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By X. Xu, J. K. -W. Wong, J. -Y. Delenne, K. Soga

Hydraulic fracturing (HF) is a mulit-scale and multi-physics process which makes numerical modelling challenging. Conventional numerical models focus on multi-physics nature of HF but the multiscale nature is compromised by idealization of reservoir to be continuous, homogeneous and isotropic. However, natural fractures take a significant role in the success of HF for exploration of unconventional resources like Shale gas. Advancement in microseismic monitoring provides useful data for simulation in a much greater details. There is an urgent need to develop a suitable numerical tool for multi-scale threedimensional simulation to better understand the roles of discontinuities and heterogeneity in reservoir and its interaction with HF, especially to address the environmental concerns such as induced seismicity. In this paper, a simple discontinuum numerical method – Lattice Element Method (LEM) is proposed to model HF in a large scale three-dimensional model. A reservoir is modelled as a lattice network composed of 1D Hookean’s spring. Fracturing is modelled simply by removing lattices that meet a specified threshold as determined by the critical energy release rate of the rock. By introducing disorder in the model, mesh dependency in modelling fracture growth is minimized. Fluid flow is simplified as flow in pipe network and the permeability of pipe is related to fracture aperture by cubic flow law. Therefore, fracture flow and rock deformation are fully coupled. In this paper, four simulations of the same configuration except with different degrees of reservoir heterogeneity are presented. Fractures formed are diffusive and two groups of fracture are identified – connected fractures and isolated fracture without clear spatial correlation. The former forms a ‘fracture cloud’ and contributes to fluid flow and modeled by pipe network. The flow of fluid is highly tortuous and pipe network is sparely connected. The degree of reservoir heterogeneity controls the growth of ‘fracture cloud’ and pipe network. Microseismic monitoring often shows diffusive fracturing during HF on site and hence the outcome of the proposed model can be compared to such monitoring results.

Jan 1, 2015

By Alain Grenier

To be more competitive, we have to try new mining techniques. A few of them are: extend honghole length increase drilling precision new type of primary opening (slot) use of CMS to extend stope length This paper will cover our trials, successes and failures and will cover a few real cases that occurred at the Doyon mine.

Oct 1, 2001

By G. A. Gross

Nearly 90 per cent of the iron ore produced in Canada is derived from iron-formation or bedded iron deposits. About 70 per cent of this consists of concentrates obtained fom iron-formation; another 20 per cent was formed by natural enrichment processes. Four principal varieties of iron-formation are recognized -the Algoma, Superior, Clinton and Minette types. Differences in their geology, mineralogy, chemical composition and environment of deposition are of special significance in their evaluation as ore.

Feb 1, 1966

By J. M. Ortiz, J. P. Bertini

"In mineral resource and ore reserve estimation, several sources of information are generally available, such as diamond drillholes, reversed-circulation drillholes, and blastholes, and originate from one or more sampling campaigns and are analyzed by one or more laboratories. In such a situation, the grade measurements may not have the same precision and one should distinguish between hard and imprecise data.This work aims at studying the impact of data imprecision in resource/reserve evaluation through two case studies on simulated deposits: a porphyry copper deposit conditioned to real exploration and production data, and a gold deposit simulated without any conditioning data. Several geostatistical techniques are used to estimate the grades of selective mining units from exploration samples, including kriging, cokriging, lognormal and indicator kriging. Two types of imprecision are examined— measurements with multiplicative errors and measurements defined as intervals. The results are compared to the simulated grades of the selective mining units from a statistical and economic viewpoint.The study concludes that imprecise measurements should never be discarded because they help to improve the estimates, and that simple methods such as kriging are as efficient as more sophisticated ones for resource/reserve assessment. Finally, a few indications on how to diagnose and model the data imprecision are given."

Jan 1, 2005

By W. J. Bennett

"I AM very happy to have this opportunity of speaking to the Montreal Branch of the Canadian Institute of Mining and Metallurgy.I have selected as the subject of my remarks transportation in that area which is at present our only source of uranium -Northwest Canada. Considering the widespread interest in atomic energy, the end-product of uranium, it may be wondered why I have not chosen to speak of a more spectacular aspect of the development. I hope it will be evident from what I have to say that transportation plays a very dominant role in our effort to maintain a continuing supply from Eldorado's producing property at Port Radium on Great Bear lake and from its coming producer at Beaver lodge Lake in Northwest Saskatchewan. Moreover, transportation has such a bearing on the entire mineral development of the Northwest that it cannot help but be of concern to an organization of this kind. Finally, the transportation problem, of which I shall try to tell you something, is quite unique and the story of its solution or partial solution is, I believe, an interesting one.Transportation experience on this continent indicates that the cheapest method of moving freight is still by water -with •rail, highway, and air transportation following, and in that order •of economic significance. Excluding rail transportation, since the area has as yet no railway lines, this order also applies in the Northwest. I shall direct my remarks to the two kinds of transportation which serve our uranium producers -water and air."

Jan 1, 1952

By J. R. Kish, J. Dabrowski

"The susceptibility to intergranular corrosion modes is a major technical issue preventing widespread utilization of higher strength welded AA7xxx extruded beam profiles, in the peak-aged T6 condition, in automotive bumper assemblies. A study was undertaken to evaluate the relative exfoliation corrosion resistance (ASTM G85-A2) as a function of joint design parameters, namely the base alloy composition, heat-treated condition and beam orientation after exposure to a cyclic acidified salt spray test. This paper documents the major findings extracted from this study.INTRODUCTIONBumper systems play a predominant role in the passive safety of an automobile, since they are one of the main structures for absorbing the collision energy in the event of an automobile crash. Heattreatable AA6xxx-series (Al-Mg-Si) and AA7xxx-series (Al-Zn-Mg) Al alloys, with relatively high strength, toughness, energy absorption, weldability and formability, make it possible to design costcompetitive bumper systems to crush in a controlled fashion. In this context, Cu-lean AA7xxx extrusions, such as AA7003 and AA7108, which exhibit higher strength than AA6xxx extrusion, such as AA6082, represent an attractive light weight material from which to fabricate bumper assemblies (Clausen et al., 2000; Pedersen et al., 2008; Chen et al., 2009).Arc welding is a key joining process for AA7xxx alloys within the transportation industry. A major technological issue preventing widespread utilization of arc-welded AA7xxx joints is the susceptibility to severe localized corrosion (Kent, 1970, Reboul et al., 1985; Holroyd et al., 1987). It generally occurs as exfoliation corrosion within a heat affected zone (HAZ) a few millimeters from the weld bead, or a type of stress corrosion cracking (weld-toe cracking), which initiates at the weld toe and propagates into the interfacial region between the weld bead and the HAZ (so called “white zone”). In addition to the micro-galvanic cell activity induced by the intermetallic compound constituent and strengthening particles present, there is strong evidence that macro-galvanic cell activity between the weld bead and base AA7xxx alloy may be playing a controlling role. Electrochemical profiles taken across fusion welded joints, in cross-section, during exposure to saline solutions suggest that a significant potential difference exists across the AA7xxx arc-welded joint (Shumaker et al., 1967; Grauer and Wiedmer, 1980; Tuck, 1985, Onoro and Ranninger, 1993). These studies consistently show that the HAZ and base alloy are more electronegative with respect to the weld bead (arc-welded with AA5xxx filler wire). Despite this initial important work, the majority of the recent corrosion research effort on welded AA7xxx alloys has focused on the performance of friction stir welds (Lumsden et al., 1999; Wadeson et al., 2006; Hatamleh et al., 2009)."

Jan 1, 2012

By B. Arlyuk

On the basis of research of relations among the market participants the analytical model has been created which connects the price of industrial good at stock exchange with volume of sales and the stock of the sellers and buyers, Also a model was developed for assessment of these parameters of the market status by the actually fixed stock exchange and general market indicators. The composition of these models made it possible to create reliable system of short-term price forecasting for commodities or base metals up to one quarter ahead. Imperfectability of creation a model for reliable price forecasting by purely statistic methods (by the "black box" principle) was shown. A model of price behavior qualitative forecasting till one quarter ahead has been developed, which determines the probability of reaching in future of the given level as well as of the price maximums and minimums, Optimal values of threshold probability were determined for forecasting the future price maximums and minimums securing the maximum profit from the forecasting system application for commercial activity. The developed system of forecasting was identified for primary aluminium at the period of 1990-2003. The system was tested daily during 20 months period for speculations on 3M primary aluminium forwards at London Metal Exchange with high commercial result.

Jan 1, 2004

By J. Chretien

The ability to continuously monitor the air quality within a mine has become instrumental in becoming a low cost producer. The many considerations involved in monitoring air quality include sensor type, hardware placement, as well as data storage medium. BESTECH has had the opportunity to gain insight into these air quality monitoring considerations through deployments of NRG1-ECOTM, a minewide energy consumption optimization system. This paper explores the particular challenges overcome through these installations, and provides a set of guidelines for mines that want to maximize data capture while minimizing costs. It provides a view of additional benefits of air quality monitoring, such as ventilation control, reporting and trending.

Aug 1, 2013

By Y. Buro

The Bachelor Lake gold deposit occupies an ESE-trending, SW-dipping, silicified shear zone with hematitic alteration. It transects NE-trending, steeply dipping Archean volcanic formations and the O'Brien granite. Major W-SW and N- NE-trending faults have affected the ore zone and the emplacement of the granite intrusions. Movements along the WSW set may have opened the fractures filled by the mineralization. Gold is generally associated with pyrite. Its source, whether a granitic pluton or a volcanic sequence, is undetermined, but the granite probably provided the concentrating mechanisms through heat and hydrothermal solutions.

Jan 1, 1984

By D. W. Heard

Electrospark Deposition (ESD) is a low heat-input, high energy density, micro-welding process. The short pulse duration and high-pulse frequency, in combination with the small amount of material transferred during each pulse, results in the evolution of extremely rapid cooling rates, believed to approach 105-106 °C/s [1]. This rapid solidification event results in the refinement of the microstructure to the nanostructured or amorphous level [2, 3]. Figure 1 displays the resultant microstructure of an Al-17%Si alloy deposited by the ESD process. Furthermore, it was determined that the microstructure of the deposit remained unchanged after subsequent layers were welded onto the presented layer. Freeforming of materials is a rapid prototyping process in which the deposited feedstock is built-up to the desired geometry in a near-net shape manner. Figure 2 displays the automated set-up employed produce three dimensional freeformed objects via multiple deposition trials of the ESD process. The automated XYZ table is equipped with CNC software to transform CAD renderings into three dimensional tool paths. Figure 3 displays an Al-12Si freeformed gear (2" diameter, 12 teeth) produced by the ESD process, prior to removal from the substrate. An SEM analysis of the freeformed component showed that the microstructure did not coarsen during the deposition of subsequent layers during the freeforming process, as depicted in Figure 4, resulting in the production of a bulk nanostructured component. This paper represents a summary of the capabilities of ESD to fabricate advanced materials possessing refined microstructure. In particular, results on the microstructural evolution obtainable for various wear-related systems will be presented. In addition, the feasibility of using the ESD process to freeform three-dimensional objects via multiple deposition passes will be presented and accompanied by a characterization of the properties of the freeformed component. [1] R. N. Johnson, "ElectroSpark Deposition: Principles and Applications," in Society of Vacuum Coaters, 2002, pp. 87-92. [2] J. Milligan, D. W. Heard, and M. Brochu, "Formation of nanostructured weldments in the Al-Si system using electrospark welding," Applied Surface Science, vol. 256, pp. 4009-4016. [3] S. Cadney and M. Brochu, "Formation of amorphous Zr41.2Ti13.8NilOCul2.5Be22.5 coatings via the ElectroSpark Deposition process," Intermetallics, vol. 16, pp. 518-523, 2008.

Jan 1, 2010

By P. R. A. Andrews

"Talc ore from Bakertalc, High water, Quebec analyzing about 60% talc, previously dry ground to about 95% minus 53 µm was beneficiated in an 11.4 kg/ h pilot-plant flotation circuit. A concentrate of 95.9% talc (necessary for paper-grade) was obtained at a recovery at 75.3% by employing 53 g/t of Dowfroth 250 collector at pH 9.2; further cleaning increased the grade to 97.2% talc at a recovery of 57.5%.Flotation of fresh ground 60% minus 44 µm ore at a feed rate of 18.6 kg/ h produced a grade of 96.4% talc with a recovery of 78.2%, using Aerofroth 70 collector a six carbon-branch chain alcohol, at pH 9.2.The similarity in the concentrate grade and recovery between pre-ground and fresh-ground ore indicated that it was not neces¬sary to grind to 95% minus 53/2m to achieve comparable selectivity. A grind of 60% minus 44 pm corresponds to 100% minus 300 µm.Flotation retention times obtained with fresh ground ore indicate 33 min. for combined rougher/scavenger, and 15 min. each for the first and second cleaners.Talc-magnesite flotation separation is explained in terms of physico-chemical forces, with reference to surface charge and adsorption mechanisms."

Jan 1, 1989

By John Hansen

This paper has been written for presentation at the 103rd Annual General Meeting of the Canadian Institute of Mining, Metallurgy, and Petroleum, April 29 to May 02, 2000. The paper addresses blast pattern fragmentation and diggability versus the blasting technique used. RESUME The author is the Vice President for Thunderbird Mining Systems. In this capacity he manages the mine site installation of surface mining mobile equipment monitoring and navigation systems. These systems are onboard instrumentation and software systems designed to: ??measure and log mobile equipments? production and health; and ??direct the equipment operators via onboard displays that show comprehensive maps and engineering instructions. The author is a mining engineering graduate from the Royal School of Mines. His work experience includes front line supervisor and mining engineer for Hudson Bay Mining & Smelting, mining engineer for Teck Corporation, and mining consultant for PriceWaterhouseCoopers.

May 1, 2001

By R. M. Oliver

THE Falconbridge property is almost completely covered with over-burden to a depth varying from 60 to over 200 feet. This overburden consists of grave], sand, and boulder, with bands of very fine silt, and there is usually a layer of water-bearing quicksand adjoining the r:ock surface. In previous shafts sunk at Falconbridge, this water-bearing quicksand had given considerable trouble, and further difficulties were expected in sinking No. 5 shaft, due to its greater size. The method described in this paper is the one adopted in sinking this shaft, after the matter had been carefully considered. No. 5 shaft is located 2,400 feet east of the old main No. l shaft, and is sunk in norite in the hanging-wall of the ore-body, which is, however, ? practically vertical to the deepest known intersection. The greatest depths of overburden prevail on the south side, or footwall, of the ore-body, and this, together.. with the fact that the footwall is wet and more badly fractured, swayed the final decision to sink in the hanging-wall. After the shaft site had been chosen and cleared, a diamond drill was set up a few feet away and a hole bored to a depth of 405 feet to test the over-burden and character of the norite bedrock. The depth of overbudren indicated by the hole was Ill feet, with the last 10 feet water-bearing. The norite was rusted and broken up for only a few feet below bedrock. A steel sinking shield (Figure l) was assembled at the shaft location, and consisted of 5/8-inch plate, 5 feet deep, built around a frame of 6 inch by 6 inch angle-iron, and braced at the corners with the same material. Twelve-inch I-beams held the shield as rigid as possible. In order to reduce binding against pebbles to a minimum, the shield was constructed with a 1-inch batter on all sides.

Jan 1, 1938

By V. Loya

Metallic foams (MF) are relatively new materials with a combination of attractive properties (permeability, high surface area, thermal and chemical stability, etc,), They can be produced from different materials and can be manufactured using various processes, Due to their unique properties, they find applications in different sectors of engineering, such as energy absorption, filtration, heat dissipation, etc, For many applications, the permeability is an important parameter to characterize and optimize, Most of the recent literature on the subject studied the permeability in the low velocity range. The present study was carried out to have a better understanding of permeability for greater velocity ranges, An equipment was designed and built for this purpose, Pressure drop measurements were made across the thickness of open-cell nickel foams, Pore and window sizes were measured by image analysis on SEM micrographs, The experimental results are in relatively good agreement with the Hazen-Dupuit-Darcy model (R2>98%), The permeability is affected by pore size, porosity and the normalized projected area of the connecting pores (ie. windows).

Jan 1, 2005

By C. Carrasco

Caletones Smelter, Division El Teniente of Codelco Chile, has used Teniente Converter (TC) as the only smelting unit since November 2000. The modernization project considered the shutdown of the last reverberatory furnace, the installation of the fourth Teniente Slag Cleaning Furnace, the installation of a new fluidized bed dryer and the modification of the concentrate injection system into TC. The modernization project and related investments allowed for the increase of the smelting capacity up to 1.25 million t of concentrate annually.Next stage of the smelter expansion in the year 2004 considered the increase of the smelting capacity up to 1.44 million t/year. The expansion required technology modernization and the installation of the new equipment, such as concentrate injection system, oxygen plant, fluidized bed dryer and storage bin. Currently the annual smelting capacity is about 1.35 million t of copper concentrate, being limited by sulphuric acid plant treatment capacity. This paper presents the technology and production evolution in the Caletones Smelter in the years 2000 - 2006, demonstrating the potential of development and competitiveness of Teniente Converter as world-wide recognized smelting/converting reactor.

Jan 1, 2007

By Chuan-liu Wang

The bionic non-smooth surface has the characteristics of anti-wear, and reducing resistance. Based on bionic non-smooth surface?s characteristics, a bionic drill bit was developed. When the bionic drill bit is used, a bionic non-smooth surface forms on the crown of bionic drill bit. This surface can be used to extend the life of drill bit and improve drill efficiency. The bionic unit diameter and arrangement were researched in this paper to determine the optimal bionic non-smooth surface for further improving the life and efficiency of drill bit. Four bionic samples having the same structure size, materials and arrangement were designed and manufactured. After being sintered, the abrasion ratios of the four bionic samples were tested, and the results show that the abrasion ratio of Nos. 3 and 2 were similar (only 2% difference) and higher than that of No. 1 and 4. Therefore, the optimal diameter of bionic unit is 1.5 and 2.0 mm. Small diameter bionic drill bits were designed and manufactured, and tested in the laboratory. The results show that not all bionic structure bodies are better than normal diamond bits, except the bionic unit arranged in a reasonable range. When the angle was 24° and 30°, the arrangement of bionic unit were more reasonable, which shows the superiority of the bionic coupling bit.

Aug 1, 2013

By John D. Galloway

Mining is one of the important primary industries of Canada, with a gross production in 1927 estimated at $241,773,000- the highest in the history of the country-and an impressive dividend record. It is quite apparent, therefore, that mining is a business worthy of the careful attention of the people of Canada. Furthermore, with a vast undeveloped territory more or less mineralized, it is highly probable that our mining industry will continue to expand indefinitely, with a consequent increase in production and in the amounts of the yearly profits distributed. In recent years, the public has taken a larger interest than formerly in mining-an interest, moreover, that is not academic, but primarily from the viewpoint of profits. It is quite evident that mining is a profitable business, at least to some, and the average man on the street, hearing of these profits, is attracted thereto. I have no doubt that many of you have .read in promotion prospectuses, with figures to prove it, that mining is the most conservative, the safest, and the highest-yielding business in the world. Now, a lot of this information is best judged by the old saying that "While figures don't lie, liars figure". At the same time, mining, properly conducted, is a profitable business, even though speculative, and undoubtedly much profit will come from Canadian mines in the future. In this paper my conclusions regarding mining investments are based largely on British Columbia experience, together with some slight knowledge of mining conditions in the other Provinces. It is considered, however, that the inferences drawn are applicable to mining throughout Canada.

Jan 1, 1928

By W. L. Goodwin

Twenty-five years ago mining engineering in Canada was not a profession. To-day the members of the mining fraternity can fairly claim for 10themselves the professional status. If their pretension is not fully warranted by fact it is not for lack of any technical attainment or service to the public but by reason merely of their neglect to cultivate the cohesion and consciousness that are the outward and visible signs of a professional body. This paper is an attempt, first to sketch briefly the course of the events during the past thirty-five years that have resulted in organizing the mining industry of this country in its present form; then to notice the principal features of the professional organization of this day; and finally to point out that an important part of the work of the mining engineer remains in the state of chaos that characterized the whole of it three or four decades ago, and to suggest a remedy. Thirty years ago there came a great wave of interest in mining in Canada, based principally upon the discovery of gold-quartz and gold-copper throughout wide areas in Nova Scotia, Ontario and British Columbia.

Jan 1, 1926

By Zhan Zhang, Hiromi Nagaumi, Zhen Li

"Recently, the remarkable strengthening effect of ??-Al(Mn, Fe) Si dispersoids at both ambient temperature and elevated temperature were found by several researches. A large amount of dispersoids can be formed by applying special heat treatments and within a suitable range of chemical composition of AA3xxx alloys. In the present work, the influences of Cr addition on the mechanical properties and microstructures of the Al-Mn-Mg-Si alloys were investigated. The mechanical properties at ambient and elevated temperatures were evaluated by micro-hardness and yield strength. Moreover, the microstructures in as-cast and heat-treated conditions were quantitatively analyzed by optical and electron microscopes. Results revealed that Cr also had effect on the number density and volume fraction of dispersoids. Micro-hardness and yield strength at ambient temperature increased with the increasing content of Cr, and the Cr addition increased the yield strength at elevated temperature as well. Moreover, the creep resistance at 300°C improved dramatically with the increasing content of Cr.INTRODUCTION Traditionally, AA3xxx aluminum alloys were widely used in packaging, automobile and architecture industries, because of its good formability, excellent corrosion resistance and weldability. And AA3xxx alloys were considered as non-heat-treatable alloys. However, the strengthening effect of dispersoids in AA3xxx alloys was discovered recently (Li & Arnberg, 2003;Li, Muggerud, Olsen, & Furu, 2012; Li, Zhang, & Chen, 2016; Liu & Chen, 2015).Alarge amount of dispersoids could precipitate by a proper heat treatment.In order to further improve AA3xxxalloys, the composition of the alloys should be optimized. A few previous studies were reported to investigate the influence of compositions on AA3xxx alloys. Adding Mn element could enhance the precipitation of ??-Al(Mn, Fe)Si dispersoids and improve the yield strength(Muggerud, Mørtsell, Li, & Holmestad, 2013), as long as the concentration of Mn was under the solid solution limit. Fe decreased the solubility of Mn and accelerated the precipitation rate of ??-Al(Mn, Fe)Sidispersoids(Li & Arnberg, 2003), the yield strength and creep resistance at elevated temperature could increase with an optimized content of Fe(Liu & Chen, 2016). Mg element would affect the nucleation process of ??-Al(Mn, Fe)Sidispersoids by forming metastable Mg2Si(Hirasawa, 1975; Li, Zhang, & Chen, 2017a; Lodgaard & Ryum, 2000), metastable Mg2Si precipitated during heating process and promoted the precipitation of ??-Al(Mn, Fe)Sidispersoids, moreover, Mg provided solid solution strength for AA3004 alloys(Li et al., 2016). Si increased the volume fractionof ??-Al(Mn, Fe)Sidispersoids(Muggerud et al., 2013)and decreased the size of ??-Al(Mn, Fe)Sidispersoids(Li, Zhang, & Chen, 2017b). With the addition of Mo, the size of dispersoids became finer with a higher volume fraction, the volume percentage of dispersoid free zones was reduced. Elevated temperature yield strength and creep resistance improved due to Mo addition (Liu, Ma, & Chen, 2017).However, the effect of Crelements on microstructure and mechanical properties of AA3xxx alloys were rarely reported."

Jan 1, 2018

By Diego L. Romero, Joy P. Romero

"IntroductionThe purpose of this paper is to explain the theory and demonstrate the industrial applications of electrostatic separation. Wabush Mines' use of this type of processing for the concentration of iron ore is unique in the industry. Other minerals are concentrated electrostatically but the process is not widely used.Typical minerals separated by electrostatic separation techniques are:Non-ConductorsAnhydriteApatiteBariteBastnasiteBerylCalciteChrysotileCorundumDiamondEpidoteFeldsparsFluoriteGarnetGypsumHornblendeKyaniteAcmiteAugiteBrookiteCassiteriteChalcopyriteChromiteColumbiteCopperDaviditeEuxeniteFerberiteFrankliniteGalenaGoldGraphiteHematiteMica (Biotite)Mica (Muscovite)MonaziteOlivinePerovskiteQuartzScheeliteSideriteSillimaniteSpheneStauroliteSulphurTopazTourmalineXenotimeZirconConductorsIlmeniteIlmenite-( High Iron)IlvaiteKoppiteMagnetiteMarmatiteMolybdenitePyriteRutileSamarskiteSphaleriteTantaliteWolframiteWulfeniteThe limitations of this process are:1. There must be a difference in conductivity between the minerals being separated.2. The size range must not be very wide.3. The specific gravity of minerals being separated should be similar or the minerals to be pinned should be lighter. 4. The feed must be dry.5. The particle shape should be more or less uniform. 6. The feed must not be high in true middling particles."

Jan 1, 1989