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By D. G. Dixon

A novel technology for leaching copper from primary copper concentrates has been developed at UBC. This patented technology takes advantage of the galvanic couple between pyrite and chalcopyrite to ensure rapid and complete oxidation of chalcopyrite under mild conditions in acidic iron sulfate solution, without the need for microbes, ultrafine grinding, or chemical additives such as chloride, nitrate, or surfactants. Copper recoveries of 98% or greater can be achieved at 80°C under atmospheric conditions in as little as 4 hours of residence time. The process is selective for chalcopyrite over pyrite, generates near-quantitative levels of elemental sulfur, and is fully compatible with conventional solvent extraction and electrowinning of LME Grade A copper cathodes. In this paper, the fundamentals of the Galvanox ? process are reviewed, and selected results of batch leaching tests on various concentrate samples are presented and discussed.

Jan 1, 2007

By Hongyan Qu, Lihui Zheng

"Horizontal wells in coal seams, Qinshui basin, China are prone to wellbore instability problems induced by drilling, completion and production operations due to the presence of natural cleat network, anisotropy with regard to permeability, brittleness and mechanically weak property of the coal rock. The mechanism of wellbore instability in coal seams is very different from that in conventional formations, the traditional wellbore stability study methods therefore, are not proper for wellbore stability analysis in coal.In this study, the mechanism and controlling of wellbore stability of coal seams in the Qinshui basin was investigated through theoretical modeling, laboratory experiment and field operation. Firstly, a new physical model of wellbore stability for highly-cleated coalbed was proposed, considering the combined effect of mechanical mechanism and reservoir characteristics, specifically, taking the effect of reservoir pore pressure in the vicinity of the wellbore on the wellbore stability into account. Then experiments on the triaxial stress evaluation were conducted at laboratory where rock mechanical parameters such as Poisson's ratio, Young's modulus, compressive strength, tensile strength, angle of internal friction and cohesion ability were measured respectively. The in situ stress at different depths in four wells of Zheng 1-303, Zheng 1-308, Zheng 1-309, and Zheng 1-310 in the Zhengzhuang were calculated, and the collapse pressure and formation breakdown pressure were predicted through the theoretical model we developed. Finally, by comparing the maximum collapse pressure and minimum breakdown pressure of the four wells in the coal as well as in the roof and floor of the coal seams, the fluid weight window for safe drilling in each coal seams was determined, and appropriate approaches against anti-sloughing in coal seams, Qinshui basin were applied in the field operation.The wellbore stability was found not only related to the wellbore pressure, but also affected by the pressure in the reservoir through the theoretical model. The fluid weight window for safe drilling in each coal seams varies with the coefficient of wellbore stability in the model. The laboratory experiment results indicate that the roof and floor of 3 # coal in Qinshui basin has high breaking strength, high heterogeneity, and are easy to collapse and breakdown. In addition, the whole rock mineral analysis shows that 3 # coal in the Duanshi block has high clay content, resulting in the phenomenon of hydration swelling as clay encountered water, and leading to unstable coal and extreme large drilling uncertainties. Due to the effect of the unstable rock mechanical properties of the roof and floor formation on the wellbore stabilizing, drilling parameters, drilling fluid performance and BHA were optimized during the drilling process according to the formation properties, rock mechanical properties and drilling techniques in the field operation."

Jan 1, 2015

By Robert A. Brown

"The O'Brien mine is in the west-central part of Cadillac township along the Cadillac 'break', which extends for 7,500 feet from west to east across the property.The ground was staked in 1924 by A. Dumont and W. Hermeston, prospecting for M. J. O'Brien, Limited. The first vein discovered is that now known as No. 1. The No. 4 vein was later exposed on the surface; the other veins known to be present were revealed by underground work and diamond drilling carried out both from the surface and underground.The mine is developed from three vertical shafts: No .. 2 extending from the surface to 2,000 feet; No. 3 from the surface to 1,500 feet; and No. 4 from 2,000 to 3,000 feet. There is on the property a mill of about 200 tons a day capacity, the usual shops, and a townsite housing about forty-five families. Gold production to the end of September, 1944, amounted to 295,824 fine oz. from ore having an average grade of 0.505 oz. a ton. In addition, the mill recovered 3,237 tons of arsenic trioxide having a purity of 83 per cent As2O3.GENERAL GEOLOGYThe four main groups of rocks of the Cadillac area- the Cadillac, Blake River, Kewagama or Pontiac, and Malartic- are found within the boundaries of the property. However, as these rocks have been fully described in · various government reports (1,2,3,4,5,6) and all the known orebodies occur within one group- the Blake River-a detailed description of the geology will be dispensed with here. The known ore deposits lie south of the Cadillac 'break' in a group of rocks that includes 'greenstones', greywackes, conglomerate, porphyries, and a rock of gabbroic composition that may be intrusive. Both flows and tuffs can be recognized in the 'greenstones'. The two bands of porphyry that trend easterly across most of the property have been considered by some observers to be dyke rocks and by others to be flows. Certain evidence points to their being dykes that were intruded as sills considerably prior to the emplacement of the gold-bearing veins, but the possibility of flow origin cannot be fully rejected. North of the talc-chlorite-carbonate schist zone forming the 'break' the rocks are conglomerate and greywacke with iron formation, in which there are no known veins of ore grade. Within the schist zone are minor acid and basic intrusives. The general trend of both bedding and schistosity is a few degrees south of east. The dip is generally vertica1 or steep to the south."

Jan 1, 1954

By Ross Gilders, Leo Cheung, C. David Desjardins

"For the past twenty years significant progress has been made in bacterial leaching. In fact, a recent article in the Northern Miner has cited that nearly all new copper production is based on bioleaching. The bacteria that play the predominant role in bioleaching is an obligate chemolithoautotroph called thiobacillus ferrooxidans. These bacteria thrive in areas rich in sulphide and prefer low acid media. In the simplest sense, they metabolize sulphide converting it to sulphate either as acid or as soluble metal sulphates. This process is well known because these bacteria generate acid mine water. Over the last five( 5) years, we have been carrying out development work on creating optimum bioleach conditions for the extraction of metals from sulphide rich ores and concentrates. Recently, a study was carried out on a byproduct sulphide concentrate produced in a tin flowsheet developed for the Mt. Pleasant Mine of ADEX Mining Corp. The objective was to determine whether a bioleach process might successfully leach this sulphide material which contains copper, zinc, iron and, what is more important, trace metals such as Indium, Gallium, and Bismuth. The current work describes the successful recovery of these metals achieving extractions of more than 80% by applying bioleaching techniques. An overview of this technical program forms the basis of this paper.IntroductionBio-Oxidation of metal sulphides has emerged to be one of the leading edge hydrometallurgical processes for the economic extraction of metals from ore and concentrates. The fundamental process involves the bacterial assisted oxidation of sulphide to sulphate yielding metal sulphates which can be subsequently leached by conventional means. The bacteria that play the predominate role is an obligate chemolithoautotroph named thiobacillus ferrooxidans (TF). These bacteria thrive in areas rich in sulphide and occur naturally worldwide. In fact, TF is responsible for generating acid in water (acid mine water) from exposed sulphide surfaces primarily through the oxidation of pyrite. TF bacteria thrive under the proper conditions of temperature and oxygen supply in the presence of sulphides and populations in excess of a million per millilitre (ml) of solution are achievable. Typically, at room temperature, the bacteria will bio-oxidize in a pH range of 1.0 to 3.0. Today, bio-oxidation has been applied commercially with great success for the extraction of uranium, copper, and gold."

Jan 1, 1996

By Michael K. O’Leary, William D. Coplin

"Risks from political instability and government policies restricting equity ownership, local operations and transfers of payments affect the profitability of foreign mining ventures. More than seat-of-the-pants judgments and old-boy networks are required to anticipate these risks and to take actions appropriate to offsetting them. A system for making political forecasts, called the Prince System, and a series of charts relaying risk s to a production of key minerals will be presented.IntroductionFirm s with extractive operations outside their home country do not have to be told that political stability and government decisions play a big role in the success o f their operations. The takeover of copper firm s in Chile during the Allende administration in 1971 and the recent decision by Venezuela to reduce Reynolds Metals equity share in a smelting operation from 50% to 28% are two examples of hundreds of events that have determined the profitability of extractive operations over the past decade. Both risks and opportunities for international firms seeking to produce and market raw materials are heavily affected by political conditions. While news of political events travel much faster than in the past and host governments are more clever in shaping the risks as well as the opportunities, politics has always been part of the mining business.What has changed is the need to be more systematic in approaching the assessment of political conditions and how it affects business. The increasing costs of extractive operations, the need for long-range planning, the importance of financial arrangements and the world-wide scope of man y firm s' activities require that the assessment be updated continuously and be comparable across different countries and different types of investments. Political risk analysis, the assessment o f macro-political changes and specific governmental decision s on the operations of extractive industries needs to become as systematic and integrated into corporate decision -making as economic analysis has become over the past two decade s."

Jan 1, 1983

By Debasis Deb, Ankur Narang, G. P. Raja Sekhar, Kamal C. Das

"The stability of underground structures made (especially) in jointed rock mass is of the utmost important to designers, engineers and operators. Rock bolting is generally being practised to reinforce excavation walls and roofs by minimizing the movement of rock joints. This study proposes a new analytical model for the prediction of displacements, axial load and shear stress of a fully grouted rock bolt intersected by single or multiple rock joint(s). The governing equations for rock bolt are derived based on the assumption that shear force generated by slippage along the bolt-grout interface has a linear relationship with respect to the relative displacement at the interface. The proposed model is novel compared to the existing literature in the sense that it accounts for rock kinematics as an enriched sum of a continuous part (elastic) and a discontunous (jump) part due to the presence of joint planes. The complete solution of the bolt displacement, axial load and shear stress is derived as a function of the rock displacements, and, it comprises of Heaviside and/or Dirac delta functions in the solution space due to the jump at the intersection point(s) of bolt(s) and joint(s).Our novel solution is able to predict the elastic behavior of a grouted bolt, subjected to opening of the joint planes in pull-out test and also in excavated tunnel. These two cases also serve as benchmarks for grouted rock bolts with multiple joints and can be used for validation of numerical and experimental models. Further, the solution is applied to analyze the behaviour of grouted rock bolt as well as cable bolt installed in circular tunnel, with variations in rock joint(s) opening displacement, shear stiffness in the boltgrout interface and locations of the joint planes. Results indicate that for a specified grout stiffness, the maximum axial load developed in the bolt for discontinuous distribution of rock mass displacement is significantly higher than that of the continuous distribution of rock displacement. This paper provides an analytical interpretation of bolt beaviour considering multiple joint planes with variable joint opening displacements. The results obtained via the analytical method are in line with the corresponding investigation done by other authors. Thus, our analytical treatment can be used to understand bolt behaviour in realistic situations."

Jan 1, 2015

By Brian Lewis

"IntroductionThe leaching method selected for the dissolving of uranium ore depends in part on the physical characteristics of the ore, as well as the uranium mineralization. There are two main methods of leaching employed in uranium circuits in North America, one being ""Carbonate Leaching"" on sandstone, and pitchblende type ores, and ""Acid Leaching"", on quartzite type ores.This chapter deals with the acid leaching of uranium ores found in the Elliot Lake area, using sulphuric acid, for the leaching reagent, and ""pachucas"" for the contactor.The basic leaching process involves the pregrinding of the ore and the mixing of the ore with hot sulphuric acid, the mixture is air agitated, the air being used to oxidize the ore as well as produce agitation. The chemical reaction is as follows: Uranium Oxide + Sulphuric Acid = Uranyl SulphateThe following equations show the actual dissolution of the ""Hexavalent Uranium"", which show that more than one ion or complex of uranium is possible.Uranium DissolutionsI. UO, + 2H-(UOJ + H,O2. (UO,) + SO, = -UO, SO, (Uranyl Sulphate)3. UO, + SO,-(UO, (SO,),)=4. (UO, (SO,),)= -(UO, (SO,),)'Test work carried out in the laboratory as well as in the plants has determined the most efficient methods of extracting the uranium from the ore. A very important factor that has to be determined during initial test work are the amount of acid consumers in the ore. Within the Elliot Lake orebodies are minerals such as chlorite schist, diabase, and basement material, all very high acid consumers, consuming up to 1000 lbs. of acid per ton of ore. Of these minerals only the chlorite schist contain any uranium at all.The following are the operating parameters that have to be controlled in the plant:I. sulphuric acid concentration2. temperature of the mixture3. agitation4. liquid solid ratio5. reaction time6. particle size of ground ore"

Jan 1, 1989

By Mauro Chiesa

An Overview on the Presentation A.The Markets ?Mining Industry ?Capital Markets ?A Six-Cell Matrix of Strategic Options B.De-Risking The Mining Assets ?The Value-Added ?The Assets: Current and in Development ?The Feasibility Study C.(Questions, and answers) Post-Crunch: Some Maxims ?Three Metal Market Models No Longer Prevail ?New models are uncharted: ?be prepared?(ref: Lord B-Powell). ?Capital markets are pricey & uncertain: be your own financier first ?focus on value and on cash-flow (not oz, lbs, tonnes, LOMs, etc) ?Know your banker/financier(and it should know mining) ?In the past, it was ?know your borrower? ?It?s a buyer?s market that wants the ?right deal?: so cast a big net: ?Data must be current, concise and consistent ?3rdparty validation of feasibility work is now a ?passport? ?The risk matrix, with de-risking, is as important as the ?math?

May 1, 2011

The uranium ore processed by the McClean Lake Operation is co-mineralized with niccolite, rammelsbergite and gersdorffite (nickel arsenides). During the strong acid leach process, the majority of the reduced arsenic is oxidized and liberated into the lixiviant solution as As+5. Following uranium extraction, the residual raffinate solution, enriched in As+5, reports to the tailings preparation process. In this process, Fe+3 is first added and mixed with raffinate (pH~1) to achieve a Fe+3/Astotal molar ratio of at least 3. This is followed by two stages of neutralization, using slaked lime to achieve a solution pH of 4, and approximately 7.5, respectively. Synchrotron based x-ray absorption techniques (XANES, EXAFS) applied to neutralized raffinate solids and tailings samples collected from the tailings management facility provide evidence that arsenic has been precipitated as a poorly crystalline form of the mineral scorodite (FeAsO4?2H2O).

Aug 1, 2010

By Richard Morland

The Ekati Safety Guarantee is a conversation that has been taking place at Ekati for the last two years. It is a challenging, confronting, inspiring conversation which encourages people to see and pursue the possibility of guaranteeing that nobody who works at Ekati will be seriously injured or killed at work. The conversation takes us out of the normal, incremental approach to safety improvement; it takes us out of the world of striving, of seeking, of trying, and allows us to stand in, and be a stand for the future possibility of Zero Harm. It requires an unreasonable stand for, and commitment to, our own safety and the safety of our colleagues. A Powerful Conversation The safety guarantee began with conversations between executive team members and has been propagated regularly through the line through management meetings, pre-shift meetings, during workplace inspections, job safety observations, job and project planning, orientation and induction sessions, and when opportunities present themselves. This is a conversation that continues outside of Ekati with family, with government, with community members. It is a stand for safety as a value. The conversation about the safety guarantee is now pervasive at Ekati and forms part of a framework of initiatives that have led to sustained improvement in safety performance. During the last two years, the recordable injury frequency at Ekati has dropped to its lowest level in Ekati?s history. At the same time, job safety observations have increased from 500 per month to 4000 per month, whilst the overall number of people at Ekati has reduced by 30%. It has led to new ways of thinking about the conduct of operations. It influenced the 2008 upgrade of the Ekati process plant, resulting in the development and implementation of a crane lift protocol that eliminated injuries during over 100 lifts in two weeks, in an area of difficult geometry and with multiple entrances. It created space to successfully conduct a challenging commissioning period for the process plant crusher, during which time the machine was disassembled and reassembled several times, without incident or injury. No production pressure was permitted to interfere with this work, in line with our stated aim that we wanted everyone involved to guarantee that they would not be seriously injured or killed?our people had the space to do the work at a pace, and in a way, that guaranteed this outcome.

May 1, 2010

By A. Plumtree

The morphology of environmentally assisted cracks in stressed pipeline steel has been investigated. For a dilute and neutral solution (NS4) simulating ground water in contact with the steel, semi-elliptical cracks grow faster on the surface (2c) than in the depth (a), hence, the aspect ratio (a/c) decreases. This is explained using a deterministic concept since corrosion is dominant and the primary constraint is the conservation of charge. By contrast, when mechanistic conditions prevail, significant growth occurs in the depth. When underloads are imposed in the loading history, temporary accelerations in crack growth occur because corrosion rather than mechanical effects become dominant.

Jan 1, 2005

The morphology of environmentally assisted cracks in stressed pipeline steel has been investigated, For a dilute and neutral solution (NS4) simulating ground water in contact with the steel, semi-elliptical cracks grow faster on the surface (2c) than in the depth (a), hence, the aspect ratio (a/c) decreases, This is explained using a deterministic concept since corrosion is dominant and the primary constraint is the conservation of charge, By contrast, when mechanistic conditions prevail, significant growth occurs in the depth, When underloads are imposed in the loading history, temporary accelerations in crack growth occur because corrosion rather than mechanical effects become dominant.

Jan 1, 2005

By Eiichiro Mizushima

Catalyst systems comprising (Ph3P)AuCH3 and acid co-catalysts were found to be highly efficient for hydration of alkynes to give ketones. Methanol was the best choice of solvents. Introduction Hydration of carbon-carbon unsaturated bonds is one of the environmentally benign routes to the carbon-oxygen bond formation. Hydration of alkynes forming carbonyl compounds, an important variation in this category, is a well known reaction which has been extensively studied. The reaction by acid-catalysis is the most conventional method, while it is applicable only to electron rich acetylenes to obtain satisfactory yields (1,2). The hydration of simple alkynes usually requires another catalyst (co-catalyst), typically a mercury(II) salt (3), which is inconsistent with the guiding principle of Green Chemistry (4).

Oct 1, 2003

Agenda 1.Energy consumption and energy costs ?focus and failings 2.Energy efficiency methodologies, people and supporting tools 3.Energy cost saving case studies from three minerals processing plants 4.The operations team and the supporting role of Operations IT 5.Conclusion: Reducing energy consumption and energy costs There are many good Energy Efficiency Methodologies ?Energy and GHG Emissions, Management Guidance Document, The Mining Association of Canada ?Energy Savings Toolbox ?An Energy Audit Manual and Tool, Canadian Industry Program for Energy Conservation (CIPEC) ?Lean and Energy Toolkit, Achieving Process Excellence Using Less Energy, www.epa.gov/lean ?Energy Efficiency Opportunities Assessment Handbook, www.energyefficiencyopportunities.gov.au

May 1, 2010

By M. Côté, H. Pépin, Y. Richer, C. Gingras

Rolls-Royce Canada has been nominated as a Rolls-Royce Center of Excellence for repair of fan blades in 2003. One of the challenges of the Rolls-Royce Canada Component Repair Center of Excellence team is to reduce cost and time of inspection while ensuring trace ability and quality of the inspection performed on the fan blades. In the context of the dimensional control process optimization, and following the positive conclusions of initial trials carried out in 2003, the technical authorities at RRC have selected the SPG data 3D(TM) technology as a development base for dimensional control programs. The main goal of this development initiative is to develop and support an inspection system to perform the dimensional control and inspection of different components at the Montreal Fan Blade Repair Center of Excellence. The final objective of the program is to build a server platform capable to support different inspection sites within the Montreal facility for the future. This paper presents the certification process of the technology according to the VDI-VDE 2633 certification standards and some results of the fan blade inspection program of the BR 710, BR 715 and TAY according to the JES 195 engineering standards specification.

Jan 1, 2006

By D. Fredlund

The decommissioning of uranium tailings facilities often requires the design of a suitable cover system. In northern climatic environments there is a portion each year that can be considered to be ?inactive? while the remainder of the year can be considered to be ?active?. There are numerous engineering design assumptions required when analyzing both the ?active? and the ?inactive? portions of the year. Cover systems are subjected to complex boundary conditions and nonlinear unsaturated soil properties. The proposed paper describes the steps necessary for the preparation and the analysis of a multi-year climatic database for the design of a cover system in northern environments. The paper also explains how climate can be classified and how observed variations from one year to the next can be taken into consideration in cover design. The results of climatic records at two different sites are used to illustrate conditions that need to be taken into consideration when designing soil cover systems.

Aug 1, 2010

By Z. S. Abisheva

The Zhezkazgan copper sulfide ore deposit in Kazakhstan contains both rhenium and the rare osmium isotope "osmium-187" (187Os) in the high isotopic purity of 99.4 ± 0.2%. This isotope is believed to have originated as a result of the disintegration of one of the rhenium isotopes, according to the reaction: 187Re75 ?> 1870576 + B- + v~ (where B is a 13-particle, v~ is a 3-disintegration antineutrino). The distribution of osmium and rhenium in metallurgical byproducts produced during the recovery of copper from these ores has been studied and process flowsheets for the processing of rhenium and osmium-containing byproducts have been developed.

Jan 1, 2007

Presentation Outline Introduction Deposit Characteristics Geology Grade, Value and Tonnage Estimates 2006 Advanced Program Drilling Bulk Sampling DMS Test Facility 2006 Exploration Summary

May 1, 2006

By B. Huffman

This paper examines several new trends in the design and application of linings for copper melting shaft furnaces including the use of large shapes, monolithic back-up linings and improved refractory engineering to significantly reduce refractory installation time, diamond saw blade costs, fuel and down-time. The net results are shown to be dramatically increased refractory service life, reusable safety linings, elimination of hot spots and lower refractory disposal costs.

Jan 1, 2007

By J. A. Meech

"The technology known as Expert Systems is being used within the minerals industry in a wide variety of problem areas. Applications include diagnosis, prediction, training, monitoring and control. Expert Systems provide a way to program computers to imitate human thinking. The construction of such systems is a straight-forward task that can be quickly learned by novices but can require a lifetime to master.To assist in the understanding and utility of this technology, a special manual bas been prepared which operates on a microcomputer under the MS-Windows environment. The manual covers all aspects of Artificial Intelligence of relevance to Expert Systems. A hypertext system allows users to probe as d•~ply as needed to achieve understanding or to simply skim the surface of the knowledge to obtain a quick overview of subjects. The manual was developed under the sponsorship of the Mineral Sciences Laboratory of CANMET and is available from the Mining and Mineral Process Engineering Department at the University of British Columbia. Annual updates are planned to keep abreast of new developments in this rapidly changing technology. RESUMELa technologie: des Systèmes Experts est utilisée par l'industrie minière pour résoudre une grande variété de problèmes. Les domaines d'application comprennent le diagnostic, la prédiction, la formation, la surveillance et le contrôle des procèdes. Les Systèmes Experts permettent d'écrire des programmes d'ordinateur qui imitent le processus de la pensée humaine. La construction de tels systèmes e:st une tâche qui peut être apprise rapidement mais qui peut prendre des années à maitriser.Pour aider à mieux comprendre et utiliser cette technologie, un manuel spécial opérant sur microordinateur dans l'environnement Windows a été développe. Le manuel couvre tous les aspects de l'intelligence artificielle qui concement les Systèmes Experts. Un système ""hypertexte"" permet à l'utilisateur d'étudier un sujet en profondeur ou de simplement couvrir une grande variété de sujet en surface. Le manuel a été développe avec l'aide financière du Laboratoire des Sciences Minérales de CANMET et est disponible au Département de Génie Minier et Minéralurgique de l'Université de la Colombie Britannique. Des mises à jour annuelles sont prévues de manière à couvrir les changements et nouveautés de cette technologie en évolution."

Jan 1, 1993