Minerals

30 pages, 11844 KiB

Open AccessArticle

Enhancing Thin Coal Seam Detection in Eastern Indian Coalfields Using ICWT-Decon-Based Seismic Attributes and Acoustic Impedance Inversion

by Naresh Kumar Seelam, Thinesh Kumar, Santosh Dhubia, Gangumalla Srinivasa Rao and Sanjit Kumar Pal

Minerals 2024, 14(9), 920; https://doi.org/10.3390/min14090920 (registering DOI) - 7 Sep 2024

Abstract

A high-resolution seismic survey (HRSS) is often used in coal exploration to bridge the data gap between two consecutive boreholes and avoid ambiguity in geological interpretation. The application of high-resolution seismic surveys in the Indian context is challenging as the delineation of thin [...] Read more.

A high-resolution seismic survey (HRSS) is often used in coal exploration to bridge the data gap between two consecutive boreholes and avoid ambiguity in geological interpretation. The application of high-resolution seismic surveys in the Indian context is challenging as the delineation of thin non-coal layers within the coal layer requires a very high seismic data resolution. However, conventional seismic processing techniques fail to resolve thin coal/non-coal layers and faults, which is crucial for the precise estimation of coal resources and mine economics. To address these issues, we applied the inverse continuous wavelet transform deconvolution (ICWT-Decon) technique to post-stack depth-migrated seismic sections. We examined the feasibility of the ICWT-Decon technique in both a synthetic post-stack depth-migrated model and 2D/3D seismic data from the North Karanpura and Talcher Coalfields in Eastern India. The results offered enhanced seismic sections, attributes (similarity and sweetness), and acoustic inversion that aided in the precise positioning of faults and the delineation of a thin non-coal layer of 4.68 m within a 16.7 m coal seam at an approximate depth of 450 m to 550 m. This helped in the refinement of the resource estimation from 74.96 MT before applying ICWT-Decon to 55.92 MT afterward. Overall, the results of the study showed enhancements in the seismic data resolution, the better output of seismic attributes, and acoustic inversion, which could enable more precise lithological and structural interpretation. Full article

(This article belongs to the Special Issue Seismics in Mineral Exploration)

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23 pages, 6810 KiB

Open AccessArticle

Fit-for-Purpose Model of HP500 Cone Crusher in Size Reduction of Itabirite Iron Ore

by Brena Karolyne Nunes da Rocha, Túlio Moreira Campos, Júlio Silva and Luís Marcelo Tavares

Minerals 2024, 14(9), 919; https://doi.org/10.3390/min14090919 (registering DOI) - 7 Sep 2024

Abstract

Cone crushers have a central role in the processing of quarry rocks, besides coarser ore preparation in several mineral processing plants. This is particularly true in the case of Itabirite iron ore preparation plants in Brazil, so optimizing their performance is of central [...] Read more.

Cone crushers have a central role in the processing of quarry rocks, besides coarser ore preparation in several mineral processing plants. This is particularly true in the case of Itabirite iron ore preparation plants in Brazil, so optimizing their performance is of central importance for reaching maximum productivity of the circuit. The work presents results of modeling the HP500 cone crusher in operation in an industrial plant in Brazil (Minas Rio), from surveys carried out over a few years with different feeds and crushing conditions. A version of the Andersen–Whiten cone crusher model was implemented in the Integrated Extraction Simulator featuring a non-normalizable breakage response and a fit-for-purpose throughput model. The results demonstrate the good ability of the model to predict crusher performance when dealing with different closed-side settings and feed size distributions. Full article

(This article belongs to the Special Issue Modelling of Particle Behaviour during Mineral Processing)

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21 pages, 11571 KiB

Open AccessArticle

Characteristics of Micropore-Throat Structures in Tight Oil Reservoirs: A Case Study of the Jiufotang Formation in the Houhe Region, NE China

by Guolong Zhang and Chenglong Ma

Minerals 2024, 14(9), 918; https://doi.org/10.3390/min14090918 - 6 Sep 2024

Abstract

In order to examine further the characteristics of micropore-throat structures of the tight oil reservoir in the Jiufotang Formation in the Houhe region, this study used whole rock X-ray diffraction, routine physical property analysis, and routine thin section observations to analyze the material [...] Read more.

In order to examine further the characteristics of micropore-throat structures of the tight oil reservoir in the Jiufotang Formation in the Houhe region, this study used whole rock X-ray diffraction, routine physical property analysis, and routine thin section observations to analyze the material composition and physical properties of the tight oil reservoir. CT scanning, high-pressure mercury infiltration, and other test methods were employed to analyze the characteristics of the pore-throat structures in the tight oil reservoir. In addition, the Pearson correlation coefficients quantified the relationships between nine parameters and pore-throat structures. The parameters with high correlations were optimized for analysis, and a comprehensive classification scheme for micropore-throat structures in the tight oil reservoir in the study area was established. The results show that the reservoir in the Jiufotang Formation in the Houhe region is composed of feldspathic and lithic arkosic sandstone, with feldspar and clast pore dissolution pores as the main type of reservoir pore space. The tight oil reservoir has small pore-throat radius, complex structures, poor connectivity, and high heterogeneity. It generally contains micron-sized pores with submicron to nanometer throat widths and small- and medium-sized pores to fine micropore-throat structures. Porosity, permeability, coefficient of variation, skewness coefficient, and average pore-throat radius, were selected for k-means cluster analysis. The micropore-throat structures of the tight oil reservoir were divided into three categories: classes I, II, and III. The study area is dominated by class II pore throats, accounting for 58%. Diagenesis mainly controls the pore-throat structure. These results provide an effective reference for the identification and evaluation of favorable sweet spots in tight oil reservoirs in similar blocks in China. Full article

(This article belongs to the Topic Petroleum Geology and Geochemistry of Sedimentary Basins)

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18 pages, 4558 KiB

Open AccessArticle

Mechanical Properties, Failure Modes, and Damage Development of Stratified Cemented Tailings Backfill under Uniaxial Compression

by Wenbin Xu, Yalun Zhang, Wei Chen, Tong Sun and Yilin Sang

Minerals 2024, 14(9), 917; https://doi.org/10.3390/min14090917 - 6 Sep 2024

Abstract

Layered cemented filling leads to a layered composite structure of cemented tailings backfill (CTB) composed of high-strength top and bottom layers, as well as a low-strength middle layer. To solve the problem of the low mechanical properties of the middle layer caused by [...] Read more.

Layered cemented filling leads to a layered composite structure of cemented tailings backfill (CTB) composed of high-strength top and bottom layers, as well as a low-strength middle layer. To solve the problem of the low mechanical properties of the middle layer caused by layered filling, this study proposes the concept of an enhance layer, that is, an enhance layer is added to the middle weak layer to improve its overall mechanical properties. To explore the characteristics of strength, failure modes, energy dissipation, and progressive damage of stratified cemented tailings backfill (SCTB) with varying layered structures, the uniaxial compressive tests of SCTB specimens with enhance layers c/t of 1:15, 1:10, and 1:6, as well as height proportions of 0.1, 0.2, and 0.3, are examined. The results show that the elastic modulus and uniaxial compressive strength (UCS) of SCTB samples increase with the height ratio and cement-to-tailings ratio of the enhance layer. The elastic modulus and strength of SCTB specimens is more sensitive to the height ratio of the enhance layer than the c/t ratio. Moreover, the SCTB specimens mainly manifested as tensile failure of the upper layer and lower layer, but they did not penetrate the entire specimen. The propagation of cracks is limited by the addition of the enhance layer. The SCTB specimens have stronger plastic deformation ability, and a large part of the all-strain energy is dissipated in the shape of plastic failure. In addition, a constitutive model for damage in SCTB samples has been developed. The SCTB samples with a reasonable structure can also achieve sufficient strength compared to directly increasing the c/t ratio of CTB specimens while reducing the cost of cemented tailings backfill preparation. This approach reduces the carbon footprint of the mining industry and improved the overall mechanical properties and stability of the stratified cemented tailings backfill. This study provides a new approach for high-stage subsequent stope backfilling. The findings will offer guidance for the design of a layered filling mining method. Full article

(This article belongs to the Special Issue Advances in Mine Backfilling Technology and Materials)

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25 pages, 10774 KiB

Open AccessArticle

Recycling of Au during Serpentinization of Ultramafic Rocks: A Case Study from Neoproterozoic Forearc Ophiolites, Egypt

by Basem Zoheir, Astrid Holzheid, Aliaa Diab, Azza Ragab, Fatma Deshesh and Amr Abdelnasser

Minerals 2024, 14(9), 916; https://doi.org/10.3390/min14090916 - 6 Sep 2024

Abstract

Gold, along with other highly siderophile elements, is hosted by Fe-Ni sulfide phases within peridotites and mantle melts. In this context, the lithospheric mantle emerges as a principal reservoir, providing materials crucial for the inception, augmentation, conveyance, and genesis of auriferous CO₂ [...] Read more.

Gold, along with other highly siderophile elements, is hosted by Fe-Ni sulfide phases within peridotites and mantle melts. In this context, the lithospheric mantle emerges as a principal reservoir, providing materials crucial for the inception, augmentation, conveyance, and genesis of auriferous CO₂-rich mantle fluids. EPMA and laser ablation ICP-MS data, integrated with petrographic and SEM studies, were used to assess the transfer of base and precious metals into the Earth’s crust, discerning between inputs from subduction-related processes and post-formation metasomatism. The study focuses on sulfide minerals in serpentinized peridotites of the Abu Dahr ophiolite in the Eastern Desert of Egypt. Originating in a supra-subduction setting during the Neoproterozoic era, the Abu Dahr peridotites underwent serpentinization and contain discrete sulfide minerals, including pentlandite, nickeloan pyrrhotite, millerite, chalcopyrite, and violarite. The uneven distribution of calcite ± magnesite ± serpentine veins throughout the host ophiolitic rocks reflects the intricate interplay of serpentinization and carbonation, as fO₂ and fCO₂ conditions fluctuated. Geochemical data of the host rocks reveal a progressive geochemical evolution marked by concurrent silicification and carbonate alteration, driven by the interaction of ultramafic rocks with hydrothermal fluids, ultimately leading to the extensive silicification and formation of birbirite. The ICP-MS data show that pentlandite contains up to 6.11 ppm of Au, pyrrhotite up to 0.41 ppm, millerite 0.34 ppm, and violarite 0.12 ppm. The gold concentration in pentlandite is significantly higher than in pyrrhotite, millerite, and violarite, which exhibit lower but detectable levels of Au. Desulfurization reactions of sulfide minerals during progressive serpentinization triggered the release and redistribution of Au as well as base metals and highly siderophile elements. Published thermodynamic modeling at temperatures below 300 °C and pressures of 50 MPa closely replicates the mineral assemblage observed in the Abu Dahr ophiolites, including sulfide assemblages and variations in major elements such as Mg and Fe. This suggests that the serpentinization process, along with associated hydrothermal fluids, played a crucial role in the mobilization and redistribution of gold, particularly affecting its incorporation into secondary sulfides. The mobilization of Au and other highly siderophile elements during serpentinization occurred in an environment marked by strong oxidation, as indicated by the presence of acicular antigorite, magnetite, millerite, and goethite intergrowths. Full article

(This article belongs to the Special Issue In-Situ Microanalytical Techniques in Geological and Geochronological Research)

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16 pages, 15133 KiB

Open AccessArticle

Numerical Simulation and Experimental Study of a Deep-Sea Polymetallic Nodule Collector Based on the Coanda Effect

by Yan Li, Zhibin Han and Ziyuan Li

Minerals 2024, 14(9), 915; https://doi.org/10.3390/min14090915 - 6 Sep 2024

Abstract

Ore collection devices are important for the collection of deep-sea polymetallic nodules. Based on the CFD-DEM solid–liquid two-phase flow coupling calculation method, this paper simulated the rise and transport phases of polymetallic nodules using the Coanda effect ore collection device. The validity of [...] Read more.

Ore collection devices are important for the collection of deep-sea polymetallic nodules. Based on the CFD-DEM solid–liquid two-phase flow coupling calculation method, this paper simulated the rise and transport phases of polymetallic nodules using the Coanda effect ore collection device. The validity of the numerical simulation method was confirmed through experimental testing. On this basis, the effects of different working and structural parameters on the collection rate were studied. The results indicate that the flow rate of the collection jet and the bottom clearance were the primary factors affecting the collection rate of the polymetallic nodules. An increase in the collection jet flow rate leads to a substantial rise in the collection rate of polymetallic nodules. Conversely, an increase in bottom clearance results in a decrease in the collection rate. A collection rate exceeding 90% can be achieved in both scenarios: a 10 mm bottom clearance with an 8 m/s collection jet flow rate, and a 30 mm bottom clearance with a 10 m/s collection jet flow rate. The collection nozzle slant angle has no substantial impact on the collection rate, and the recommended collection nozzle slant angle is 35° to reduce energy loss. Full article

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14 pages, 3015 KiB

Open AccessArticle

Surface Chemistry and Flotation of Gold-Bearing Pyrite

by Seda Özçelik and Zafir Ekmekçi

Minerals 2024, 14(9), 914; https://doi.org/10.3390/min14090914 - 6 Sep 2024

Abstract

Gold grains are observed in a variety of forms, such as coarse-liberated native gold grains, and ultra-fine grains associated with sulfide or non-sulfide mineral particles, in the form of solid solution in sulfide minerals, mainly pyrite. In the flotation of gold ores, bulk [...] Read more.

Gold grains are observed in a variety of forms, such as coarse-liberated native gold grains, and ultra-fine grains associated with sulfide or non-sulfide mineral particles, in the form of solid solution in sulfide minerals, mainly pyrite. In the flotation of gold ores, bulk sulfide mineral flotation is generally applied to maximize gold recovery. This approach gives high gold recoveries, but it also causes the recovery of barren sulfide minerals (i.e., sulfide mineral particles with no gold content), which increases concentrate tonnage and transportation costs and reduces the grade sometimes to below the saleable limit (approx. 10 g/t Au). This study addresses the differences between gold-bearing and barren pyrite particles taken from various ore deposits and utilizes these differences for the selective flotation of gold-bearing pyrite. The laboratory scale flotation tests conducted on three pyrite samples having different cyanide soluble gold contents show that a selective separation between gold-bearing pyrite and barren pyrite particles could be achieved under specific flotation conditions. Gold recovery is correlated directly with the cyanide-soluble gold in the ore samples. Electrochemical experiments were conducted to elucidate the differences in surface properties of the two types of pyrite. The barren pyrite particles were more cathodic and prone to cathodic reduction of OH⁻ and depressant ions on the surface, and they could be depressed effectively without significantly affecting the gold-bearing particles. Full article

(This article belongs to the Special Issue Surface Chemistry and Reagents in Flotation)

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20 pages, 12039 KiB

Open AccessArticle

Innovative Seismic Imaging of the Platinum Deposits, Maseve Mine: Surface and In-Mine

by Moyagabo Rapetsoa, Musa Manzi, Ian James, Mpofana Sihoyiya, Raymond Durrheim and Michelle Pienaar

Minerals 2024, 14(9), 913; https://doi.org/10.3390/min14090913 - 6 Sep 2024

Abstract

Maseve Mine is located in the western limb of the Bushveld Complex, recognized as the largest layered igneous intrusion in the world. The study shows results from surface (SP1, SP2, and SP3) and tunnel (T3a, T3b, and TP4b) reflection seismic profiles, totaling 4150 [...] Read more.

Maseve Mine is located in the western limb of the Bushveld Complex, recognized as the largest layered igneous intrusion in the world. The study shows results from surface (SP1, SP2, and SP3) and tunnel (T3a, T3b, and TP4b) reflection seismic profiles, totaling 4150 m. Tunnel seismic data were acquired using a seismic landstreamer and spiked geophones with 5 m receiver and shot spacing, as well as a sledgehammer for shots due to space constraints and safety. The profiles, 10–50 m above mineral deposits, crossed major geological structures. Surface seismic profiles used cabled systems and wireless sensors with 5 m and 10 m receiver spacing, respectively, and a 500 kg drop hammer as a source with 10 m shot spacing. Despite high noise levels from mine infrastructure and power cables, a careful processing workflow enhanced target reflections. Interpretation was constrained using borehole data, geological models, and 2D/3D seismic modeling. The processed data exhibit gently dipping reflections associated with faults and dykes, imaging the target mineralization (Merensky Reef and Upper Group 2) and a possible extension. Tunnel seismic experiments demonstrated the application of seismic methods using in-mine infrastructure, while surface experiments proved efficient, illustrating small-scale seismic surveys’ capability to image the subsurface, adding value in active mining environments for exploration with cost-effective seismic equipment. Full article

(This article belongs to the Section Mineral Exploration Methods and Applications)

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23 pages, 22145 KiB

Open AccessArticle

Dynamic Enhanced Weighted Drainage Catchment Basin Method for Extracting Geochemical Anomalies

by Zijia Cui, Jianping Chen, Renwei Zhu, Quanping Zhang, Guanyun Zhou, Zhen Jia and Chang Liu

Minerals 2024, 14(9), 912; https://doi.org/10.3390/min14090912 - 5 Sep 2024

Abstract

Geochemical measurements of stream sediments are practical for small-scale mineral exploration. However, traditional grid interpolation methods cause element concentrations to diffuse and smooth out anomalies, particularly in complex terrains, making it challenging to reflect the actual distribution of elements accurately. We applied the [...] Read more.

Geochemical measurements of stream sediments are practical for small-scale mineral exploration. However, traditional grid interpolation methods cause element concentrations to diffuse and smooth out anomalies, particularly in complex terrains, making it challenging to reflect the actual distribution of elements accurately. We applied the Dynamic Enhanced Weighted Drainage Catchment Basin (DE-WDCB) method to enhance the retention and identification of local anomalies by limiting the scope of analysis to specific drainage units. This method reduces interference from varying background values across different watersheds, effectively enhancing geochemical element anomalies and aligning better with geomorphic conditions. The DE-WDCB method was tested in the Duobaoshan–Heihe area, a significant copper polymetallic mineral district in northeastern China. Compared with traditional grid interpolation methods, the DE-WDCB method retained and strengthened low and weak abnormal information of favorable mineralization elements, particularly in the Luotuowaizi area. The method demonstrated a higher spatial coverage rate with mineral points and a more vital ore-indicating ability. Specifically, the DE-WDCB method identified anomalies with a mean accuracy of 63.57% (p < 0.05, 95% CI: 47.64%–79.50%), compared to 50.53% for traditional methods. In conclusion, in regions with a complex topography and watershed differences, the DE-WDCB method effectively reduces local geochemical background interference, accurately identifies low and weak geochemical anomalies, and better reflects the actual distribution of elements. This makes it a significantly advantageous method for geochemical anomaly extraction, delineating higher-confidence exploration targets in the Sandaowan–Luotuowaizi area in the east and the triangular area between Duobaoshan, Yubaoshan, Sankuanggou, and the midstream highlands of the Guanbird River in the west. Full article

(This article belongs to the Section Mineral Exploration Methods and Applications)

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14 pages, 4666 KiB

Open AccessArticle

Impact of Humidity and Freeze–Thaw Cycles on the Disintegration Rate of Coal Gangue in Cold and Arid Regions: A Case Study from Inner Mongolia, China

by Chuangang Gong and Liya Yang

Minerals 2024, 14(9), 911; https://doi.org/10.3390/min14090911 - 5 Sep 2024

Abstract

Coal extraction in China is increasingly moving towards colder regions such as Xinjiang and Inner Mongolia. However, these mines face land restoration challenges due to a scarcity of fertile topsoil. This study explores the potential of coal gangue, a mining byproduct, as a [...] Read more.

Coal extraction in China is increasingly moving towards colder regions such as Xinjiang and Inner Mongolia. However, these mines face land restoration challenges due to a scarcity of fertile topsoil. This study explores the potential of coal gangue, a mining byproduct, as a viable substitute for topsoil. The study examines the effects of humidity fluctuations and freeze–thaw cycles, both individually and in combination, on the weathering disintegration of coal gangue. Coal gangue samples were subjected to controlled laboratory conditions simulating environmental factors. Fourteen interventions were analyzed, and the findings indicated that the combined application of humidity and freeze–thaw cycles significantly accelerated the disintegration process, outperforming the individual interventions. In addition, it was found that significant temperature variations caused the moisture and salts within the gangue to expand, which affected the rate of disintegration. The study showed that the rate of weathering disintegration was significantly higher in conditions of saturated humidity–freeze–thaw cycles compared to unsaturated humidity conditions. This highlights the essential role of ice crystals in accelerating the weathering process during temperature fluctuations. This study highlights the importance of humidity over temperature in the weathering and disintegration of coal gangue. It also suggests that freeze–thaw cycles can enhance this process. The study provides valuable insights for the management and utilization of coal gangue in cold and arid regions. Full article

(This article belongs to the Section Clays and Engineered Mineral Materials)

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20 pages, 9556 KiB

Open AccessArticle

Investigating the Orogenic Evolution of the Wushan–Shangdan Ocean in the Qinling–Qilian Conjunction Zone: Insights from the Early Devonian Tailu Pluton

by Hao Lin, Zuochen Li, Xianzhi Pei, Ruibao Li, Hai Zhou, Meng Wang, Shaowei Zhao, Li Qin and Mao Wang

Minerals 2024, 14(9), 910; https://doi.org/10.3390/min14090910 - 5 Sep 2024

Abstract

The main ocean–continent transformation stage of the Qinling and Qilian conjunction zone happened in the Early Paleozoic with the occurrence of a lot of subduction–collision–related magmatic rocks. However, there is still considerable controversy over the duration of the subduction–collision orogeny process of the [...] Read more.

The main ocean–continent transformation stage of the Qinling and Qilian conjunction zone happened in the Early Paleozoic with the occurrence of a lot of subduction–collision–related magmatic rocks. However, there is still considerable controversy over the duration of the subduction–collision orogeny process of the Proto-Tethys Ocean, here termed as the Wushan–Shangdan Ocean. We provide geochronological, geochemical, and Lu-Hf isotopic data for typical Early Devonian igneous rocks there, named Tailu pluton. The Tailu pluton at 410 Ma comprised K-rich, calc-alkaline, metaluminous A-type granite with low Y/Nb ratios (0.85 to 1.35) and A/CNK values (0.90 to 1.01); with high SiO₂ contents (65.44 to 74.46 wt%), Mg^# values (39.2 to 50.7), and zircon saturation temperatures (745 to 846 °C); and with negative ε_Hf (t) values (−8.0 to −1.9); therefore, they resulted from the partial melting of the ancient felsic lower crust accompanied by the incorporation of mantle-derived material during the intraplate magmatism process. Research on Tailu pluton has provided more sufficient evidence for the evolution process of the Qinling–Qilian conjunction zone in the Early Paleozoic, associated with evolution of the Wushan–Shangdan Ocean, the northern part of the Proto-Tethys Ocean. Full article

(This article belongs to the Section Mineral Geochemistry and Geochronology)

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18 pages, 4260 KiB

Open AccessArticle

Metallogenic Chronology and Prospecting Indication of Tiechanghe Granite and Polymetallic Molybdenum Mineralization Types in Jiulong Area, Western Sichuan, China

by Shuang Yang, Hongqi Tan, Zhongquan Li, Junliang Hu, Xinyan Wang and Daming Liu

Minerals 2024, 14(9), 909; https://doi.org/10.3390/min14090909 - 5 Sep 2024

Abstract

The Songpan–Ganzi Orogenic Belt (SGOB) is bounded by the South China, North China, and Qiangtang blocks and forms the eastern margin of the Tibetan Plateau. The Tiechanghe Granite is located at the junction of the southeast margin of the SGOB and the western [...] Read more.

The Songpan–Ganzi Orogenic Belt (SGOB) is bounded by the South China, North China, and Qiangtang blocks and forms the eastern margin of the Tibetan Plateau. The Tiechanghe Granite is located at the junction of the southeast margin of the SGOB and the western margin of the Yangtze Block. To elucidate the genetic relationship between the Tiechanghe Granite and the surrounding molybdenum deposits in Western Sichuan, in this study, we conducted zircon U-Pb and molybdenite Re-Os isotopic dating. The results indicate that the Tiechanghe Granite predominantly consists of monzogranite, with minor occurrences of syenogranite, while the molybdenum deposits are mainly found in skarn and quartz veins. The laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) zircon U-Pb ages of the Tiechanghe Granite range from 162.9 ± 0.7 Ma (MSWD = 0.31, n = 25) to 163.4 ± 0.6 Ma (MSWD = 0.85, n = 26), and the LA-ICP-MS zircon U-Pb age of the pegmatite veins is 164.1 ± 0.9 Ma (MSWD = 1.3, n = 19). These ages are consistent with the weighted average Re-Os age of the Ziershi molybdenite (160.3 ± 1.6 Ma, n = 2) within the error margins. These findings and previously obtained magmatic and metallogenic ages for the region suggest that a magmatic and mineralization event involving granite, molybdenum, tungsten, and copper occurred at around 162–164 Ma in the study area. This discovery broadens the exploration perspective for mineral resources in the Jiulong area of Western Sichuan and the entirety of Western Sichuan. Full article

(This article belongs to the Section Mineral Geochemistry and Geochronology)

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35 pages, 18094 KiB

Open AccessArticle

Multi-Phase Dolomitization in the Jurassic Paleo-Oil Reservoir Zone, Qiangtang Basin (SW China): Implications for Reservoir Development

by Ruilin Hao, Liyin Pan, Nana Mu, Xi Li, Xiaodong Fu, Shaoyun Xiong, Siqi Liu, Jianfeng Zheng, Min She and Axel Munnecke

Minerals 2024, 14(9), 908; https://doi.org/10.3390/min14090908 - 5 Sep 2024

Abstract

The age and dolomitization processes in the Paleo-oil reservoir zone, which is composed of massive dolostones found in the Qiangtang Basin (SW China), are still debated. In this research, the Long’eni-Geluguanna Area was selected. Macroscopic information, thin sections, and geochemical methods were used [...] Read more.

The age and dolomitization processes in the Paleo-oil reservoir zone, which is composed of massive dolostones found in the Qiangtang Basin (SW China), are still debated. In this research, the Long’eni-Geluguanna Area was selected. Macroscopic information, thin sections, and geochemical methods were used to investigate the dolomitization characteristics and the processes that controlled dolomitization. Five types of replacive dolomites and two types of dolomite cement were observed. Some of the dolomites displayed ghosts of primary sedimentary structures. Saddle dolomites were prevalent, occurring in the interparticle and moldic pores of the limestone which should have been filled at an early diagenetic stage. Ten microfacies types were identified. The foraminifera assemblage provides evidence that the studied interval is of Early Jurassic age. The δ¹³C values are similar to the contemporaneous seawater signature. The REE+Y patterns of limestones and dolostones exhibit similarities to that of seawater. The mean Na and Sr values are comparable to those of other near-normal seawater dolomites. The δ¹⁸O values of all lithologies are markedly depleted. The dolomitization started penecontemporaneously, with deposition. A general sand shoal setting with patch reefs developed. The dolomitizing fluids, near-normal seawater, was probably formed by slight evaporation on top of the shoal. Saddle dolomites in the interparticle and moldic pores might indicate hydrothermal activity, which also caused the recrystallization of some pre-existing dolomites. The recrystallization might have slightly increased the crystal size, demolished the ghost structures, formed saddle dolomites, and altered the REE+Y patterns. The recrystallization extent diminished with increasing distance from the fluids-providing fracture. Furthermore, the existence of protected areas within the sand shoal settings could enhance the vertical and horizontal heterogeneity of dolostone reservoirs. Full article

(This article belongs to the Special Issue Dolomitization, Recrystallization, and Cementation in Carbonate Sedimentary Rocks)

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19 pages, 19626 KiB

Open AccessArticle

The Fluid Evolution in the Skarn Stages of the Baoshan Skarn Cu-Polymetallic Deposit, South China

by Ping Zheng, Ke Chen, Jun-Ke Zhang, Zhong-Fa Liu, Yong-Shun Li and Ming-Peng He

Minerals 2024, 14(9), 907; https://doi.org/10.3390/min14090907 - 5 Sep 2024

Abstract

Baoshan is a world-class skarn Cu-polymetallic deposit located at the junction of the Nanling and Qin-Hang metallogenic belts in China. While there has been extensive research on the mineralogy and geochemistry of skarn deposits, studies on the fluid characteristics and evolutionary history from [...] Read more.

Baoshan is a world-class skarn Cu-polymetallic deposit located at the junction of the Nanling and Qin-Hang metallogenic belts in China. While there has been extensive research on the mineralogy and geochemistry of skarn deposits, studies on the fluid characteristics and evolutionary history from the early to late skarn stages in such deposits are still limited. In this study, we analyzed garnet and pyroxene from the early skarn stage and scheelite from the late skarn stage of the Baoshan deposit. We distinguished two generations of garnet (Grt1 and Grt2), one generation of pyroxene, and three generations of scheelite (Sch I, Sch II, and Sch III) on the basis of mineral assemblages and microscopic characteristics. Grt1 appears coarse-grained, and Grt2 cuts through Grt1 as veinlets. In Grt1, the andradite end-member increases from the core to the rim, while the grossular portion decreases (Ad_35–36Gr_59–61Sp_3–4 to Ad_59–61Gr_36–37Sp_2–3), and in Grt2, the andradite end-member significantly increases (Ad_41–73Gr_25–55Sp_2–3). Grt1 and Grt2 have similar trace element compositions, with enrichment in Zr and depletion in Nb and Hf, depletion in LREE, enrichment in HREE, and weak negative Eu anomalies. Pyroxene coexists with Grt1 and is similarly cut by Grt2, with its composition mainly being diopside (Di_82–99Hd_0.6–15Jo_0–3.2). Sch I and Sch II appear as anhedral to subhedral grains, while Sch III is predominantly found in veinlets. In Sch I and Sch II, most REEs enter the scheelite lattice via the Na-REE coupled substitution mechanism, with a smaller portion substituting Ca vacancies. In Sch III, the substitution mechanism involving Ca site vacancies may dominate. During the early skarn stage, the oxygen fugacity of the fluid gradually decreased from Grt1 and pyroxene to Grt2. In the late skarn stage, fluid oxygen fugacity remains stable from Sch I and Sch II to Sch III in shallow parts but significantly decreases in deeper parts. The garnet and pyroxene from the Baoshan deposit align with typical skarn Cu deposit compositions, while scheelite in the late skarn stage shows Sch I, Sch II, and shallow Sch III as skarn-type and deep Sch III as vein-type scheelite. Early skarn stage fluids were weakly acidic. Sch I, Sch II, and Sch III originated from fluids related to the Baoshan granite porphyry, with Sch III also showing evidence of water–rock interaction. This study reconstructed the fluid evolution history from the early to late skarn stages at the Baoshan deposit, providing insights into the ore-forming processes of other skarn deposits. Full article

(This article belongs to the Special Issue Geology, Geochemistry, Genesis, Modeling, Structure and Exploration of Copper Polymetallic Deposits)

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13 pages, 1700 KiB

Open AccessArticle

Investigation of the Flotation of an Ore Containing Bastnaesite and Monazite: Kinetic Study and Process Flowsheet Simulation

by Claude Bazin and Jean-François Boulanger

Minerals 2024, 14(9), 906; https://doi.org/10.3390/min14090906 - 4 Sep 2024

Abstract

Laboratory flotation tests carried out using an ore sample containing Rare Earth Elements (REEs) present as monazite and bastnaesite show that the flotation of monazite is slower and yielded lower recovery than that of bastnaesite. Results show that when studying the performances of [...] Read more.

Laboratory flotation tests carried out using an ore sample containing Rare Earth Elements (REEs) present as monazite and bastnaesite show that the flotation of monazite is slower and yielded lower recovery than that of bastnaesite. Results show that when studying the performances of a concentration process for an REE ore, it is essential to not look only at the behavior of the individual REEs but to convert elemental assays into mineral assays to obtain the mineral’s actual response to the concentration process. The results of the laboratory flotation tests are used to calibrate a flotation simulator applied to study different circuit configurations for the concentration of the REE minerals. Indeed, it is shown that for the studied ore, two cleaning stages of a rougher concentrate are sufficient to produce a concentrate with a Total Rare Earth Oxide (TREO) grade above 40%, which is acceptable for the subsequent hydrometallurgical process. The simulation also shows that it may be feasible, if required for the hydrometallurgy step, to separate bastnaesite and monazite by taking advantage of the different flotation kinetics of the two minerals. Full article

(This article belongs to the Special Issue Rare Earth Elements: Occurrence, Exploration, Alternate Resources, Extraction Techniques, Chemical Characterization and Recycling)

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17 pages, 4161 KiB

Open AccessArticle

Flotation Tailings from Cu-Au Mining (Bor, Serbia) as a Potential Secondary Raw Material for Valuable Metals Recovery

by Vanja Trifunović, Ljiljana Avramović, Dragana Božić, Marija Jonović, Dragan Šabaz and Dejan Bugarin

Minerals 2024, 14(9), 905; https://doi.org/10.3390/min14090905 - 3 Sep 2024

Abstract

The increased exploitation of ores leads to the generation of mining waste, which has a negative impact on the environment and human health. For this reason, it is necessary to take care of it in an adequate way by applying some of the [...] Read more.

The increased exploitation of ores leads to the generation of mining waste, which has a negative impact on the environment and human health. For this reason, it is necessary to take care of it in an adequate way by applying some of the possible treatments. In addition to protecting the environment by applying appropriate treatment, there is also the possibility of making a profit by valorizing useful elements from mining waste. In order to choose the most adequate treatment, it is necessary to perform the characterization of mining waste. This paper contains a detailed characterization of the flotation tailings deposited at the Old Flotation Tailings in eastern Serbia, originating from copper ore processing. Characterization includes physico-chemical analysis, polarizing microscope analysis, X-ray Diffraction analysis (XRD) and Scanning Electron Microscopy with Energy Dispersive Spectroscopy (SEM-EDS) analysis analysis. The obtained results indicate that the investigated flotation tailings can be used as a secondary raw material for metal recovery, in this case primarily copper (whose content is about 0.24%), gold (with a content of about 0.43 ppm) and silver (with a content of about 1.7 ppm). Considering that the content of valuable elements is quite low, it is suggested to apply hydrometallurgical treatment for their recovery. Full article

(This article belongs to the Special Issue Metallurgical Solid Waste: Mineralogy, Chemistry and Application/Treatment, 2nd Edition)

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16 pages, 10492 KiB

Open AccessArticle

Boron Enrichment in Salinized Lacustrine Organic-Rich Shale of the Paleogene Biyang Depression, East China: Occurrence and Geological Controlling Factors

by Yu Song, Paerzhana Paerhati, Shilin Xu, Bo Gao, Shu Jiang, Shuifu Li, Yuchen Wang and Hecun Lv

Minerals 2024, 14(9), 904; https://doi.org/10.3390/min14090904 - 3 Sep 2024

Abstract

Although boron (B) is widely applied as a paleosalinity indicator for ancient lakes, the occurrence and geological controls of B enrichment in salinized lacustrine organic-rich shale (SLORS) are poorly understood. This study addresses this issue by comparing the mineral and element compositions of [...] Read more.

Although boron (B) is widely applied as a paleosalinity indicator for ancient lakes, the occurrence and geological controls of B enrichment in salinized lacustrine organic-rich shale (SLORS) are poorly understood. This study addresses this issue by comparing the mineral and element compositions of high-boron shale (HBS) and low-boron shale (LBS) from the Paleogene Biyang Depression, using integrated XRD, XRF, and ICP-MS analyses. The mineral composition of HBS is dominated by illite, whereas LBS primarily consists of albite; both are of detrital origin. Compared to the element composition of UCC, HBS is extremely enriched in Mo and W, whereas LBS is extremely enriched in W and U. Boron is positively correlated with Al₂O₃ and negatively correlated with Na₂O, suggesting that B primarily occurs in illite. An enhanced extent of chemical weathering prevailed during the deposition of HBS, providing a greater supply of illite to the basin. Higher pH levels and greater reduction during HBS deposition encouraged illite absorption of B, ultimately leading to B enrichment in shale. Our findings suggest that pH and redox conditions, as well as the mineral compositions of shale, should be fully considered during the application of B and related ratios as paleosalinity indicators. Full article

(This article belongs to the Section Mineral Geochemistry and Geochronology)

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11 pages, 17876 KiB

Open AccessArticle

Sediment-Hosted Rare-Earth Elements Mineralization from the Dian-Qian District, Southwest China: Mineralogy and Mode of Occurrence

by Bo Hui, Daxing Gong, Lu Xu, Yang Lai, Jianhua Qin, Ying Xu, Wei Yang and Haitao Lin

Minerals 2024, 14(9), 903; https://doi.org/10.3390/min14090903 - 3 Sep 2024

Abstract

The Xuanwei Formation’s claystones in the Dian-Qian District of Southwest China are rich in rare-earth elements (REEs), suggesting their potential as a source of medium and heavy rare earths. However, the REE content in these rocks is lower than other types of rare-earth [...] Read more.

The Xuanwei Formation’s claystones in the Dian-Qian District of Southwest China are rich in rare-earth elements (REEs), suggesting their potential as a source of medium and heavy rare earths. However, the REE content in these rocks is lower than other types of rare-earth deposits, and the interrelationship among clay minerals is intricate. There is no direct evidence indicating the mineralization of REEs, limiting their beneficiation and extraction. The objective of this study is the characterization of REE distribution in the Dian-Qian District. The sedimentary rocks in this district are mainly composed of kaolinite, boehmite, quartz, rutile, and pyrite. The results of continuous chemical extraction of REE-rich claystone and transmission electron microscope (TEM) observations have confirmed that REEs occurred as florencite in the rocks, and that the ion-absorption state makes only a negligible contribution to the REE content. A close relationship between florencite and kaolinite makes traditional mineral processing operations very difficult. Combined with the properties of kaolinite, roasting-acid leaching was the efficacious approach for rare-earth resources extracted from the rare earth-rich clay rocks of the Xuanwei Formation. Full article

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16 pages, 3363 KiB

Open AccessArticle

Open-Circuit Technology of Zinc Oxide Ore Flotation with Ternary Collector and Its Adsorption Characteristics on Smithsonite Surface

by Zhiwei Li, Qicheng Feng, Qian Zhang and Shuming Wen

Minerals 2024, 14(9), 902; https://doi.org/10.3390/min14090902 - 2 Sep 2024

Abstract

The sulfidization-amine flotation method is commonly used for the beneficiation of zinc oxide ores. Lanping zinc oxide ores contains 8.40% zinc, with the main mineral being smithsonite; additionally, they have a high mud content. Conventional sulfidization–ammonium flotation presents a low flotation index and [...] Read more.

The sulfidization-amine flotation method is commonly used for the beneficiation of zinc oxide ores. Lanping zinc oxide ores contains 8.40% zinc, with the main mineral being smithsonite; additionally, they have a high mud content. Conventional sulfidization–ammonium flotation presents a low flotation index and unsatisfactory flotation froth. A new open-circuit technology is employed to treat Lanping zinc oxide ores, where Na₂S, KG-248, and dodecyl amine + sodium isoamyl xanthate + ammonium dibutyl dithiophosphate are used as the regulator, depressant, and ternary collector, respectively. Consequently, the flotation indices for the zinc grade and recovery are 28.71% and 86.24%, respectively, and the flotation froth becomes more stable. Subsequently, the flotation behavior and adsorption mechanism of smithsonite with a ternary collector are investigated. The flotation recovery of smithsonite increases to 94.40% after treatment with the ternary collector. Surface-analysis results indicate that the ternary collector can synergistically adsorb onto the sulfidized smithsonite surface to enhance its hydrophobicity, thus increasing the floatability of smithsonite. Meanwhile, the total consumption of the collector in the ternary-collector system is lower than that in the binary- or unitary-collector system. Full article

(This article belongs to the Special Issue Advances in Flotation of Copper, Lead and Zinc Minerals)

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