2026-03-12
Davood Mohammadi Sargini, Mohammad Ataei, Reza Mikaeil, Akbar Esmaeilzadeh
One of the most important economic sectors is mining. Open-pit mines are the most common form, and blasting is the most efficient method. This method can cause significant damage due to vibrations. Thus, monitoring and controlling vibrations is important. This research aims to predict vibrations based on the distance and quantity of explosives. To study this, vibrations were estimated using Peak Particle Velocity from seismograph devices. Measurements were done in two large Iranian mines, providing approximately 1000 data points. Considering the data complexity, a deep learning method was selected for modelling. Deep learning has numerous hyperparameters, and their correct adjustment impacts efficiency. The Coronavirus Herd Immunity Optimizer (CHIO) was used to find optimal values. Various criteria were used to test the model efficiency. The results indicate the optimization method improved predictions by at least 4%. The coefficient of determination for random forest, basic deep learning, and optimized methods was 0.861, 0.932, and 0.972. The root means square error values are 3.687, 2.338, and 1.146. The absolute mean percentage error indices are 0.169, 0.128, and 0.068. It is concluded that deep learning has acceptable performance. Its efficiency can be increased by optimization algorithms. The results show an excellent response to the integration of the CHIO method, demonstrating its good capability.
2026-03-12
Suharsono Suharsono, Yustisio Dianwiyono, Edy Wijanarko, Wahyu Hidayat, Muhammad Fachrul Rozi Kurniawan, Yudha Agung Pratama
The Pamaluan Formation, which has a Total Organic Carbon (TOC) value of up to 1.78% and varying degrees of thermal maturity, offers the Indonesian Kutai Basin considerable potential for shale gas production. This research integrates seismic and magnetotelluric (MT) geophysical techniques to improve the knowledge of shale gas prospectivity in the area. There are nine MT sounding locations and nine 2D seismic lines in the dataset. By creating a time structure map, the anticline and syncline structures that were detected by seismic interpretation were further examined. 2D resistivity inversion models were created by processing MT data using the rho variance approach and the Python WALDIM module. A dominant anticline-syncline structural trend oriented roughly 45° from true north is indicated by the data. With an average strike of 43.5°, MT analysis demonstrates a dominant two-dimensional (2D) geoelectrical dimensionality that is in good agreement with local geological trends. At depths of 500–1000 m in anticlines and 2000–3000 m in synclines, zones of low resistivity (1–5 Ohm.m) were found, with thicknesses varying from 2000 to 4000 m. Low resistivity anomalies are interpreted to represent potential shale gas-bearing intervals, consistent with the geological framework of the Kutai Basin. The integration of seismic and MT data successfully delineates folds, faults, and low-resistivity anomalies, interpreted as potential shale gas-bearing intervals, highlighting the significance of a multidisciplinary approach in mitigating exploration risk and enhancing shale gas prospectivity evaluation in the Kutai Basin.
2026-03-12
Ekin Koken
This study presents two objective evaluation tools for assessing the feasibility of granitic rocks in dimension stone applications. The developed methods integrate fundamental physical and mechanical properties, including dry density (ρ d ), effective porosity (n e ), P-wave velocity (V p ), uniaxial compressive strength (UCS), and Böhme abrasion value (BAV). Feasibility analyses based on the conditional formatting (CF) and ranking method RM reveal that the adopted input parameters are essential for determining the suitability of granitic rocks as dimension stones. The strong relationship between the CF and RM results highlights their consistency and broad applicability. Both methods exhibit good agreement with the recommendations of the American standard for granitic rocks. Consequently, the suggested methods provide practical guidance for selecting suitable rock exposures in field studies, also offering a time- and energy-efficient decision-making framework for the dimension stone industry. To comprehensively evaluate the strengths and limitations of the proposed approaches, it is recommended that these tools be applied to a wider range of dimension stone types and geological settings.
2026-01-27
Vasyl Karabyn, Iryna Kochmar, Oksana Karabyn, Clint Sutherland, Valentyna Loboichenko, Andrii Khorolskyi
Coal-mining waste heaps represent a significant source of dissolved salts that can be mobilised by precipitation, posing risks to ecological safety and civil protection. This study focuses on the Chervonohrad Central Concentration Plant spoil heap in western Ukraine, where both thermally altered and unaltered argillite were tested. Laboratory column experiments were performed on 100 g samples flushed with deionised water to simulate leaching under controlled conditions. The cumulative leachate volumes reached approximately 432 L, allowing quantification of total dissolved solids and ion-specific contributions. We flushed 100 g columns for 24 h at 300 mL·min⁻¹ (8.5 L recirculated; ≈ 432 L passed), which yielded final filtrate total dissolved solids of 462 vs. 185 mg·L⁻¹ for burnt and unburnt argillite and cumulative leached masses of 3.93 vs. 1.57 g (≈ 2.5× higher for burnt). Early-time contrast was also strong: after 2 h (≈ 0.7 L), burnt reached 183 mg·L⁻¹ vs. 50 mg·L⁻¹ (≈3.7×). Physical observations were combined with a mathematical modelling approach to establish a precipitation-response relationship linking annual rainfall to total dissolved solids release. The results indicate a strong linear increase of annual salt release with precipitation, with burnt materials exhibiting markedly higher fluxes. This integrated framework demonstrates how laboratory data and simple models can be applied to anticipate pollutant releases, supporting ecological safety and informing civil protection measures in coal-mining regions prone to hydrological extremes.
2026-01-27
Hamdi Rifai, Rizaldi Putra, Wilda Febi Rahmadhani, Nilam Sari, Dessupri Niarti, Wardina Nasution, Erni Erni, Christopher M. Wurster
Cave sediments are essential as they preserve valuable archives of past environmental and climate conditions that physical and chemical measurements can reveal. In this study, we explore the magnetic characteristics of the cave sediments collected from Solek Cave, West Sumatra, Indonesia to understand environmental processes within the cave. We employed rock magnetic methods, including magnetic susceptibility, isothermal remanent magnetization (IRM), anhysteretic remanent magnetization (ARM), and Curie temperature measurements. Additionally, we used X-ray diffraction (XRD) and scanning electron microscopy (SEM) in order to analyze the magnetic mineralogy and morphology of the cave sediments. The results show a high concentration of magnetic minerals, specifically ferrimagnetic groups, indicated by high magnetic susceptibility ranging between 210.7 and 1301.2 × 10 -8 m 3 /kg, with a mean value of 602.7 × 10 -8 m 3 /kg. The calculated χ FD (%) values ranged from 0.2 to 6.6, mostly less than 2%, indicating coarse-grained, multidomain ferrimagnetic minerals. Moreover, results from IRM, ARM and XRD show that the magnetic minerals are dominated by coarse-grained magnetite with a grain size of around 20 to 110 μm. Curie temperature measurements also exhibit various titanium proportions, forming a titanomagnetite phase. The morphology and chemical compositions of the magnetic minerals, determined by SEM and energy-dispersive X-ray spectroscopy (EDS), also support the previous analyses, showing that titanomagnetite is the dominant phase, characterized by coarse grain size and angular shape. The uniformity of the magnetic characteristics and mineralogy suggests a titanomagnetite mineral source likely driven by lithogenic processes such as erosion and fluvial events.
2026-01-27
Andri Kurniawan, Nicolas Silaen, Khalil Ibrahim, Arsy Nurrochman, Ridho Destawan, Nanda Hanyfa Maulida, Irfan Prasetyo, Ahmad Zaenudin, Adhi Wibowo
The February 15, 1994 Mw 6.8 Liwa earthquake ruptured the southern Great Sumatran Fault (GSF), yet its static stress legacy and relation to subsequent seismicity remain weakly quantified. We integrate high-precision double-difference relocation with Coulomb failure stress (ΔCFS) modelling to evaluate post-1994 stress transfer along the Semangko sector. Using ~16,000 P/S picks and identical inversion settings, we test two 1-D velocity models; CRUST1.0 yields near-zero, narrow differential-time residuals (± 0.3–0.4 s) compared with broader heavy tails for AK135 (± 0.7–0.8 s) and are adopted for the final catalogue. Since phase archives are sparse before 2010, events from 1994 – 2009 are treated as background, whereas 2010–2024 earthquakes are relocated; quality control retains 416 events. Relocation suppresses the artificial ~10 km depth band and collapses epicenters into coherent clusters that delineate the West/East Semangko Faults and Semangko Bay. ΔCFS was computed for depths of 5–20 km and μ′ = 0.2–0.8. All scenarios produce the expected four-lobed right-lateral pattern with maxima >0.10 MPa around WSF-B, ESF-A, and the Kumering Fault. Relocated events preferentially occupy positively loaded regions: ~74% fall at ΔCFS > 0 and ~73% at ΔCFS ≥ 0.01 MPa (10 kPa), robust to μ′ and depth. The results indicate unresolved post-1994 loading on multiple Semangko branches and adjacent segments, highlighting the potential for cross-segment triggering. We advocate expanding seismic or geodesy monitoring and targeted paleoseismic surveys in the Semangko–Kumering corridor to refine recurrence estimates and update physics-based hazard models for southern Sumatra.
2026-01-27
Tyto Baskara Adimedha, Roni Cahya Ciputra, Frederikus Dian Indrastomo, I Gde Sukadana, Heri Syaeful, Yoshi Rachael
The Melawi region in Indonesia has been identified as a metamorphic-hosted uranium deposit. The occurrence of sedimentary formations in the downstream area suggests the potential for sandstone-type uranium deposits. Previous studies have concentrated on metamorphic-hosted mineralization, resulting in limited exploration of the sedimentary rocks. Geographic Information System (GIS) technology offers valuable support for mineral prospectivity analysis, including uranium exploration. Among various techniques, fuzzy logic has been demonstrated to be effective in generating prospectivity maps to guide uranium resource development. This research aims to develop a prospectivity map for a sandstone-type uranium deposit in the Melawi region. A GIS-based analysis is performed using available spatial datasets, including geological maps, digital elevation models, and uranium occurrences in Melawi. These datasets served as input for constructing a fuzzy logic model based on the genetic model of sandstone-type uranium deposits. The datasets were reclassified, assigned suitability scores, and operated within a fuzzy logic framework to generate a prospectivity map. The results indicate that 36.64% of the Melawi area is high prospectivity zones, 25.34% is medium prospectivity zones, and 38.02% is the low prospectivity zones. The northern part of Melawi exhibits the most favourability for sandstone-hosted uranium mineralization. This study demonstrates fuzzy logic as a practical tool to delineate the favourable area of a sandstone-type uranium deposit in Melawi. Nevertheless, incorporating more diverse spatial datasets and implementing systematic field validation is necessary to locate uranium deposits accurately.
2026-01-01
Izabella Rebeka Márkus, Gábor Mucsi, Ádám Rácz
This preliminary study investigates the influence of post-magmatic alteration on the breakage behaviour of andesitic rocks during comminution, with particular emphasis on the Chemical Index of Alteration (CIA) and smectite content. Six representative samples from two Hungarian quarries (Recsk and Tállya) exhibiting broadly similar mineralogical and textural properties but varying degrees of alteration were subjected to single particle breakage tests across multiple size fractions. Although the limited dataset does not allow for broad generalisation, the results provide a first indication that increased CIA values and higher smectite contents are associated with greater fragmentation susceptibility, as reflected by elevated A×b parameters. The study demonstrates that alteration indices can provide valuable predictive information on breakage response in andesitic rocks. These findings suggest the importance of integrating alteration metrics alongside traditional mineralogical and textural parameters when evaluating the breakage behaviour of andesitic rocks for aggregates production. While smectite quantification highlights the role of secondary phyllosilicate minerals in reducing the strength of andesitic rocks, CIA offers a more broadly applicable measure of alteration intensity that may be transferable across different volcanic contexts. The results are presented as a case study that highlights the potential of CIA and smectite quantification as predictive tools, while acknowledging the need for further research with larger datasets to confirm these trends.
2026-01-01
Alireza Ghorbanifar, Marzieh Hosseini Nasab, Javad Alibabaii, Mohammad Noaparast
This research was conducted to investigate and optimize the comminution circuit of the Arak Company in which bentonite micronized powder is produced. The criterion for evaluating was the optimal performance of grinding systems and the efficiency of the devices, and simultaneous optimization was considered in feed and product sizes, capacity, and energy. In addition to the Bond formula, Morrell and Austin relations, as an innovative approach, have also been employed to study the different parameters such as rotation speed and mill filling percent. In this unit, the main grinding operation is performed by a tube ball mill that is located in a closed circuit with two air separators. The size of the final product is finer than 75 microns, and 48 kilowatt-hours of energy are consumed to produce one ton of bentonite. About 59% of the total plant energy consumption was related to the grinding circuit of tube mill. The size of the tube mill feed was 3500 microns (d 80 ), the percentage of charge and accumulation were 21 and 14% respectively, the average diameter of the steel balls was 60 mm and the relative rotation speed of the mill was 79%. The results showed that the efficiency of the grinding circuit is poor, and it was merely about 30%. By increasing the percentage of charge of the tube mill from 21 to 70%, increasing the size of the mill feed by 7000 microns, using balls with diameter of <40 mm, and reducing the relative rotation to 60%, the efficiency of the grinding circuit can be increased by 50%. It would be noted that about 16% of the coarse particles in tube mill's product are agglomerated pieces. Therefore, reducing this phenomenon will have a direct effect on the reducing energy consumption and increasing grinding efficiency, as well.
2026-01-01
Mohamadali Chamanzad, Majid Nikkhah, Ahmad Ramazanzadeh, Misha Pezeshki, Imandokht Mostafavi
The accuracy of wellbore instability assessment becomes reliable when sufficient geomechanical model data and appropriate failure criteria parameters are used. The Hoek-Brown failure criterion is widely used in wellbore instability analysis; however, limited focus has been given to parameter determination and the specific conditions for its application (intact rock or rock mass) within wells. In this study, theoretical wellbore analysis was conducted using various failure criteria, with a primary focus on comparing the Hoek-Brown criterion for both intact rock and rock mass conditions. A geomechanical model was developed using petrophysical logs, laboratory tests, and downhole measurements. The geomechanical units of the wellbore were determined through clustering algorithms, supported by downhole plugs. Natural discontinuities within the wellbore were identified using image logs, and their distribution was mapped for each geomechanical unit. The parameters for intact rock in the Hoek-Brown criterion were derived from laboratory test results, while those for the rock mass condition were determined using the rock mass rating (RMR) and geological strength index (GSI). The results indicate that applying the Hoek-Brown criterion assuming intact rock does not provide a reliable estimation of wellbore instability. However, by using the criterion under rock mass conditions, wellbore failures can be accurately predicted according to the wellbore conditions. Additionally, evaluating the wellbore conditions based on geomechanical units improves the theoretical analysis's accuracy and identifies stable and unstable zones.