V.F Navarro Torres; G Zamora Echenique; R.N Singh
Abstract
Hydrographically Bolivian Poopó Lake is located in the basin of Desaguadero River and it has over a dozen main tributary rivers and other smaller rivers with lower flow. The mine water discharge from the abandoned and current mining activities polluted these rivers by carrying heavy metals, dissolved ...
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Hydrographically Bolivian Poopó Lake is located in the basin of Desaguadero River and it has over a dozen main tributary rivers and other smaller rivers with lower flow. The mine water discharge from the abandoned and current mining activities polluted these rivers by carrying heavy metals, dissolved and suspended solids which in turn polluted the Poopó Lake which is considered as an important Lake in this area. The present paper deals with the environmental hazards associated with the mining activities with an objective of determining the environmental quality of the Poopó Lake and its tributary rivers, based on physical-chemical analysis of superficial water and sediment samples. The results of the research show that the Poopó Lake water quality can be classified as highly saline, containing high concentration of dissolved or suspended solid, as well arsenic, lead, cadmium, zinc and other heavy metals exceeding the permissible limits of pollutants. Desaguadero River contributed to the Poopó Lake pollution by 70% arsenic, 64% lead, 4.27% zinc and 2.18% cadmium. Other important pollution contributors are Antequera River by 57 % zinc, 32.9 % cadmium and 0.66% lead, and Huanuni River by 61.2% cadmium, 2.23% lead and 34.3% zinc. Vinto foundry, Kori kollo mine and mainly San José mine polluted the Poopó Lake by arsenic and lead through Desaguadero River. Bolivar and Huanuni mines polluted the Poopó Lake by cadmium and zinc through Antequera and Huanuni Rivers. Additionally the mining activities continue to pollute the Poopó Lake by dissolved and suspended solids transporting through Desaguadero, Antequera and Huanuni rivers.
Omid Saeidi; Ahmad Ramezanzadeh; Farhang Sereshki; Seyed Mohammad Esmaeil Jalali
Abstract
This study aims at presenting a numerical model for predicting grout flow and penetration length into the jointed rock mass using Universal Distinct Element Code (UDEC). The numerical model is validated using practical data and analytical method for grouting process. Input data for the modeling, including ...
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This study aims at presenting a numerical model for predicting grout flow and penetration length into the jointed rock mass using Universal Distinct Element Code (UDEC). The numerical model is validated using practical data and analytical method for grouting process. Input data for the modeling, including geomechanical parameters along with grout properties, were obtained from a case study. The effect of rock mass properties such as joint hydraulic aperture, spacing, trace length, orientation and grout properties as yield stress and water to cement, w/c ratio was considered on grout flow rate and penetration length. To illustrate the effect of aforementioned properties, models were constructed with dimensions of 40×20m. A vertical borehole with diameter of 60mm and 10m depth was drilled in a jointed rock media. The results were in a good agreement with analytical method. It was observed that by increasing joint hydraulic aperture, grouting flow increases using a power law function. The optimum grout penetration observed with joint sets intersection of 40°-60° as experienced in practice. With an increase in joint spacing grout penetration increases around borehole when spacing exceeds two meters it decreases, gradually.
M. Capik; B. Batmunkh
Abstract
Modelling wear of drill bits can increase the efficiency in the drilling operations. Related to the subject, it is aimed to investigate the wear mechanism of drill bits. Wear in drill bits is influenced by many factors related to the drilling and rock properties. The type and intensity of wear are dependent ...
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Modelling wear of drill bits can increase the efficiency in the drilling operations. Related to the subject, it is aimed to investigate the wear mechanism of drill bits. Wear in drill bits is influenced by many factors related to the drilling and rock properties. The type and intensity of wear are dependent on several complicated factors that are required to be considered in anticipating the rate of wear in the field and laboratory conditions. The laboratory tests have been performed in order to specify the relationships between the bit wear rate and the physico-mechanical properties, drillability, abrasive properties, and brittleness of rocks. Statistical analysis has been used to obtain equations for estimating the bit wear rate based on the rock properties. In this work, an ensemble technique is used to estimate the confidence interval and the prediction intervals for the regression models. This paper summaries the rock properties and bit wear mechanism, and argues the options to determine the bit wear rate. The test models indicate that the rock properties can give an idea of bit wear. They also show a good correlation between the bit wear rates. Also some models are developed to represent the wear quantification, and an approach is suggested in order to estimate the bit wear rate. The results obtained from studying the developed models provide a good agreement with the performance evaluation of an efficient drilling, which provide an indirect evaluation of drill bit wear rate during a drilling process, which can help to reduce the specific energy consumption and lower costs for the exchange of drill bits.
Mineral Processing
M. Diab; M. Abu El Ghar; I. Mohamed Gaafar; A. H. Mohamed El Shafey; A. Wageh Hussein; M. Mohamed Fawzy
Abstract
In this work we are concerned with the potentiality of using mineral processing for raising the grade of the valuable heavy minerals (VHMs) from the Quaternary stream sediments of Wadi and Delta Sermatai located on the southern coast of the Red Sea, Egypt. A rigorous understanding of the chemical and ...
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In this work we are concerned with the potentiality of using mineral processing for raising the grade of the valuable heavy minerals (VHMs) from the Quaternary stream sediments of Wadi and Delta Sermatai located on the southern coast of the Red Sea, Egypt. A rigorous understanding of the chemical and mineralogical characteristics of the studied samples is a prerequisite for the selection and development of the physical processing used in order to produce a high-grade concentrate. For this purpose, the grain size distribution analysis, heavy liquid separation tests as well as XRF, and SEM analysis are performed. The magnetite, ilmenite, garnet, zircon, rutile, apatite, sphene, pyrolusite, celestine, and heavy green silicates are the valuable heavy minerals recorded in the studied samples; but their quantity varies between Wadi and Delta. The upgrading experiments are performed via a shaking table in conjunction with the low and high-intensity magnetic separator in order to obtain the high-grade concentrates from the valuable heavy minerals, and after applying the optimum separation conditions, the total heavy mineral (THM) assay increase from 8.32% to 46.04% for Wadi Sermatai, while for Delta Sermatai increase from 8.37% to 50.13% into 8.89% and 9.59%, respectively, by mass yield. The THM recovery values reach 66.84% for Wadi Sermatai and 67.23% for Delta Sermatai. After the results of the chemical analysis of the concentrates, it is proved that the Sermatai area is considered as a potential source for some economic elements such as Fe, Ti, Zn, Zr, Cr, V, and Sr.
Rock Mechanics
Jagdish Lohar; Neha Shrivastava
Abstract
India is a leading producer and exporter of dimensional marble. The processing of marble into dimensional and finished forms involves sawing, grinding, and polishing, generating significant quantities of Marble Processing Waste (MPW). Efforts for bulk recycling of MPW from the rapidly expanding marble ...
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India is a leading producer and exporter of dimensional marble. The processing of marble into dimensional and finished forms involves sawing, grinding, and polishing, generating significant quantities of Marble Processing Waste (MPW). Efforts for bulk recycling of MPW from the rapidly expanding marble industry are essential due to significant environmental impacts, hindered by limited inclusion rates and complex processing requirements in current practices. Concurrently, the increased demand for geotechnical fill materials and the depletion of natural soils necessitates sustainable alternatives. Using MPW in geotechnical fills offers a viable solution, yet it lacks comprehensive characterization. The aim of this study is to evaluate MPW as a sustainable alternative to conventional geotechnical fill materials. In this study, a comprehensive analysis of MPW's physical, geotechnical, and electrochemical properties, along with its mineralogical, elemental, and chemical composition, was conducted. The findings show that MPW, being non-plastic and non-swelling with a grain size distribution and hydraulic conductivity similar to silty sands, can be used directly from disposal sites without further processing. Notably, MPW achieves a maximum dry density of 1.84 g/cm³ and exhibits internal friction angles of 36.5°, ensuring stability. Electrochemical analysis indicates low leachability risks, with pH levels of 8.1 and electrical resistivity of 6,200 ohm-cm. Scanning Electron Microscopy images reveal that MPW particles are irregular, with considerable angularity and surface roughness. These results position MPW as a viable and environmentally friendly alternative to conventional fill materials, with the potential to significantly reduce the exploitation of natural resources and advance sustainable waste management practices.
F. Habashi
Abstract
Processing of minerals and production of metals has increased greatly in recent years. As a result, the quantities of waste material and pollutants have also increased. In many cases technology has changed to cope with the problem. Processes have been either modified to decrease emissions, or replaced ...
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Processing of minerals and production of metals has increased greatly in recent years. As a result, the quantities of waste material and pollutants have also increased. In many cases technology has changed to cope with the problem. Processes have been either modified to decrease emissions, or replaced by others that are less polluting even if at a higher cost. This paper briefly reviews examples in the ferrous and nonferrous industries.
Exploitation
S. Barak; A. Bahroudi; G. Jozanikohan
Abstract
The purpose of mineral exploration is to find ore deposits. The main aim of this work is to use the fuzzy inference system to integrate the exploration layers including the geological, remote sensing, geochemical, and magnetic data. The studied area was the porphyry copper deposit of the Kahang area ...
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The purpose of mineral exploration is to find ore deposits. The main aim of this work is to use the fuzzy inference system to integrate the exploration layers including the geological, remote sensing, geochemical, and magnetic data. The studied area was the porphyry copper deposit of the Kahang area in the preliminary stage of exploration. Overlaying of rock units and tectonic layers were used to prepare the geological layer. ASTER images were used for the purpose of recognition of the alterations. The processes used for preparation of the alteration layer were the image-based methods including RGB, band ratio, and principal component analysis as well as the spectrum-based methods including spectral angel mapper and spectral feature fitting. In order to prepare the geochemical layer, the multivariate statistical methods such as the Pearson correlation matrix and cluster analysis were applied on the data, which showed that both copper and molybdenum were the most effective elements of mineralization. Application of the concentration-number multi-fractal modeling was used for geochemical anomaly separation, and finally, the geochemical layer was obtained by the overlaying of two prepared layers of copper and molybdenum. In order to prepare the magnetics layer, the analytical signal map of the magnetometry data was selected. Finally, the FIS integration was applied on the layers. Ultimately, the mineral potential map was obtained and compared with the 33 drilled boreholes in the studied area. The accuracy of the model was validated upon achieving the 70.6% agreement percentage between the model results and true data from the boreholes, and consequently, the appropriate areas were suggested for the subsequent drilling.
Mine Economic and Management
K. Shah; S. Ur Rehman
Abstract
Truck and shovel are the most common raw material transportation system used in the cement quarry operations. One of the major challenges associated with the cement quarry operations is the efficient allocation of truck and shovel to the mining faces. In order to minimize the truck and shovel operating ...
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Truck and shovel are the most common raw material transportation system used in the cement quarry operations. One of the major challenges associated with the cement quarry operations is the efficient allocation of truck and shovel to the mining faces. In order to minimize the truck and shovel operating cost, subject to quantity and quality constraints, the mixed integer linear programing (MILP) model for truck and shovel allocation to mining faces for cement quarry is presented. This model is implemented using the optimization IDE tool GUSEK (GLPK under SciTE Extended Kit) and the GLPK (GNU Linear Programming Kit) standalone solver. The MILP model is applied to an existing cement quarry operation, the Kohat cement quarry located at Kohat (Pakistan) as a case study. The analysis of the results of the relating case study reveals that significant gains are achievable through employing the MILP model. The results obtained not only show a significant cost reduction but also help in achieving a better coordination among the quarry and quality department.
Myong Nam Sin; Un Chol Han; Hyon Hyok Ri; Sung Il Jon
Abstract
Anthracite coal seam of Democratic People’s Republic of Korea was broken into particles to be soft due to geological tectonic actions through several stages in the Mesozoic era. Because the folds and faults have excessively developed and the shape of coal seam is very complicated, it is impossible ...
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Anthracite coal seam of Democratic People’s Republic of Korea was broken into particles to be soft due to geological tectonic actions through several stages in the Mesozoic era. Because the folds and faults have excessively developed and the shape of coal seam is very complicated, it is impossible to extract the anthracite coal by longwall mining system, and coal has been mainly mined by entry caving mining system. The aim of this work is to assess effectiveness of new combination of flying squirrel search algorithm (SSA) and artificial neural-network (ANN) for back-analysis of time-depending mechanical parameters of anthracite coal based on timber loads and displacements measured in the coal face entry. The case study deals with a coal face entry in Sinchang Coal Mine located in the Unsan County, South Pyongan Province, DPR Korea. To verify the good performance of new combination of the SSA and ANN, the comparison studies between proposed back-analysis method and other methods with the same purpose, are conducted using data measured in coal face entry. The mean absolute error (MAE) of weighted error norm of ANN-SSA is relatively smaller in comparison with other methods, which is 2.49. The new back-analysis is the good method to determine the suitable time-dependent mechanical parameters of anthracite coal surrounding the entry in very soft coal seam.
R. Mikaeil; Y. Ozcelik; M. Ataei; S. Shaffiee Haghshenas
Abstract
Evaluation and prediction of performance of diamond wire saw is one of the most important factors involved in planning the dimension stone quarries. The wear rate of diamond wire saw can be investigated as a major criterion to evaluate its performance. The wear rate of diamond wire saw depends upon non-controlled ...
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Evaluation and prediction of performance of diamond wire saw is one of the most important factors involved in planning the dimension stone quarries. The wear rate of diamond wire saw can be investigated as a major criterion to evaluate its performance. The wear rate of diamond wire saw depends upon non-controlled parameters related to rock characteristics and controlled parameters related to characteristics of the cutting machine and operational parameters. Under the same working conditions, the wear rate of diamond wire saw is strongly affected by the rock properties. This is a key factor that required in evaluating the wear rate of diamond wire saw. In this work, the four major dimension stone properties uniaxial compressive strength, Schimazek F-abrasivity factor, Shore hardness, and Young's modulus were selected as the criteria to evaluate the wear rate of diamond wire saw using the harmony search algorithm (HSA). HSA was used to cluster the fifteen different andesite quarries located in Turkey. The studied dimension stones were classified into three classes. The results obtained show that the algorithm applied can be used to classify the performance of diamond wire saw according to its wear rate by only some famous physical and mechanical properties of dimension stone.
Reza Ghaedrahmati; F Doulati Ardejani
Abstract
This paper utilises the modified Folchi method to assess the environmental impact of coal washing plant, Alborz Sharghi, North-east Iran. In this study, the number of factors designed in the method was slightly modified by focusing on the environmental impact of coal washing operations. In addition, ...
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This paper utilises the modified Folchi method to assess the environmental impact of coal washing plant, Alborz Sharghi, North-east Iran. In this study, the number of factors designed in the method was slightly modified by focusing on the environmental impact of coal washing operations. In addition, few other factors were designed and added to the previous factors. Then, twenty-one values of environmentally impacting factors from the study area and a case with standard amounts of effects were calculated. This method was conducted by forming an assessment matrix in which one dimension is the environmental components and the other one is impacting factors to estimate the environmental problems arising from the impacting factors of both cases. Comparison of the results of two cases shows that the amount of contamination produced by the plant, especially for components including air quality, agriculture and area landscape is significant.
Hossein Shahi; Abulghasem Kamkar Rouhani
Abstract
The method of weights of evidence is one of the most important data driven methods for mineral potential mapping in GIS. In this method, considering the characteristics of known mineralized locations, we can prospect new mineralized areas. In this research work, the method of weights of evidence has ...
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The method of weights of evidence is one of the most important data driven methods for mineral potential mapping in GIS. In this method, considering the characteristics of known mineralized locations, we can prospect new mineralized areas. In this research work, the method of weights of evidence has been used for hydrothermal gold potential mapping in Torbat-e-Heydarieh area, east of Iran. As a relatively large number of gold mineral occurrences (i.e., exactly 27 known gold mineralized locations) have been recognized in the study area, the use of the weights of evidence method for prospecting new gold mineralized zones in the area may be quite efficient. In this study, a combination of the results of the airborne geophysical, geological, argillic, propillitic and iron oxide alteration, geochemical and structural data based on the method of weights of evidence, has been made to determine probable gold mineralization zones in the form of a posteriori map of the survey area. Consequently, four major zones in this area have been identified as high gold mineralization potential zones, in which many vein and veinlet mineralization forms can be found.
Reza Ghavami-Riabi; H.F.J Theart
Abstract
The trace element contents on the surface originated from mineralization would depend to the thickness of the calcrete layer above the ore deposit on the surface. A very thick layer of calcrete may not allow for much dispersion of the elements of interest in the surface. These elements may be concentrated ...
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The trace element contents on the surface originated from mineralization would depend to the thickness of the calcrete layer above the ore deposit on the surface. A very thick layer of calcrete may not allow for much dispersion of the elements of interest in the surface. These elements may be concentrated in non-magnetic and magnetic part of calcrete. Based on the current research, mineralogical composition of the non-magnetic part of the calcrete consists of calcite, quartz and microcline and the magnetic part comprises of magnetite, hematite, calcite and albite (at Kantienpan). It could be demonstrated that calcrete samples close to the ore zone have higher contents of Cu, Zn and CaCO3 when compared to the calcrete samples further away from the ore zone. Lithogeochemical exploration program based on the visually cleaned calcrete samples may lead to the successful identification of underlying mineralization, but the dispersion of the interest elements may be severely restricted. It is however evident that these elements are available at the calcrete-sand interface and could then be dispersed by ground and rain water as in the case of mobile metal ions.
A. Entezari Harsini; S. A. Mazaheri; S. Saadat; J. F. Santos
Abstract
This paper presents the new geochemical isotopes Sr and Nd, and the mineralization data for the south Neyshabour volcanic rocks located in NE Iran. Based on the chemical classifications, the studied rocks are basaltic trachy andesite, trachy andesite, trachyte, and trachy dacite in composition. All the ...
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This paper presents the new geochemical isotopes Sr and Nd, and the mineralization data for the south Neyshabour volcanic rocks located in NE Iran. Based on the chemical classifications, the studied rocks are basaltic trachy andesite, trachy andesite, trachyte, and trachy dacite in composition. All the analyzed volcanic rocks display enrichment in light rare earth elements (LREE) relative to the heavy rare earth elements (HREE), have significant negative Ti and Nb anomalies, and have a positive U anomaly. The tectonic discrimination diagrams for the volcanic rocks in the studied area show a post-collisional arc environment. These characteristics are the specifications of the subduction-related volcanic rocks generated in a post-collisional setting. The initial 87Sr/86Sr ratios ranging from 0.70408 to 0.70593and the εNdi values between +3.34 and +5 for the four samples analyzed indicate that the studied rocks are derived from a lithospheric mantle source. Finally, it is concluded that these volcanic rocks should have formed in a post-collisional environment that followed the Neo-Tethys subduction. There are strong evidence for copper mineralization in these volcanic rocks. The main copper oxide minerals are malachite and atacamite. The copper sulfide minerals such as chalcocite, minor bornite, and covellit are also present. Chalcocite is the most abundant sulfide ore mineral present in this area. This mineralization is observed as open space filling and thin veinlets, and it is partially controlled by linear structures and fault zones. Based on the identified characteristics, this ore deposit is hydrothermal. Carbonate alteration is frequently seen in the area but argillic alteration is very low, and this issue displays a hydrothermal solution with an alkaline pH.
S. Safari Sinegani; A. Abedi; H. Asghari; A. A. Safari Sinegani
Abstract
Phytoremediation is a technology that uses plants for the remediation of the contaminated soils, sediments, tailings, and groundwaters. In this work, the ability of TrifoliumAlexanderium for the phytoremediation of the tailings soil in the Anjir-Tange coal washing plant was investigated. For this purpose, ...
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Phytoremediation is a technology that uses plants for the remediation of the contaminated soils, sediments, tailings, and groundwaters. In this work, the ability of TrifoliumAlexanderium for the phytoremediation of the tailings soil in the Anjir-Tange coal washing plant was investigated. For this purpose, Trifolium sp. was cultivated in three soils consisting of the tailings dam, an agricultural soil, and a mixed soil. The concentrations of Fe, Cr, Cd, and P, and the factorsTF (translocation factor), BCF (bio-concentration factor), and BAF (bio-accumulation factor) were measured in the soils and plants after the harvest of Trifolium sp. The results obtained showed that BCFs in the agricultural soil, tailings dam, and mixed soil were 10.4, 12.24, and 7.23, respectively. These results also showed that TrifoliumAlexanderiumwas able to accumulate Cd in the root tissues and stabilize it, and thus it can be regarded as an appropriate species for the stabilization of the Cd ions in the contaminants and soils.The results obtained suggest that this plant can be a good candidate for use in the revegetation and phytostabilization of the Cd-contaminated lands in the region.
Mineral Processing
R. Solis-Rdoriguez; S. Bello-Teodoro; A. Moreno-Baez; J. I Galvan-Tejada; J. G Arceo-Olague; H. Luna-Garcia; O. Alonso-Gonzalez
Abstract
Precious metals are currently associated with selenium (naumannite, Ag2Se) and tellurium (calaverite, AuTe2; sylvanite, (Au,Ag)2Te4) to form species refractory to cyanidation. The aim of this preliminary work was to study the use of the solvent extraction technique to recover tellurium and selenium ions ...
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Precious metals are currently associated with selenium (naumannite, Ag2Se) and tellurium (calaverite, AuTe2; sylvanite, (Au,Ag)2Te4) to form species refractory to cyanidation. The aim of this preliminary work was to study the use of the solvent extraction technique to recover tellurium and selenium ions from a synthetic solution similar to the cyanidation effluents to recycle the free cyanide back to the process. For the extraction of the Se and Te anions, the use of quaternary amines as extractants was evaluated (tallow trimethyl ammonium chloride, Quartamin TPR; hexadecyl trimethyl ammonium chloride, Amine F; and trioctyl methyl ammonium chloride, Aliquat 336) employing nonylphenol as a modifier in the organic phase (iso-octane). The results obtained showed that the extraction was strongly affected by the pH and that it was possible to recover up to 83% of Se and 10% of Te with Quartamin TPR from two synthetic solutions containing 23 mg/L of Te and 20 mg/L of Se with a molar cyanide:metal ratio of 1:4 at pH 11, a ratio of aqueous/organic (A/O) = 1 (V/V) and an extractant concentration of 0.022 mol/L. A maximum distribution coefficient (D) of 4.97 was obtained at pH 11. The McCabe-Thiele diagram indicates that two theoretical extraction stages are necessary to obtain a good extraction of Se complexes using Quartamin TPR.
H. Dao; Th. L. Pham; N. Ph. Hung
Abstract
Blasting has become a crucial work in mining operation. However, it produces high-intensity seismic waves which cause some serious troubles such as injure people, fly-rock, cracking, breaking and reducing the lifetime of adjacent buildings. In Vietnam, there have been many conflicts between residents ...
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Blasting has become a crucial work in mining operation. However, it produces high-intensity seismic waves which cause some serious troubles such as injure people, fly-rock, cracking, breaking and reducing the lifetime of adjacent buildings. In Vietnam, there have been many conflicts between residents and government about the compensation policy for these damages. The solution is proposed, in which a similar explosion is made and an instantaneous concussion meter is used to record the magnitude of the generated shock wave. The results received from this operation will be used to determine the effects of mining blast. In fact, that is an incorrect method because just by changing the type of explosives, the order, the explosives, etc., the shock wave will be significantly reduced. Nothing is ensured that another explosion causing a shock wave amplitude will not occur in the future. To solve this problem, this paper presents an online seismic wave monitoring system operating 24/24h, to transmit the recorded signal to an independent server located around the boundary of the mine. On the basis of the mechanism of generating explosive waves and the recording mechanism of shock waves, the authors have built a program to store records according to the permissible influence of Vietnam Standard and Circular 32/2019/TT- Vietnam Board of Directors.
R. Morla; Sh. Karekal; A. Godbole
Abstract
Diesel-operated Load Haul Dumper (LHD) vehicles are commonly used in underground coal mines. Despite their value as utility vehicles, the main drawback of these vehicles is that they generate diesel particulate matter (DPM), a known carcinogenic agent. In this work, an attempt is made to model DPM flows ...
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Diesel-operated Load Haul Dumper (LHD) vehicles are commonly used in underground coal mines. Despite their value as utility vehicles, the main drawback of these vehicles is that they generate diesel particulate matter (DPM), a known carcinogenic agent. In this work, an attempt is made to model DPM flows generated by LHDs in an underground coal mine environment for different DPM flow and intake air flow directions. The field experiments are conducted and used to validate the computational fluid dynamics (CFD) models and used to map the DPM flow patterns. The results obtained show that if DPM and the intake air co-flow (flow in the same direction), DPM is confined predominantly in the middle of the roadway. To the contrary, if the DPM and intake air counter-flow (flow in the opposite directions), the DPM spread occurs throughout the entire cross-section of the roadway. In the latter case, the operator will be more susceptible to exposure to high concentrations of DPM. Overall, the DPM concentration decreases with an increase in the intake air velocities. For co-flow for intake air velocities of 2 m/s, 3 m/s, and 4 m/s, the DPM concentrations at 50 m downstream of the vehicles are 39 µg/m3, 23 µg/m3, and 19 µg/ m3, respectively. The DPM concentration is also influenced by the DPM temperature at the source. For the DPM temperatures of 30 oC, 40 oC, 50 oC, and 60 oC, the DPM concentrations at 50 m downstream of the source are 43 µg/m3, 34 µg/m3, 12 µg/m3, and 9 µg/m3, respectively.
Mineral Processing
H. Paryad; H. Khoshdast; V. Shojaei
Abstract
It is well-known that entrainment of particles into the froth is a key factor in the selectivity and performance of the flotation process, especially for fine particle recovery. Since flotation is a continuous process, in this work, the effects of operating parameters on the entrainment of ash materials ...
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It is well-known that entrainment of particles into the froth is a key factor in the selectivity and performance of the flotation process, especially for fine particle recovery. Since flotation is a continuous process, in this work, the effects of operating parameters on the entrainment of ash materials in a sample coal flotation is investigated from a time-sequence viewpoint. The effects of the pulp solid content, collector concentration, frother concentration, impeller speed, and particle size on the entrainment factor and water recovery at different flotation times are evaluated using a D-optimal response surface experimental design. The experimental work carried out shows that some parameters, especially particle size and pulp density, can yield completely different responses from those reported in the literature. The observed unusual behaviours can be attributed to the entrainment mechanisms and verified by the experimental results. It is also shown that the dominant entrainment mechanism can be varied by time. In addition, the statistical analyses of the experimental design show that the effects of some parameters change during time from the initial to the final stages of the flotation process. The results obtained indicate that the particle size and pulp density are the most important parameters influencing the entrainment rate and water recovery. The effects of the collector and frother concentrations are less on the entrainment and water recovery. In addition, the interaction between the solid percentage and particle size is the only significant mixed effect.
Kausar Sultan shah; Mohd Hazizan bin Mohd Hashim; Hafeez Ur Rehman; Kamar shah bin Ariffin
Abstract
The significance of rock failure can be found from the fact that microfracture genesis and coalescence in the rock mass results in macroscale fractures. Rock may fail due to an increase in the local stress, natural fractures, weathering inducing micro-crack genesis, coalescence, and propagation. Therefore, ...
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The significance of rock failure can be found from the fact that microfracture genesis and coalescence in the rock mass results in macroscale fractures. Rock may fail due to an increase in the local stress, natural fractures, weathering inducing micro-crack genesis, coalescence, and propagation. Therefore, a comprehensive understanding of the micro-scale failure mechanism of various weathering grade sandstones based on micro-level observation and microstructure-based simulation is essential. The microscale failure response of various weathering grade sandstones is studied under the wet and dry cycles. Each sample is tested for the micro-structure and micro-fracture characteristics using the image analysis. Furthermore, the micrographs obtained are also used to create the microstructure-based models, which are then simulated in the ANSYS software. The findings indicate that the moderately weathered sandstones indicate less weight reduction than the slightly weathered sandstone. The results obtained also demonstrate that the wet and dry cycles have little effect on the particle shape and size. However, variation in the particle shape and size implies that this is a result of the prevailing interaction of rock and water particle. The microscale simulation reveal that both UCS and BTS decrease from 37 MPa to 19 MPa and 9 MPa to 4 MPa as the density of the micro-structure increases. The results reveal that the primary fracture deviation from the loading axis increases with increasing density in the micro-structural micro-structures, although this effect reduces with further increasing density in the micro-structures.
M. Fayiah
Abstract
Sierra Leone is blessed with abundant natural resources but yet prone to environmental degradation due to the mining operations. Most often, the mining communities are faced with social tensions, as a result of the possible trade-off between the expected employment impact and the cost of mining operations ...
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Sierra Leone is blessed with abundant natural resources but yet prone to environmental degradation due to the mining operations. Most often, the mining communities are faced with social tensions, as a result of the possible trade-off between the expected employment impact and the cost of mining operations to the environment. Over the past decades, the contribution of the mining sector to the development of the country has been overshadowed by the fact that the mining operations have had adverse negative effects, mainly due to the country's weak environmental policies and the failure of the mine monitoring institutions, to supervise the operations of mining company operations. This article seeks to examine both the environmental and the social implication of mining operations on three mining edge communities in Sierra Leone. This paper also utilizes secondary data from the published articles, government’s reports, workshops and conference proceedings, policy documents of non-governmental organizations, newspapers, and the like to generate this writer's view on the topic under review. The thrust of the review will be on the following: Sierra Rutile Limited, Koidu Holdings Limited, and Shandong Iron Ore Mines. The above mining companies have been carefully selected due to the fact that they are located close to dwelling communities, and have been mining in Sierra Leone over a long period of time. The environmental performance index and the mining impact framework are used to clearly show the impact of mining operations on the environment in Sierra Leone. As a result of mining operations, deforestation is skyrocketing, public discomfort and air pollution has worsened, and social unrest has increased as a result of some unacceptable consequences including pollution of water source without recourse to short-term remedy. The literature reviewed by this writer reveals that the mining activities have two faces in Sierra Leone. One is that it serves as a resource curse. An example to this sad reality is the outbreak of civil war, social unrest among others. On the other hand, the mining sector is one of the principal backbones of the economy. It contributes to the livelihood of the country. This paper introduces three-way approaches of mining sector operation remedies that include but not limited to: 1) sound Environmental Impact Assessment (EIA) adoption before mining operations starts; 2) carrying out Strategic Environmental Assessment (SEA); 3) regular engagement with all stakeholders of mining-affected communities. This article recommends that restoration activities by mining companies go along with extraction and adequate compensation.
Devraj Dhakal; Salad Omar Abdi; Kanwarpreet Singh; Abhishek Sharma
Abstract
The highway contributes significantly to human existence by providing safe, dependable, and cost-effective services that are environmentally friendly and promote economic progress. Highway projects need extensive planning to prevent work revisions, save time and cost, and increase job efficiency. Without ...
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The highway contributes significantly to human existence by providing safe, dependable, and cost-effective services that are environmentally friendly and promote economic progress. Highway projects need extensive planning to prevent work revisions, save time and cost, and increase job efficiency. Without a doubt, Highway transportation system must be constantly updated to keep up with technology breakthroughs, environmental change, and rising client needs. Incorporating Remote Sensing (RS) and Geographic Information Systems (GISs) has the potential to go beyond the limitations of RS, which typically collects information about the earth and its peripheries from space, and does not alter, analyze, calculate, query or display geographic engineering maps. Over the last few decades, the fusion of RS and GIS has shown promise, and the researchers are employing it in different stages of the Highway Planning and Development Process (HPDP) such as optimal route analysis, geometric design, operation and management, traffic modeling, accident analysis, and environmental impact analysis (noise pollutions, air pollutions). This paper gives an overall review of the use of RS and GIS on HPDP at various stages of their lifecycles.
Exploration
Naman Chandel; Sushindra Kumar Gupta; Anand Kumar Ravi
Abstract
Groundwater is an essential resource for human survival, but its quality is often degraded by the human activities such as improper disposal of waste. Leachate generated from landfill sites can contaminate groundwater, causing severe environmental and health problems. Machine learning techniques can ...
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Groundwater is an essential resource for human survival, but its quality is often degraded by the human activities such as improper disposal of waste. Leachate generated from landfill sites can contaminate groundwater, causing severe environmental and health problems. Machine learning techniques can be used to predict groundwater quality and leachate characteristics to manage this issue efficiently. This study proposes a machine learning-based model for the prediction of groundwater quality and leachate characteristics using the effective water quality index (EWQI). The leachate dataset used in this study was obtained from a landfill site, and the groundwater quality dataset was collected from literature review. The mean values of TDS, Ca, Mg, NO3-, and PO4- exceeded the prescribed limit for drinking water purposes. The proposed model utilizes a machine learning architecture based on a convolutional neural network (CNN) to extract relevant features from the input data. The extracted features are then fed into a fully connected network to estimate the EWQI of the input samples. The model, trained and tested on leachate and groundwater quality datasets, achieves a high accuracy and computational efficiency, aiding in predicting groundwater quality and leachate characteristics for waste management.
Mineral Processing
Gh. A. Parsapour; S. DarvishTafvisi; E. Arghavani; M. J. Rajabi; A. Akbari; S. Banisi
Abstract
The new copper processing plant of the Sarcheshmeh copper complex consists of two parallel circuits. After a primary crushing, the ore is sent to a SAG mill, and the product is further ground in a ball mill. The overflow of the hydrocyclones is fed to a flotation circuit that contains 8 rougher tank ...
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The new copper processing plant of the Sarcheshmeh copper complex consists of two parallel circuits. After a primary crushing, the ore is sent to a SAG mill, and the product is further ground in a ball mill. The overflow of the hydrocyclones is fed to a flotation circuit that contains 8 rougher tank cells (RCS130), 3 cleaner cells (RCS50), 5 scavenger cells (RCS50), and a flotation column (as recleaner). The circuit was initially designed to process a feed containing 0.8% Cu but due to a change in the ore type, the feed grade decreased to 0.6% Cu. This resulted in a reduction in the final concentrate grade and the recovery from 28% and 85.5% to 24% and 84.4%, respectively. Based on the original design, the copper and silica recovery in the cleaner cells should be 69% and 55%, respectively, but these values increased to 85% and 75% due to a higher retention time. The rather high silica recovery was found to be the main source of the lower final concentrate grade. In order to reduce the retention time of particles in the cleaner cell from 13.7 to 6.9 min, the rougher concentrates of two parallel circuits were fed to only one cleaner-scavenger and regrind circuit. This modification increased the cleaner and final concentrate grade from 15.1% and 24.5% to 17% and 26%, respectively. The overall outcome of the circuit modification was evaluated to be a 10% reduction in the energy consumption without any loss in the overall copper recovery.
Sh. Sadat Etemadzadeh; G. Emtiazi; Z. Etemadifar
Abstract
Most studies on sulfur bioleaching from coal depend on an autotrophic microorganism with a low growth and a long leaching time. For this reason, heterotrophic heat and acidic pH-resistant Alicyclobacillus was used as the growing and resting cells for the sulfur and iron removal from coal. The results ...
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Most studies on sulfur bioleaching from coal depend on an autotrophic microorganism with a low growth and a long leaching time. For this reason, heterotrophic heat and acidic pH-resistant Alicyclobacillus was used as the growing and resting cells for the sulfur and iron removal from coal. The results obtained were analyzed by XRF. The data showed that 26.71% of sulfur was removed by Alicyclobacillus in a few days; however, 49.07% of sulfur was removed by Acidithiobacillus in 30 days. This was interesting since the leachings of zinc, strontium, titanium, and iron by Alicyclobacillus, obtained in a few days, were almost the same as the leachings by Acidithiobacillus in 30 days. The results obtained also showed that the Alicyclobacillus cells growing at 55 ˚C removed most of the coal impurities without any change in the carbon content of this fuel. To the best of our knowledge, coal leaching by Alicyclobacillus is reported for the first time.
