Exploitation
J. Gholamnejad; A. Azimi; M.R. Teymouri
Abstract
Stockpiling and blending play a major role in maintaining the quantity and quality of the raw materials fed into processing plants, especially the cement, iron ore and steel making, and coal-fired power generation industries that usually require a much uniformed feed. Due to the variable nature of such ...
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Stockpiling and blending play a major role in maintaining the quantity and quality of the raw materials fed into processing plants, especially the cement, iron ore and steel making, and coal-fired power generation industries that usually require a much uniformed feed. Due to the variable nature of such materials, they even come from the same source and the produced ores or concentrates are seldom homogeneous enough to be directly fed to the processing plant ore furnaces. Processing plants in iron ore mines need uniform feed properties in terms of each variable (in this work, iron phosphorous ratio and Fe content in magnetite phase) grade of ore, and therefore, homogenization of iron ore from different benches of an open pit or ore dumps has become an essential part of modern mine scheduling. When ore dumps are considered as an ore source, the final grade of the material leaving the dump to the blending bed cannot be easily determined. This difficulty contributes to mixing the materials of different grades in a dump. In this work, the ore dump elements were treated as normally distributed random variables. Then a stochastic programming model was formulated in an iron ore mine in order to determine the optimum amount of ore dispatched from different bench levels in open pit and also four ore dumps to a windrow-type blending bed in order to provide a mixed material of homogenous composition. The chance-constrained programming technique was used to obtain the equivalent deterministic non-linear programming problem of the primary model. The resulting non-linear model was then solved using LINGO. The results obtained showed a better feed grade for the processing plant with a higher probability of grade blending constraint satisfaction.
Exploitation
H. Nikoogoftar Safa; A. Hezarkhani
Abstract
In this paper, we aim to present a quantitative modeling for delineating the alteration zones and lithological units in the hypogene zone of Masjed-Daghi Cu-Au porphyry deposit (NW Iran) based on the drill core data. The main goal of this work is to apply Ordinary Kriging (OK) and concentration-volume ...
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In this paper, we aim to present a quantitative modeling for delineating the alteration zones and lithological units in the hypogene zone of Masjed-Daghi Cu-Au porphyry deposit (NW Iran) based on the drill core data. The main goal of this work is to apply Ordinary Kriging (OK) and concentration-volume (C-V) fractal model based on Cu grades in order to separate the different alteration zones and lithological units. Initially, anisotropy was investigated and modeled based on calculating the experimental semi-variograms of the Cu values, and the main variography directions were identified and evaluated. Then a block model of the Cu grades was generated using the kriging, and the estimation obtained for OK was applied to the C-V fractal model. The C–V log–log plot based on the estimation method represents the various alteration and lithological zones via threshold values. The comparison and interpretation of the alteration zones and lithological units based on the C–V fractal modeling proved that the method was acceptable and capable of correctly delineating the alteration and lithological units. Regarding the correlation derived from log ratio matrix (used to compare the geological model with the C-V fractal results), it was observed that Cu values less than 0.4% were obtained for OK overlapped voxels with the phyllic alteration zone by an overall accuracy (OA) of 0.737. The spatial correlation between the potassic alteration zones resulting from a 3D geological modeling and the high concentration zones in the C-V fractal model based on OK indicated that the alteration zone contained Cu values greater than 0.4% with OA of 0.791. Also using this method, trustworthy results were obtained for the rock units.
F. Khorram; O. Asghari; H. Memarian; A. Hoseein Morshedy; X. M. Emery
Abstract
The key input parameters for mine planning and all subsequent mining activities is based on the block models. The block size should take into account for the geological heterogeneity and the grade variability across the deposit. Providing grade models of smaller blocks is more complex and costly than ...
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The key input parameters for mine planning and all subsequent mining activities is based on the block models. The block size should take into account for the geological heterogeneity and the grade variability across the deposit. Providing grade models of smaller blocks is more complex and costly than larger blocks, but larger sizes cannot represent areas with high spatial variability accurately. Hence, a unique block size is not an optimal solution for modeling a mine site. This paper presented a novel algorithm to create an adaptive block model with locally varying block sizes aiming to control dilution and ore loss in Sungun porphyry copper deposit of Iran with a complex geometry characterized by multiple dikes. Three grade block models with different block sizes and simulated by direct block simulation are the inputs of algorithm. The output is a merged block model, assigning the smaller blocks to the complex zones, such as ore-waste boundaries, and larger blocks to the continuous and homogeneous zones of the ore body. The presented algorithm is capable to provide an accurate spatial distribution model with a fewer number of blocks in comparison to the traditional block modeling concepts.
M. Sakizadeh; M. T. Sattari; H. Ghorbani
Abstract
The soil samples were collected from 170 sampling stations in an arid area in Shahrood and Damghan, characterized by prevalence of mining activity. The levels of Co, Pb, Ni, Cs, Cu, Mn, Sr, V, Zn, Cr, and Tl were recorded in each sampling location. A new method known as min/max autocorrelation factor ...
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The soil samples were collected from 170 sampling stations in an arid area in Shahrood and Damghan, characterized by prevalence of mining activity. The levels of Co, Pb, Ni, Cs, Cu, Mn, Sr, V, Zn, Cr, and Tl were recorded in each sampling location. A new method known as min/max autocorrelation factor (MAF) was applied for the first time in the environmental research works to de-correlate these elements before their geo-statistical simulation. The high cross-correlation among some elements, while poor spatial correlation among the others, could have made spectral decomposition of MAFs unstable, resulting in some negative eigenvalues, so it was decided to reduce the dimensionality of the original variables by Principal Component Analysis (PCA). The resultant 6 heavy metals (Cr, Mn, Cu, V, Ni, and Co) were converted to their respective MAFs followed by their geo-statistical simulation using Sequential Gaussian Simulation (SGS) independently. Examination of the cross-variograms of MAFs indicated that the resultant factors had been rigorously de-correlated, especially at zero lag and around ∆ lag distance. Several validation checks including reproduction of variograms in data and normal score space, close matching between distribution of MAFs versus simulated realizations, and reproduction of descriptive statistics and data histograms all confirmed that the data values had been honored by this applied method. The results obtained indicated that this method could reproduce the data values as well as the spatial continuity of heavy metals (e.g. semi-variograms) successfully. In addition, this technique is simpler and more computationally efficient than its equivalent sequential Gaussian co-simulation as fitting a linear model of co-regionalization (LMC) is not required in the data-driven MAF method.
Mineral Processing
S. Mohammadi; B. Rezai; A. A. Abdolahzadeh
Abstract
Geometallurgy tries to predict the instability the behavior of ores caused by variability in the geological settings, and to optimize the mineral value chain. Understanding the ore variability and subsequently the process response are considered to be the most important functions of an accurate geometallurgical ...
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Geometallurgy tries to predict the instability the behavior of ores caused by variability in the geological settings, and to optimize the mineral value chain. Understanding the ore variability and subsequently the process response are considered to be the most important functions of an accurate geometallurgical study. In this paper, the geometallurgical index is presented as a new tool to optimize the mining activities. Geometallurgical index is described as any geological feature that makes a footprint on the process performance of ores. In a comprehensive research work at the Sarcheshmeh porphyry copper mine, the geological features that affect the main process responses including the product grade and recovery and plant’s throughput are subjected to investigation. In the current report, the rock hardness variability in terms of semi-autogenous grinding power index (SPI) and its effects on the mill throughput and energy consumption are presented. Ninety samples are collected based on the geological features including lithology, hydrothermal alteration, and geological structures. The samples are mineralogically characterized using XRD, XRF, and electron and optical microscopy. The Starkey laboratory mill, commercialized by Minnovex, is used to perform the SPI comminution test. The SPI results show a wide range of hardness, varying from 12 to 473 minutes. The correlation between the SPI results and the geological features show that lithology is a key geological feature that defines the hardness variability. In addition, the hydrothermal alteration would be an effective parameter in the period that the plant is fed with a single lithology.
J. Shakeri; H. Amini Khoshalan; H. Dehghani; M. Bascompta; K. Onyelowe
Abstract
In this research work, a comprehensive study is conducted to predict flyrock as a typical and undesirable phenomenon occurring during the blasting operation in open-pit mining. Despite the availability of several empirical methods for predicting the flyrock distance, the complexity of flyrock analysis ...
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In this research work, a comprehensive study is conducted to predict flyrock as a typical and undesirable phenomenon occurring during the blasting operation in open-pit mining. Despite the availability of several empirical methods for predicting the flyrock distance, the complexity of flyrock analysis has resulted in the low performance of these models. Therefore, the statistical and robust artificial intelligence techniques are applied for flyrock prediction in the Sungun copper mine in Iran. For this purpose, the linear multivariate regression (LMR), imperialist competitive algorithm (ICA), adaptive neuro-fuzzy inference system (ANFIS), and artificial neural network (ANN) methods are applied to predict flyrock with effective parameters including the blasthole diameter, stemming, burden, powder factor, and maximum charge per delay. According to the attained results, the ANN model with the structure of 5-8-1, Levenberg-Marquardt as the learning algorithm, and log-sigmoid (logsig) as the transfer functions are selected as the optimal network with the RMSE and R2 values of 5.04 m and 95.6% to predict flyrock, respectively. Also it can be concluded that the ICA technique has a relatively high capability in predicting flyrock, with the LMR and ANFIS models placed in the next. Finally, the sensitivity analysis reveal that the powder factor and blasthole diameters have the most importance on the flyrock distance in the present work.
Ankit Kumar; Ravi Kumar Sharma
Abstract
Granular pile anchor is a new technique that is commonly used to improve the pull-out resistance of expansive soil like soft clay, loose sand, and black cotton soil. Using the Abaqus software, this work presents a numerical investigation to estimate the pull-out capacity of granular pile anchor ...
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Granular pile anchor is a new technique that is commonly used to improve the pull-out resistance of expansive soil like soft clay, loose sand, and black cotton soil. Using the Abaqus software, this work presents a numerical investigation to estimate the pull-out capacity of granular pile anchor in soft clay. By applying a specified displacement of 10% of D (pile diameter) on the granular pile anchor, the effects of length, diameter, angle of inclination (α), and number of GPA at varying spacing values on uplift capacity is examined. Additionally, L/D ratios of both individual and group piles are examined using various variables. The study uses expansive soil and GPA of unit weight 17 kN/m3 and 22 kN/m3, poisson’s ratio of 0.4 and 0.3, modulus of elasticity 4 MPa, and 11 MPa, respectively, for the estimation of uplift capacity. The cohesion value for the expansive clay is 25 kPa, and the angle of shearing resistance for GPA is 36˚. According to the numerical study, both for a single pile and for piles placed in a group, with increases in pile length and diameter, the granular pile anchor's pull-out capability improves. For a pile placed in group the value of the pull-out capacity shows optimum result when spacing (S) is 2.5D. Additionally, the uplift capacity of the granular pile anchor increases with an increase in angle inclination (α) from 0˚ to 10˚, and then decreases from 10˚ to 15˚. The efficiency of GPA is examined, which assists in the choice of the different granular pile anchor parameters.
Environment
Aditi Nag; Smriti Mishra
Abstract
This study examines the revitalization of mining ghost towns (MGTs) through heritage tourism, focusing on sustainability and heritage preservation. The study highlights the transformative potential of heritage tourism in revitalizing these towns, highlighting the economic resilience achieved through ...
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This study examines the revitalization of mining ghost towns (MGTs) through heritage tourism, focusing on sustainability and heritage preservation. The study highlights the transformative potential of heritage tourism in revitalizing these towns, highlighting the economic resilience achieved through diversified local economies and responsible tourism practices. Cultural preservation ensures the endurance of unique identities and cultural legacies, sparking community pride and cultural exchange. Sustainability measures extend beyond heritage preservation, promoting environmental stewardship and long-term ecological well-being. Community engagement, educational initiatives, and responsible tourism practices are crucial in sustaining the heritage of these towns. The implications extend beyond individual communities, offering a model for responsible and sustainable tourism practices with global relevance. The significance of revitalizing MGTs through heritage tourism lies in preserving history, empowering communities, and creating vibrant, sustainable destinations for generations.
A. Salimi; M. Ziaii; A. Amiri; M. Hosseinjani Zadeh
Abstract
Remote sensing image analysis can be carried out at the per-pixel (hard) and sub-pixel (soft) scales. The former refers to the purity of image pixels, while the latter refers to the mixed spectra resulting from all objects composing of the image pixels. The spectral unmixing methods have been developed ...
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Remote sensing image analysis can be carried out at the per-pixel (hard) and sub-pixel (soft) scales. The former refers to the purity of image pixels, while the latter refers to the mixed spectra resulting from all objects composing of the image pixels. The spectral unmixing methods have been developed to decompose mixed spectra. Data-driven unmixing algorithms utilize the reference data called training samples and end-members. The performance of algorithms using training samples can be negatively affected by the curse of dimensionality. This problem is usually observed in the hyperspectral image classification, especially when a low number of training samples, compared to the large number of spectral bands of hyperspectral data, are available. An unmixing method that is not highly impressed by the curse of dimensionality is a promising option. Among all the methods used, Support Vector Machine (SVM) is a more robust algorithm used to overcome this problem. In this work, our aim is to evaluate the capability of a regression mode of SVM, namely Support Vector Regression (SVR), for the sub-pixel classification of alteration zones. As a case study, the Hyperion data for the Sarcheshmeh, Darrehzar, and Sereidun districts is used. The main classification steps rely on 20 field samples taken from the Darrehzar area divided into 12 and 8 samples for training and validation, respectively. The accuracy of the sub-pixel maps obtained demonstrate that SVR can be successfully applied in the curse of dimensional conditions, where the size of the training samples (12) is very low compared to the number of spectral bands (165).
B. A. Mert
Abstract
This paper presents the procedures used for determining and defining the tonnage and grade of the coalfields of Kangal basin from the developed GIS-aided block model. In this work, firstly, all the lithological logs of drill holes and chemical analysis data of core in the basin were analyzed with the ...
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This paper presents the procedures used for determining and defining the tonnage and grade of the coalfields of Kangal basin from the developed GIS-aided block model. In this work, firstly, all the lithological logs of drill holes and chemical analysis data of core in the basin were analyzed with the help of geostatistics, and then the digital raster maps of each one of the attributes such as the thickness, calorific value (LCV), ash content (AC%), moisture content (MC%), and surface maps of lignite seams were mapped in GIS environment. In the second stage, quantities of the overburden and resources with different categories were calculated on the basis of field-based quality and volume queries with the help of the digital maps on GIS platform. As a result, it was estimated that the Kalburçayırı field had a tonnage of 116 Mt of lignite with an LCV of 1308 kcal/kg, the Hamal field had a tonnage of 30 Mt of lignite with an LCV of 987 kcal/kg, and the Etyemez field had a tonnage of 48 Mt of lignite with an LCV of 1282 kcal/kg. Also it was estimated that almost 24,278,151 tons of lignite in the Hamal and Etyemez fields had a quality of less than 950 kcal/kg that could be directly fired without the blending process in the power plant. As a consequence, the Hamal and Etyemez fields should go into production as soon as possible and be fired in the power plant after being mixed with the lignite in the Kalburcayırı field so that they can be redounded to economy.
M. R. Azad; A. Kamkar Rouhani; B. Tokhmechi; M. Arashi
Abstract
Upscaling based on the bandwidth of the kernel function is a flexible approach to upscale the data because the cells will be coarse-based on variability. The intensity of the coarsening of cells in this method can be controlled with bandwidth. In a smooth variability region, a large number of cells will ...
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Upscaling based on the bandwidth of the kernel function is a flexible approach to upscale the data because the cells will be coarse-based on variability. The intensity of the coarsening of cells in this method can be controlled with bandwidth. In a smooth variability region, a large number of cells will be merged, and vice versa, they will remain fine with severe variability. Bandwidth variation can be effective in upscaling results. Therefore, determining the optimal bandwidth in this method is essential. For each bandwidth, the upscaled model has a number of upscaled blocks and an upscaling error. Obviously, higher thresholds or bandwidths cause a lower number of upscaled blocks and a higher sum of squares error (SSE). On the other hand, using the smallest bandwidth, the upscaled model will remain in a fine scale, and there will be practically no upscaling. In this work, different approaches are used to determine the optimal bandwidth or threshold for upscaling. Investigation of SSE changes, the intersection of two charts, namely SSE and the number of upscaled block charts, and the changes of SSE values versus bandwidths, are among these approaches. In this particular case, if the goal of upscaling is to minimize the upscaling error, the intersection method will obtain a better result. Conversely, if the purpose of upscaling is computational cost reduction, the SSE variation approach will be more appropriate for the threshold setting.
S. Kumar Jha; P. Warwade; S. Kumar Mahto
Abstract
This work illustrates the impact of excessive mining on the precipitation trends and ground water condition of the Ramgarh district over a period of 12 years (2007-2018). The Landsat 8 and Landsat TM- 5 data is processed under Arc-GIS in order to compare the LULC maps. Out of 7 classified classes, the ...
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This work illustrates the impact of excessive mining on the precipitation trends and ground water condition of the Ramgarh district over a period of 12 years (2007-2018). The Landsat 8 and Landsat TM- 5 data is processed under Arc-GIS in order to compare the LULC maps. Out of 7 classified classes, the Results obtained indicate the expansion of the mining area, barren land, settlement, and water body by 10.95%, 10.07%, 3.44%, and 0.43%, while a reduction in the forest, fallow, and crop land by 11.24%, 11.31%, and 2.34% respectively. The TRMM 3B43 data is used to trace out the annual precipitation values of 5 selected raster location points through Arc GIS. The annual precipitation under the mining regions (lower Mandu, Ramgarh, Bhurkunda) shows a decreasing trend. The Mann-Kendall test and Sen’s slope estimator method is used in order to evaluate the ground water pattern in the pre- and post-monsoonal conditions. The Mandu block, the densest mining region of the district with the positive Z values of 1.714 and 0.137 in the pre- and post- monsoon period shows a decrease in the ground water level at the rates of 0.103 m/year and 0.017 m/year, respectively. The continuous rise in the mining activities has created an alarming shift of weather pattern and deteriorated ground water table in Ramgarh.
Afrodita Zendelska; Adrijana Trajanova; Mirjana Golomeova; Blagoj Golomeov; Dejan Mirakovski; Nikolinka Doneva; Marija Hadzi-Nikolova
Abstract
The treatment of acid mine drainages is usually based on two basic technologies, active and passive treatment technologies. Whichever acid mine drainage (AMD) treatment method is employed, a neutralizing procedure that raises the water's pH over 7.0 using alkaline agents is required prior to discharge. ...
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The treatment of acid mine drainages is usually based on two basic technologies, active and passive treatment technologies. Whichever acid mine drainage (AMD) treatment method is employed, a neutralizing procedure that raises the water's pH over 7.0 using alkaline agents is required prior to discharge. A comparison of eight different agents (BaCO3, Na2CO3, NaOH, KOH, K2CO3, MgO, CaCO3, and Ba(OH)2) was performed in order to choose the most effective neutralizing agent for acid mine drainage treatment. The experiments were performed using a multi-component synthetic aqueous solution with an initial concentration of 10 mg/L of the Cu, Mn, Zn, Fe, and Pb ions and an initial pH value of 1.9. According to the research, the most effective neutralizing agent for the removal of heavy metals from a multi-component aqueous solution is MgO, while the least effective agent was Na2CO3. The obtained series of effective neutralizing agents for the removal of heavy metals from a multi-component aqueous solution are presented in the work. The effect of the studied concentration of neutralizing agents depends on the neutralizing agents and heavy metals that are used. The percentage of heavy metals removed from aqueous solutions increases along with rising pH values. The consumption of the neutralizing agent decreases as the concentration of the neutralizing agent is increased. In addition, the time taken to achieve pH depends on the agent concentration. In particular, as the concentration of the neutralizing agent increases, the time to reach the pH decreases.
Exploitation
F. Sotoudeh; M. Ataei; R. Kakaie; Y. Pourrahimian
Abstract
In mining projects, all uncertainties associated with a project must be considered to determine the feasibility study. Grade uncertainty is one of the major components of technical uncertainty that affects the variability of the project. Geostatistical simulation, as a reliable approach, is the most ...
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In mining projects, all uncertainties associated with a project must be considered to determine the feasibility study. Grade uncertainty is one of the major components of technical uncertainty that affects the variability of the project. Geostatistical simulation, as a reliable approach, is the most widely used method to quantify risk analysis to overcome the drawbacks of the estimation methods used for an entire ore body. In this work, all the algorithms developed by numerous researchers for optimization of the underground stope layout are reviewed. After that, a computer program called stope layout optimizer 3D is developed based on a previously proposed heuristic algorithm in order to incorporate the influence of grade variability in the final stope layout. Utilizing the sequential gaussian conditional simulation, 50 simulations and a kriging model are constructed for an underground copper vein deposit situated in the southwest of Iran, and the final stope layout is carried out separately. It can be observed that geostatistical simulation can effectively cope with the weakness of the kriging model. The final results obtained show that the frequency of economic value for all realizations varies between 6.7 M$ and 30.7 M$. This range of variation helps designers to make a better and lower risk decision under different conditions.
Avinash Chandan; Abhishek Sharma
Abstract
Due to disposal concerns, an enormous quantity of personal protective equipment (PPE) waste from the COVID-19 pandemic constituted a severe health and environmental risk. During the pandemic, the usage of protective suits increased dramatically raising concerns about how to dispose of them to safeguard ...
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Due to disposal concerns, an enormous quantity of personal protective equipment (PPE) waste from the COVID-19 pandemic constituted a severe health and environmental risk. During the pandemic, the usage of protective suits increased dramatically raising concerns about how to dispose of them to safeguard the environment. This research work uses shredded face masks (SFM) to stabilise clayey soil for sub-grade usage. Shredded face masks are added to clayey soil to investigate consistency limits, compaction characteristics, unconfined compressive strength (UCS), and California bearing ratio (CBR). Laboratory experiments demonstrate that clayey soil geo-technical characteristics such differential free swell, consistency limits, UCS, and CBR values have improved. Based on the CBR results, the IITPAVE software is used to design flexible pavement thickness, which was reduced for various commercial vehicles per day for all combinations. Cost analysis is also done to determine the total cost for a 1000-meter stretch. The results show that addition of SFM to clayey soils strengthen the geo-technical properties of clayey soil as the UCS values increase for all curing periods of 3, 7, and 28 days with a maximum improvement of 64% for 28 days curing for 1% SFM content. Also, the CBR value is found to be increased from 1.96% to 6.72%.
B. Tokhmechi; M. Rabiei; H. Azizi; V. Rasouli
Abstract
A complete and accurate analysis of the complex spatial structure of heterogeneous hydrocarbon reservoirs requires detailed geological models, i.e. fine resolution models. Due to the high computational cost of simulating such models, single resolution up-scaling techniques are commonly used to reduce ...
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A complete and accurate analysis of the complex spatial structure of heterogeneous hydrocarbon reservoirs requires detailed geological models, i.e. fine resolution models. Due to the high computational cost of simulating such models, single resolution up-scaling techniques are commonly used to reduce the volume of the simulated models at the expense of losing the precision. Several multi-scale techniques have also been developed for simulating heterogeneous reservoirs including those in which a limited number of blocks down-scale, i.e. splitting coarse blocks into fine cells around the well-zones in the case of simulation of hydraulic fracturing. In these cases, locally computed basis functions are employed to construct a global solver at a coarse-scale such as wavelet- and kernel-based up-scaling techniques. In this paper, a novel/robust 2D block-ordering system is presented, which enables solving multi-resolution up-scaling fluid flow simulations. The results will be described for a simple model, and fluid flow equations will be developed in order to show the structure of transmissibility matrix. It is confirmed that with a developed block-ordering system not only the accuracy of history match increases but also the CPU time decreases.
Environment
Aditi Nag; Smriti Mishra
Abstract
This review paper delves into the burgeoning cultural phenomenon of dark tourism, specifically exploring its connection with Mining Heritage Towns (MHTs). The paper navigates the intricate interplay between tourism competitiveness and ethical considerations in these sites laden with historical trauma ...
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This review paper delves into the burgeoning cultural phenomenon of dark tourism, specifically exploring its connection with Mining Heritage Towns (MHTs). The paper navigates the intricate interplay between tourism competitiveness and ethical considerations in these sites laden with historical trauma through a meticulous analysis of existing literature, case studies, and ethical frameworks. Dark tourism, characterised by exploring locations associated with tragedy, has emerged as a global trend, prompting a critical examination of its economic, cultural, and ethical dimensions within mining heritage contexts. Drawing on a wide array of sources, this comprehensive review elucidates the challenges confronting managers of heritage sites, shedding light on the complex ethical dilemmas they face. The paper comprehensively analyses the complex relationship between tourism competitiveness and ethical practices. It critically evaluates the impact of dark tourism on MHTs' economic landscape, explores its cultural implications, and delves into the ethical complexities of such visits, enriching academic discourse and offering valuable guidance for practitioners and policy-makers. The study enhances understanding of dark tourism's role in MHTs and advocates for sustainable tourism development, emphasising ethical considerations in shaping the future of these unique and historically significant sites.
O.E. Ifelola
Abstract
Metals are ubiquitous within the earth crust. However, the exceptional high-level concentration of heavy metals in the soil due to natural or anthropogenic activities and the chemical forms in which they exist determine the level of risk they portend to the environment. This work was aimed at determining ...
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Metals are ubiquitous within the earth crust. However, the exceptional high-level concentration of heavy metals in the soil due to natural or anthropogenic activities and the chemical forms in which they exist determine the level of risk they portend to the environment. This work was aimed at determining the background level of the presence of seven priority toxic metals (Cr, Ni, Pb, As, Cd, Cu, Zn) in the chemical phases of the overburden topsoil of a bituminous deposit prior to mining activities through the speciation analysis. The grab samples of overburden topsoil were initially obtained and homogenized to composites based on locations for the subsequent sequential extraction procedure (SEP). The specific physico-chemical properties of the sampled soils were simultaneously determined to complement the SEP inferential analysis. The results obtained showed that most metals were spatially bounded to the Fe-Mn oxides (reducible phase) followed by the organic (oxidizable) and the carbonates phases, respectively. Fractionally, the dominant soil texture in the studied area was sand (55.45%); however, the colloidal organic matter and Fe-Mn oxide phases played the dominant roles in the sorption activities of the selected metals. The soil chemical phase with the least metal pool was the exchangeable (water/salt) soluble fraction. The overall assessment revealed that the geogenic heavy metals in the topsoil posed no threats since a marginal fraction of the metals existed in the bio-available form in non-toxic concentrations in the order of Pb > Zn > Cu, while the potential mobility of metals showed that Zn was preferentially higher than Pb and Cu, respectively.
S. Hryhorovych Nehrii; T. Oleksandrivna Nehrii; H. Viktorivna Piskurska; E. Viktorovych Fesenko; Y. Yevhenovych Pavlov; A. Mykolaiovych Surzhenko
Abstract
In this work, we focus on the technology of stabilizing roof rocks by constructing separate rock supports reinforced with metal grids. Their parameters are specified using the results of physical structural modeling. The reinforced and non-reinforced rock supports with different fractional compositions ...
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In this work, we focus on the technology of stabilizing roof rocks by constructing separate rock supports reinforced with metal grids. Their parameters are specified using the results of physical structural modeling. The reinforced and non-reinforced rock supports with different fractional compositions are arranged and tested. Their initial shapes are similar to rectangular parallelepipeds with the base width-to-length ratios of 1:1, 1:1.5, and 1:2. Their shrinkage is determined by loading the supports regarding the rock particle size and the reinforcement density. Increasing the reinforcement density leads to reducing the linear dimensions without losing load-bearing capacity. It is proved that using the grids conduces the self-wedging of the rock particles. They are most effective at the initial stage of the formation of the load-bearing core. The exponential power dependence of the relative support shrinkage on the grid partitions number is obtained. The bearing core sizes in different supports are determined. For the non-reinforced supports, the core width is about 60% of the initial support width, and for the reinforced ones, it is about 90%. The exponential dependence of the core width-to-height ratio on the number of grid partitions is established. The expression for determining the reinforced support width is obtained. The support stability depends on the smallest initial base size. The size of the rock material has a little effect on the shrinkage. Reinforcement by three metal grids leads to reducing the pliability by 21% and 24% for the supports with the side ratios of 1:1 and 2:1, respectively.
Hafeezur Rehman; Ahmad Shah; Mohd Hazizan bin Mohd Hashim; Naseer Muhammad Khan; Wahid Ali; Kausar Sultan Shah; Muhammad Junaid; Rafi Ullah; Muhammad Bilal Adeel
Abstract
The major factors affecting tunnel stability include the ground conditions, in-situ stresses, and project-related features. In this research work, critical strain, stress reduction factor (SRF), and capacity diagrams are used for tunnel stability analysis. For this purpose, eighteen tunnel sections are ...
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The major factors affecting tunnel stability include the ground conditions, in-situ stresses, and project-related features. In this research work, critical strain, stress reduction factor (SRF), and capacity diagrams are used for tunnel stability analysis. For this purpose, eighteen tunnel sections are modelled using the FLAC2D software. The rock mass properties for the modelling are obtained using the RocLab software. The results obtained show that tunnel deformations in most cases are within the safety limit. Meanwhile, it is observed that the rock mass quality, tunnel size, and in-situ stresses contribute to the deformation. The resulting deformations also affect SRF. SRF depends on the in-situ stresses, rock mass quality, and excavation sequence. The capacity diagrams show that the liner experience stress-induced failures due to stress concentration at the tunnel corners. This study concludes that tunnel stability analysis must include an integrated approach that considers the rock quality, in-situ stress, excavation dimensions, and deformations.
Exploitation
M. Mohseni; M. Ataei; R. Khaloo Kakaie
Abstract
The contamination of ores with wastes or materials of lower than the cut-off grade is referred to as dilution. Dilution is an undesirable phenomenon that, on one hand, reduces the product grade and, consequently, reduces the sales prices and, on the other hand, adds an extra cost to waste production. ...
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The contamination of ores with wastes or materials of lower than the cut-off grade is referred to as dilution. Dilution is an undesirable phenomenon that, on one hand, reduces the product grade and, consequently, reduces the sales prices and, on the other hand, adds an extra cost to waste production. Therefore, studying and evaluating the dilution risk is important in mining, and especially in underground mining. In this work, using a powerful decision-making method, i.e. Multi-Attributive Approximation Area Comparison (MABAC), the dilution risk and ranking it in underground mines are assessed. For this purpose, the most important parameters affecting the dilution in 10 mines of the Venarch manganese mines are first identified and then weighed using the Fuzzy Delphi Analytical Hierarchy Analysis (FDAHP) method. Then using the MABAC method, the dilution risk score for each mine is estimated, and subsequently, various mines are ranked as the dilution risk. Then with the implementation of the Cavity Monitoring System (CMS) and measurement of the actual dilution values, the mines are ranked in dilution. The correct matching of the results of these two rankings indicates that the MABAC method is highly effective in the ranking of the risk. At the end, the risk ranking of the mines is done using the TOPSIS method, and the lack of full compliance with the results of this method with the actual values indicates that the MABAC method is preferable to the TOPSIS method.
Rock Mechanics
Kapoor Chand; Radhakanta Koner
Abstract
In open-pit mine, safety of internal dumps is a significant pointer on the economic perspective of the overall project. It has been found in several studies that unplanned and random deposition of the overburdened material is the main reason for mishaps and failure. The study utilized unmanned aerial ...
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In open-pit mine, safety of internal dumps is a significant pointer on the economic perspective of the overall project. It has been found in several studies that unplanned and random deposition of the overburdened material is the main reason for mishaps and failure. The study utilized unmanned aerial vehicles (UAVs) to map the mine dumps, and the precise 3D geometry of the same was reconstructed to evaluate the safety using numerical methods. A framework is proposed to assess and identify the potential zone of instability in the mine dumps. The study was conducted at the open-pit mine at the Raniganj coalfield of Paschim Bardhaman in West Bengal, India. The study assessed the internal dump safety using a 3D limit equilibrium method and numerical methods. Finally, optimum parameters are suggested for the mine dumps geometry under the prevailing geo-mining conditions of the mine site. The framework proposed here for assessing critical zones in mine dumps is cost-effective, easy to use, quick, and efficient.
Rock Mechanics
Naeem Abbas; Li Kegang
Abstract
The study examined the influence of cohesion, friction angle, and tunnel diameter on stability within engineering and geotechnical frameworks, while considering the consequences of nearby excavations on the overall stability assessment. The results show that a higher angle of internal friction leads ...
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The study examined the influence of cohesion, friction angle, and tunnel diameter on stability within engineering and geotechnical frameworks, while considering the consequences of nearby excavations on the overall stability assessment. The results show that a higher angle of internal friction leads to a decrease in soil stability number and weighting coefficient. Tunnel diameter significantly affects face support pressure, with larger diameters requiring stronger support due to increased stress. Higher friction angles help stabilize tunnel faces and mitigate diameter-related pressure effects. Stress redistribution around the tunnel is significant within 2 meters from the center, transitioning to elastic behavior elsewhere. A safety factor of 1.3 ensures tensile failure prevention in single and twin tunnels. Balanced stress distribution between tunnels with a slight difference is observed under isotropic in-situ stress. Numerical modeling enhances stress estimations and reveals changes during tunnel excavation, weakening the rock mass. Ground reaction curve analysis with support measures shows reduced tunnel convergence after implementation, suggesting support strategies like extended bolts using updated rock mass rating. The study improves tunnel design and stability assessment by comprehensively understanding stress redistribution and support strategies.
A. Ramezanzadeh; M. Hood
Abstract
The first step in mining activities is rock excavation in both mine development and production. Constant pressure for cost reduction and creating an improved/safe work environment for personnel has naturally resulted in increased use of mechanical excavation systems in many mining operations. Also, mechanical ...
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The first step in mining activities is rock excavation in both mine development and production. Constant pressure for cost reduction and creating an improved/safe work environment for personnel has naturally resulted in increased use of mechanical excavation systems in many mining operations. Also, mechanical excavation and mining is more compatible with automation, meaning possibility of reduction in number of people in the active underground mines. This factor plays a major role in selection of mining systems especially considering the dire shortage of skilled labour in the industry. While these systems are an integral part of mining activities in underground soft rock mining (coal, salt, potash, trona etc.), there is a need for developing new approaches and machinery for use in the underground hard rock mining. This paper will offer a review of current and emerging technologies for mechanical hard rock excavation, including disc cutting technology, drag picks, mini-disc, and activated/oscillating disc cutter. A review of general guidelines for assessment of the potentials of new research and development on this topic and evaluation of emerging technologies for a specific mining application will also be offered.
R. Ghavami-Riabi; H.F.J. Theart
Abstract
The massive sulphide deposit at Kantienpan Cu-Zn mine is hosted by volcano sedimentary succession known as the
Areachap Group, in the eastern part of Namaqua Metamorphic Province, South Africa. The deposits were affected by a
complex deformation and metamorphic history and represent ...
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The massive sulphide deposit at Kantienpan Cu-Zn mine is hosted by volcano sedimentary succession known as the
Areachap Group, in the eastern part of Namaqua Metamorphic Province, South Africa. The deposits were affected by a
complex deformation and metamorphic history and represent examples of upper amphibolite to granulite grade
metamorphosed volcanic-hosted massive sulphide (VHMS) deposits. The principal purpose of this research is to
characterise the primary geochemical halo’s related to VHMS deposits in this mine. Lithogeochemical characterization
of the primary haloes is based on borehole samples of the footwall, ore zone and hanging wall successions.
Geochemically, the ore zone and alteration zones at Kantienpan VHMS ore deposit display a high peraluminous ratio
confirming the peraluminous nature of these zones as indicated mineralogically and lithologically. The intervals
identified in sampled borehole core with low CaO and Na2O and with high MgO and K2O contents represent the
alteration zone in the original footwall rocks of the deposit.
