn-Orogenic A-Type Granites in the Chhotanagpur Gneissic Complex and Eastern Indian Shield
by Bapi Goswami, Ankita Basak, Yoann Gréau and Chittaranjan Bhattacharyya
Minerals 2024, 14(11), 1153; https://doi.org/10.3390/min14111153 - 14 Nov 2024
Viewed by 554
Abstract
We report the petrogenesis of arfvedsonite granites from the Dimra Pahar pluton in the Chhotanagpur Gneissic Complex based on petrology, whole-rock chemistry, mineral chemistry, and La-ICP-MS zircon U-Pb ages and Hf-Lu isotopic analyses. These granites are dominantly peralkaline, occasionally peraluminous, and demonstrate features [...] Read more.
We report the petrogenesis of arfvedsonite granites from the Dimra Pahar pluton in the Chhotanagpur Gneissic Complex based on petrology, whole-rock chemistry, mineral chemistry, and La-ICP-MS zircon U-Pb ages and Hf-Lu isotopic analyses. These granites are dominantly peralkaline, occasionally peraluminous, and demonstrate features of A1-type granites. The magma was emplaced at a shallow depth and had a high liquidus temperature, fO2 (>NNO), and water saturation. The zircons exhibit three distinct U-Pb isotopic ages. The oldest (1324 ± 6 Ma), large-sized inherited zircons (εHf(t) = +1.65 to +7.64), show complex zoning and signs of partial resorption. The euhedral, prismatic-bipyramidal zircons displaying oscillatory zoning (εHf(t) = −3.43 to +1.43) reveal a crystallization age of 1046 ± 7 Ma. Their thin periphery (εHf(t) = −3.23 to +0.27) grew during retrograde metamorphism (995 ± 6 Ma). The whole-rock geochemistry and the Hf-isotope values imply that the parental magma of these granites resulted from the anatexis of metasomatized lithospheric mantle sources. These granites intruded in a syn-orogenic (syn-collisional exhumation) stage of the orogeny. Full article
(This article belongs to the Special Issue Geochronology and Geochemistry of Alkaline Rocks)
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