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By B. Dubreuil

Arsenical bearing deposits are posing an increasing challenge for the mining industry. In particular, mineral processing of arsenical sulfidic ores for base and precious metals recovery tend to produce problematic arsenical tailings. This arsenic being present as sulphide or oxide, tends to dissolve, contaminating surface and underground waters. To meet the environmental regulations, it is often required to stabilize the arsenic in a more insoluble form. Nichromet has developed a new patented technology using vitrification of the arsenic oxide in an economical way, giving a stable solid, well below the environmental regulations upon leaching. This technology involves oxidation of As (III) to As (V), by using a low cost natural oxidizer and transformation of the produced arsenic oxide into calcium arsenate, which is not volatile at the melting temperature of the glass. This technology would be advantageously applied on most cases around the world where sulphide concentrates are oxidized in a fluidized bed or smelted.

Aug 1, 2013

By Shugang Li

Coal and coal-bed methane are valuable energy resources. If they can be extracted simultaneously and safely, the triple purposes of mine safety production, new energy resource supply and environmental protection can be fulfilled. After mining, the mining induced fissure distribution feature and methane delivery behavior in overlying strata were closely related to the relieved methane degasification. Using physical simulation and numerical simulation, it was explained that the distribution feature of mining induced fissure was the Elliptic Paraboloid Zone (EPZ) in three-dimensional space. Based on the key stratum theory, the types, parameters, characteristics and dynamic evolution behavior of the mining induced fissure EPZ were analyzed. Applying environmental fluid mechanics and the mass transfer theory, the relieved methane floating-diffusion equation of the EPZ was established, and the corresponding transport process was analyzed. Using the field practice of relieved methane degasification in Tianchi Coal Mine, it explained that the mining induced fissure EPZ was the storage and delivery area of relieved methane. The degasification effect will thus be useful if the drainage system is laid in the EPZ. Such studies can provide the theoretical basis and technical support for the safe simultaneous extraction of coal and methane.

Aug 1, 2013

By D. D. Liu

This paper proposes a charge induction dust measurement method based on detrended fluctuation analysis (DFA) for use in coal mine environments, based upon electrostatic interference, dust properties, wind speed, particle size, moisture content and other factors. In this methods, sequence x(t) is first obtained through a dust concentration sensing probe, and then the cumulative deviation y(t) is calculated, and y(t) is divided into same lengths. Secondly, a first-order linear fit is used for data of each interval, and mean-square deviation filtered DFA was calculated for each interval. Finally, the dust mass concentration of the corresponding time is obtain by supplemented calibration coefficient and fitted the data point which is the mean and square root for all lengths of interval. Simulation and verification experiments showed that the charge induction dust measurement method based on DFA can reduce coal mine electrostatic interference effects with high accuracy. The design has been successfully applied to select areas.

Aug 1, 2013

The goal of this presentation is to firstly, review mine effluent permits in a number of regulatory jurisdictions; and secondly, to develop a strategy for incorporating the regulatory requirements into the environmental assessment (EA) process for new mine proposals. The focus was on the province of British Columbia (BC) and their recent initiative on the One Project, One Process initiative. This task was approached by reviewing mine effluent permits for various regulatory jurisdictions and comparing them to BC mine effluent permits. This comparison revealed a variety of approaches for designing mine effluent permits, but there is a common scientific approach, which supports the conclusion that the permitting of mine site discharges can be designed based on a scientific approach. This approach is expected to: (a) achieve sound environmental protection, (b) demonstrate the application of Best Achievable Technology, (c) incorporate sound sustainability approaches, (d) incorporate regulatory objectives, and (e) create efficiencies for the regulator and mining industry. There is an essential precursor to developing a sciencebased effluent permit for which the proponent must provide: (1) the necessary technical assessment information to demonstrate the mine effluent permit application will result in an environmentally protective effluent discharge, to the satisfaction of the permitting agency; (2) the necessary level of detail for essential mitigation pollution control works to demonstrate how they will be operated to achieve the necessary treatment goals; (3) the necessary level of detail for non-treatment mitigation (passive treatment, or passive pollution control); and (4) the necessary level of detail to demonstrate how pollutants will be prevented from being mobilized (or being generated) from ore and waste materials, or, if the pollutant originates from an added milling reagent, how the reagent will be reduced. While (active) mitigation pollution control equipment is more definable in an effluent permit, non-treatment mitigation is more nebulous in terms of defining in a mine effluent permit; it is therefore recommended that appropriate management plans be developed for essential mitigation pollution control and non-treatment mitigation (passive treatment) and submitted with the proponent?s EA/effluent permit application packages. Major deficits in adequate active and passive pollution control will inevitably lead to regulatory impediments to developing a permit and allowing a mine to be developed, although EA processes strive to preclude major permit information gaps; the onus is on the proponent to provide complete information in this area. Hence the importance of EA processes ensuring that the major technical information requirements for effluent permit development are included in the EA phase. Recently, this aspect of the mine EA process has taken on a new role under the political efforts of One Project, One Review Process (Canadian) and One Project, One Process (in BC). These initiatives translate, in part, to ?synchronous permitting? (in BC): effluent permitting, for example, may be initiated shortly after the proponent submits the EA application to Ministry of Environment.

Aug 1, 2013

By Marketa D. Evans

The mining industry has a significant opportunity to capitalize on its past learnings in order to build better social relationships. The industry?s relationship with society is both critical and under pressure. Rising levels of public opposition and social conflict are already having material impacts on operations around the world. Industry has an opportunity to shape the future direction of this social engagement, build public trust and proactively respond to a material risk to operations, but first it needs to better understand the nature of the challenges and the urgency of addressing them.

Aug 1, 2013

By A. Carbonari

In order to gain competitiveness and compete at a global level, construction companies should improve their efficiency. The problem is even more relevant in the construction field, whose work processes find it hard to evolve towards new automated methods and techniques in the management field. For that reason, this paper suggests how construction companies could apply new technologies to implement automated management of environmental hazards. Based on a survey regarding the environmental risks presently experienced in construction sites, noise and dust were considered two of the main hazards. So in this paper a networked system for real time remote monitoring of the spatial distribution of dust in construction sites was developed. Such a system would relieve builders from the commitment of on-site surveys, allowing for a continuous monitoring of the site conditions and of the real exposure of each worker and pass-by to the pollutants generated by construction works. The main system requirements considered are: easy to deploy, reliable, as accurate as needed to be able to send real-time warnings and store a good estimation of the real exposure to which involved people have been subject to. So far the research produced a prototypical hardware for dust monitoring made up of wireless sensors which can be easily deployed on site. The sensors were calibrated by means of laboratory tests, where their measurements were compared with those collected by means of highly accurate instruments, which were taken as a reference. Thanks to these experiments, calibration curves for the sensors were worked out, showing also the measurement range of the sensors.

Aug 1, 2013

By H. H. Wang

Construction safety documents regulate significant safety actions and requirements by which construction workers or employees should abide in order to secure them from occupational hazard events. Therefore, facilitating faster identification of applicable safety requirements from the documents has become an important topic in the construction safety domain. To address the need in this regard, tools and techniques have been developed and research efforts have been made. One of the research efforts is to utilize ontology, a knowledge representation and reasoning approach, as the methodology to achieve the goal of identifying applicable safety requirements. In such ontology-based researches, the development and construction of the safety concept ontology is an essential task as the concepts and the relationships between the concepts both representing key safety knowledge need to be carefully identified. In this paper, the author focuses on the safety documents without predefined concept structure and aims to address the concept and relationship identification difficulties. Specifically, the author leverages the Formal Concept Analysis (FCA) methodology, a theory of data analysis that identifies conceptual structures among data sets, to mine and analyze the documents in order to discover safety concept structure and to further assist the development of the concept ontology for the construction safety documents. The author expects the application of FCA to construction safety domain can eventually benefit the ontology-based approaches for identification of applicable safety requirements.

Aug 1, 2013

By Chan-ho Park

As the building has recently become bigger, higher, and freeform, a technology called BIM(Building Information Modeling), which is a key technology that integrates construction and IT(Information Technology), has been rapidly introduced and expanded. Because BIM technology offers various benefits, countries that introduced BIM early has been actively promoted. However, misperceptions of BIM are prevalent in countries such as South Korea that have adopted it relatively late, with lack of awareness of its fundamental purposes. Under these circumstances, transparent and quantitative performance assessment needs to be executed in order to eliminate the misperceptions, and to explain and revitalize the BIM introduction. These quantitative performance measure KPI (Key Performance Indicators) to be measured should be prioritized. As derive performance indicators in terms of the four types (financial, customer, internal processes, learning and growth), and performance management systems, Uses the BSC to seek a balance between short-term financial goals, values and the value of long-term goals. Uses the BSC(Balanced Scorecards) to derive performance indicators in terms of the four types (financial, customer, internal processes, learning and growth), and performance management systems, seeking a balance between the value of short-term financial objectives and the value of long-term objectives. Through this, the KPI (Key Performance Indicators) which is used for measuring the effect of the BIM will be generated and also the method that can determine whether the generated KPI figures are objectively inter-connected will be suggested as well.

Aug 1, 2013

By L. Gawlik

Since the beginning of the 20th century, coal has been the world?s main source of primary energy. In the last few decades, consumption of coal has gradually decreased in some European countries and elsewhere due to the introduction of other energy sources. Regardless, industry continues to use solid fuels for energy production despite of their association with carbon dioxide emissions (about 7 billion Mg). For global development going forward, it is important to estimate what level of energy consumption can be expected as far into the future as the next few decades. To answer this question, specialized global institutions such as the International Energy Agency, the World Energy Council, the World Coal Institute, the U.S. Energy Information Administration, the International Institute for Applied Systems Analysis, as well as oil companies (BP, Shell), conduct periodic forecasts of world energy consumption. The development of such forecasts is very complex because their reliability is influenced by many factors that are difficult to estimate, such as economic development, population growth, climate change, and public awareness. We are all aware that the global demand for electricity will rise significantly in the coming years as a result of anticipated population growth, industrial development, rising living standards, and the general development of civilization. The world?s mineable resources in 2010 were as follows: coal 665.6 million Mg, brown coal 195.4 billion Mg, oil 163 million Mg, and natural gas 185.5 billion m3. The annual global primary energy demand in 2008 was more than 12 billion toe (12,267 Mtoe). In 2006, electricity production in the world amounted to 18,921 TW?h. The structure of the primary energy mix in TW?h (2006) was as follows: coal 41.0%; natural gas 20.1%; nuclear fuel 14.8%; hydro energy 16.0%; liquid fuels 5.8%; and other renewable energy sources 2.3%. The European Union (EU) is one of the largest coal consumers in the world. In 2010, the EU-27 produced 396.1 million Mg of brown coal, and 132.9 million Mg of hard coal; 188 million Mg of coal was imported from outside the EU. The largest hard coal producers in the EU-27 are Poland, Great Britain, Germany, the Czech Republic, and Spain; major brown coal producers are Germany, Greece, Poland, the Czech Republic, and Hungary. For many years, the Polish energy sector has been based on domestic fuel sources ? hard coal and brown coal. The characteristic feature of the Polish balance of primary energy resources is a very high share of coal ? much higher than the world average. Pursuing the decarbonisation of the Polish economy may jeopardize Poland?s energy security, leading to a significant increase in electricity prices, which would hamper the country?s economic development. Price volatility and supply uncertainty are now the dominant features of the international markets for oil and natural gas. The high share of these fuels in meeting energy needs is the reason for unrest in many countries, including those in the EU. Under these circumstances, coal may become the stabilizing element of EU energy security.

Aug 1, 2013

By Adam Jordens

Along with gravity separation and froth flotation, magnetic separation is one of the most common techniques for separating minerals. Minerals are separated by a magnetic force that is dependent on a combination of the applied magnetic field, the magnetic field gradient and the magnetic properties of the minerals themselves. Minerals may be classified as diamagnetic, paramagnetic or ferromagnetic based on the way they interact in a magnetic field. The magnetic susceptibility of a material may be determined by using a vibrating sample magnetometer to determine the magnetic moment of the material in an applied magnetic field and then converting this measured moment into the material?s magnetic susceptibility. In the case of rare earth minerals, magnetic separation is commonly used to remove ferromagnetic iron-bearing gangue minerals and to concentrate paramagnetic valuable minerals such as monazite and xenotime. These magnetic separation steps are frequently preceded by a gravity separation step as many iron oxides and rare earth minerals have specific gravities that are much larger than those of typical gangue minerals. By varying the magnetic field intensity it may be possible to use magnetic separation to selectively separate the paramagnetic and ferromagnetic minerals that report to the concentrate after gravity separation. Test work on a Canadian rare earth ore has shown that a gravity concentration step using a Knelson concentrator was able to selectively concentrate heavy magnetic minerals as evidenced by increased recoveries, relative to the Knelson tailings and fresh feed, after processing through a wet variable intensity magnetic separator. Mass pull to the Knelson concentrate was 4.5 % and the magnetic recovery of this concentrate, at 0.94 T, was approximately 40 % higher than the magnetic recovery from the Knelson tailings (70 % versus 30 %). The products of the wet high intensity magnetic separation were also analysed using a vibrating sample magnetometer to determine the magnetic susceptibilities of the various concentrate and tailings products.

Aug 1, 2013

By Patrick Cloutier

Presentation objectives ? Introduce discrete-event 3D computer simulation as a tool to design, improve and optimize construction projects: ? Describe a real typical construction project planning issue. ? Present an applied use of simulation to solve this issue. ? Detail benefits of using simulation versus traditional planning methods.

Aug 1, 2013

Some examples of the results of research projects, conducted in the KOMAG Institute of Mining Technology are presented. Special attention is paid to mining machines and equipment, and improving work safety and comfort of miners in underground workings. From numerous scientific and technical achievements of the KOMAG Institute within the last 2 years, a few design solutions have been selected for a presentation. Some results of European projects on innovative solutions are described as well, highlighting KOMAG?s role in the national and international research area.

Aug 1, 2013

By Andrew Bamber

The mining and beneficiation of minerals is the second largest end-use of electrical power on the planet, and comminution is by far the largest single contributor to this. Several jurisdictions, including British Columbia, have, in response to concerns about greenhouse gas emissions and climate change, adopted energy conservation legislation, including carbon taxes, carbon trading and conservation incentive schemes. Key to achieving conservation objectives is firstly an understanding of usage metrics across the various unit operations in the sector, and secondly an understanding of the conservation potential represented by available technologies and approaches in reducing end-use. This paper presents the results of a recent utility-funded study on energy use metrics and conservation potential at large open pit mines which are typical of the sector in BC.

Aug 1, 2013

By K. A. Mackinnon

The choice of fan type (axial flow, centrifugal or mixed flow) most suited for a mine ventilation application depends on a number of technical and economic factors. For each project, the relative importance of these factors will vary. It is worthwhile to carry out an assessment on a case by case basis. The paper, by discussing a number of technical and economic factors and their interactions, will provide the ventilation official a methodology to easily and methodically undertake such an assessment.

Aug 1, 2013

By J. G. Bennett

Coal consumption has increased globally by 57% over the last ten years. Underground mining typically provides coal of the highest calorific value and accounts for the greatest proportion of production. Despite a negative environmental image and indeed impact, this industry appears likely to thrive on the global scale for many years to come. Such mining consumes large amounts of electricity with implications for carbon dioxide emission at power plants and emits substantial quantities of the powerful greenhouse gas methane. In response to this significant carbon footprint, the European Union has funded research to examine the potential for a range of improvement technologies in a project entitled Low Carbon Mine Site Energy Initiatives (LOWCARB). Coal properties related to seams and mines, together with longwall characteristics, provide the basis for research into modelling optimally efficient methane drainage with a view to assisting mining as well as maximising electricity generation at surface and hence oxidation of the methane. Possible systems for the oxidation of very low concentration methane in ventilation air, which contributes the greatest greenhouse gas impact due to the volumes emitted, have been studied and modelled. Simulation and investigation of intelligent optimisation of electricity demand patterns provide the basis for reducing the demand peaks at mines and hence the cost and ultimately the carbon footprint of a mine, while specific investigations have been undertaken into ventilation efficiency at an unusually challenging mine and simulation of mine water pumping in order to develop an innovative method to monitor pumping systems efficiency. For post-mining use, the potential of disused shafts for compressed air energy storage to improve the operation of future electricity grids with high renewable energy penetration by reducing peak generation capacity requirements has been studied. While underground coal mining will always by definition be related to a significant carbon footprint, this paper provides an overview of a set of initiatives that can make a positive environmental impact while controlling costs across a huge global industry.

Aug 1, 2013

By Nicholas C. Williams

This paper presents the development of a demand reduction and responsive strategy capable of reducing the electrical power demand, particularly during peak conditions. The work presented includes a case study of a UK colliery. Areas explained are the equipment installation at the mine; the development of the demand reduction strategy including the load profile database and prediction optimisation model. Some live production data from the power meter installation at the mine is also presented.

Aug 1, 2013

By Mousa Mohammadi

Due to operational advantage of dragline in simultaneous excavation and back-filling, the equipment has gained vast importance in open-pit mining. Besides, absence of auxiliary haulage units and a myriad of other benefits are also credited in favor of excavation of muck piles by the draglines. However, the aspects of production, productivity and economics are of utmost significance in dragline operation and planning. In this light, the present paper is an endeavor to analyze availability and utilization of dragline operations. The paper presents a good amount of data for 4-draglines operating in one of the major opencast projects in India. The study reveals the trends of availability and utilization of these draglines during last 11-years. Furthermore, the study also highlights the salient reasons for loss of available hours and for idling of the draglines. Some startling information and facts have been illustrated in form of graphs and pie charts.

Aug 1, 2013

By I. A. Kovalevska

Considered problems: elaboration and implementation of resource-saving technologies, low-cost support systems improvement, openings security and support, based on wallrock condition control with supreme implication into the rock pressure occurrence counteraction work. Results of analytic and underground investigations using computer simulation of the finite elements in order to calculate stressstrain state of the multivariable geomechanical systems are presented. Solutions of concrete objectives are found using spatial geomechanical model of solid motion around openings, considering real geomechanical parameters formation of support forms with proper conditions of their contact and real mechanical characteristics. Ultimate solutions of resource-saving technologies implementation based on the analysis of multivariate vertical, horizontal, and reduced stresses components calculation and also near-contour rock, support bearing components and security constructions movements are found. Results of experimental investigations of combined supports and security constructions, which increase openings' stability in difficult conditions of flat coal seams are presented.

Aug 1, 2013

By R. Argane

In this work we assessed the geochemical behavior of concentrator tailings deposited at the abandoned mines of Zeida and Mibladen (Upper Moulouya, Morocco), using physico-chemical analyses, mineralogical characterization, acid base accounting and weathering cell tests. The aim of the study was to evaluate mine drainage quality and to assess metal mobility from these concentrator tailings. Chemical analyses show that the Upper-Moulouya abandoned tailings contain relatively high quantities of lead (0.261 to 0.594 % wt). Mineralogical analyses reveal the abundance of neutralizing minerals (calcite, dolomite, ankerite, and aluminosilicates) which influence mine drainage and metal mobility in mine tailings. Leachate analyses from weathering cell tests show alkaline conditions, small conductivity values, and low solubility of Pb-mineral phases. According to these results, abandoned mine tailings in the Upper-Moulouya district have very low potential for generation of contaminated mine drainage and for leaching of heavy metals. However, the inhalation of tailings exposed to winds generate dust problem facing the local population and may cause health consequences.

Aug 1, 2013

By J. Kalejta

Ever increasing depth of mineral extraction presents a challenging environment for hard rock underground mines. High in-situ stresses and associated seismicity with potential rockburst hazards are the major decisive factors contributing to the choice of a ground support regime. Conventional ground support systems, designed primarily for static loads, are not always capable of providing safe working conditions for underground personnel in seismically active mines. Systems specifically developed to resist dynamic loading and allowing for larger deformations are therefore preferred alternatives. High-tensile chain-link mesh has a proven record of successful use in open cut operations in various rockfall barrier installations due to its high energy absorption capacity. It has also been used in underground operations in various parts of the world. This paper describes a method of mechanized installation of a chain-link mesh evaluated at the Kiruna mine in Sweden and South Deep Mine in South Africa. A purpose-built mechanized roll mesh handler was used in this evaluation. The handler is compatible with all standard multi-boom underground drill rigs and is operated utilizing the hydraulic circuit normally used for the feed arrangement. A number of key performance indicators have been identified as success criteria: ??A 30-50% faster installation compared to the conventional methodology ??The mesh should sustain any blast damage when applied to the blasting face ??No unraveling of the mesh when cut ??No failure of mesh under normal conditions Although the energy-absorbing mesh combined with yielding rock bolts is a ground support system of choice for rockburst prone conditions, the operational upsides recognized during the evaluation imply that this product can also be competitively used in less demanding ground conditions where customarily weld mesh or shotcrete are used as a primary surface support. The main conclusion: a fast, safe and fully mechanized installation.

Aug 1, 2013