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By Roussos Dimitrakopoulos

Overview ?Uncertainty matters: The economic side ?Models of geological uncertainly ?Shifting the paradigm: Stochastic mine planning ?Using uncertainty to improve project performance ?Conclusions: Quantified uncertainty based models are great!

Oct 1, 2010

By K. Forsberg, A. Rasmuson, R. Rodriguez Varela, J. Martinez De La Cruz

"This study analyzes the separation of rare earth elements by means of a supported liquid membrane (SLM) with the final objective of recovering REE from an apatite concentrate (Alemrajabi, Forsberg, & Rasmuson, 2015; Mohammadi, Forsberg, Martinez de la Cruz, & Rasmuson, 2015). In this study, the feed phase consists of an aqueous phase containing REE, the membrane phase contains the organic solvent and carrier (D2EHPA and EHEHPA), and the stripping phase is a hydrochloric acid solution. An evaluation of mass fluxes, separation efficiency, and membrane performance is conducted. In order to analyze the suitability of liquid membranes in the extraction of REE, a deeper insight into the mechanisms causing instability is needed. In this study, surface tension is considered as the key factor of Marangoni instabilities and spontaneous emulsification.INTRODUCTIONThe demand of REE and their compounds has increased considerably due to their special physicochemical features that make them crucial elements for numerous high-tech applications, including wind turbines, hybrid cars, mobile phones, and defense technologies. They are also extensively utilized in traditional industries such as nuclear energy, petroleum, metallurgy, agriculture, and textiles (Xie, Zhang, Dreisinger, & Dyole, 2014; Zhang, Wu, Bian, & Zeng, 2014).Solvent extraction is widely used for the separation of REE (Xie et al., 2014; Zhao, Huo, Pan, Li, & Liu, 2014). Di-(2-ethylhexyl)-phosphoric acid (D2EHPA) and 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (EHEHPA) are two of the most effective extractants for the separation of rare earth elements among organophosphorus extractants (Gupta & Krishnamurthy, 2005). However, the difficulty in stripping loaded D2EHPA extractant, especially for heavy REE, has limited its utilization. Yttrium can be stripped at lower acidities in EHEHPA systems compared to D2EHPA systems (Gupta et al., 2005), but the extraction efficiency is lower. Conventional solvent extraction by mixer-settlers is restricted by its large solvent inventory and loading limits, and suffers from phase disengagement, emulsification, loss of solvent, and flooding problems (Swain, Jeong, Lee, & Lee, 2007). In this context, supported liquid membranes (SLMs) present a potential alternative due to their advantages, being low solvent inventory, process simplicity, low energy and operational costs, great enrichment ratio, and combination of extraction and stripping into one single step. A SLM is a system in which two aqueous phases are separated by an organic liquid membrane suspended in the pores of a porous support by capillary forces. One of the aqueous phases is the feed solution with the solute and the other is the stripping or receiving solution. The solute diffuses through the liquid membrane and then is extracted into the stripping solution (Kislik, 2010)."

Jan 1, 2016

By B. Grinbaum, A. Mazuelos, F. Carranza, N. Iglesias, M. Avila, J. L. Lozano, G. Perez, R. Romero, M. \/aliente

Following a failure of a tailings pond darn at a mine in Andalusia, Spain, a huge effluent stream, that contained about 1 g/1 Zn and significant amounts of ferrous, ferric, calcium, copper, aluminium and manganese cations has to be treated, to prevent pollution of a nature reserve. EGMASA, as the regional government environmental agency, suggested to improve the current depuration process by recovery of the Zn from the effluent. A solvent extraction (SX) followed by electrowinning (EW) was proposed and developed to remove zinc.. A pre-treatment stage consisting in bio-oxidation of ferrous iron by using a bacterial process followed by an alkaline precipitation was employed because iron in the effluent is incompatible with both the SX and the EW processes. The SX process was developed successfully at the laboratory scale and verified in a pilot plant on-site, using two Bateman Pulsed Columns for extraction and stripping of zinc. The results were satisfactory obtaining a recovery of 90% of Zn. The process was suitable for industrial application.

Jan 1, 2008

By G. Ozbayoglu, Z. Ozdemir

Turkey is the main boron minerals producing country in the world. The most important boron minerals are tincal, colemanite and ulexite. All mining, beneficiation and handling operations generate fines which cause ecological and economical problems. Utilization of this accumulated material requires both upgrading and agglomeration. The aim of this research was to exploit the ulexite fines by improving their grade and size. Attrition-scrubbing followed by washing and screening was employed for upgrading the fines. It was found that the grade can be increased from 23-25% B2O3 to 29% B2O3 with 73% recovery. Briquetting was applied as the size enlargement process. During the briquetting, the effect of moisture content, pressure, amount and type of binder, and drying on the quality of briquettes were investigated. The tests showed the possibility of production of strong briquettes by adding water alone, but the briquettes had no resistance to abrasion and water. Binders, namely boric acid and borax have been added to improve the properties of briquettes. The results showed that the compressive strengths and abrasive resistances of briquettes obtained with both binders were acceptable. However, the briquettes have no water resistance properties.

Jan 1, 2004

By James R. Hein, Jane Reid, Robert W. Embley, Se-Won Chang, Randolph A. Koski

"Abstract - This is the first reported occurrence of an active hydrothermal field in an oceanic fracture zone setting. The hydrothermal field occurs in a pull-apart basin within the Blanco Fracture Zone (BFZ), which has four distinct mineral deposit types: (1) barite mounds and chimneys, (2) barite stockwork breccia, (3) silica-barite beds, and (4) silica, barite, and Fe-Mn oxyhydroxide in sediments. All deposit types contain minor amounts of sulfides. In barite stockwork, silica-barite beds, and mineralized sediment, Ba, Pb, Ag, S, Au, Zn, Cu, Hg, Tl, As, Mo, Sb, U, Cd, and Cu are enriched relative to unmineralized rocks and sediments of the BFZ. Fe and Mn are not enriched in the barite stockwork or silica-barite beds, but along with P, Co, and Mg are enriched in the mineralized sediments. Silver contents in deposits of the hydrothermal field range up to 86 ppm, gold to 0.7 ppm, zinc to 3.2%, copper to 0.8%, and barium to 22%.Mineralization occurred by diffuse, low to intermediate temperature (mostly <250°C) discharge of hydrothermal fluids through pillow lavas and ponds of mixed volcaniclastic and biosiliceous sediments. Bacterial mats were mineralized by silica, barite, and minor Fe hydroxides, or less commonly, by Mn oxyhydroxides. Pervasive mineralization of bacterial mats resulted in formation of silica- barite beds. Silica precipitated from hydrothermal fluids by conductive cooling and mixing with seawater. Sulfate, U, and rare earth elements (REEs) in barite were derived from seawater, whereas the REE content of hydrothermal silica deposits and mineralized sediments is associated with the aluminosilicate detrital fraction. Fe-, Zn-, Cu-, Pb-, and Hg-sulfide minerals, Ba in barite, and Eu in all mineralized deposits were derived from hydrothermal fluids. Manganese oxides and associated elements (Co, Sb, Mo, W, Cl, and Cu) and Fe oxides and associated elements (Be, B, P, and Mo) precipitated as the result of mixing of hydrothermal fluids with seawater."

Jan 1, 1999

By Horatio Sam-Aggrey, Margot Hurlbert

Small Modular Reactors (SMRs) have been touted as having the potential to spearhead a nuclear renaissance. Proponents of this view cite the relative advantages of SMRs over larger nuclear plants as reason for their optimism. Some of these merits include potential economies of mass production deriving from modular factory production, enhanced safety features, the ability to locate reactors in remote areas, and reduced requirements for technical workforces to install and maintain SMRs. Despite the optimism surrounding SMRs, nuclear power is still a contentious issue for many Canadians. The growth of nuclear power remains adversely affected by concerns over issues such as: the health and safety consequences of nuclear power generation, environmental impacts, proliferation of nuclear materials, terrorism, and radioactive waste disposal (Organisation for Economic Co-operation and Development (OECD) and Nuclear Energy Agency (NEA), 2010). Personal values, past nuclear accidents, and lack of trust in the industry are other factors influencing attitudes toward nuclear energy (IAEA, 2005). In Canada, three main areas where SMRs could be used have been identified. These include: a. Traditional, on-grid power generation, especially in provinces looking for zero-emissions replacements for CO2-emitting coal plants. B. Remote off grid communities that currently rely on diesel or fuel oil power generation. There are 279 off-grid communities in Canada, many of them being Aboriginal communities (NRCan, ND). Notably, all communities in each of Canada’s three territories qualify as remote. C. Resource extraction sites, such as mining and oil and gas extraction sites. Many of Canada’s principal producing mines and active mineral exploration projects are located within close proximity of Aboriginal communities. Any proposed implementation of small nuclear plants would, require the support of the local population, which is largely Indigenous in the northern regions. The possible deployment of SMRs raises important issue relating to consultation and accommodation of Aboriginal concerns regarding potential SMR deployment. This is especially pertinent given Canada’s pending implementation of the provisions of UNDRIP. One of the provisions of UNDRIP that has attracted a lot of attention is the one on Free Prior and Informed Consent (FPIC). Drawing on previously published information, this paper discusses some of the challenges posed by FPIC for the deployment of SMRs. The next section outlines the provisions of FPIC and its implementation in the Canadian context. Section 3, details some of the challenges posed by FPIC to the deployment of SMRs, while Section 4 provides some concluding comments.

Jan 1, 2020

By David Stone

North American Palladium is the owner/operator of the Lac des Iles mine located 115 km north of Thunder Bay, Ontario. The mine has produced an average of 65,000 ounces of palladium since 1994. Lac des Iles is currently undergoing the first phase of a major expansion that will increase ore production from 2,400 tons per day to 15,000 tons per day. A future expansion is being contemplated for 30,000 tons per day. The current expansion will increase palladium output to 250,000 ounces per year. The mine plan for the ultimate pit results in an excavation 1 km long by 800 m wide and over 450 m deep. This makes the ultimate pit at Lac des Iles one of the ten deepest open pits in the world, and the largest in Canada. This paper outlines the geotechnical data collection and design methodology for the ultimate open pit at Lac des Iles.

May 1, 2001

By Keith Donovan

Why are we here? Improve equipment performance & health ? Eliminate undesirable downtime and expensive secondary damage ? Maximize equipment life, optimize running costs (reduce costs) ? Improve safety and environmental performance ? Capture and consistently apply equipment knowledge ? Improve Proactive Maintenance processes & practices

May 1, 2009

By Dallas Bienhoff

Boeing Study Team Participants Andrew Daga & Associates American Aerospace Advisors Hamilton Sundstrand Harris Honeywell ILC Dover Lunar Transportation Systems Oceaneering Orion Propulsion SICSA Thin Red Line USA LSSCA BAA Topic 2: MFHE Definition Minimum Functionality Habitation Element Deployable Habitat DHE Update The Path to Growth

May 1, 2013

By Roger K. M. Bellows

The last coal-fired power plant to be built in Canada came into operation in 1994. Since then, Canada?s electricity requirements have grown substantially but no new coal-burning plants have been built. This country has abundant resources of coal from coast to coast, but in recent years, this has not affected our choice of fuel. In many other countries this is not the case, and the use of coal is growing rapidly. Although this presentation covers the topic from an Alberta perspective, some of the conclusions can be extrapolated to the rest of the country, and perhaps even to other countries. The coal found in the Alberta plains is particularly attractive because of its low cost and low sulphur content. Yet coal is no longer the fuel of choice, and a long-standing provincial government policy to favour coal for electricity generation has been ignored for more than a decade. Considering the lack of good alternatives, it seems obvious that we should look to coal as our primary energy source in the generation of electricity and for other industrial applications. This paper discusses some of the reasons that coal has fallen out of favour, particularly with respect to electricity generation. The significance of the deregulation of the electricity industry will not be ignored. In addition, the author will offer his opinion on the question of what it will take in order for coal to once again become the favoured fuel.

May 1, 2001

By W. H. MacLean, S. Liaghat

The Key Tuffite is a thick (0.3 m to 6 m) and laterally extensive (-10 km) cherty, sulfide-bearing tuff unit in Archean greenstones in the Matagami mining district in northwestern Quebec. It lies at the contact of the Watson Lake Group and overlying Wabassee Group volcanic rocks, and is host to major Zn-Cu volcanogenic massive sulfide deposits. The tuff component is highly altered and its volcanic precursors are not identifiable by petrographic means. The tuff is mixed with a volcanic exhalative component comprising chert, carbonate and sulfides (pyrite, pyrrhotite, and minor sphalerite and chalcopyrite). The normative mineral composition of the Key Tuffite is 33% quartz, 28% sulfides, 16% sericite, 8070 carbonate, 6% chlorite and 9% other minerals. In the vicinity of the Bell Allard and Orchan mines, the precursor tuff components are identified using immobile major and trace elements, as Watson Lake tholeiitic rhyolite (Zr/Y = 1.5 to 3.5, LaN/ybN = 1.7 to 2.8, SiO2 = 72.5 ± 1.2 wt %, and Wabassee calc-alkaline andesite (Zr/Y = 9, LaN/YbN= 4 to 8, SiO2 = 56% to 65%). Immobile element computation techniques were used to calculate mass additions and losses in the conversion of the tuff to the Key Tuffite. Average net amounts of FeP3 (27% total iron), Si02 (14%), Cao (8%), S and K2 (+ 2%), were added, Nap was removed (-2.8%), and MgO was over-all unchanged. Total net mass change was +63%, which comprises mainly exhalative additions, but also includes changes owing to hydrothermal alteration of the tuff component.

Jan 1, 1992

By H. Wotruba, J. Heizmann

"The use of shotcrete is a mandatory means for rock support and therefore for safety in many underground mining operations. If shotcrete gets into the flotation feed though, it can negatively influence the flotation process. This especially occurs when sublevel stoping, cut-and-fill or room-and-pillar methods are applied because as the mining face moves on, formerly applied shotcrete layers are mined together with the ore.As shotcrete does not differ significantly from fluorspar ore in its physical properties it gets moved through the comminution process and is fed to the flotation plant like the ore. To prove the influence of shotcrete on the flotation process, a laboratory test series was conducted at the Unit of Mineral Processing (AMR) of the RWTH Aachen University. The shotcrete grade of the flotation feed was varied between 0 and 10% through addition of pure shotcrete. Flotation parameters and also reagent dosage were held constant apart from the addition of the pH regulator, which was dosed to reach a constant pH of 8 at the flotation start. Results showed that with increasing shotcrete grades in the flotation feed the fluorspar recovery as well as general mass recovery decreased. The enrichment factor of Fluorspar also decreased with increasing shotcrete grades in the feed.In an effort to eliminate the shotcrete contamination of the flotation feed, a feasibility study for use of sensor-based sorting prior to the comminution process was conducted. Rock sorting not only reduces the bad influence of shotcrete on the flotation process, but also reduces comminution costs. INTRODUCTIONShotcrete is used in underground mining on a regular basis. It is used for rock support and therefore to increase safety in the underground mining environment. In mineral processing the presence of shotcrete can cause difficulties for example in the concentration processes. In flotation the highly sensitive reagent mixtures can be disturbed by the chemical activity of shotcrete and therefore recovery rates and selectivity of the process can suffer.Shotcrete is a special form of concrete which is applied pneumatically with high velocities and is compressed by its impact energy. Since the process is especially suitable for work in difficult environments and overhead areas, it is established in underground mining for many years. Shotcrete is not only applied in pre-processing of the mines, but particularly of use for cut and fill, as well as room and pillar mining methods. There it is used to secure excavation chambers. When the mine face is secured with shotcrete and subsequently the mining continues, the applied shotcrete will automatically be mixed with the ore."

Jan 1, 2016

By M. Kataoka, Y. Obara

It is known that compressive strength and tensile strength of rocks vary significantly with specimen size. Rocks are composed of crystals and grains in a fabric that includes flaws such as microcracks, grain boundaries and pores. As the likelihood of including severer flaws becomes greater for a larger specimen, the strengths are small. On the other hand, the size effect in the fracture toughness of rocks has not been made clear until now because there are few studies focused on it. In this paper, Semi- Circular Bend (SCB) test was performed using Kimachi sandstone with various specimen sizes. A shape of the specimen is a semi-circular disc with an artificial notch. The specimens were prepared with various thickness t and radius r as the following two groups; t was changed from 10 to 37.5 mm with r = 37.5 mm in the specimen of group (a), and r was changed from 12.5 to 150 mm with t/r = 0.8 in the specimen of group (b). As a result, there was no significant change in the fracture toughness with different t. On the other hand, the fracture toughness increased with increasing r and converged on a certain constant value in a range larger than approximately 70 mm of r. Consequently it was clear that the size effect in the fracture toughness of the sandstone exists.

Jan 1, 2015

By Seongki Lee

The purpose of this paper is to propose the real-time facility management system framework based on Building Information Model (BIM) and Web of Things. Latest IT such as BIM is rapidly spreading to architecture, civil engineering, engineering and maintenance with the aim of simplifying complex system in buildings and facilities, minimizing operation cost, providing high value services and advancing facility management. In particular, BIM-based management framework design to assist the development of sensor information operation system, which adds convenience to facility maintenance and management, has emerged as a key issue. To this end, this paper proposed conceptual framework for data warehouse, web service and interface that make up real-time facility management system. The paper also produced conceptual methodology on CoRE-based web service platform, mobile device, BIM and WSN mapping.

Aug 1, 2013

By M. B. Greyver

The results of laboratory tests on iron precipitation from non-decopperized nickel anolyte are discussed. The parameters (pH, oxygen consumption and stirring speed) for iron precipitation from the anolyte, using the oxygen in the air, were determined. In the experiments conducted under optimized conditions, the residual concentration of iron in the anolyte after precipitation was 0.7-2.7 mg/L, and the copper and nickel losses to the solid phase were 0.05-0.07% and 0.05-0.16%, respectively. The filtration ability of the iron slurry obtained was 2 to 5 times higher as compared to that after chlorine oxidation and oxyhydrolysis. The leaching of the non-ferrous metals from the iron cake made using the separate nickel anolyte purification process was possible by dissolution in sulphuric acid. It was established that after cobalt precipitation from the copper- and iron-depleted anolyte, the precipitates obtained had lower ratios of Fe:Co and Ni:Co.

Jan 1, 2006

By David Sanscartier, Elizaveta Petelina, Alexey Klyashtorin

This paper provides an overview of the radiological risk mitigation approach applied by the Saskatchewan Research Council (SRC) for the remediation of 35 legacy uranium mine sites in northern Saskatchewan where uranium exploration and extraction took place in the 1950–60s. Mining activities resulted in an irregular increase of the gamma radiation dose rate (up to 18 μSv/h). The radiological objectives for the sites include a gamma dose rate at a spot (<2.5 μSv/h above local background), and the dose rate averaged over a hectare (<1 μSv/h above local background). These objectives are generally achievable at the impacted sites through the installation of shielding soil cover. This method may be impractical for site areas with rough terrain (e.g., steep slopes) and/or difficult access. A risk assessment approach is applied to determine if these areas can be safely left uncovered or if additional mitigation measures should be implemented. The risk assessment approach is based on two factors: (i) the ambient radiation dose rates collected through gamma surveys, and (ii) actual land use data collected through various surveys of activities of local community members at the sites. Exposure scenarios based on four land uses are applied to estimate a potential annual dose load for members of the public. The estimated doses are compared with the criterion of 0.3 mSv/a recommended by the Canadian Guidelines for the Management of Naturally Occurring Radioactive Materials (NORM). If the criteria are not satisfied, a mitigation plan is developed, and post-remediation gamma levels are modelled using GIS tools to evaluate the performance of the proposed mitigations. The proposed approach allows the team to optimize resources for the site remediation so that public exposure to NORM are as low as reasonably achievable after remediation.

Jan 1, 2020

By J. E. Dutrizac

Canada is currently the world&apos;s largest supplier of zinc concentrates and is also a major producer of zinc metal. This dominant position in the world&apos;s zinc market is a fairly recent circumstance and, in fact, the country&apos;s zinc industry was founded only in the early part of the twentieth century. By contrast, the American zinc industry was well established by the mid-nineteenth century, largely based on technology originally imported from the still older European practice. Initial attempts to create a viable Canadian zinc smelter were based on the traditional practice and were unsuccessful; success came only with new electrolytic technology, much of which was developed domestically. The purpose of this paper is to outline the early attempts to produce metallic zinc in Canada and to trace the gradual development of these first efforts into a viable zinc industry based on modern science and technology.

Jan 1, 1999

By P. E. Cavanagh

FOR THE PAST seven years Mr. W. Simpson, Chief Mechanical Inspector for the Nova Scotia Department of Mines, has carried out exhaustive field trials of non-destructive inspection equipment in the coal mines of that Province. This work has demonstrated the usefulness of a number of types of non-destructive inspection when used for periodic inspection of hoisting and haulage equipment in the coal mines of Nova Scotia. As a result, the Dominion Coal Company has instituted a programme of regular preventive maintenance inspection ?by a special staff of qualified and trained men. The purpose of this present paper is to describe how non-destructive testing techniques are used on ropes, axles, couplings, and other hoisting and haulage equipment, how these methods are being used in other industries, and the expected benefits from intelligent and properly organized use of these techniques in the coal mining industry.

Jan 1, 1956

By L. E. Djingheuzian

ANON-CATARACTING (N-C) ball mill is so operated that the balls are not thrown in-ward at the top of their paths. The result is to maintain, in the mill, a quiescent pool in which classification will occur at a limiting size corresponding to the pulp density. N-C operation is produced by effecting proper relationship among mill speed, ball diameter, volume of ball load, and pulp density. Such operation is typified by the primary ball-mill operation of the Tennessee Copper Company, Copper-hill, Tenn., and the Cleveland Cliff Iron Company, near Ishpeming, Mich.

Jan 1, 1958

By L. M. Dwarkin

Strip mining in Western Canada, though of considerable importance, is a fairly recent development for many of the operators in the district. Adding to the difficulty of unfamiliarity is the fact that a great deal of the stripping is done on pitching seams, for which the engineering and economic principles of setting the most advantageous strip ratio are not readily apparent. The novelty of the operation combined with the complexity of the principles involved can easily lead to misconceptions as to the determination of the economic ratio. Definition of Strip Ration There are two commonly accepted meanings of the term strip ratio: (1) The ratio of feet of overburden to be stripped per foot of coal recoverable. (2) The ratio of cubic yards of overburden per cubic yard or ton of coal. The first definition is inapplicable to pitching seams so, throughout this paper, strip ratio will be taken as the ratio of cubic yards of overburden to be removed per cubic yard of coal recoverable. Economic Ratio In the case of flat seams, the strip ratio is fixed by existing natural conditions, and the magnitude of this ratio determines whether stripping is economically feasible. With pitching seams, however, the strip ratio is a variable. On the outcrop, there is usually some coal which can be obtained with little or no stripping. As the work is carried down the pitch of the coal seam, the proportion of overburden continually increases until a point is reached where it is no longer economical to continue the operation. The question immediately arises as to the location of this point, and this resolves into the problem of determining the most favourable strip ratio, or, to use the accepted term, the economic ratio.

Jan 1, 1949