Editor’s Choice Articles

Micro-nanobubbles have emerged as a transformative technology in mineral flotation, offering superior performance in the recovery of fine-grained minerals. Conventional flotation processes often struggle with low recovery rates due to inefficient particle–bubble interactions and the formation of slimes, which increase pulp viscosity and reduce selectivity. Micro-nanobubbles, characterized by their smaller size, larger specific surface area, and high stability, overcome these limitations by enhancing collision efficiency, promoting particle aggregation through the “bubble bridge” effect, and improving flotation recovery rates and concentrate quality. This review systematically examines the generation mechanisms of micro-nanobubbles, critically appraises their laboratory and industrial applications through specific case studies, and elucidates their fundamental roles in enhancing fine-grained mineral recovery by increasing collision-attachment efficiency and promoting hydrophobic aggregation. Additionally, the study highlights real-world application cases and discusses future directions for optimizing micro-nanobubbles flotation technology through equipment improvements, process integration, and synergies with emerging techniques. The findings underscore the potential of micro-nanobubbles to revolutionize mineral processing by increasing recovery efficiency, reducing reagent usage, and enhancing sustainability. Full article

Red mud, a strongly alkaline solid waste generated during alumina production, contains valuable metals including aluminum, iron, titanium, and others. Efficient extraction of these metals is of great significance for promoting circular economy development and regional ecological conservation. This paper proposes a stepwise extraction process involving alkali roasting-water leaching to separate Al from Fe and Ti, hydrochloric acid leaching to separate Fe from Ti, and sulfuric acid leaching to extract Ti. Bayer red mud from Guangxi, China was used as the raw material, and the effects of process parameters on the stepwise leaching of Al, Fe, and Ti were systematically investigated. The overall leaching results indicated that the total leaching rates of Al, Fe, and Ti were 99.61%, 99.02%, and 92.75%, respectively. Through comparative analysis of the chemical composition, phase composition, and micromorphology of the raw red mud, roasted clinker, and leaching residues, the stepwise leaching mechanisms of Al, Fe, and Ti were elucidated. Furthermore, the second-stage acid leachate was hydrolyzed, and the H₂TiO₃ content in the obtained hydrolyzate reached 89.43%, approximately 12 times that of the titanium component in the raw red mud. The Ti hydrolysis recovery rate was 90.41%, and the total Ti recovery rate was 78.65%. Overall, the process enables stepwise extraction of Al, Fe, and Ti, along with the enrichment and recovery of titanium resources, providing an effective reference route for the technical chain of resource utilization of valuable components in red mud. Full article

Esterification, the reaction between carboxylic acids and alcohols that produces esters and water, plays a vital role in many industries, especially in biodiesel and pharmaceutical manufacturing. Traditional methods using homogeneous mineral acids pose environmental issues, prompting the search for sustainable alternatives—solid acid catalysts. Zeolites offer unique structural advantages, including shape selectivity and adjustable acidity, which improve reaction efficiency and reduce waste. This review provides a detailed examination of how zeolite topology—particularly pore structure and connectivity—influences the kinetics of long-chain fatty acid (LCFA) esterification. It investigates the optimization of acid sites via modifications to the silicon-to-aluminum ratio (Si/Al), ion exchange, and pore engineering to improve mass transfer. The study investigates key reaction mechanisms, specifically the Langmuir–Hinshelwood (LH) and Eley–Rideal (ER) models, to address issues such as mass-transfer limitations and water inhibition. The paper highlights recent advances in sustainable catalyst design, such as hierarchical zeolites and membrane-integrated reactors, for converting biomass-derived feedstocks into valuable esters. It also discusses current research challenges and suggests future directions, including the use of 3D-printed monoliths and machine learning integration, to develop next-generation, eco-friendly zeolite catalysts. Full article

Magnetic and electromagnetic techniques have been applied successfully to mineral exploration discovery. Both techniques rely on inferring the distribution of subsurface physical properties based on ground, airborne or borehole field measurements. Consequently, interpretation methods relating field measurements to underground physical properties are key to geophysical method success. Over the last 15 years, with the evolution of computer processing techniques, interpretation methods have matured and have seen numerous developments, from approximate interpretation to 3D inversion. The recent study of the scientific literature on magnetic and electromagnetic interpretation followed by an analysis of the distribution of the publication of these studies publication (and the citation numbers quoted) outline the research on these topics. The majority of studies are on electromagnetism, with an emphasis on numerical modeling, approximations, superparamagnetism, and induced polarization. In magnetics, the most popular studies were on remanence magnetization inversion and Euler deconvolution. Studies applicable to both methods involved 3D inversion, artificial intelligence, and open-source software. The number of citations reveals a different picture than the number of publications, where the same categories are present but magnetic study citations dominate, indicating in general a time lag of 10 years. The results of this review may help direct future research in these areas. Full article

Naomaohu coal from the Santanghu Basin, Xinjiang, is characterized by anomalously high Na and Ca contents, which strongly affect its gasification behavior and slagging tendency. However, the genetic linkage between geological alkali enrichment and their transformation during thermal processes remains insufficiently constrained. In this study, an integrated investigation combining coal seam profile analysis, coal petrography, mineralogical characterization, and fixed-bed gasification experiments was conducted to elucidate the enrichment mechanisms and transformation pathways of alkali and alkaline earth metals (AAEMs). A total of forty six samples were collected along a vertical seam profile to determine the depositional control of alkali and alkaline earth metals (AAEMs), and seven representative samples were further subjected to pressurized fixed-bed gasification. Alkali migration and mineral phase evolution were systematically analyzed using XRD, XRF, and SEM-EDS. The results indicate that Na enrichment is mainly controlled by groundwater infiltration and weak paleoweathering, while Ca accumulation reflects deposition in humid, Ca-rich mire environments. During gasification, Na volatilizes and recondenses as Na-feldspars (NaAlSi₂O₆) and NaCl, whereas Ca decomposes into gehlenite (Ca₂Al₂SiO₇) and brownmillerite (Ca₂AlFeO₅). The formation of these low-melting Na–Al–Si phases and Ca–Fe–Al phases dominate the ash fusion and slagging behavior. This study establishes a coupled geological–thermal transformation model for AAEMs in high-Na coal, providing mechanistic insight into mineralogical inheritance and offering guidance for mitigating alkali-induced slagging during gasification. Full article

Routine chemical assays, which are more readily available than direct mineralogical analyses, offer a rapid and cost-efficient approach of estimating mineral grades for geometallurgical modelling. This paper addresses the prediction of ore minerology from chemical assays for lithium-bearing pegmatites by implementing and comparing two element-to-mineral conversion (EMC) approaches: (1) mass balance techniques using two calculation variants and (2) machine learning methods (MLM). Both routines of the mass balance approach achieved satisfactory R² values exceeding 0.8, although calculation routine 1 was unable to automatically differentiate between the two lithium-bearing phases (spodumene and cookeite). Of the eight algorithms applied for the MLM approach, the top three performing models achieved R² values greater than 0.6 for both training and testing datasets, with slightly lower error evaluation metrics compared to the mass balance approach. Based on data accuracy requirements across the Mine Value Chain, the mass balance approach is suitable for the feasibility and operational stages, while the MLM approach meets the minimum data accuracy requirements of the scoping and pre-feasibility stages. However, it should be noted that the mass balance approach is limited to deposits with simple mineral assemblages while the MLM approach can handle deposits with greater elemental overlap among minerals. Full article

This research investigates ten sediment cores extracted from Holocene deposits in Labu, northern Temburong District, Brunei Darussalam, to provide an initial inventory of the encountered peat-forming environments. Proximate, ultimate, and geochemical analyses were performed, along with mineralogical characterisations and ¹⁴C radiocarbon dating, as well as preliminary palaeontological and palynological examinations of the peat and underlying substrate layers. Localised organic deposits, termed “peat pockets”, were identified, with the oldest found to have begun accumulating under topogenous-mire conditions during the Middle Holocene. This coincides with the Mid-Holocene sea-level rise, which is thought to have peaked at 6000–4500 years BP. However, our data suggest that sea level may have continued rising until approximately 2500 years BP, peaking between 2500 and 1700 years BP, followed by delta progradation in Temburong. These “peat pockets” gradually coalesced into larger topogenous mires associated with estuarine environments. Over time, they became less influenced by marine conditions and increasingly shaped by a freshwater regime, resembling an upper delta system, similar to the present-day landscape observed in Temburong. It is proposed that these mires transitioned from a topogenous to an ombrogenous phase approximately 250 to 320 years BP, as inferred through forward age extrapolation based on a constant accumulation rate. The findings support the hypothesis of inland coastline migration during the Middle Holocene, followed by retraction due to deltaic progradation in the Late Holocene. These fluctuations align with well-established sea-level changes driven by climatic variability. Full article

The nitric acid leaching of antimony from stibnite using organic (tartaric and citric) acids as complexing agents was investigated. Tartaric acid has been found to be a more effective complexing agent, providing up to 90% antimony recovery, while citric acid achieves 54% only. SEM and X-ray diffraction analysis showed tartaric acid to prevent antimony hydrolysis, preserving unreacted stibnite in the residue, while Sb₄O₄(OH)₂(NO₃)₂ particles were formed in the system with citric acid. Kinetic calculations have revealed that the nitric acid leaching of antimony with the addition of tartaric acid is limited by internal diffusion (R² > 0.94), the activation energy is 62.5 kJ/mol, and the empirical reaction orders for tartaric and nitric acids are 2.3 and 2.7, respectively. These data are confirmed by morphological and phase analyses, the mechanisms of action of organic acids have been substantiated, and a generalized kinetic equation describing the nitric acid leaching of antimony with the addition of tartaric acid is proposed. Full article

The South Sakhalin mud volcano (Sakhalin Island, Russia) emits HCO₃-Cl/Na-Mg water, emanates CO₂ prevailing over CH₄ in the gas phase, and extrudes mud bearing five carbonate mineral species. The study focuses on the distribution, diversity, and origin of the carbonate minerals from the mud volcano (MV) ejecta, in terms of carbon cycle processes. The data presented include a synthesis of field observations, compositions of MV gases and waters, chemistry of carbonate minerals, as well as stable isotope geochemistry of MV waters (δ¹³C, δD, and δ¹⁸O) and carbonates (δ¹³C and δ¹⁸O). The sampled MV waters are isotopically heavy, with δ¹⁸O = +5.7‰ to +7.5‰ VSMOW, δD = −18.0‰ to −11.0‰ VSMOW, and ¹³C (δ¹³C_DIC = +6.9‰ to +8.1‰ VPDB). This composition may be due to the dilution of basinal water with dehydration water released during the diagenetic illitization of smectite. Carbonates in the sampled mud masses belong to three genetically different groups. Mg-rich siderite, (Fe_0.54–0.81Mg_0.04–0.30Ca_0.05–0.23Mn_0.00–0.08)CO₃, disseminated in abundance throughout the mud masses, coexists with common calcite and sporadic ankerite. The trace-element chemistry of Mg-siderite, as well as the oxygen (δ¹⁸O = +34.4‰ to +36.8‰ VSMOW) and carbon (δ¹³C = −1.3‰ to +0.6‰ VPDB) isotopic signatures, confirms its authigenic origin. Siderite formed during early diagenesis of the Upper Cretaceous sandy and clayey marine sediments mobilized by mud volcanism in the area. Another assemblage, composed of dawsonite, siderite, and vein calcite (±kaolinite), represents altered arkose sandstones found as few fragments in the mud. This assemblage may be a marker of later CO₂ flooding into the sandstone aquifer in the geological past. The trace-element chemistry, particular morphology, and heavy C (δ¹³C = +5.5‰ to +7.0‰ VPDB) and O (δ¹⁸O = +39.1‰ to +39.5‰ VSMOW) isotope compositions indicate that aragonite is the only carbonate species that is related to the current MV activity. It crystallized in a shallow reservoir and was maintained by CO₂ released from rapidly ascending liquefied mud and HCO₃-Cl/Na-Mg-type of MV waters. Full article

The six platinum group elements (PGE) are among the rarest elements in the upper continental crust of the earth. Higher values of PGE have been detected in the upper mantle and in chondrite meteorites. The PGE are siderophile and chalcophile elements and are divided into the following: (1) the Ir subgroup (IPGE) = Os, Ir, and Ru and (2) the Pd subgroup (PPGE) = Rh, Pt, and Pd. The IPGE are more refractory and less chalcophile than the PPGE. High concentrations of PGE led, in rare cases, to the formation of mineral deposits. The PGE are carried in discrete phases, the platinum group minerals (PGM), and are included as trace elements into the structure of base metal sulphides (BM), such as pentlandite, chalcopyrite, pyrite, and pyrrhotite. Similarly to PGE, the PGM are also divided into two main groups, i.e., IPGM composed of Os, Ir, and Ru and PPGM containing Rh, Pt, and Pd. The PGM occur both in mafic and ultramafic rocks and are mainly hosted in stratiform reefs, sulphide-rich lenses, and placer deposits. Presently, there are only 169 valid PGM that represent about 2.7% of all 6176 minerals discovered so far. However, 496 PGM are listed among the valid species that have not yet been officially accepted, while a further 641 are considered as invalid or discredited species. The main reason for the incomplete characterization of PGM resides in their mode of occurrence, i.e., as grains in composite aggregates of a few microns in size, which makes it difficult to determine their crystallography. Among the PGM officially accepted by the IMA, only 13 (8%) were discovered before 1958, the year when the IMA was established. The highest number of PGM was discovered between 1970 and 1979, and 99 PGM have been accepted from 1980 until now. Of the 169 PGM accepted by the IMA, 44% are named in honour of a person, typically a scientist or geologist, and 31% are named after their discovery localities. The nomenclature of 25% of the PGM is based on their chemical composition and/or their physical properties. PGM have been discovered in 25 countries throughout the world, with 64 from Russia, 17 from Canada and South Africa (each), 15 from China, 12 from the USA, 8 from Brazil, 6 from Japan, 5 from Congo, 3 from Finland and Germany (each), 2 from the Dominican Republic, Greenland, Malaysia, and Papua New Guinea each, and only 1 from Argentine, Australia, Bulgaria, Colombia, Czech Republic, England, Ethiopia, Guyana, Mexico, Serbia, and Tanzania each. Most PGM phases contain Pd (82 phases, 48% of all accepted PGM), followed, in decreasing order of abundances, by those of Pt 35 phases (21%), Rh 23 phases (14%), Ir 18 phases (11%), Ru 7 phases (4%), and Os 4 phases (2%). The six PGE forming the PGM are bonded to other elements such as Fe, Ni, Cu, S, As, Te, Bi, Sb, Se, Sn, Hg, Ag, Zn, Si, Pb, Ge, In, Mo, and O. Thirty-two percent of the 169 valid PGM crystallize in the cubic system, 17% are orthorhombic, 16% hexagonal, 14% tetragonal, 11% trigonal, 3% monoclinic, and only 1% triclinic. Some PGM are members of a solid-solution series, which may be complete or contain a miscibility gap, providing information concerning the chemical and physical environment in which the mineral was formed. The refractory IPGM precipitate principally in primitive, high-temperature, mantle-hosted rocks such as podiform and layered chromitites. Being more chalcophile, PPGE are preferentially collected and concentrated in an immiscible sulphide liquid, and, under appropriate conditions, the PPGM can precipitate in a thermal range of about 900–300 °C in the presence of fluids and a progressive increase of oxygen fugacity (fO₂). Thus, a great number of Pt and Pd minerals have been described in Ni-Cu sulphide deposits. Two main genetic models have been proposed for the formation of PGM nuggets: (1) Detrital PGM represent magmatic grains that were mechanically liberated from their primary source by weathering and erosion with or without minor alteration processes, and (2) PGM reprecipitated in the supergene environment through a complex process that comprises solubility, the leaching of PGE from the primary PGM, and variation in Eh-pH and microbial activity. These two models do not exclude each other, and alluvial deposits may contain contributions from both processes. Full article

In multi-phase tectonic activity areas, complex stratigraphic uplift-subsidence cycles lead to multi-phase, superimposed diagenesis. This obscures the mechanisms of reservoir property evolution and makes predicting diagenetic sweet spots difficult. This study investigates the low-permeability clastic reservoirs in the Mesozoic of the Tanhai area, Jiyang Depression. Integrating thin-section petrography, scanning electron microscopy (SEM), X-ray diffraction (XRD), high-pressure mercury injection, and burial history analysis, it reveals multi-phase diagenetic characteristics from a tectonic perspective and quantifies pore structure modification mechanisms. Results show the reservoirs underwent strong compaction and multi-phase carbonate-dominated cementation. Dissolution is further distinguished into meteoric water, organic acid, and volcanic material-related alkaline dissolution. Pore-throat evolution indicates that compaction and cementation shift pores towards micropores (<0.1 µm), while meteoric and alkaline dissolution enlarge mesopores (0.1–10 µm) crucial for permeability. Reservoir diagenesis is divided into five tectonic—diagenetic stages. A quantitative model identifies two diagenetic sweet spot types: (1) zones near unconformities intensely leached by meteoric water, and (2) relatively shallow intervals affected by alkaline dissolution related to volcanic rocks under deep burial. This study establishes a tectonic—diagenetic—pore structure framework. It provides a basis for predicting reservoir sweet spots in analogous multi-phase tectonic settings. Full article

The Hadamengou gold deposit, hosted in the Precambrian metamorphic basement, is a super-large gold deposit occurring along the northern margin of the North China Craton. Despite extensive investigation, the genesis of the gold mineralization is poorly understood and remains highly debated. This study integrates a comprehensive dataset, including fluid inclusion microthermometry and C-H-O-S-Pb isotopes, to better constrain the genesis and ore-forming mechanism of the deposit. Hydrothermal mineralization can be divided into pyrite–potassium feldspar–quartz (Stage I), quartz–gold–pyrite–molybdenite (Stage II), quartz–gold–polymetallic sulfide (Stage III), and quartz–carbonate stages (Stage IV). Four types of primary fluid inclusions are identified, including pure CO₂-type, composite CO₂-H₂O-type, aqueous-type, and solid-daughter mineral-bearing-type inclusions. Microthermometric and compositional data reveal that the fluids were mesothermal to hypothermal, H₂O-dominated, and CO₂-rich fluids containing significant N₂ and low-to-moderate salinity, indicative of a magmatic–hydrothermal origin. Fluid inclusion assemblages further imply that the ore-forming fluids underwent fluid immiscibility, causing CO₂ effusion and significant changes in physicochemical conditions that destabilized gold bisulfide complexes. The hydrogen–oxygen isotopic compositions, moreover, support a dominant magmatic water source, with increasing meteoric water input during later stages. The carbon–oxygen isotopes are also consistent with a magmatic carbon source. Sulfur and lead isotopes collectively imply that ore-forming materials were derived from a hybrid crust–mantle magmatic reservoir, with minor contribution from the country rocks. By synthesizing temporal–spatial relationships between magmatic activity and ore formation, and the regional tectonic evolution, we suggest that the Hadamengou is an intrusion-related magmatic–hydrothermal lode gold deposit. It is genetically associated with multi-stage magmatism induced by crust–mantle interaction, which developed within the extensional tectonic regimes. Full article

This study focuses on the mineralogy and mineral chemistry of the accessory minerals occurring in the Kastoria pluton situated in NW Greece, which intrudes the Pelagonian nappe having crystallized during the Late Paleozoic (~300 Ma). The pluton consists of porphyritic granite (GR) that hosts mafic microgranular enclaves (MME) of monzonitic composition. Both lithologies contain quartz, microcline, plagioclase, biotite, secondary white mica, hornblende, and actinolite along with accessory minerals including titanite, epidote, allanite, apatite, zircon, and magnetite. Compared to the granite, the enclaves are richer in biotite, amphibole, and plagioclase but poorer in quartz and microcline. Mineral chemistry indicates a calc–alkaline affinity, consistent with the observed magmatic trends. Crystallization pressure, estimated at 3 kbar from Al in a hornblende barometer, suggests emplacement at mid-crustal levels. During the Alpine deformation, the pluton underwent low-grade greenschist to amphibolite-facies metamorphism, which partially overprinted the primary mineral assemblages. Magmatic titanite and allanite crystals are well preserved, showing only recrystallization features. Metamorphism produced tiny titanite needles and epidote replacing primary minerals (plagioclase, amphibole, and biotite). Later, hydrothermal alteration produced another generation of secondary epidote. Only a couple of epidote crystals preserve potential magmatic relict characteristics (euhedral habit, zircon inclusions, positive Eu anomaly, and sharp contact with primary minerals). These results provide insights into both the primary magmatic features and the subsequent metamorphic modification of the I-type Kastoria pluton within the Pelagonian domain. Full article

Infrared spectroscopic analysis of palygorskite clay from the Dashkovskoye and Borshchevskoye deposits yielded key insights into the sedimentation conditions prevailing in the study area. In this paper, the composition, structure, and adsorption properties of smectite–palygorskite clays from the Steshevian sub-stage of the Lower Carboniferous (Russia) are investigated. The study applied X-ray diffraction, infrared spectroscopy, scanning electron microscopy, assessment of cation exchange capacity by adsorption of [Cu(trien)²⁺], assessment of Cs sorption, and particle size analysis. It is demonstrated that the Al–palygorskite of the Dashkovskoye deposit was formed by sedimentation from suspended matter in a shallow-water basin in the Steshevian sub-age, despite a different genesis (chemogenic in the case of the palygorskites, clastic/redeposited in the case of the smectites). The palygorskites of the Borschovskoye deposit have a complex terrigenous genesis and were formed from redeposited chemogenic Al–palygorskites transported into the basin from the surrounding region of the Dashkovskoye deposit. With increasing depth of the basin in the Steshevian sub-age, the volume of incoming palygorskite material decreases, and the proportion of smectite material increases. The Fe–palygorskites entered the Borschovskoye deposit due to the redeposition of sediments from soils upstream of water flows. All the studied clays have considerable adsorption properties (32–49 mg-eq/100 g) and can be used in various industries. Full article

There exists an east–west trending albitite (breccia) zone, approximately 400 km in length, closely related to gold mineralization, in Devonian strata in the South Qinling tectonic belt. The genesis and formation age of these albitite (breccia) are of great significance for understanding gold enrichment mechanisms and guiding future exploration. Past studies have mainly focused on the Fengxian–Taibai area in the western segment of the albitite (breccia) zone, whereas the eastern segment remains significantly understudied. In this study, a systematic field investigation, as well as petrology, geochemistry, and accessory-mineral geochronology studies were conducted on albitites and albitite breccias in the Shangnan area, the eastern segment of the albitite (breccia) zone. The results show that the albitites are interlayered with or occur as lenses within Devonian clastic rocks. The albitite breccias are mostly enclosed in albitite and Devonian strata, and the clasts within are subangular, uniform in type, and exhibit minimal displacement. Both albitites and albitite breccias exhibit similar trace-element characteristics and detrital zircon age spectra to those of Devonian clastic rocks. Abundant hydrothermal monazites with U–Pb ages ranging from 260 to 252 Ma are present in both albitites and albitite breccias but absent in Devonian clastic rocks. Collectively, these results indicate that the albitites in the Shangnan area are of hydrothermal metasomatic origin, while the albitite breccias record hydraulic fracturing and cementation, and both are products of the same fluid activity event in the Late Permian. We propose that albitite (breccia) zones in the South Qinling tectonic belt were formed under distinct tectonic settings during different evolution stages of the Late Paleozoic Mianlüe Ocean. Specifically, the albitites (breccias) in the Shangnan area are products of thorough metasomatism, local fracturing, and cementation of Devonian clastic rocks by mixed fluids, which ascended along the Fengzhen–Shanyang Fault coeval with the emplacement of magmatic rocks related to subduction of the Mianlüe Ocean. In contrast, the albitite breccias in the Fengxian–Taibai area are the result of fluid activity during the transition from regional compression to extension after the closure of the Mianlüe Ocean. Full article

Semi-autogenous (SAG) milling represents one of the most energy-intensive and variable stages of copper mineral processing. Traditional deterministic models often fail to capture the nonlinear dependencies and uncertainty inherent in industrial operations such as granulometry, solids percentage in the feeding or hardness. This work develops and validates a stochastic model based on Discrete Bayesian networks (BNs) to represent the causal relationships governing SAG Production and SAG Power under uncertainty or partial knowledge of explanatory variables. Discretization is adopted for methodological reasons as well as for operational relevance, since SAG plant decisions are typically made using threshold-based categories. Using operational data from a Chilean mining operation, the model fitted integrates expert-guided structure learning (Hill-Climbing with BDeu/BIC scores) and Bayesian parameter estimation with Dirichlet priors. Although validation indicators show high predictive performance (R² ≈ 0.85—0.90, RMSE < 0.5 bin, and micro-AUC ≈ 0.98), the primary purpose of the BN is not exact regression but explainable causal inference and probabilistic scenario evaluation. Sensitivity analysis identified water feed and solids percentage as key drivers of throughput (SAG Production), while rotational speed and pressure governed SAG Power behavior. The BN framework effectively balances accuracy and interpretability, offering an explainable probabilistic representation of SAG dynamics. These results demonstrate the potential of stochastic modeling to enhance process control and support uncertainty-aware decision making. Full article

Lake sediments on the Tibetan Plateau serve as crucial carbon sinks in the regional carbon cycles. In recent decades, climate change has triggered significant hydrological changes in many lakes across this region, potentially impacting their carbon-sink functions. Previous studies have predominantly focused on the dynamics of organic carbon burial, largely overlooking the contribution of inorganic carbon sinks, and particularly lacking systematic investigation into the carbon burial processes in lakes experiencing water level decline. Therefore, this study examines a sediment core from Lake Yamzhog Yumco, a lake in the southern Tibetan Plateau with a gradually declining water level. The mineralogical and geochemical analyses of both lake and catchment sediments show that the inorganic carbon (carbonates are dominated by aragonite) and organic carbon are primarily authigenic origin. Over the past four decades, the inorganic carbon burial rate (ICBR) in Lake Yamzhog Yumco has been primarily controlled by water level fluctuations and is closely related to hydrochemical processes regulated by regional climate change. In contrast, the increase in the organic carbon burial rate (OCBR) has been co-influenced by both water level changes and regional temperature. During this period, the ICBR reached as high as 186 g m⁻² yr⁻¹, approximately five times the OCBR. This demonstrates that in lakes in semi-arid regions, the sink potential of inorganic carbon significantly exceeds that of organic carbon, highlighting the necessity of incorporating inorganic carbon burial into carbon-sink assessments. This study provides novel perspectives for a deeper understanding of the driving mechanisms behind carbon burial in Tibetan Plateau lakes and offers a scientific basis for accurately assessing and predicting regional carbon-sink potential. Full article

Ceramic balls, as an emerging grinding medium, require a systematic method for optimizing their size distribution in wet ball mills. This study proposes an innovative approach that integrates Duan’s semi-theoretical ball diameter formula with breakage statistical mechanics to determine the optimal ceramic ball size distribution. The ideal ball diameters for grinding 2.36–3.0 mm, 1.18–2.36 mm, 0.60–1.18 mm, and 0.30–0.60 mm tungsten ore were identified as 55 mm, 50 mm, 35 mm, and 20 mm, respectively. Subsequently, the optimal ball size distribution was formulated as CB3: Ø55 mm:Ø50 mm:Ø35 mm:Ø20 mm = 30%:40%:20%:10%. Comparative sieve analysis and discrete element method (DEM) simulations confirmed that the CB3 distribution yields the highest proportion of qualified particles, the most favorable collision frequency, and the greatest kinetic energy among all tested configurations. The proposed method demonstrates both accuracy and practicality, providing a theoretical foundation for the industrial application of ceramic ball grinding systems. Full article

The Eocene fourth member of the Shahejie formation (Es4x) in the Bonan Depression, Bohai Bay Basin, records syn-rift sedimentation under alternating arid and humid climates. It provides insight into how orbital-scale climatic fluctuations influenced tectonics, facies patterns, and reservoir distribution. This study integrates 406 m of core data, 92 thin sections, 450 km² of 3D seismic data, and multiple geochemical proxies, leading to the recognition of five facies associations (LFA): (1) alluvial fans, (2) braided rivers, (3) floodplain mudstones, (4) fan deltas, and (5) saline lacustrine evaporites. Three major depositional cycles are defined within the Es4x. Seismic reflections, well-log patterns, and thickness trends suggest that these cycles represent fourth-order lake-level fluctuations (0.8–1.1 Myr) rather than short 21-kyr precession rhythms. This implies long-term climate and tectonic modulation, likely linked to eccentricity-scale monsoon variability. Hyperarid phases are marked by Sr/Ba > 4, δ¹⁸O > +4‰, and thick evaporite accumulations. In contrast, Sr/Ba < 1 and δ¹⁸O < −8‰ reflect humid conditions with larger lakes and enhanced fluvial input. During wet periods, rivers produced sand bodies nearly 40 times thicker than in dry intervals. Reservoir quality is highest in braided-river sandstones (LFA 2) with 12%–19% porosity, preserved by chlorite coatings that limit quartz cement. Fan-delta sands (LFA 4) have <8% porosity due to calcite cementation, though fractures (10–50 mm) improve permeability. Floodplain mudstones (LFA 3) and evaporites (LFA 5) act as seals. This work presents a predictive depositional and reservoir model for arid–humid rift systems and highlights braided-river targets as promising exploration zones in climate-sensitive basins worldwide. Full article

The Sanjiang Tethys orogenic belt in Southwest China is a globally important polymetallic metallogenic domain, hosting numerous world-class Cu-Pb-Zn deposits. Among these, the Lanping Basin is a typical ore concentration area, characterized by complex tectonic evolution and extensive hydrothermal mineralization. Although numerous vein-type Cu deposits occur in the northern and western parts of the basin, research in the north region remains less comprehensive. This study investigates three typical vein-type Cu deposits (Hetaoqing, Hemeigou, and Songpingzi) in the northern Lanping Basin using rare-earth element (REE) analysis, S-Pb-Sr isotope determinations, and tectonic stress inversion. Results show that ²⁰⁶Pb/²⁰⁴Pb ratios range from 18.374 to 18.691, and δ³⁴S_V-CDT values vary from –11.7‰ to +9.4‰, indicating mixed sources of ore-forming materials dominated by deep magmatic sources, particularly related to alkaline rocks around the basin. Sulfur sources are closely associated with thermochemical sulfate reduction (TSR). Additionally, ⁸⁷Sr/⁸⁶Sr ratios range from 0.710949 to 0.711864, ΣREE values range from 85.87 × 10^–6 to 111.86 × 10^–6, Ce/Ce* ratios range from 0.86 to 0.92, and Eu/Eu* ratios range from 1.06 to 2.99. Fluid inclusion microthermometry yields temperatures of 217–252 °C (average 238 °C), indicating that ore-forming fluids experienced water–rock interaction during migration and ultimately exhibited mixed properties. Tectonic stress field inversion reveals that the structures formed by NE–SW compressive stress field before mineralization stage provided ore-hosting spaces and fluid migration pathways, while a late Cenozoic abrupt stress field change promoted the precipitation of ore-forming materials. Full article

High-precision gravity surveys are effective in detecting concealed geological structures and mineral deposits with density contrasts. In this study, 754 dense gravity measurements (average accuracy: 0.0043 mGal, or 4.3 × 10⁻⁸ m/s²) were deployed in Dingzhai Township, northeastern Zhejiang, China, to investigate concealed ore bodies and structural controls on mineralization. Using the mean-field method for source-field separation of Bouguer anomalies, combined with density inversion and edge detection, we delineated subsurface density distributions and fault systems. A newly identified “tongue-shaped” high-density anomaly near Xiashadi is interpreted as resulting from local upward intrusion of intermediate-acid porphyry from the Chencai Group basement, indicating significant exploration potential. Beneath Quaternary cover, a previously unrecognized east–west-trending concealed fault was detected, which may have controlled the structural evolution of mineralization at the Daqi’ao Ag deposit and Miaowan Cu deposit. Gravity profile inversion reveals a deep high-density anomaly beneath Xie’ao–Xi’ao’an, possibly representing the deep extension of the Hengtang Cu–Mo deposit. Low-density anomalies near Chenxi and Dongli villages are attributed to Early Cretaceous low-density intrusions (e.g., monzogranite) and multi-phase volcanism in the Shangshawan caldera. This work provides robust geophysical constraints for deep mineral exploration and advance understanding of the metallogenic tectonic evolution in northeastern Zhejiang. Full article

To elucidate the refractory depression of serpentine in a Jinchuan copper-nickel ore (Located in Gansu Province), this study compared the effects of serpentine from Gansu and Liaoning on chalcopyrite flotation via single/mixed mineral flotation, zeta potential, micro-polarity detection, XPS, ToF-SIMS, and EPMA. Single mineral flotation showed chalcopyrite recovery reached ~90% at pH < 8 with 60 mg/L DDTC, while Gansu serpentine had slightly higher recovery than Liaoning serpentine. In mixed mineral flotation, chalcopyrite recovery dropped to ~70% (pH = 8), and Gansu serpentine recovery rose to ~45% (vs. ~35% for Liaoning). When 40 mg/L CMC inhibitor was added, chalcopyrite recovery restored to ~80%, and both serpentines’ recovery fell below 20%—but serpentine (Gansu) still had marginally higher recovery. The zeta potential and micro-polarity experiments collectively indicate that the collector exhibits selective adsorption on the surface of chalcopyrite; compared between the two serpentine samples, the collector adsorption is stronger on the surface of Gansu serpentine. In contrast, the depressant shows selective adsorption on the surface of serpentine, but when comparing the two serpentine samples, the depressant adsorption is stronger on the surface of exotic serpentine. This finding to a certain extent explains the reason why Gansu serpentine is difficult to depress. EPMA showed Gansu serpentine had lower MgO (38.668% vs. 41.012% for Liaoning), and XPS exhibited smaller Mg 1s shifts (1.93 eV vs. 4.46 eV) with CMC. This study explains Gansu serpentine’s poor depressibility, providing critical support for optimizing Cu-Ni ore flotation reagents and processes, gradually bridging to industrial application. This work provides a universal framework for global low-grade copper-nickel ores with silicate gangues. Full article

The Jiulongnao W–Sn ore field in the eastern Nanling Range is characterized by large-scale early Yanshanian magmatic activity and W–Sn mineralization. In recent years, increasing attention has been given to the close relationship between Indosinian magmatic activity and Sn mineralization. The Aotou quartz vein-type Sn deposit is unique for only Sn mineralization without W during the Indosinian period. Seventeen thin-to-thick cassiterite–quartz veins are densely distributed in Ordovician metasandstone and slate, and these veins extend down to the top of the concealed granite. However, both the diagenetic age and the petrological characteristics of the concealed granite remain unclear. This contribution shows that the Aotou muscovite intrusion is a highly fractionated S-type pluton, characterized by a peraluminous, high-K composition, enrichment in LREEs, and depletion of Ba, Sr, Ti, and Eu. In this study, LA–ICP–MS zircon U–Pb dating of the concealed muscovite granite yields emplacement ages of 238.7 ± 1.0 Ma and 225.4 ± 0.9 Ma, indicating that at least two stages of magmatic intrusion occurred in the Triassic, with the diagenetic environment transitioning from a compressional setting to an extensional setting. The ε_Hf(t) values during the two stages are −0.98 to −0.95 and −0.98 to −0.96, and the T_DM2 values are 1.78–2.08 Ga and 1.78–2.06 Ga, indicating that two-stage magma was derived from the late Paleoproterozoic lower crustal materials. Comprehensive analysis reveals that the second stage of Indosinian magma intrusion (232–225 Ma) in the Jiulongnao ore field is closely related to Sn mineralization, and the northern Wenying pluton has good prospecting potential for quartz vein-type Sn(–W) deposits. Full article

Through this work, an experimental setup and pre-processing method for obtaining fluorescence and quasi-noise-free Raman spectra of minerals for in situ mineral identification in an underground environment is proposed. It uses a combination of methodologies like dual excitation wavelengths, Shifted Excitation Raman Difference Spectroscopy (SERDS), and deep learning-based U-Net model for background and noise correction. The dual excitation wavelengths technique employs a near-infrared SERDS laser for the fingerprint and a red laser for the large Raman shift region. The SERDS laser operates at two excitation wavelengths and is tuneable in the vicinity of 785 nm. The red laser uses 671 nm excitation wavelength. The obtained fingerprint and large Raman shift Raman spectra are then fed to a pre-processing method containing the trained U-Net model for obtaining a background-corrected and quasi-noise-free Raman spectrum. The proposed method addresses issues of existing handheld Raman systems in terms of spectrometer sensitivity, spectrum acquisition speed, pre-processing time, fluorescence effects, and other interferences due to surrounding light or vibration. The obtained final processed Raman spectrum is then deconstructed into pseudo-Voigt peaks. The identification of the minerals can be based on the number and the positions of the pseudo-Voigt peaks. Samples of gypsum (CaSO₄·2H₂O) and anhydrite (CaSO₄) were used for evaluating the performance of the proposed method. The influence of measurement time on the reproducibility and precision of the peak identification and, thus, mineral identification is also analyzed. Full article

We present an integrated methodology for three-dimensional inversion of large-scale airborne electromagnetic (AEM) and magnetic survey data that simultaneously recovers electrical conductivity, chargeability, and both induced and remanent magnetizations. A central feature of the AEM component is the explicit incorporation of induced polarization (IP) effects. Neglecting IP responses can lead to biased conductivity models, particularly in mineralized systems where disseminated sulfides contribute strongly to chargeability. Using the Generalized Effective-Medium Theory of Induced Polarization (GEMTIP), the inversion produces physically consistent 3D distributions of conductivity and chargeability. To enhance magnetic interpretation, we also implement a vector magnetic inversion that resolves both induced and remanent magnetization from Total Magnetic Intensity (TMI) data, enabling geologically realistic magnetization models in terranes with significant remanence. This integrated workflow was applied to airborne AEM and TMI datasets collected over the Asankrangwa Gold Belt in central Ghana. The inversion results delineate a key exploration target defined by coincident magnetic low and elevated chargeability, interpreted as sulfide-rich gold mineralization and subsequently confirmed by drilling. These results demonstrate that jointly accounting for IP and remanent magnetization in 3D inversion substantially improves subsurface characterization and provides a powerful tool for mineral exploration in structurally and lithologically complex environments. Full article

Lava tubes on Earth provide unique hydrogeological niches for life to proliferate. Orbital observations of the Martian surface indicate the presence of lava tubes, which could hold the potential for extant life or the preservation of past life within a subsurface environment protected from harsh conditions or weathering at the surface. Secondary minerals in lava tubes form as a combination of abiotic and biotic processes. Microbes colonize the surfaces rich in these secondary minerals, and their actions induce further alteration of the mineral deposits and host basalts. We conducted a biogeochemical investigation of basaltic lava tubes in the Medicine Lake region of northern California by characterizing the compositional variations in secondary minerals, organic compounds, microbial communities, and the host rocks to better understand how their biogeochemical signatures could indicate habitability. We used methods applicable to landed Mars missions, including Raman spectroscopy, X-ray diffraction (XRD), Laser-Induced Breakdown Spectroscopy (LIBS), and gas chromatography–mass spectrometry (GC-MS), along with scanning electron microscopy (SEM) and metagenomic DNA/RNA sequencing. The main secondary minerals, amorphous silicates, and calcite, formed abiotically from the cave waters. Two types of gypsum, large euhedral grains with halites, and cryptocrystalline masses near microbial material, were observed in our samples, indicating different formation pathways. The cryptocrystalline gypsum, along with clay minerals, was associated with microbial materials and biomolecular signatures among weathered primary basalt minerals, suggesting that their formation was related to biologic processes. Some of the genes and pathways observed indicated a mix of metabolisms, including those involved in sulfur and nitrogen cycling. The spatial relationships of microbial material, Cu-enriched hematite in the host basalts, and genetic signatures indicative of metal cycling also pointed to localized Fe oxidation and mobilization of Cu by the microbial communities. Collectively these results affirm the availability of bio-essential elements supporting diverse microbial populations on lava tube basalts. Further work exploring these relationships in lava tubes is needed to unravel the intertwined nature of abiotic and biotic interactions and how that affects habitability in these environments on Earth and the potential for life on Mars. Full article

Precise segmentation of flotation froths is a critical bottleneck to achieving intelligent perception and optimal control of process operations. Traditional convolutional neural networks (CNNs) are inherently limited by local receptive fields, making it challenging to accurately segment adhesive and multi-scale froths. To address this fundamental issue, this paper proposes a deep segmentation network with integrated global context awareness, termed GC-FSegNet, which establishes a new paradigm capable of jointly modeling macro-level structures and micro-level details. The proposed GC-FSegNet innovatively integrates the Global Context Network (GCNet) module into both the encoder and decoder of a Nested U-Net architecture. The GCNet captures long-range dependencies between froths, enabling macro-level modeling of clustered foam structures, while the Nested U-Net preserves high-resolution boundary details. Through their synergistic interaction, the model achieves simultaneous and efficient representation of both global contours and local details of froth images. Furthermore, the Mish activation function is employed to enhance the learning of weak boundary features, and a combined Dice and Binary Cross-Entropy (BCE) loss function is designed to optimize boundary segmentation accuracy. Experimental results on a self-constructed copper–lead flotation froth dataset demonstrate that GC-FSegNet achieves an mDice of 0.9443, mIoU of 0.8945, mRecall of 0.9866, and mPrecision of 0.9705, significantly outperforming mainstream models such as U-Net and DeepLabV3+. This study not only provides a reliable technical solution for high-adhesion froth segmentation but, more importantly, introduces a promising “global–local collaborative modeling” framework that can be extended to a wide range of complex industrial image segmentation scenarios. Full article

Calcareous sandstones, acting as sealing layers, play a crucial role in hydrocarbon accumulation of formations with high sand content (sand content > 80%). However, the genetic mechanisms, sealing mechanisms, and effectiveness of calcareous sandstones remain unclear. This study takes the Zhuhai–Enping formations in the Panyu A Sag as an example. By comprehensively analyzing data from well logs, cores, cast thin sections, elemental geochemical analysis and carbon–oxygen isotopes, the genetic mechanisms, development patterns, and controlling effects on hydrocarbon accumulation of calcareous cement layers are investigated. The main findings are as follows: (1) The calcareous sandstone cements are mainly composed of dolomite, ankerite, and anhydrite. With increasing burial depth, dolomite transitions from micritic dolomite to silt-sized and fine-crystalline dolomite, and finally to coarse-crystalline dolomite. (2) The local transgression provided ions such as Ca²⁺ and Mg²⁺, forming the material basis for early dolomite formation. As burial depth increased, the diagenetic environment shifted from acidic to alkaline, leading to the dolomitization of early-formed calcite and the formation of ankerite. (3) The high source-reservoir displacement pressure difference effectively seals hydrocarbon accumulation. Vertically interbedded tight calcareous sandstones and thin marine transgressive mud-stones collectively control efficient hydrocarbon preservation and enrichment. This research addresses the current limits in the study of “self-sealing sandstone layers,” and provides new geological insights and predictive models for hydrocarbon exploration in sand-rich settings. Full article

This review provides a comprehensive analysis of the petrophysical controls influencing greensand reservoirs, with an emphasis on the role of glauconite and associated clay minerals in determining porosity, permeability, and water saturation. Greensands contain iron-rich clay minerals that exert paramagnetic and conductive effects, challenging conventional well-log interpretations and often leading to biased estimates of reservoir parameters. Several challenges for petrophysical property measurements are faced in the laboratory due to clay-induced pore-throat obstruction and microporosity, which underscores the importance of tailored interpretation workflows and data integration. In this paper we highlight the necessity of integrated approaches such as combining core analysis, spectral gamma-ray, and nuclear magnetic resonance (NMR) logging with conventional well logs to calibrate petrophysical models using shale–sand water saturation models, such as Waxman–Smits and Simandoux, to better characterise economical pay zones. Finally, future research directions are indicated, which include refining the calibration of saturation and permeability models, advancing rock-typing methodologies, and understanding mineralogical influences on reservoir quality to optimise hydrocarbon recovery from greensand reservoirs. Full article

This paper presents the results of an integrated targeting study covering the central-eastern Archean Yilgarn Craton of Western Australia, a region renowned for its substantial gold endowment (>40 Moz Au). The cornerstones of this study included custom-built geophysical and remote sensing targeting tools, a new lithostructural interpretation of the area, a targeting model based on the mineral systems approach, and a best-practice mineral potential modeling (MPM) workflow employing five complementary modeling techniques. The geophysical targeting tools were used to identify proximity, association, and abundance relationships between gold mineralization and gravity ridges or edges, as well as 95th-percentile K/Th radiometric and remotely sensed goethite–clay–iron feature depth index ratio anomalies. The lithostructural interpretation revealed structural trends oblique or orthogonal to the NNW-SSE-striking greenstone belts, likely representing important structural controls on gold mineralization. Fry analysis, used to assess the spatial distribution of geological point patterns, showed similar directions of maximum gold occurrence alignment. Together, these observations proved to be strong predictors of gold prospectivity in the MPM component of this targeting study. The MPM not only identified most known gold occurrences but also highlighted several underexplored areas with significant potential. The highest-priority MPM targets represent roughly an order-of-magnitude reduction in search space, the hallmark of a well-performing and practically useful targeting methodology. Full article

The Shawan Sag and its adjacent areas are rich in hydrocarbon resources. Moreover, the genesis and evolution patterns of zeolite cements in the sandy conglomerate reservoirs have resulted in diverse types of reservoir spaces, a complex composition, and significant heterogeneity. To investigate their impact on reservoir quality, this study integrates core observations, thin-section petrography, scanning electron microscopy (SEM), whole-rock X-ray diffraction (XRD), and energy-dispersive spectroscopy (EDS) for macro–micro comparative analysis of zeolite cement types, formation mechanisms, and pore systems in the Lower Permian strata of the Shawan Sag and adjacent areas. Research demonstrates that provenance exerts a control on type and origin of the diagenetic zeolites: In the Shawan Sag, zeolites form through hydration of volcanic glass in tuff, while adjacent areas develop zeolites via albitization of plagioclase derived from andesite. This genetic divergence drives pore differentiation: Zeolite (heulandite and laumontite) evolution in the Sag generates grain-edge fractures through cement volume shrinkage and crystalline water release. In contrast, the adjacent areas exhibit reservoir spaces dominated by dissolution pores, resulting from the dissolution of laumontite and calcite, along with a relatively higher overall rock porosity. Full article

Mining activities have caused widespread land degradation and contamination, affecting millions of hectares worldwide and posing persistent ecological risks. However, reclamation substrates are constrained by limited availability and compromised quality, which restricts their ability to fully support mine ecological restoration. Among various amendment materials, biomass-based amendments have been widely applied due to their broad availability, renewability, biodegradability, and low cost. In recent years, their role has expanded beyond simple nutrient supplementation to encompass multiple functions, including structural optimization, pollutant stabilization, and microbial regulation. This review highlights the valorisation of biomass-derived solid wastes as multifunctional amendments for mine ecological restoration. By converting agricultural and industrial wastes into green materials, these amendments improve substrate structure, stabilize heavy metals and organic pollutants, enhance nutrient cycling, and stimulate microbial activity. Potential risks, including nutrient leaching, secondary pollution, and greenhouse gas emissions, are critically assessed, with emphasis on their variability under different environmental conditions. By integrating functional benefits with ecological risks, this work underscores the critical role of biomass-based amendments as waste-to-resource strategies in advancing sustainable mine reclamation, contributing to circular economy goals, and supporting environmental engineering practices. Full article

The spatial relationships of the widely distributed latest Jurassic–Early Cretaceous igneous rocks in the Tethyan Himalaya, northeastern India, and southeastern Australia are crucial for understanding the breakup of eastern Gondwana. However, available paleomagnetic datasets from the central Tethyan Himalaya are limited. To better constrain the distribution of these igneous rocks, new paleomagnetic data were obtained from the Weimei Formation volcanic rocks in the central Tethyan Himalaya. The tilt-corrected site-mean directions for 11 sites is Ds = 315.4°, Is = −58.4°, ks = 17.2, α₉₅ = 11.3°, corresponding to a paleopole at 9.6° N, 297.3° E with dp/dm = 16.7°/12.4° and a paleolatitude of ~39.1 ± 12.4° S for the study area (29.7° N, 83.7° E). A positive regional fold test and the occurrence of dual polarity suggest that the characteristic remanent magnetization is of pre-fold origin. These new results, together with those from the eastern Tethyan Himalaya, northern India, and southwestern Australia, show that the ~147–130 Ma circum-eastern Gondwana large igneous province spans a latitudinal range of ~40.7–58.1° S, centered at ~49.4° S, which is consistent with the present Kerguelen hotspot (~49.0° S). Integrating other evidence, we consider that the Kerguelen mantle plume played a key role in the breakup of eastern Gondwana. Full article

Until 2021, experimental data on polysulfide groups in feldspathoids were limited to the properties of the S₃^•− chromophore center and the S₂^•− luminescence center in sodalite-group minerals. Interpretation of some spectroscopic data on other S-bearing groups in feldspathoids remained ambiguous because of significant differences between calculated data for isolated polysulfide species and experimental data for polysulfide groups in liquid sulfur, solutions, and matrix-isolated species published in different literature sources. For this reason, configurations of stable and metastable structures and parameters of the absorption spectra in the ultraviolet, visible, and near-infrared (UV-Vis-NIR) region and in the ESR and Raman spectra of various structure modifications of polysulfide S_n²⁻ anions, S_n^•− radical anions, and S_n neutral molecules (n = 2–6) as well as HS⁻ in the sodalite cage of sapozhnikovite have been calculated in frames of the density functional theory using the VASP and ORCA software packages. Taking into account the obtained results of theoretical calculations, spectroscopic properties of extra-framework polysulfide groups in natural tectosilicates belonging to the cancrinite and sodalite groups are discussed. The obtained results made it possible to confirm and partially clarify the interpretation of the experimental spectroscopic data for S-containing feldspathoids obtained by the authors of this work over the past five years. Full article

The low recovery of fine chalcopyrite particles and the limited Cu/Fe selectivity with conventional thiol collectors prompted the evaluation of a Polystyrene–Divinylbenzene–Cetyltrimethylammonium Bromide–Potassium Amyl Xanthate (PS-DVB-CTAB-PAX) polymeric nanocollector. The copolymer was synthesized by emulsion polymerization and characterized using Total Organic Carbon (TOC) analysis, Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Particle Size Analysis, and contact angle measurement. Its performance was tested in a Hallimond cell (150 mL) using a synthetic industrial water solution (0.010 mol/L NaCl + 0.005 mol/L CaCl₂) at a natural pH range of 6.0 to 8.0. PAX concentrations ranged from 0 to 16.19 mg L⁻¹, and nanocollector doses equivalent to 0 to 45 mg g⁻¹ of solid were tested. The nanocollector increased chalcopyrite recovery to 98 ± 1% for the −53 + 38 µm size fraction and maintained values greater than 95% in the coarse fractions, outperforming PAX across the entire dosage range. The PAX + nanocollector combination achieved the same recovery by reducing the total xanthate dosage by one-third, demonstrating a synergistic effect. TOC assays showed preferential adsorption of 96.6% on chalcopyrite versus 86.4% on pyrite, a difference that explains the observed Cu/Fe selectivity (pyrite floatability < 70%). The contact angle of chalcopyrite increased from 56.4° (water) to 86.5° in the presence of the nanocollector, demonstrating the generation of localized superhydrophobicity that reduces interfacial free energy and favors bubble–particle adhesion, whereas pyrite showed lower values of 51.1°, 58.3°, and 75.1°, confirming its more hydrophilic nature. These findings indicate that PS-DVB-CTAB-PAX enables optimized copper sulfide recovery, reduced thiol collector consumption, and improved metallurgical selectivity, making it a promising alternative for flotation circuits with high ionic strength water and for scaling up to pilot tests. Full article

The Yanlinsi gold deposit, located in the middle section of the Jiangnan Orogenic Belt, is one of the typical gold deposits in northeastern Hunan Province. Diabase dikes are exposed by underground workings and drill holes in the mining area. The dikes strike NW and cut the NE-trending gold ore body. To investigate the petrogenetic age, characteristics of the magmatic source area, and tectonic setting of the diabase dikes in the Yanlinsi gold mining area, northeastern Hunan, and to determine the mineralization age of the deposit, in this paper, diabase dike LA-ICP-MS zircon U-Pb dating, whole-rock geochemistry, and gold-bearing quartz vein LA-ICP-MS zircon U-Pb dating were studied. The results of LA-ICP-MS zircon U-Pb dating indicate that the diabase was emplaced at an age of 219.5 Ma, belonging to the late Indosinian. The investigated diabase dikes are characterized by low SiO₂ (43.68%–46.55%), high MgO (7.78%–9.84%), and high Mg# (65.0–68.7) values, belonging to the alkaline basalt series with high potassium. The chondrite-normalized REEs patterns show highly fractionated LREEs and HREEs ((La/Yb)_N = 11.21–14.82), and the primitive mantle-normalized spider patterns show enrichment in large ion lithophile elements (e.g., Rb, Ba, K and Sr) and relative depletion in high field strength elements (e.g., Nb, Ta, and P), similar to those of ocean island-like basalt (OIB). Rock geochemical characteristics indicate that the magma of the Yanlinsi diabase was formed by partial melting of the enriched mantle (EM II), with the source region being spinel-garnet lherzolite. The degree of partial melting was approximately 10%–15%, and the assimilation and contamination with continental crustal materials were weak. Meanwhile, weak fractional crystallization of olivine, clinopyroxene, and apatite occurred during the magma evolution process. On the basis of a synthesis of previous research results, it is concluded that the Yanlinsi diabase formed in an extensional tectonic setting after intracontinental collisional orogeny. The LA-ICP-MS U-Pb age of hydrothermal zircons from quartz veins in the main mineralization stage of the Yanlinsi gold deposit is 421.9 ± 1.5 Ma. Combined with the cross-cutting relationships between mafic dikes and gold veins (ore bodies), it is determined that the main mineralization stage of the deposit formed during the Caledonian Period. Full article

Wettability significantly influences fluid distribution and flow behavior in hydrocarbon reservoirs, yet traditional macroscopic measurements fail to capture the micro- and nanoscale interfacial interactions that govern these processes. This study addresses a critical knowledge gap by employing molecular dynamics simulations to systematically investigate how salinity and mineral composition control wettability at the atomic scale—insights that are experimentally inaccessible yet essential for optimizing enhanced oil recovery strategies. We examined five typical reservoir minerals—kaolinite, montmorillonite, chlorite, quartz, and calcite—along with graphene as a model organic surface. Our findings reveal that while all minerals exhibit hydrophilicity (contact angles below 75°), increasing salinity weakens water wettability, with Ca²⁺ ions exerting the strongest effect due to their high charge density, which enhances electrostatic attraction with negatively charged mineral surfaces and promotes specific adsorption at the mineral–water interface, thereby displacing water molecules and reducing surface hydrophilicity. In oil–water–mineral systems, we discovered that graphene displays exceptional oleophilicity, with hydrocarbon interaction energies reaching −7043.61 kcal/mol for C₁₈H₃₈, whereas calcite and quartz maintain strong hydrophilicity. Temperature and pressure conditions modulate interfacial behavior distinctly: elevated pressure enhances molecular aggregation, while higher temperature promotes diffusion. Notably, mixed alkane simulations reveal that heavy hydrocarbons preferentially adsorb on mineral surfaces and form highly ordered structures on graphene, with diffusion rates inversely correlating with molecular size. These atomic-scale insights into wettability mechanisms provide fundamental understanding for designing salinity management and wettability alteration strategies in enhanced oil recovery operations. Full article

The Wushan Loess, situated in the Yangtze Three Gorges region of China, represents the southernmost aeolian loess deposit in China and provides critical insights into Late Pleistocene paleoenvironmental conditions and East Asian monsoon dynamics. Despite its significance, the genesis and provenance of this unique loess deposit remain controversial. This study employs an integrated multi-proxy approach combining detrital zircon U-Pb geochronology, optically stimulated luminescence (OSL) dating, and detailed grain size analysis to systematically investigate the provenance and depositional mechanisms of the Wushan Loess. Three representative loess–paleosol profiles (Gaotang-GT, Badong-BD, and Zigui-ZG) were analyzed, yielding 17 OSL ages, 729 grain size measurements, and approximately 420 analyses per profile were conducted, yielding 1189 valid ages (GT 406, BD 391, ZG 402). OSL chronology constrains the deposition period to 18–103 ka (Marine Isotope Stages 2–5), coinciding with enhanced East Asian winter monsoon activity during the Last Glacial period. Grain size analysis reveals a dominant silt fraction (modal size: 20–25 μm) characteristic of aeolian transport, with coarse silt (20–63 μm) averaging 47.1% and fine silt (<20 μm) averaging 44.2% of the sediments. Detrital zircon U-Pb age spectra exhibit consistent major peaks at 200–220 Ma, 450–500 Ma, 720–780 Ma, and 1800–1850 Ma across all profiles. Kernel Density Estimation (KDE) and Multi-Dimensional Scaling (MDS) analyses indicate a mixed provenance model. Non-negative least squares (NNLS) unmixing confirms this quantitative source apportionment., dominated by proximal contributions from the upper Yangtze River basin (including the Three Gorges area and Sichuan Basin, ~65%–70%), supplemented by distal dust input from the Loess Plateau and northern Chinese deserts (~30%–35%). This study establishes for the first time a proximal-dominated provenance model for the Wushan Loess, providing new evidence for understanding southern Chinese loess formation mechanisms and Late Pleistocene East Asian monsoon evolution. Full article

In mineral processing and metallurgy, total iron grade serves as a critical indicator guiding the entire production chain from crushing to smelting, directly influencing the quality and yield of steel products. To address the limitations of conventional matrix effect correction methods in X-ray fluorescence (XRF) analysis—such as low accuracy, high time consumption, and labor-intensive procedures—this study proposes a novel hybrid model (DSCN-LS) integrating least squares (LS) with dynamically regularized stochastic configuration networks (DSCNs) for total iron ore grade quantification. Through feature analysis, we decompose the grade modeling problem into a linear structural component and nonlinear residual terms. The linear component is resolved by means of LS, while the nonlinear terms are processed by the DSCN with a dynamic regularization strategy. This strategy implements node-specific weighted regularization: weak constraints preserve salient features in high-weight-norm nodes, while strong regularization suppresses redundant information in low-weight-norm nodes, collectively enhancing model generalizability and robustness. Notably, the model was trained and validated using datasets collected directly from industrial sites, ensuring that the results reflect real-world production scenarios. Industrial validation demonstrates that the proposed method achieves an average absolute error of 0.3092, a root mean square error of 0.5561, and a coefficient of determination (R²) of 99.91% in total iron grade estimation. All metrics surpass existing benchmarks, confirming significant improvements in accuracy and operational practicality for XRF detection under complex industrial conditions. Full article

Accurate grade prediction in porphyry copper deposits requires not only capturing spatial continuity but also accounting for geological controls. This study evaluates the added value of incorporating alteration and mineralization domains into machine learning (ML) models for copper grade estimation at the Iju porphyry Cu deposit, Iran. We compare four scenarios: spatial coordinates only, coordinates + alteration, coordinates + mineralization, and coordinates + both domains. A three-stage workflow was developed, in which Random Forest classifiers—optimized with Particle Swarm Optimization (PSO-RF)—classify alteration and mineralization zones, which are later integrated into regression models for ore grade prediction. Model performance was assessed using nested spatial cross-validation and benchmarked against Support Vector Machines (SVM). In comparative analysis, the PSO-RF framework consistently outperformed SVM, achieving more balanced accuracy between training and testing data and demonstrating greater robustness to class imbalance in domain classification. Moreover, results show that combining alteration and mineralization domains improves predictive performance (R² = 0.78; RMSE was reduced by 5.6% relative to coordinates-only). Although numerically moderate, this reduction in error translates into more reliable tonnage and grade estimations near cut-off grades, thereby enhancing the economic confidence of resource evaluations. These findings demonstrate that integrating multiple geological domains can improve both the accuracy and interpretability of ML-based grade models, providing a practical and reproducible workflow for porphyry copper resource evaluation. Full article

This study analyzes clay sources, ceramic paste recipes, and technological choices in Neolithic pottery from west Lithuania, where local hunter–fisher–gatherer groups encountered incoming communities of the Globular Amphora (GAC) and Corded Ware cultures (CWC) during the fourth to third millennium BCE. Thirty sherds from coastal Šventoji and the inland Biržulis region were analyzed by optical microscopy and SEM–EDS, revealing that most ceramic pastes comprise variegated hydromicaceous clay with quartz and feldspar. In Narva Culture pottery, vessels from the Biržulis region (Daktariškė 5) are dominated by fine-grained clay, whereas Šventoji examples are more variegated and diatom-bearing; both assemblages show organic inclusions (mussel shell, bone, charred plant material) and very low firing temperatures (<650 °C). GAC exhibits cross-site coherence, characterized by crushed, deformed, cataclastic muscovite granite in fine lacustrine clay and low firing temperatures (~650–750 °C). CWC from Daktariškė 5 geochemically clusters with Narva and hybrid-type pottery, while CWC at Šventoji aligns with GAC; both show low firing temperatures (~650–750 °C). Ceramic pastes contain argillaceous clasts partly diffused or intertwined with the main matrix; only a few show traits typical of grog. All pottery was made from local Quaternary glacial sediments, with cultural traditions and environmental context shaping clay selection and manipulation. Full article

Optimizing beneficiation processes in the iron ore industry is essential to meet increasing demand while dealing with declining ore grade. Since grinding has a major impact on product quality and production costs, the implementation of Advanced Process Control (APC) emerges as an effective strategy to enhance efficiency and operational stability. This study quantifies the operational improvements achieved after the implementation of an APC system in the ball grinding circuit of the Mineração Usiminas industrial processing plant. The assessment was based on an ON/OFF test conducted over 67 days, during which operational data were collected for periods with the APC system enabled and disabled, supported by statistical tests and a literature review. The results show significant improvements in both stability and throughput under the unconstrained operating scenario. The standard deviation of the hydrocyclone feed pulp density setpoint decreased by 63%, while the circuit throughput increased from 541 to 571 tph. Moreover, the specific energy consumption was reduced by more than 5% in the same scenario. These findings demonstrate the tangible benefits of implementing Advanced Process Control in industrial grinding operations. Full article

The consistency between geochemical discrimination diagrams and the modal Quartz–Alkali feldspar–Plagioclase (QAP) classification scheme was investigated by evaluating the accuracy of three diagrams—the Quartz–Plagioclase coordinates (P-Q), the SiO₂–CaO/(CaO + K₂O) (SCK), and the Silica–Total Alkali (TAS) diagrams—for granitoid rocks. A global dataset of 1981 samples, each containing both whole-rock geochemical data and quantitative modal mineralogy, was employed. The results indicate that the P-Q and SCK diagrams have relatively low overall accuracy (~50%–55%) in reproducing the QAP classification. Their accuracy is acceptable for granites but notably lower for basic and intermediate rock types. The SCK diagram achieves higher accuracy (~80%) for tonalite but exhibits considerable dispersion for other lithologies. Despite the IUGS recommending the TAS diagram for volcanic rocks only, it is commonly used for intrusive rocks; this study, however, finds that it yields low accuracy rates for most common plutonic rocks and is therefore unsuitable for their reliable classification. This limited accuracy is attributed to the use of only three or four oxides to estimate major mineral proportions, a practice equivalent to dimensionality reduction that results in substantial information loss. Full article

Predicting mineral deposits accurately requires capturing the complex interactions among geological structures, geochemical anomalies, and alteration patterns. To address this challenge, this study develops a Knowledge–Data Collaboration Graph Attention Network (KDCGAT) to improve copper mineralization prediction by integrating multi-source geological data. The model combines Graph Attention Network (GAT) with multimodal geoscience data, including fracture structures, remote sensing alteration maps, and geochemical anomalies. Spatial correlations are captured through a self-attention mechanism, aligning deep learning predictions with geological and geochemical knowledge. Using the eastern Tien Shan copper belt in Xinjiang as a case study, KDCGAT achieves a copper deposit identification accuracy of 85.9%, outperforming Weight of Evidence (WoE) by 7%, Graph Convolutional Network (GCN) by 11.3%, and Convolutional Neural Network (CNN) by 19.7%. Ablation experiments show a 21.1% improvement over the baseline GAT model. Finally, five Class A and three Class B mineralization prediction zones are delineated. This study demonstrates the effectiveness of graph neural networks for copper prospectivity prediction and highlights knowledge–data collaboration as a practical tool for mineral exploration. Full article

Structures resembling iron-related bacteria (IRB) have been found in the Mississippian limestones that form part of the carbonate platform in the Moravo-Silesian Basin that surrounds the Upper Silesian Block, an eastern margin of the Brunovistulicum. Microfacial, petrological, and geochemical analyses were used to determine the bacteria-like structures that are present in narrow zones unrelated to bedding. We present here the morphology and chemistry of the studied microstructures showing their similarities to IRB from the present-day Sphaerotilus-Leptothrix group, the Galionella group, and the Mariprofundus ferrooxydans species. We suggest that bacterial growth occurred in the originally empty micropores of microfossil skeletons and shells, between bioclasts or in secondary voids formed during the selective dissolution of micrite or smaller sparite crystals. Hydrothermal solutions, associated probably with the post-Variscan magmatism in this area, provided iron compounds for the growth of the IRB. Full article

Thorium-rare earth-iron oxide deposits of the Lemhi Pass district, Idaho and Montana, are enriched in the middle rare earth elements (REE), and particularly neodymium (Nd). Overall, thorium (Th) and total rare earth oxide (TREO) grades of the deposits are sub equal at 0.4 wt. % but locally exceed 1 wt. % TREO. Nd-monazite, the major REE phase (35 wt. % Nd₂O₃) occurs in hydrothermal Th-REE mineralized quartz veins and biotite-rich shear zones of enigmatic origin. Hosted in Mesoproterozoic metasedimentary rocks, the deposits are modest in size but present over a large area with no obvious source pluton exposed. This paper documents the geochemistry of the monazite and provides the first geochronological data to constrain its origin. Elemental mapping and U-Th-total Pb EPMA dating of the monazite and thorite document a Paleozoic age for mineralization centered in the Late Devonian at approximately 355 Ma ± 20 Ma. A second period of volumetrically minor Th and REE remobilization is dated as Mesozoic (ca. 100 Ma). For context, a reactivated passive continental margin was present during the Devonian in eastern Idaho, while the Mesozoic was a time of major accretionary tectonics and arc magmatism further west. Nd and Pb isotopic data require a significant interaction of the fluids with an ancient crustal component represented by regional Mesoproterozoic metasedimentary rocks and granitoids. A source–transport–deposition model is hypothesized with metasomatic fractionation and enrichment of Nd during regional hydrothermal circulation. The aqueous fluids were hot, oxidizing, and likely saline, but the exact source of the Th and REEs and the mechanism of enrichment remains problematic. Additional analytical work and increased knowledge of the regional and district geology will improve this unconventional hypothesis for formation of Lemhi Pass’ unusual Nd-rich Th-REE-Fe mineralization. Full article

The shell liner is a core component of Semi-Autogenous Grinding (SAG) mills, suffering severe wear from ore impact and friction, and its shape directly affects grinding efficiency and maintenance costs. In this study, the Finnie wear model in EDEM2022 software was improved to predict the wear morphology evolution of shell liners. A Python-based coupled simulation of the Discrete Element Method (DEM, EDEM) and Finite Element Method (FEM, ABAQUS) was established to analyze liner wear mechanisms, stress states, and mill service performance (wear resistance, grinding efficiency, and stress distribution). The simulated wear profile showed high consistency with laser three-dimensional scanning (LTDS) results, confirming the improved Finnie-DEM model’s effectiveness in reproducing liner wear evolution. Shearing in crushing/grinding zones was the main wear cause, with additional contributions from relative sliding among ore, grinding balls, and liners in grinding/discharge zones. DEM-FEM coupling revealed two circumferential instantaneous wear extremes (Max^a > Max^b) and two lifter wear rate peaks (M^a > M^b). In the grinding zone, liner stress distribution matched wear distribution, with maximum instantaneous stress at characteristic points A and B—stress at A reflects liner impact degree, while stress at B indicates mill ore-crushing capacity. Optimizing flat liner shape adjusted wear rate peaks (M^a, M^b), improving overall liner wear. This optimization significantly affected stresses at A/B and ore normal collision but had little impact on mill energy efficiency. Full article

The thermal transformation mechanism of pyrite in coal, which governs sulfur emissions and ash deposition, remains highly controversial. There are significant discrepancies in reported activation energies (E_a) (60–310 kJ/mol) and conflicting reaction pathways. To resolve these long-standing controversies, this study proposes a competition-coupling mechanism: pyrolysis and oxidation compete under local O₂ and temperature gradients, while coupling through microstructural evolution. Specifically, pyrolysis generates a porous Fe_1−XS that facilitates oxidation, which in turn can form a passivating oxide/sulfate layer that promotes further pyrolysis. This mechanism reconciles longstanding kinetic controversies by showing that the apparent activation energy is not a fixed value but instead a dynamic parameter, shifting along a continuous curve that bridges pyrolysis and oxidation-dominated regimes. Furthermore, we construct a unified phase diagram by incorporating the competition-coupling mechanism into classical thermodynamic equilibria. This diagram uses the molar ratio FeS₂/(FeS₂ + O₂) and temperature to categorize the transformation process into four distinct regions—pyrolysis-dominated, competition-coupling, oxidation-dominated, and melt-dominated. The key contribution of this work lies in the diagram which offers a practical framework for optimizing combustion and roasting systems, allowing for improved control over sulfur emissions and ash-related issues such as slagging and fouling. Full article

Geological Carbon Sequestration (GCS) plays a crucial role in addressing climate change, particularly in oil and gas development. Understanding the reaction of supercritical CO₂ under in situ conditions and its effects on minerals is essential for advancing GCS technology. This study investigates the reaction mechanisms of feldspar (potassium and sodium feldspar) and clay minerals (chlorite, illite, montmorillonite, kaolinite) in CO₂ environments. The impacts on mineral crystal structures, morphologies, and elemental compositions were analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), and ion concentration measurements (ICP-OES and ICP-MS). The results show that feldspar minerals exhibit lower reaction rates, with sodium feldspar dissolving faster than potassium feldspar, due to the higher solubility of sodium ions in acidic conditions. Chlorite showed significant crystal structure damage after 30 days, while montmorillonite underwent both dissolution and precipitation, influenced by interlayer cation dissociation. Kaolinite exhibited minimal reaction, primarily showing localized dissolution. Additionally, the formation of siderite (FeCO₃) was observed as Fe²⁺ substituted for Ca²⁺ in CaCO₃, highlighting the role of iron-bearing carbonates in CO₂ interactions. The study provides insights into the factors influencing mineral reactivity, including mineral structure, ion exchange capacity, and solubility, and suggests that chlorite, montmorillonite, and illite are more reactive under reservoir conditions, while kaolinite shows higher resistance to CO₂-induced reactions. These findings offer valuable data for optimizing GCS technologies and predicting long-term sequestration outcomes. Full article

The Arkansas alkaline province (AAP), southeastern US, consists of seven intrusions or intrusive complexes that lie along a NE–SW trend that falls on the extension of the Mississippi Valley graben. There are three distinct magmatic events: (1) emplacement of lamproites at ~104 Ma, (2) emplacement of lamprophyres, phonolites, carbonatites, ijolites, and a variety of nepheline syenites between 100 and 98 Ma, and (3) emplacement of a large nepheline syenite body at ~88 Ma. Unpublished and published mineralogical, elemental, and isotope data are used to develop an integrated model for the AAP magmatic activity. The lamproites were derived from ancient enriched subcontinental lithosphere. The carbonatite–lamprophyre–phonolite–ijolite–nepheline syenite association comprises several intrusive complexes (Magnet Cove, Potash Sulphur Springs, V-intrusive) and the Benton lamprophyre–felsic dike swarm. Magmatic evolution is controlled by fractional crystallization of pyroxene and nepheline. The carbonatites may be the result of liquid immiscibility between carbonate and lamprophyric liquids. The large nepheline syenite body (Granite Mountain and Saline County) evolved through fractional crystallization of feldspar and nepheline. Event 2 and 3 magmas were derived from an OIB-like asthenospheric source. The most likely model for the origin of the AAP is the reactivation of a zone of crustal weakness by far field stresses. Full article