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By Stéphane Robert

This document presents estimates of future "total cash cost per ounce" and "minesite cost per tonne" that are not recognized measures under United States generally accepted accounting principles ("US GAAP"). This data may not be comparable to data presented by other gold producers. These future estimates are based upon the total cash costs per ounce and minesite costs per tonne that the Company expects to incur to mine gold at the applicable projects and do not include production costs attributable to accretion expense and other asset retirement costs, which will vary over time as each project is developed and mined. It is therefore not practicable to reconcile these forward-looking non-GAAP financial measures to the most comparable GAAP measure. A reconciliation of the Company's total cash cost per ounce and minesite cost per tonne to the most comparable financial measures calculated and presented in accordance with US GAAP for the Company's historical results of operations is set forth in the notes to the financial statements included in the Company's Annual Information Form and Annual Report on Form 20-F, for the year ended December 31, 2009, as well as the Company's other filings with the Canadian Securities Administrators and the SEC.

May 1, 2011

By D. Sancho, M. Weber

"At the start of a new shaft project, a specific number of ground investigations are performed. However, it is not uncommon that the ground conditions during shaft sinking may differ from the designed ones. Therefore, it is extremely important to use tools which minimize discrepancies and to include a monitoring system in the shaft design to collect sufficient data. The paper presents an overview of existing monitoring techniques and discusses future works required to improve, not only the construction during shaft sinking, but also the lining design methodology. INTRODUCTION In most cases, the investigations performed at the start of a new shaft are based on the analysis of rock and soil probes obtained from boreholes. In practice, such analysis performed on a single core often leads to different results when conducted by various experts. The discrepancy in core analysis influences further rock mass assessment and design assumptions. It is not uncommon that the ground conditions during shaft sinking may differ from the designed ones, which affects the estimated stress and strain state of the shaft lining. Therefore, it is extremely important to use tools which minimize such discrepancy and to include into the shaft design a monitoring system to collect sufficient data, which enables control of important phenomena, not only during shaft sinking but also during the life of the shaft. Furthermore, the information collected during shaft sinking, while it is important for proper shaft lining design and updates to the shaft lining due to the local mining and geological conditions, it is also important after shaft sinking. In the whole shaft lifetime, it is not uncommon that the shaft lining is damaged and the liner needs to be renewed (Figure 1) due to various reasons. For this purpose, detailed information collected during construction can be extremely important."

Jan 1, 2019

By C. Liu

Zeta potentials and settling rates of an oil sands tailings sample taken from Syncrude Canada Ltd's Aurora Stacker Pilot Operation were studied. Two clay minerals, kaolinite and illite, were also studied since these are the major constituent minerals in the fine oil sands tailings. Process water, decanted water as well as distilled water were used. It was observed that the zeta potentials of the tailings solids showed maximum negative values in process water at pH 8-10, which coincides with the pH of commercial hot water bitumen extraction process. The settling rates of the tailings sample were very low, at 0.008 m/hr in decanted water and 0.04 m/hr in process water. The rates were increased to 1.0 m/hr in decanted water and 0.13 m/hr in process water at an addition of 50 g/t Ciba AF1235. Although the settling rate was higher the supernatant was cloudier in decanted water than in process water. Further increase in the dosages of Ciba AF1235 did not increase the settling rates in decanted water but gradually increased it in process water, reaching 0.46 m/hr at 100 g/t. The results indicated that lower concentrations of Ca2+ and Mg2 (in decanted water) benefited settling rates but did not benefit supernatant clarity. Test results also indicated that Ciba AF1235 caused selective flocculation of the tailings sample, since the top sediments had higher illite and lower quartz contents than the bottom sediments.

Jan 1, 2006

By N. Bahrani

Photogrammetry surveys were used to document a footwall slab failure that occurred at a surface coal mine located on the eastern slope of the Rocky Mountains. Photographs taken before and after the failure provided the pre- and post-failure geometry of the slope and the failed slab. A 2D finite element model was constructed using slope profiles. The model contained joint elements that represented the bedding surface upon which the slab slid and the model was used to analyze the footwall slope. The in situ stresses, rock properties and the bedding surface shear strength and stiffness properties are discussed. The process of mining out a valley and exposing a highwall was modelled. As expected, elastic valley rebound occurred in the model, but shear stress and shear displacement reversals along the slip surface were also observed. The modelling results provided new insight into shear strength degradation that occurs when the pit floor approaches and then passes a specific point in the highwall.

Jan 1, 2009

By M. J. Davie, D. S. Ross

"The successful design of a new mine water pumping system is in part dependent upon the accuracy with which the operating conditions can be forecast. This paper outlines the data which should be obtained on water quantity and quality. Methods of modifying the quality are also discussed. Some pumping systems for disposal of sludge are described, citing operating examples. The various types of mine dewatering pumps are described in terms of design characteristics as they affect operating efficiency and installation and maintenance costs. Piping system parameters are outlined. Finally, a hypothetical case study of pumping from a depth of 3,000 ft is assessed, with particular reference to capital costs.IntroductionMany mine operators would agree that the pumping system usually receives a low engineering priority during the design stage, and as a consequence causes some of the most frustrating problems during production. For a ""dry"" mine (up to 200 gpm), design of the pumping system may indeed be simple, but outside of the potash industry such mines are not common. For ""wet"" mines, the pumping system is important because it significantly affects the initial capital and on-going energy costs of the mine and, in the area of sludge disposal, the working conditions and production costs. Indeed, a failure in the pumping system usually has serious, and sometimes disastrous, consequences.The intent of this paper is to outline the factors which should be considered in the design of a pumping system and to describe the types of pumps used in mine dewatering and relate them to practical operating systems."

Jan 1, 1980

By R. J. Smyth

A Steel Compression Reinforcement Repair Technique (PetroSleevel) system has been developed that has the ability to repair pipeline defects such as stress corrosion cracking (SCC) without requiring welding to the operating pipeline. The Technology has been used to repair active cracking in ERW seam and cracking in the pipe body. All repairs were performed while the pipeline was in operation. This paper will discuss the engineering theory, testing performed to verify the engineering theory, and examples of actual sleeve installations.

Jan 1, 2005

By W. D. Sinclair, R. J. Cathro, E. M. Jensen

"The Cash is one of the largest porphyry copper-molybdenum Deposits found in Yukon to date. It is 80 km northwest of Carmacks, within the unglaciated portion of the Dawson Range, and is associated with the Big Creek fault, an important tectonic feature. Part of the mineralized zone is blanketed by up to 70 m of alluvial drift . The remainder is covered by a relatively thin residual soil layer. The mineralized zone, however, was not detected by conventional stream-sediment sampling because pathfinder elements, such as Cu and Mo, have not been geochemically dispersed into the main drainage system. The deposit was discovered by a combination of soil analysis and inspection of rock fragments from small pits.Twenty widely spaced, shallow drill holes have outlined an areaover 2700 m long and 550 to over 1000m wide that grades more than 0.1% copper equivalent (% CuE = % Cu + (5 x % MoS2)). Two smaller zones grading over 0.4% copper equivalent occur within the larger area. The limits of the widest end of the deposit have not been delineated.The Cash deposit is fairly typical of high-level, calc-alkaline porphyry copper-molydenum occurrrences in the Canadian Cordillera {cf, CIM Special Volume 15) and is representative of most prospects in the Dawson Range. It is associated genetically with a subvolcanic complex of small, irregular stocks and dykes of feldspar porphyry and related breccias of Late Cretaceous age. Copper and molybdenum sulphides occur along fractures, in quartz veinlets and disseminated in feldspar porphyry and in older metasedimentary and intrusive rocks. Higher-grade zones of copper and molybdenum have associated potassic alteration. Phyllic alteration is, in part, superimposed on potassic alteration. Argillic alteration occurs locally.This paper describes the history of the discovery and the geochemical and geophysical characteristics, together .with the regional geology, and the nature and distribution of the host rocks, hypogene mineralization and hydrothermal alteration."

Jan 1, 1981

By D. Komljenovic, E. Lafontaine, J. Paraszczak

Availability of the production equipment used in underground mines has a substantial impact on production costs and, thus, on mine profitability. Appropriate collection of pertinent data and information, as well as use of adequate performance measures and their analyses, can help mine operators identify cost-effective opportunities to improve equipment availability. This paper presents study results aimed at reviewing and analyzing means and measures used to quantify equipment availability and its contributing factors (reliability, maintainability and maintenance support) in several Canadian underground mines. It overviews sources, as well as quality and quantity of relevant data and information, and examines performance measures and their definitions, as applied to surveyed mines. Problems concerning data acquisition and meaningfulness of the performance measures are discussed. The paper concludes with some suggestions and recommendations concerning several aspects of equipment availability assessment. Evidence suggests that the latter may become a more useful tool for mine operators in their efforts to reduce production cost.

Jan 1, 2008

By X. -G. Chen, K. Liu, N. Parson

"Precipitation-strengthening 6xxx alloys are widely used for building and construction and automobile industries due to their high strength, good weldability and corrosion resistance. However, their elevated-temperature properties (250–300°C) decrease rapidly due to the fast-coarsening of precipitates. On the other hand, dispersoid-hardening is one of the most efficient approaches to improve the elevated-temperature properties. Therefore, the evolution of dispersoids during heat treatment in Al-Mg-Si-Mn alloys was investigated in the present work. Various heat treatments with temperatures ranging from 300–500°Cfor up to 24 hours were performed. Electrical conductivity and microhardness were measured while optical and scanning electron microscopy combined with image analysis, were used to characterize the dispersoids. Special emphasis was placed on the evolution of the size and number density of the dispersoids under different heat treatment parameters. It was found that dispersoids started to precipitate at 350°Cfor 1 hour. Nucleation and growth were the main mechanisms at temperatures up to 400°Cwhile coarsening occurred at temperatures above 450°C. The quantitative results indicated that dispersoids precipitation reached the optimum condition after treatment at 400°Cfor 2–4 hours with a fine size and high number density, resulting in the highest hardness.INTRODUCTIONThe precipitation-hardening 6xxx aluminum alloys with major alloying elements of Mg and Si are one of the most widely used aluminum alloys for building and construction and automobile industries (Dinaharan & Murugan, 2012). In recent years, there have been increasing demands for aluminum structural components to be used at elevated temperatures (250–300°C) for different applications. However, the mechanical properties of 6xxx alloys at elevated temperature are typically reduced due to the rapid coarsening of precipitates at 250–300°C. It has been reported that the yield strength (YS) of AA6061 in the peak-aged condition drops from 276 MPa at room temperature to only 30 MPa at 315°C(Kaufman, 1999). Therefore, it is a key concern to improve the elevated-temperature properties of 6xxx alloys to expand their range of applications."

Jan 1, 2018

By Jack Young

U. S. Steel Canada Inc.’s Lake Erie Works is the last green field integrated plant to be built in North America. The plant was designed using the best available environmental technology to develop an environmentally friendly production facility. A summary of the technology and measures used in the construction of the plant are summarized in this paper.

Jan 1, 2015

By D. Song

In this paper, the differential equations governing the mass transport and the electrochemical reaction in a cathode catalyst layer of polymer electrolyte membrane fuel cells are solved based on the polynomial series expansion method. Explicit expressions for the polarization curve as well as for the distributions of oxygen, current density and overpotential are obtained when a quadratic, cubic or quartic polynomial is employed to approximate the oxygen concentration distribution. These kinds of explicit solutions are desirable for MEA design and diagnosis purposes. The comparison between the conventional numerical approach and the explicit solution approach proposed here shows that satisfactory accuracy can be reached by the first four terms of the polynomial series. The effect of the catalyst layer thickness on the accuracy of the obtained explicit polynomial solutions is also discussed.

Jan 1, 2005

By K. van Warmerdam, M. Pearson, C. Kember, D. McMullen, M. Thayer, C. Ugarenko

In July 2012, Hatch Ltd. and Air Products & Chemicals Inc. completed construction and commissioning of a 4000 tpd O2 cryogenic air separation unit (ASU) for Barrick Gold’s Pueblo Viejo Project located in central Dominican Republic. The ASU produces high pressure gaseous oxygen, which is used for the oxidation of refractory sulphide ore within the pressure oxidation (POX) circuit. As a result of the project’s remote location and tropical climate, many challenges were faced over the course of construction, commissioning and start-up of the ASU. These challenges included adequate preservation of equipment due to dusty and humid site conditions, final assembly and erection of the cryogenic distillation columns on site, limited spare parts inventory/availability, and an unfinished power source for plant commissioning. This paper discusses the steps taken by Hatch and Air Products to successfully design, construct, commission and start up the largest stand-alone ASU plant for a POX application in the metallurgical industry.

Jan 1, 2014

By Tai Sik Lee

Why ISRU into Space Exploration are important NASA and International Mission statements calls for the sustainable human exploration of the Moon, Near-Earth asteroids, and Mars Common Exploration Goals and Objectives are Strongly influenced by ISRU Extend Human Presence: Continually increase the duration and level of self sufficiency at all destinations Develop Exploration Technologies and Capabilities: Develop and validate tools, technologies, and systems that extract, process, and utilize resource to enable exploration missions Perform Science to Support Human Exploration: Characterize available resources at destinations Stimulate Economic Expansion: Encourage commercial services and create new markets, including markets for discovered resources Enhance Earth Safety: Test techniques to mitigate the risk of asteroid collisions with Earth

May 1, 2013

By M. Kumral, E. Dilhuydy, B. Ozdemir

"In-pit crushing and conveyor (IPCC) systems have become increasingly popular in the mining industry as an alternative to truck-and-shovel systems. Deciding whether to haul waste rock by truck or IPCC represents an important gap to be investigated in semi-mobile IPCC systems. A cost analysis is presented to evaluate the feasibility of crushing and conveying waste material in IPCC systems, along with sensitivity and risk assessments through Monte Carlo simulation. Although the capital expenditure is higher, results showed waste crushing will be feasible in deep pits and over long mine life and haul distances.RÉSUMÉ La popularité des systèmes de concassage et de transport dans la fosse minière (IPCC, de l’anglais In-pit crushing and conveyor) n’a cessé de croître dans l’industrie minière ; ils constituent en effet une option intéressante de remplacement des systèmes par camions et pelles mécaniques. Le choix entre le transport des stériles par camions ou par IPCC est encore difficile à faire et devra faire l’objet d’une étude approfondie au niveau des systèmes d’IPCC semi-mobiles. Une analyse des coûts est présentée pour évaluer la faisabilité du concassage et du transport des stériles par les systèmes d’IPCC, de même que des évaluations de la sensibilité et des risques par le biais de la simulation de Monte Carlo. Si les dépenses en immobilisations s’avèrent être plus élevées, les résultats ont cependant montré que le concassage des stériles sera envisageable dans des fosses profondes ainsi que sur une longue durée de vie et de longues distances de transport. INTRODUCTIONThe mining industry is currently facing many challenges such as low commodity prices, increasing environmental concerns and regulations, lower grades, deeper mines, and greater waste-rock quantities. As a result, the profitability of mining operations has decreased, with many mines stopping or suspending operations, and many new projects being postponed. Mining companies have therefore focused on improvements and innovations to increase the cost effectiveness of operations, for example, increasing production capacity to take advantage of the economies of scale (Crowson, 2003) and decreasing the unit operation cost. Changes in production capacity force mining companies to evaluate alternative material handling systems.During the past few decades and within material handling systems, significant improvements have been made to truck performance and capacity. Consequently, operating expenditures (OPEX) associated with fuel and maintenance have risen swiftly. In a mining operation, truck hauling systems now represent 40–50% of the capital cost and approximately 45% of the OPEX (Tutton & Streck, 2009). Additionally, material transportation costs are expected to increase due to longer haul distances arising from deeper and larger mines (Fleet et al., 2015). Finally, large fluctuations in fuel prices result in high risks associated with truck OPEX. According to the United States Energy Information Administration (2015), the cost of crude oil—the largest component of the retail price of diesel fuel—increased from US$24.31/barrel in 1986 to US$46.92/barrel in 2016, peaking at US$151.72/barrel in 2008 (Macrotrends, 2016)."

Jan 1, 2017

By N. Morrison, I. Holl, R. Welyhorsky, A. Hempstock

ABSTRACT: The Victor diamond mine is located in the James Bay lowlands, 90 km west of the First Nations village of Attawapiskat. The project was the first of its kind in northern Ontario. The process plant was designed to produce a 95 to 98% by weight diamond concentrate through three stages of comminution, dense medium separation, and proprietary X-ray technology for final recovery. The plant was commissioned over a period of six months, commencing prior to substantial completion of construction. Through effective planning of the commissioning phase, the Victor mine start-up was safely completed nine months ahead of schedule.

Jan 1, 2011

By L. D. Snyder, J. K. Russell

"The Lower Jurassic Iron Mask batholith intrudes Upper Triassic Nicola Group volcanic rocks in the Quesnellia terrane of southcentral British Columbia and hosts Cu-Au mineralization. The batholith comprises three mappable intrusive phases, including: Pothook gabbro to diorite, Cherry Creek monzodiorite to monzonite and Sugarloaf diorite. The Iron Mask hybrid forms a fourth mappable unit that makes up to 45% of the areal exposure in the batholith. It is highly variable in texture and composition and subdivided into three types; Type I and II have abundant (partially digested) xenoliths, many of which are derived from the Nicola Group, whereas Type III is xenolith-poor and shows extreme outcrop-scale textural diversity.Pothook and Cherry Creek rocks are similar in texture, mineralogy, whole rock and mineral composition and style of alteration. Contacts between the two can be intrusive or gradational. Rocks collected from these two suites have compositions that are permissive of a single magma batch, although simple crystal fractionation does not explain all chemical variations within and between the two suites. The Sugarloaf unit comprises a diverse group of amphibole-phyric rock types and is texturally and mineralogically distinct from Pothook and Cherry Creek suites.The Iron Mask hybrid represents progressive stages of physical and chemical interaction between Nicola Group country rocks and Pothook magma. Magmatic assimilation (selective or partial) is supparted on the basis of field relationships, petrographic observations, and REB compositional data. Thermal dehydration and partial assimilation of Nicola Group rocks by Pothook magma is shown to be a valid means of promoting early and extensive volatile saturation in the Iron Mask batholith."

Jan 1, 1995

By Marvin J. Udy

THE preparation of this paper is in response to many requests for in-formation on the mining and smelting developments which have been carried on for the past three years or more by the Chromium Mining and Smelting Corporation of Canada. By way of introduction, the following paragraphs, relating to the early history and present status of the chrome-mining industry in the United States, are of interest. They are quoted from Bulletin No. 76 of the California State Mining Bureau, published in August, 1918: 'Chromium was discovered about 1797 by a French chemist, Louis Nicolaus Vauquelin, in ore from Siberia. From that time until 1827, the Urals, in the region of Ekaterinburg, supplied the chromium used in . Europe. In the summer of 1827, as the historian advises us, Isaac Tyson, Jr., saw in a Baltimore market-place a cart containing a cider barrel, which was held from rolling about by some heavy black stones. He had made a study of such stones at the first-known American locality, the Bare hills near his father's home, six miles from Baltimore, and he recognized the black stones as chromite. On inquiry, he found the chromite came from the Reed farm in Harford county, 27 miles northeast of Baltimore. At this time, Tyson was one of the very few men in the country who knew the value of chromite, and in the next few years he took full advantage of this knowledge. He immediately bought the Reed farm. He found about 30 tons of float-ore on the surface, but there was no outcrop of ore in place. Never-theless, he sank a shaft, and at a depth of eight feet struck an ore-pocket which proved to be 80 ft. long, 25 ft. wide, and 8 ft. in maximum thickness. His next discovery was of placer chromite in the sands in the beds of brooks on an estate called Soldiers' Delight, 16 miles northwest of Baltimore. Thus far, Tyson's observations had shown him that chromite occurred apparently only in serpentine areas. His explorations were now leading him farther afield. In 1828, he found on the Wood Farm, in Lancaster county, Pennsylvania, a deposit of float chromite which led him to lease the ore-right of the farm, which he finally purChased in 1832. Here he developed the famous Wood mine, the largest single producer of chromite in the world.

Jan 1, 1938

By Z. Yang, M. J. Collins, N. E. Tuffrey, R. J. Kalanchey, I. M. Masters

The high elevation of China Western Mining Company (WMC)' s Ganhe refinery, and the high iron content of concentrates produced by the WMC mines, were key factors in the selection of pressure leaching by WMC for their new zinc refinery. This paper describes the results of pressure leaching test work conducted by Sherritt in Fort Saskatchewan with a sample of WMC concentrate from Qinghai Province in China. Results from batch pressure leach tests and a four-day pilot plant campaign are reported. The pilot plant campaign included continuous operation of a two-stage pressure leach circuit, as well as neutralization and iron removal steps, resulting in the production of iron-free zinc sulphate solution. Greater than 98% zinc extraction was achieved in pressure leaching, while producing solution containing about 9 g/L H2SO4 and 2 g/L Fe. Following neutralization and iron removal, the solution contained about 170 g/L Zn and less than 10 mg/L Fe. Overall recovery of sulphur in the zinc concentrate feed to elemental sulphur byproduct was about 85%, while 75 to 80% of the indium in the feed was recoverable from the neutralization residue. The test results highlighted the technical and economic advantages offered by the Sherritt Zinc Pressure Leach Process and provided the required data for the engineering design.

Jan 1, 2008

By E. Ghali, W. Zhang, G. Gabra, N. Sorour, G. Houlachi

The additives polyacrylamide, 1-Butyl-3-methylimidazolium chloride, Tetra-butylammonium bromide, Benzalkonium chloride and chitin are evaluated during zinc electrolysis from synthetic acidic sulphate electrolyte containing Mn2+ ions, in absence and in presence of 0.0055 mg dm-3 of Sb3+ ions. Galvanostatic polarization tests for 2 hours at 50 mA cm-2 and 38oC were carried out to determine the cathodic and anodic potentials, and current efficiency of the deposited zinc. Potentiodynamic polarization and cyclic voltammetry tests have also been employed to study the electrochemical behavior of each additive on the zinc deposit on aluminum electrode. Results showed that, in presence of Sb3+, adding 1 to 3 mg of 1-Butyl-3-methylimidazolium chloride increases the cell voltage by ˜0-7 mV. Current efficiency is increased by ˜4.90-6.40%; power consumption is reduced by ˜147-173 kWh t-1 by adding 1-3 mg, respectively. However, in absence of Sb3+, cell voltage is decreased by ˜7-28 mV, current efficiency is increased by ˜0.70-1.50%; power consumption is reduced by ˜41-47 kWh t-1 by adding 1-3 mg. The effect of the other additives on cell voltage, current efficiency, lead content and morphology of zinc deposit has also been examined. Surface morphology and crystallographic orientation of the deposit was studied using scanning electron microscopic (SEM) and X-ray diffraction (XRD), respectively. The content of lead in the deposit has also been measured using inductively coupled plasma spectroscopy (ICP).

Jan 1, 2015

By Robert A. MacGregor

"Following several months of test work, water leaching in mined-out areas at Stanrock commenced on a production basis in February, 1963. A combination of fast high-pres-sure washing and rewashing of stopes on a predetermined cycle, and the intermittent sprinkling of low-grade heaps, using both fresh water and recirculated acid water, has proved most successful. There was also a correlation of daily sampling data points to a relationship between the leach water grade and the grade of the material being washed, the leaching time and the location along the dip. An increasing tolerance for uranium by the acid-producing bacteria is also indicated. A steady production rate of 10,000 to 12,000 lbs. of u.08 per month is being maintained, with an over-all mine water grade of 0.25 lb. per ton and a pH of 2.3."

Jan 1, 1966