فهرست مطالب

Mining and Environement - Volume:14 Issue: 1, Winter 2023

Journal of Mining and Environement
Volume:14 Issue: 1, Winter 2023

  • تاریخ انتشار: 1401/12/06
  • تعداد عناوین: 20
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  • Samir Derouiche *, Khadidja Benoune, Achouak Kenioua Pages 1-11

    The aim of this work is to assess the impact of red clay on the physiological and biochemical alterations in rats exposed to lead acetate. The experimental study was carried out in the laboratory on 18 male Wistar rats, which were divided into three groups of six rats in each, the first group served as control, the second group contaminated with lead, and the third group contaminated with lead and treated with red clay. Some biochemical, haematological, and oxidative stress parameters are analysed. Regarding the characterization of the clay, the results of infrared spectroscopy and X-ray spectroscopy indicate the presence of several bands indicating the mineral richness of red clay. From the analysis of our results, we observe a considerable change in the body weight, and an increase in the relative weight of liver and testis in the rats contaminated with lead compared to control. The results also show a significant decrease (p < 0.001) in the serum calcium and iron. However, serum transaminases (GPT, GOT) activities are increased in the rats contaminated with lead in comparison with control. The results obtained reveal also a decrease in the Hb, HCT, and MCV levels and in the GSH concentration and an increase in the PLT, MDA, GST, and SOD levels compared to control. Also the results clearly show alterations in the structures of the liver and testis in comparison with the controls. Treatment with red clay partially ameliorates the previous parameters, with protection and regeneration of the tissue against free radical attacks caused by lead. In conclusion, this study shows that treatment with red clay induces a positive effect against lead toxicity at molecular and tissue level.

    Keywords: Lead, toxicity, red clay, oxidative stress, Wistar rats
  • Ahmed Abd El-Fatah *, Ahmed Madani, Adel Surour, Mokles Azer Pages 13-31

    The present work aims to enhance the utilization of Landsat-8 data in geological mapping when they are paired with spectroscopic measurements and field observations. This is applied to map and differentiate the different plutonic rocks in the Gebel El-Bakriyah pluton, a peculiar igneous body in the central Eastern Desert of Egypt. Therefore, we use a combination of remote sensing techniques such as principal component analysis (PCA), band ratios, fusion technique, and spectroscopic measurements to interpret igneous lithologies, and produce a new geologic map of the Gebel El-Bakriyah area. A false-color composite principal component image PC1, PC2, and PC3 in red, green, and blue (RGB) discriminates between alkali feldspar granite, syenogranite, and younger gabbro. In general, the spectral profiles of granites exhibit three distinct absorption features in the 1.4, 1.9, and 2.2 μm wavelength regions. These features are attributed mainly to altered mineral products such as kaolinite, sericite, and chlorite. The spectral profiles of pink and alkali feldspar granites show a broad absorption feature at 0.9 μm, which is attributed to a considerable Fe content. The spectral profiles of fresh, younger gabbros exhibit absorption features around 1 μm and 2.2 μm. A false-color composite image provides the most accurate discrimination of the three varieties of younger granites with band ratios of 7/4, 6/3, and 3/1 in RGB. The data that appear in the present work strengthen the usefulness of Landsat-8 imagery and spectroscopic measurements as a prevailing grouping to discriminate and map Neoproterozoic shield rocks in the Eastern Desert of Egypt.

    Keywords: Gebel El-Bakriyah ring complex, Younger granite, Younger gabbro, Landsat-8, Sentinel-2, Spectroscopy
  • Edith Amoatey *, Eric Glover, David Kpeglo, Francis Otoo, Dennis Adotey Pages 33-46

    Knowledge of accurate radio-isotopic signatures of NORM waste disposal site is essential prior to the disposal, to ascertain the baseline radioactivity levels. In this work, soil and water from a NORM waste site situated at Sofokrom in the Sekondi-Takoradi Metropolis of Ghana is characterized and determined. The mean activity concentration of 226Ra, 232Th, and 40K measured in the soil samples are 40.31 ± 13.93 Bq/kg, 63.29 ± 23.18 Bq/kg, and 198.71 ± 49.10 Bq/kg, respectively, with the 226Ra and 232Th average values being higher than the average worldwide values by UNSCEAR. Also, the average activity levels of water samples from monitoring borehole measured for 226Ra and 232Th are within the WHO guidance levels of 1 Bq/L. The radiological parameters such as internal and external hazard indices (Hin and Hex), absorbed dose rate (D), and radium equivalent activity (Raeq) are estimated to assess the radiological risk to human, and compared with other similar works.  Except for the annual gonadal dose, the remaining parameters are less than the recommended values. Multivariate statistical analysis is done to establish the interrelations among the activity concentrations of the radionuclides and their radiological parameters using Pearson correlation coefficient and principal component analysis. Strong positive correlations between 226Ra, 232Th, and the radiological parameters are observed. These findings would serve as the reference point for assessing future variations in the background radioactivity level owing to the geological or human activities from the disposal of the oil waste in the environment, as well as to aid in improving the technical foundations for the management of the NORM waste.

    Keywords: Radiological Parameters, Oil Waste, Surface Burial, multivariate analysis
  • Pankaj Rathore *, Suresh Tiwari Pages 47-65

    The main aim of this experimental analysis is to understand the effectiveness of ceramic waste (CW) in stabilizing the clayey soil. The effect of adding various CW percentages (5%, 10%, 15%, 20%, 25%, and 30%) on the geotechnical properties of clayey soil is evaluated by performing a series of laboratory tests like the Atterberg’s limit test, compaction test, unconfined compressive strength (UCS) test, California bearing ratio (CBR) test, and swelling pressure test. Micro-structural analysis including scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), and Fourier transform-infrared (FT-IR) spectroscopy are carried out on untreated and treated clay-ceramic composites. The results obtained indicate that the incorporation of 30% ceramic waste in clay soil increase the maximum dry unit weight (γmax) from 17.20 kN/m3 (CL + 0% CW) to 18.25 kN/m3 (CL + 30% CW). The unconfined compressive strength of clayey soil increases with the addition of ceramic waste. A maximum UCS of 217 kPa is obtained with 25% ceramic content, beyond which it starts decreasing. Similarly, increasing trend in CBR results is observed with an increase in the ceramic waste content. The increment in CBR is approximately 152% (unsoaked condition) and 142% (soaked condition). At the same time, the addition of ceramic waste in clay soil reduces the Atterberg limits, optimum water content (ωopt), and swelling pressure. “It can be concluded from the experimental study that CW can be used as a sustainable alternative soil stabilizer.

    Keywords: Ceramic waste, Stabilization, Maximum dry unit weight, UCS, Clayey soil
  • Kwang Hyok Kim, Tok Hyong Han, Un Chol Han *, Ryo Myong Hong Pages 66-77

    This paper focuses on a study concerned with estimation of the platform motion at the lower loading station in the Trucklift slope hoisting system with varying profile of track. The TruckLift slope hoisting system is an innovative transport technology for open-pit mines, and considerably accelerates and cheapens transport from mine. When a truck drives onto or drives off the platform at the lower loading station in the Trucklift slope hoisting system with varying profile of track, the platform motion influences the operation of the Trucklift slope hoisting system, and the configuration of inclined rope hitched to the platform is varied. The simulation result by using the ADAMS (Automatic Dynamic Analysis of Mechanical Systems) software shows that the horizontal distance between lower loading station and platform varies when a truck drives onto or off the platform and the initial horizontal distance that is the distance between lower loading station and platform when the winder is applied the brake, can be an important factor in operation of the Trucklift slope hoisting system with varying profile track.

    Keywords: Trucklift slope hoisting system, ADAMS, sagged inclined rope, platform
  • Deemah Mahmoud *, Ahmed Madani, Said Said, Mohamed Yehia, Tamer Nassar Pages 79-96

    The eastern border of the Nile valley south of Cairo is distinguished by numerous springs and associated surface water bodies, e.g. Ain El-Sira, Helwan, and Atfih. Except the latter, all of them were disseminated in urban areas, and were hardly detected by remote sensing data. Thus, studying the surface water of Atfih spring is key to understanding the nature of the east Nile spring system. Change in this surface water has been detected based on the integration between the spatiotemporal analysis of the multi-spectral satellite images and the Modern-Era Retrospective Analysis for Research and Applications (MERRA-2) rainfall data from 1987 to 2019, and the field investigation. The normalized differential water index analysis reveals an increase in the surface area of the Atfih water body by two to three times during the years 2016-2017. The results clarified the relationship between the appearance of the surface water of Atfih spring and rainfall amounts. Another factor controlling the Atfih water body treated in this work is the geological structures. A field survey aided by the processed satellite data revealed the presence of three fault populations: WNW-ESE, E-W to ENE-WSW, and NNE-SSW. The E-W to ENE-oriented faults are the main faults and have a right-lateral strike-slip sense of movement. This fault pattern and Pliocene shale have a substantial impact on the appearance of the Atfih water body. These faults act as a horizontal channel that allows lateral movement of meteoric water through Eocene carbonate, and water recharge occurs at the highly fractured strike-slip transfer zones.

    Keywords: Multi-temporal Landsat Data, Atfih water body, Rainfall storms, Geological structures
  • Sonu Singh *, Vijay Shankar, Joseph Tripura Pages 97-112

    With an emphasis on establishing a connection between electrical and sub-surface hydro-geophysical features of soils, a critical evaluation of electrical resistivity technique applications is conducted in the current work. In order to identify diverse subsurface soil characteristics at different stratifications, the electrical resistivity approach is a widely utilized geophysical method that is extensively adopted in various Earth landforms. The assessment of sub-surface hydro-geophysical features of soils, on the other hand, offers information on the hydrogeological and geological properties including the classification of aquifer types, groundwater pollution, and seismic data. The vast majority of the information compiled in this work may help the researchers better understand some basic fundamental issues relating the hydrogeology.

    Keywords: ERT Survey, Correlations, Soil Properties, Hydraulic Characteristics
  • Rahul Shakya *, Manendra Singh, Narendra Samadhiya Pages 113-131

    An earthquake is a random occurrence that can happen anytime in highly seismic active areas. Therefore, it might happen even when the metro-train is moving. In such a scenario, the vibrations produced by the dynamic loading of a moving metro-train and the dynamic loading due to an earthquake will impact the dynamic response of underground metro-tunnels. In this work, an effort is made to comprehend how the Delhi Metro's underground tunnels will respond to the combined dynamic loading from the earthquake and the running train. Therefore, the dynamic response of underground metro-tunnels is primarily influenced by the vibrations generated due to the dynamic loading of a running metro-train and the dynamic loading due to an earthquake. Both these loadings cause vibrations at the ground surface and the tunnel utilities. In this paper, an attempt is made to understand the response of Delhi metro-underground tunnels to the combined dynamic loading due to the earthquake and the train's motion. Two-dimensional and three-dimensional finite element analyses are carried out using the Plaxis software. The research work finds that the overall response at the ground surface increases due to the combined dynamic loading of the train and earthquake compared to the train's or the earthquake's sole dynamic loading. Maximum displacements in the soil-the tunnel system and forces in RC liners are found to be more significant for the combined loading of the earthquake and the train motion than those due to individual loadings.

    Keywords: Dynamic loading, Underground tunnel, Metro train, Time History, Earthquake
  • Vanshika Bhardwaj, Kanwarpreet Singh * Pages 133-154

    Natural hazards are naturally occurring phenomena that might lead to a negative impact on the environment and also on the life of living beings. These hazards are caused due to adverse conditions of weather and climate events, and also due to certain human activities that are harmful to the environment. Natural hazards include tsunamis, earthquakes, volcanic activity, landslides, etc. Among these natural hazards, landslides are among the most common natural hazards resulting in loss of life and property each year, leading to socio-economic impact; thus to avoid such losses, a comprehensive study of landslides is required. Landslides generally occur in hill region with steep slopes, heavy precipitation, loose shear strength of soil or due to many human activities like afforestation or construction activities. To resolve the problem of landslides in a hilly region, much research is conducted annually, providing a predicted landslide susceptibility zonation (LSZ) mapping of the area of research. The predicted landslide susceptibility maps are verified based on the past landslide data, an area under the curve (AUC), and other methods to provide an accurate map for landslide susceptibility in any area. In this study,93 research articles are reviewed for analysis of LSZ, and various observations are made based on the recent trends followed by various researchers over the world over the past ten years. The study can be useful for many researchers to practice their research on landslide susceptibility zonation.

    Keywords: Landslide, GIS, Landslide Depicting Factors, LSZ Methods, Validation
  • Areeba Qazi, Kanwarpreet Singh * Pages 155-178

    The rock mass classification system is utilized to categorize rocks, and has been used in engineering projects and stability investigations. It focuses on the parameters of rock mass and engineering applications, which include tunnels, slopes, foundations, etc. Rock mass classification is valuable in the areas where the collection of samples and yielding of observation is difficult. With the advancement in technology, various machine-based model algorithms have been used, i.e., ANN and MLR in rock mass classification from prior few years. In the present work, the rock mass classification has been discussed, i.e., rock load, stand up time, RQD, RMR, Q, GSI, SMR, and RMi along with their applications. Considering all the parameters, it is concluded that for slope stability in a poor rock condition, the applicability of GSI is sufficient when compared with RMR. GSI also provides a highly accurate valuation of geo-mechanical properties, making it a valuable tool for the engineers and geologists. Also, the RMR values obtained from the ANN model provide better results for tunnels when compared with MLR and the conventional method. The ARMR classification of Slate, Shale, Quartz Schist, Gneiss, and Calcschist at 5 different locations of the world were 51-54, 66-70, 57-60, 35, 65-70, respectively.  The range for slate and shale was found to be moderately anisotropic, while quartz schist, gneiss, and calcschist were found to be slightly anisotropic and highly anisotropic.

    Keywords: Rock mass classification, Slope Stability, Evaluation, RMR, ANN
  • Blessing Taiwo *, Raymond Aderoju, Olutosin Falade, Yewuhalashet Fissha, O Ogunyemi, A Omosebi, S. Omeyoma, Oluwatomisin Adediran, H Bamidele, Michael Ogundiran Pages 179-196

    Overburden material is typically removed in surface mining operations to expose the primary ore deposit. Because of the presence of trace minerals, environmental pollution and acid drainage are caused when the overburdened materials are removed from the mine site and transported to another location. In order to promote the economic and environmental sustainability of dolomite mining, the waste materials must therefore be evaluated for their environmental impact and potential industrial application. Akoko Edo Nigeria is known for its large production of dolomite and carbonate rock with large tonnage waste. The hydrogeochemical and geotechnical analysis of selected mine in this area is performed by randomly collecting and analyzing soil and water samples from four exploration drill holes using an atomic absorption spectrophotometer. The geotechnical analysis results show that dolomite waste soil is suitable for constriction material addictive such as road subgrade, dam design, highway, and other construction work. According to the study's findings, the mine water is slightly polluted, as measured by both the Overall Index of Pollution (OIP) and the Pollution Load Index (PLI). The chemical analysis of the mine pit water also reveal that the mean value of electrical conductivity, TDS, iron, manganese, copper, and lead all exceed the WHO and SON standards for a safe drinking water. A new pollution assessment model with suitable prediction correlation accuracy (R2= 0.76, mean average error = 0.27) is also developed in this work.

    Keywords: mine waste, soil geotechnical properties, mine water quality assessment, soil geology, construction works
  • Zahra Rezaee Shahzadehaliakbari, Mehran Arian *, Mohsen Pourkermani, Ali Solgi, Anahita Keynezhad Pages 197-216

    The Gazkhizan Copper deposit is located in the Troud-Reshm zone, Central Iran. It is situated in a shear zone bounded by the Anjilo and Troud sinistral strike-slip faults from the north and south, respectively. Mineralization is done by siliceous-shear veins along with copper mineralization. About 41 mapping points carried out around the fault outcrops, along with the interpretation of the Win Tensor software data and geometrical analysis of structural features paved our way to study the Riddle pattern in the region. The structural features include sinistral and dextral strike-slip faults, normal faults, reverse faults (rarely), and mineralized veins, as well as different types of shear zone fractures with different grades of copper ore. The mineralized veins in the area are frequent in four types including the R´, R, T, and X fractures, respectively. The highest number of the veins have been formed within the Riddle fractures. Because of the hybrid nature of the fractures, the veins are formed within the tensile fractures, and then they are aligned along the R fractures’ strike by the clockwise rotations. The importance and necessity of this research work is as what follows. The definitive reserve of this mineralized area is 434,500 tons of copper ore with an average grade of 1.61% of copper. For this reason, it is necessary to determine and classify the fractures that host this reserve.

    Keywords: Gazkhizan mine, Troud, Mineralization, Shear zone, Central Iran
  • Leila Nikakhtar, Shokroallah Zare *, Hossein Mirzaei Pages 217-232

    Surface settlement induced by tunneling is one of the most crucial problems in urban environments. Hence, accurate prediction of soil geotechnical properties is an important prerequisite in the minimization of it. In this research work, the amount of surface settlement is predicted using three-dimensional numerical simulation in the finite difference method and Artificial Neural Network (ANN). In order to determine the real geotechnical properties of soil layers around the tunnel; back-analysis is carried out using the optimization algorithm and monitoring data. Among the different optimization methods, genetic algorithm (GA) and particle swarm optimization (PSO) are selected, and their performance is compared. The results obtained show that the artificial neural network has a high ability with the amounts of R=0.99, RMSE=0.0117, and MSE= 0.000138 in predicting the surface settlement obtained from 150 simulations from randomly generated data. Comparing the results of back-analysis using the optimization algorithm, the genetic algorithm shows less error than the particle swarm algorithm in different initial populations. In all cases of analysis, the calculation time for both algorithms lasts about 5 minutes, which indicates the applicability of both algorithms in optimizing the parameters in mechanized tunneling in a short time.

    Keywords: Back analysis, Flac3D, Artificial Neural Network, Genetic Algorithm, Particle Swarm Optimization
  • Mohammad Omidi Manesh, Vahab Sarfarazi *, Nima Babanouri, Amir Rezaei Pages 233-242

    This work presents the Semi-Circular Bend (SCB) test and Notched Brazilian Disc (NBD) test of shotcrete using experimental test and Particle Flow Code in two-dimensions (PFC2D) in order to determine a relation between mode I fracture toughness and the tensile strength of shotcrete. Firstly, the micro-parameters of flat joint model are calibrated using the results of shotcrete experimental test (uniaxial compressive strength and splitting tensile test). Secondly, numerical models with edge notch (SCB model) and internal notch (NBD model) with diameter of 150 mm are prepared. Notch lengths are 20 mm, 30 mm, and 40 mm.  The tests are performed by the loading rate of 0.016 mm/s. Tensile strength of shotcrete is 3.25 MPa. The results obtained show that by using the flat joint model, it is possible to determine the crack growth path and crack initiation stress similar to the experimental one. Mode I fracture toughness is constant by increasing the notch length. Mode I fracture toughness and tensile strength of shotcrete can be related to each other by the equation, σt = 6.78 KIC. The SCB test yields the lowest fracture toughness due to pure tensile stress distribution on failure surface.

    Keywords: mode I fracture toughness, Discrete Element Method, Shotcrete
  • Amir Mohammad Nasrollahzadeh Bafti, Mohammad Jahani Chegeni *, Ahmad Moghooeinejad, Zahra Manafi Pages 243-258

    Flotation is the most important method for processing sulfide copper ores. Due to the high cost and environmental hazards caused by the chemical reagents used in this process (collectors, frothers, pH regulators, depressants, etc.), the possibility of replacing all these reagents or at least some of them are of special importance through environmentally friendly methods such as bio-flotation using halophilic bacteria. These bacteria have the ability of growth and proliferation in salty media and relatively neutral pHs such as sea salty water. In this research work, the four types of halophilic bacteria Halobacillus sp., Alkalibacillus almallahensis, Marinobacter sp., and Alkalibacillus sp. are studied to replace frothers (MIBC and F7240), depressant (sodium metabisulfite), and pH regulator (lime) in sulfide copper flotation using a Denver laboratory flotation cell. The results obtained indicate that each of the four types of bacteria mentioned above along with collectors (gasoil, Z11, and C7240) as the only chemical reagents (bio-flotation + collector) can depress pyrite better than the bacteria-free mode (flotation + all chemical reagents). Iron recovery in tailings in the standard flotation test is 46.8%, which is, respectively, increased to 91.9%, 74.5%, 70.3%, and 76.9% using the halophilic bacteria of Halobacillus sp., Alkalibacillus almallahensis, Marinobacter sp., and Alkalibacillus sp. On the other hand, the recovery of chalcopyrite using the bio-flotation method is lower than its recovery using the flotation method. Copper recovery in the concentrate in the standard flotation test is 89.1%, which is reached to 58.8%, 71.4%, 62.5%, and 69.4%, respectively, using the above bacteria in the bio-flotation method.

    Keywords: Sulfide copper flotation, Bio-flotation, Halophilic bacteria, Chemical reagents, Pyrite, chalcopyrite
  • Enayatallah Emami Meybodi, Syed Khaliq Hussain, Mohammad Fatehi Marji * Pages 259-276

    In this research work, X-ray diffraction (XRD) tests and petrographic studies are performed to analyze the mineral composition and lamination in the shale rock specimens. Afterward, point load (PL) and uniaxial compressive strength (UCS) tests are carried out on the anisotropic laminated shale rock. Based on the macro-mechanical properties of these tests, the discrete element method implemented in a two-dimensional particle flow code (PFC2D) is adjusted to numerically simulate the shale rock specimens. The aim of this work is to validate the numerical models by failure process, stress-strain curves, and peak failure strengths of the shale samples. Therefore, point load test is used for assessing the pattern failure mechanism, and uniaxial compressive strength test is performed for obtaining the stress-strain curves and peak strength failure points in the laboratory shale rock samples. Validation of peak strengths criteria provides the best results; the determination coefficient values for lab and numerical modeling with (R2 = 0.99). Several numerical models are prepared for estimating the mechanical behavior of shale rocks in PFC2D. The smooth joint model (SJM) is used for preparing the consistent and appropriate constitutive models for simulating the mechanical behavior of laminated shale. It is concluded that SJM provides more reasonable results for laminated shale rock that can be used for several petroleum engineering projects, especially in the central geological zone of Iran.

    Keywords: Shale rock, PFC2D, Delamination, Smooth joint model, Distinct Element Method
  • Sajjad Jannesar Malakooti *, Hadi Abdollahi, Ziaeddin Pourkarimi, Behrouz Karimi Shahraki, Mehdi Rahimi, Mohammadreza Shahbazi, Ahmad Rahmanian Kooshkaki Pages 277-293

    Parvadeh IV and East Parvadeh mines are two main coal-producing zones within the Tabas coalfield, east of Iran. Since studies have shown that C1 and B2 are the most important working seams in the Parvadeh IV and east Parvadeh areas, this research work focuses on these two coal seams. Syngenetic pyrite is available as framboids related to macerals. Decreasing the sulfur content is especially hard when the pyrite particles are fine-grained, finely disseminated, and intergrown with the coal maceral structure. The sulfur content measured in C1 and B2 seams varies from 0.98% to 5.57% and from 0.73% to 5.25%, respectively, with an average of 2.39% and 2.5%. We use a method to predict how coal desulfurized the C1 and B2 seams of Parvadeh IV and C1 seams of east Parvadeh mines in the Tabas coalfield. The results have given new proofs for the presence of pyrite and clay minerals within the coalfield zone, and to identify a method to predict coal desulfurization with conventional processing and cost-effective methods. The coal preparation strategy in MEMRADCO, Parvadeh, and Ehyasepahan coal-cleaning plants not as it expels mineral matter and pyrite but too reduces the content of most inorganic components.

    Keywords: Coal mineralogy, Coal desulfurization, Framboidal pyrite, Coal washing plants
  • Mahsa Khoshfarman Borji, Ahmad Reza Sayadi *, Ehsan Nikbakhsh Pages 295-319

    The iron and steel industry is one of the most resource-intensive and pollutant industries that creates the highest value across all mining and metal industries. While the recent studies provide recommendations to improve sustainable development in this industry, the complexity of the socio-environmental impacts of activities in this industry due to its multi-tier and multi-supply chain structures has given rise to the problem of sustainable steel supply chain network design. This work proposes a new multi-objective mixed-integer linear programming model to integrate sustainability factors with managerial and technical restrictions. The total economic profitability is maximized, while environmental pollution is minimized. There is also a focus on the social and environmental compliance. Accordingly, a novel sustainability assessment system is proposed. The managerial restrictions are also satisfied by maximizing the demand fulfillment priority using a new method. The augmented ε-constraint method is applied to tackle the mathematical problem under study. Finally, a real case study is used. The results obtained 35% and 41% reductions in CO2 and particulate matter emissions, respectively, while the total profit decreases up to 15%. A sensitivity analysis is also performed. In addition, several managerial insights are discussed based on the results.

    Keywords: Iron, steel industry, Supply chain network design, Sustainability assessment system, Demand fulfillment priority, Multiobjective Optimization
  • Mohammad Rezaei *, Navid Nyazyan Pages 321-339

    Rock drilling is one of the most important processes in the mining operations, which involves high costs. Deep knowledge of the drilling conditions and rock mass properties can help the optimum selection of drilling system, precise determination of type and number of drilling equipment, and accurate prediction of drilling rate. The above process leads to enhance the drilling efficiency and mining productivity. In this work, relationships between the rock the physico-mechanical properties and horizontal drilling rate (HDR) are investigated. For this purpose, HDR is firstly measured during the drilling process at the Malawi marble quarry mine, Islamabad-e-Gharb, Iran. Then core samples are prepared from the representative minor rock blocks to conduct the laboratory tests and evaluate the influence of rock properties on HDR. The experimental results prove that natural density (ρn), dry density (ρd), slake durability index (Id), Schmidt hammer rebound (SHR), compression wave velocity (Vp), point load index (PLI), uniaxial compressive strength (UCS), and modulus of elasticity (E) have inverse relationships with HDR. Conversely, HDR has a direct relationship with porosity (n), water content (Wa), Los Angeles abrasion (LAA), and Poisson ratio (ν). Generally, it is proved that HDR is more associated with the rock's physical properties than the mechanical characteristics. Moreover, sensitivity analysis confirm that n and ρd are the most and least effective variables on HDR. Furthermore, new optimum empirical equations with acceptable accuracy are proposed to predict HDR based on the statistical modeling. Finally, experimental verification analysis confirm the superiority of this study compared to the prior similar studies.

    Keywords: Marble quarry mine, Horizontal drilling rate, Physical Properties, Mechanical Properties, Statistical modeling
  • Hassan Sarfaraz *, Mohadeseh Sarlak, Fatemeh Ashoor, Erfan Amini Pages 341-353

    In rock slopes, block toppling failure is a prevalent instability. In this instability, rock mass consists of a series of dominant parallel discontinuities that are dipping steeply into the slope face, and a series of cross-joints are located normal to the dominant discontinuities. Blocks may slide or rotate due to their weight along the natural cross-joints at their base, and the tensile strength does not significantly affect the stability of the rock slope. The rounding edge of rock columns is a special feature of spheroidal weathering. Firstly, a literature review of block toppling instability is presented. Next, applying the Sarma approach, a new theoretical analysis is proposed for the rock columns with rounded edges. One of the advantages of the proposed approach is that by determining the sign of a parameter called KC, the stability status can be specified. The suggested solution is compared with a pre-existing analytical method through examples and case study. Comparisons indicate that the proposed approach has a satisfactory agreement. It can be concluded that with weathering and rounding of the block edges, the safety factor decreases non-linearly. Therefore, this solution can be used to evaluate the blocky toppling failure regarding the erosion phenomenon.

    Keywords: Rock Slopes, Block Toppling, Theoretical Approach, Sarma Methodology, Safety factor