Search Results (97)

This review paper examines extraction methods in the dimension stone industry. Traditional techniques, like thermal shock, hammer and chisel, and plug and feather, were used historically. However, advancements in technology have led to the adoption of mechanized methods. Diamond wire cutting is a highly efficient technique that reduces waste and ensures quality. Challenges like high costs and wire breakage remain. Circular diamond saws and frame sawing are explored as alternative methods. Stone characteristics influence machinery selection and researchers have studied the impact on extraction efficiency. Controlled blasting with explosives shows promise and requires further exploration and optimization. Full article

Accidents at mining enterprises, including tailing dumps, pose significant threats to human lives, structures, and the environment. This study focuses on designing, constructing, and operating tailing dumps in Siberia’s northern region. To ensure safety and minimize environmental impacts, comprehensive scientific monitoring and research were conducted at all stages, including design, construction, operation, and disposal. The aim was to create a uniform mass within the dam body, requiring understanding of the tailing structure and technological characteristics during placement. Parameters like particle size, distribution, density, and moisture content were considered to assess the physical and geometric properties of the tailings. Estimated monitoring was introduced as a permanent model to quickly assess the stability of hydrotechnical constructions. This involved monitoring changes in exploitation properties, structure height, beach length, and water levels. A controlled inwashing technology for subsequent dam layers was developed. Complex research facilitated the formulation of an estimated monitoring methodology and an algorithm for tailing dam formation. Practical application demonstrated high reliability and confirmed load-bearing capacity, allowing for the forecast of dam stability and safe execution. Findings led to alterations in work techniques, ensuring safe and efficient operation of tailing dams. Full article

This study investigates the transition from surface to underground mining at the Sepon Gold mine. The stability of surface slopes is assessed prior to commencing underground operations. Stope mining is adopted based on ore body characteristics and geological features. Finite element numerical analysis, employing the Generalized Hoek–Brown criterion, evaluates slope stability for surface slopes and opening stopes. The pit design comprises a 70° slope angle, 20 m height, and 10–15 m safety berm, meeting stability requirements with a factor of safety of 2.46. Underground mining design includes a 62° ore body dip, a 50 m thick crown pillar to prevent surface subsidence, and 5 m wide, 5 m high stopes. Sill pillars are left for support after each level of excavation. Rock bolts are employed in specific stope areas where necessary, with continuous monitoring for surface deformation. This study analyzes the influence of stope sizes on the pit wall and pit bottom stability, identifying slope failures near the hanging wall close to the pit bottom during underground mining. A slight increase in the displacement zone is observed on the upper crest of the top footwall. Overall, the findings demonstrate successful stability in the transition from surface to underground mining at the Sepon Gold mine. Full article

Recent laboratory studies have shown that biopolymers have the potential to act as dust suppressants on barren mine soils. However, there is a lack of field trials investigating the effectiveness of biopolymer treatments under real field conditions on a large scale. This study performed field trials to examine the potential of three biopolymers—corn starch (CS), xanthan gum (XG), and fava bean protein concentrate (FBPC)—as dust suppressants. The field trials started in August 2022 with spraying of low doses of the selected biopolymers on trial areas of an overburden dump at the Inden open-cast lignite mine, Germany. The field trials were conducted over 45 days. They included repeated measurements of dust emissions from soil plots exposed to different airflows generated by an electric blower, visual inspections, and penetrometer tests. The results showed that all biopolymer treatments effectively suppressed dust emissions in the short term up to 8 days after application. Total suspended particle emissions measured on the biopolymer-treated trial plots were significantly reduced and ranged from 0.05 to 0.27 mg/m³ compared to the untreated control (4.5 to 39.2 mg/m³). The visual inspections and penetrometer tests supported these results. After day 8, rainfall-induced leaching of the biopolymers resulted in the rapid degradation of the treatments’ effectiveness. The results suggest that the treatments would have lasted longer under dry conditions. Thus, the field trials provide practical evidence that biopolymers can effectively mitigate dust emissions on exposed, undisturbed mine soils in the short term, making them a bio-based alternative to traditional dust suppressants, such as chloride salts or petroleum-based products. Full article

Landform evolution modelling (LEM) provides an avenue for simulating how a landscape may evolve over extended time periods of thousands of years. CAESAR-Lisflood LEM which includes a hydrologic model (TOPMODEL) and a hydraulic model (Lisflood) can be used to assess the proposed final landform morphology of a mine site by simulating how the mine landform and the landscape would evolve over a 1000-year period. The accuracy of future simulations depends on the calibration and validation of the model to past and present events. Calibration and validation of the model involve finding a combination of parameters of the model which when applied and simulated gives model outputs similar to those observed for the real site scenario for corresponding input data. Calibrating the sediment output of the CAESAR-Lisflood model at the catchment level and using it for studying the equilibrium conditions of the landform is an area that has yet to be explored. Therefore, the aim of this study was to calibrate the CAESAR-Lisflood model and then validate it. To achieve this, the model was run for a rainfall event with a set of parameters, plus discharge and sediment data for the input point of the catchment, to analyse how similar the model output would behave when compared with the discharge and sediment data for the output point of the catchment. The model parameters were then adjusted until the model closely approximated the real site values of the catchment. The model was then validated by running it for a different set of events and checking that the model gave similar results to the real site values. The outcomes demonstrated that while the model can be calibrated to a greater extent for hydrology (discharge output) throughout the year, sediment output calibration may be slightly improved via the ability to change parameters to take into account the seasonal vegetation growth during the start and end of the wet season. This study is important for designing and testing post-mining rehabilitated landscape systems that assess hydrology and sediment movement in seasonal biomes. Full article

Salt caverns produced by solution mining in Southern Ontario provide ideal spaces for gas storage due to their low permeability. Underground hydrogen storage (UHS) is an important part of the future renewable energy market in Ontario in order to achieve global carbon neutrality and to fill the gap left by retiring nuclear power plants. However, large-scale hydrogen storage is still restricted by limited storage space on the ground’s surface. In this study, hydrogen’s physical and chemical properties are first introduced and characterized by low molecular weight, high diffusivity, low solubility, and low density. Then, the geological conditions of the underground reservoirs are analyzed, especially salt caverns. Salt caverns, with their inert cavity environments and stable physical properties, offer the most promising options for future hydrogen storage. The scales, heights, and thicknesses of the roof and floor salt layers and the internal temperatures and pressures conditions of salt caverns can affect stabilities and storage capacities. Finally, several potential problems that may affect the safe storage of hydrogen in salt caverns are discussed. Through the comprehensive analysis of the influencing factors of hydrogen storage in salt caverns, this study puts forward the most appropriate development strategy for salt caverns, which provides theoretical guidance for UHS in the future and helps to reduce the risk of large-scale storage design. Full article

The greatest challenges for contemporary and future natural resource production are sociotechnical by nature, from public perceptions of mining to responsible mineral supply chains. The term sociotechnical signals that engineered systems have inherent social dimensions that require careful analysis. Sociotechnical thinking is a prerequisite for understanding and promoting social justice and sustainability through one’s professional practices. This article investigates whether and how two different projects enhanced sociotechnical learning in mining and petroleum engineering students. Assessment surveys suggest that most students ended the projects with greater appreciation for sociotechnical perspectives on the interconnection of engineering and corporate social responsibility (CSR). This suggests that undergraduate engineering education can be a generative place to prepare future professionals to see how engineering can promote social and environmental wellbeing. Comparing the different groups of students points to the power of authentic learning experiences with industry engineers and interdisciplinary teaching by faculty. Full article

Integrated Optimization can find optimized solutions for a project to define open pit and mine scheduling with greater reliability. This work aims to demonstrate how the insertion of geometallurgical variables can significantly change the financial return of a project. Two geometallurgical variables are considered in mine planning simulations. Specific energy corresponds to the energy consumed in the comminution of the ore, and process recovery measures the percentage of metal incorporated into the product. Three scenarios were developed considering an iron ore deposit. In the Base Case (BC) scenario, the recovery was fixed, and the specific energy of comminution was not considered. GeoMet1 considers the variable recovery varying for each block. GeoMet2 considered both recovery and specific energy as variables varying for each block. GeoMet1 and GeoMet2 presented Net Present Value (NPV), respectively, as 3.68% and 13.57% lower than the BC. This overestimation of the BC results can be viewed as an optimistic case of mine planning that is very common in the mining industry. These results show that the use of specific energy and recovery variables is fundamental to obtaining more reliable mine planning. Full article

In this research, data analytics and machine learning were used to identify the performance metrics of loaders and haul trucks during mining operations. We used real-time collected data from loaders and haul trucks operating in multiple quarries to broaden the scope of the study and remove bias. Our model indicates relationships between multiple variables and their impacts on production in an operation. Data analysis was also applied to ground engagement tools (GET) to identify key preventative maintenance schedules to minimize production impact from capital equipment downtime. Through analysis of the loader’s data, it was found there is an efficient cycle time of around 35 s to 40 s, which yielded a higher payload. The decision tree classifier algorithm created a model that was 87.99% accurate in estimating the performance of a loader based on a full analysis of the data. Based on the distribution of production variables across each type of loader performing in a similar work environment, the Caterpillar 992K and 990K were the highest-yielding machines. Production efficiency was compared before and after maintenance periods of ground engaging tools on loader buckets. With the use of maintenance and production records for these tools, it was concluded that there was no distinguishable change in average production and percentage change in production value before and after maintenance days. Full article

Mining-induced subsidence can have significant environmental and infrastructural impacts, making subsidence engineering a crucial consideration. However, the unique nature of salt caverns and the increasing demand for reliable subsidence prediction models in the context of energy storage require special attention. This study provides a comparative analysis of existing prediction models and highlights their advantages and disadvantages to determine the most appropriate approach. The study primarily focuses on theoretically developing an empirical influence function for asymmetrical subsidence prediction. It significantly contributes to the field by correcting and extending the existing method, providing a generalized solution applicable to any type of asymmetrical distribution around the cavern. Future research directions include implementing the proposed model in relation to real-world data. The insights gained from this study can help advance subsidence prediction models in the field of salt cavern energy storage, addressing a significant need in the industry. Full article

Blasting operations in open-pit mines generally have various management strategies relating to flyrock. There are empirical models for calculating the flyrock distance, but due to the complexity and uncertainty of rock properties and their interactions with blasting properties, there are still no models that can predict the flyrock distance that may be applicable across mining operations in general. In this regard, the Jajarm bauxite mine complex was used as a case study. The purpose of this study was to develop and evaluate different methods that can predict flyrock distance. For this purpose, soft computing models were developed using generalized regression neural network (GRNN), gene expression programming (GEP) and genetic-algorithm-based GRNN (GA-GRNN) methods. To obtain statistical models, multivariable regression was applied in the form of linear and nonlinear equations. A flyrock index was introduced using a classification system developed by incorporating fuzzy decision-making trial and evaluation methods (fuzzy DEMATEL). In order to achieve this goal, the data of 118 blasts in eight mines of the Jajarm bauxite complex were collected and used. Following this, four performance benchmarks were applied: the coefficient of determination (R²), variance accounted for (VAF), root-mean-square error (RMSE) and mean absolute percentage error (MAPE). The performance of the models was evaluated, and they were compared with each other as well as with the most common previous empirical models. The obtained results indicate that the GA-GRNN model has a higher performance in predicting the flyrock distance in actual cases compared to the other models. At first, data on factors that were the main cause of flyrock (and had a direct impact on it) were collected and classified from different blasts. Then, using the collected data, 19 different combinations were established, which can be used to provide the appropriate predictive equation. The purpose of this work is to more accurately predict flyrock and prevent heavy damage to buildings and mining machines across the mining complex. Full article

With the understanding that the mining industry is an important and necessary part of the production chain, we argue that the future of mining must be sustainable and responsible when responding to the increasing material demands of the current and next generations. In this paper, we illustrate how concepts, such as inclusiveness and the circular economy, can come together in new forms of mining—what we call inclusive urban mining—that could be beneficial for not only the mining industry, but for the environmental and social justice efforts as well. Based on case studies in the construction and demolition waste and WEEE (or e-waste) sectors in Colombia and Argentina, we demonstrate that inclusive urban mining could present an opportunity to benefit society across multiple echelons, including empowering vulnerable communities and decreasing environmental degradation associated with extractive mining and improper waste management. Then, recognizing that most engineering curricula in this field do not include urban mining, especially from a community-based perspective, we show examples of the integration of this form of mining in engineering education in first-, third- and fourth-year design courses. We conclude by providing recommendations on how to make inclusive urban mining visible and relevant to engineering education. Full article

This work aims to prepare and characterize the unburned carbon obtained from gasification residues and evaluate its application as an adsorbent for the removal of textile dye contaminants. The results of physical and chemical properties showed a specific mass of 2.05 g/cm³, surface area of 23.983 g/cm², and diameter and pore volume of 0.844 nm and 2.262 cm³/g, respectively. These properties, along with the point of zero charge and chemical bonds present on the surface, favored the adsorption of cationic dyes. The adsorption results showed great potential for the removal of methylene blue, crystal violet, and basic fuchsin if compared with bromocresol green, and indigo carmine. The maximum removal values obtained for methylene blue were up to 99% and the kinetic adsorption was faster at the beginning of the process, reaching the equilibrium in less than 5 min. The results obtained through the adsorption isotherms showed a maximum adsorption capacity of 333.33 and 476.19 mg/g, at the temperature of 291 and 328 K, respectively. The satisfactory results showed that the use of unburned carbon is a cost-effective and eco-friendly alternative to reusing the residue from gasification and also contributes to the decontamination of watercourses. Full article

Here, we present a numerical model for simulating the formation and evolution of the gas and dust cloud that forms after the detonation of high explosive charges in boreholes. This model provides a possible method for converting a substance ejected from an explosion funnel into discrete particles (smaller particles and stones) and calculating the movement of these condensed particles and their interaction with the air–gas flow; this method uses the framework of equations for multiphase media motion. For modeling of borehole explosion, we focused on the parameters of commercial blasting that are carried out at the Lebedinsky open pit. The results of simulating the initial stage of a borehole explosion with a mass of 1000 kg are presented in this paper. These results demonstrate the evolution of a gas and dust cloud, the change in the mass of particles of different sizes in the air over time, and their spatial distribution. Full article

One of the best technologies available for metal removal from mining effluents is the precipitation of metals as sulfides. However, the high cost and difficulty in managing reagents limit its widespread application. Recent literature suggests the use of sulfur-reducing bacteria (S°RB) as a safe and effective alternative to producing H₂S. Nevertheless, direct substrates for S°RB are high-cost low molecular compounds. This research aimed to evaluate the ability to produce sulfides by sulfur-reducing consortia in fixed-bed bioreactors using complex organic substrates. Consortia enriched using cellulose or Spirulina as electron donors were phylogenetically characterized by fluorescent in situ hybridization. Microorganisms belonging to Bacteria and Archaea were involved, being the most representative of the δ-Proteobacterias. The results obtained in test tube culture indicated that these consortia could use cellulose and Spirulina in alkaline conditions, resulting in high sulfide production. Upflowed fixed-bed bioreactors were implemented to establish optimal parameters., resulting in H₂S volumetric productivities ranging from 1.94 to 2.94 mol/m³∙day. In conclusion, an active biomass with significant sulfidogenic activity can be generated in bioreactors under an upflowed regime using cellulose or Spirulina. Full article