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By A. Tylczak, C. Norman, C. Shook, S. Loif

"There are a lot of good reasons to manage energy use at mining operations. Optimizing process energy use reduces operating costs. Tracking energy use can help identify unplanned process changes or malfunctioning equipment early, which allows problems to be corrected promptly.Sacré-Davey Engineering in Vancouver has performed over 50 Energy Management studies for various industries including: mining, pulp and paper, oil and gas, etc. Energy Management programs can be used to identify energy reduction opportunities, assess project feasibility, complete equipment selection trade-offs, as well as to monitor and manage energy costs. Benefits of energy management programs are reduced energy costs, reduced maintenance, and increased plant automation. Additionally, energy management can provide access to utility incentive funding and quantify savings which can greatly improve the return on investment of potential projects.Energy management studies are funded by many Utility programs across Canada. There are various programs available for existing plants energy audits, project feasibility studies, new plant design reviews and energy monitoring and targeting, etc. There are capital incentives available which can significantly reduce payback period.This paper discusses how energy management can be used to support mill/mine operations groups, maintenance programs, as well as expansion or green field projects. This paper will also provide an overview of Canadian Utility companies programs and how they can assist mining companies.IntroductionThere are a lot of good reasons to manage energy use at mining operations. Optimizing process energy use reduces operating costs. Tracking energy use can help identify unplanned process changes and identify malfunctioning equipment early, which allows problems to be corrected promptly."

Jan 1, 2015

It cannot be said that accurate and reliable ore reserve estimation is the fundamental of any mining operation success. Estimation techniques which are used to estimate the grade distribution of an orebody together with the assessment of uncertainty and risk have a vital influence on the success of any optimisation algorithm. Traditional estimation techniques such as kriging or inverse distance weighting are frequently used for assigning grade values to blocks. Various attempts have been made in order to compare geostatistical estimated methods for ore reserve estimation. This paper aims to evaluate the sensitivity of different estimation methods over changing the block dimension. For this reason, several block models with different dimensions were derived in Chador Malu iron ore mine which is located in 180 km northeast of Yazd in the centre of Iran. Each block model was estimated by different estimation methods such as nearest neighbours (NN), inverse distance (ID) and ordinary kriging (OK). The results of each estimation methods were compared against a control block file created by using the assay results of all blastholes drilled in the ore over four benches of the pit. The results signify that by estimating the large block size, no significant improvement occurred due to the employment of different estimation techniques. Furthermore, the grades estimated based on ID method is more reliable, but OK methods estimated more accurate tonnage.

Dec 6, 2010

By Arel B. McMahan

The U.S. Bureau of Mines investigated 21 mines, prospects, and mineralized sites in and adjacent to a 38,713-acre portion of the 255,058-acre Kingston Range Wilderness Study Area in 1983. The study area is 35 miles north of Baker, CA in the Mojave Desert. Mineral deposits in and adjacent to the study area are in altered carbonate rocks intruded by diabase sills near monzonite porphyry contacts. Monzonite porphyry forms the core of the Kingston Range and underlies about 70 percent of the study area. Sedimentary carbonate rocks are exposed in bands on the north and east boundaries and as isolated roof pendants in the southeastern portion of the study area.

Jan 1, 1986

By D. Kolymbas

A simple formula is introduced which allows the evaluation of dynamic pile tests. The following case is considered: The pile top is dynamically loaded by an impact. The velocity v of the pile top is recorded over the time. Let v1 and v2 be the first and the second maximum of this curve. Then, the pile bearing capacity (resulting from ideally plastic resistance at the pile wall and at the tip) can be set approximately equal to Z(v1- ½ v2), where Z is the impedance of the pile cross section. Due to the assumption of ideal plastic resistances, radiation damping needs not be taken into account. Material damping may be important in rate sensitive soils (such as clay, even if it is highly overconsolidated). A simple correction procedure for material damping is proposed.

Jan 1, 1989

By Simon D. Handelsman

?Artisanalmining ?Application of human energy (e.g. pick & shovel) directly to produce minerals ?majority no technical skills and lack adequate working tools ?Small-scale mining ?Application of modern technology for limited scale mineral production Significance of ArtisanalMining ?15 million people in artisanaland small scale gold mining ?55 developing countries ?Use of mercury damages health of 100 million people

May 1, 2006

By Hodjat] [Shiri

A 4-legged jacket structure was installed by an Offshore Installation Contractor (OIC) in the Persian Gulf. In addition to four open-end pipe piles, six conductors were installed by OIC. During the installation of the piles and conductors, some cemented layers were encountered, which had not been accounted for in the foundation design performed by an independent well known offshore geotechnical site investigation contractor (OGSIC). Six months later, the Drilling Company (DC) hired by Client to execute the wells, reported that all of the six conductors were presenting anomalies, such as vertical misalignments up to 10o and/or collapse of the conductors tip and mid height. The DC faced with serious problem in drilling of the wells and in spite of several times milling the conductors and spending 40 days unpredicted extra time, some of the routes could not be opened and Client lost millions of dollars due to direct and indirect associated costs and expenses. This paper presents a complete overview of all engineering, construction and specially geotechnical investigations and shows that how an inaccuracy in interpretations of the results of an offshore geotechnical site investigation as the main reason in this case study can cause serious damages to whole project with unbelievable time and cost impacts some times up to millions of dollars.

Jan 1, 2006

By Michel Doyon

Canadian Context: Exploration ??Space Exploration is within the unique mandate of the Canadian Space Agency ??Global partnerships ??Maintain close relationship with our partners ??New knowledge in S&T ??Retain and attract highly qualified personnel ??Participation in missions leads to design roles in industry and academia ??Collaboration between government laboratories, industry and academia

May 1, 2009

By G. W. Adams

Foreword While the literature on radium is voluminous, there is no single publication available from Canadian sources which attempts to cover at all fully the world radium industry. The comparatively recent developments in the Wilberforce area, and the consequent arousal of public interest in radium, seemed to call for the publication of such a paper which would be intelligible to the layman. To satisfy this apparent need, the writers submit this paper which contains material derived from various sources, and for which the writers make no claim of originality. Direct references are made throughout the paper to sources of information.

Jan 1, 1931

By Claude Deveau

"With ever decreasing feed grades, finer mineralogy and increased demand for product, it became obvious that a major step in equipment performance was required to reduce operating costs and increase production. Offsite testwork indicated that a Centrifugal separator was capable of recovering fine tantalum and that the newly developed C Series Falcon concentrator would be capable of replacing many pieces of aging equipment and provide improved performance. Further investigation led to the rental and the purchase of a Falcon C20 concentrator followed by a C10 to maximize circuit performance.Falcon Concentrators Inc’ s practice of working with the customer mirrors Tantalum Mining Corporation of Canada’s (Tanco) philosophy of continuous product development. This synergy honed valve design for continuous operation in a highly abrasive ore environment.Tanco has recently purchased two more Falcon concentrators for the recovery of additional tantalum from its spodumene circuit. These new units have additional user friendly operating features partially based on developments made at Tanco.The Falcon C Series units have enabled Tanco to maximize recovery of tantalum that was otherwise lost while using the original conventional gravity circuit."

Jan 1, 2000

By Juan Lizana

El presente trabajo describe el proceso del sistema de gestión estratégica en la mina San Rafael, Puno. En este sentido, la empresa como parte introductoria de sus operaciones, ha propuesto la solución integral, donde la herramienta principal son los índices de gestión por unidades estratégicas de negocio y los índices de gestión por unidad operativa, los mismos que permitirán evaluar el desempeño de su organización frente a sus metas, objetivos y responsabilidades. En este sentido, el establecimiento de este sistema busca crear una cultura en la organización, a través del seguimiento de cada uno de los índices, permitiendo a la alta gerencia y a los demás niveles ejecutivos de la empresa hacer control de gestión, así como una reducción de los costos operativos en el Área de Mina y mejoras en los resultados de voladura.

Sep 12, 2005

By Shaw-Shong Liew

This paper presents the processes of investigation, analysis, design, construction and monitoring of soil nail stabilisation work to facilitate a 14.5 m deep excavation at an uncontrolled fill ground. An extensive instrumentation programme had been implemented to monitor the performance of the stabilisation solution, to provide validation for the designed nail resistance and groundwater variation. From the monitoring results, it was proved that the soil nail stabilisation technique is effective for loose saturated fill provided that substantial care is taken during implementation. Construction difficulties, solutions to overcome the problems and lessons learned will be discussed in the paper.

Jan 1, 2006

By M. L. Free, L. Anthian

Electrochemical, chemical, and image analysis techniques were utilized together with statistical analysis methods to determine the effect of various anode impurities on copper electrorefining performance. Results indicate that arsenic is a beneficial anode impurity. Anode lead and sulfur are shown to decrease electrorefining performance. Specific emphasis is given to the influence of individual elements on current efficiency, slime particle generation, and cell voltage parameters.

Jan 1, 2000

By J. Muller

Keywords: Pyrometallurgy, blast furnace, slag viscosity, slag liquidus temperature, phase equilibria The viscosity of molten slag in blast furnace operations is an important process variable, influencing the rate and location of reactions inside the furnace, as well as the ease with which the final slag could be removed from the furnace. To optimize these processes, it is necessary to estimate the slag viscosity and liquidus temperatures as accurately as possible, and know the target values. Models to predict viscosities and liquidus temperatures, incorporating phase equilibrium calculations, have been developed and validated with measured data. Various diagrams have been developed to illustrate how the properties vary with composition and temperature, including pseudo-ternary diagrams of SiO2-MgO-CaO-Al2O3 for viscosity and liquidus temperature. Models were also applied and methodologies developed to analyse historical blast furnace operations and determine target values.

Jan 1, 2011

In New York City, on the walls of the library of the United Engineering Societies are these words:"Engineering-the art of organising and directing men and of controlling the forces and materials of nature for the benefit of the human race," but who, reading the schedules of even our best engineering schools, would infer that engineering is an art or that it should always havejn mind the benefit of the human race? While it must be remembered that our engineering schools exemplify the British cult of the amateur, that cult which lets men who have never attended a lecture on "Education" or perhaps nevereven read a book on it, become enginering teachers by profession (and so educators by inference), the root of the matter is to be found in the fact that our educational aims, and consequently our educational practice, seem suited much better to the position engineering held in the community in 1900 than to the position it holds to-day. This civilization of ours has developed, !;loth for good and for ill, into one based largely on engineering achievement; technical progress is so continuous and so rapid that thevalue of descriptive knowledge of current practice is ever lessening; enough must be imparted to make the young graduate immediately employable, and this amount is sufficient for illustrating the principles on which practice is based and on which its advance depends, but the young graduate's technical progress depends much less on his having acquired additional knowledge than on his ability to acquire knowledge, so, paradoxically, the more useful knowledge there is availabJe the less of it the student should be taught.Less conspicuous but fully as important is the enlargement of the field of work of engineering graduates, especially its extension to the initiating of policies and to the broader problems of administration. At present the road to such positions lies normally through a considerable period of professional work, but it is by no means unlikely that the field will soon include much that requires little professional expel'ience. At all events it is safe to say that the changed. and changing position of engineering in the communitydemands the attention of the engineering schools and that profitable discussion of engineering education demands some understanding of the real nature of education and of the part which engineering plays in the life of the community.THE NATURE OF EDUCATIONUnfortunately "to educate" supplies an example of how words degenerate in meaning; most people regard it as the equivalent of "to instruct"; a small number feel they have gone to. the root of the matter when they say...

Jan 1, 1941

By Jewel A. G. Gomes

Electrocoagulation (EC) has been performed with Al-Fe electrode system with changing polarity for the removal of arsenic from water. The removal process has been studied using ICP-AES and Anodic Stripping Voltammetry with a wide range of arsenic concentration (1-1000 ppm) at various pH (4-10) and residence times (1-60 min). Electrochemically generated by-products have been analyzed using XRD, FTIR, XPS, SEM/EDS and Mössbauer Spectroscopy. Results revealed expected crystalline iron oxides (magnetite (Fe3O4), lepidocrocite (FeO(OH)), iron oxide (FeO)) and aluminum oxides (bayerite (Al(OH)3), diaspore (AlO(OH)), mansfieldite (AlAsO4?2(H2O)), as well as some interaction between the phases. The amorphous or ultra-fine particular phase was also found in the floc. The substitution of Fe3+ ions by Al3+ ions in the solid surface has been observed, indicating an alternative removal mechanism of arsenic in these metal hydroxides and oxyhydroxides by providing larger surface area for arsenic adsorption via retarding the crystalline formation of iron oxides.

Jan 1, 2006

By J. P. Morris

"INTRODUCTION In the investigation being conducted by the Bureau of Mines concerning the production and utilization of sponge iron, it soon became evident that more information was needed regarding methods for determining the degree of reduction attained in the manufacturing process. Sponge irons made by different processes vary in physical characteristics and chemical composition, and a method of analysis that is suitable for one type is not necessarily applicable to all others. For example, the hydrogen-evolution method, which measures the volume of hydrogen evolved upon treating the sample with acid, accurately determines the oxygen content of some types of sponge iron. However, when the sponge iron contains combined carbon, hydrocarbon gases are also-evolved and large errors may result. Probably no single method will give accurate results in all instances, and for this reason it is desirable to have several reliable procedures available and to know the limitations of each.For measuring the degree of reduction, determination of either metallic iron or oxygen should suffice, although for practical application of sponge iron to the production of steel the oxygen content is more significant. After consideration of proposed methods of analysis in regard to their suitability for routine use and the probable influence of other substances, four procedures were chosen for investigation:(1) Mercuric chloride method.(2) Copper sulfate method.(3) Hydrogen-reduction method.(4) Hydrogen-evolution methods."

Sep 1, 1945

By Tariq B. Hamid

Deep excavation is commonly associated with construction of different deep below-grade structural elements (e.g., basement walls and slabs, tunnels, retaining walls, tanks, utilities, etc.) Deep Excavation Retaining Systems (DERS) are required when open cuts with safe slopes are not possible. Careful analysis, design, and planning of the DERS are required to provide safe below-grade construction and secure nearby structures from damaging effects that may result from the deep excavation. Selection and design of temporary or permanent DERS (e.g., soldier pile and lagging, sheet piling walls, secant pile walls, tie backs, etc.) can have significant impact on time, cost, and performance. In order to design DERS using conventional methods, it is necessary to obtain shear strength parameters, angle of internal friction (ø), and cohesion (c), of retained soils. Residual shear strength parameters (ø'res, c'res) obtained from drained direct shear tests and triaxial tests on saturated samples have been commonly used in practice for the analysis and design of DERS. However, there are cases where ground water table remains at or below the base of excavation during the design lifetime of DERS. In such cases, the soil above the ground water table is in an unsaturated state. Therefore, it is important to account for the unsaturated conditions of soils in order to optimize the design of DERS. This paper is focused on implementing the basic concepts of unsaturated soils mechanics including matric suction and soils-water characteristic curve (SWCC) to estimate design shear strength parameters of unsaturated soils (i.e., ø°, c', and ø') for the design of a cantilever sheet pile walls, a typical case of study of the DERS. The results of this study indicate that the determination of unsaturated soil strength shear strength parameters is simple. In addition, using unsaturated soil mechanics theories has an outstanding impact on the design of retaining systems.

Jan 1, 2006

By Christopher Mark

Severe dynamic multiple seam interactions can occur when active mine workings are subsided by underlying mining activity. The most dramatic events are usually caused by longwall mining or pillar recovery beneath open, overlying entries. But pillars in abandoned workings can also fail and cause subsidence and damage an overlying mine. This paper describes a case history in which an apparent ?pillar squeeze? in the abandoned workings of a lower seam was initiated during retreat mining in an upper seam. The event subsequently extended more than 1,500 ft and ultimately closed the upper seam mine. Analysis indicated that the pillars in the lower mine were adequately sized for the lower seam mining and were not affected by the initial development above them. When retreat mining in the upper seam had progressed several hundred feet, however, the pillars located directly beneath the pillar line were overloaded, and an extensive squeeze initiated in the underlying workings. The squeeze, in turn, subsided the overlying workings, causing widespread rib falls and roof instability. Previous examples of dynamic multiple seam interactions resulting from delayed subsidence of underlying workings have been reported in the literature. This is, apparently, the first recorded incident in which pillar recovery in an active mine triggered pillar failure in an underlying mine, which then triggered a dynamic interaction that impacted the active overlying seam.

Jan 1, 2012

By Thomas P. Mucho, Dennis R. Dolinar, Anthony T. Iannacchione

The Chestnut Ridge Anticline is a prominent structure in southwestern Pennsylvania, USA. This structure has brought two economically valuable limestone formations to the surface, where they are easily accessible to room-and-pillar mining. Nine active crushed stone quarries, an underground research facility, and one industrial facility currently operate along the linear trend that represents the axis of the anticline. The National Institute for Occupational Safety and Health (NIOSH) has identified significant variation in levels of horizontal stress within relatively short distances at shallow overburdens along the anticline. At one quarry, the horizontal stress is high enough to shear strata with a modulus of approximately 77 Gpa. Conversely, zones of extension were observed in parts of another quarry, indicating very low horizontal stress conditions. This study found that high levels of horizontal stress are to be expected in this very stiff rock formation and that local geologic and topographic structures are capable of altering the magnitude and possibly the orientation of the horizontal stress field.

By Tony Brunger, Abid O. Adekunte, George Munteanu, David Greentree

A number of novel solutions have been proposed in recent years as alternatives to props and tie-backs in deep excavation support e.g. Adekunte (2008), Deschamps et. al. (2008), Adekunte et al. (2010) and Adekunte (2014). A number of these non-standard restraining solutions involve the construction of permanent or temporary vertical or raking buttress piles that are rigidly connected to the excavation support wall at regular intervals along the wall run. This paper chiefly focuses on the design and construction of twin-vertical buttress piles as restraining systems behind or in front of embedded retaining walls. The system essentially relies on the push-pull mechanism that develops between the twin piles, to maintain the overall stability of the excavation support. The paper’s main areas of concentration include; finite element modelling, geostructural design, construction procedure, instrumentation and monitoring that are associated with the application of twin- buttress pile systems. These are supported with project details of three recently completed high-end luxurious residential developments in Greater London, England, on which the twin-buttress pile system was used to restrain the excavation support walls for the basements on the sites. The mode of application of the system varies across the three sites. While the system was adopted as a long term solution behind the retaining wall on one of the sites, it was designed and constructed for temporary use in front of the retaining walls on the other two sites. Instrumentation and monitoring results from all the sites show the non-traditional system to be safe and effective, whilst having significant beneficial effects on construction programme, sequence of works and project cost.

Jan 1, 2018