J. Manyepa; V. Patson Mutambo
Abstract
Designing suitable extraction methods for mining randomly occurring pocket formation of gemstones has never been easy at the Musakashi emerald mine due to the limited geological information. In order to improve the productivity as well as the recovery, in this work, we undertake a detailed ...
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Designing suitable extraction methods for mining randomly occurring pocket formation of gemstones has never been easy at the Musakashi emerald mine due to the limited geological information. In order to improve the productivity as well as the recovery, in this work, we undertake a detailed geological survey (airborne, surface mapping, geochemical sampling, and trenching activities), and review, analyze, and establish the appropriate extraction methods, and conduct the economic viability of the mining emeralds in the Musakashi area. A total of 51 holes are drilled in order to define the mineralization and estimate the mineral resource for the rubble ore and the in-situ ore zones using the Surpac Geovia software. The diamond drilling unravels the existence of an alteration zone enveloping the shales in an area of 150m by 100m. The emerald is localized within these reaction zones, and is estimated to extend to a depth of about 20–30m below the surface. The total mineral resource stands at 345, 290 grams for the rubble ore and 123,870 grams for the discordant veins. From the geological information obtained, a trial pit design is established with a target of increasing recovery of emeralds from the current 10 kg to 100 kg per year.
B. Olamide Taiwo
Abstract
Assessment of blast results is a significant approach for the improvement of mining operations. The different procedures for investigating rock fragmentation have their limitations, causing different variation prediction errors. Thus every technique is site-explicit, and applicable for a few explicit ...
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Assessment of blast results is a significant approach for the improvement of mining operations. The different procedures for investigating rock fragmentation have their limitations, causing different variation prediction errors. Thus every technique is site-explicit, and applicable for a few explicit purposes. This work evaluates the existing empirical blast fragmentation model predictions in the case study of small-scale dolomite quarries. An attempt is made to compare the prediction accuracy of the modified Kuz-Ram model, Lawal 2021 model, and Kuznetsov-Cunningham-Ouchterlony (KCO) model with the WipFrag© analysis result and proposed artificial neural network (ANN) models. The prediction error analysis of the current models and that of the new proposed ANN models is evaluated using the three model assessment indices. The assessment indices uncover that the KCO model when compared to the modified Kuz-Ram model has the least error for most blast round percentage passing size predicted. However, the proposed artificial neural network models show high prediction exactness in predicting blast fragment mean size than the existing empirical models. Therefore, the proposed ANN models can be used to improve the productivity of small-scale dolomite blasting operation results for practical purposes.
S. Mulenga; R. Kaunda
Abstract
In this work, a new drilling and blasting design methodology is introduced and applied at a case study mine to improve productivity. For the case study copper mine, a blast diameter of 203 mm is proposed to be used in the ore zone to meet the new required production rate of 90mtpa from 75mtpa. Currently, ...
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In this work, a new drilling and blasting design methodology is introduced and applied at a case study mine to improve productivity. For the case study copper mine, a blast diameter of 203 mm is proposed to be used in the ore zone to meet the new required production rate of 90mtpa from 75mtpa. Currently, the Konya and Walter’s model is used to generate drilling and blasting design at a blasthole diameter of 172 mm. The new drilling and blast design approach is advantageous in the sense that it generates a lower specific drilling value and predicts an average fragment size compared with the current method being used. In this regard, a modified available energy blast design method that incorporates the blastability index of ore zone in the calculation of the input powder factor is introduced. The results of the blast design simulations at a 203 mm blasthole diameter shows that the modified available energy model generates a drilling and blasting design with a specific drilling value that is 15.3% less than that generated by the Ash’s and Konya and Walter’s models. Further, the modified available energy model generates a blast design with a predicted average fragment size that is 3.4% smaller than that generated by the Ash’s model, and 6.7% smaller than that generated by the Konya and Walter’s model.
Mineral Processing
G.G. Berhe; A. Velázquez del Rosario; Y. Abubeker; W. Girma; T. Bogale; C. Mulugeta Sisay
Abstract
The decomposition of the Ethiopian Kenticha tantalite ore was studied using the KOH fusion and H2O leaching system at 400 0C for a 1 h reaction time. The experimental results obtained showed that 27 wt% of Ta2O5 was mainly transformed into insoluble KTaO3, not to be KNbO3, and as well, into the dissolved ...
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The decomposition of the Ethiopian Kenticha tantalite ore was studied using the KOH fusion and H2O leaching system at 400 0C for a 1 h reaction time. The experimental results obtained showed that 27 wt% of Ta2O5 was mainly transformed into insoluble KTaO3, not to be KNbO3, and as well, into the dissolved liquor containing 94.73 vol% of Nb2O5 and 75.80 vol% of Ta2O5. The observations, supported by the EDXRF, XRD, and ICP-OES techniques, showed that the ratio of the dissolved mixture of Nb and Ta metal ions was beneficial to the solvent extraction from both Ta2O5 and Nb2O5. Niobium and tantalum were extracted from their neutralized alkaline dissolved and hydrolyzed solution by a new process using the EMIC/AlCl3 ionic liquid as the extractant using selective stripping, precipitation, and calcination of a highly crystalline pure 99.84 wt% of Nb2O5 and amophours 90.81 wt% of Ta2O5. The compositions of the dissolved metal ions and solids were analyzed by the ICP-OES, EDXRF, XRD, and FT-IR techniques.
Exploration
V. Adjiski; D. Mirakovski; Z. Despodov; S. Mijalkovski
Abstract
Auxiliary ventilation of the blind development heading in underground mines is one of the most challenging work activities amongst mining underground operations. The auxiliary forcing ventilation system provides positive pressure, cooling, controlling gas layering, and removing diesel fumes and dust ...
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Auxiliary ventilation of the blind development heading in underground mines is one of the most challenging work activities amongst mining underground operations. The auxiliary forcing ventilation system provides positive pressure, cooling, controlling gas layering, and removing diesel fumes and dust levels from development headings, stopes, and services facilities. The effectiveness of the auxiliary forcing ventilation system depends upon many system variables. Currently, no scientific models and calculations are available that can be used to estimate the optimal distance from the outlet of the auxiliary forcing ventilation system to the development heading in underground mines that can provide the most efficient ventilation close to the face of the heading. In this work, scenarios are developed and simulated with a validated CFD model inside the ANSYS Fluent software. In each scenario, the system parameters such as dead zone, mean age of air, and face velocity are calculated, which are later used in the optimization process. By examining these parameters at the development heading zone, we can quantify the effectiveness of the ventilation system and confirm that the system design meets the government regulations. This work is carried out using the k-epsilon realizable turbulent model inside the ANSYS Fluent software.
R. Koner
Abstract
The Wardha valley coalfields, situated in the western part of India, contribute to more than 7% of the national coal production. The open-pit mining methods are the modes of exploitation of coal in the majority of the mines in the area. Due to the increased depth of working and higher stripping ...
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The Wardha valley coalfields, situated in the western part of India, contribute to more than 7% of the national coal production. The open-pit mining methods are the modes of exploitation of coal in the majority of the mines in the area. Due to the increased depth of working and higher stripping ratio, the output of waste overburden is increased. The challenges are the scarcity of the available land for dumping waste overburden geo-material safely. Optimization of the mine dump slope geometry is the only available alternative in the hands of the management in order to increase the life of the projects and continue the production of coal. This investigation specifically addresses this issue, and proposes a combination of the optimum geometric configurations of the dump slope. This work utilizes the computational power of the numerical modeling technique in order to solve a large number of alternatives and zero them down to the optimum combination. The numerical modeling is considered as a major external factor that contributes to the mine dump's instability. This work shows an 18% increase in the dumping waste material volume in the present condition. This investigation also reveals that double stage dumping is comparably better in optimizing the dump slope configuration.
Muhammad Junaid; Rini Asnida Abdullah; Radzuan Sa'ari; Wahid Ali; Amber Islam; Mahmut Sari
Abstract
This research work aims to critically analyze the efficacy of inexpensive and rapid 2D electrical resistivity tomography (2D ERT) survey for sub-surface geological delineation of granite deposits. The research work involves six ERT profiles using the Schlumberger protocol with an inner and outer electrode ...
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This research work aims to critically analyze the efficacy of inexpensive and rapid 2D electrical resistivity tomography (2D ERT) survey for sub-surface geological delineation of granite deposits. The research work involves six ERT profiles using the Schlumberger protocol with an inner and outer electrode spacing of 5 m and 10 m, respectively. In addition, the unmanned aerial vehicle (UAV) survey is also performed to obtain the terrain information of the studied area. At the same time, a few boreholes are drilled to validate the 2D ERT interpretations. The 2D ERT survey reveals that strong resistivity contrast enables inverted resistivity imaging to characterize the deposit such as topsoil (100-800 Ωm), fracture granite (800-2300 Ωm), and solid granite (> 2300 Ωm). The results obtained from UAV, 2DERT, and borehole survey are further processed to estimate the bedrock to topsoil ratio to assess the feasibility of the deposit. The bedrock to topsoil ratio, estimated by 2D ERT and borehole, is 3.2 and 2.2, respectively. At the same time, the combined UAV, 2D ERT, and borehole survey calculates the bedrock volume 3.2 times to topsoil. Thus the research work allows us to conclude that 2D ERT is an inexpensive, viable, and efficient technique for sub-surface geological documentation, and helps select appropriate mining methods.
A. Owolabi
Abstract
In this paper, we report a geospatial assessment of the selected mine sites in the Plateau State, Nigeria. The aim of this work is to determine the impact of mining on the terrain as well as the Land Use/Land Cover (LULC) of the host communities. The Shuttle Radar Topographic Mission (SRTM) is used for ...
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In this paper, we report a geospatial assessment of the selected mine sites in the Plateau State, Nigeria. The aim of this work is to determine the impact of mining on the terrain as well as the Land Use/Land Cover (LULC) of the host communities. The Shuttle Radar Topographic Mission (SRTM) is used for the terrain mapping. The derived impact of mining on LULC between 1975 and 2014 is determined by classifying the relevant Landsat imageries. The digital terrain map reveal that the mining activity is not well-coordinated. Hence, the parts of the mine sites that are rich in the desired minerals are punctuated with low depth, while the other parts have high terrain as a result of the haphazard mining activity. The analysis of the LULC change show that the degraded land (DL), built-up area (BU), water bodies (WB), and exposed rock outcrop (RO) increase by 15.68%, 4.68%, 0.06%, and 14.5%, respectively, whereas the arable farmland (FL) and forest reserve (FR) decrease by 28.29% and 6.63%, respectively. Mining has adversely affected the natural ecology of the studied area. Therefore, the mine sites should be monitored, and their environmental damages should be pre-determined and mitigated. There should be regular inspections to keep these activities under control. The existing laws and regulations to conserve the natural ecosystems of the host communities should be enforced to curtail the excesses of the operators of the mining industries. Restoration of the minefields to reduce the existing hazards prevent further environmental degradation, and facilitating the socio-economic development of the area is also suggested.
N. I. Aziz; I. Porter; F. Sereshki
Abstract
The volumetric changes in the coal matrix (Coal Shrinkage), permeability under various gas environment conditions as well as perographical properties were studied in the laboratory. The shrinkage and permeability of coal were examined with respect to changing gas type and confining pressures. The shrinkage ...
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The volumetric changes in the coal matrix (Coal Shrinkage), permeability under various gas environment conditions as well as perographical properties were studied in the laboratory. The shrinkage and permeability of coal were examined with respect to changing gas type and confining pressures. The shrinkage tests were carried out in high-pressure bombs while the permeability study was conducted in a specially constructed high-pressure chamber. Methane (CH4), carbon dioxide (CO2), nitrogen, (N2) and a 50% -50% volume mixture of CO2/CH4 gas were used in the study. The tests showed that under different pressure levels gas type affected permeability and shrinkage characteristics of coal. This paper presents a case study of Tahmoor Colliery, NSW, Australia and an overall discussion on coal shrinkage, permeability and coal petrography data of Tahmoor that permits a better understanding of the gas regime in this mine. The results are important to the further understanding of the inter-relationship between gas flow, the coal matrix and permeability in ‘normal’ and ‘tight’ coal conditions (locally referred to as disturbed coal).
S. R. Torabi; M. Ataei; M. Javanshir
Abstract
A literature review revealed that most of the empirical equations introduced for determination of the uniaxial
compressive strength (UCS) of rocks based on the Schmidt hammer rebound number (N) are not sufficiently
reliable mostly due to the relatively low coefficient of correlations. This is ...
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A literature review revealed that most of the empirical equations introduced for determination of the uniaxial
compressive strength (UCS) of rocks based on the Schmidt hammer rebound number (N) are not sufficiently
reliable mostly due to the relatively low coefficient of correlations. This is attributed to the fact that in most
cases one formula is used for all types of rocks, although the density of rocks is introduced to the formulae in
some cases. On the other hand, if one specific relationship between N and UCS is introduced for one rock
type, the equation will yield a much higher coefficient of correlation. During a research program supported
by the Shahrood University of Technology, Iran, a third type of approach was considered. The study aimed
to establish a relationship between N and UCS of a rock mass under particular geological circumstances. As
an example, in this study, the immediate roof rock of coal seams in North-Eastern coal fields of Iran was
selected. In order to determine the N and UCS, a significant number of samples were selected and tested,
both in-situ and in the laboratory, and a new equation was established. The equation can be used to predict
UCS of the roof rock in coal extracting areas in this zone by performing simple in-situ Schmidt hammer
tests. It is predicted that such a procedure will be feasible for other geological conditions.
M. Behnia; K. Goshtasbi; M. Fatehi Marji; A. Golshani
Abstract
Numerical methods such as boundary element and finite element methods are widely used for the stress analysis in solid mechanics. This study presents boundary element method based on the displacement discontinuity formulation to solve general problems of interaction between hydraulic fracturing and discontinuities. ...
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Numerical methods such as boundary element and finite element methods are widely used for the stress analysis in solid mechanics. This study presents boundary element method based on the displacement discontinuity formulation to solve general problems of interaction between hydraulic fracturing and discontinuities. The crack tip element and a higher order boundary displacement collocation technique are used to study the hydraulic fracture propagation and its interaction with the pre-existing cracks and discontinuities in an elastic rock mass. The maximum tangential stress criterion (or -criterion) and the strain energy density criterion (SED) are used to obtain the fracture path and the results of both criteria are compared with each other. The comparison of numerical method with the results brought in the literature shows a good performance of the method in the case of interacting cracks.
Blessing Olamide Taiwo; Gebretsadik Angesom; Yewuhalashet Fissha; Yemane Kide; Enming Li; Kiross Haile; Oluwaseun Augustine Oni
Abstract
Rock blast production rate (BPR) is one of the most crucial factors in the evaluation of mine project's performance. In order to improve the production of a limestone mine, the blast design parameters and image analysis results are used in this work to evaluate the BPR. Additionally, the effect of rock ...
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Rock blast production rate (BPR) is one of the most crucial factors in the evaluation of mine project's performance. In order to improve the production of a limestone mine, the blast design parameters and image analysis results are used in this work to evaluate the BPR. Additionally, the effect of rock strength on BPR is determined using the blast result collected. In order to model BPR prediction using artificial neural networks (ANNs) and multivariate prediction techniques, a total of 219 datasets with 8 blasting influential parameters from limestone mine blasting in India are collected. To obtain a high-accuracy model, a new training process called the permutation important-based Bayesian (PI-BANN) training approach is proposed in this work. The developed models are validated with new 20 blast rounds, and evaluated with two model performance indices. The validation result shows that the two model results agree well with the BPR practical records. Additionally, compared to the MVR model, the proposed PI-BANN model in this work provides a more accurate result. Based on the controllable parameters, the two models can be used to predict BPR in a variety of rock excavation techniques. The study result reveals that rock strength variation affects both the blast outcome (BPR) and the quantity of explosives used in each blast round.
Kh. Maroufi Naghadehi; A. Hezarkhani; K. Seifpanahi Shabani
Abstract
Taknar deposit is located about 28 km to the north-west of Bardaskan in the Khorasan-e-Razavi province, which is situated in the north-eastern part of Iran. This deposit is unique, formed within the Taknar formation in the Ordovician time. As a result, it is of much interest to many researchers working ...
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Taknar deposit is located about 28 km to the north-west of Bardaskan in the Khorasan-e-Razavi province, which is situated in the north-eastern part of Iran. This deposit is unique, formed within the Taknar formation in the Ordovician time. As a result, it is of much interest to many researchers working in this field. By choosing the lithogeochemical study performed to recognize new exploration targets which a new stage in the field. After pre-processing the lithogeochemical data obtained, the distribution maps were obtained for the element anomalies and alteration indices. The ratios of additive composite haloes were used to study the erosion levels in the Taknar area. In order to produce the favorability map, eight information layers were integrated using the simple overlay method, and four new exploration targets were obtained.
J. Mantey; F. Owusu-Nimo; K.B. Nyarko; A. Aubynn
Abstract
The uncontrolled spread of illegal artisanal small-scale gold mining (ASM), popularly termed “galamsey” in Ghana, has, for decades, impacted adversely upon water bodies, soils, wildlife, human health, and safety. A lack of understanding, however, of the types of galamsey, their operational ...
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The uncontrolled spread of illegal artisanal small-scale gold mining (ASM), popularly termed “galamsey” in Ghana, has, for decades, impacted adversely upon water bodies, soils, wildlife, human health, and safety. A lack of understanding, however, of the types of galamsey, their operational attributes, and their relative impacts has unfortunately hindered an effective policy response despite numerous calls from civic societal groups to address this menace. This paper is part of a comprehensive study in 11 selected municipal and district assemblies of the Western Region of Ghana to help provide an in-depth understanding into the galamsey operations in Ghana. It discusses the various forms of galamsey, their operational attributes, and relative environmental impacts. Through extensive literature review, site visits, and task observations, five broad categories and 11 sub-groupings of galamsey were unearthed based on the gold deposit type, resources used, origin of technology used, mining, and processing style as well as the local names given. These include (1) Placer/alluvial galamsey (“dig and wash”, “washing plant”, “washing board”, “anwona”, dredging, and panning), (2) Underground galamsey (abandoned underground shafts and “sample pit”), (3) Surface (“chamfi”) galamsey, (4) Mill-House galamsey, and (5) Selection galamsey. Whilst the underground and selection galamsey involve ore mining only, the mill-house focuses exclusively on ore processing. The alluvial and surface galamsey, however, involve simultaneous mining and ore processing activities. The information presented in this paper could prove valuable to policy formulation efforts, design, and implementation of effective wasteland remediation programs by governments, conservation organizations, and other stakeholders in hard-hit regions with similar illegal gold mining dilemma.
Maysam Abedi; Kiomars Mosazadeh; Hamid Dehghani; Ahmad MadanchiZare
Abstract
This paper describes an efficient edge-preserved regularization algorithm for downward continuation of magnetic data in detection of unexploded ordnance (UXO). The magnetic anomalies arising from multi-source UXO can overlap at a height over the ground surface, while causative sources may not be readily ...
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This paper describes an efficient edge-preserved regularization algorithm for downward continuation of magnetic data in detection of unexploded ordnance (UXO). The magnetic anomalies arising from multi-source UXO can overlap at a height over the ground surface, while causative sources may not be readily separated due to low level of signal-to-noise ratio of the observed data. To effectively the magnetic method work in the cleanup stage of contaminated area with UXO, the magnetic anomalies of UXO sources should be enhanced in order to separate the locations of different sources. The stable downward continuation of magnetic data can increase the signal-to-noise ratio which subsequently causes the separation of UXO sources by enhancing the signals. We formulate the downward continuation as a linear ill-posed deconvolution problem in this study. To obtain a reasonable downward continued field, it is stabilized in a Fourier domain to regularize the downward solution using the edge-preserved (or total-variation) algorithm. The L-curve method is used to choose the optimum value of the regularization parameter which is a trade-off between the misfit and the solution norms in the cost function of optimization problem. A synthetic magnetic field is constructed from isolated multi-source UXO anomalies, whose results show that the data can be stably downward continued by the proposed method. Likewise, a field data set has been provided to demonstrate the capability of the applied method in UXO detection.
H. Mohammadi; M. A. Ebrahimi Farsangi; H. Jalalifar; A. R. Ahmadi; A. Javaheri
Abstract
In advance longwall mining, the safety of mine network, production rate, and consequently, economic conditions of a mine are dependent on the stability conditions of gate roadways. The gate roadway stability is a function of two important factors: 1) characteristics of the excavation damaged zone (EDZ) ...
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In advance longwall mining, the safety of mine network, production rate, and consequently, economic conditions of a mine are dependent on the stability conditions of gate roadways. The gate roadway stability is a function of two important factors: 1) characteristics of the excavation damaged zone (EDZ) above the gate roadway and 2) loading effect due to the caving zone (CZ) above the longwall working, which can extend the EDZ size. Generally, due to the coal seam dip, the failure possibility of main gate roadway is more severe than tail gate roadway. The aim of this work is to determine the longwall working effect on the EDZ extension above main gate roadway. To achieve this purpose, considering three factors involved in the CZ characteristics, the coal seam properties (dip and thickness) and the geomechanical properties of hangingwall, a new geometrical model is developed. Then, based on the geometrical calculations, a new relationship is presented to determine the working influence coeffiecint. Furthermore, taking into account the new geometrical model, an algorithm is suggested for the stability analysis of main gate roadways. Validation of the new geometrical model is carried out by the instrumentation and monitoring results of a longwall working carried out in the Parvade-2 coal mine of Tabas, Tabas, Iran. The results obtained show that there is a good agreement between the values obtained by the new model and the actual measured values. Finally, a sensitivity analysis is carried out on the effects of pillar width, bearing capacity of support system, and coal seam dip.
Ahmed Abd El-Dayiem Abd El-Fatah; Ahmed Ali Madani; Adel Abd Allah Surour; Mokles Kamal Azer
Abstract
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 ...
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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.
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.
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.
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.
