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By A. R. House, G. W. Shepherd

Newmont USA Limited owns and operates the Phoenix Mine near Battle Mountain, Nevada, USA. The existing milling facility has operated since 2006 (House, 2010). Following the startup of the milling operation, and coupled with the upswing in the copper market, Newmont realized that Phoenix had no process option to treat transition and oxide copper ores. This meant that potentially revenue generating ore would be mined as waste. With no system in place to treat the transition and oxide copper, work began to determine the most feasible approach. After evaluating multiple options, the flow sheet was set for a runof- mine (ROM) heap leach pad and solvent extraction/ electrowinning plant (L-SX/EW). This paper will discuss the eight years of successes and challenges with developing the copper L-SX/EW plant and achieving commercial production of copper cathode.

Jan 1, 2014

By J. A. Scott, K. Moreau, H. Shang

"Trials of automated technology at underground mine sites around the world have reported increased production and the potential for lower energy consumption. Autonomous mining eliminates a range of delays related to operator downtime and travel to the workface and facilitates continuous operation in conditions that are unsafe for workers. Automation also introduces complexities and safety hazards arising from equipment–personnel interactions; automated processes must be isolated from other stope-cycle–related activities such as production drilling, development, loading, and backfilling, poten¬tially requiring changes to the mine design to maintain an efficient and safe operation. This paper reviews and discusses the implementation of automated equipment in deep underground mining operations and the challenges and advantages associated with the technology. ¦ KEYWORDS Automated equipment, Emissions reduction, Energy, Productivity, Sustainability, Technology, Underground mines RÉSUMÉ Des essais de technologies automatisées dans des sites miniers souterrains aux quatre coins du monde ont indiqué une production accrue et la possibilité de réduire la consommation d’énergie. L’exploitation minière autonome élimine tout un éventail de retards liés aux temps d’immobilisation des opérateurs et aux déplacements vers le front de taille, et facilite l’exploitation continue dans des conditions qui s’avèrent peu sécurisées pour les travailleurs. L’automatisation introduit également des complexités et des risques pour la sécurité, qui surviennent en raison des interactions entre l’équipement et le personnel. On recommande d’isoler les procédés automatisés des autres activités liées au cycle des chantiers telles que le forage de production, le développement, le chargement et le remblai, ce qui pourrait entraîner des changements au niveau de la conception de la mine afin de préserver rendement et sécurité dans l’exploitation. Cet article examine et aborde la mise en oeuvre de l’équipement automatisé dans des exploitations minières souterraines profondes, ainsi que les enjeux et les avantages associés à cette technologie. ¦ MOTS CLÉS durabilité, énergie, équipement automatisé, mines souterraines, productivité, réduction des émissions, technologieINTRODUCTION As the mining industry continues to exhaust easily accessible orebodies, the need for efficient, deep (typically below 2,500 m) mine operations increases (Atlas Copco, 2013a); however, the mining process can become economically infeasible at great depths because operation costs drastically increase. This has resulted in investigations into automating mining operations as the industry strives for improved productivity (Schunnesson, Gustafson, & Kumar, 2009) and ways to remove personnel from hazardous work areas."

Jan 1, 2019

By B. E. Halbert, K. T. Himbeault, S. L. Fernandes, R. L. J. Phillips, B. J. Topp

The Beaverlodge uranium mining and milling facilities operated from 1952 to 1981 with about 94% of the ore extracted from the main underground mine and 6% from smaller satellite deposits. Decommissioning work occurred from 1982 to 1985 involving periods of shutdown, salvage and reclamation. Transition phase monitoring, leading to eventual delicencing commenced in July 1985. Over the last 15 years, discharge from the tailings management facility (TMF) and a fresh water stream, impacted during the operational phase by tailings spills, has improved in water quality for most parameters of concern. Loadings to the environment of three key contaminants (radium-226, total dissolved solids, and uranium) have consistently been less than during the operational phase with radium-226 having the greatest variability. Outstanding environmental issues associated with the recovering drainage system formerly used for tailings disposal, are being addressed in an enhanced environmental monitoring program to commence in 2000. Changes in water chemistry and the natural re-introduction of aquatic organisms are issues of concern. In the meantime, application for release from selected satellite areas commenced in 1999. This paper reviews the issues which have arisen during the transition phase, outlines how they have and are being addressed, and provides a comparison of original and current predictions of the recovery process under way at the former Beaverlodge mine site.

Jan 1, 2000

By D. C. Fraser, W. J. Scott

"Airborne electromagnetic surveys were flown during 1965 in the Moose River area of Ontario. The systems used were INPUT Mark II and the Canadian Aero Otter. Anomalies indicated by both systems were located on the ground with vertical-loop EM. Two such anomalies were drilled, with no explanation being found in the bedrock geology. Subsequent seismic, resistivity and gravity surveys indicated that the sources of these anomalies lay in the overburden. Current work in the similar geological environment of the Winisk River area has shown that comparable AEM anomalies can still be misleading. The lesson to be, learned from these experiences is that additional geophysical work can help to resolve doubtful cases before drilling decisions are made."

Jan 1, 1973

By A. Taylor, E. Thorn Corthay, J. Farrell, L. A. Westfall, S. Borchardt

Mining and metallurgical industries need to minimize their greenhouse gas (GHG) emissions; Hatch specializes in conducting mining and metallurgical energy management assessments and optimizing productivity. Projects executed have demonstrated that there is a wealth of energy management, waste reduction, and process efficiency improvements that require no or low capital investment. Typical energy cost savings are on the order of 5% to 12%, with similar reductions in GHG emissions. Hatch generates Marginal Abatement Cost Curves to optimize the implementation pathway, maximizing carbon abatement and minimizing cost. The findings of a practical case study from Cameco are presented.

Jan 1, 2010

The Silvermines area of north County Tipperary in Ireland has experienced mining activity for over a thousand years, with lead, zinc, copper, barite and sulphur being extracted from a series of Carboniferous limestones. The last mine to operate in the area was closed in 1993. A legacy of contamination and derelict surface structures remain. Following the death of cattle in the vicinity in 1999, a governmental Inter-Agency Group was established to conduct an investigation. The ?Silvermines Rehabilitation Project? resulted, and included a proposal for the development of a Mine Waste Management Facility (MWMF) to act as a repository for waste materials from problematic sites across the area. The nature of the setting supported an effective solution from both a cost and performance perspective; and with limited maintenance requirements. Locating the MWMF where most wastes were identified would help minimise handling and relocation of materials. This position coincided with an area of artesian groundwater pressures. The resulting MWMF design consisted of a perimeter engineered embankment with the crest elevation designed to just exceed the groundwater piezometric surface. The base would remain unlined and groundwater permitted to rise up into and saturate the contained in-situ tailings deposits and imported mine wastes. The proposed system thus benefited from the ?wet cover? approach to minimising further oxidation of wastes and metal leaching, but without the usual accompanying outward hydraulic gradient and leachate management issues. A sub cap drainage layer with downstream outlet was incorporated to prevent any possibility of hydraulic rupture following an unexpected rise in groundwater heads. Leakage rates from the MWMF were deemed to essentially be driven by surface infiltration rates alone (characteristic of a ?dry cover? approach), with the proposed composite capping system simulated to perform at an infiltration rate of less than 1 mm per year. A toe drain was incorporated with the perimeter containment system, and this collection together with diverted neighbouring drainage was directed under gravity to a dedicated Passive Treatment System (PTS). Overall, effluent water quality from the PTS has been predicted to reflect an annual mass metals removal in the order of 95% below baseline.

Aug 1, 2013

By R. J. Allan

"CANADA HAS A GREATER LAKE AREA than any other country. Discountin the Great Lakes, this fresh-water area, mainly in the Canadian Shield, is listed as approximately 300,000 sq. mi. Densities of lakes range up to 7,500 in a 5,294-sq. mi. area of the Shield, southwest of Reindeer Lake, Saskatchewan. Five areas chosen randomly from the Shield (Figure 1) contained sufficient lakes to provide samples at a density of at least one per 10 sq. mi. Regional geochemical surveys in the Appalachian area (Nova Scotia, Boyle et al., 1958; New Brunswick, Boyle et al., 1966) and in the Cordilleran area (Yukon, Gleeson, 1965) of Canada and in many other areas of the world have relied heavily on analyses of stream sediments. These surveys show that sampling of material related to the drainage system reflects the over-all trace element content of the rocks and surficial deposits in the drainage basin. In the Shield, the classic types of dendritic (and other) stream systems found elsewhere in the world are very rare. However, impeded and disorganized stream systems that abound with lakes can provide the exploration geochemist with an ideal composite drainage system sample in the form of lake sediment. This paper attempts to demonstrate the feasibility of, and review the theory and problems involved in, the use of lake sediment as a regional geochemical exploration medium. Most of the references to field examples are taken from a regional survey using lake bottom sediment as the sample medium over 1,500 sq. mi of the Coppermine basalt group and adjacent rocks (Figure 2). During this regional survey, detailed sampling of several lakes was carried out and the results are referred to at appropriate places in the text."

Jan 1, 1971

By X. Zhou

"Hydrogen induced failure and degradation in structural metals, namely hydrogen embrittlement, has been a long-standing industrial problem for more than one century and remains unsolved. Despite the proposal of numerous models, no consensus has been reached, and considerable discrepancies in experimental observations and theoretical calculations exist. One aspect that is central to the understanding of hydrogen embrittlement is the interaction between hydrogen and grain boundaries. In this study, we investigated the influence of several solute elements (i.e., Cr, Mo and Nb) on hydrogen segregation at the representative 9 grain boundary using first-principles calculations. Our results showed that the presence of Mo and Nb can reduce the tendency of hydrogen segregation at grain boundaries, while meanwhile enhance the grain boundary strength. This indicates that Mo and Nb are salutary elements that can be used to increase the material’s resistance to hydrogen embrittlement, providing new insights in designing hydrogen embrittlement resistant Ni alloys. INTRODUCTION Hydrogen embrittlement (HE), a phenomenon of hydrogen triggering premature failures in structural metals, has been a headache for industries ever since its first discovery one century ago (Johnson, 1874; Zhou, Marchand, McDowell, Zhu, & Song, 2016; Zhou, Ouyang, Curtin, & Song, 2016). It is well accepted that the segregation of hydrogen at microstructures such as grain boundaries (GBs) plays a key role in determining the occurrence and severity of HE. GBs are two-dimensional defects where significant local lattice distortion exist, which leads to large free volume and thus locations for hydrogen trapping and segregation. Numerous works have clarified GBs as the energetically preferable places for hydrogen segregation. For instance, Geng et al. demonstrated the preferential segregation of hydrogen at the S5(120) GB in several metals, and suggested a decohesion-type of HE in light of Rice-Wang thermodynamic theory (Geng, Freeman, & Olson, 2001). Birnbaum et al. illustrated that complete intergranular crack of Ni GBs can be induced by hydrogen segregation when the hydrogen concentration is sufficiently high, evidencing the significant role of hydrogen accumulation on GB weakening (Lassila & Birnbaum, 1987). Yamaguchi et al. demonstrated strong segregation hydrogen also occurs at S3 GBs in alpha-iron, showing that local hydrogen clustering (i.e., multiple hydrogen atoms, up to six, per unit cell) can be trapped at the S3 GB (Yamaguchi, Kameda, Ebihara, Itakura, & Kaburaki, 2012)."

Jan 1, 2017

By C. H. Attwood

Introduction In presenting this paper on the water-power resources of the Province of Manitoba, it was considered that a brief resume of the power resources of Canada, of the power already developed, and its utilization in the industries 9f the country, would be of particular interest in showing the rapid progress that has already been made. Amongst Canada's national assets, water power occupies a foremost place because of the facilities it provides for the development of her other great natural resources. The rapid development of the mining, pulp and paper, and general manufacturing industries, and the concomitant growth in urbanization, with its numerous demands for domestic, commercial, and municipal service power, have combined to stimulate hydraulic development to a point surpassing even the most sanguine predictions of a few years ago. With the bringing into operation during 1928 of hydraulic turbines aggregating over 550,300 h.p., and of a further 378,400 h.p. in 1929, Canada's total hydraulic development at the end of 1929 amounted to over 5,700,000 h.p., and in this year, 1930, the active construction in hydro-electric plants throughout the country totals in excess of 1,600,000 h .p.

Jan 1, 1930

By S. Maleksaeedi

On-site evaluation of strength using hardness is common for different materials. The lack of such relation for aluminum alloys has always been felt. In this work, a finite element analysis of plastic deformation and its distribution in Brinell hardness testing is presented. The analysis has been performed for different strength levels of aluminum alloys. By utilizing the Von Mises equivalent strain in hardness, it is tried to derive a correlation between hardness and strength values for the alloys under consideration. The derived correlation is verified using the experimental values available in literature.

Jan 1, 2004

Risk management has taken on renewed vigor since the economic crisis of the late 2000s. The resources of governments, individuals, and corporations are being stretched to a point where only the most promising projects move forward. Risk management is a crucial part of the decision making process, yet it remains a broad term that includes disciplines from engineering to finance. A collaborative effort will be necessary to ensure that the most auspicious and appropriate projects are the ones moving forward. Risk management can be quantified to an extent by comparing the likelihood of an instance with the result of consequence of the instance occurring. In this manner it is possible to assign risk factors to instances and ultimately, begin to associate monetary value to the instance. Carbon sequestration is an emerging field that has a number of unique challenges. Risk management and mitigation must be an integral part of the overall picture. This begins with the planning and design phase, continues through implementation and production, site closure, and does not cease until termination of liability. The ability of carbon sequestration projects to successfully assess, mitigate, and recover from leaks will be a decisive characteristic of overall success. The costs of mitigation and failure will need to be analyzed on a test level, but will still need to be reliable enough to extrapolate to a commercial level operation. This paper will build a risk management profile based on case studies and field tests in Tennessee and Virginia. These tests are scheduled to commence in late 2013 and consist of small-scale injection tests in unconventional storage reservoirs with an emphasis on enhanced coalbed methane (ECBM) recovery and enhanced gas recovery. The ultimate goal will be to provide a clear and concise direction to move carbon sequestration from the test phase to commercial scale. While it is necessary from a risk management perspective to analyze all risk points, the scope of this paper will focus on pre-injection risk assessment for carbon dioxide (CO2) leakage potential. Despite the differences between the two tests, CBM compared to shale among other differences, a framework for analysis and mitigation can be developed pertaining to leakage risk. The probability of each type of failure will be assessed and analyzed, and plans to mitigate or reduce these risks will be reviewed.

Aug 1, 2013

By Larson. William

What is Lunar In-Situ Resource Utilization (ISRU)? ISRU involves any hardware or operation that harnesses and utilizes ?in-situ? resources to create products and services for robotic and human exploration In-Situ Lunar Resources ???Natural? Lunar Resources ??Discarded Materials Lunar ISRU Products and Services ??Excavation, Site Preparation, and Outpost Deployment/Emplacement ??Mission Consumable Production ??Outpost Growth and Self-Sufficiency Benefits of ISRU ??Increased science and exploration hardware (instead of consumables) ??Increased safety, crew exploration time, and self-sufficiency ??Technology spin-in/spin-offs help recycling on Earth & space economy

May 1, 2009

The principles and utility of in-situ coal gasification are discussed, and a first field test conducted by the Alberta Research Council in 1976 near Forestburg, Alberta, is described. The test was carried out in a 12-ft subbituminous coal seam under 60 feet of cover. Within this seam, a 30 by 60-foot block , containing approximately 650 tons of coal, was delineated by four injection/production holes which were oriented to take advantage of the natural fracture system in the coal. Linkage between holes was established by reverse combustion and gasification was accomplished by injecting air into the ignited coal. No steam was injected but operating pressures were adjusted to utilize formation waters for partial carbon -steam gasification. The coal gasification runs lasted six weeks and gasified an estimated 900 tons of coal ,' during sustained periods of gasification, a fuel gas with heating values of between 110 and 150 Btu/scf was obtained. Plans are now being developed for excavating the test site and inspecting the subsurface cavities created by gasification.

Jan 1, 1977

By Ernest Becker

Golder Associates provided overall radiological direction and assistance to the client in their interactions with the Canadian Nuclear Safety Commission and operational radiation protection services for the remediation of a calciner that had been used to process uranium. The project was somewhat unusual in that the radioactivity from within the calciner room was removed from the site and the cleaned steel recycled. The presence of yellowcake within the process equipment required stringent radiation protection measures. This project was completed successfully with minimal radiation exposures to the workers and the effective protection of the environment.

Aug 1, 2010

By V. V. Severov, Z. Lafhaj

The flotation separation of salt type calcium minerals is problematic, due to the similarities in their formation properties and the same active Ca2+ related site for interaction with anionic collectors and similar physicochemical characteristics such as solubility, point of zero charge, surface speciation, Ca-site density. The work was performed to achieve effective and selective separation of the calcium-minerals using pure minerals samples: four calcite, two fluorite, and two apatite samples. The effect of pure and mixing anionic collectors such as oleic and linoleic acid to different ratio (2:1; 1:1; 1:2) as well as the role of nonionic collectors on the selective separation of Ca minerals were studied. All flotation tests were performed in self-aspirated flotation cell. The results obtained with the blend of anionic collectors with the molar ratio of 2:1 show a separation between apatite and calcite at pH 5 and a ratio 1:2 at pH 9. The enhancing of separation contrast using the sodium silicate as a depressant for calcite and apatite is also examined as a function of oleate/linoleate ratio. Additionally, this paper discusses the enhancing of the selective separation of Ca minerals when anionic collectors were blended with nonionic reagents. The surface reactions in aqueous mineral suspensions and the adsorption of anionic collectors blended with nonionic reagents were studied by FTIR spectroscopy. An unexpected synergistic effect was observed for some ratios between anionic and nonionic reagents. The mixture of fatty acids and nonionic reagent showed very high flotation efficiency in comparison with fatty acid alone for the flotation of an igneous low-grade phosphate ore.

Jan 1, 2016

As part of the Australian Mineral Industries Research Association (AMIRA) P9 project, methods of characterising both the ore and the machines in flotation circuits have matured considerably over the past 15 years. Machine characteristics include gas dispersion measurements, such as bubble size, gas hold-up and superficial gas velocity. Ores can be characterised in terms of floatability parameters on a size and mineral basis. Measurements have been performed on various copper plants in many countries around the world over the last 5 years. This paper outlines the cell and ore floatability characteristics of each copper plant and provides a discussion on the differences between these plants. In general, most porphyry copper ore bodies are processed at high tonnage through several parallel banks of cells at each stage of flotation. The floatability parameters of these copper ores are very similar in terms of rate of flotation and proportion of fast, slow and non-floating material. The cell characteristics are also similar, with superficial gas velocity, bubble sizes, and gas hold-up values being of similar magnitude. Investigation of the similarities and differences of the modem copper flotation circuits has allowed an increase in understanding of the particularities of copper flotation. Comparison against other copper circuits provides a benchmark and opportunities for future optimisation.

Jan 1, 2007

By David A. Orava, Richard C. Swider

"The technical knowledge and practical experience accumulated by industry and others in abating acid mine drainage (AMD) is being proactively applied at every phase of the mine life cycle. This paper traces the mine life cycle from exploration to post closure monitoring and maintenance, and reviews AMD abatement measures that have become an integral component of exploration and mining activities.Attention is increasingly being given to evaluating AMD potential as part of exploration work, and studies related to project feasibility and design. Mining, mineral processing, and waste management options are selected taking into consideration their suitability to inhibit AMD. These inhibition measures are typically committed to in closure plans submit-ted at the permitting stage. Mines are operated and decommissioned, often progressively, as planned and in accordance with environ-mental protection policies."

Jan 1, 1996

By D. W. Hayley

The rapid expansion of exploration drilling with anticipated production facilities for oil and gas in the Mackenzie Delta region of the Northwest Territories has created a demand for granular construction materials. This paper discusses the technique adopted and experience gained by the authors from several major resource evaluation programs in this remote area. The first part of the paper describes a methodology for deposit identification, logistics of helicopter and ground-based drilling operations and the sampling difficulties which are unique to permafrost: soils. The second part describes the exploitation of a large glaciofluvial deposit at YaYa Lake on Richards Island. Granular construction material is sparse in the delta region relative to projected demand. Exploitable sources of granular materials for aggregates or construction borrow are found in glaciofluvial deposits of Pleistocene age or in outcrops of Paleozoic bedrock. Glaciofluvial landforms can be located by reference to published surficial geology maps coupled with airphoto interpretation. Preliminary assessment of these features in a large region is most economically carried out during the summer months with a drill that is transportable by helicopter. Once prospective borrow pit sites are identified, a detailed ground-based winter drilling program must be undertaken to establish aggregate quality and quantity, and to provide information on natural features which could affect development. The glaciofluvial terrain has been highly modified by the formation of massive ground ice within the gravel deposits. This presents some unique pit development problems which are not encountered in a normal bedrock quarry operation.

Jan 1, 1977

By Rong. G., T. Q. Lin, W. Du

Based on analysis of the evolutionary history of the valley in Baihetan, the mechanism of asymmetrical evolution, gradual migration-incision evolved from left bank to the right, is revealed in Baihetan river valleys. The process of in-situ stress evolution is carried out by using the Universal Distinct Element Code (UDEC). Consequently, the numerical results which indicate the main regulations of that stress field are as follow: (1) The phenomenon termed "high in-situ stress fold" appears in the bottom of the valley. With the maximum principal stress being 28-34 MPa, the stress increases significantly at a vertical depth of approximately 130 m. (2) The in-situ stress presents zonal distribution along the bank slope. It is apparent that the in-situ stress field consists of stress relaxation zone (SRZ), stress concentration zone (SCZ) and original stress zone (OSZ). The horizontal depth of stress relaxation zone varies from the left bank (roughly 200 m) to the right (about 120 m). Furthermore, the stress evolution of the left bank slope is studied. As a result, it is found that asymmetrical erosion contributes to the difference of the in-situ stress distribution as a critical factor, between the left bank and the right. And for an asymmetrical valley, the evolutionary process of in-situ stress field is a circular procedure, which includes the incision of valley, the accumulation of landslides and the migration of valley.

Jan 1, 2015

By Y. Wang

Phosphates and fluorides are used as regulators for the removal of silicates from diasporic-bauxite both in direct and reverse flotation. While using dodecylamine chloride as a collector, micro-flotation studies showed that sodium hexametaphosphate has stronger depressing power on diaspore than on silicate minerals with increasing sodium hexametaphosphate concentration at pH 6.5, but sodium fluorosilicate shows poor depression on diaspore with increasing sodium fluorosilicate concentration at the same pH. Zeta potentials of diaspore and silicate minerals become more negative both in the presence of sodium hexametaphosphate and sodium fluorosilicate. Adsorption density studies indicated that the adsorption density of sodium hexametaphosphate on diaspore is much higher than that on silicate minerals at the concentration of 75 mg/L. FTIR spectroscopy studies show that sodium hexametaphosphate interacted with the Al atoms exposed on the diaspore and silicate minerals surfaces to form P?O?Al bonds through the P02 groups. It is possible that sodium fluorosilicate interacted through F- or [SiF6]2- with silicate minerals surfaces based on the analysis by AES.

Jan 1, 2006