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By Aidan Giblett, Michael McGlynn, Peter Radziszewski

"On the basis that 99% of the energy input into a mill is converted into heat, it is possible to estimate the amount of energy captured in the slurry, the amount that is lost to the environment as well as the possible means to reduce such losses. As a result it becomes possible to estimate the potential amount of energy that can be captured by technologies such as thermoelectric generators or even Sterling engines. Furthermore, it has been suggested that the energy recovery potential dry grinding circuit could be as high as twice that of wet grinding circuits.In this paper, the energy recovery potential of dry grinding will be explored by examining the case of the Newmont Carlin mine dry grinding circuit. The paper will open with a review of the energy recovery potential of a few wet grinding applications followed by a description of the dry grinding circuit and a definition of the control volume around that circuit. A thermodynamic model will be used to estimate the circuit discharge temperature and an estimate of any losses as well as provide an estimate of the potential impact of different means to reduce energy losses. The paper will close with a discussion of the assumptions used in model development."

Jan 1, 2016

By R. Mulligan

"The Cordilleran tin belt extends from the Seward Peninsula in westernmost Alaska to Mexico. Throughout the Canadian section, tin occurrences are mainly confined to a belt along the northeastern fringe of the Western Cordilleran sub-region; the boundary of this sub-region with the Eastern Cordilleran sub-region is most simply defined as the practical eastern limit of granitic and metamorphic rocks. The stratified rocks underlying this restricted belt are mainly late Precambrian and early Paleozoic miogeosynclinal sedimentary rocks, which are more or less metamorphosed but otherwise are generally equivalent to the less severely deformed rocks underlying the Eastern Cordilleran sub-region. They contrast with Late Paleozoic - Mesozoic eugeosynclinal volcanic-sedimentary assemblages farther west, but the granitic intrusions throughout are mainly of Late Mesozoic age. Thus, narrowly defined, the tin belt largely coincides with a lead-zinc-silver metallogenic province, whereas copper deposits characterize the eugeosynclinal regions to the west. In addition to the tin occurrences, which include the Sullivan lead-zinc-silver mine, Canada's only significant producer, the belt contains all the beryllium, most of the tungsten and many Iithophile-type molybdenum occurrences. Several types of occurrences of each metal are represented. Lithium occurrences in the Canadian Cordillera are notably rare, and these few are insignificant."

Jan 1, 1971

By C. Lambert

It has been shown that contacts between host rock and engineered barriers may be critical in the design of deep radioactive waste repositories. Water is expected to reach the interface zone after the re-saturation of the geological massive and its presence may lead to concrete leaching. Such a phenomenon could increase the interface transmissivity and compromise the confinement of radioactive waste. Recent experimental results from Buzzi et al. (2008) have enhanced how concrete leaching can drastically change the mechanical behaviour of such interfaces. Because of the local loss of strength resulting from leaching, shearing resulted in a degradation of the interface asperities. Similarly to rock joints, intact interfaces exhibit a usual contracting-dilating behaviour. On the contrary, depending on the extent of leaching, the degraded interface can display a fully contracting. This paper intends to investigate the influence of concrete leaching on the mechanical behaviour of host rock-concrete interfaces. The leaching process consists in the dissolution of some of the hydrates of the cement paste, leading to a reduction of the strength and Young's modulus. A discrete model has been developed with PFC3D where a simplified interface morphology has been introduced using a saw-tooth description of the asperities.

May 1, 2009

By Allan J. Guse

The primary limiting factor for hoisting capacity from great depths is the self-weight of the typical steel wire ropes used for mine hoisting. Steel wire ropes possess properties making them very suitable for mine hoisting including high strength and durability, but have the negative characteristic of being relatively heavy in comparison with their strength. Also, as hoisting depths increase, the service life of steel wire ropes decreases due to the higher stresses and physical effects on the ropes. The significantly higher strength-to-weight ratio of synthetic ropes compared with steel ropes offers the primary advantage of hoisting a larger payload with a similar size rope and hoisting plant. The beneficial properties of synthetic ropes could be used to improve the overall economics of deep underground mining both for new deep shaft projects and for existing mining operations expanding to deeper orebodies. A research and development program has been initiated to evaluate the suitability of a fully synthetic rope for the mine hoisting application, including rope discard methodology and NDT testing. The three phases/projects are: 1) proof of concept with focus on coilability under load (successfully completed in 2012); 2) high speed and load durability optimization & NDT Development; and 3) in-situ mine trial.

May 1, 2013

By Forrest A. Kerr

Northern British Columbia is a term which probably conveys to various individuals quite different meanings. To the average person it signifies an area of indefinite size and indefinite position which may start at Prince Rupert, Stewart, or somewhere else, and end at Alaska or .the Yukon. Many people, in their conception, fail to encompass in their mind's eye that vast tract of land lying ~o the east of the panhandle of Alaska. Few realize that the area north of an east-west line through Stewart represents more than one-third of the Province and is, of course, the part most appropriately designated as northern British Columbia. This section, more especially the northernmost 100,000 square miles, from political, geographic, and economic viewpoints stands isolated perhaps more than any other part of British Columbia. Unlike the rest of the Province, it has no coast line, being cut off from the Pacific ocean by a narrow strip of Alaska. It is bounded on the north by the Yukon, and on the east by Alberta. In the south this northernmost 100,000 square miles is limited by a divide of rugged mountainous country separating the drainage basins of the Stikine and Liard rivers from those to the south.

Jan 1, 1929

By X. Wu

Tunnel Boring Machines (TBMs) are widely used for tunneling in urban areas because of their high advance rate, precise as-built profile and minimal impact to buildings and traffic on the ground. For a tunnel built by a TBM, there are strict requirements on alignment control and safety. To meet these requirements, it is important to monitor the position of the TBM. In the current practice, the TBM position data, including advance distance and line and level deviations, are reported manually to the managers on a daily basis. To interpret and analyze the position data, the managers also need to refer to various construction drawings. This practice is untimely, inefficient, and error prone for decision making. To improve the current practice, an automatic approach for real-time as-built tunnel product modeling and visualization is proposed, based on TBM position and orientation data autonomously sourced from the Virtual Laser Target Board (VLTB) TBM Guidance System developed at University of Alberta. Related information of the tunnel project, such as the as-designed alignment, soil layers, the ground, existing utility lines, is also visualized together with the model of the as-built tunnel. The modeling algorithm is presented step by step. Its application in a real-life drainage tunnel project is discussed and limitations are also identified.

Aug 1, 2013

By V. Songmene, A. Tahan, J. P. Michaud

The machining of thin wall parts, often used in the aeronautical industry still creates a number of problems, including panel deformation. Quality and productivity are often affected. This study seeks to determine the optimal conditions for cutting in order to guarantee a competitive fabrication of parts while still maintaining quality and delivery deadlines. The studied model (Spar) is a typical structural part used in the assembly of airplane wings. The main objective of this study was to improve two performance aspects: surface quality finish (quality criteria) and the rate of cutting by stock removal (economic criteria). To achieve this objective, we used an evaluation process of the geometrical error issuing from the machine-tool. We also determined the stability zones of the machine-tool's dynamic system. Finally, a series of high-speed machining tests (finishing cuts) were conducted using an experimental structured approach (16 000 - 24 000 rpm). Profile measures of surface roughness and cycle times registered during trials allowed us to establish optimal cutting conditions. Surface roughness improved as well as cutting by stock removal. Four parameters were taken into consideration: axial depth of cut, chip load, spindle speed, and cutting fluid. Finally, the influence of the type of cutting fluid was evaluated to show that it did not significantly affect machining results.

Jan 1, 2006

By Norman R. Ball

"Many people in the mining and metallurgical industries were brought up to embrace Henry Ford's pronouncement that ""History is bunk"" but it is not generally known that the same Henry Ford created and paid for one of the finest technological museums in the Western World. I am aware that many people feel that industry history is something you ask aging executives to do or that history is a clip-andpaste compendium of pictures re-discovered every 25 years or on the occasion of issuing a press release on plant expansion. Moreover, there are many who fear historians as somewhat deranged individuals interested only in corruption, injustice and sensational labour strife. Good history lies somewhere between the controlled P.R. handout and the hysterical attack. Writing good history is a difficult creative act based on the application of experience, insight, wide knowledge and careful reasoning to available evidence. To date, the Canadian mining and metallurgical industries have achieved a great deal but left too little evidence and it is this lack of evidence which must be corrected before it is too late. It is the purpose of this article to stimulate thoughts with regard to archives, one of the more important vehicles for the preservation of such evidence."

Jan 1, 1999

By Edward Thomas

Note. - Securing mine roof through consolidating thin or otherwise incompetent strata to increase overall thickness of the immediate roof beam is a new method of roof support and control which has aroused great interest amongst mining engineers and which is now being experimented with and thoroughly investigated by the United States Bureau of Mines. A paper on Roof Bolting, illustrated by photographs and motion-picture films, will be presented by Edward Thomas, of the U. S. Bureau of Mines, at the forthcoming Annual Meeting of the Mining Society of Nova Scotia. In the following pages, Mr. Thomas describes the methods used in roof bolting as illustrated by the photographs that accompanied his paper. The photographs are supplied through the courtesy of the United States Bureau of Mines, whose willing cooperation with miners and mining engineers in Canada is very well known and even more greatly appreciated. This method of publishing Mr. Thomas's paper is adopted because few, if any, Canadian mining engineers have actually seen installations of roof bolts and it is felt that the best possible presentation of such an interesting subject through the medium of the Bulletin will be attained by publication of the photograps over explanatory captions. - Ed.

Jan 1, 1950

By Dirige. A. P. E.

A study was conducted for an operating mine to determine the appropriateness of its tailings material to be used for the preparation of a low modulus, high density backfill. The research was initiated due to issues arising from increased observations of compressive failure of backfill placed in stopes and inconsistent backfill behaviour (i.e. increased backfill brittleness and modulus). Backfill materials investigated were classified tailings and de-slimed tailings. Characterization of the physical properties of the classified and de-slimed tailings materials was conducted to assess the effect that these material properties would have on the strength and deformation behaviour of high density backfill products made using them. Such behaviour was investigated to determine whether differences in tailings physical properties would influence the strength and modulus character of the backfill materials. Uniaxial (UCS) and consolidated-undrained triaxial compression strength tests were conducted to determine strength performance and deformation behaviour of backfill. This paper presents the results of the backfill material characterization study and how different particle size distributions affected the strength performance and deformation behaviour of the different backfill mixes. It also demonstrates how stress-strain curves generated from material strength tests were used to evaluate variation in high density backfill mix response when such materials were subjected to unconfined and confined (triaxial) compression loading.

Aug 1, 2013

By M. A. Golozar

Partially stabilized zirconia (PSZ) has been proven to be an excellent candidate as a thermal barrier coating (TBC) for hot sections in, for instance, heat or internal engines and gas turbine parts. The main functions of these coatings are reduction of heat losses, reduction of fuel consumption, increasing efficiency, and extending durability and life. One of the main problems involved is wear behavior in the development of such coatings for these applications. Using air plasma spraying (APS) technique, conventional and nanostructured 8 wt % yttria partially stabilized zirconia (Y-PSZ) coatings were deposited on austenitic stainless steel (AISI 304) disc-shaped substrates. The coated substrates were subjected to pin-on-disc wear tests, using 10 mm silicon nitride and zirconia balls as the pin. The coefficient of friction was recorded in real time. The weight loss of coated substrates was measured. Coatings were characterized before and after being subjected to wear testing by various techniques including optical microscopy, scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDX) and X-ray diffraction (XRD). Effects of various experimental parameters such as wear distance, test temperature, and counterface material were also investigated. Results obtained revealed that, regardless of experimental conditions applied, the nanostructured zirconia coating shows better wear and tribological properties than those of the conventional one.

Jan 1, 2005

By Mohammad. M. Khajeh

Rock mechanical properties are important parameters in geomechanical simulation. Considering stochastic heterogeneous models rather than conventional homogeneous layer cake models leads to more realistic simulation results and uncertainty assessment. These heterogeneous models are usually fine scale models generated by geostatistical techniques. Although considering high resolution property models is desirable, geomechanical simulation with a fine scale model is not computationally feasible for full?field, coupled geomechanical-flow simulation. Upscaling of property models is necessary to move from fine scale/high resolution property models to coarser scale/low resolution models appropriate for simulation. Local numerical upscaling was proposed by Khajeh et al. (2012) to describe the macroscopic elastic behavior of complex heterogeneous media and is expanded upon in this work. This numerical technique is not restricted to specific geologies as typical analytical techniques are. Moreover, transversely isotropic deformation is considered rather than the usual assumption of isotropic deformation. To compare the accuracy of the upscaling methodology, in this study shear strain is considered as the geomechanical response of a synthetic facies model and the response of the coarse scale model is compared to other conventional analytical averaging techniques. It is found that the numerical upscaling technique better approximates the geomechanical response of the fine scale model.

Jun 1, 2012

Experimental determination of the response of an AG/SAG mill treating two components of significantly different impact resistance is challenging for two main reasons: firstly, small scale laboratory tests have yet to be confirmed as valid representations of the full scale milling environment, and secondly pilot plant testing requires 10-20 tonnes of ore per scenario which precludes the use of drill core, rendering the process very expensive. In order to mitigate these difficulties, modelling was considered as a potential way forward. However, as the JKSimMet AG/SAG model currently has no capacity to simulate the interaction of two ore types with differing impact resistance, density and/or feed size distributions, an alternative modelling approach was developed. This approach aims to essentially calibrate the AG/SAG process under a set of given conditions, for which survey data and the ore properties of the main components in the feed blend already exist. This paper describes a new conceptual model, which provides a simplified approach for investigating the multi-component behaviour of two ores of differing hardness/SG in a given AG/SAG milling environment, and which can potentially be used for scale-up from laboratory/pilot testwork and geometallurgical estimation of throughput.

Jan 1, 2012

By L. Hacini

The start-up is the most critical phase of the cell life, as an uncontrolled start-up could lead to early infiltrations, instabilities, and in some cases to the cell death. Lots of efforts are put to increase the lifespan of cells, as it has a major impact on both the operating costs and the environmental footprint of the aluminum industry. Obviously, a true size test on a cell is a resources- and time-consuming approach that could be used only to validate mature concepts. Moreover, numerical modelling is a low-cost and versatile tool capable to test a wide range of potential ideas and concepts. In the present article, a thermal electrical mechanical slice model is presented. This model describes the preheating and bath periods of a P155 aluminum cell start-up, as used at the Grande Baie smelter. The impact of sodium diffusion and expansion is also included in the model. This model will be useful to study different problematical issues such as the global behaviour of lining materials, shell and cradle deformations during start-up and several start-up scenarios. Such a model will also be able to answer some interrogations regarding early infiltrations and their impact on the lifespan of the electrolysis cell.

Jan 1, 2011

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

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 R. W. Nice

"The Similkameen Mining Company property is situated about 9 1/2 miles south and west of Princeton B.C. Owned and operated by Newmont Mining Corporation, mining is presently taking place in the Ingerbelle pit. At 15,000 tpd of 0.50% Cu ore the Ingerbelle pit is sufficient for about 8 years. Another 8 years ore supply is available from the old Granby workings of the Copper Mountain property which operated from 1927 to 1957.The pit operations commenced in late 1970 with the concentrator starting in March 1972. Designed and built by Bechtel Corporation under the supervision of Newmont the concentrator's design was based on single-stage crushing and single-stage modified autogenous grinding. The modification was installation of a crusher to crush the critical size build-up. The description of the operation follows.CRUSHERThe primary crusher is an open pocket Allis-Chalmers. 54"" x 74"" gyratory. The basic closed side setting is 8"". The crusher is fed from one side with 100 ton Electra-haul trucks. The crusher pocket discharges to a 96"" wide conveyor belt, then to a 48"" conveyor system including a stacker belt. The crushed product is piled on a stockpile with a capacity of about 30,000 live tons. This stockpile feeds the concentrator."

Jan 1, 1975

By P. J. Gron

"The Samatosum Project is a base and precious metal deposit located in south central British Columbia. A dilute ore reserve of 766, 682 tonnes grading an average 1.1% copper, 3.0% zinc, 1.4% lead, 833 gram per tonne silver and 1.6 gram per tonne gold is available. The base metals occur as tetrahedrite, chalcopyrite, sphalerite and galena. Virtually all of the silver and gold are associated with the tetrahedrite.The mill is operated at a rate of 21 tonnes per hour. Sulphur dioxide is used as a zinc depressant in the grinding circuit. Production of a Cu/Pb/Ag concentrate is accomplished by conventional flotation. This concentrate is then separated into Cu-Ag and Pb concentrates through a reverse flotation circuit utilizing sulphur dioxide, starch and sulphuric acid as lead depressants.The tailings from the Cu/Pb/Ag circuit are treated with copper sulphate to activate the zinc. Production of a zinc concentrate is accomplished by conventional flotation. Dewatering of the concentrates to 6% moisture is done with a LAROX filter press.Tailings effluent is treated with lime and sodium sulphide to precipitate out the heavy metals. The resulting sludge is treated in OYNASAND sand filtration units to produce a quality effluent."

Jan 1, 1990

By M. J. Fairweather, Keith Lee, Naseem Mian

"The initial metallurgical response of the lead flotation circuit at Cominco Alaska's Red Dog Mine was substantially below feasibility expectations. A program of diagnostic mineralogical analysis pointed the way to a number of process improvements, including simplification of the flow sheet and installation of a large flotation column as a lead cleaner. A diagnostic mineralogical analysis of the improved circuit shows that inadvertent activation of both sphalerite and pyrite has been substantially reduced, resulting in significant improvements in metallurgical performance. Directions for further improvements to the circuit performance are suggested by the recent analysis.IntroductionRed Dog is a high-grade, sedimentary exhalative (sedex) deposit with relatively simple mineralogy. The primary non-sulphide gangue minerals are quartz and barite, with minor barium carbonate (witherite). The iron sulphate minerals, siderotil, rosenite and copiapite occur variably throughout the deposit. Mineral texture is variable ranging from liberated sphalerite grains visible to the naked eye to intergrowths, particularly between sphalerite and galena, to less than ten microns. Both pyrite and marcasite are present. To date no enhanced reactivity of marcasite has been observed. For this discussion, ""pyrite"" will be used to refer to both iron sulphide minerals. In common with other sedex deposits, Red Dog contains organic and sulphur impurities."

Jan 1, 1997

By L. W. Hamel

"DUST CONTROL - GRANISLE COPPER LIMITEDINTRODUCTIONGranisle. Copper Limited is located in the north-central region of the Province of British Columbia, approximately 200 road miles north-west of Prince George. Mill startup was in November, 1966, at a rate of 5,000 tons per day, expanded to 13,000 in 1973. The primary crushing rate is 1,200 tons per operating hour, and the secondary 750, and they can be operated jointly or separately.DUST COLLECTION SYSTEMS There are seven dust collection systems ventilating the crushing and grinding complex. The individual pickup points are depicted on Figure 1 -""Crushing Plant Flowsheet"", and Figure 2 - ""Concentrator Flowsheet"", e.g. 1A, 1B, 3C, etc.System No. 1 - Primary Crusher The feed rock box of the Allis-Chalmers superior 42-65 primary crusher is ventilated by 19,000 CFM of air exhausted directly to atmosphere by a Sturtevant 426 M fixed discharge fan.No. Dust Pick Up Point CFM lA Crusher Feed Rock Box 19,000System No. 2 - Primary Crushing and Screening System No. 2 ventilates the primary crushing and screening equipment. A total of 19,000 CFM of air is exhausted by a Sturtevant 426 M fixed discharge fan through a Howden Type S - size 75 cyclone locally modified for wet scrubbing."

Jan 1, 1976