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By Christophe Bragard, Marte Gutierrez, Haotian Zheng, Michael Mooney

This paper proposes a framework for applying surrogate-based approaches to evaluate SEM construction, which can both benefit the uncertainty analysis in the design stage and real-time calibration during the construction process. The performances of four surrogate modeling approaches, namely back-propagation neural network (BPNN), support vector regression (SVR), random forest (RF), and polynomial chaos expansions combined with Kriging (PCK), were evaluated and compared. A variance-based global sensitivity analysis (GSA) was performed on the surrogate predictor to quantify the impacts of geotechnical parameters on the deformation responses induced by SEM tunneling. The Regional Connector Crossover Cavern project constructed in Downtown Los Angeles was set as the benchmark problem to demonstrate the efficiency and reliability of the proposed procedure.

Jun 13, 2021

By S D. Fox, P B. Swart

Statistics showing that mine rehabilitation is falling behind rates of disturbance continue to be reported in the media. Unfortunately, most reported statistics do not account for the large growth-cycle that mining in Australia experiences, where there are typically significant new disturbances with large portions of these areas not being available for rehabilitation for a number of years. Many commentators assert that better planning is required to ensure that rehabilitation will be able to achieve a safe, stable, non-polluting landform that meets the agreed post-mining landuse.This paper focusses on the revegetation aspects of mine rehabilitation and in particular the matters that need to be addressed in the planning stage so that revegetation success is ultimately able to be demonstrated to regulators and other stakeholders.CITATION:Fox, S D and Swart, P B, 2018. Planning revegetation for relinquishment, in Proceedings Life-of-Mine 2018, pp 113–115 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 25, 2018

By J Durbin

To effectively plan for closure, we must have an end-point in mind. To undertake meaningful rehabilitation, a post-mine land use (or uses) must be known. However, it is becoming more apparent that the end-point or “goal-posts” are shifting - and may continue to do so throughout the life of a mine. As well as being safe, stable and not causing environmental harm, post-mine land uses should always be sustainable, achievable within the given land capability, and they should involve stakeholders in their design and development.The majority of mines in Australia, and around the World, were historically expected to return disturbed land to either native ecosystem or agriculture/forestry practices. However, examples of highly successful final land uses suggest that today’s focus on closure includes not only minimising future liability and impact but also – and importantly – a move towards the creation of economic opportunity (Murphy and Heyes, 2016).CITATION:Durbin, J, 2018. Planning for (not so) final land use, in Proceedings Life-of-Mine 2018, pp 110–112 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 25, 2018

By Wilson Blake

This report presents the results of a 7-year Bureau of Mines program to review, revise, and make an effective engineering tool of the microseismic method of determining the stability of rock structures. The program consisted of developing new microseismic equipment and data analysis techniques and extensive field investigations to demonstrate the effectiveness and potential of the broad-band microseismic method. The guidelines for choosing the components of a microseismic system are presented along with approximate cost figures. Different microseismic systems are discussed, including completely automated systems. Procedures for conducting microseismic investigations and analyzing microseismic data are discussed in detail. Field situations which show the full value of the microseismic technique as an engineering tool are described.

Jan 1, 1974

By Vishal Pathak, Shailesh A. Godhuly

Ground Modification System in terms of Jet Grouting for soil strengthening and mass stabilization was engaged for a power plant project in an international power project, engineered by L&T-S&L. The site Geology consist of cohesionless type of sandy alluvial deposits (silty fine sand) as the main formation. Ground water table is encountered at shallow depth. Geological interpretation is done using soil investigation data along with CPT’s. This paper discusses design and implementation of jet grout technique to improve the mechanical behaviour of soil. To distribute load evenly from superstructure, a layer of growmast (drainage blanket) is laid above jet grout columns. Settlement evaluation is done using Finite element analysis with Plaxis 2D and Settle 3D. In the project, selected equipment foundations are resting on jet-grout columns including vibratory equipment like 144MW Gas Turbine etc. The project has been commissioned in September 2021 and operating with full capacity.

Sep 1, 2022

By A. CHESTER BEATTY

MAGNESIUM oxide is by far the most refractory of the common oxides, since it has a melting point of 5072 deg. F. as compared with 3110 deg. F., the melting point of silica (crystobalite) ; 3722 deg. F., the melting point of alumina (corundum) ; and 4127 deg. F., the melting point of chromite (Cr2O33FeO). Its large-scale use in the lining of metallurgical furnaces dates back to the latter part of the nineteenth century, when extensive deposits of magnesium carbonate were discovered in southern Austria in the province of Styria. Before the development of Austrian magnesite, calcined dolomite, a mixture of lime and magnesia, was used in basic steel-making furnaces. The lime in the dolomite was quite objectionable, since it slaked on exposure to the atmosphere, and dolomite therefore could not be made' .into permanent furnace bottoms or into brick. The Austrian magnesite, with its very low lime content, was free from these objections and soon displaced much of the dolomite. With the extensive development of basic steel-melting, the rise of the copper industry, and other metallurgical and chemical processes which dealt with chemically basic substances, the use of magnesite grain and magnesite brick increased rapidly.

Jan 1, 1931

By H. Lee

Recently, the effects of global climate changes have become top concerns for governments? decision making regarding infrastructure investments. Extreme weather events that exceed the capacity of existing systems have considerably increased in frequency, and the potential effects of changing trends in temperature and rainfall on infrastructure are difficult to ignore. It is essential for governments to estimate the costs and benefits of adaptation to climate change to properly assess the financial feasibility of infrastructure adaptation strategies. This paper proposes a framework for estimating the economic aspects of infrastructure adaptation to climate change. The framework is composed of three steps of implementation: establishment of alternatives for infrastructure adaptation, performance prediction of infrastructure using future climate scenarios, and asset valuation based on costs and benefits. The first step specifies target assets, their adaptability to climate change, and applicable adaptation technologies. The second step evaluates the effects of climate change on the performance of infrastructure. The last step determines the optimal adaptation strategies among various alternatives based on their net benefits. The framework reasonably incorporates future climate scenarios into the estimation processes for climate change effects and provides a basis for budget allocation for governmental infrastructure investments. The framework is expected to assist government decision makers in establishing adaptation strategies in a rational manner under uncertain future climate change.

Aug 1, 2013

By John J. Sammarco

Mining has one of the highest annual average fatality rates among major US industries. Health and safety dangers have been inherent to mining since the early days of picks and shovels. Even though miners' health and safety has improved over the years, mining is still one of the most dangerous occupations. Mining was traditionally a low tech industry. It is now driven by competitive pressures to go high-tech by using programmable electronics (PE) for machine control, atmospheric monitoring and material processing. The industry's experience with the functional safety of PE is limited compared with other industries. Thus, PE is an emerging technology for mining that can potentially create or worsen hazards. The US National Institute for Occupational Safety and Health (NIOSH), Pittsburgh Research Laboratory in Pittsburgh, PA is addressing the safety of this new technology. NIOSH has a proactive project to generate recommendations for addressing the functional safety of PE-based mining systems before the technology proliferates. The recommendations take the form of a safety framework encompassing the entire life cycle for a PE-based mining system.

By H. E. Wyslouzil

Column flotation technology was introduced to the market place about thirty ago years as a device capable of producing concentrates that were lower in impurities than those produced by other types of flotation machines. The ability to operate columns with significantly deeper froth beds and the provision of a froth washing system were the main reasons cited for the improved metallurgical performance. Column cells are now well accepted by the industry for cleaning applications, but there continues to be considerable skepticism about their use as roughers. There have been several documented cases of rougher installations which fell well short of predicted metallurgical performance. The reasons for the shortcomings vary from case to case, however they can be generally attributed to incorrect sizing, inappropriate application and or a lack of understanding of how column cells must be integrated into an existing plant or new project. Columns may not be the best choice for every application. In this sense, this paper discusses some of the important considerations that designers must take into account when contemplating the use of columns as roughers.

Sep 12, 2005

By Pierre Longtin

"Replacing the aging roadway access to the iconic Golden Gate Bridge, thereby ensuring traffic safety and robustness in case of seismic occurrences, provided an opportunity for major design improvements as well as the development of a parkway that would include the construction of four new tunnels. With an eye to the future, the Doyle Drive replacement project aimed to meet the highest standards for environmental stewardship beyond regulatory requirements. Understanding that lighting equipment is the tunnel‘s subsystem that uses the most energy, the operator was looking for a sustainable solution to light the tunnels. An Intelligent Lighting Control System (ILCS), designed specifically for road tunnels, was acquired to individually control the almost 2000 luminaires lighting the four tunnels. This paper will show the results in terms of energy and operational savings generated over the nine months of operation between the commissioning and the conference in April 2016. INTRODUCTION Electrical & mechanical (E&M) equipment represents an average of 10 % of a tunnel total construction cost. Once the civil infrastructure completed, E&M equipment drives the main part of the expense during a tunnel useful life. Table 1 below describes the impact of various types of energy consumption and their cost impact in tunnels of less than 500 m. It is clear that lighting is the sub-system that requires the most energy. A good lighting strategy is the key to reducing energy consumption due to lighting and a viable solution that will bring important savings in tunnel operations.With a price of $0.14/kWh in California and a planned increase between 3% and 6% per year during the period 2013-2040, the tunnel operators could not afford to overlit the tunnels—particularly when they have to operate it for the next 30 years. However, they also need to maintain the right lighting level to ensure driver safety all the time. The Presidio Parkway project includes the Battery tunnels, which are 240 m (790 feet) and 230 m (750 feet) in length, and the Main Post tunnels, which are 280 m (920 feet) and 315 m (1030 feet) in length."

Jan 1, 2016

By Charles F. Coleman

Kinetics studies and other rate measurements are reviewed in the amine extraction of uranium and of some other related and associated metal ions. Equilibration' is relatively fast in the uranium sulfate systems most important to uranium-hydrometallurgy. Significantly slow; equilibration-has ' been encountered' in some other systems. Most of the recorded rate information, both qualitative and quantitative; has come from exploratory and, process-development development work, while some kinetics studies have been directed specifically toward elucidation of, extraction mechanisms. In contrast to some other extraction systems, relatively little attention has been given to the kinetics of uranium extraction by amines. This is because investigators have not been troubled by slow extractions. Instead, when rate limitations have been of concern in amine extraction (Amex) process developments, they have been mainly from slow phase disengagement rather than from slow equilibration. Nevertheless, taking uranium together with several other elements that are closely related to it or associated with it in typical processes, a considerable body of rate information has been recorded.

Jan 1, 1979

"Some of the tools developed for the processing of nickel laterite ore by resin-in-pulp (RIP) may be applicable to the remediation of metalliferous mine drainage (MMD). In both cases, recovery of metal value and production of a stable waste stream appropriate for long term storage is desired. MMD typically has the additional challenge of management of toxic low-value metals. Seen in this light, innovations in RIP reactor configuration, selective elution strategies and novel synthetic ion exchange resins become useful tools for taking on the MMD challenge in a way that maximizes both environmental and economic benefit. INTRODUCTIONAcid mine drainage (AMD) is a common problem in any country with significant past mining activity. When sulphide containing minerals, tailings or slag are exposed to water, oxygen and sulphur oxidizing bacteria, AMD will result. Abundant and reactive iron sulphide minerals leach first, providing acidity and the ferrous/ferric couple that can enhance the oxidation kinetics of other minerals. If this runoff contacts encounters acid consuming carbonates or silicates, the acidity may be neutralized, but certain heavy metals remain in solution and can continue to be an environmental hazard (Gray, 1997). For this reason, the remainder of this paper will refer to the broader term metalliferous mine drainage (MMD) rather than acid mine drainage. In either case, such drainage, containing high heavy metal concentrations and often significant acidity, is toxic to aquatic life and can lead to significant damage to ecosystems and to public watercourses. MMD is a problem most commonly associated with now defunct sulphide mineral mines, but similarly toxic streams can result from many types of waste, such as poorly stabilized leach tailings, slag heaps, and coal flotation tailings (Johnson and Hallberg, 2005; Lee et al., 2002; Sainz et al., 2002; Schüring et al., 1997). In any case, the management and remediation of MMD is an important ongoing problem for the resource industry, particularly for the many mines in Canada closed before the advent of more stringent environmental standards. MMD remediation represents a significant long term expense for the resource industry. Multi-disciplinary efforts to understand and mitigate this problem range from creation of artificial wetlands (Poulin and Lawrence, 1996; Sheoran and Sheoran, 2006) to sophisticated biochemical reactors and precipitation processes (Hatami, 2010). Certain remediation technologies such as ion exchange offer methods to make a saleable product by recovering valuable dissolved metals. This paper will show how these technologies can help defray the cost of remediation, and offer potential to turn a dangerous waste stream into a useful product."

Jan 1, 2012

By W. J. Kogelmann

Roadheaders, also called Boom Miners or Boom-type Tunneling Machines have been in North America since 1968, when first introduced by Willy Kogelmann, the founder of Alpine Equipment Corp. (?Alpine?). Roadheaders were invented in Europe in the late 1940s. Machines with in-line, axial cutter heads were developed in the former Soviet Union. The British Dosco DRCL is based on the Russian PK-3 roadheader. Roadheaders with transverse ?ripper? cutter heads were invented in Hungary (1). The Austrian-made Alpine Miners of VOEST-Alpine, purchased by Sandvik AB, are based on a 1965 Hungarian license. Roadheaders are widely used in the mining and tunneling industries because they can excavate drifts, entries and tunnels with cross sections of any shape and size, can handle mixed faces, work on steep grades, and negotiate tight curves and cross-cuts. A roadheader?s only major limitation is the strength and abrasiveness of rock and minerals to be excavated. This paper covers roadheader selection criteria, improvements in reliability, attachments for flexibility (Multi-Tool Miner), and automated support systems for increased cutting time for increased shift production.

Jan 1, 2008

By Ö. Erdem

The investment decision making process in the insurance and finance industries is affected by new advances such as simulation techniques. These advances have improved the discounted cash flow method (DCF). In DCF, a dynamic and flexible model construction is not possible because it does not consider uncertain conditions. Each project should be evaluated taking into account the related uncertainties because the related uncertainties determine the characterization of the project. Related uncertainties can be processed in dynamic DCF, which is applicable to both financial and non-financial industries with different kind of uncertainties, such as power generation and petroleum projects. The dynamic DCF method can estimate net present value (NPV) while managing related project uncertainties with a simulation method like Monte Carlo Simulation. The simulation method is preferred because its output is unbiased. Therefore, a more realistic financial evaluation of the project can be concluded. In spite of the improvement of dynamic DCF, this project evaluation method is not used frequently in mining industry. However, the mining industry is ideally suited to this concept because it is highly dependent on estimations such as orebody size and ore grade. During the project evaluation stage, these uncertainties can be included with the dynamic DCF method. This study aims to contribute to increasing the usage of this method in mining projects. A copper reserve in Turkey is selected as a case study to apply uncertainty assessment for the evaluation of NPV.

Jan 1, 2012

By J. Gallagher

Henderson Mine has been transporting molybdenum ore using a rail haulage system for the past 21 years. Due to the age of this system, limited performance, and obsolescence, a capital investment decision was imminent. Henderson used this opportunity to evaluate other transportation methods and continuously improve their mining practices. These efforts resulted in a new mine plan for Henderson, which ensures that Henderson will continue to supply high quality molybdenum into the 21st century. This paper will discuss the dramatic changes taking place at the Henderson Mine as a new production level is mined. These changes include the installation of an underground crushing, conveying, and truck haulage system, as well as increasing the scale of the panel caving process. Each of these topics will be discussed, as will their rock mechanics and material flow implications.

Jan 1, 1998

By William Daly

THE application of artificial refrigeration, or air-conditioning, to the ventilation of deep, hot mines has long been a subject of interest to the operators of such properties. Artificial cooling of the air in theaters, railroad coaches, and various industrial plants has been so successful within recent years that it has been natural to assume that the adoption of similar methods would afford a ready solution to the difficult problem of mine ventilation. It should however, be obvious, that although there may be nothing technically impossible in the application of this process to mine ventilation there is a great economic distinction between the maintenance of a high standard of comfort for a large number of people in a relatively small space such as a theater and the cooling of air to improve working conditions for miners scattered throughout the extensive workings of a large mine. Many methods of air-conditioning have been considered by the management of the Anaconda Copper Mining Co. at various times, but until the development of the process to be described in this paper none has seemed economically practicable.

Jan 1, 1934

By Juan Ayza

La permanente exposición y concentración de polvo en la zona minera, han sido materia de múltiples enfermedades mortales para el personal que labora en ella. Tal ese así que el polvo de sílice libre es la causa fundamental de la alteración pulmonar llamada silicosis. Por tal motivo, el objetivo del trabajo revisa las propiedades de los polvos, los medios para detectarlos, indemnizaciones y los sistemas eliminadores de los mismos. En cuanto al sistema de producción, el polvo se extiende a través de laventilación, humedad, cargas eléctricas, entre otros, influenciando en el muestreo cuantitativo y en la creación de un método cualitativo de estudio, para complementarlo.Asimismo, se determina que el desarrollo de la silicosis se relaciona en el cuarzo como causa principal de dicha anomalía, aumentando el peligro de infección y la capacidad pulmonar. Para contrarrestar dicha enfermedad se busca soluciones alternativas como el uso del agua, aceita, una ventilación adecuada, los buenos hábitos en el trabajo, la floculación, el método porofliáctico de aluminio, concluyendo que el Hematocímetro es el más exacto y práctico de los anteriormente usados, dado su costo como su requerimento de instrumental menos complicado.

Jul 20, 1955

By E. Viljamaa

In this research, earlier developed information integration method and novel web technologies are applied to intensify infrastructure construction process control. The applied method uses semantic methods to integrate scattered information that is later on exploited by process management using state-of-the-art web technologies. The applied method and web technologies not only improve the process management situation awareness by integrated up-todate multi-source process data but also provide platform independent access and visualization tool for process data. Utilization of such technologies potentially lead on cost savings, make processes safer and also more environmentally friendly. The integration method also enables intelligent queries to the integrated data making possible to use machine based inferring to the data.

Aug 1, 2013

By V. Panayotov

Slag and by-products of metallurgy bear valuable components and their processing raises an in-creasing interest. Coke and iron have to be separated and other components have to be depressed, in order to obtain sellable high quality copper concentrates. Use of classical mineral processing technologies, such as magnetic separation, sulphidization, hydrometallurgy, etc. yields copper concentrates with grade of 4%~6% Cu. Copper is lost in tailings and the whole technological cycle is low profitable. Technology proposed applies an electrochemical treatment of the industrial water entering the flotation cycle. Iron and iron compounds that do not bear Cu, coke and gangue materials are depressed during the copper flotation. Copper concentrate of grade of 9.8%~10% Cu is obtained at simultaneous increase of Ag recovery by 8%~10%. As a result company profitableness is increased. Technology proposed is easy to implement, it does not require changes in the existing technology flow-sheet, and additional investment is low. The flotation process can be aided by a specially developed system for real-time analysis of the obtained copper concentrate which allows in-time corrections in the flotation parameters and entire process control. Applied flotation schemes, technological parameters and results obtained are described.

Jan 1, 2014

By Andrea Biagi, Elisa Comis, Gianluca Bella, Enrico De Panicis, Guido Barbieri, Matteo Giani

The Sotra Link Project is a major infrastructure project in Norway involving the design, construction, financing and maintenance of several underground and surface structures between Sotra island and the city of Bergen, among them 23 tunnel portals, 12.5 km of tunnels and a 900 m long suspension bridge. This paper describes the benefits in applying a Building Information Modelling (BIM) approach to tunnelling, from Early Design to the Detail Design Phase. The BIM application to the Sotra Link Project resulted in several improvements, such as efficient handling of clashes and inconsistencies, deeper understanding of effective design choices (reduction of errors), more efficient communication between designers, enhanced control of project quantities and costs. The advantages of the BIM approach during the ongoing Construction Phase are also explained.

Jun 23, 2024